1
|
Wang H, Fan L, Choy JS, Kassab GS, Lee LC. Mechanisms of coronary sinus reducer for treatment of myocardial ischemia: in silico study. J Appl Physiol (1985) 2024; 136:1157-1169. [PMID: 38511210 DOI: 10.1152/japplphysiol.00910.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 03/22/2024] Open
Abstract
The coronary sinus reducer (CSR) is an emerging medical device for treating patients with refractory angina, often associated with myocardial ischemia. Patients implanted with CSR have shown positive outcomes, but the underlying mechanisms are unclear. This study sought to understand the mechanisms of CSR by investigating its effects on coronary microcirculation hemodynamics that may help explain the therapy's efficacy. We applied a validated computer model of the coronary microcirculation to investigate how CSR affects hemodynamics under different degrees of coronary artery stenosis. With moderate coronary stenosis, an increase in capillary transit time (CTT) [up to 69% with near-complete coronary sinus (CS) occlusion] is the key change associated with CSR. Because capillaries in the microcirculation can still receive oxygenated blood from the upstream artery with moderate stenosis, the increase in CTT allows more time for the exchange of gases and nutrients, aiding tissue oxygenation. With severe coronary stenosis; however, the redistribution of blood draining from the nonischemic region to the ischemic region (up to 96% with near-complete CS occlusion) and the reduction in capillary flow heterogeneity are the key changes associated with CSR. Because blood draining from the nonischemic region is not completely devoid of O2, the redistribution of blood to the capillaries in the ischemic region by CSR is beneficial especially when little or no oxygenated blood reaches these capillaries. This simulation study provides insights into the mechanisms of CSR in improving clinical symptoms. The mechanisms differ with the severity of the upstream stenosis.NEW & NOTEWORTHY Emerging coronary venous retroperfusion treatments, particularly coronary sinus reducer (CSR) for refractory angina linked to myocardial ischemia, show promise; however, their mechanisms of action are not well understood. We find that CSR's effectiveness varies with the severity of coronary stenosis. In moderate stenosis, CSR improves tissue oxygenation by increasing capillary transit time, whereas in severe stenosis, it redistributes blood from nonischemic to ischemic regions and reduces capillary flow heterogeneity.
Collapse
Affiliation(s)
- Haifeng Wang
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan, United States
| | - Lei Fan
- Joint Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Jenny S Choy
- California Medical Innovations Institute, San Diego, California, United States
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, California, United States
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan, United States
| |
Collapse
|
2
|
Fan L, Wang H, Kassab GS, Lee LC. Review of cardiac-coronary interaction and insights from mathematical modeling. WIREs Mech Dis 2024:e1642. [PMID: 38316634 DOI: 10.1002/wsbm.1642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 12/10/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024]
Abstract
Cardiac-coronary interaction is fundamental to the function of the heart. As one of the highest metabolic organs in the body, the cardiac oxygen demand is met by blood perfusion through the coronary vasculature. The coronary vasculature is largely embedded within the myocardial tissue which is continually contracting and hence squeezing the blood vessels. The myocardium-coronary vessel interaction is two-ways and complex. Here, we review the different types of cardiac-coronary interactions with a focus on insights gained from mathematical models. Specifically, we will consider the following: (1) myocardial-vessel mechanical interaction; (2) metabolic-flow interaction and regulation; (3) perfusion-contraction matching, and (4) chronic interactions between the myocardium and coronary vasculature. We also provide a discussion of the relevant experimental and clinical studies of different types of cardiac-coronary interactions. Finally, we highlight knowledge gaps, key challenges, and limitations of existing mathematical models along with future research directions to understand the unique myocardium-coronary coupling in the heart. This article is categorized under: Cardiovascular Diseases > Computational Models Cardiovascular Diseases > Biomedical Engineering Cardiovascular Diseases > Molecular and Cellular Physiology.
Collapse
Affiliation(s)
- Lei Fan
- Joint Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Haifeng Wang
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, California, USA
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan, USA
| |
Collapse
|
3
|
Wu W, Roby M, Banga A, Oguz UM, Gadamidi VK, Hasini Vasa C, Zhao S, Dasari VS, Thota AK, Tanweer S, Lee C, Kassab GS, Chatzizisis YS. Rapid automated lumen segmentation of coronary optical coherence tomography images followed by 3D reconstruction of coronary arteries. J Med Imaging (Bellingham) 2024; 11:014004. [PMID: 38173655 PMCID: PMC10760146 DOI: 10.1117/1.jmi.11.1.014004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 11/08/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024] Open
Abstract
Purpose Optical coherence tomography has emerged as an important intracoronary imaging technique for coronary artery disease diagnosis as it produces high-resolution cross-sectional images of luminal and plaque morphology. Precise and fast lumen segmentation is essential for efficient OCT morphometric analysis. However, due to the presence of various image artifacts, including side branches, luminal blood artifacts, and complicated lesions, this remains a challenging task. Approach Our research study proposes a rapid automatic segmentation method that utilizes nonuniform rational B-spline to connect limited pixel points and identify the edges of the OCT lumen. The proposed method suppresses image noise and accurately extracts the lumen border with a high correlation to ground truth images based on the area, minimal diameter, and maximal diameter. Results We evaluated the method using 3300 OCT frames from 10 patients and found that it achieved favorable results. The average time taken for automatic segmentation by the proposed method is 0.17 s per frame. Additionally, the proposed method includes seamless vessel reconstruction following the lumen segmentation. Conclusions The developed automated system provides an accurate, efficient, robust, and user-friendly platform for coronary lumen segmentation and reconstruction, which can pave the way for improved assessment of the coronary artery lumen morphology.
Collapse
Affiliation(s)
- Wei Wu
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Merjulah Roby
- The University of Texas San Antonio, Department of Mechanical Engineering, Vascular Biomechanics and Biofluids, San Antonio, Texas, United States
| | - Akshat Banga
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Usama M. Oguz
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Vinay Kumar Gadamidi
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Charu Hasini Vasa
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Shijia Zhao
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Vineeth S. Dasari
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Anjani Kumar Thota
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Sartaj Tanweer
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Changkye Lee
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| | - Ghassan S. Kassab
- California Medical Innovation Institute, San Diego, California, United States
| | - Yiannis S. Chatzizisis
- University of Miami, Miller School of Medicine, Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, Miami, Florida, United States
| |
Collapse
|
4
|
Wang H, Fan L, Choy JS, Kassab GS, Lee LC. Simulation of coronary capillary transit time based on full vascular model of the heart. Comput Methods Programs Biomed 2024; 243:107908. [PMID: 37931581 PMCID: PMC10872892 DOI: 10.1016/j.cmpb.2023.107908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/24/2023] [Accepted: 10/30/2023] [Indexed: 11/08/2023]
Abstract
Capillary transit time (CTT) is a fundamental determinant of gas exchange between blood and tissues in the heart and other organs. Despite advances in experimental techniques, it remains difficult to measure coronary CTT in vivo. Here, we developed a novel computational framework that couples coronary microcirculation with cardiac mechanics in a closed-loop system that enables prediction of hemodynamics in the entire coronary network, including arteries, veins, and capillaries. We also developed a novel "particle-tracking" approach for computing CTT where "virtual tracers" are individually tracked as they traverse the capillary network. Model predictions compare well with blood pressure and flow rate distributions in the arterial network reported in previous studies. Model predictions of transit times in the capillaries (1.21 ± 1.5 s) and entire coronary network (11.8 ± 1.8 s) also agree with measurements. We show that, with increasing coronary artery stenosis (as quantified by fractional flow reserve, FFR), intravascular pressure and flow rate downstream are reduced but remain non-stationary even at 100 % stenosis because some flow (∼3 %) is redistributed from the non-occluded to the occluded territories. Importantly, the model predicts that occlusion of a large artery results in higher CTT. For moderate stenosis (FFR > 0.6), the increase in CTT (from 1.21 s without stenosis to 2.23 s at FFR=0.6) is caused by a decrease in capillary flow rate. In severe stenosis (FFR = 0.1), the increase in CTT to 14.2 s is due to both a decrease in flow rate and an increase in path length taken by "virtual tracers" in the capillary network.
Collapse
Affiliation(s)
- Haifeng Wang
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
| | - Lei Fan
- The Joint Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jenny S Choy
- California Medical Innovations Institute, San Diego, California, USA
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, California, USA
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
5
|
Lunardi M, Louvard Y, Lefèvre T, Stankovic G, Burzotta F, Kassab GS, Lassen JF, Darremont O, Garg S, Koo BK, Holm NR, Johnson TW, Pan M, Chatzizisis YS, Banning AP, Chieffo A, Dudek D, Hildick-Smith D, Garot J, Henry TD, Dangas G, Stone G, Krucoff MW, Cutlip D, Mehran R, Wijns W, Sharif F, Serruys PW, Onuma Y. Definitions and Standardized Endpoints for Treatment of Coronary Bifurcations. EUROINTERVENTION 2023; 19:e807-e831. [PMID: 35583108 PMCID: PMC10687650 DOI: 10.4244/eij-e-22-00018] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The Bifurcation Academic Research Consortium (Bif-ARC) project originated from the need to overcome the paucity of standardization and comparability between studies involving bifurcation coronary lesions. This document is the result of a collaborative effort between academic research organizations and the most renowned interventional cardiology societies focused on bifurcation lesions in Europe, the United States, and Asia. This consensus provides standardized definitions for bifurcation lesions; the criteria to judge the side branch relevance; the procedural, mechanistic, and clinical endpoints for every type of bifurcation study; and the follow-up methods. Considering the complexity of bifurcation lesions and their evaluation, detailed instructions and technical aspects for site and core laboratory analysis of bifurcation lesions are also reported. The recommendations included within this consensus will facilitate pooled analyses and the effective comparison of data in the future, improving the clinical relevance of trials in bifurcation lesions, and the quality of care in this subset of patients.
Collapse
Affiliation(s)
- Mattia Lunardi
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of -Ireland Galway, Galway, Ireland
- Division of Cardiology, Department of Medicine, Verona University Hospital, Verona, Italy
| | - Yves Louvard
- Institut Cardiovasculaire Paris Sud, Massy, France
| | | | - Goran Stankovic
- Department of Cardiology, University Clinical Center of -Serbia and Faculty of Medicine, University of Belgrade, -Belgrade, -Serbia
| | - Francesco Burzotta
- Department of Cardiovascular Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS Università Cattolica del Sacro Cuore, Rome, Italy
| | - Ghassan S Kassab
- California Medical Innovation Institute, San Diego, California, USA
| | - Jens F Lassen
- Department of Cardiology B, Odense Universitets Hospital and University of Southern Denmark, Odense C, Denmark
| | | | - Scot Garg
- Department of Cardiology, Royal Blackburn Hospital, Blackburn, United Kingdom
| | - Bon-Kwon Koo
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| | - Niels R Holm
- Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Thomas W Johnson
- Department of Cardiology, Bristol Heart Institute, University Hospitals Bristol NHSFT & University of Bristol, Bristol, United Kingdom
| | - Manuel Pan
- IMIBIC, Hospital Universitario Reina Sofía, Córdoba, Spain
| | - Yiannis S Chatzizisis
- Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Adrian P Banning
- Oxford Heart Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Alaide Chieffo
- Division of Cardiology, San Raffaele Hospital, Milan, Italy
| | - Dariusz Dudek
- Second Department of Cardiology Jagiellonian University Medical College, Krakow, Poland
| | | | - Jérome Garot
- Institut Cardiovasculaire Paris Sud, Massy, France
| | - Timothy D Henry
- Carl and Edyth Lindner Center for Research and Education at the Christ Hospital, Cincinnati, Ohio, USA
| | - George Dangas
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gregg Stone
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Mitchell W Krucoff
- Division of Cardiology, Duke University Medical Center and Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Donald Cutlip
- Cardiology Division, Beth Israel Deaconess Medical Center, Baim Institute for Clinical Research and Harvard Medical School, Boston, Massachusetts, USA
| | - Roxana Mehran
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - William Wijns
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of -Ireland Galway, Galway, Ireland
- The Lambe Institute for Translational Medicine and CURAM, National University of Ireland Galway, Galway, Ireland
| | - Faisal Sharif
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of -Ireland Galway, Galway, Ireland
| | - Patrick W Serruys
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of -Ireland Galway, Galway, Ireland
- International Centre for Circulatory Health, NHLI, Imperial College, London, United Kingdom
| | - Yoshinobu Onuma
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of -Ireland Galway, Galway, Ireland
| |
Collapse
|
6
|
Gregersen H, Sun D, Field F, Combs W, Christensen P, Mousa H, Moawad FJ, Eisenstein S, Kassab GS. Fecobionics in proctology: review and perspectives. Surg Open Dig Adv 2023; 12:100117. [PMID: 38313319 PMCID: PMC10838111 DOI: 10.1016/j.soda.2023.100117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Fecobionics is a novel integrated technology for assessment of anorectal function. It is a defecatory test with simultaneous measurements of pressures, orientation, and device angle (a proxy of the anorectal angle). Furthermore, the latest Fecobionics prototypes measure diameters (shape) using impedance planimetry during evacuation of the device. The simultaneous measurement of multiple variables in the integrated test allows new metrics to be developed including more advanced novel defecation indices, enabling mechanistic insight in the defecation process at an unprecedented level in patients with anorectal disorders including patients suffering from obstructed defecation, fecal incontinence, and low anterior resection syndrome. The device has the consistency and shape of a normal stool (type 3-4 on the Bristol Stool Form Scale). Fecobionics has been validated on the bench and in animal studies and used in clinical trials to study defecation phenotypes in normal human subjects and patients with obstructed defecation, fecal incontinence, and low anterior resection syndrome after rectal cancer surgery. Subtypes have been defined, especially of patients with obstructed defecation. Furthermore, Fecobionics has been used to monitor biofeedback therapy in patients with fecal incontinence to predict the outcome of the therapy (responder versus non-responder). Most Fecobionics studies showed a closer correlation to symptoms as compared to current technologies for anorectal assessment. The present article outlines previous and ongoing work, and perspectives for future studies in proctology, including in physiological assessment of function, diagnostics, monitoring of therapy, and as a tool for biofeedback therapy.
Collapse
Affiliation(s)
- H Gregersen
- California Medical Innovations Institute, San Diego, California, USA
| | - D Sun
- School of Microelectronics and Communication Engineering, Chongqing University, Chongqing, China
| | - F Field
- S3DT Holdings, San Diego, California, USA
| | - W Combs
- S3DT Holdings, San Diego, California, USA
| | - P Christensen
- Department of Surgery, Aarhus University Hospital, Aarhus, Denmark
| | - H Mousa
- CHOP, University of Pennsylvania, Philadelphia, Pennsylvania
| | - F J Moawad
- Scripps Clinic, Division of Gastroenterology, La Jolla, California, USA
| | - S Eisenstein
- Department of Surgery, University of California San Diego, La Jolla, California, USA
| | - G S Kassab
- California Medical Innovations Institute, San Diego, California, USA
| |
Collapse
|
7
|
Fan L, Choy JS, Lee S, Campbell KS, Wenk JF, Kassab GS, Burkhoff D, Lee LC. An in silico study of the effects of left ventricular assist device on right ventricular function and inter-ventricular interaction. Artif Organs 2023; 47:1831-1847. [PMID: 37746896 PMCID: PMC10964177 DOI: 10.1111/aor.14649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/22/2023] [Accepted: 09/08/2023] [Indexed: 09/26/2023]
Abstract
BACKGROUND Left ventricular assist device (LVAD) is associated with a high incidence of right ventricular (RV) failure, which is hypothesized to be caused by the occurring inter-ventricular interactions when the LV is unloaded. Factors contributing to these interactions are unknown. METHODS We used computer modeling to investigate the impact of the HeartMate 3 LVAD on RV functions. The model was first calibrated against pressure-volume (PV) loops associated with a heart failure (HF) patient and validated against measurements of inter-ventricular interactions in animal experiments. The model was then applied to investigate the effects of LVAD on (1) RV chamber contractility indexed byV 60 derived from its end-systolic PV relationship, and (2) RV diastolic function indexed byV 20 derived from its end-diastolic PV relationship. We also investigated how septal wall thickness and regional contractility affect the impact of LVAD on RV function. RESULTS The impact of LVAD on RV chamber contractility is small at a pump speed lower than 4k rpm. At a higher pump speed between 4k and 9k rpm, however, RV chamber contractility is reduced (by ~3% at 6k rpm and ~10% at 9k rpm). The reduction of RV chamber contractility is greater with a thinner septal wall or with a lower myocardial contractility at the LV free wall, septum, or RV free wall. CONCLUSION RV chamber contractility is reduced at a pump speed higher than 4k rpm, and this reduction is greater with a thinner septal wall or lower regional myocardial contractility. Findings here may have clinical implications in identifying LVAD patients who may suffer from RV failure.
