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Wernz MM, Voskrebenzev A, Müller RA, Zubke M, Klimeš F, Glandorf J, Czerner C, Wacker F, Olsson KM, Hoeper MM, Hohlfeld JM, Vogel-Claussen J. Feasibility, Repeatability, and Correlation to Lung Function of Phase-Resolved Functional Lung (PREFUL) MRI-derived Pulmonary Artery Pulse Wave Velocity Measurements. J Magn Reson Imaging 2024. [PMID: 38460124 DOI: 10.1002/jmri.29337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/22/2024] [Accepted: 02/22/2024] [Indexed: 03/11/2024] Open
Abstract
BACKGROUND Pulse wave velocity (PWV) in the pulmonary arteries (PA) is a marker of vascular stiffening. Currently, only phase-contrast (PC) MRI-based options exist to measure PA-PWV. PURPOSE To test feasibility, repeatability, and correlation to clinical data of Phase-Resolved Functional Lung (PREFUL) MRI-based calculation of PA-PWV. STUDY TYPE Retrospective. SUBJECTS 79 (26 female) healthy subjects (age range 19-78), 58 (24 female) patients with chronic obstructive pulmonary disease (COPD, age range 40-77), 60 (33 female) patients with suspected pulmonary hypertension (PH, age range 28-85). SEQUENCE 2D spoiled gradient echo, 1.5T. ASSESSMENT PA-PWV was measured from PREFUL-derived cardiac cycles based on the determination of temporal and spatial distance between lung vasculature voxels using a simplified (sPWV) method and a more comprehensive (cPWV) method including more elaborate distance calculation. For 135 individuals, PC MRI-based PWV (PWV-QA) was measured. STATISTICAL TESTS Intraclass-correlation-coefficient (ICC) and coefficient of variation (CoV) were used to test repeatability. Nonparametric tests were used to compare cohorts. Correlation of sPWV/cPWV, PWV-QA, forced expiratory volume in 1 sec (FEV1 ) %predicted, residual volume (RV) %predicted, age, and right heart catheterization (RHC) data were tested. Significance level α = 0.05 was used. RESULTS sPWV and cPWV showed no significant differences between repeated measurements (P-range 0.10-0.92). CoV was generally lower than 15%. COPD and PH patients had significantly higher sPWV and cPWV than healthy subjects. Significant correlation was found between sPWV or cPWV and FEV1 %pred. (R = -0.36 and R = -0.44), but not with RHC (P-range -0.11 - 0.91) or age (P-range 0.23-0.89). Correlation to RV%pred. was significant for cPWV (R = 0.42) but not for sPWV (R = 0.34, P = 0.055). For all cohorts, sPWV and cPWV were significantly correlated with PWV-QA (R = -0.41 and R = 0.48). DATA CONCLUSION PREFUL-derived PWV is feasible and repeatable. PWV is increased in COPD and PH patients and correlates to airway obstruction and hyperinflation. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Marius M Wernz
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Andreas Voskrebenzev
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Robin A Müller
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Maximilian Zubke
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Filip Klimeš
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Julian Glandorf
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Christoph Czerner
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Frank Wacker
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Karen M Olsson
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, Hannover, Germany
| | - Marius M Hoeper
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, Hannover, Germany
| | - Jens M Hohlfeld
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, Hannover, Germany
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany
| | - Jens Vogel-Claussen
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
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Hireche K, Canaud L, Peyron PA, Sakhri L, Serres I, Kamel S, Lounes Y, Gandet T, Alric P. Ex Vivo Comparison of the Elastic Properties of Vascular Substitutes Used for Pulmonary Artery Replacement. J Surg Res 2024; 295:222-230. [PMID: 38039727 DOI: 10.1016/j.jss.2023.10.022] [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: 12/16/2022] [Revised: 10/17/2023] [Accepted: 10/30/2023] [Indexed: 12/03/2023]
Abstract
INTRODUCTION Study aims were to evaluate the elastic properties of vascular substitutes frequently used for pulmonary artery (PA) replacement, and then to compare their compliance and stiffness indexes to those of human PA. METHODS A bench-test pulsatile flow experiment was developed to perfuse human cadaveric vascular substitutes (PA, thoracic aorta, human pericardial conduit), bovine pericardial conduit, and prosthetic vascular substitutes (polytetrafluorethylene and Dacron grafts) at a flow and low pulsed pressure mimicking pulmonary circulation. Intraluminal pressure was measured. An ultrasound system with an echo-tracking function was used to monitor vessel wall movements. The diameter, compliance, and stiffness index were calculated for each vascular substitute and compared to the human PA at mean pressures ranging from 10 to 50 mmHg. RESULTS The compliance of the PA and the thoracic aorta were similar at mean physiological pressures of 10 mmHg and 20 mmHg. The PA was significantly less compliant than the aorta at mean pressures above 30 mmHg (P = 0.017). However, there was no difference in stiffness index between the two substitutes over the entire pressure range. Compared to the PA, human pericardial conduit was less compliant at 10 mmHg (P = 0.033) and stiffer at 10 mmHg (P = 0.00038) and 20 mmHg (P = 0.026). Bovine pericardial conduit and synthetic prostheses were significantly less compliant and stiffer than the PA for mean pressures of 10, 20, and 30 mmHg. There were no differences at 40 and 50 mmHg. CONCLUSIONS Allogenic arterial grafts appear to be the most suitable vascular substitutes in terms of compliance and stiffness for PA replacement.
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Affiliation(s)
- Kheira Hireche
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France; PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France.
| | - Ludovic Canaud
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France; PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France
| | - Pierre Antoine Peyron
- Department of Forensic Medicine, Lapeyronie University Hospital, Montpellier, France
| | - Linda Sakhri
- Groupe Hospitalier Mutualiste de grenoble, Daniel Hollard Cancer Institute, Grenoble, France
| | - Isabelle Serres
- Department of Anatomical Pathology, Gui De Chauliac Hospital, Montpellier, France
| | - Sanaa Kamel
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France
| | - Youcef Lounes
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France; PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France
| | - Thomas Gandet
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France
| | - Pierre Alric
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France; PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France
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Jandl K, Radic N, Zeder K, Kovacs G, Kwapiszewska G. Pulmonary vascular fibrosis in pulmonary hypertension - The role of the extracellular matrix as a therapeutic target. Pharmacol Ther 2023; 247:108438. [PMID: 37210005 DOI: 10.1016/j.pharmthera.2023.108438] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/03/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023]
Abstract
Pulmonary hypertension (PH) is a condition characterized by changes in the extracellular matrix (ECM) deposition and vascular remodeling of distal pulmonary arteries. These changes result in increased vessel wall thickness and lumen occlusion, leading to a loss of elasticity and vessel stiffening. Clinically, the mechanobiology of the pulmonary vasculature is becoming increasingly recognized for its prognostic and diagnostic value in PH. Specifically, the increased vascular fibrosis and stiffening resulting from ECM accumulation and crosslinking may be a promising target for the development of anti- or reverse-remodeling therapies. Indeed, there is a huge potential in therapeutic interference with mechano-associated pathways in vascular fibrosis and stiffening. The most direct approach is aiming to restore extracellular matrix homeostasis, by interference with its production, deposition, modification and turnover. Besides structural cells, immune cells contribute to the level of ECM maturation and degradation by direct cell-cell contact or the release of mediators and proteases, thereby opening a huge avenue to target vascular fibrosis via immunomodulation approaches. Indirectly, intracellular pathways associated with altered mechanobiology, ECM production, and fibrosis, offer a third option for therapeutic intervention. In PH, a vicious cycle of persistent activation of mechanosensing pathways such as YAP/TAZ initiates and perpetuates vascular stiffening, and is linked to key pathways disturbed in PH, such as TGF-beta/BMPR2/STAT. Together, this complexity of the regulation of vascular fibrosis and stiffening in PH allows the exploration of numerous potential therapeutic interventions. This review discusses connections and turning points of several of these interventions in detail.
