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Bennati L, Puppini G, Giambruno V, Luciani GB, Vergara C. Image-Based Computational Fluid Dynamics to Compare Two Repair Techniques for Mitral Valve Prolapse. Ann Biomed Eng 2024:10.1007/s10439-024-03597-8. [PMID: 39120769 DOI: 10.1007/s10439-024-03597-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 07/29/2024] [Indexed: 08/10/2024]
Abstract
OBJECTIVE : The treatment of mitral valve prolapse involves two distinct repair techniques: chordal replacement (Neochordae technique) and leaflet resection (Resection technique). However, there is still a debate in the literature about which is the optimal one. In this context, we performed an image-based computational fluid dynamic study to evaluate blood dynamics in the two surgical techniques. METHODS : We considered a healthy subject (H) and two patients (N and R) who underwent surgery for prolapse of the posterior leaflet and were operated with the Neochordae and Resection technique, respectively. Computational Fluid Dynamics (CFD) was employed with prescribed motion of the entire left heart coming from cine-MRI images, with a Large Eddy Simulation model to describe the transition to turbulence and a resistive method for managing valve dynamics. We created three different virtual scenarios where the operated mitral valves were inserted in the same left heart geometry of the healthy subject to study the differences attributed only to the two techniques. RESULTS : We compared the three scenarios by quantitatively analyzing ventricular velocity patterns and pressures, transition to turbulence, and the ventricle ability to prevent thrombi formation. From these results, we found that the operative techniques affected the ventricular blood dynamics in different ways, with variations attributed to the reduced mobility of the Resection posterior leaflet. Specifically, the Resection technique resulted in turbulent forces, related with the risk of hemolysis formation, up to 640 Pa, while the other two scenarios exhibited a maximum of 240 Pa. Moreover, in correspondence of the ventricular apex, the Resection technique reduced the areas with low velocity to 15%, whereas the healthy case and the Neochordae case maintained these areas at 30 and 48%, respectively. Our findings suggest that the Neochordae technique developed a more physiological flow with respect to the Resection technique. CONCLUSION: Resection technique gives rise to a different direction of the mitral jet during diastole increasing the ability to washout the ventricular apex preventing from thrombi formation, but at the same time it promotes turbulence formation that is associated with ventricular effort and risk of hemolysis.
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Affiliation(s)
- Lorenzo Bennati
- Department of Surgery, Dentistry, Pediatrics, and Obstetrics/Gynecology, University of Verona, Piazzale Ludovico Antonio Scuro 10, Verona, 37134, Italy
| | - Giovanni Puppini
- Department of Radiology, University of Verona, Piazzale Stefani 1, Verona, 37126, Italy
| | - Vincenzo Giambruno
- Division of Cardiac Surgery, Department of Surgery, Dentistry, Pediatrics, and Obstetrics/Gynecology, University of Verona, Piazzale Stefani 1, Verona, 37126, Italy
| | - Giovanni Battista Luciani
- Division of Cardiac Surgery, Department of Surgery, Dentistry, Pediatrics, and Obstetrics/Gynecology, University of Verona, Piazzale Stefani 1, Verona, 37126, Italy
| | - Christian Vergara
- LaBS, Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan, 20133, Italy.
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Rodríguez-Aparicio S, Ferrera C, Millán-Núñez MV, García García J, Dueñas-Pamplona J. Influence of the flow split ratio on the position of the main atrial vortex: Implications for stasis on the left atrial appendage. Comput Biol Med 2024; 178:108772. [PMID: 38917532 DOI: 10.1016/j.compbiomed.2024.108772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/17/2024] [Accepted: 06/15/2024] [Indexed: 06/27/2024]
Abstract
BACKGROUND Despite the recent advances in computational fluid dynamics (CFD) techniques applied to blood flow within the left atrium (LA), the relationship between atrial geometry, flow patterns, and blood stasis within the left atrial appendage (LAA) remains unclear. A better understanding of this relationship would have important clinical implications, as thrombi originating in the LAA are a common cause of stroke in patients with atrial fibrillation (AF). AIM To identify the most representative atrial flow patterns on a patient-specific basis and study their influence on LAA blood stasis by varying the flow split ratio and some common atrial modeling assumptions. METHODS Three recent techniques were applied to nine patient-specific computational fluid dynamics (CFD) models of patients with AF: a kinematic atrial model to isolate the influence of wall motion because of AF, projection on a universal LAA coordinate system, and quantification of stagnant blood volume (SBV). RESULTS We identified three different atrial flow patterns based on the position of the center of the main circulatory flow. The results also illustrate how atrial flow patterns are highly affected by the flow split ratio, increasing the SBV within the LAA. As the flow split ratio is determined by the patient's lying position, the results suggest that the most frequent position adopted while sleeping may have implications for the medium- and long-term risks of stroke.
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Affiliation(s)
- Sergio Rodríguez-Aparicio
- Departamento de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, Avda. Elvas s/n, Badajoz 06006, Spain
| | - Conrado Ferrera
- Departamento de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, Avda. Elvas s/n, Badajoz 06006, Spain; Instituto de Computación Científica Avanzada (ICCAEX), Avda. Elvas s/n, Badajoz 06006, Spain
| | | | - Javier García García
- Departamento de Ingeniería Energética, Universidad Politécnica de Madrid, Avda. de Ramiro de Maeztu 7, Madrid 28040, Spain
| | - Jorge Dueñas-Pamplona
- Departamento de Ingeniería Energética, Universidad Politécnica de Madrid, Avda. de Ramiro de Maeztu 7, Madrid 28040, Spain.