Collapse
Affiliation(s)
- Lei Fan
- Joint Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Jenny S. Choy
- California Medical Innovations Institute, San Diego, California, USA
| | - Sangjin Lee
- Division of Medicine, Advanced Heart Failure and Transplantation, Spectrum Health Meijer Heart & Vascular Institute, Grand Rapids, Michigan, USA
| | - Kenneth S. Campbell
- Physiology and Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Jonathan F. Wenk
- Department of Mechanical Engineering, University of Kentucky, Lexington, Kentucky, USA
| | - Ghassan S. Kassab
- California Medical Innovations Institute, San Diego, California, USA
| | | | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan, USA
| |
Collapse
|
8
|
Wang M, Lu X, Han L, Wang AM, Raju S, Kassab GS. Novel venous balloon for compliance measurement and stent sizing in a post-thrombotic swine model. Front Bioeng Biotechnol 2023; 11:1298621. [PMID: 38076433 PMCID: PMC10702604 DOI: 10.3389/fbioe.2023.1298621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/01/2023] [Indexed: 02/12/2024] Open
Abstract
Objective: Real-time accurate venous lesion characterization is needed during endovenous interventions for stent deployment. The goal of this study is to validate a novel device for venoplasty sizing and compliance measurements. Methods: A compliance measuring sizing balloon (CMSB) uses real-time electrical conductance measurements based on Ohm's Law to measure the venous size and compliance in conjunction with pressure measurement. The sizing accuracy and repeatability of the CMSB system were performed with phantoms on the bench and in a swine model with an induced post thrombotic (PT) stenosis in the common femoral vein of swine. Results: The accuracy and repeatability of the CMSB system were validated with phantom bench studies of known dimensions in the range of venous diameters. In 9 swine (6 experimental and 3 control animals), the luminal cross-sectional areas (CSA) increased heterogeneously along the PT stenosis when the CMSB system was inflated by stepwise pressures. The PT stenosis showed lower compliance compared to the non-PT vein segments (5 mm2 vs. 10 mm2 and 13 mm2 at a pressure change of 40 cm H2O). Compliance had no statistical difference between venous hypertension (VHT) and Control. Compliance at PT stenosis, however, was significantly smaller than that at Control and VHT (p < 0.05, ANOVA). Conclusion: The CMSB system provides accurate, repeatable, real-time measurements of CSA and compliance for assessment of venous lesions to guide interventions. These findings provide the impetus for future first-in-human studies.
Collapse
Affiliation(s)
| | - Xiao Lu
- California Medical Innovations Institute, San Diego, CA, United States
| | - Ling Han
- California Medical Innovations Institute, San Diego, CA, United States
| | - Amy M. Wang
- 3DT Holdings LLC, San Diego, CA, United States
| | - Seshadri Raju
- The Rane Center at St. Dominic’s Hospital, Jackson, MS, United States
| | - Ghassan S. Kassab
- California Medical Innovations Institute, San Diego, CA, United States
| |
Collapse
|
9
|
Samant S, Bakhos JJ, Wu W, Zhao S, Kassab GS, Khan B, Panagopoulos A, Makadia J, Oguz UM, Banga A, Fayaz M, Glass W, Chiastra C, Burzotta F, LaDisa JF, Iaizzo P, Murasato Y, Dubini G, Migliavacca F, Mickley T, Bicek A, Fontana J, West NEJ, Mortier P, Boyers PJ, Gold JP, Anderson DR, Tcheng JE, Windle JR, Samady H, Jaffer FA, Desai NR, Lansky A, Mena-Hurtado C, Abbott D, Brilakis ES, Lassen JF, Louvard Y, Stankovic G, Serruys PW, Velazquez E, Elias P, Bhatt DL, Dangas G, Chatzizisis YS. Artificial Intelligence, Computational Simulations, and Extended Reality in Cardiovascular Interventions. JACC Cardiovasc Interv 2023; 16:2479-2497. [PMID: 37879802 DOI: 10.1016/j.jcin.2023.07.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 07/11/2023] [Accepted: 07/13/2023] [Indexed: 10/27/2023]
Abstract
Artificial intelligence, computational simulations, and extended reality, among other 21st century computational technologies, are changing the health care system. To collectively highlight the most recent advances and benefits of artificial intelligence, computational simulations, and extended reality in cardiovascular therapies, we coined the abbreviation AISER. The review particularly focuses on the following applications of AISER: 1) preprocedural planning and clinical decision making; 2) virtual clinical trials, and cardiovascular device research, development, and regulatory approval; and 3) education and training of interventional health care professionals and medical technology innovators. We also discuss the obstacles and constraints associated with the application of AISER technologies, as well as the proposed solutions. Interventional health care professionals, computer scientists, biomedical engineers, experts in bioinformatics and visualization, the device industry, ethics committees, and regulatory agencies are expected to streamline the use of AISER technologies in cardiovascular interventions and medicine in general.
Collapse
Affiliation(s)
- Saurabhi Samant
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Jules Joel Bakhos
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Wei Wu
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Shijia Zhao
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, California, USA
| | - Behram Khan
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Anastasios Panagopoulos
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Janaki Makadia
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Usama M Oguz
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Akshat Banga
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Muhammad Fayaz
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - William Glass
- Interprofessional Experiential Center for Enduring Learning, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Claudio Chiastra
- PoliTo(BIO)Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Francesco Burzotta
- Department of Cardiovascular Sciences, Università Cattolica Del Sacro Cuore, Rome, Italy
| | - John F LaDisa
- Departments of Biomedical Engineering and Pediatrics - Division of Cardiology, Herma Heart Institute, Children's Wisconsin and the Medical College of Wisconsin, and the MARquette Visualization Lab, Marquette University, Milwaukee, Wisconsin, USA
| | - Paul Iaizzo
- Visible Heart Laboratories, Department of Surgery, University of Minnesota, Minnesota, USA
| | - Yoshinobu Murasato
- Department of Cardiology, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
| | - Gabriele Dubini
- Department of Chemistry, Materials and Chemical Engineering 'Giulio Natta', Politecnico di Milano, Milan, Italy
| | - Francesco Migliavacca
- Department of Chemistry, Materials and Chemical Engineering 'Giulio Natta', Politecnico di Milano, Milan, Italy
| | | | - Andrew Bicek
- Boston Scientific Inc, Marlborough, Massachusetts, USA
| | | | | | | | - Pamela J Boyers
- Interprofessional Experiential Center for Enduring Learning, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Jeffrey P Gold
- Interprofessional Experiential Center for Enduring Learning, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Daniel R Anderson
- Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - James E Tcheng
- Cardiovascular Division, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina, USA
| | - John R Windle
- Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Habib Samady
- Georgia Heart Institute, Gainesville, Georgia, USA
| | - Farouc A Jaffer
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Nihar R Desai
- Section of Cardiovascular Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Alexandra Lansky
- Section of Cardiovascular Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Carlos Mena-Hurtado
- Section of Cardiovascular Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Dawn Abbott
- Cardiovascular Institute, Warren Alpert Medical School at Brown University, Providence, Rhode Island, USA
| | - Emmanouil S Brilakis
- Center for Advanced Coronary Interventions, Minneapolis Heart Institute, Minneapolis, Minnesota, USA
| | - Jens Flensted Lassen
- Department of Cardiology B, Odense University Hospital, Odense, Syddanmark, Denmark
| | - Yves Louvard
- Institut Cardiovasculaire Paris Sud, Massy, France
| | - Goran Stankovic
- Department of Cardiology, Clinical Center of Serbia, Belgrade, Serbia
| | - Patrick W Serruys
- Department of Cardiology, National University of Ireland, Galway, Galway, Ireland
| | - Eric Velazquez
- Section of Cardiovascular Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Pierre Elias
- Seymour, Paul, and Gloria Milstein Division of Cardiology, Columbia University Irving Medical Center, NewYork-Presbyterian Hospital, New York, New York, USA
| | - Deepak L Bhatt
- Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - George Dangas
- Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yiannis S Chatzizisis
- Center for Digital Cardiovascular Innovations, Division of Cardiovascular Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA; Cardiovascular Biology and Biomechanics Laboratory (CBBL), Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA.
| |
Collapse
|
10
|
Choy JS, Hubbard T, Golts EM, Bhatt DL, Navia JA, Kassab GS. Pre-arterialization of coronary veins prior to retroperfusion of ischemic myocardium: percutaneous closure device. Front Cardiovasc Med 2023; 10:1208903. [PMID: 37790598 PMCID: PMC10543752 DOI: 10.3389/fcvm.2023.1208903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 08/31/2023] [Indexed: 10/05/2023] Open
Abstract
Background Chronic coronary retroperfusion to treat myocardial ischemia has previously failed due to edema and hemorrhage of coronary veins suddenly exposed to arterial pressures. The objective of this study was to selectively adapt the coronary veins to become arterialized prior to coronary venous retroperfusion to avoid vascular edema and hemorrhage. Methods and results In 32 animals (Group I = 19 and Group II = 13), the left anterior descending (LAD) artery was occluded using an ameroid occlusion model. In Group I, the great cardiac vein was blocked with suture ligation (Group IA = 11) or with occlusion device (Group IB = 8) to arterialize the venous system within 2 weeks at intermediate pressure (between arterial and venous levels) before a coronary venous bypass graft (CVBG) was implemented through a left internal mammary artery (LIMA) anastomosis. Group II only received the LAD artery occlusion and served as control. Serial echocardiograms showed recovery of left ventricular (LV) function with this adaptation-arterialization approach, with an increase in ejection fraction (EF) in Group I from 38% ± 5% after coronary occlusion to 53% ± 7% eight weeks after CVBG, whereas in Group II the EF never recovered (41% ± 2%-33% ± 7%). The remodeling of the venous system not only allowed restoration of myocardial function when CVBG was implemented but possibly promoted a novel form of "collateralization" between the native arterioles and the newly arterialized venules, which revascularized the ischemic myocardium. Conclusions These findings form a potential rationale for a venous arterialization-revascularization treatment for the refractory angina and the "no-option" patients using a hybrid percutaneous (closure device for arterialization)/surgical approach (CVBG) to revascularize the myocardium.
Collapse
Affiliation(s)
- Jenny S. Choy
- Department of Biomedical Engineering, California Medical Innovations Institute, San Diego, CA, United States
| | | | - Eugene M. Golts
- Division of Cardiovascular and Thoracic Surgery, University of California, San Diego, CA, United States
| | - Deepak L. Bhatt
- Icahn School of Medicine at Mount Sinai Health System, New York, NY, United States
| | - José A. Navia
- Department of Cardiac Surgery, Austral University, Pilar, Buenos Aires, Argentina
| | - Ghassan S. Kassab
- Department of Biomedical Engineering, California Medical Innovations Institute, San Diego, CA, United States
- 3DT Holdings, LLC, San Diego, CA, United States
| |
Collapse
|
11
|
Lu X, Kelley G, Wang M, Guo X, Han L, Kassab GS. Performance of xenogeneic pulmonary visceral pleura as bioprosthetic heart valve cusps in swine. Front Cardiovasc Med 2023; 10:1213398. [PMID: 37600031 PMCID: PMC10433919 DOI: 10.3389/fcvm.2023.1213398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 07/20/2023] [Indexed: 08/22/2023] Open
Abstract
Objective Bovine pericardium is common biological material for bioprosthetic heart valve. There remains a significant need, however, to improve bioprosthetic valves for longer-term outcomes. This study aims to evaluate the chronic performance of bovine pulmonary visceral pleura (PVP) as bioprosthetic valve cusps. Methods The PVP was extracted from the bovine lung and fixed in 0.625% glutaraldehyde overnight at room temperature. The PVP valve cusps for the bioprosthetic valve were tailored using a laser cutter. Three leaflets were sewn onto a nitinol stent. Six PVP bioprosthetic valves were loaded into the test chamber of the heart valve tester to complete 100 million cycles. Six other PVP bioprosthetic valves were transcardially implanted to replace pulmonary artery valve of six pigs. Fluoroscopy and intracardiac echocardiography were used for in vivo assessments. Thrombosis, calcification, inflammation, and fibrosis were evaluated in the terminal study. Histologic analyses were used for evaluations of any degradation or calcification. Results All PVP bioprosthetic valves completed 100 million cycles without significant damage or tears. In vivo assessments showed bioprosthetic valve cusps open and coaptation at four months post-implant. No calcification and thrombotic deposits, inflammation, and fibrosis were observed in the heart or pulmonary artery. The histologic analyses showed complete and compact elastin and collagen fibers in the PVP valve cusps. Calcification-specific stains showed no calcific deposit in the PVP valve cusps. Conclusions The accelerated wear test demonstrates suitable mechanical strength of PVP cusps for heart valve. The swine model demonstrates that the PVP valve cusps are promising for valve replacement.
Collapse
Affiliation(s)
- Xiao Lu
- Department of Bioengineering, California Medical Innovations Institute, San Diego, CA, United States
| | - Greg Kelley
- Department of Research and Development, 3 DT Holdings, LLC, San Diego, CA, United States
| | - Mengjun Wang
- Department of Research and Development, 3 DT Holdings, LLC, San Diego, CA, United States
| | - Xiaomei Guo
- Department of Bioengineering, California Medical Innovations Institute, San Diego, CA, United States
| | - Ling Han
- Department of Bioengineering, California Medical Innovations Institute, San Diego, CA, United States
| | - Ghassan S. Kassab
- Department of Bioengineering, California Medical Innovations Institute, San Diego, CA, United States
| |
Collapse
|
12
|
Guo X, Patel B, Han L, Van Alstine WG, Noblet JN, Chambers SD, Kassab GS. Novel patch biomaterial treatment for colon diverticulosis in swine model. Front Bioeng Biotechnol 2023; 11:1215362. [PMID: 37588135 PMCID: PMC10425590 DOI: 10.3389/fbioe.2023.1215362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/18/2023] [Indexed: 08/18/2023] Open
Abstract
Current leading managements for diverticular disease cannot prevent the recurrence of diverticulitis, bleeding and/or other complications. There is an immediate need for developing new minimal invasive therapeutic strategies to prevent and treat this disease. Through a biomechanical analysis of porcine colon with diverticular lesions, we proposed a novel adhesive patch concept aiming at mechanical reconstruction of the diseased colon wall. This study aims to evaluate the surgical feasibility (safety and efficacy) of pulmonary visceral pleura (PVP) patch therapy using a pig model of diverticulosis. Six female Yucatan miniature pigs underwent collagenase injection (CI) for the development of diverticular lesions. The lesions in each animal either received patch implantation (treated group, n = 40 for 6 pigs) or left intact (untreated group, n = 44 for 6 pigs). The normal colonic wall in each animal received patch implantation at two spots to serve as control (n = 12 for 6 pigs). After 3 months of observation, the performance and safety of the patch treatment were evaluated through macroscopic and histological examination. We found that 95% of pouch-like herniation of the mucosa was prevented from the colon wall with the treatment. The pouch diameter was significantly reduced in the treated group as compared to the untreated group (p < 0.001). The patch application caused a significant increase in the levels of collagen of the colon tissue as compared to the untreated and control groups (p < 0.001). No difference was found in the lymphocyte and macrophage inflammatory infiltrate between the groups. Our results suggest that patch treatment efficiently inhibits the diverticular pouch deformation and promotes the healing of the colon wall with a normal inflammatory response, which may minimize the risk of diverticulosis reoccurrence and complications over time.