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Affiliation(s)
- Katharina Jandl
- Division of Pharmacology, Otto Loewi Research Center, Medical University Graz, Graz, Austria; Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Graz, Austria.
| | - Nemanja Radic
- Division of Physiology, Otto Loewi Research Center, Medical University Graz, Graz, Austria
| | - Katarina Zeder
- Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Gabor Kovacs
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Graz, Austria; Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Grazyna Kwapiszewska
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Graz, Austria; Division of Physiology, Otto Loewi Research Center, Medical University Graz, Graz, Austria; Institute for Lung Health, Member of the German Lung Center (DZL), Giessen, Germany
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A patient-specific image-based approach to estimate pulmonary artery stiffness based on vessel constitutive model. Med Eng Phys 2022; 107:103851. [DOI: 10.1016/j.medengphy.2022.103851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/28/2022] [Accepted: 07/10/2022] [Indexed: 11/21/2022]
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Elçioğlu BC, Baydar O, Helvacı F, Karataş C, Aslan G, Kılıç A, Tefik N, Demir B, Gürsoy E, Demirci Y, Ural D, Kanmaz T, Aytekin V, Aytekin S. Evaluation of pulmonary arterial stiffness and comparison with right ventricular functions in patients with cirrhosis preparing for liver transplantation. JOURNAL OF CLINICAL ULTRASOUND : JCU 2022; 50:749-755. [PMID: 35598066 DOI: 10.1002/jcu.23234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/18/2022] [Accepted: 03/28/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVE Pulmonary complications are common in patients with liver cirrhosis. Devolopment of pulmonary hypertension (PH) is associated with a poor prognosis in these patients. Pulmonary arterial stiffness (PAS) is considered an early sign of pulmonary vascular remodeling. The aim of this study is to investigate PAS and compare it with right ventricular (RV) functions in patients with cirrhosis who are scheduled for liver transplantation. METHODS The study included 52 cirrhosis patients (mean age 51.01 ± 12.18 years, male gender 76.9%) who were prepared for liver transplantation and 59 age and sex matched (mean age 51.28 ± 13.63 years, male gender 62.7%) healthy individuals. Patients with left ventricular ejection fraction (LVEF) less than 55%, ischemic heart disease, more than mild valvular heart disease, chronic pulmonary disease, congenital heart disease, rheumatic disease, moderate to high echocardiographic PH probability, rhythm or conduction disorders on electrocardiography were excluded from the study. In addition to conventional echocardiographic parameters, PAS value, pulmonary vascular resistance (PVR) and RV ejection efficiency was calculated by the related formulas with transthoracic echocardiography (TTE). RESULTS Demographic characteristics and cardiovascular risk factors of the groups were similar. PAS, PVR, and sPAP values were found to be significantly higher in the patient group (20.52 ± 6.52 and 13.73 ± 2.05; 1.43 ± 0.15 and 1.27 ± 0.14; 27.69 ± 3.91 and 23.37 ± 3.81 p < 0.001, respectively). RV FAC and RV Ee were significantly lower and RV MPI was significantly higher in the patient group (45.31 ± 3.85 and 49.66 ± 3.62, p < 0.001; 1.69 ± 0.35 and 1.85 ± 0.23, p = 0.005; 0.39 ± 0.07 and 0.33 ± 0.09, p = 0.001, respectively). PAS was significantly correlated with RV FAC and MPI (r = -0.423, p < 0.001; r = 0.301, p = 0.001, respectively). CONCLUSIONS Increased PAS in cirrhosis patients may be associated with early pulmonary vascular involvement. Evaluation of RV functions is important to determine the prognosis in these patients. FAC, MPI, and RV Ee measurements instead of TAPSE or RV S' may be more useful in demonstrating subclinical dysfunction. The correlation of PAS with RV FAC and MPI may indicate that RV subclinical dysfunction is associated with early pulmonary vascular remodeling in patients with liver cirrhosis.
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Affiliation(s)
| | - Onur Baydar
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Füsun Helvacı
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Cihan Karataş
- Organ Transplant Center, Koç University Hospital, Istanbul, Turkey
| | - Gamze Aslan
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Alparslan Kılıç
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Nihal Tefik
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Barış Demir
- Organ Transplant Center, Koç University Hospital, Istanbul, Turkey
| | - Erol Gürsoy
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Yasemin Demirci
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Dilek Ural
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Turan Kanmaz
- Organ Transplant Center, Koç University Hospital, Istanbul, Turkey
| | - Vedat Aytekin
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
| | - Saide Aytekin
- Department of Cardiology, Koç University Hospital, Istanbul, Turkey
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Guo T, He C, Venado A, Zhou Y. Extracellular Matrix Stiffness in Lung Health and Disease. Compr Physiol 2022; 12:3523-3558. [PMID: 35766837 PMCID: PMC10088466 DOI: 10.1002/cphy.c210032] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The extracellular matrix (ECM) provides structural support and imparts a wide variety of environmental cues to cells. In the past decade, a growing body of work revealed that the mechanical properties of the ECM, commonly known as matrix stiffness, regulate the fundamental cellular processes of the lung. There is growing appreciation that mechanical interplays between cells and associated ECM are essential to maintain lung homeostasis. Dysregulation of ECM-derived mechanical signaling via altered mechanosensing and mechanotransduction pathways is associated with many common lung diseases. Matrix stiffening is a hallmark of lung fibrosis. The stiffened ECM is not merely a sequelae of lung fibrosis but can actively drive the progression of fibrotic lung disease. In this article, we provide a comprehensive view on the role of matrix stiffness in lung health and disease. We begin by summarizing the effects of matrix stiffness on the function and behavior of various lung cell types and on regulation of biomolecule activity and key physiological processes, including host immune response and cellular metabolism. We discuss the potential mechanisms by which cells probe matrix stiffness and convert mechanical signals to regulate gene expression. We highlight the factors that govern matrix stiffness and outline the role of matrix stiffness in lung development and the pathogenesis of pulmonary fibrosis, pulmonary hypertension, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. We envision targeting of deleterious matrix mechanical cues for treatment of fibrotic lung disease. Advances in technologies for matrix stiffness measurements and design of stiffness-tunable matrix substrates are also explored. © 2022 American Physiological Society. Compr Physiol 12:3523-3558, 2022.