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Catalano C, Crascì F, Puleo S, Scuoppo R, Pasta S, Raffa GM. Computational fluid dynamics in cardiac surgery and perfusion: A review. Perfusion 2024:2676591241239277. [PMID: 38850015 DOI: 10.1177/02676591241239277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
Cardiovascular diseases persist as a leading cause of mortality and morbidity, despite significant advances in diagnostic and surgical approaches. Computational Fluid Dynamics (CFD) represents a branch of fluid mechanics widely used in industrial engineering but is increasingly applied to the cardiovascular system. This review delves into the transformative potential for simulating cardiac surgery procedures and perfusion systems, providing an in-depth examination of the state-of-the-art in cardiovascular CFD modeling. The study first describes the rationale for CFD modeling and later focuses on the latest advances in heart valve surgery, transcatheter heart valve replacement, aortic aneurysms, and extracorporeal membrane oxygenation. The review underscores the role of CFD in better understanding physiopathology and its clinical relevance, as well as the profound impact of hemodynamic stimuli on patient outcomes. By integrating computational methods with advanced imaging techniques, CFD establishes a quantitative framework for understanding the intricacies of the cardiac field, providing valuable insights into disease progression and treatment strategies. As technology advances, the evolving synergy between computational simulations and clinical interventions is poised to revolutionize cardiovascular care. This collaboration sets the stage for more personalized and effective therapeutic strategies. With its potential to enhance our understanding of cardiac pathologies, CFD stands as a promising tool for improving patient outcomes in the dynamic landscape of cardiovascular medicine.
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Affiliation(s)
- Chiara Catalano
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
| | - Fabrizio Crascì
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
- Department of Research, IRCCS-ISMETT, Palermo, Italy
| | - Silvia Puleo
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
| | - Roberta Scuoppo
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
| | - Salvatore Pasta
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
- Department of Research, IRCCS-ISMETT, Palermo, Italy
| | - Giuseppe M Raffa
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Palermo, Italy
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4
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Kjeldsberg HA, Albors C, Mill J, Medel DV, Camara O, Sundnes J, Valen-Sendstad K. Impact of left atrial wall motion assumptions in fluid simulations on proposed predictors of thrombus formation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3825. [PMID: 38629309 DOI: 10.1002/cnm.3825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 02/18/2024] [Accepted: 04/05/2024] [Indexed: 06/11/2024]
Abstract
Atrial fibrillation (AF) poses a significant risk of stroke due to thrombus formation, which primarily occurs in the left atrial appendage (LAA). Medical image-based computational fluid dynamics (CFD) simulations can provide valuable insight into patient-specific hemodynamics and could potentially enhance personalized assessment of thrombus risk. However, the importance of accurately representing the left atrial (LA) wall dynamics has not been fully resolved. In this study, we compared four modeling scenarios; rigid walls, a generic wall motion based on a reference motion, a semi-generic wall motion based on patient-specific motion, and patient-specific wall motion based on medical images. We considered a LA geometry acquired from 4D computed tomography during AF, systematically performed convergence tests to assess the numerical accuracy of our solution strategy, and quantified the differences between the four approaches. The results revealed that wall motion had no discernible impact on LA cavity hemodynamics, nor on the markers that indicate thrombus formation. However, the flow patterns within the LAA deviated significantly in the rigid model, indicating that the assumption of rigid walls may lead to errors in the estimated risk factors. In contrast, the generic, semi-generic, and patient-specific cases were qualitatively similar. The results highlight the crucial role of wall motion on hemodynamics and predictors of thrombus formation, and also demonstrate the potential of using a generic motion model as a surrogate for the more complex patient-specific motion. While the present study considered a single case, the employed CFD framework is entirely open-source and designed for adaptability, allowing for integration of additional models and generic motions.
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Affiliation(s)
- Henrik A Kjeldsberg
- Department of Computational Physiology, Simula Research Laboratory, Oslo, Norway
| | - Carlos Albors
- Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Jordi Mill
- Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | | | - Oscar Camara
- Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Joakim Sundnes
- Department of Computational Physiology, Simula Research Laboratory, Oslo, Norway
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5
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Zingaro A, Ahmad Z, Kholmovski E, Sakata K, Dede' L, Morris AK, Quarteroni A, Trayanova NA. A comprehensive stroke risk assessment by combining atrial computational fluid dynamics simulations and functional patient data. Sci Rep 2024; 14:9515. [PMID: 38664464 PMCID: PMC11045804 DOI: 10.1038/s41598-024-59997-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Stroke, a major global health concern often rooted in cardiac dynamics, demands precise risk evaluation for targeted intervention. Current risk models, like theCHA 2 DS 2 -VASc score, often lack the granularity required for personalized predictions. In this study, we present a nuanced and thorough stroke risk assessment by integrating functional insights from cardiac magnetic resonance (CMR) with patient-specific computational fluid dynamics (CFD) simulations. Our cohort, evenly split between control and stroke groups, comprises eight patients. Utilizing CINE CMR, we compute kinematic features, revealing smaller left atrial volumes for stroke patients. The incorporation of patient-specific atrial displacement into our hemodynamic simulations unveils the influence of atrial compliance on the flow fields, emphasizing the importance of LA motion in CFD simulations and challenging the conventional rigid wall assumption in hemodynamics models. Standardizing hemodynamic features with functional metrics enhances the differentiation between stroke and control cases. While standalone assessments provide limited clarity, the synergistic fusion of CMR-derived functional data and patient-informed CFD simulations offers a personalized and mechanistic understanding, distinctly segregating stroke from control cases. Specifically, our investigation reveals a crucial clinical insight: normalizing hemodynamic features based on ejection fraction fails to differentiate between stroke and control patients. Differently, when normalized with stroke volume, a clear and clinically significant distinction emerges and this holds true for both the left atrium and its appendage, providing valuable implications for precise stroke risk assessment in clinical settings. This work introduces a novel framework for seamlessly integrating hemodynamic and functional metrics, laying the groundwork for improved predictive models, and highlighting the significance of motion-informed, personalized risk assessments.