Collapse
Affiliation(s)
- Xiaomei Guo
- California Medical Innovations Institute Inc, San Diego, CA, United States
| | - Bhavesh Patel
- California Medical Innovations Institute Inc, San Diego, CA, United States
| | - Ling Han
- California Medical Innovations Institute Inc, San Diego, CA, United States
| | | | | | | | - Ghassan S. Kassab
- California Medical Innovations Institute Inc, San Diego, CA, United States
| |
Collapse
|
13
|
Hashemi J, Peeples H, Kuykendall R, Raju S, Kassab GS. Conduit design with expanding diameter for enhanced flow. Sci Rep 2023; 13:10201. [PMID: 37353535 PMCID: PMC10290114 DOI: 10.1038/s41598-023-36165-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/30/2023] [Indexed: 06/25/2023] Open
Abstract
Conduits are commonly used for treating lesions in arteries and veins. The conventional stents are cylindrical in shape, which increases flow resistance with length. This study presents a design of stents and conduits where the conduit caliber expands gradually to reduce resistance while avoiding flow separation. Inflow was provided from a header tank at two different pressures (i.e., 10 and 25 mm Hg pressure) into a cylindrical or expanding conduit. The initial conduit calibers were 2-, 3-, 4-, and 5-mm and 160-, 310-, and 620-mm lengths in each case. The flow rates of expanding caliber conduits (at a rate of r4-6/cm where r is the initial conduit radius) were compared to traditional cylindrical conduits of constant radius. The expanded caliber yields a significantly increased flow of 16-55% for R4/L expansion, 9-44% for R5/L expansion, and 1-28% for R6/L expansion. Simulated flow models using computational fluid dynamics (CFD) were used to validate and expand the experimental findings. Flow separation was detected for certain simulations by flow pathlines and wall shear stress (WSS) calculations. The results showed that a caliber expansion rate of r6/cm is the optimal rate of expansion for most potential applications with minimum flow separation, lower resistance, and increased flow.
Collapse
Affiliation(s)
- Javad Hashemi
- California Medical Innovation Institute, San Diego, CA, USA
| | - Hunter Peeples
- The RANE Center, 971 Lakeland Drive, Suite 401, Jackson, MS, 39216, USA
| | - Riley Kuykendall
- The RANE Center, 971 Lakeland Drive, Suite 401, Jackson, MS, 39216, USA
| | - Seshadri Raju
- The RANE Center, 971 Lakeland Drive, Suite 401, Jackson, MS, 39216, USA.
| | | |
Collapse
|
14
|
Patel T, Li C, Raissi F, Kassab GS, Gao T, Lee LC. Coupled thermal-hemodynamics computational modeling of cryoballoon ablation for pulmonary vein isolation. Comput Biol Med 2023; 157:106766. [PMID: 36958236 DOI: 10.1016/j.compbiomed.2023.106766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 02/26/2023] [Accepted: 03/07/2023] [Indexed: 03/15/2023]
Abstract
Cryoballoon ablation (CBA) is a cryo-energy based minimally invasive treatment procedure for patients suffering from left atrial (LA) fibrillation. Although this technique has proved to be effective, it is prone to reoccurrences and some serious thermal complications. Also, the factors affecting thermal distribution at the pulmonary vein-antrum junction that are critical to the treatment success is poorly understood. Computer modeling of CBA can resolve this issue and help understand the factors affecting this treatment. To do so, however, numerical challenges associated with the simulation of advection-dominant transport process must be resolved. Here, we describe the development of a thermal-hemodynamics computational framework to simulate incomplete occlusion in a patient-specific LA geometry during CBA. The modeling framework uses the finite element method to predict hemodynamics, thermal distribution, and lesion formation during CBA. An incremental pressure correction scheme is used to decouple velocity and pressure in the Navier-Stokes equation, whereas several stabilization techniques are also applied to overcome numerical instabilities. The framework was implemented using an open-source FE library (FEniCS). We show that model predictions of the hemodynamics in a realistic human LA geometry match well with measurements. The effects of cryoballoon position, pulmonary vein blood velocity and mitral regurgitation on lesion formation during CBA was investigated. For a -700C cryoballoon temperature, the model predicts lesion formation for gaps less than 2.5 mm and increasing efficiency of CBA for higher balloon tissue contact areas. The simulations also predict that lesion formation is not sensitive to variation in pulmonary vein blood velocity and mitral regurgitation. The framework can be applied to optimize CBA in patients for future clinical studies.
Collapse
Affiliation(s)
- Tejas Patel
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | - Chris Li
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | - Farshad Raissi
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | | - Tong Gao
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA; Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
15
|
Dabiri Y, Mahadevan VS, Guccione JM, Kassab GS. Machine learning used for simulation of MitraClip intervention: A proof-of-concept study. Front Genet 2023; 14:1142446. [PMID: 36968590 PMCID: PMC10033889 DOI: 10.3389/fgene.2023.1142446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/27/2023] [Indexed: 03/11/2023] Open
Abstract
Introduction: Severe mitral regurgitation (MR) is a mitral valve disease that can lead to lifethreatening complications. MitraClip (MC) therapy is a percutaneous solution for patients who cannot tolerate surgical solutions. In MC therapy, a clip is implanted in the heart to reduce MR. To achieve optimal MC therapy, the cardiologist needs to foresee the outcomes of different scenarios for MC implantation, including the location of the MC. Although finite element (FE) modeling can simulate the outcomes of different MC scenarios, it is not suitable for clinical usage because it requires several hours to complete.Methods: In this paper, we used machine learning (ML) to predict the outcomes of MC therapy in less than 1 s. Two ML algorithms were used: XGBoost, which is a decision tree model, and a feed-forward deep learning (DL) model. The MC location, the geometrical attributes of the models and baseline stress and MR were the features of the ML models, and the predictions were performed for MR and maximum von Mises stress in the leaflets. The parameters of the ML models were determined to achieve the minimum errors obtained by applying the ML models on the validation set.Results: The results for the test set (not used during training) showed relative agreement between ML predictions and ground truth FE predictions. The accuracy of the XGBoost models were better than DL models. Mean absolute percentage error (MAPE) for the XGBoost predictions were 0.115 and 0.231, and the MAPE for DL predictions were 0.154 and 0.310, for MR and stress, respectively.Discussion: The ML models reduced the FE runtime from 6 hours (on average) to less than 1 s. The accuracy of ML models can be increased by increasing the dataset size. The results of this study have important implications for improving the outcomes of MC therapy by providing information about the outcomes of MC implantation in real-time.
Collapse
Affiliation(s)
- Yaghoub Dabiri
- California Medical Innovations Institute, San Diego, CA, United States
| | | | | | - Ghassan S. Kassab
- California Medical Innovations Institute, San Diego, CA, United States
- *Correspondence: Ghassan S. Kassab,
| |
Collapse
|
16
|
Fan L, Sun Y, Choy JS, Kassab GS, Lee LC. Mechanism of exercise intolerance in heart diseases predicted by a computer model of myocardial demand-supply feedback system. Comput Methods Programs Biomed 2022; 227:107188. [PMID: 36334525 DOI: 10.1016/j.cmpb.2022.107188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/28/2022] [Accepted: 10/16/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE The myocardial demand-supply feedback system plays an important role in augmenting blood supply in response to exercise-induced increased myocardial demand. During this feedback process, the myocardium and coronary blood flow interact bidirectionally at many different levels. METHODS To investigate these interactions, a novel computational framework that considers the closed myocardial demand-supply feedback system was developed. In the framework coupling the systemic circulation of the left ventricle and coronary perfusion with regulation, myocardial work affects coronary perfusion via flow regulation mechanisms (e.g., metabolic regulation) and myocardial-vessel interactions, whereas coronary perfusion affects myocardial contractility in a closed feedback system. The framework was calibrated based on the measurements from healthy subjects under graded exercise conditions, and then was applied to simulate the effects of graded exercise on myocardial demand-supply under different physiological and pathological conditions. RESULTS We found that the framework can recapitulate key features found during exercise in clinical and animal studies. We showed that myocardial blood flow is increased but maximum hyperemia is reduced during exercise, which led to a reduction in coronary flow reserve. For coronary stenosis and myocardial inefficiency, the model predicts that an increase in heart rate is necessary to maintain the baseline cardiac output. Correspondingly, the resting coronary flow reserve is exhausted and the range of heart rate before exhaustion of coronary flow reserve is reduced. In the presence of metabolic regulation dysfunction, the model predicts that the metabolic vasodilator signal is higher at rest, saturates faster during exercise, and as a result, causes quicker exhaustion of coronary flow reserve. CONCLUSIONS Model predictions showed that the coronary flow reserve deteriorates faster during graded exercise, which in turn, suggests a decrease in exercise tolerance for patients with stenosis, myocardial inefficiency and metabolic flow regulation dysfunction. The findings in this study may have clinical implications in diagnosing cardiovascular diseases.
Collapse
Affiliation(s)
- Lei Fan
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
| | - Yuexing Sun
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | - Jenny S Choy
- California Medical Innovations Institute, San Diego, CA, USA
| | | | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
17
|
Labarrere CA, Kassab GS. Glutathione: A Samsonian life-sustaining small molecule that protects against oxidative stress, ageing and damaging inflammation. Front Nutr 2022; 9:1007816. [PMID: 36386929 PMCID: PMC9664149 DOI: 10.3389/fnut.2022.1007816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 10/12/2022] [Indexed: 11/26/2022] Open
Abstract
Many local and systemic diseases especially diseases that are leading causes of death globally like chronic obstructive pulmonary disease, atherosclerosis with ischemic heart disease and stroke, cancer and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 19 (COVID-19), involve both, (1) oxidative stress with excessive production of reactive oxygen species (ROS) that lower glutathione (GSH) levels, and (2) inflammation. The GSH tripeptide (γ- L-glutamyl-L-cysteinyl-glycine), the most abundant water-soluble non-protein thiol in the cell (1-10 mM) is fundamental for life by (a) sustaining the adequate redox cell signaling needed to maintain physiologic levels of oxidative stress fundamental to control life processes, and (b) limiting excessive oxidative stress that causes cell and tissue damage. GSH activity is facilitated by activation of the Kelch-like ECH-associated protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) redox regulator pathway, releasing Nrf2 that regulates expression of genes controlling antioxidant, inflammatory and immune system responses. GSH exists in the thiol-reduced (>98% of total GSH) and disulfide-oxidized (GSSG) forms, and the concentrations of GSH and GSSG and their molar ratio are indicators of the functionality of the cell. GSH depletion may play a central role in inflammatory diseases and COVID-19 pathophysiology, host immune response and disease severity and mortality. Therapies enhancing GSH could become a cornerstone to reduce severity and fatal outcomes of inflammatory diseases and COVID-19 and increasing GSH levels may prevent and subdue these diseases. The life value of GSH makes for a paramount research field in biology and medicine and may be key against systemic inflammation and SARS-CoV-2 infection and COVID-19 disease. In this review, we emphasize on (1) GSH depletion as a fundamental risk factor for diseases like chronic obstructive pulmonary disease and atherosclerosis (ischemic heart disease and stroke), (2) importance of oxidative stress and antioxidants in SARS-CoV-2 infection and COVID-19 disease, (3) significance of GSH to counteract persistent damaging inflammation, inflammaging and early (premature) inflammaging associated with cell and tissue damage caused by excessive oxidative stress and lack of adequate antioxidant defenses in younger individuals, and (4) new therapies that include antioxidant defenses restoration.
Collapse
|
18
|
Labarrere CA, Kassab GS. Glutathione deficiency in the pathogenesis of SARS-CoV-2 infection and its effects upon the host immune response in severe COVID-19 disease. Front Microbiol 2022; 13:979719. [PMID: 36274722 PMCID: PMC9582773 DOI: 10.3389/fmicb.2022.979719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/14/2022] [Indexed: 01/08/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 19 (COVID-19) has numerous risk factors leading to severe disease with high mortality rate. Oxidative stress with excessive production of reactive oxygen species (ROS) that lower glutathione (GSH) levels seems to be a common pathway associated with the high COVID-19 mortality. GSH is a unique small but powerful molecule paramount for life. It sustains adequate redox cell signaling since a physiologic level of oxidative stress is fundamental for controlling life processes via redox signaling, but excessive oxidation causes cell and tissue damage. The water-soluble GSH tripeptide (γ-L-glutamyl-L-cysteinyl-glycine) is present in the cytoplasm of all cells. GSH is at 1–10 mM concentrations in all mammalian tissues (highest concentration in liver) as the most abundant non-protein thiol that protects against excessive oxidative stress. Oxidative stress also activates the Kelch-like ECH-associated protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) redox regulator pathway, releasing Nrf2 to regulate the expression of genes that control antioxidant, inflammatory and immune system responses, facilitating GSH activity. GSH exists in the thiol-reduced and disulfide-oxidized (GSSG) forms. Reduced GSH is the prevailing form accounting for >98% of total GSH. The concentrations of GSH and GSSG and their molar ratio are indicators of the functionality of the cell and its alteration is related to various human pathological processes including COVID-19. Oxidative stress plays a prominent role in SARS-CoV-2 infection following recognition of the viral S-protein by angiotensin converting enzyme-2 receptor and pattern recognition receptors like toll-like receptors 2 and 4, and activation of transcription factors like nuclear factor kappa B, that subsequently activate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) expression succeeded by ROS production. GSH depletion may have a fundamental role in COVID-19 pathophysiology, host immune response and disease severity and mortality. Therapies enhancing GSH could become a cornerstone to reduce severity and fatal outcomes of COVID-19 disease and increasing GSH levels may prevent and subdue the disease. The life value of GSH makes for a paramount research field in biology and medicine and may be key against SARS-CoV-2 infection and COVID-19 disease.