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Affiliation(s)
- Ting Guo
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Alabama, USA.,Department of Respiratory Medicine, the Second Xiangya Hospital, Central-South University, Changsha, Hunan, China
| | - Chao He
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Alabama, USA
| | - Aida Venado
- Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California, USA
| | - Yong Zhou
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Alabama, USA
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Dieffenbach PB, Aravamudhan A, Fredenburgh LE, Tschumperlin DJ. The Mechanobiology of Vascular Remodeling in the Aging Lung. Physiology (Bethesda) 2022; 37:28-38. [PMID: 34514871 PMCID: PMC8742727 DOI: 10.1152/physiol.00019.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Aging is accompanied by declining lung function and increasing susceptibility to lung diseases. The role of endothelial dysfunction and vascular remodeling in these changes is supported by growing evidence, but underlying mechanisms remain elusive. In this review we summarize functional, structural, and molecular changes in the aging pulmonary vasculature and explore how interacting aging and mechanobiological cues may drive progressive vascular remodeling in the lungs.
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Affiliation(s)
- Paul B. Dieffenbach
- 1Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Aja Aravamudhan
- 2Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
| | - Laura E. Fredenburgh
- 1Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Daniel J. Tschumperlin
- 2Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
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Branch Pulmonary Artery Regurgitation in Repaired Tetralogy of Fallot: Correlation with Pulmonary Artery Morphology, Distensibility, and Right Ventricular Function. Tomography 2021; 7:412-423. [PMID: 34564298 PMCID: PMC8482212 DOI: 10.3390/tomography7030036] [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: 07/09/2021] [Revised: 08/03/2021] [Accepted: 08/24/2021] [Indexed: 12/02/2022] Open
Abstract
Background: The aim was to determine the effect of pulmonary artery (PA) morphology on the branch pulmonary artery-regurgitation fraction (BPA-RF), the relationship of pulmonary insufficiency (PI) to BPA-RF and PA-distensibility, and factors (BPA-RF and PA-distensibility) associated with right ventricular function (RVF) in repaired tetralogy of Fallot (rTOF). Methods: A total of 182 rTOF patients (median age 17.1 years) were analyzed for length, angle of PA, BPA-RF, PI, and PA-distensibility, using magnetic resonance imaging. Results: The left PA had a significant greater RF than the right PA (median (interquartile range)): LPA 43.1% (32.6–51.5) and RPA 35.2% (24.7–44.7), p < 0.001. The LPA was shorter with a narrower angle than the RPA (p < 0.001). The anatomy of the branch-PA was not a factor for the greater LPA-RF (odds ratio, 95% confidence interval: CI, p-value): length 0.44 (0.95–2.00), p = 0.28; angle 0.63 (0.13–2.99), p = 0.56. There was a strong positive correlation between PI and BPA-RF-coefficients (95% CI), p-value: LPA 0.78% (0.70–0.86), p < 0.001; RPA 0.78% (0.71–0.84), p < 0.001 and between BPA-RF and distensibility-coefficients (95%CI), p-value: LPA 0.73% (0.37–1.09), p < 0.001; RPA 1.63% (1.22–2.03), p < 0.001, respectively. The adjusted BPA-RF did not predict RVF, RPA (p = 0.434), LPA (p = 0.268). Conclusions: PA morphology is not a significant factor for the differential BPA-RF. The vascular wall in rTOF patients responds to chronic increased intravascular volume by increasing distensibility. BPA-RF is not a determinant of RVF.
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Christou H, Michael Z, Spyropoulos F, Chen Y, Rong D, Khalil RA. Carbonic anhydrase inhibition improves pulmonary artery reactivity and nitric oxide-mediated relaxation in sugen-hypoxia model of pulmonary hypertension. Am J Physiol Regul Integr Comp Physiol 2021; 320:R835-R850. [PMID: 33826428 PMCID: PMC8285620 DOI: 10.1152/ajpregu.00362.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/11/2021] [Accepted: 04/06/2021] [Indexed: 11/22/2022]
Abstract
Pulmonary hypertension (PH) is a serious disease with pulmonary arterial fibrotic remodeling and limited responsiveness to vasodilators. Our data suggest that mild acidosis induced by carbonic anhydrase inhibition could ameliorate PH, but the vascular mechanisms are unclear. We tested the hypothesis that carbonic anhydrase inhibition ameliorates PH by improving pulmonary vascular reactivity and relaxation mechanisms. Male Sprague-Dawley rats were either control normoxic (Nx), or injected with Sugen 5416 (20 mg/kg, sc) and subjected to hypoxia (9% O2) (Su + Hx), or Su + Hx treated with acetazolamide (ACTZ, 100 mg/kg/day, in drinking water). After measuring the hemodynamics, right ventricular hypertrophy was assessed by Fulton's Index; vascular function was measured in pulmonary artery, aorta, and mesenteric arteries; and pulmonary arteriolar remodeling was assessed in lung sections. Right ventricular systolic pressure and Fulton's Index were increased in Su + Hx and reduced in Su + Hx + ACTZ rats. Pulmonary artery contraction to KCl and phenylephrine were reduced in Su + Hx and improved in Su + Hx + ACTZ. Acetylcholine (ACh)-induced relaxation and nitrate/nitrite production were reduced in pulmonary artery of Su + Hx and improved in Su + Hx + ACTZ. ACh relaxation was blocked by nitric oxide (NO) synthase and guanylate cyclase inhibitors, supporting a role of NO-cGMP. Sodium nitroprusside (SNP)-induced relaxation was reduced in pulmonary artery of Su + Hx, and ACTZ enhanced relaxation to SNP. Contraction/relaxation were not different in aorta or mesenteric arteries of all groups. Pulmonary arterioles showed wall thickening in Su + Hx that was ameliorated in Su + Hx + ACTZ. Thus, amelioration of pulmonary hemodynamics during carbonic anhydrase inhibition involves improved pulmonary artery reactivity and NO-mediated relaxation and may enhance responsiveness to vasodilator therapies in PH.