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Affiliation(s)
- Alberto Zingaro
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD, 21218, USA.
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
- ELEM Biotech S.L., Pier07, Via Laietana, 26, 08003, Barcelona, Spain.
| | - Zan Ahmad
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD, 21218, USA
- Department of Applied Mathematics and Statistics, Johns Hopkins University, 100 Wyman Park Dr, Baltimore, MD, 21211, USA
| | - Eugene Kholmovski
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD, 21218, USA
- Department of Radiology, University of Utah, 30 N Mario Capecchi Dr., Salt Lake City, UT, 84112, USA
| | - Kensuke Sakata
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD, 21218, USA
| | - Luca Dede'
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - Alan K Morris
- Scientific Computing and Imaging Institute, University of Utah, 72 Central Campus Dr., Salt Lake City, UT, 84112, USA
| | - Alfio Quarteroni
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
- Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Station 8, Av. Piccard, 1015, Lausanne, Switzerland
| | - Natalia A Trayanova
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD, 21218, USA
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Khalili E, Daversin-Catty C, Olivares AL, Mill J, Camara O, Valen-Sendstad K. On the importance of fundamental computational fluid dynamics toward a robust and reliable model of left atrial flows. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3804. [PMID: 38286150 DOI: 10.1002/cnm.3804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 08/31/2023] [Accepted: 01/07/2024] [Indexed: 01/31/2024]
Abstract
Computational fluid dynamics (CFD) studies of left atrial flows have reached a sophisticated level, for example, revealing plausible relationships between hemodynamics and stresses with atrial fibrillation. However, little focus has been on fundamental fluid modeling of LA flows. The purpose of this study was to investigate the spatiotemporal convergence, along with the differences between high- (HR) versus normal-resolution/accuracy (NR) solution strategies, respectively. Rigid wall CFD simulations were conducted on 12 patient-specific left atrial geometries obtained from computed tomography scans, utilizing a second-order accurate and space/time-centered solver. The convergence studies showed an average variability of around 30% and 55% for time averaged wall shear stress (WSS), oscillatory shear index (OSI), relative residence time (RRT), and endothelial cell activation potential (ECAP), even between intermediate spatial and temporal resolutions, in the left atrium (LA) and left atrial appendage (LAA), respectively. The comparison between HR and NR simulations showed good correlation in the LA for WSS, RRT, and ECAP (R 2 > .9 ), but not for OSI (R 2 = .63 ). However, there were poor correlations in the LAA especially for OSI, RRT, and ECAP (R 2 = .55, .63, and .61, respectively), except for WSS (R 2 = .81 ). The errors are comparable to differences previously reported with disease correlations. To robustly predict atrial hemodynamics and stresses, numerical resolutions of 10 M elements (i.e., Δ x = ∼ .5 mm) and 10 k time-steps per cycle seem necessary (i.e., one order of magnitude higher than normally used in both space and time). In conclusion, attention to fundamental numerical aspects is essential toward establishing a plausible, robust, and reliable model of LA flows.
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Affiliation(s)
- Ehsan Khalili
- Department of Computational Physiology, Simula Research Laboratory, Oslo, Norway
| | - Cécile Daversin-Catty
- Department of Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
| | - Andy L Olivares
- Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Jordi Mill
- Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Oscar Camara
- Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
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7
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Ge L, Xu Y, Li J, Li Y, Xi Y, Wang X, Wang J, Mu Y, Wang H, Lu X, Guo J, Chen Z, Chen T, Chen Y. The impact of contrast retention on thrombus formation risks in patients with atrial fibrillation: A numerical study. Heliyon 2024; 10:e26792. [PMID: 38434273 PMCID: PMC10907767 DOI: 10.1016/j.heliyon.2024.e26792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 02/20/2024] [Indexed: 03/05/2024] Open
Abstract
Background Contrast retention (CR) is an important predictor of left atrial appendage thrombus (LAAT) and stroke in patients with non-valvular atrial fibrillation (AF). We sought to explore the underlying mechanisms of CR using computational fluid dynamic (CFD) simulations. Methods A total of 12 patients with AF who underwent both cardiac computed tomography angiography (CTA) and transesophageal echocardiography (TEE) before left atrial appendage occlusion (LAAO) were included in the study. The patients were allocated into the CR group or non-CR group based on left atrial appendage (LAA) angiography. Patient-specific models were reconstructed to evaluate time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and endothelial cell activation potential (ECAP). Additionally, the incidence of thrombosis was predicted using residence time (RT) at different time-points. Results TAWSS was lower [median (Interquartile Range) 0.27 (0.19-0.47) vs 1.35 (0.92-1.79), p < 0.001] in LAA compared to left atrium. In contrast, RRT [1438 (409.70-13869) vs 2.23 (1.81-3.14), p < 0.001] and ECAP [122.70 (30.01-625.70) vs 0.19 (0.16-0.27), p < 0.001)] was higher in the LAA. The patients in the CR group had significantly higher RRT [(mean ± SD) 16274 ± 11797 vs 639.70 ± 595.20, p = 0.009] and ECAP [610.80 ± 365.30 vs 54.26 ± 54.38, p = 0.004] in the LAA compared to the non-CR group. Additionally, patients with CR had a wider range of thrombus-prone regions [0.44(0.27-0.66)% vs 0.05(0.03-0.27)%, p = 0.009] at the end of the 15th cardiac cycle. Conclusions These findings suggest that CR might be an indicator of high-risk thrombus formation in the LAA. And CT-based CFD simulation may be a feasible substitute for the evaluation of LAA thrombotic risk in patients with AF, especially in patients with CR.