Collapse
|
19
|
Gregersen H, Wang Y, Field F, Wang M, Lo KM, Guo X, Combs W, Kassab GS. Anorectal volume-pressure relations, contraction work, and flow during defecation. Biomech Model Mechanobiol 2022; 21:1613-1621. [PMID: 35908095 PMCID: PMC9633562 DOI: 10.1007/s10237-022-01610-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 07/01/2022] [Indexed: 11/24/2022]
Abstract
Fecobionics is an integrated device that has shown promise for assessment of anorectal function. We used a wireless Fecobionics prototype to visualize defecatory patterns and to compute volume-pressure, contraction work, and flow. Twelve normal subjects were studied. The probe was 10 cm-long and contained pressure sensors and electrodes for impedance planimetry. Pressures, diameters, and volume data during defecation were analyzed. The bag was distended inside rectum to the urge-to-defecate level where after the subjects were asked to evacuate. The contraction work and defecatory flow were computed from the volume changes during expulsion. The minimum anal diameter during the evacuation was 17.6 ± 1.5 mm. The middle diameter recording was 10-20% lower than the front diameter channels and 10-20% bigger than the rear channels. The bag volume at urge correlated with the minimum diameter (r = 0.63). The diameter-pressure and volume-pressure loops were counterclockwise with phases of bag filling, isometric contraction, ejection and anal passage. The defecatory contraction work was 3520 ± 480 mL × cmH2O. The maximum flow during defecation was 302 ± 33 mL/s. The flow was associated with the anal diameter (r = 0.84) but not with the rectoanal pressure gradient (r = 0.14). Volume-pressure loops have a tremendous impact on the understanding of cardiopulmonary pathophysiology. Future studies will shed light on potential clinical impact in defecatory pathophysiology.
Collapse
Affiliation(s)
- Hans Gregersen
- California Medical Innovations Institute, 11107 Roselle St., San Diego, CA, 92121, USA.
| | - Yanmin Wang
- California Medical Innovations Institute, 11107 Roselle St., San Diego, CA, 92121, USA
| | | | | | - Kar Man Lo
- California Medical Innovations Institute, 11107 Roselle St., San Diego, CA, 92121, USA
| | - Xiaomei Guo
- California Medical Innovations Institute, 11107 Roselle St., San Diego, CA, 92121, USA
| | | | - Ghassan S Kassab
- California Medical Innovations Institute, 11107 Roselle St., San Diego, CA, 92121, USA
| |
Collapse
|
20
|
Lu X, Wang M, Han L, Krieger J, Ivers J, Chambers S, Itkin M, Burkhoff D, Kassab GS. Changes of thoracic duct flow and morphology in an animal model of elevated central venous pressure. Front Physiol 2022; 13:798284. [PMID: 36003647 PMCID: PMC9393243 DOI: 10.3389/fphys.2022.798284] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 06/29/2022] [Indexed: 11/13/2022] Open
Abstract
Objective: Investigation of lymph fluid dynamics in thoracic duct during central venous pressure elevation.Background: Lymphatic flow is affected by elevated central venous pressure (CVP) in congestive heart failure. The changes of thoracic duct (TD) lymph flow have not been studied chronically in the setting of elevated CVP. This study is to investigate fluid dynamics and remodeling of the TD in the elevated CVP animal model.Methods: A flow probe was implanted on the swine TD (n = 6) and tricuspid regurgitation (TR) was created by cutting tricuspid chordae percutaneously. Six swine were used as control group animals. The TD flow was measured for 2 weeks (baseline) before TR and 4 weeks postop-TR surgery. Arterial pressure and CVP were measured. The pressure and flow in the TD were measured percutaneously. Histological and morphological analyses were performed.Results: TR resulted in an increase in CVP from 4.2 ± 2.6 to 10.1 ± 4.3 mmHg (p < 0.05). The lymph flow in the TD increased from 0.78 ± 1.06 before TR to 8.8 ± 4.8 ml/min (p < 0.05) 2 days post-TR and remained plateau for 4 weeks, i.e., the TD flow remained approximately 8–11 fold its baseline. Compared to the 8.1 ± 3.2 mmHg control group, the TD average pressures at the lymphovenous junction increased to 14.6 ± 5.7 mmHg in the TR group (p < 0.05). The TD diameter and wall thickness increased from 3.35 ± 0.37 mm and 0.06 ± 0.01 mm in control to 4.32 ± 0.57 mm and 0.26 ± 0.02 mm (p < 0.05) in the TR group, respectively.Conclusion: The elevated CVP results in a significant increase in TD flow and pressure which causes the TD’s outward remodeling and thickening. Our study implicates that the outward remodeling may result in the TD valve incompetence due to failure coaptation of leaflets.
Collapse
Affiliation(s)
- Xiao Lu
- California Medical Innovations Institute, San Diego, CA, United States
| | | | - Ling Han
- California Medical Innovations Institute, San Diego, CA, United States
| | | | | | | | - Max Itkin
- Center for Lymphatic Imaging and Interventions, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
| | - Daniel Burkhoff
- Cardiovascular Research Foundation, New York, NY, United States
| | - Ghassan S. Kassab
- California Medical Innovations Institute, San Diego, CA, United States
- *Correspondence: Ghassan S. Kassab,
| |
Collapse
|
21
|
Lunardi M, Louvard Y, Lefèvre T, Stankovic G, Burzotta F, Kassab GS, Lassen JF, Darremont O, Garg S, Koo BK, Holm NR, Johnson TW, Pan M, Chatzizisis YS, Banning A, Chieffo A, Dudek D, Hildick-Smith D, Garot J, Henry TD, Dangas G, Stone GW, Krucoff MW, Cutlip D, Mehran R, Wijns W, Sharif F, Serruys PW, Onuma Y. Definitions and Standardized Endpoints for Treatment of Coronary Bifurcations. J Am Coll Cardiol 2022; 80:63-88. [PMID: 35597684 DOI: 10.1016/j.jacc.2022.04.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/03/2022] [Accepted: 04/22/2022] [Indexed: 10/18/2022]
Abstract
The Bifurcation Academic Research Consortium (Bif-ARC) project originated from the need to overcome the paucity of standardization and comparability between studies involving bifurcation coronary lesions. This document is the result of a collaborative effort between academic research organizations and the most renowned interventional cardiology societies focused on bifurcation lesions in Europe, the United States, and Asia. This consensus provides standardized definitions for bifurcation lesions; the criteria to judge the side branch relevance; the procedural, mechanistic, and clinical endpoints for every type of bifurcation study; and the follow-up methods. Considering the complexity of bifurcation lesions and their evaluation, detailed instructions and technical aspects for site and core laboratory analysis of bifurcation lesions are also reported. The recommendations included within this consensus will facilitate pooled analyses and the effective comparison of data in the future, improving the clinical relevance of trials in bifurcation lesions, and the quality of care in this subset of patients.
Collapse
Affiliation(s)
- Mattia Lunardi
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of Ireland Galway, Galway, Ireland; Division of Cardiology, Department of Medicine, Verona University Hospital, Verona, Italy
| | - Yves Louvard
- Institut Cardiovasculaire Paris Sud, Massy, France
| | | | - Goran Stankovic
- Department of Cardiology, University Clinical Center of Serbia and Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Francesco Burzotta
- Department of Cardiovascular Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS Università Cattolica del Sacro Cuore, Rome, Italy
| | - Ghassan S Kassab
- California Medical Innovation Institute, San Diego, California, USA
| | - Jens F Lassen
- Department of Cardiology B, Odense Universitets Hospital and University of Southern Denmark, Odense C, Denmark
| | | | - Scot Garg
- Department of Cardiology, Royal Blackburn Hospital, Blackburn, United Kingdom
| | - Bon-Kwon Koo
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
| | - Niels R Holm
- Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Thomas W Johnson
- Department of Cardiology, Bristol Heart Institute, University Hospitals Bristol NHSFT & University of Bristol, Bristol, United Kingdom
| | - Manuel Pan
- IMIBIC, Hospital Universitario Reina Sofía, Córdoba, Spain
| | - Yiannis S Chatzizisis
- Cardiovascular Division, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Adrian Banning
- Oxford Heart Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Alaide Chieffo
- Division of Cardiology, San Raffaele Hospital, Milan, Italy
| | - Dariusz Dudek
- Second Department of Cardiology Jagiellonian University Medical College, Krakow, Poland
| | | | - Jérome Garot
- Institut Cardiovasculaire Paris Sud, Massy, France
| | - Timothy D Henry
- Carl and Edyth Lindner Center for Research and Education at the Christ Hospital, Cincinnati, Ohio, USA
| | - George Dangas
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gregg W Stone
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Mitchell W Krucoff
- Division of Cardiology, Duke University Medical Center and Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Donald Cutlip
- Cardiology Division, Beth Israel Deaconess Medical Center, Baim Institute for Clinical Research and Harvard Medical School, Boston, Massachusetts, USA
| | - Roxana Mehran
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - William Wijns
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of Ireland Galway, Galway, Ireland; The Lambe Institute for Translational Medicine and CURAM, National University of Ireland Galway, Galway, Ireland
| | - Faisal Sharif
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of Ireland Galway, Galway, Ireland
| | - Patrick W Serruys
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of Ireland Galway, Galway, Ireland; International Centre for Circulatory Health, NHLI, Imperial College, London, United Kingdom.
| | - Yoshinobu Onuma
- Department of Cardiology, Saolta Group, Galway University Hospital, Health Service Executive and National University of Ireland Galway, Galway, Ireland
| | | |
Collapse
|
22
|
Gregersen H, Wang Y, Field F, Wang M, Lo KM, Guo X, Combs W, Kassab GS. Feasibility study of defecation studied with a wireless Fecobionics probe in normal subjects. Physiol Rep 2022; 10:e15338. [PMID: 35656707 PMCID: PMC9163794 DOI: 10.14814/phy2.15338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023] Open
Abstract
Several technologies have been developed for assessing anorectal function including the act of defecation. We used a new prototype of the Fecobionics technology, a multi-sensor simulated feces, to visualize defecatory patterns and introduced new metrics for anorectal physiology assessment in normal subjects. Fourteen subjects with normal fecal incontinence and constipation questionnaire scores were studied. The 10-cm-long Fecobionics device provided measurements of axial pressures, orientation, bending, and shape. The Fecobionics bag was distended to the urge-to-defecate level inside rectum where after the subjects were asked to evacuate. Physiological evacuation parameters were assessed. Special attention was paid to the Fecobionics rectoanal pressure gradient (F-RAPG) during evacuation. Anorectal manometry (ARM) and balloon expulsion test (BET) were done as references. The user interface displayed the fine coordination between pressures, orientation, bending angle, and shape. The pressures showed that Fecobionics was expelled in 11.5 s (quartiles 7.5 and 18.8s), which was shorter than the subjectively reported expulsion time of the BET balloon. Six subjects did not expel the BET balloon within 2 min. The F-RAPG was 101 (79-131) cmH2 O, whereas the ARM-RAPG was -28 (-5 to -47) cmH2 0 (p < 0.001). There was no association between the two RAPGs (r2 = 0.19). Fecobionics showed paradoxical contractions in one subject (7%) compared to 12 subjects with ARM (86%). Fecobionics obtained novel physiological data. Defecatory patterns and data are reported and can be used to guide larger-scale studies in normal subjects and patients with defecatory disorders. In accordance with other studies, this Fecobionics study questions the value of the ARM-RAPG.
Collapse
Affiliation(s)
- Hans Gregersen
- California Medical Innovations InstituteSan DiegoCaliforniaUSA
| | - Yanmin Wang
- California Medical Innovations InstituteSan DiegoCaliforniaUSA
| | | | | | - Kar Man Lo
- California Medical Innovations InstituteSan DiegoCaliforniaUSA
| | - Xiaomei Guo
- California Medical Innovations InstituteSan DiegoCaliforniaUSA
| | | | | |
Collapse
|
23
|
Labarrere CA, Kassab GS. Response: Commentary: Pattern Recognition Proteins: First Line of Defense Against Coronaviruses. Front Immunol 2022; 13:853015. [PMID: 35493507 PMCID: PMC9039250 DOI: 10.3389/fimmu.2022.853015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/21/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States
| |
Collapse
|
24
|
Chen Y, Lu X, Luo H, Kassab GS. Aortic Leaflet Stresses Are Substantially Lower Using Pulmonary Visceral Pleura Than Pericardial Tissue. Front Bioeng Biotechnol 2022; 10:869095. [PMID: 35557866 PMCID: PMC9086238 DOI: 10.3389/fbioe.2022.869095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/17/2022] [Indexed: 12/05/2022] Open
Abstract
Background: Porcine heart and bovine pericardium valves, which are collagen-based with relatively little elastin, have been broadly utilized to construct bioprosthetic heart valves (BHVs). With a larger proportion of elastin, the pulmonary visceral pleura (PVP) has greater elasticity and could potentially serve as an advantageous biomaterial for the construction/repair of BHVs. The question of how the aortic valve’s performance is affected by its bending rigidity has not been well studied. Methods: Based on the stress–strain relationships of the pericardium and PVP determined by planar uni-axial tests, a three-dimensional (3D) computational fluid–structure interaction (FSI) framework is employed to numerically investigate the aortic valve’s performance by considering three different cases with Young’s modulus as follows: E=375, 750, and 1500 kPa, respectively. Results: The stroke volumes are 112, 99.6, and 91.4 ml as Young’s modulus increases from 375 to 750 and 1500 kPa, respectively. Peak geometric opening area (GOA) values are 2.3, 2.2, and 2.0 cm2 for E=375, 750, and 1500 kPa, respectively. The maximum value of the aortic leaflet stress is about 271 kPa for E=375 kPa, and it increases to about 383 and 540 kPa for E=750 and 1500 kPa in the belly region at the peak systole, while it reduces from 550 kPa to 450 and 400 kPa for E=375, 750, and 1500 kPa, respectively, at the instant of peak “water-hammer”. Conclusion: A more compliant PVP aortic leaflet valve with a smaller Young’s modulus, E, has a higher cardiac output, larger GOA, and lower hemodynamic resistance. Most importantly, the aortic leaflet stresses are substantially lower in the belly region within the higher compliance PVP aortic valve tissue during the systole phase, even though some stress increase is also found during the fast-closing phase due to the “water-hammer” effect similar to that in the pericardial tissue. Future clinical studies will be conducted to test the hypothesis that the PVP-based valve leaflets with higher compliance will have lower fatigue or calcification rates due to the overall lower stress.
Collapse
Affiliation(s)
- Ye Chen
- California Medical Innovations Institute, San Diego, CA, United States
| | - Xiao Lu
- California Medical Innovations Institute, San Diego, CA, United States
| | - Haoxiang Luo
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Ghassan S. Kassab
- California Medical Innovations Institute, San Diego, CA, United States
- *Correspondence: Ghassan S. Kassab,
| |
Collapse
|
25
|
Hashemi J, Patel B, Chatzizisis YS, Kassab GS. Real time reduced order model for angiography fractional flow reserve. Comput Methods Programs Biomed 2022; 216:106674. [PMID: 35134596 PMCID: PMC8920778 DOI: 10.1016/j.cmpb.2022.106674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/19/2022] [Accepted: 01/30/2022] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND OBJECTIVES Fractional flow reserve (FFR) is the gold standard for quantification of coronary stenosis and pressure wire is the gold standard for measuring FFR. Recently, computational fluid dynamics (CFD) methods have been used to compute FFR less invasively using images obtained from coronary angiography. This approach is, however, computationally intensive and solutions to reduce computation time are clearly required. METHODS We hypothesized that FFR can be calculated instantly using a reduced order model (ROM) derived using response surface method (RSM) for simulation modeling in lieu of the computationally intensive CFD. Specifically, eleven physiological and anatomical factors known to affect FFR were selected as input variables, and Plackett-Burman analysis was performed in conjunction with CFD on model arteries to identify set of variables affecting FFR the most. Based on the Box-Behnken design, a mathematical model was developed to compute FFR using the retained set of variables. RESULTS The model fidelity was tested on a cohort of 90 patients (100 coronary arteries) with known pressure-wire FFR. FFR derived from this ROM had a strong correlation with pressure-wire FFR with sensitivity of 89.4%, specificity of 100% and area under curve of 0.947 (p < 0.05). CONCLUSIONS The ROM method can be used to reliably calculate FFR in patients with coronary stenosis and able to replace time-consuming CFD-based FFR estimation and provide instead a real-time calculation method.