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Affiliation(s)
- Helen Christou
- Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Zoe Michael
- Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | - Fotios Spyropoulos
- Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Yunfei Chen
- Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Dan Rong
- Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Raouf A Khalil
- Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
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Erdol MA, Acar B, Ertem AG, Karanfil M, Yayla Ç, Demırtas K, Aladağ P, Sönmezer MÇ, Kiliç EK, Hatipoğlu ÇA, Erdinc FS, Tulek N, Akcay AB. Assessment of Pulmonary Arterial Hemodynamic and Vascular Changes by Pulmonary Pulse Transit Time in Patients with Human Immunodeficiency Virus Infection. J Cardiovasc Echogr 2021; 31:6-10. [PMID: 34221879 PMCID: PMC8230153 DOI: 10.4103/jcecho.jcecho_103_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/21/2020] [Accepted: 12/08/2020] [Indexed: 11/04/2022] Open
Abstract
Introduction Pulmonary arterial hypertension and human immunodeficiency virus (HIV) infection is a well-known association. Pulmonary pulse transit time (pPTT) is a recent echocardiographic marker that might be used for evaluation of pulmonary arterial stiffness (PAS) in patients with HIV infection. We aimed to investigate whether pPTT elevated in patients with HIV infection compared to healthy controls and its association with echocardiographic indices of right ventricular functions. Materials and Methods Fifty HIV (+) patients from infectious disease outpatient clinics and fifty age- and sex-matched HIV (-) healthy volunteers were enrolled in this study. pPTT was measured from pulmonary vein flow velocity as the time interval between the R-wave in the electrocardiography and corresponding peak late systolic was then calculated as the mean from two separate pw-Doppler measurements. Results pPTT, tricuspid annular peak systolic excursion (TAPSE) and right ventricle fractional area change (FAC) were significantly lower in patients with HIV than control patients (177.1 ± 34.9 vs. 215.7 ± 35.7 msn, P < 0.001; 2.33 ± 0.28 vs. 2.19 ± 0.22, P = 0.039; 45 [4.25] vs. 41.1 [4.0], P = 0.032, respectively). pPTT was positively correlated with FAC, TAPSE and cluster of differentiation 4 count (r = 0.210; P = 0.036, r = 0.256; P = 0.041, r = 0.304; P = 0.044, respectively). Conclusion Our study showed that pPTT, TAPSE, and right ventricle FAC levels were lower in patients with HIV infection. pPTT is an important predictor in patients with HIV expected to develop pulmonary vascular pathology.
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Affiliation(s)
- Mehmet Akif Erdol
- Department of Cardiology, University of Health Sciences, Ankara City Hospital, Ankara, Turkey
| | - Burak Acar
- Department of Cardiology, Kocaeli University, Kocaeli, Turkey
| | - Ahmet Goktug Ertem
- Department of Cardiology, University of Health Sciences, Ankara City Hospital, Ankara, Turkey
| | - Mustafa Karanfil
- Department of Cardiology, University of Health Sciences, Ankara City Hospital, Ankara, Turkey
| | - Çağrı Yayla
- Department of Cardiology, University of Health Sciences, Ankara City Hospital, Ankara, Turkey
| | - Koray Demırtas
- Department of Cardiology, University of Health Sciences, Ankara City Hospital, Ankara, Turkey
| | - Pelin Aladağ
- Department of Cardiology, Kocaeli University, Kocaeli, Turkey
| | - Meliha Çağla Sönmezer
- Department of Infectious Diseases and Clinical Microbiology, Hacettepe University, Ankara, Turkey
| | - Esra Kaya Kiliç
- Department of Infectious Diseases and Clinical Microbiology, Ankara Training and Research Hospital, Ankara, Turkey
| | - Çiğdem Ataman Hatipoğlu
- Department of Infectious Diseases and Clinical Microbiology, Ankara Training and Research Hospital, Ankara, Turkey
| | - Fatma Sebnem Erdinc
- Department of Infectious Diseases and Clinical Microbiology, Ankara Training and Research Hospital, Ankara, Turkey
| | - Necla Tulek
- Department of Infectious Diseases and Clinical Microbiology, Atilim University, Ankara, Turkey
| | - Adnan Burak Akcay
- Department of Cardiology, University of Health Sciences, Ankara City Hospital, Ankara, Turkey
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11
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Pourmodheji R, Jiang Z, Tossas-Betancourt C, Figueroa CA, Baek S, Lee LC. Inverse modeling framework for characterizing patient-specific microstructural changes in the pulmonary arteries. J Mech Behav Biomed Mater 2021; 119:104448. [PMID: 33836475 DOI: 10.1016/j.jmbbm.2021.104448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/18/2021] [Accepted: 03/02/2021] [Indexed: 10/21/2022]
Abstract
Microstructural changes in the pulmonary arteries associated with pulmonary arterial hypertension (PAH) is not well understood and characterized in humans. To address this issue, we developed and applied a patient-specific inverse finite element (FE) modeling framework to characterize mechanical and structural changes of the micro-constituents in the proximal pulmonary arteries using in-vivo pressure measurements and magnetic resonance images. The framework was applied using data acquired from a pediatric PAH patient and a heart transplant patient with normal pulmonary arterial pressure, which serves as control. Parameters of a constrained mixture model that are associated with the structure and mechanical properties of elastin, collagen fibers and smooth muscle cells were optimized to fit the patient-specific pressure-diameter responses of the main pulmonary artery. Based on the optimized parameters, individual stress and linearized stiffness resultants of the three tissue constituents, as well as their aggregated values, were estimated in the pulmonary artery. Aggregated stress resultant and stiffness are, respectively, 4.6 and 3.4 times higher in the PAH patient than the control subject. Stress and stiffness resultants of each tissue constituent are also higher in the PAH patient. Specifically, the mean stress resultant is highest in elastin (PAH: 69.96, control: 14.42 kPa-mm), followed by those in smooth muscle cell (PAH: 13.95, control: 4.016 kPa-mm) and collagen fibers (PAH: 13.19, control: 2.908 kPa-mm) in both the PAH patient and the control subject. This result implies that elastin may be the key load-bearing constituent in the pulmonary arteries of the PAH patient and the control subject.