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Affiliation(s)
- Lan Ge
- Medical School of Chinese PLA, 28 Fuxing Road, Haidian District, Beijing 100853, China
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Yawei Xu
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Jun Li
- Medical School of Chinese PLA, 28 Fuxing Road, Haidian District, Beijing 100853, China
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Yuan Li
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Yifeng Xi
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Xinyan Wang
- Medical School of Chinese PLA, 28 Fuxing Road, Haidian District, Beijing 100853, China
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Jing Wang
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Yang Mu
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Hongsen Wang
- Medical School of Chinese PLA, 28 Fuxing Road, Haidian District, Beijing 100853, China
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Xu Lu
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Jun Guo
- Medical School of Chinese PLA, 28 Fuxing Road, Haidian District, Beijing 100853, China
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Zengsheng Chen
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Tao Chen
- Medical School of Chinese PLA, 28 Fuxing Road, Haidian District, Beijing 100853, China
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
| | - Yundai Chen
- Medical School of Chinese PLA, 28 Fuxing Road, Haidian District, Beijing 100853, China
- Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China
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Mill J, Harrison J, Saiz-Vivo M, Albors C, Morales X, Olivares AL, Iriart X, Cochet H, Noailly J, Sermesant M, Camara O. The role of the pulmonary veins on left atrial flow patterns and thrombus formation. Sci Rep 2024; 14:5860. [PMID: 38467726 DOI: 10.1038/s41598-024-56658-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 03/08/2024] [Indexed: 03/13/2024] Open
Abstract
Atrial fibrillation (AF) is the most common human arrhythmia, forming thrombi mostly in the left atrial appendage (LAA). However, the relation between LAA morphology, blood patterns and clot formation is not yet fully understood. Furthermore, the impact of anatomical structures like the pulmonary veins (PVs) have not been thoroughly studied due to data acquisition difficulties. In-silico studies with flow simulations provide a detailed analysis of blood flow patterns under different boundary conditions, but a limited number of cases have been reported in the literature. To address these gaps, we investigated the influence of PVs on LA blood flow patterns and thrombus formation risk through computational fluid dynamics simulations conducted on a sizeable cohort of 130 patients, establishing the largest cohort of patient-specific LA fluid simulations reported to date. The investigation encompassed an in-depth analysis of several parameters, including pulmonary vein orientation (e.g., angles) and configuration (e.g., number), LAA and LA volumes as well as their ratio, flow, and mass-less particles. Our findings highlight the total number of particles within the LAA as a key parameter for distinguishing between the thrombus and non-thrombus groups. Moreover, the angles between the different PVs play an important role to determine the flow going inside the LAA and consequently the risk of thrombus formation. The alignment between the LAA and the main direction of the left superior pulmonary vein, or the position of the right pulmonary vein when it exhibits greater inclination, had an impact to distinguish the control group vs. the thrombus group. These insights shed light on the intricate relationship between PV configuration, LAA morphology, and thrombus formation, underscoring the importance of comprehensive blood flow pattern analyses.
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Affiliation(s)
- Jordi Mill
- Physense, BCN Medtech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain.
| | - Josquin Harrison
- Inria, Université Côte d'Azur, Epione team, 06902, Sophia Antipolis, France
| | - Marta Saiz-Vivo
- Physense, BCN Medtech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
| | - Carlos Albors
- Physense, BCN Medtech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
| | - Xabier Morales
- Physense, BCN Medtech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
| | - Andy L Olivares
- Physense, BCN Medtech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
| | - Xavier Iriart
- IHU Liryc, CHU Bordeaux, Université Bordeaux, Inserm, 33600, Pessac, France
- Bordeaux University Hospital, 33600, Bordeaux, France
| | - Hubert Cochet
- IHU Liryc, CHU Bordeaux, Université Bordeaux, Inserm, 33600, Pessac, France
- Bordeaux University Hospital, 33600, Bordeaux, France
| | - Jerome Noailly
- Physense, BCN Medtech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
| | - Maxime Sermesant
- Inria, Université Côte d'Azur, Epione team, 06902, Sophia Antipolis, France
| | - Oscar Camara
- Physense, BCN Medtech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018, Barcelona, Spain
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9
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Zingaro A, Ahmad Z, Kholmovski E, Sakata K, Dede’ L, Morris AK, Quarteroni A, Trayanova NA. A comprehensive stroke risk assessment by combining atrial computational fluid dynamics simulations and functional patient data. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.11.575156. [PMID: 38293150 PMCID: PMC10827064 DOI: 10.1101/2024.01.11.575156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Stroke, a major global health concern often rooted in cardiac dynamics, demands precise risk evaluation for targeted intervention. Current risk models, like the CHA2DS2-VASc score, often lack the granularity required for personalized predictions. In this study, we present a nuanced and thorough stroke risk assessment by integrating functional insights from cardiac magnetic resonance (CMR) with patient-specific computational fluid dynamics (CFD) simulations. Our cohort, evenly split between control and stroke groups, comprises eight patients. Utilizing CINE CMR, we compute kinematic features, revealing smaller left atrial volumes for stroke patients. The incorporation of patient-specific atrial displacement into our hemodynamic simulations unveils the influence of atrial compliance on the flow fields, emphasizing the importance of LA motion in CFD simulations and challenging the conventional rigid wall assumption in hemodynamics models. Standardizing hemodynamic features with functional metrics enhances the differentiation between stroke and control cases. While standalone assessments provide limited clarity, the synergistic fusion of CMR-derived functional data and patient-informed CFD simulations offers a personalized and mechanistic understanding, distinctly segregating stroke from control cases. Specifically, our investigation reveals a crucial clinical insight: normalizing hemodynamic features based on ejection fraction fails to differentiate between stroke and control patients. Differently, when normalized with stroke volume, a clear and clinically significant distinction emerges and this holds true for both the left atrium and its appendage, providing valuable implications for precise stroke risk assessment in clinical settings. This work introduces a novel framework for seamlessly integrating hemodynamic and functional metrics, laying the groundwork for improved predictive models, and highlighting the significance of motion-informed, personalized risk assessments.