Collapse
Affiliation(s)
- Javad Hashemi
- California Medical Innovation Institute, San Diego, CA, USA
| | - Bhavesh Patel
- California Medical Innovation Institute, San Diego, CA, USA
| | | | | |
Collapse
|
26
|
Lu X, Han L, Kassab GS. Pulmonary Visceral Pleura Biomaterial: Elastin- and Collagen-Based Extracellular Matrix. Front Bioeng Biotechnol 2022; 10:796076. [PMID: 35433658 PMCID: PMC9006517 DOI: 10.3389/fbioe.2022.796076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/28/2022] [Indexed: 12/17/2022] Open
Abstract
Objective: The goal of the study is to determine the structural characteristics, mechanical properties, cytotoxicity, and biocompatibility of the pulmonary visceral pleura (PVP).Background: Collagen and elastin are the major components of the extracellular matrix. The PVP has an abundance of elastin and collagen that can serve as a potential biomaterial for clinical repair and reconstructions.Methods: The PVP was processed from swine and bovine lungs. Chemical analyses were used to determine collagen and elastin contents in the PVPs. Immunofluorescence microscopy was used to analyze the structure of the PVP. The stress–strain relationships and stress relaxation were determined by using the planar uniaxial test. The cytotoxicity of the PVP was tested in cultured cells. In in vivo evaluations, the PVP was implanted in the sciatic nerve and skin of rats.Results: Collagen and elastin contents are abundant in the PVP with larger proportions of elastin than in the bovine pericardium and porcine small intestinal submucosa. A microstructural analysis revealed that the elastin fibers were distributed throughout the PVP and the collagen was distributed mainly in the mesothelial basal lamina. The incremental moduli in stress–strain curves and relaxation moduli in the Maxwell–Wiechert model of PVP were approximately one-tenth of the bovine pericardium and small intestinal submucosa. The minimal cytotoxicity of the PVP was demonstrated. The axons proliferated in the PVP conduit guidance from proximal to distal sciatic nerves of rats. The neo-skin regenerated under the PVP skin substitute within 4 weeks.Conclusions: The PVP is composed of abundant collagen and elastin. The structural characteristics and mechanical compliance of the PVP render a suitable biological material for repair/reconstruction.
Collapse
|
27
|
Vassilev D, Mileva N, Collet C, Nikolov P, Karamfiloff K, Naunov V, Sonck J, Hristova I, Georgieva D, Rigatelli G, Kassab GS, Gil RJ. Determinants of functional significance of coronary bifurcation lesions and clinical outcomes after physiology-guided treatment. Int J Cardiol Heart Vasc 2022; 38:100929. [PMID: 35024426 PMCID: PMC8728425 DOI: 10.1016/j.ijcha.2021.100929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/11/2021] [Accepted: 12/14/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To determine the rate of functionally significant (fractional flow reserve, FFR ≤ 0.80) coronary bifurcation stenoses that are considered anatomically significant based on angiographic estimation and to define predictors of functional significance of stenoses in main vessel and side branch. BACKGROUND To date, the rate of functionally significant stenoses in angiographic significant coronary bifurcation stenoses has not been specifically determined. METHODS Patients with significant angiographic bifurcation lesions defined as diameter stenosis >50% in main vessel and/or side branch were included. FFR was performed in main vessel (MV) and side branch (SB) before and after percutaneous coronary intervention (PCI). The protocol was approved by the local ethics committee. RESULTS Overall, 171 patients with bifurcation lesions were included. Mean FFR in MV was 0.80 ± 0.01 and 0.84 ± 0.09 in SB. 46% (n = 78) of bifurcation lesions were functionally significant when assessed with FFR. Diameter stenosis in main vessel, lesion length, side branch territory and SYNTAX score (SS) were found as predictors for lesion functional severity (main vessel FFR ≤ 0.80). At the time of follow-up, there were no differences between the treated and deferred group regarding rates of all-cause death, cardio-vascular death, MACEs and POCE. CONCLUSION Less than half of all angiographic significant bifurcation lesions were functionally significant when assessed with FFR. There was no difference in clinical outcomes at mean time of three years follow-up in treated and deferred lesion.
Collapse
Affiliation(s)
- Dobrin Vassilev
- “Alexandrovska” University Hospital, Cardiology Department, Medical University Sofia, Bulgaria
- Ruse University “Angel Kanchev”, Department of Healthcare, Studentska-8 Street, Ruse, Bulgaria
| | - Niya Mileva
- “Alexandrovska” University Hospital, Cardiology Department, Medical University Sofia, Bulgaria
- Cardiovascular Center OLV Ziekenhuis, Aalst, Belgium
| | - Carlos Collet
- Cardiovascular Center OLV Ziekenhuis, Aalst, Belgium
| | - Pavel Nikolov
- “Alexandrovska” University Hospital, Cardiology Department, Medical University Sofia, Bulgaria
| | - Kiril Karamfiloff
- “Alexandrovska” University Hospital, Cardiology Department, Medical University Sofia, Bulgaria
| | - Vladimir Naunov
- “Alexandrovska” University Hospital, Cardiology Department, Medical University Sofia, Bulgaria
| | - Jeroen Sonck
- Cardiovascular Center OLV Ziekenhuis, Aalst, Belgium
| | - Irinka Hristova
- Ruse University “Angel Kanchev”, Department of Healthcare, Studentska-8 Street, Ruse, Bulgaria
| | - Despina Georgieva
- Ruse University “Angel Kanchev”, Department of Healthcare, Studentska-8 Street, Ruse, Bulgaria
| | - Gianluca Rigatelli
- Section of Cardiovascular Diagnosis and Endoluminal Interventions, Rovigo General Hospital, Rovigo, Italy
| | | | - Robert J. Gil
- Mossakowski Medical Research Institute, Polish Academy of Science, Warsaw, Poland
| |
Collapse
|
28
|
Fan L, Choy JS, Raissi F, Kassab GS, Lee LC. Optimization of cardiac resynchronization therapy based on a cardiac electromechanics-perfusion computational model. Comput Biol Med 2022; 141:105050. [PMID: 34823858 PMCID: PMC8810745 DOI: 10.1016/j.compbiomed.2021.105050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/10/2021] [Accepted: 11/15/2021] [Indexed: 02/03/2023]
Abstract
Cardiac resynchronization therapy (CRT) is an established treatment for left bundle branch block (LBBB) resulting in mechanical dyssynchrony. Approximately 1/3 of patients with CRT, however, are non-responders. To understand factors affecting CRT response, an electromechanics-perfusion computational model based on animal-specific left ventricular (LV) geometry and coronary vascular networks located in the septum and LV free wall is developed. The model considers contractility-flow and preload-activation time relationships, and is calibrated to simultaneously match the experimental measurements in terms of the LV pressure, volume waveforms and total coronary flow in the left anterior descending and left circumflex territories from 2 swine models under right atrium and right ventricular pacing. The model is then applied to investigate the responses of CRT indexed by peak LV pressure and (dP/dt)max at multiple pacing sites with different degrees of perfusion in the LV free wall. Without the presence of ischemia, the model predicts that basal-lateral endocardial region is the optimal pacing site that can best improve (dP/dt)max by 20%, and is associated with the shortest activation time. In the presence of ischemia, a non-ischemic region becomes the optimal pacing site when coronary flow in the ischemic region fell below 30% of its original value. Pacing at the ischemic region produces little response at that perfusion level. The optimal pacing site is associated with one that optimizes the LV activation time. These findings suggest that CRT response is affected by both pacing site and coronary perfusion, which may have clinical implication in improving CRT responder rates.
Collapse
Affiliation(s)
- Lei Fan
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
| | - Jenny S Choy
- California Medical Innovations Institute, San Diego, CA, USA
| | - Farshad Raissi
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
29
|
Wang Y, Guo X, Sun D, Kassab GS. Roles of Gastric Emptying and Gastrointestinal Transit Following Ileal Interposition in Alleviating Diabetes in Goto-Kakizaki Rats. Front Endocrinol (Lausanne) 2022; 13:849923. [PMID: 35311237 PMCID: PMC8924662 DOI: 10.3389/fendo.2022.849923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 02/03/2022] [Indexed: 12/04/2022] Open
Abstract
OBJECTIVE This study aimed to determine the change of gastrointestinal (GI) emptying time after ileal interposition (IT) and elucidate the role of altered GI peristalsis in diabetic control. MATERIALS AND METHODS Twelve male Goto-Kakizaki rats were randomly divided into IT and sham groups. Body weight and food intake were recorded. Oral glucose tolerance test (OGTT), insulin tolerance test (ITT), plasma glucagon-like peptide-1 (GLP-1), and gastric emptying were measured at baseline and 4 and 8 weeks after operation. At 9 weeks postoperatively, the rats in the IT group were given atropine which can suppress the emptying of stomach and upper intestine, while sham rats were given metoclopramide (to expedite gastric emptying) for 1 week. At week 10 postoperatively, OGTT and GLP-1 were detected. The intestinal transit was tested at postoperative 12 weeks. RESULTS No differences were found between groups at baseline. After operation, the IT rats had lower body weight than sham rats. At 4 and 8 weeks postoperatively, the IT group showed better OGTT and ITT, with significantly elevated GLP-1 relative to sham. After administration of the GI motility drugs, however, the effect of diabetic control for the two groups became similar. The GI transit after IT was significantly slower than sham at all tested time points. CONCLUSIONS Although IT inhibits the GI transit time, the earlier interaction between undigested nutrients and interpositioned ileum promotes gut hormone secretion and thus reduces body weight and alleviates hyperglycemia. A decrease of GI transit of IT rats exacerbates the antidiabetic effects.
Collapse
Affiliation(s)
- Yanmin Wang
- California Medical Innovations Institute, San Diego, CA, United States
| | - Xiaomei Guo
- California Medical Innovations Institute, San Diego, CA, United States
| | - Dong Sun
- Department of General Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Ghassan S. Kassab
- California Medical Innovations Institute, San Diego, CA, United States
- *Correspondence: Ghassan S. Kassab,
| |
Collapse
|
30
|
Dabiri Y, Yao J, Mahadevan VS, Gruber D, Arnaout R, Gentzsch W, Guccione JM, Kassab GS. Mitral Valve Atlas for Artificial Intelligence Predictions of MitraClip Intervention Outcomes. Front Cardiovasc Med 2021; 8:759675. [PMID: 34957251 PMCID: PMC8709129 DOI: 10.3389/fcvm.2021.759675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/03/2021] [Indexed: 11/25/2022] Open
Abstract
Severe mitral regurgitation (MR) is a cardiac disease that can lead to fatal consequences. MitraClip (MC) intervention is a percutaneous procedure whereby the mitral valve (MV) leaflets are connected along the edge using MCs. The outcomes of the MC intervention are not known in advance, i.e., the outcomes are quite variable. Artificial intelligence (AI) can be used to guide the cardiologist in selecting optimal MC scenarios. In this study, we describe an atlas of shapes as well as different scenarios for MC implantation for such an AI analysis. We generated the MV geometrical data from three different sources. First, the patients' 3-dimensional echo images were used. The pixel data from six key points were obtained from three views of the echo images. Using PyGem, an open-source morphing library in Python, these coordinates were used to create the geometry by morphing a template geometry. Second, the dimensions of the MV, from the literature were used to create data. Third, we used machine learning methods, principal component analysis, and generative adversarial networks to generate more shapes. We used the finite element (FE) software ABAQUS to simulate smoothed particle hydrodynamics in different scenarios for MC intervention. The MR and stresses in the leaflets were post-processed. Our physics-based FE models simulated the outcomes of MC intervention for different scenarios. The MR and stresses in the leaflets were computed by the FE models for a single clip at different locations as well as two and three clips. Results from FE simulations showed that the location and number of MCs affect subsequent residual MR, and that leaflet stresses do not follow a simple pattern. Furthermore, FE models need several hours to provide the results, and they are not applicable for clinical usage where the predicted outcomes of MC therapy are needed in real-time. In this study, we generated the required dataset for the AI models which can provide the results in a matter of seconds.
Collapse
Affiliation(s)
| | - Jiang Yao
- Dassault Systemes Simulia Corp, Johnston, RI, United States
| | - Vaikom S Mahadevan
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | | | - Rima Arnaout
- Division of Cardiology, Department of Medicine, University of California, San Francisco, San Francisco, CA, United States.,Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA, United States.,Center for Intelligent Imaging, University of California, San Francisco, San Francisco, CA, United States.,Biological and Medical Informatics, University of California, San Francisco, San Francisco, CA, United States.,Chan Zuckerberg Biohub, University of California, San Francisco, San Francisco, CA, United States
| | | | - Julius M Guccione
- Department of Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Ghassan S Kassab
- Department of Medicine, California Medical Innovations Institute, San Diego, CA, United States
| |
Collapse
|
31
|
Vassilev D, Mileva N, Collet C, Nikolov P, Sokolova K, Karamfiloff K, Naunov V, Sonck J, Rigatelli G, Kassab GS, Gil RJ. Bifurcation functional significance score as predictor of mortality: a validating study. Sci Rep 2021; 11:24308. [PMID: 34934122 PMCID: PMC8692595 DOI: 10.1038/s41598-021-03815-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 10/26/2021] [Indexed: 11/10/2022] Open
Abstract
Considerable progress has been made in the treatment of coronary bifurcation stenosis. Anatomical characteristics of the vessel and lesion, however, fail to give information about the functional significance of the bifurcation stenosis. To the best of our knowledge, there is no study that systematically establishes the baseline functional significance of coronary stenosis and its effect on procedural and clinical outcomes. Patients with significant angiographic bifurcation lesions defined as diameter stenosis > 50% in main vessel and/or side branch were included. FFR was performed in main vessel (MV) and side branch (SB) before and after percutaneous coronary intervention (PCI). 169 patients from Fiesta study (derivation cohort) and 555 patients from prospective bifurcation registry (clinical effect cohort) were analyzed to validate angiographic prediction score (BFSS) used to determine the potentially functional significance of coronary bifurcation stenosis. Bifurcation functional significance score (including the following parameters-SYNTAX ≥ 11, SB/MB BARI score, MV %DS ≥ 55%, main branch (MB) %DS ≥ 65%, lesion length ≥ 25 mm) with a maximum value of 11 was developed. A cut-off value of 6.0 was shown to give the best discriminatory ability-with accuracy 87% (sensitivity 77%, specificity 96%, p < 0.001). There was also a significant difference in all-cause mortality between patients with BFSS ≥ 6.0 vs. BFSS < 6.0-25.5% vs. 18.4%, log-rank p = 0.001 as well as cardiac mortality: BFSS ≥ 6.0 vs. BFSS < 6.0-17.7% vs. 14.5%, log-rank (p = 0.016). The cardiac mortality was significantly lower in patients with smaller absolute SB territory, p = 0.023. An angiographic score (BFSS) with good discriminatory ability to determine the functional significance of coronary bifurcation stenosis was developed. The value for BFSS ≥ 6.0 can be used as a discriminator to define groups with higher risk for all-cause and cardiac mortality. Also, we found that the smaller side branches pose greater mortality risk.
Collapse
Affiliation(s)
- Dobrin Vassilev
- Cardiology Department, Medical University Sofia, "Alexandrovska" University Hospital, Sofia, Bulgaria.
| | - Niya Mileva
- Cardiology Department, Medical University Sofia, "Alexandrovska" University Hospital, Sofia, Bulgaria.