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Affiliation(s)
- Reza Pourmodheji
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
| | - Zhenxiang Jiang
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | | | - C Alberto Figueroa
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA; Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Seungik Baek
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | - Lik-Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
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12
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Zambrano BA, McLean N, Zhao X, Tan JL, Zhong L, Figueroa CA, Lee LC, Baek S. Patient-Specific Computational Analysis of Hemodynamics and Wall Mechanics and Their Interactions in Pulmonary Arterial Hypertension. Front Bioeng Biotechnol 2021; 8:611149. [PMID: 33634080 PMCID: PMC7901991 DOI: 10.3389/fbioe.2020.611149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/15/2020] [Indexed: 11/13/2022] Open
Abstract
Vascular wall stiffness and hemodynamic parameters are potential biomechanical markers for detecting pulmonary arterial hypertension (PAH). Previous computational analyses, however, have not considered the interaction between blood flow and wall deformation. Here, we applied an established computational framework that utilizes patient-specific measurements of hemodynamics and wall deformation to analyze the coupled fluid-vessel wall interaction in the proximal pulmonary arteries (PA) of six PAH patients and five control subjects. Specifically, we quantified the linearized stiffness (E), relative area change (RAC), diastolic diameter (D), regurgitant flow, and time-averaged wall shear stress (TAWSS) of the proximal PA, as well as the total arterial resistance (R t ) and compliance (C t ) at the distal pulmonary vasculature. Results found that the average proximal PA was stiffer [median: 297 kPa, interquartile range (IQR): 202 kPa vs. median: 75 kPa, IQR: 5 kPa; P = 0.007] with a larger diameter (median: 32 mm, IQR: 5.25 mm vs. median: 25 mm, IQR: 2 mm; P = 0.015) and a reduced RAC (median: 0.22, IQR: 0.10 vs. median: 0.42, IQR: 0.04; P = 0.004) in PAH compared to our control group. Also, higher total resistance (R t ; median: 6.89 mmHg × min/l, IQR: 2.16 mmHg × min/l vs. median: 3.99 mmHg × min/l, IQR: 1.15 mmHg × min/l; P = 0.002) and lower total compliance (C t ; median: 0.13 ml/mmHg, IQR: 0.15 ml/mmHg vs. median: 0.85 ml/mmHg, IQR: 0.51 ml/mmHg; P = 0.041) were observed in the PAH group. Furthermore, lower TAWSS values were seen at the main PA arteries (MPAs) of PAH patients (median: 0.81 Pa, IQR: 0.47 Pa vs. median: 1.56 Pa, IQR: 0.89 Pa; P = 0.026) compared to controls. Correlation analysis within the PAH group found that E was directly correlated to the PA regurgitant flow (r = 0.84, P = 0.018) and inversely related to TAWSS (r = -0.72, P = 0.051). Results suggest that the estimated elastic modulus E may be closely related to PAH hemodynamic changes in pulmonary arteries.
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Affiliation(s)
- Byron A. Zambrano
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, TX, United States
| | - Nathan McLean
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| | - Xiaodan Zhao
- National Heart Centre Singapore, Singapore, Singapore
| | - Ju-Le Tan
- National Heart Centre Singapore, Singapore, Singapore
| | - Liang Zhong
- National Heart Centre Singapore, Singapore, Singapore
- Duke-National University of Singapore, Singapore, Singapore
| | - C. Alberto Figueroa
- Departments of Biomedical Engineering and Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| | - Seungik Baek
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
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13
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Virtual Histology to Evaluate Mechanisms of Pulmonary Artery Lumen Enlargement in Response to Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension. J Clin Med 2020; 9:jcm9061655. [PMID: 32492788 PMCID: PMC7355673 DOI: 10.3390/jcm9061655] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/16/2020] [Accepted: 05/26/2020] [Indexed: 11/29/2022] Open
Abstract
Chronic thromboembolic pulmonary hypertension (CTEPH) results from an obstruction of pulmonary arteries (PAs) by organized thrombi. The stenosed PAs are targeted during balloon pulmonary angioplasty (BPA). We aimed to evaluate the mechanism of BPA in inoperable patients with CTEPH. We analyzed stenosed PAs with intravascular grey-scale ultrasound (IVUS) to determine the cross-sectional area (CSA) of arterial lumen and of organized thrombi. The composition of organized thrombi was assessed using virtual histology. We distinguished two mechanisms of BPA: Type A with dominant vessel stretching, and type B with dominant thrombus compression. PAs were assessed before (n = 159) and after (n = 98) BPA in 20 consecutive patients. Organized thrombi were composed of dark-green (57.1 (48.0–64.0)%), light-green (34.0 (21.4–46.4)%), red (6.4 (2.9–11.7)%;) and white (0.2 (0.0–0.9)%) components. The mechanism type depended on vessel diameter (OR = 1.09(1.01–1.17); p = 0.03). In type B mechanism, decrease in the amount of light-green component positively correlated with an increase in lumen area after BPA (r = 0.50; p = 0.001). The mechanism of BPA depends on the diameter of the vessel. Dilation of more proximal PAs depends mainly on stretching of the vessel wall while dilation of smaller PAs depends on compression of the organized thrombi. The composition of the organized thrombi contributes to the effect of BPA.
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14
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Hebbar UU, Banerjee RK. Influence of coupled hemodynamics-arterial wall interaction on compliance in a realistic pulmonary artery with variable intravascular wall properties. Med Image Anal 2019; 57:56-71. [PMID: 31279216 DOI: 10.1016/j.media.2019.06.008] [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: 12/17/2018] [Revised: 05/01/2019] [Accepted: 06/19/2019] [Indexed: 11/15/2022]
Abstract
Pulmonary hypertension is characterized by elevation of pulmonary artery (PA) pressure (p) and structural remodeling of the PA wall, leading to reduction in arterial compliance (c). As a step towards improving diagnosis of pulmonary disease, we use the PA branch geometry (main pulmonary artery (MPA) branching into left (LPA) and right (RPA) pulmonary arteries) obtained from MRI in conjunction with an inverse algorithm to obtain the pre-stress level in the artery walls. Next, a coupled blood-wall interaction (BWI) calculation provides hemodynamic information as well as compliance of the PA walls. We show that the computed load-free geometry from the inverse algorithm exhibits a 27.8% lower inner diameter (d) and 18.5% lower outer d compared to the in vivo geometry from MRI. Further, the mean p computed from the BWI computation in the main PA (pMPA-n) is within 4% of the mean pMPA-e (n-numerical; e-experimental). Also, the mean Q computed in the left PA (QLPA-n) is within 10% of the mean QLPA-e. Finally, the compliance cMPA-n is computed to be 27% lower than cMPA-e, while the cLPA-n is computed to be 20.4% lower than cLPA-e. Importantly, the PA shows significant intra-vascular variation in compliance, with the MPA showing higher overall compliance compared to the LPA (3.5-4 times).
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Affiliation(s)
- Ullhas U Hebbar
- 593 Rhodes Hall, Department of Mechanical Engineering, University of Cincinnati, OH, 45221, United States
| | - Rupak K Banerjee
- 593 Rhodes Hall, Department of Mechanical Engineering, University of Cincinnati, OH, 45221, United States.
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15
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Abstract
The pulmonary circulation carries deoxygenated blood from the systemic veins through the pulmonary arteries to be oxygenated in the capillaries that line the walls of the pulmonary alveoli. The pulmonary circulation carries the cardiac output with a relatively low driving pressure, and so differs considerably in structure and function from the systemic circulation to maintain a low-resistance vascular system. The pulmonary circulation is often considered to be a quasi-static system in both experimental and computational studies of pulmonary perfusion and its matching to ventilation (air flow) for exchange. However, the system is highly dynamic, with cardiac output and regional perfusion changing with posture, exercise, and over time. Here we review this dynamic system, with a focus on understanding the physiology of pulmonary vascular dynamics across spatial and temporal scales, and the changes to these dynamics that are reflective of disease. © 2019 American Physiological Society. Compr Physiol 9:1081-1100, 2019.