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Affiliation(s)
- Alberto Zingaro
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., 21218, Baltimore, MD, USA
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
- ELEM Biotech S.L., Pier07, Via Laietana, 26, 08003, Barcelona, Spain
| | - Zan Ahmad
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., 21218, Baltimore, MD, USA
- Department of Applied Mathematics and Statistics, Johns Hopkins University, 100 Wyman Park Dr, 21211, Baltimore, MD, USA
| | - Eugene Kholmovski
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., 21218, Baltimore, MD, USA
- Department of Radiology, University of Utah, 30 N Mario Capecchi Dr., 84112, Salt Lake City, UT, USA
| | - Kensuke Sakata
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., 21218, Baltimore, MD, USA
| | - Luca Dede’
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | - Alan K. Morris
- Scientific Computing and Imaging Institute, University of Utah, 72 Central Campus Dr., 84112, Salt Lake City, UT, USA
| | - Alfio Quarteroni
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
- Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Station 8, Av. Piccard, CH-1015 Lausanne, Switzerland (Professor Emeritus)
| | - Natalia A. Trayanova
- ADVANCE, Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, 3400 N. Charles St., 21218, Baltimore, MD, USA
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10
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Zingaro A, Bucelli M, Fumagalli I, Dede' L, Quarteroni A. Modeling isovolumetric phases in cardiac flows by an Augmented Resistive Immersed Implicit Surface method. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3767. [PMID: 37615375 DOI: 10.1002/cnm.3767] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 06/05/2023] [Accepted: 07/30/2023] [Indexed: 08/25/2023]
Abstract
A major challenge in the computational fluid dynamics modeling of the heart function is the simulation of isovolumetric phases when the hemodynamics problem is driven by a prescribed boundary displacement. During such phases, both atrioventricular and semilunar valves are closed: consequently, the ventricular pressure may not be uniquely defined, and spurious oscillations may arise in numerical simulations. These oscillations can strongly affect valve dynamics models driven by the blood flow, making unlikely to recovering physiological dynamics. Hence, prescribed opening and closing times are usually employed, or the isovolumetric phases are neglected altogether. In this article, we propose a suitable modification of the Resistive Immersed Implicit Surface (RIIS) method (Fedele et al., Biomech Model Mechanobiol 2017, 16, 1779-1803) by introducing a reaction term to correctly capture the pressure transients during isovolumetric phases. The method, that we call Augmented RIIS (ARIIS) method, extends the previously proposed ARIS method (This et al., Int J Numer Methods Biomed Eng 2020, 36, e3223) to the case of a mesh which is not body-fitted to the valves. We test the proposed method on two different benchmark problems, including a new simplified problem that retains all the characteristics of a heart cycle. We apply the ARIIS method to a fluid dynamics simulation of a realistic left heart geometry, and we show that ARIIS allows to correctly simulate isovolumetric phases, differently from standard RIIS method. Finally, we demonstrate that by the new method the cardiac valves can open and close without prescribing any opening/closing times.