- Cardiovascular Center OLV Ziekenhuis, Moorselbaan 164, 9300, Aalst, Belgium.
| | - Carlos Collet
- Cardiovascular Center OLV Ziekenhuis, Moorselbaan 164, 9300, Aalst, Belgium
| | - Pavel Nikolov
- Cardiology Department, Medical University Sofia, "Alexandrovska" University Hospital, Sofia, Bulgaria
| | - Katerina Sokolova
- Cardiology Department, Medical University Sofia, "Alexandrovska" University Hospital, Sofia, Bulgaria
| | - Kiril Karamfiloff
- Cardiology Department, Medical University Sofia, "Alexandrovska" University Hospital, Sofia, Bulgaria
| | - Vladimir Naunov
- Cardiology Department, Medical University Sofia, "Alexandrovska" University Hospital, Sofia, Bulgaria
| | - Jeroen Sonck
- Cardiovascular Center OLV Ziekenhuis, Moorselbaan 164, 9300, Aalst, Belgium
- Department of Advanced Biomedical Sciences, University of Naples, Federico II, Naples, Italy
| | - Gianluca Rigatelli
- Section of Cardiovascular Diagnosis and Endoluminal Interventions, Rovigo General Hospital, Rovigo, Italy
| | | | - Robert J Gil
- Mossakowski Medical Research Institute, Polish Academy of Science, Warsaw, Poland
| |
Collapse
|
32
|
Fan L, Namani R, Choy JS, Kassab GS, Lee LC. Transmural Distribution of Coronary Perfusion and Myocardial Work Density Due to Alterations in Ventricular Loading, Geometry and Contractility. Front Physiol 2021; 12:744855. [PMID: 34899378 PMCID: PMC8652301 DOI: 10.3389/fphys.2021.744855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/30/2021] [Indexed: 01/09/2023] Open
Abstract
Myocardial supply changes to accommodate the variation of myocardial demand across the heart wall to maintain normal cardiac function. A computational framework that couples the systemic circulation of a left ventricular (LV) finite element model and coronary perfusion in a closed loop is developed to investigate the transmural distribution of the myocardial demand (work density) and supply (perfusion) ratio. Calibrated and validated against measurements of LV mechanics and coronary perfusion, the model is applied to investigate changes in the transmural distribution of passive coronary perfusion, myocardial work density, and their ratio in response to changes in LV contractility, preload, afterload, wall thickness, and cavity volume. The model predicts the following: (1) Total passive coronary flow varies from a minimum value at the endocardium to a maximum value at the epicardium transmurally that is consistent with the transmural distribution of IMP; (2) Total passive coronary flow at different transmural locations is increased with an increase in either contractility, afterload, or preload of the LV, whereas is reduced with an increase in wall thickness or cavity volume; (3) Myocardial work density at different transmural locations is increased transmurally with an increase in either contractility, afterload, preload or cavity volume of the LV, but is reduced with an increase in wall thickness; (4) Myocardial work density-perfusion mismatch ratio at different transmural locations is increased with an increase in contractility, preload, wall thickness or cavity volume of the LV, and the ratio is higher at the endocardium than the epicardium. These results suggest that an increase in either contractility, preload, wall thickness, or cavity volume of the LV can increase the vulnerability of the subendocardial region to ischemia.
Collapse
Affiliation(s)
- Lei Fan
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| | - Ravi Namani
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| | - Jenny S. Choy
- California Medical Innovations Institute, San Diego, CA, United States
| | - Ghassan S. Kassab
- California Medical Innovations Institute, San Diego, CA, United States
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| |
Collapse
|
33
|
Abstract
Obesity is a chronic disease that affects over 795 million people worldwide. Bariatric surgery is an effective therapy to combat the epidemic of clinically severe obesity, but it is only performed in a very small proportion of patients because of the limited surgical indications, the irreversibility of the procedure, and the potential postoperative complications. As an alternative to bariatric surgery, numerous medical devices have been developed for the treatment of morbid obesity and obesity-related disorders. Most devices target restriction of the stomach, but the mechanism of action is likely more than just mechanical restriction. The objective of this review is to integrate the underlying mechanisms of gastric restrictive bariatric devices in obesity and comorbidities. We call attention to the need for future studies on potential mechanisms to shed light on how current gastric volume-restriction bariatric devices function and how future devices and treatments can be further improved to combat the epidemic of obesity.
Collapse
Affiliation(s)
- Yanmin Wang
- California Medical Innovations Institute, San Diego, CA, United States
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States
| |
Collapse
|
34
|
Dabiri AE, Kassab GS. Effects of Cannabis on Cardiovascular System: The Good, the Bad, and the Many Unknowns. Med Cannabis Cannabinoids 2021; 4:75-85. [PMID: 35224427 PMCID: PMC8832198 DOI: 10.1159/000519775] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 09/20/2021] [Indexed: 09/29/2023] Open
Abstract
Cannabis is currently the most consumed illicit substance in the world, and gradual legalization in the USA makes it important to understand the health consequences of the use of this substance. With growing body of evidence that some cannabis ingredients may be beneficial in various aspects of hemostasis, additional research is clearly needed in various clinical areas. In addition to understanding the efficacy, research efforts should also include studies that address any harmful effects of the compounds or administration methods that may result in adverse effects. This review is focused on the cardiometabolic effects of cannabis use. Cardiometabolic diseases are among the leading causes of death in the USA and around the world. The purpose of this review was to provide an overview of the known medicinal benefits of selected cannabis cannabinoids and the known side effects or contraindications. More importantly, we have proposed new questions and signposts in cannabis research to uncover additional medicinal benefits and identify the health hazards with focus on cardiovascular disease.
Collapse
Affiliation(s)
- Ali E. Dabiri
- California Medical Innovation Institute, San Diego, California, USA
- 3DTholdings, San Diego, California, USA
| | | |
Collapse
|
35
|
Zhang JM, Han H, Tan RS, Chai P, Fam JM, Teo L, Chin CY, Ong CC, Low R, Chandola G, Leng S, Huang W, Allen JC, Baskaran L, Kassab GS, Low AFH, Chan MYY, Chan KH, Loh PH, Wong ASL, Tan SY, Chua T, Lim ST, Zhong L. Diagnostic Performance of Fractional Flow Reserve From CT Coronary Angiography With Analytical Method. Front Cardiovasc Med 2021; 8:739633. [PMID: 34746257 PMCID: PMC8564016 DOI: 10.3389/fcvm.2021.739633] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 09/10/2021] [Indexed: 11/15/2022] Open
Abstract
The aim of this study was to evaluate a new analytical method for calculating non-invasive fractional flow reserve (FFRAM) to diagnose ischemic coronary lesions. Patients with suspected or known coronary artery disease (CAD) who underwent computed tomography coronary angiography (CTCA) and invasive coronary angiography (ICA) with FFR measurements from two sites were prospectively recruited. Obstructive CAD was defined as diameter stenosis (DS) ≥50% on CTCA or ICA. FFRAM was derived from CTCA images and anatomical features using analytical method and was compared with computational fluid dynamics (CFD)-based FFR (FFRB) and invasive ICA-based FFR. FFRAM, FFRB, and invasive FFR ≤ 0.80 defined ischemia. A total of 108 participants (mean age 60, range: 30–83 years, 75% men) with 169 stenosed coronary arteries were analyzed. The per-vessel accuracy, sensitivity, specificity, and positive predictive and negative predictive values were, respectively, 81, 75, 86, 81, and 82% for FFRAM and 87, 88, 86, 83, and 90% for FFRB. The area under the receiver operating characteristics curve for FFRAM (0.89 and 0.87) and FFRB (0.90 and 0.86) were higher than both CTCA- and ICA-derived DS (all p < 0.0001) on per-vessel and per-patient bases for discriminating ischemic lesions. The computational time for FFRAM was much shorter than FFRB (2.2 ± 0.9 min vs. 48 ± 36 min, excluding image acquisition and segmentation). FFRAM calculated from a novel and expeditious non-CFD approach possesses a comparable diagnostic performance to CFD-derived FFRB, with a significantly shorter computational time.
Collapse
Affiliation(s)
- Jun-Mei Zhang
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Huan Han
- National Heart Centre Singapore, Singapore, Singapore
| | - Ru-San Tan
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Ping Chai
- Department of Cardiology, National University Heart Centre, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | | | - Lynette Teo
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Diagnostic Imaging, National University Hospital, Singapore, Singapore
| | | | - Ching Ching Ong
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Diagnostic Imaging, National University Hospital, Singapore, Singapore
| | - Ris Low
- National Heart Centre Singapore, Singapore, Singapore
| | | | - Shuang Leng
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Weimin Huang
- Institute for Infocomm Research, Agency for Science, Technology and Research, Singapore, Singapore
| | | | - Lohendran Baskaran
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States
| | - Adrian Fatt Hoe Low
- Department of Cardiology, National University Heart Centre, Singapore, Singapore
| | - Mark Yan-Yee Chan
- Department of Cardiology, National University Heart Centre, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Koo Hui Chan
- Department of Cardiology, National University Heart Centre, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Poay Huan Loh
- Department of Cardiology, National University Heart Centre, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Aaron Sung Lung Wong
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Swee Yaw Tan
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Terrance Chua
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Soo Teik Lim
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Liang Zhong
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| |
Collapse
|
36
|
Chandola G, Zhang JM, Tan RS, Chai P, Teo L, Allen JC, Low R, Huang W, Leng S, Fam JM, Chin CY, Kassab GS, Low AFH, Tan SY, Chua T, Lim ST, Zhong L. Computed Tomography Coronary Angiography and Computational Fluid Dynamics Based Fractional Flow Reserve Before and After Percutaneous Coronary Intervention. Front Bioeng Biotechnol 2021; 9:739667. [PMID: 34557479 PMCID: PMC8452917 DOI: 10.3389/fbioe.2021.739667] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/25/2021] [Indexed: 11/13/2022] Open
Abstract
Invasive fractional flow reserve (FFR) is recommended to guide stent deployment. We previously introduced a non-invasive FFR calculation (FFRB) based on computed tomography coronary angiography (CTCA) with reduced-order computational fluid dynamics (CFD) and resistance boundary conditions. Current study aimed to assess the feasibility and accuracy of FFRB for predicting coronary hemodynamics before and after stenting, with invasive FFR as the reference. Twenty-five patients who had undergone CTCA were prospectively enrolled before invasive coronary angiography (ICA) and FFR-guided percutaneous coronary intervention (PCI) on 30 coronary vessels. Using reduced-order CFD with novel boundary conditions on three-dimensional (3D) patient-specific anatomic models reconstructed from CTCA, we calculated FFRB before and after virtual stenting. The latter simulated PCI by clipping stenotic segments from the 3D coronary models and replacing them with segments to mimic the deployed coronary stents. Pre- and post-virtual stenting FFRB were compared with FFR measured pre- and post-PCI by investigators blinded to FFRB results. Among 30 coronary lesions, pre-stenting FFRB (mean 0.69 ± 0.12) and FFR (mean 0.67 ± 0.13) exhibited good correlation (r = 0.86, p < 0.001) and agreement [mean difference 0.024, 95% limits of agreement (LoA): −0.11, 0.15]. Similarly, post-stenting FFRB (mean 0.84 ± 0.10) and FFR (mean 0.86 ± 0.08) exhibited fair correlation (r = 0.50, p < 0.001) and good agreement (mean difference 0.024, 95% LoA: −0.20, 0.16). The accuracy of FFRB for identifying post-stenting ischemic lesions (FFR ≤ 0.8) (residual ischemia) was 87% (sensitivity 80%, specificity 88%). Our novel FFRB, based on CTCA with reduced-order CFD and resistance boundary conditions, accurately predicts the hemodynamic effects of stenting which may serve as a tool in PCI planning.
Collapse
Affiliation(s)
| | - Jun-Mei Zhang
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Ru-San Tan
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Ping Chai
- Department of Cardiology, National University Heart Centre, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Lynette Teo
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Diagnostic Imaging, National University Hospital, Singapore, Singapore
| | | | - Ris Low
- National Heart Centre Singapore, Singapore, Singapore
| | - Weimin Huang
- Institute for Infocomm Research, Agency for Science, Technology and Research, Singapore, Singapore
| | - Shuang Leng
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | | | - Chee Yang Chin
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States
| | - Adrian Fatt Hoe Low
- Department of Cardiology, National University Heart Centre, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Swee Yaw Tan
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Terrance Chua
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Soo Teik Lim
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Liang Zhong
- National Heart Centre Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| |
Collapse
|
37
|
Abstract
The rapid outbreak of COVID-19 caused by the novel coronavirus SARS-CoV-2 in Wuhan, China, has become a worldwide pandemic affecting almost 204 million people and causing more than 4.3 million deaths as of August 11 2021. This pandemic has placed a substantial burden on the global healthcare system and the global economy. Availability of novel prophylactic and therapeutic approaches are crucially needed to prevent development of severe disease leading to major complications both acutely and chronically. The success in fighting this virus results from three main achievements: (a) Direct killing of the SARS-CoV-2 virus; (b) Development of a specific vaccine, and (c) Enhancement of the host's immune system. A fundamental necessity to win the battle against the virus involves a better understanding of the host's innate and adaptive immune response to the virus. Although the role of the adaptive immune response is directly involved in the generation of a vaccine, the role of innate immunity on RNA viruses in general, and coronaviruses in particular, is mostly unknown. In this review, we will consider the structure of RNA viruses, mainly coronaviruses, and their capacity to affect the lungs and the cardiovascular system. We will also consider the effects of the pattern recognition protein (PRP) trident composed by (a) Surfactant proteins A and D, mannose-binding lectin (MBL) and complement component 1q (C1q), (b) C-reactive protein, and (c) Innate and adaptive IgM antibodies, upon clearance of viral particles and apoptotic cells in lungs and atherosclerotic lesions. We emphasize on the role of pattern recognition protein immune therapies as a combination treatment to prevent development of severe respiratory syndrome and to reduce pulmonary and cardiovascular complications in patients with SARS-CoV-2 and summarize the need of a combined therapeutic approach that takes into account all aspects of immunity against SARS-CoV-2 virus and COVID-19 disease to allow mankind to beat this pandemic killer.
Collapse
Affiliation(s)
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States
| |
Collapse
|
38
|
Kassab GS, Gregersen H, Sun D, Huang Z. Novel bionics developments in gastroenterology: fecobionics assessment of lower GI tract function. Physiol Meas 2021; 42. [PMID: 34190049 DOI: 10.1088/1361-6579/ac023c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 05/17/2021] [Indexed: 11/12/2022]
Abstract
Biomechatronics (bionics) is an applied science that is interdisciplinary between biology and engineering (mechanical, electrical and electronics engineering). Biomechatronics covers a wide area and is probably best known in development of prosthetic limbs, vision aids, robotics and neuroscience. Although the gastrointestinal tract is difficult to study, it is particularly suited for a bionics approach as demonstrated by recent developments. Ingestible capsules that travel the tract and record physiological variables have been used in the clinic. Other examples include sacral nerve stimulators that seek to restore normal anorectal function. Recently, we developed a simulated stool termed fecobionics. It has the shape of normal stool and records a variety of parameters including pressures, bending (anorectal angle) and shape changes during colonic transit and defecation, i.e. it integrates several current tests. Fecobionics has been used to study defecation patterns in large animals as well as in humans (normal subjects and patient groups including patients with symptoms of obstructed defecation and fecal incontinence). Recently, it was applied in a canine colon model where it revealed patterns consistent with shallow waves originating from slow waves generated by the interstitial cells of Cajal. Furthermore, novel analysis such as the rear-front pressure (preload-afterload) diagram and quantification of defecation indices have been developed that enable mechanistic insight. This paper reviews the fecobionics technology and outlines perspectives for future applications.