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Affiliation(s)
- Alys Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Merryn Tawhai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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16
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Ando Y, Ochiai Y, Tokunaga S, Hisahara M, Baba H, Miyagi C, Takigawa T. Size and Stiffness of the Pulmonary Autograft after the Ross Procedure in Children. Pediatr Cardiol 2019; 40:776-783. [PMID: 30734094 DOI: 10.1007/s00246-019-02064-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/29/2019] [Indexed: 11/24/2022]
Abstract
Progressive dilatation of the pulmonary autograft is one of the greatest concerns after the Ross procedure. Increased stress in the arterial wall may cause changes in the elastic properties of the pulmonary autograft, and thus lead to pathological dilatation. The present study aimed to investigate the changes in the autograft diameter and stiffness during follow-up after the Ross procedure. A total of ten patients underwent the Ross procedure at our institution between 2003 and 2011. Echocardiography was used to measure the diameters of the pulmonary autograft at the level of the annulus, sinus of Valsalva, and sinotubular junction. The stiffness index was calculated from the angiographic data, and compared with that of 16 age-matched control children. The diameters of the pulmonary autograft increased throughout the follow-up period, particularly at the level of the sinus of Valsalva and at the sinotubular junction. The aortic root was stiffer in Ross patients compared with control children (7.9 ± 1.8 vs. 3.9 ± 0.7 immediately postoperatively, p < 0.01; 10.1 ± 2.8 vs. 4.2 ± 1.4 at 5 years postoperatively, p < 0.01). Although no significant relationship was found between the stiffness index and the autograft diameter, the stiffness index tended to increase over time. Dilatation of the pulmonary autograft was accompanied by progressive change in aortic stiffness. Longer follow-up is warranted to clarify the impact of this change in aortic stiffness on autograft failure.
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Affiliation(s)
- Yusuke Ando
- Department of Cardiovascular Surgery, Japan Community Health Care Organization Kyushu Hospital, 1-8-1 Kishinoura, Yahatanishi-ku, Kitakyushu, 806-8501, Japan.
| | - Yoshie Ochiai
- Department of Cardiovascular Surgery, Japan Community Health Care Organization Kyushu Hospital, 1-8-1 Kishinoura, Yahatanishi-ku, Kitakyushu, 806-8501, Japan
| | - Shigehiko Tokunaga
- Department of Cardiovascular Surgery, Japan Community Health Care Organization Kyushu Hospital, 1-8-1 Kishinoura, Yahatanishi-ku, Kitakyushu, 806-8501, Japan
| | - Manabu Hisahara
- Department of Cardiovascular Surgery, Japan Community Health Care Organization Kyushu Hospital, 1-8-1 Kishinoura, Yahatanishi-ku, Kitakyushu, 806-8501, Japan
| | - Hironori Baba
- Department of Cardiovascular Surgery, Japan Community Health Care Organization Kyushu Hospital, 1-8-1 Kishinoura, Yahatanishi-ku, Kitakyushu, 806-8501, Japan
| | - Chihiro Miyagi
- Department of Cardiovascular Surgery, Japan Community Health Care Organization Kyushu Hospital, 1-8-1 Kishinoura, Yahatanishi-ku, Kitakyushu, 806-8501, Japan
| | - Tomoya Takigawa
- Department of Cardiovascular Surgery, Japan Community Health Care Organization Kyushu Hospital, 1-8-1 Kishinoura, Yahatanishi-ku, Kitakyushu, 806-8501, Japan
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17
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Pulmonary Artery Elastic Properties After Balloon Pulmonary Angioplasty in Patients With Inoperable Chronic Thromboembolic Pulmonary Hypertension. Can J Cardiol 2019; 35:422-429. [PMID: 30935632 DOI: 10.1016/j.cjca.2019.01.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/27/2019] [Accepted: 01/27/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND A significant proportion of the right ventricular afterload is determined by the elastic properties of the pulmonary artery (PA). We aimed to assess the effect of balloon pulmonary angioplasty (BPA) on PA elastic properties in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). METHODS We enrolled adult patients with CTEPH treated with BPA and controls without PH. Total PA compliance (CPa) was calculated as stroke volume/PA pulse pressure. PA distensibility (DC) and compliance (CC) coefficients were assessed by intravascular ultrasound to denote local elastic properties of the treated PA segments. RESULTS We performed 103 BPA sessions in 17 patients with CTEPH (5 men [29%], aged 66 [64 to 73] years) who were followed for 6 (5 to 7) months after the last BPA. The median time between BPA sessions was 39 (28 to 52) days. The CPa, CC, and DC were lower in patients with CTEPH than in controls without PH (n = 10). Complete BPA treatment led to increase of CPa from 1.02 (0.70 to 1.39) to 2.08 (1.49 to 2.39) mL/mm Hg (P < 0.001) at the 6-month follow up, and this increase was in proportion to a decrease in pulmonary vascular resistance (PVR) (R2 = 0.74; P = 0.001). CPa increased immediately after BPA session by 0.13 (-0.05; 0.33) mL/mm Hg (P = 0.001) and remained unchanged until the next BPA session. CC and DC exhibited no immediate change after catheter balloon inflation (Δ=0 [-0.03; 0.02] mm2/mm Hg, P = 0.52, and Δ = 0 [-0.13; 0.13] %/mm Hg, P = 0.91, respectively) and remained unchanged at the 6-month follow-up. CONCLUSIONS BPA improved total CPa in proportion to a decrease in PVR despite no improvement in local elastic properties of the treated PA segments.
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Wang J, Yu M, Xu J, Cheng Y, Li X, Wei G, Wang H, Kong H, Xie W. Glucagon-like peptide-1 (GLP-1) mediates the protective effects of dipeptidyl peptidase IV inhibition on pulmonary hypertension. J Biomed Sci 2019; 26:6. [PMID: 30634956 PMCID: PMC6330403 DOI: 10.1186/s12929-019-0496-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 01/02/2019] [Indexed: 12/17/2022] Open
Abstract
Background Pulmonary hypertension (PH) is a progressive disease leading to death ultimately. Our recently published data demonstrated that inhibiting dipeptidyl peptidase IV (DPP-4) alleviated pulmonary vascular remodeling in experimental PH. However, whether glucagon-like peptide-1 (GLP-1) mediated the protective effect of DPP-4 inhibition (DPP-4i) on PH is unclear. Results In the present study, GLP-1 receptor antagonist (exendin-3) abolished the protective effects of DPP-4 inhibitor (sitagliptin) on right ventricular systolic pressure (RVSP) and pulmonary vascular remodeling (PVR) in monocrotaline (MCT, 60 mg/kg)-induced PH in rat. Notably, activation of GLP-1 receptor by GLP-1 analogue liraglutide directly attenuated RVSP and PVR in MCT-induced PH, as well as bleomycin- and chronic hypoxia-induced PH. Moreover, liraglutide potently inhibited MCT-induced inflammation and suppressed MCT-induced down-regulation of vascular endothelial marker (VE-cadherin and vWF) in lung. In vitro studies showed liraglutide reversed TGF-β1 (5 ng/ml) combining IL-1β (5 ng/ml) induced endothelial-mesenchymal transition (EndMT) in human umbilical vein endothelial cells (HUVECs), which could be abolished by GLP-1 receptor antagonist (exendin-3). Furtermore, liraglutide suppressed TGF-β1-IL-1β-induced phosphorylation of both Smad3 and ERK1/2. Conclusions Our data suggest that GLP-1 mediated the protective effects of DPP-4i on pulmonary vascular and RV remodeling in experimental PH, which may be attributed to the inhibitory effect on EndMT.