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Affiliation(s)
- Alberto Zingaro
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
- ELEM Biotech S.L., Barcelona, Spain
| | - Michele Bucelli
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | - Ivan Fumagalli
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | - Luca Dede'
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | - Alfio Quarteroni
- MOX, Laboratory of Modeling and Scientific Computing, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
- Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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11
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Africa PC, Piersanti R, Regazzoni F, Bucelli M, Salvador M, Fedele M, Pagani S, Dede' L, Quarteroni A. lifex-ep: a robust and efficient software for cardiac electrophysiology simulations. BMC Bioinformatics 2023; 24:389. [PMID: 37828428 PMCID: PMC10571323 DOI: 10.1186/s12859-023-05513-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 10/02/2023] [Indexed: 10/14/2023] Open
Abstract
BACKGROUND Simulating the cardiac function requires the numerical solution of multi-physics and multi-scale mathematical models. This underscores the need for streamlined, accurate, and high-performance computational tools. Despite the dedicated endeavors of various research teams, comprehensive and user-friendly software programs for cardiac simulations, capable of accurately replicating both normal and pathological conditions, are still in the process of achieving full maturity within the scientific community. RESULTS This work introduces [Formula: see text]-ep, a publicly available software for numerical simulations of the electrophysiology activity of the cardiac muscle, under both normal and pathological conditions. [Formula: see text]-ep employs the monodomain equation to model the heart's electrical activity. It incorporates both phenomenological and second-generation ionic models. These models are discretized using the Finite Element method on tetrahedral or hexahedral meshes. Additionally, [Formula: see text]-ep integrates the generation of myocardial fibers based on Laplace-Dirichlet Rule-Based Methods, previously released in Africa et al., 2023, within [Formula: see text]-fiber. As an alternative, users can also choose to import myofibers from a file. This paper provides a concise overview of the mathematical models and numerical methods underlying [Formula: see text]-ep, along with comprehensive implementation details and instructions for users. [Formula: see text]-ep features exceptional parallel speedup, scaling efficiently when using up to thousands of cores, and its implementation has been verified against an established benchmark problem for computational electrophysiology. We showcase the key features of [Formula: see text]-ep through various idealized and realistic simulations conducted in both normal and pathological scenarios. Furthermore, the software offers a user-friendly and flexible interface, simplifying the setup of simulations using self-documenting parameter files. CONCLUSIONS [Formula: see text]-ep provides easy access to cardiac electrophysiology simulations for a wide user community. It offers a computational tool that integrates models and accurate methods for simulating cardiac electrophysiology within a high-performance framework, while maintaining a user-friendly interface. [Formula: see text]-ep represents a valuable tool for conducting in silico patient-specific simulations.
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Affiliation(s)
- Pasquale Claudio Africa
- MOX, Department of Mathematics, Politecnico di Milano, Milano, Italy
- mathLab, Mathematics Area, SISSA International School for Advanced Studies, Trieste, Italy
| | - Roberto Piersanti
- MOX, Department of Mathematics, Politecnico di Milano, Milano, Italy.
| | | | - Michele Bucelli
- MOX, Department of Mathematics, Politecnico di Milano, Milano, Italy
| | - Matteo Salvador
- MOX, Department of Mathematics, Politecnico di Milano, Milano, Italy
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, California, USA
| | - Marco Fedele
- MOX, Department of Mathematics, Politecnico di Milano, Milano, Italy
| | - Stefano Pagani
- MOX, Department of Mathematics, Politecnico di Milano, Milano, Italy
| | - Luca Dede'
- MOX, Department of Mathematics, Politecnico di Milano, Milano, Italy
| | - Alfio Quarteroni
- MOX, Department of Mathematics, Politecnico di Milano, Milano, Italy
- Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Lausanne, Professor emeritus, Switzerland
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12
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Durán E, García-Villalba M, Martínez-Legazpi P, Gonzalo A, McVeigh E, Kahn AM, Bermejo J, Flores O, Del Álamo JC. Pulmonary vein flow split effects in patient-specific simulations of left atrial flow. Comput Biol Med 2023; 163:107128. [PMID: 37352639 PMCID: PMC10529707 DOI: 10.1016/j.compbiomed.2023.107128] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 05/10/2023] [Accepted: 06/01/2023] [Indexed: 06/25/2023]
Abstract
Disruptions to left atrial (LA) blood flow, such as those caused by atrial fibrillation (AF), can lead to thrombosis in the left atrial appendage (LAA) and an increased risk of systemic embolism. LA hemodynamics are influenced by various factors, including LA anatomy and function, and pulmonary vein (PV) inflow conditions. In particular, the PV flow split can vary significantly among and within patients depending on multiple factors. In this study, we investigated how changes in PV flow split affect LA flow transport, focusing for the first time on blood stasis in the LAA, using a high-fidelity patient-specific computational fluid dynamics (CFD) model. We use an Immersed Boundary Method, simulating the flow in a fixed, uniform Cartesian mesh and imposing the movement of the LA walls with a moving Lagrangian mesh generated from 4D Computerized Tomography images. We analyzed LA anatomies from eight patients with varying atrial function, including three with AF and either a LAA thrombus or a history of Transient Ischemic Attacks (TIAs). Using four different flow splits (60/40% and 55/45% through right and left PVs, even flow rate, and same velocity through each PV), we found that flow patterns are sensitive to PV flow split variations, particularly in planes parallel to the mitral valve. Changes in PV flow split also had a significant impact on blood stasis and could contribute to increased risk for thrombosis inside the LAA, particularly in patients with AF and previous LAA thrombus or a history of TIAs. Our study highlights the importance of considering patient-specific PV flow split variations when assessing LA hemodynamics and identifying patients at increased risk for thrombosis and stroke. This knowledge is relevant to planning clinical procedures such as AF ablation or the implementation of LAA occluders.
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Affiliation(s)
- Eduardo Durán
- Department of Mechanical, Thermal and Fluids Engineering, Universidad de Málaga, Málaga, Spain; Department of Aerospace Engineering, University Carlos III of Madrid, Leganés, Spain.