Collapse
Affiliation(s)
- G S Kassab
- California Medical Innovations Institute, San Diego, CA, United States of America
| | - H Gregersen
- California Medical Innovations Institute, San Diego, CA, United States of America
| | - D Sun
- School of Microelectronics and Communication Engineering, Chongqing University, Chongqing, People's Republic of China
| | - Z Huang
- School of Microelectronics and Communication Engineering, Chongqing University, Chongqing, People's Republic of China
| |
Collapse
|
39
|
Lu X, Han L, Guo X, Wang M, Baradarian S, Golts E, Kassab GS. Novel Biomaterial for Artery Patch in Swine Model With High-Fat Diet. Front Bioeng Biotechnol 2021; 9:679466. [PMID: 34222217 PMCID: PMC8247777 DOI: 10.3389/fbioe.2021.679466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 04/29/2021] [Indexed: 11/27/2022] Open
Abstract
Objective We evaluated swine and bovine pulmonary visceral pleura (PVP) in artery patch-angioplasty in swine model of high-fat diet. Background Arterial patch-angioplasty is frequently used for repair or reconstruction of arteries. An autologous patch is often limited by the number and dimension of donor tissue and can result in donor complications. Furthermore, mechanical mismatch is a cause of poor performance of vascular reconstruction. Here, we introduce a readily available patch biomaterial with similar compliance as native arteries. Methods The PVP was peeled from swine and bovine lungs by hydro-dissection. The swine and bovine PVPs were crosslinked with glutaraldehyde and then sterilized. The swine PVP (sPVP) patches were implanted in the carotid and femoral arteries of six Yorkshire pigs that were fed a regular diet and euthanized at 2 and 4 months postoperative. The bovine PVP (bPVP) patches were implanted in the carotid artery of six Yucatan pigs that were fed a high-fat diet and euthanized at 4 months postoperative. Patency was evaluated by ultrasound and angiography. Neo-endothelium and media were evaluated by histologic examination. Results All arteries in patch-angioplasties remained patent with no adhesions, inflammation, or aneurysms. Biomarkers of endothelial cells (e.g., Factor VIII and eNOS) were detected in the neo-endothelial cells. We observed endothelial cell–cell junctions in the confluent neo-endothelium in the PVP patches. Neo-media composed of vascular smooth muscle developed similar as native arteries. In the hypercholesterolemic model, we observed the accumulation of cholesterol in both arterial tissues and in the neo-vascular tissues in the PVP patches. Protein expressions of lipid transport and metabolism (e.g., APOE-1, ABCA, and PACK9) were also observed in both arterial and neo-vascular tissues. Conclusion The PVP patch-angioplasty overcomes the pitfalls of compliance mismatch of synthetic patches and has a non-thrombogenic surface. The proliferation of vascular cells assembled to generate the neo-endothelium and media in the patch-angioplasties to support long-term patency. The neo-vascular tissue in PVP patch-angioplasty also developed similar cellular functions for lipid transport and metabolism compared with native arteries in hypercholesterolemia.
Collapse
Affiliation(s)
- Xiao Lu
- California Medical Innovations Institute, San Diego, CA, United States
| | - Ling Han
- California Medical Innovations Institute, San Diego, CA, United States
| | - Xiaomei Guo
- California Medical Innovations Institute, San Diego, CA, United States
| | | | - Sam Baradarian
- Scripps Clinic Cardiovascular Surgery, San Diego, CA, United States
| | - Eugene Golts
- University of California San Diego (UCSD) Cardiovascular Surgery, San Diego, CA, United States
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States.,3DT Holdings, San Diego, CA, United States
| |
Collapse
|
40
|
Wu W, Khan B, Sharzehee M, Zhao S, Samant S, Watanabe Y, Murasato Y, Mickley T, Bicek A, Bliss R, Valenzuela T, Iaizzo PA, Makadia J, Panagopoulos A, Burzotta F, Samady H, Brilakis ES, Dangas GD, Louvard Y, Stankovic G, Dubini G, Migliavacca F, Kassab GS, Edelman ER, Chiastra C, Chatzizisis YS. Three dimensional reconstruction of coronary artery stents from optical coherence tomography: experimental validation and clinical feasibility. Sci Rep 2021; 11:12252. [PMID: 34112841 PMCID: PMC8192920 DOI: 10.1038/s41598-021-91458-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/26/2021] [Indexed: 01/09/2023] Open
Abstract
The structural morphology of coronary stents (e.g. stent expansion, lumen scaffolding, strut apposition, tissue protrusion, side branch jailing, strut fracture), and the local hemodynamic environment after stent deployment are key determinants of procedural success and subsequent clinical outcomes. High-resolution intracoronary imaging has the potential to enable the geometrically accurate three-dimensional (3D) reconstruction of coronary stents. The aim of this work was to present a novel algorithm for 3D stent reconstruction of coronary artery stents based on optical coherence tomography (OCT) and angiography, and test experimentally its accuracy, reproducibility, clinical feasibility, and ability to perform computational fluid dynamics (CFD) studies. Our method has the following steps: 3D lumen reconstruction based on OCT and angiography, stent strut segmentation in OCT images, packaging, rotation and straightening of the segmented struts, planar unrolling of the segmented struts, planar stent wireframe reconstruction, rolling back of the planar stent wireframe to the 3D reconstructed lumen, and final stent volume reconstruction. We tested the accuracy and reproducibility of our method in stented patient-specific silicone models using micro-computed tomography (μCT) and stereoscopy as references. The clinical feasibility and CFD studies were performed in clinically stented coronary bifurcations. The experimental and clinical studies showed that our algorithm (1) can reproduce the complex spatial stent configuration with high precision and reproducibility, (2) is feasible in 3D reconstructing stents deployed in bifurcations, and (3) enables CFD studies to assess the local hemodynamic environment within the stent. Notably, the high accuracy of our algorithm was consistent across different stent designs and diameters. Our method coupled with patient-specific CFD studies can lay the ground for optimization of stenting procedures, patient-specific computational stenting simulations, and research and development of new stent scaffolds and stenting techniques.
Collapse
Affiliation(s)
- Wei Wu
- Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Behram Khan
- Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Mohammadali Sharzehee
- Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Shijia Zhao
- Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Saurabhi Samant
- Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Yusuke Watanabe
- Department of Cardiology, Teikyo University Hospital, Tokyo, Japan
| | - Yoshinobu Murasato
- Department of Cardiology, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan
| | | | | | | | - Thomas Valenzuela
- Visible Heart Laboratory, Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Paul A Iaizzo
- Visible Heart Laboratory, Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Janaki Makadia
- Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Anastasios Panagopoulos
- Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Francesco Burzotta
- Department of Cardiovascular Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS Università Cattolica del Sacro Cuore, Rome, Italy
| | - Habib Samady
- School of Medicine, Emory University, Atlanta, GA, USA
| | | | - George D Dangas
- Department of Cardiovascular Medicine, Mount Sinai Hospital, New York City, NY, USA
| | - Yves Louvard
- Institut Cardiovasculaire Paris Sud, Massy, France
| | - Goran Stankovic
- Department of Cardiology, Clinical Center of Serbia, Belgrade, Serbia
| | - Gabriele Dubini
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta,", Politecnico di Milano, Milan, Italy
| | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta,", Politecnico di Milano, Milan, Italy
| | | | - Elazer R Edelman
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Boston, MA, USA
| | - Claudio Chiastra
- PoliToBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Yiannis S Chatzizisis
- Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE, 68198, USA.
| |
Collapse
|
41
|
Hashemi J, Patel B, Chatzizisis YS, Kassab GS. Study of Coronary Atherosclerosis Using Blood Residence Time. Front Physiol 2021; 12:625420. [PMID: 34012404 PMCID: PMC8128163 DOI: 10.3389/fphys.2021.625420] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 04/06/2021] [Indexed: 01/09/2023] Open
Abstract
Computational fluid dynamic-based modeling is commonly used in stenosed and stented coronary artery to characterize blood flow and identify hemodynamics factors that could lead to coronary stenosis. One such factor is the residence time (RT), which is important for investigating stenosis and restenosis progression. The current method to calculate RT, known as the relative residence time (RRT) method, does not provide the original scale of RT and only provides a relative value. We recently introduced a novel method, designated as RT method, based on developing the advection-diffusion equation with a scalar to calculate the absolute residence time. The goal of this study was to compare both methods. Our results show that both could detect regions with a high risk of stenosis and restenosis, but the RT method is also able to show the recirculation zone using pathlines in the lumen and quantify actual RT. Moreover, RT method also provided blood flow pathlines, and is correlated to wall shear stress (WSS), oscillatory shear index (OSI), RRT, and Localized Normalized Helicity (LNH) which are other critical factors to gauge stenosis severity and assess stenting in bifurcations coronary.
Collapse
Affiliation(s)
- Javad Hashemi
- California Medical Innovation Institute, San Diego, CA, United States
| | - Bhavesh Patel
- California Medical Innovation Institute, San Diego, CA, United States
| | - Yiannis S Chatzizisis
- Cardiovascular Division, University of Nebraska Medical Center, Omaha, NE, United States
| | - Ghassan S Kassab
- California Medical Innovation Institute, San Diego, CA, United States
| |
Collapse
|
42
|
Itkin M, Rockson SG, Witte MH, Burkhoff D, Phillips A, Windsor JA, Kassab GS, Hur S, Nadolski G, Pabon-Ramos WM, Rabinowitz D, White SB. Research Priorities in Lymphatic Interventions: Recommendations from a Multidisciplinary Research Consensus Panel. J Vasc Interv Radiol 2021; 32:762.e1-762.e7. [PMID: 33610432 DOI: 10.1016/j.jvir.2021.01.269] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/06/2021] [Accepted: 01/16/2021] [Indexed: 11/26/2022] Open
Abstract
Recognizing the increasing importance of lymphatic interventions, the Society of Interventional Radiology Foundation brought together a multidisciplinary group of key opinion leaders in lymphatic medicine to define the priorities in lymphatic research. On February 21, 2020, SIRF convened a multidisciplinary Research Consensus Panel (RCP) of experts in the lymphatic field. During the meeting, the panel and audience discussed potential future research priorities. The panelists ranked the discussed research priorities based on clinical relevance, overall impact, and technical feasibility. The following research topics were prioritized by RCP: lymphatic decompression in patients with congestive heart failure, detoxification of thoracic duct lymph in acute illness, development of newer agents for lymphatic imaging, characterization of organ-based lymph composition, and development of lymphatic interventions to treat ascites in liver cirrhosis. The RCP priorities underscored that the lymphatic system plays an important role not only in the intrinsic lymphatic diseases but in conditions that traditionally are not considered to be lymphatic such as congestive heart failure, liver cirrhosis, and critical illness. The advancement of the research in these areas will lead the field of lymphatic interventions to the next level.
Collapse
Affiliation(s)
- Maxim Itkin
- Penn Center for Lymphatic Disorders, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
| | - Stanley G Rockson
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California
| | - Marlys H Witte
- University of Arizona College of Medicine Tucson Arizona, International Society of Lymphology, Tuscon, Arizona
| | | | - Anthony Phillips
- Applied Surgery and Metabolism Laboratory, Surgical and Translational Research Centre, School of Biological Sciences & Dept. of Surgery, Auckland University, Auckland, New Zealand
| | - John A Windsor
- Surgery and Director Surgical and Translational Research Centre, University of Auckland, New Zealand
| | | | - Saebeom Hur
- Department of Radiology, Seoul National University Hospital and Seoul National University College of Medicine, Seoul, South Korea
| | - Gregory Nadolski
- Penn Center for Lymphatic Disorders, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Waleska M Pabon-Ramos
- Pediatric Interventional Radiology, Department of Radiology, Duke University Medical Center, Durham, North Carolina
| | - Debbie Rabinowitz
- Department of Medical Imaging, Division of Interventional Radiology, Nemours/duPont Hospital for Children, Radiology and Pediatrics Sidney Kimmel Medical College at Thomas Jefferson University, Wilmington, Delaware
| | - Sarah B White
- Clinical Research and Registries Division, SIR Foundation, Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| |
Collapse
|
43
|
Fan L, Namani R, Choy JS, Awakeem Y, Kassab GS, Lee LC. Role of coronary flow regulation and cardiac-coronary coupling in mechanical dyssynchrony associated with right ventricular pacing. Am J Physiol Heart Circ Physiol 2020; 320:H1037-H1054. [PMID: 33356963 DOI: 10.1152/ajpheart.00549.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mechanical dyssynchrony (MD) affects left ventricular (LV) mechanics and coronary perfusion. To understand the multifactorial effects of MD, we developed a computational model that bidirectionally couples the systemic circulation with the LV and coronary perfusion with flow regulation. In the model, coronary flow in the left anterior descending (LAD) and left circumflex (LCX) arteries affects the corresponding regional contractility based on a prescribed linear LV contractility-coronary flow relationship. The model is calibrated with experimental measurements of LV pressure and volume, as well as LAD and LCX flow rate waveforms acquired under regulated and fully dilated conditions from a swine under right atrial (RA) pacing. The calibrated model is applied to simulate MD. The model can simultaneously reproduce the reduction in mean LV pressure (39.3%), regulated flow (LAD: 7.9%; LCX: 1.9%), LAD passive flow (21.6%), and increase in LCX passive flow (15.9%). These changes are associated with right ventricular pacing compared with RA pacing measured in the same swine only when LV contractility is affected by flow alterations with a slope of 1.4 mmHg/mL2 in a contractility-flow relationship. In sensitivity analyses, the model predicts that coronary flow reserve (CFR) decreases and increases in the LAD and LCX with increasing delay in LV free wall contraction. These findings suggest that asynchronous activation associated with MD impacts 1) the loading conditions that further affect the coronary flow, which may explain some of the changes in CFR, and 2) the coronary flow that reduces global contractility, which contributes to the reduction in LV pressure.NEW & NOTEWORTHY A computational model that couples the systemic circulation of the left ventricular (LV) and coronary perfusion with flow regulation is developed to study the effects of mechanical dyssynchrony. The delayed contraction in the LV free wall with respect to the septum has a significant effect on LV function and coronary flow reserve.
Collapse
Affiliation(s)
- Lei Fan
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan
| | - Ravi Namani
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan
| | - Jenny S Choy
- California Medical Innovation Institute, San Diego, California
| | - Yousif Awakeem
- California Medical Innovation Institute, San Diego, California
| | | | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan
| |
Collapse
|
44
|
Dabiri Y, Van der Velden A, Sack KL, Choy JS, Guccione JM, Kassab GS. Application of feed forward and recurrent neural networks in simulation of left ventricular mechanics. Sci Rep 2020; 10:22298. [PMID: 33339836 PMCID: PMC7749109 DOI: 10.1038/s41598-020-79191-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 11/19/2020] [Indexed: 11/25/2022] Open
Abstract
An understanding of left ventricle (LV) mechanics is fundamental for designing better preventive, diagnostic, and treatment strategies for improved heart function. Because of the costs of clinical and experimental studies to treat and understand heart function, respectively, in-silico models play an important role. Finite element (FE) models, which have been used to create in-silico LV models for different cardiac health and disease conditions, as well as cardiac device design, are time-consuming and require powerful computational resources, which limits their use when real-time results are needed. As an alternative, we sought to use deep learning (DL) for LV in-silico modeling. We used 80 four-chamber heart FE models for feed forward, as well as recurrent neural network (RNN) with long short-term memory (LSTM) models for LV pressure and volume. We used 120 LV-only FE models for training LV stress predictions. The active material properties of the myocardium and time were features for the LV pressure and volume training, and passive material properties and element centroid coordinates were features of the LV stress prediction models. For six test FE models, the DL error for LV volume was 1.599 ± 1.227 ml, and the error for pressure was 1.257 ± 0.488 mmHg; for 20 LV FE test examples, the mean absolute errors were, respectively, 0.179 ± 0.050 for myofiber, 0.049 ± 0.017 for cross-fiber, and 0.039 ± 0.011 kPa for shear stress. After training, the DL runtime was in the order of seconds whereas equivalent FE runtime was in the order of several hours (pressure and volume) or 20 min (stress). We conclude that using DL, LV in-silico simulations can be provided for applications requiring real-time results.