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Affiliation(s)
- Jingjing Wang
- Department of Respiratory Medicine, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, 200433, People's Republic of China
| | - Min Yu
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, People's Republic of China
| | - Jian Xu
- Department of Respiratory Medicine, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, 200433, People's Republic of China
| | - Yusheng Cheng
- Department of Respiratory and Critical Care Medicine, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, 241001, People's Republic of China
| | - Xiang Li
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, People's Republic of China
| | - Guihong Wei
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, People's Republic of China
| | - Hong Wang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, People's Republic of China
| | - Hui Kong
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, People's Republic of China.
| | - Weiping Xie
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, People's Republic of China.
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Sznajder M, Dzikowska-Diduch O, Kurnicka K, Roik M, Wretowski D, Pruszczyk P, Kostrubiec M. Increased systemic arterial stiffness in patients with chronic thromboembolic pulmonary hypertension. Cardiol J 2018; 27:742-748. [PMID: 30234892 DOI: 10.5603/cj.a2018.0109] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 09/13/2018] [Accepted: 03/18/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of venous thromboembolism (VTE) resulting from non-dissolving thromboemboli in the pulmonary arteries. Previous observations indicate a higher prevalence of atherosclerosis and cardiovascular risk factors in patients with VTE and CTEPH. The purpose of the present study was to evaluate the arterial stiffening assessed by pulse wave velocity (PWV), a marker of arterial stiffness, in CTEPH patients in comparison with a matched control group (CG). METHODS The study group consisted of 26 CTEPH patients (9 male and 17 female, age 69 ± 10 years) and 22 CG (10 male, 12 female, age 67 ± 8 years). In all subjects a physical examination, carotid-femoral PWV and transthoracic echocardiography were performed. Right heart catheterization was done in all CTEPH. RESULTS Chronic tromboembolic pulmonary hypertension patients had significantly higher PWV than CG (10.3 ± 2.5 m/s vs. 9 ± 1.3 m/s, p < 0.05), even though systolic blood pressure was higher in CG (120 ± 11 vs. 132 ± 14 mmHg, p = 0.002). PWV correlated only with age and pulmonary vascular resistance (PVR) in CTEPH (r = 0.45, p = 0.03 and r = 0.43, p = 0.03, respectively). Arterial stiffening defined as PWV > 10 m/s was found in 11 (42%) CTEPH patients and in 5 (23%) cases from CG (p = 0.13). CTEPH patients with PWV > 10 m/s were older (74 ± 8 vs. 66 ± 10 years, p < 0.05), had decreased oxygen saturation (SaO2 89 [73-96]% vs. 96 [85-98]%, p < 0.01) and tended to have higher PVR (8.1 [3.1-14.0] vs. 5.2 [3.1-12.7] HRU, p = 0.10). CONCLUSIONS Arterial stiffness, assessed with PWV, is increased in CTEPH. The elevated PWV is associated with older age, lower SaO2 and higher PVR in CTEPH.
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Affiliation(s)
- Monika Sznajder
- Department of Internal Medicine and Cardiology with Venous Thromboembolism Center, Medical University of Warsaw, 4 Lindleya St, 02-005 Warsaw, Poland
| | - Olga Dzikowska-Diduch
- Department of Internal Medicine and Cardiology with Venous Thromboembolism Center, Medical University of Warsaw, 4 Lindleya St, 02-005 Warsaw, Poland
| | - Katarzyna Kurnicka
- Department of Internal Medicine and Cardiology with Venous Thromboembolism Center, Medical University of Warsaw, 4 Lindleya St, 02-005 Warsaw, Poland
| | - Marek Roik
- Department of Internal Medicine and Cardiology with Venous Thromboembolism Center, Medical University of Warsaw, 4 Lindleya St, 02-005 Warsaw, Poland
| | - Dominik Wretowski
- Department of Internal Medicine and Cardiology with Venous Thromboembolism Center, Medical University of Warsaw, 4 Lindleya St, 02-005 Warsaw, Poland
| | - Piotr Pruszczyk
- Department of Internal Medicine and Cardiology with Venous Thromboembolism Center, Medical University of Warsaw, 4 Lindleya St, 02-005 Warsaw, Poland
| | - Maciej Kostrubiec
- Department of Internal Medicine and Cardiology with Venous Thromboembolism Center, Medical University of Warsaw, 4 Lindleya St, 02-005 Warsaw, Poland.
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20
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Dieffenbach PB, Maracle M, Tschumperlin DJ, Fredenburgh LE. Mechanobiological Feedback in Pulmonary Vascular Disease. Front Physiol 2018; 9:951. [PMID: 30090065 PMCID: PMC6068271 DOI: 10.3389/fphys.2018.00951] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 06/28/2018] [Indexed: 01/06/2023] Open
Abstract
Vascular stiffening in the pulmonary arterial bed is increasingly recognized as an early disease marker and contributor to right ventricular workload in pulmonary hypertension. Changes in pulmonary artery stiffness throughout the pulmonary vascular tree lead to physiologic alterations in pressure and flow characteristics that may contribute to disease progression. These findings have led to a greater focus on the potential contributions of extracellular matrix remodeling and mechanical signaling to pulmonary hypertension pathogenesis. Several recent studies have demonstrated that the cellular response to vascular stiffness includes upregulation of signaling pathways that precipitate further vascular remodeling, a process known as mechanobiological feedback. The extracellular matrix modifiers, mechanosensors, and mechanotransducers responsible for this process have become increasingly well-recognized. In this review, we discuss the impact of vascular stiffening on pulmonary hypertension morbidity and mortality, evidence in favor of mechanobiological feedback in pulmonary hypertension pathogenesis, and the major contributors to mechanical signaling in the pulmonary vasculature.