| | | | - Pablo Martínez-Legazpi
- Department of Mathematical Physics and Fluids, Universidad Nacional de Educación a Distancia, Madrid, Spain
| | - Alejandro Gonzalo
- Department of Mechanical Engineering, University of Washington, Seattle, WA, United States
| | - Elliot McVeigh
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States; Department of Radiology, University of California San Diego, La Jolla, CA, United States
| | - Andrew M Kahn
- Division of Cardiovascular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Javier Bermejo
- Gregorio Marañón University Hospital, Madrid, Spain; Spanish Cardiovascular Network (CIBERCV), Carlos III Health Institute, Madrid, Spain; Faculty of Medicine, Complutense University, Madrid, Spain; Gregorio Marañón Health Research Institute (IISGM), Madrid, Spain
| | - Oscar Flores
- Department of Aerospace Engineering, University Carlos III of Madrid, Leganés, Spain
| | - Juan Carlos Del Álamo
- Department of Mechanical Engineering, University of Washington, Seattle, WA, United States; Center for Cardiovascular Biology, University of Washington, Seattle, WA, United States; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States
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13
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Telle Å, Bargellini C, Chahine Y, Del Álamo JC, Akoum N, Boyle PM. Personalized biomechanical insights in atrial fibrillation: opportunities & challenges. Expert Rev Cardiovasc Ther 2023; 21:817-837. [PMID: 37878350 PMCID: PMC10841537 DOI: 10.1080/14779072.2023.2273896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 10/18/2023] [Indexed: 10/26/2023]
Abstract
INTRODUCTION Atrial fibrillation (AF) is an increasingly prevalent and significant worldwide health problem. Manifested as an irregular atrial electrophysiological activation, it is associated with many serious health complications. AF affects the biomechanical function of the heart as contraction follows the electrical activation, subsequently leading to reduced blood flow. The underlying mechanisms behind AF are not fully understood, but it is known that AF is highly correlated with the presence of atrial fibrosis, and with a manifold increase in risk of stroke. AREAS COVERED In this review, we focus on biomechanical aspects in atrial fibrillation, current and emerging use of clinical images, and personalized computational models. We also discuss how these can be used to provide patient-specific care. EXPERT OPINION Understanding the connection betweenatrial fibrillation and atrial remodeling might lead to valuable understanding of stroke and heart failure pathophysiology. Established and emerging imaging modalities can bring us closer to this understanding, especially with continued advancements in processing accuracy, reproducibility, and clinical relevance of the associated technologies. Computational models of cardiac electromechanics can be used to glean additional insights on the roles of AF and remodeling in heart function.
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Affiliation(s)
- Åshild Telle
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Clarissa Bargellini
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
| | - Yaacoub Chahine
- Division of Cardiology, University of Washington, Seattle, WA, USA
| | - Juan C Del Álamo
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
- Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA
| | - Nazem Akoum
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Division of Cardiology, University of Washington, Seattle, WA, USA
| | - Patrick M Boyle
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
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14
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Viola F, Del Corso G, De Paulis R, Verzicco R. GPU accelerated digital twins of the human heart open new routes for cardiovascular research. Sci Rep 2023; 13:8230. [PMID: 37217483 DOI: 10.1038/s41598-023-34098-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 04/24/2023] [Indexed: 05/24/2023] Open
Abstract
The recruitment of patients for rare or complex cardiovascular diseases is a bottleneck for clinical trials and digital twins of the human heart have recently been proposed as a viable alternative. In this paper we present an unprecedented cardiovascular computer model which, relying on the latest GPU-acceleration technologies, replicates the full multi-physics dynamics of the human heart within a few hours per heartbeat. This opens the way to extensive simulation campaigns to study the response of synthetic cohorts of patients to cardiovascular disorders, novel prosthetic devices or surgical procedures. As a proof-of-concept we show the results obtained for left bundle branch block disorder and the subsequent cardiac resynchronization obtained by pacemaker implantation. The in-silico results closely match those obtained in clinical practice, confirming the reliability of the method. This innovative approach makes possible a systematic use of digital twins in cardiovascular research, thus reducing the need of real patients with their economical and ethical implications. This study is a major step towards in-silico clinical trials in the era of digital medicine.
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Affiliation(s)
- Francesco Viola
- Gran Sasso Science Institute (GSSI), L'Aquila, Italy
- INFN-Laboratori Nazionali del Gran Sasso, Assergi (AQ), Italy
| | - Giulio Del Corso
- Gran Sasso Science Institute (GSSI), L'Aquila, Italy
- Institute of Information Science and Technologies A. Faedo, CNR, Pisa, Italy
| | - Ruggero De Paulis
- European Hospital, Rome, Italy
- UniCamillus International University of Health Sciences, Rome, Italy
| | - Roberto Verzicco
- Gran Sasso Science Institute (GSSI), L'Aquila, Italy.
- University of Rome Tor Vergata, Rome, Italy.
- POF Group, University of Twente, Enschede, The Netherlands.
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15
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Sanatkhani S, Nedios S, Menon PG, Saba SF, Jain SK, Federspiel WJ, Shroff SG. Subject-specific factors affecting particle residence time distribution of left atrial appendage in atrial fibrillation: A computational model-based study. Front Cardiovasc Med 2023; 10:1070498. [PMID: 36993996 PMCID: PMC10040531 DOI: 10.3389/fcvm.2023.1070498] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/20/2023] [Indexed: 03/15/2023] Open
Abstract
BackgroundAtrial fibrillation (AF) is a prevalent arrhythmia, that causes thrombus formation, ordinarily in the left atrial appendage (LAA). The conventional metric of stroke risk stratification, CHA2DS2-VASc score, does not account for LAA morphology or hemodynamics. We showed in our previous study that residence time distribution (RTD) of blood-borne particles in the LAA and its associated calculated variables (i.e., mean residence time, tm, and asymptotic concentration, C∞) have the potential to improve CHA2DS2-VASc score. The purpose of this research was to investigate the effects of the following potential confounding factors on LAA tm and C∞: (1) pulmonary vein flow waveform pulsatility, (2) non-Newtonian blood rheology and hematocrit level, and (3) length of the simulation.MethodsSubject-Specific data including left atrial (LA) and LAA cardiac computed tomography, cardiac output (CO), heart rate, and hematocrit level were gathered from 25 AF subjects. We calculated LAA tm and C∞ based on series of computational fluid dynamics (CFD) analyses.ResultsBoth LAA tm and C∞ are significantly affected by the CO, but not by temporal pattern of the inlet flow. Both LAA tm and C∞ increase with increasing hematocrit level and both calculated indices are higher for non-Newtonian blood rheology for a given hematocrit level. Further, at least 20,000 s of CFD simulation is needed to calculate LAA tm and C∞ values reliably.ConclusionsSubject-specific LA and LAA geometries, CO, and hematocrit level are essential to quantify the subject-specific proclivity of blood cell tarrying inside LAA in terms of the RTD function.