Collapse
Affiliation(s)
- Yaghoub Dabiri
- 3DT Holdings LLC, San Diego, CA, USA
- California Medical Innovations Institute, 11107 Roselle, San Diego, CA, 92121, USA
| | | | - Kevin L Sack
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Jenny S Choy
- California Medical Innovations Institute, 11107 Roselle, San Diego, CA, 92121, USA
| | - Julius M Guccione
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Ghassan S Kassab
- California Medical Innovations Institute, 11107 Roselle, San Diego, CA, 92121, USA.
| |
Collapse
|
45
|
Wu W, Samant S, de Zwart G, Zhao S, Khan B, Ahmad M, Bologna M, Watanabe Y, Murasato Y, Burzotta F, Brilakis ES, Dangas G, Louvard Y, Stankovic G, Kassab GS, Migliavacca F, Chiastra C, Chatzizisis YS. 3D reconstruction of coronary artery bifurcations from coronary angiography and optical coherence tomography: feasibility, validation, and reproducibility. Sci Rep 2020; 10:18049. [PMID: 33093499 PMCID: PMC7582159 DOI: 10.1038/s41598-020-74264-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/10/2020] [Indexed: 11/09/2022] Open
Abstract
The three-dimensional (3D) representation of the bifurcation anatomy and disease burden is essential for better understanding of the anatomical complexity of bifurcation disease and planning of stenting strategies. We propose a novel methodology for 3D reconstruction of coronary artery bifurcations based on the integration of angiography, which provides the backbone of the bifurcation, with optical coherence tomography (OCT), which provides the vessel shape. Our methodology introduces several technical novelties to tackle the OCT frame misalignment, correct positioning of the OCT frames at the carina, lumen surface reconstruction, and merging of bifurcation lumens. The accuracy and reproducibility of the methodology were tested in n = 5 patient-specific silicone bifurcations compared to contrast-enhanced micro-computed tomography (µCT), which was used as reference. The feasibility and time-efficiency of the method were explored in n = 7 diseased patient bifurcations of varying anatomical complexity. The OCT-based reconstructed bifurcation models were found to have remarkably high agreement compared to the µCT reference models, yielding r2 values between 0.91 and 0.98 for the normalized lumen areas, and mean differences of 0.005 for lumen shape and 0.004 degrees for bifurcation angles. Likewise, the reproducibility of our methodology was remarkably high. Our methodology successfully reconstructed all the patient bifurcations yielding favorable processing times (average lumen reconstruction time < 60 min). Overall, our method is an easily applicable, time-efficient, and user-friendly tool that allows accurate and reproducible 3D reconstruction of coronary bifurcations. Our technique can be used in the clinical setting to provide information about the bifurcation anatomy and plaque burden, thereby enabling planning, education, and decision making on bifurcation stenting.
Collapse
Affiliation(s)
- Wei Wu
- Cardiovasclar Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, Omaha, 68105, USA
| | - Saurabhi Samant
- Cardiovasclar Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, Omaha, 68105, USA
| | - Gijs de Zwart
- StudioGijs, Daendelsstraat 40, 5018 ES, Tilburg, The Netherlands
| | - Shijia Zhao
- Cardiovasclar Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, Omaha, 68105, USA
| | - Behram Khan
- Cardiovasclar Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, Omaha, 68105, USA
| | - Mansoor Ahmad
- Cardiovasclar Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, Omaha, 68105, USA
| | - Marco Bologna
- Biosignals, Bioimaging and Bioinformatics Laboratory (B3-Lab), Department of Electronics, Information and Bioengineering, Politecnico di Milano, 20133, Milan, Italy
| | - Yusuke Watanabe
- Department of Cardiology, Teikyo University Hospital, Tokyo, 173-0003, Japan
| | - Yoshinobu Murasato
- Department of Cardiology, National Hospital Organization Kyushu Medical Center, Fukuoka, 810-0065, Japan
| | - Francesco Burzotta
- Department of Cardiovascular Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | | | - George Dangas
- Department of Cardiovascular Medicine, Mount Sinai Hospital, New York City, 10029, USA
| | - Yves Louvard
- Institut Cardiovasculaire Paris Sud, 91300, Massy, France
| | - Goran Stankovic
- Department of Cardiology, Clinical Center of Serbia, 11000, Belgrade, Serbia
| | - Ghassan S Kassab
- California Medical Innovation Institute, San Diego, CA, 92121, USA
| | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta, Politecnico di Milano, 20133, Milan, Italy
| | - Claudio Chiastra
- PoliToBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, 10129, Turin, Italy
| | - Yiannis S Chatzizisis
- Cardiovasclar Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, Omaha, 68105, USA.
| |
Collapse
|
46
|
Fan L, Namani R, Choy JS, Kassab GS, Lee LC. Effects of Mechanical Dyssynchrony on Coronary Flow: Insights From a Computational Model of Coupled Coronary Perfusion With Systemic Circulation. Front Physiol 2020; 11:915. [PMID: 32922304 PMCID: PMC7457036 DOI: 10.3389/fphys.2020.00915] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/08/2020] [Indexed: 01/01/2023] Open
Abstract
Mechanical dyssynchrony affects left ventricular (LV) mechanics and coronary perfusion. Due to the confounding effects of their bi-directional interactions, the mechanisms behind these changes are difficult to isolate from experimental and clinical studies alone. Here, we develop and calibrate a closed-loop computational model that couples the systemic circulation, LV mechanics, and coronary perfusion. The model is applied to simulate the impact of mechanical dyssynchrony on coronary flow in the left anterior descending artery (LAD) and left circumflex artery (LCX) territories caused by regional alterations in perfusion pressure and intramyocardial pressure (IMP). We also investigate the effects of regional coronary flow alterations on regional LV contractility in mechanical dyssynchrony based on prescribed contractility-flow relationships without considering autoregulation. The model predicts that LCX and LAD flows are reduced by 7.2%, and increased by 17.1%, respectively, in mechanical dyssynchrony with a systolic dyssynchrony index of 10% when the LAD's IMP is synchronous with the arterial pressure. The LAD flow is reduced by 11.6% only when its IMP is delayed with respect to the arterial pressure by 0.07 s. When contractility is sensitive to coronary flow, mechanical dyssynchrony can affect global LV mechanics, IMPs and contractility that in turn, further affect the coronary flow in a feedback loop that results in a substantial reduction of dPLV/dt, indicative of ischemia. Taken together, these findings imply that regional IMPs play a significant role in affecting regional coronary flows in mechanical dyssynchrony and the changes in regional coronary flow may produce ischemia when contractility is sensitive to the changes in coronary flow.
Collapse
Affiliation(s)
- Lei Fan
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| | - Ravi Namani
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| | - Jenny S Choy
- California Medical Innovation Institute, San Diego, CA, United States
| | - Ghassan S Kassab
- California Medical Innovation Institute, San Diego, CA, United States
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| |
Collapse
|
47
|
Zhang JM, Chandola G, Tan RS, Chai P, Teo LLS, Low R, Allen JC, Huang W, Fam JM, Chin CY, Wong ASL, Low AF, Kassab GS, Chua T, Tan SY, Lim ST, Zhong L. Quantification of effects of mean blood pressure and left ventricular mass on noninvasive fast fractional flow reserve. Am J Physiol Heart Circ Physiol 2020; 319:H360-H369. [DOI: 10.1152/ajpheart.00135.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
While brachial mean blood pressure (MBP) and left ventricular mass (LVM) measured from CTCA are the two CFD simulation input parameters, their effects on noninvasive fractional flow reserve (FFRB) have not been systematically investigated. We demonstrate that inaccurate MBP and LVM inputs differing from patient-specific values could result in misclassification of borderline ischemic lesions. This is important in the clinical application of noninvasive FFR in coronary artery disease diagnosis.
Collapse
Affiliation(s)
- Jun-Mei Zhang
- National Heart Centre Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | | | - Ru-San Tan
- National Heart Centre Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Ping Chai
- National University Hospital, Singapore
| | | | - Ris Low
- National Heart Centre Singapore, Singapore
| | - John Carson Allen
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Weimin Huang
- Institute for Infocomm Research, Agency for Science, Technology and Research, Singapore
| | | | | | - Aaron Sung Lung Wong
- National Heart Centre Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | | | | | - Terrance Chua
- National Heart Centre Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Swee Yaw Tan
- National Heart Centre Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Soo Teik Lim
- National Heart Centre Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Liang Zhong
- National Heart Centre Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| |
Collapse
|
48
|
Sack KL, Aliotta E, Choy JS, Ennis DB, Davies NH, Franz T, Kassab GS, Guccione JM. Intra-myocardial alginate hydrogel injection acts as a left ventricular mid-wall constraint in swine. Acta Biomater 2020; 111:170-180. [PMID: 32428678 PMCID: PMC7368390 DOI: 10.1016/j.actbio.2020.04.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 04/09/2020] [Accepted: 04/20/2020] [Indexed: 02/07/2023]
Abstract
Despite positive initial outcomes emerging from preclinical and early clinical investigation of alginate hydrogel injection therapy as a treatment for heart failure, the lack of knowledge about the mechanism of action remains a major shortcoming that limits the efficacy of treatment design. To identify the mechanism of action, we examined previously unobtainable measurements of cardiac function from in vivo, ex vivo, and in silico states of clinically relevant heart failure (HF) in large animals. High-resolution ex vivo magnetic resonance imaging and histological data were used along with state-of-the-art subject-specific computational model simulations. Ex vivo data were incorporated in detailed geometric computational models for swine hearts in health (n = 5), ischemic HF (n = 5), and ischemic HF treated with alginate hydrogel injection therapy (n = 5). Hydrogel injection therapy mitigated elongation of sarcomere lengths (1.68 ± 0.10μm [treated] vs. 1.78 ± 0.15μm [untreated], p<0.001). Systolic contractility in treated animals improved substantially (ejection fraction = 43.9 ± 2.8% [treated] vs. 34.7 ± 2.7% [untreated], p<0.01). The in silico models realistically simulated in vivo function with >99% accuracy and predicted small myofiber strain in the vicinity of the solidified hydrogel that was sustained for up to 13 mm away from the implant. These findings suggest that the solidified alginate hydrogel material acts as an LV mid-wall constraint that significantly reduces adverse LV remodeling compared to untreated HF controls without causing negative secondary outcomes to cardiac function. STATEMENT OF SIGNIFICANCE: Heart failure is considered a growing epidemic and hence an important health problem in the US and worldwide. Its high prevalence (5.8 million and 23 million, respectively) is expected to increase by 25% in the US alone by 2030. Heart failure is associated with high morbidity and mortality, has a 5-year mortality rate of 50%, and contributes considerably to the overall cost of health care ($53.1 billion in the US by 2030). Despite positive initial outcomes emerging from preclinical and early clinical investigation of alginate hydrogel injection therapy as a treatment for heart failure, the lack of knowledge concerning the mechanism of action remains a major shortcoming that limits the efficacy of treatment design. To understand the mechanism of action, we combined high-resolution ex vivo magnetic resonance imaging and histological data in swine with state-of-the-art subject-specific computational model simulations. The in silico models realistically simulated in vivo function with >99% accuracy and predicted small myofiber strain in the vicinity of the solidified hydrogel that was sustained for up to 13 mm away from the implant. These findings suggest that the solidified alginate hydrogel material acts as a left ventricular mid-wall constraint that significantly reduces adverse LV remodeling compared to untreated heart failure controls without causing negative secondary outcomes to cardiac function. Moreover, if the hydrogel can be delivered percutaneously rather than via the currently used open-chest procedure, this therapy may become routine for heart failure treatment. A minimally invasive procedure would be in the best interest of this patient population; i.e., one that cannot tolerate general anesthesia and surgery, and it would be significantly more cost-effective than surgery.
Collapse
Affiliation(s)
- Kevin L Sack
- Division of Adult Cardiothoracic Surgery, Department of Surgery, University of California at San Francisco, Box 0118, UC Hall Room U-158, San Francisco, CA, United States; Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Eric Aliotta
- Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Jenny S Choy
- California Medical Innovations Institute, Inc., San Diego, California, USA
| | - Daniel B Ennis
- Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Neil H Davies
- Cardiovascular Research Unit, Department of Surgery, University of Cape Town, Cape Town, South Africa
| | - Thomas Franz
- Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Cape Town, South Africa; Bioengineering Science Research Group, Engineering Sciences, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - Ghassan S Kassab
- California Medical Innovations Institute, Inc., San Diego, California, USA
| | - Julius M Guccione
- Division of Adult Cardiothoracic Surgery, Department of Surgery, University of California at San Francisco, Box 0118, UC Hall Room U-158, San Francisco, CA, United States.
| |
Collapse
|
49
|
Guo X, Kassab GS. Increased Serum Klotho With Age-Related Aortic Stiffness and Peripheral Vascular Resistance in Young and Middle-Aged Swine. Front Physiol 2020; 11:591. [PMID: 32581850 PMCID: PMC7297143 DOI: 10.3389/fphys.2020.00591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/11/2020] [Indexed: 12/20/2022] Open
Abstract
The anti-aging function of Klotho gene has been implicated in age-related diseases. The physiological importance of Klotho in the progression of arterial stiffness with aging, however, remains unclear. The goal of this study is to determine the correlation of circulating Klotho with early age-related aortic stiffening and peripheral hemodynamics. We measured serum Klotho levels in a group of pigs with age ranges of 1.5-9 years and investigated the relationship between Klotho levels and biomarkers of aortic stiffening with aging, including aortic pulse wave velocity (PWV), augmentation index (AIx), and pulse pressure (PP). The effects of aortic stiffening on peripheral vascular resistance, compliance, and function were also evaluated. We found that increased aortic stiffness occurred at middle age (>5 years old), as evidenced by an increase in PWV and AIx (p < 0.001), but with no changes in blood pressure and PP. With advancing age, increased femoral vascular resistance positively correlated with aortic PWV and AIx (p < 0.01). No significant difference in endothelium function and arterial compliance for femoral and small peripheral arteries was observed between young and middle-aged groups. The serum Klotho levels were lower in young and higher in middle-aged pigs (p < 0.001), and a positive correlation was found between Klotho and aortic PWV, AIx, and femoral vascular resistance (p < 0.01). Our findings suggest that early-aged aortic stiffening has adverse effect on peripheral hemodynamics, independent of blood pressure levels. Elevated Klotho secretion was associated with increased aortic stiffness and peripheral vascular resistance with aging.
Collapse
Affiliation(s)
| | - Ghassan S. Kassab
- California Medical Innovations Institute, San Diego, CA, United States
| |
Collapse
|
50
|
Labarrere CA, Hardin JW, Jaeger BR, Bhatt DL, Kassab GS. IgM Antibodies with atheroprotective properties in heart transplants are IgM anti‐phosphorylcholine. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.04989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Deepak L. Bhatt
- Brigham and Women’s Hospital Heart and Vascular Center Harvard Medical School
| | | |
Collapse
|