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Affiliation(s)
- Soroosh Sanatkhani
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sotirios Nedios
- Department of Electrophysiology, Massachusetts General Hospital, Boston, MA, United States
- Heart Center, Department of Electrophysiology, University of Leipzig, Leipzig, Germany
- Cardiovascular Research Institute Maastricht (CARIM), Department of Cardiology, Maastricht University Medical Center, Maastricht, Netherlands
| | - Prahlad G. Menon
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Samir F. Saba
- Heart and Vascular Institute, UPMC Presbyterian, Pittsburgh, PA, United States
| | - Sandeep K. Jain
- Heart and Vascular Institute, UPMC Presbyterian, Pittsburgh, PA, United States
| | - William J. Federspiel
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sanjeev G. Shroff
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Correspondence: Sanjeev G. Shroff
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16
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Bucelli M, Zingaro A, Africa PC, Fumagalli I, Dede' L, Quarteroni A. A mathematical model that integrates cardiac electrophysiology, mechanics, and fluid dynamics: Application to the human left heart. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3678. [PMID: 36579792 DOI: 10.1002/cnm.3678] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
We propose a mathematical and numerical model for the simulation of the heart function that couples cardiac electrophysiology, active and passive mechanics and hemodynamics, and includes reduced models for cardiac valves and the circulatory system. Our model accounts for the major feedback effects among the different processes that characterize the heart function, including electro-mechanical and mechano-electrical feedback as well as force-strain and force-velocity relationships. Moreover, it provides a three-dimensional representation of both the cardiac muscle and the hemodynamics, coupled in a fluid-structure interaction (FSI) model. By leveraging the multiphysics nature of the problem, we discretize it in time with a segregated electrophysiology-force generation-FSI approach, allowing for efficiency and flexibility in the numerical solution. We employ a monolithic approach for the numerical discretization of the FSI problem. We use finite elements for the spatial discretization of partial differential equations. We carry out a numerical simulation on a realistic human left heart model, obtaining results that are qualitatively and quantitatively in agreement with physiological ranges and medical images.
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Affiliation(s)
- Michele Bucelli
- MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | - Alberto Zingaro
- MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | | | - Ivan Fumagalli
- MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | - Luca Dede'
- MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | - Alfio Quarteroni
- MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
- Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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17
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Schwarz EL, Pegolotti L, Pfaller MR, Marsden AL. Beyond CFD: Emerging methodologies for predictive simulation in cardiovascular health and disease. BIOPHYSICS REVIEWS 2023; 4:011301. [PMID: 36686891 PMCID: PMC9846834 DOI: 10.1063/5.0109400] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 12/12/2022] [Indexed: 01/15/2023]
Abstract
Physics-based computational models of the cardiovascular system are increasingly used to simulate hemodynamics, tissue mechanics, and physiology in evolving healthy and diseased states. While predictive models using computational fluid dynamics (CFD) originated primarily for use in surgical planning, their application now extends well beyond this purpose. In this review, we describe an increasingly wide range of modeling applications aimed at uncovering fundamental mechanisms of disease progression and development, performing model-guided design, and generating testable hypotheses to drive targeted experiments. Increasingly, models are incorporating multiple physical processes spanning a wide range of time and length scales in the heart and vasculature. With these expanded capabilities, clinical adoption of patient-specific modeling in congenital and acquired cardiovascular disease is also increasing, impacting clinical care and treatment decisions in complex congenital heart disease, coronary artery disease, vascular surgery, pulmonary artery disease, and medical device design. In support of these efforts, we discuss recent advances in modeling methodology, which are most impactful when driven by clinical needs. We describe pivotal recent developments in image processing, fluid-structure interaction, modeling under uncertainty, and reduced order modeling to enable simulations in clinically relevant timeframes. In all these areas, we argue that traditional CFD alone is insufficient to tackle increasingly complex clinical and biological problems across scales and systems. Rather, CFD should be coupled with appropriate multiscale biological, physical, and physiological models needed to produce comprehensive, impactful models of mechanobiological systems and complex clinical scenarios. With this perspective, we finally outline open problems and future challenges in the field.
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Affiliation(s)
- Erica L. Schwarz
- Departments of Pediatrics and Bioengineering, Stanford University, Stanford, California 94305, USA
| | - Luca Pegolotti
- Departments of Pediatrics and Bioengineering, Stanford University, Stanford, California 94305, USA
| | - Martin R. Pfaller
- Departments of Pediatrics and Bioengineering, Stanford University, Stanford, California 94305, USA
| | - Alison L. Marsden
- Departments of Pediatrics and Bioengineering, Stanford University, Stanford, California 94305, USA
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