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Affiliation(s)
- Paul B Dieffenbach
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, United States
| | - Marcy Maracle
- Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Daniel J Tschumperlin
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| | - Laura E Fredenburgh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, United States
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21
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Sun W, Chan SY. Pulmonary Arterial Stiffness: An Early and Pervasive Driver of Pulmonary Arterial Hypertension. Front Med (Lausanne) 2018; 5:204. [PMID: 30073166 PMCID: PMC6058030 DOI: 10.3389/fmed.2018.00204] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 06/28/2018] [Indexed: 12/12/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a historically neglected and highly morbid vascular disease that leads to right heart failure and, in some cases, death. The molecular origins of this disease have been poorly defined, and as such, current pulmonary vasodilator therapies do not cure or reverse this disease. Although extracellular matrix (ECM) remodeling and pulmonary arterial stiffening have long been associated with end-stage PAH, recent studies have reported that such vascular stiffening can occur early in pathogenesis. Furthermore, there is emerging evidence that ECM stiffening may represent a key first step in pathogenic reprogramming and molecular crosstalk among endothelial, smooth muscle, and fibroblast cells in the remodeled pulmonary vessel. Such processes represent the convergence of activation of a number of specific mechanoactivated signaling pathways, microRNAs, and metabolic pathways in pulmonary vasculature. In this review, we summarize the contemporary understanding of vascular stiffening as a driver of PAH, its mechanisms, potential therapeutic targets and clinical perspectives. Of note, early intervention targeting arterial stiffness may break the vicious cycle of PAH progression, leading to outcome improvement which has not been demonstrated by current vasodilator therapy.
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Affiliation(s)
| | - Stephen Y. Chan
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA, United States
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22
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Hemnes AR, Humbert M. Pathobiology of pulmonary arterial hypertension: understanding the roads less travelled. Eur Respir Rev 2017; 26:26/146/170093. [DOI: 10.1183/16000617.0093-2017] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 12/08/2017] [Indexed: 01/09/2023] Open
Abstract
The pathobiology of pulmonary arterial hypertension (PAH) is complex and incompletely understood. Although three pathogenic pathways have been relatively well characterised, it is widely accepted that dysfunction in a multitude of other cellular processes is likely to play a critical role in driving the development of PAH. Currently available therapies, which all target one of the three well-characterised pathways, provide significant benefits for patients; however, PAH remains a progressive and ultimately fatal disease. The development of drugs to target alternative pathogenic pathways is, therefore, an attractive proposition and one that may complement existing treatment regimens to improve outcomes for patients. Considerable research has been undertaken to identify the role of the less well-understood pathways and in this review we will highlight some of the key discoveries and the potential for utility as therapeutic targets.
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23
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Christou H, Hudalla H, Michael Z, Filatava EJ, Li J, Zhu M, Possomato-Vieira JS, Dias-Junior C, Kourembanas S, Khalil RA. Impaired Pulmonary Arterial Vasoconstriction and Nitric Oxide-Mediated Relaxation Underlie Severe Pulmonary Hypertension in the Sugen-Hypoxia Rat Model. J Pharmacol Exp Ther 2017; 364:258-274. [PMID: 29212831 DOI: 10.1124/jpet.117.244798] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/04/2017] [Indexed: 02/06/2023] Open
Abstract
Pulmonary vasoreactivity could determine the responsiveness to vasodilators and, in turn, the prognosis of pulmonary hypertension (PH). We hypothesized that pulmonary vasoreactivity is impaired, and we examined the underlying mechanisms in the Sugen-hypoxia rat model of severe PH. Male Sprague-Dawley rats were injected with Sugen (20 mg/kg s.c.) and exposed to hypoxia (9% O2) for 3 weeks, followed by 4 weeks in normoxia (Su/Hx), or treated with Sugen alone (Su) or hypoxia alone (Hx) or neither (Nx). After hemodynamic measurements, the heart was assessed for right ventricular hypertrophy (Fulton's index); the pulmonary artery, aorta, and mesenteric arteries were isolated for vascular function studies; and contractile markers were measured in pulmonary arteries using quantitative polymerase chain reaction (PCR). Other rats were used for morphometric analysis of pulmonary vascular remodeling. Right ventricular systolic pressure and Fulton's index were higher in Su/Hx versus Su, Hx, and Nx rats. Pulmonary vascular remodeling was more prominent in Su/Hx versus Nx rats. In pulmonary artery rings, contraction to high KCl (96 mM) was less in Su/Hx versus Nx and Su, and phenylephrine-induced contraction was reduced in Su/Hx versus Nx, Hx, and Su. Acetylcholine (ACh)-induced relaxation was less in Su/Hx versus Nx and Hx, suggesting reduced endothelium-dependent vasodilation. ACh relaxation was inhibited by nitric oxide synthase (NOS) and guanylate cyclase blockade in all groups, suggesting a role of the NO-cGMP pathway. Nitrate/nitrite production in response to ACh was less in Su/Hx versus Nx, supporting reduced endothelial NO production. Sodium nitroprusside (10-8 M) caused less relaxation in Su/Hx versus Nx, Hx, and Su, suggesting a decreased responsiveness of vascular smooth muscle (VSM) to vasodilators. Neither contraction nor relaxation differed in the aorta or mesenteric arteries of all groups. PCR analysis showed decreased expression of contractile markers in pulmonary artery of Su/Hx versus Nx. The reduced responsiveness to vasoconstrictors and NO-mediated vasodilation in the pulmonary, but not systemic, vessels may be an underlying mechanism of severe PH in Su/Hx rats and appears to involve attenuation of the NO relaxation pathway and a switch of pulmonary VSM cells to a synthetic less reactive phenotype.
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Affiliation(s)
- Helen Christou
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Hannes Hudalla
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Zoe Michael
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Evgenia J Filatava
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Jun Li
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Minglin Zhu
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Jose S Possomato-Vieira
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Carlos Dias-Junior
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Stella Kourembanas
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
| | - Raouf A Khalil
- Department of Pediatric Newborn Medicine (H.C., H.H., Z.M., E.J.F., S.K.), and Division of Vascular and Endovascular Surgery (J.L., M.Z., J.S.P.-V., C.D.-J., R.A.K.), Brigham and Women's Hospital, and Division of Newborn Medicine, Children's Hospital (H.C., S.K.), Harvard Medical School, Boston, Massachusetts; and Department of Neonatology, Children's University Hospital, Heidelberg, Germany (H.H.)
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24
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Abstract
Respiratory disease is a significant problem worldwide, and it is a problem with increasing prevalence. Pathology in the upper airways and lung is very difficult to diagnose and treat, as response to disease is often heterogeneous across patients. Computational models have long been used to help understand respiratory function, and these models have evolved alongside increases in the resolution of medical imaging and increased capability of functional imaging, advances in biological knowledge, mathematical techniques and computational power. The benefits of increasingly complex and realistic geometric and biophysical models of the respiratory system are that they are able to capture heterogeneity in patient response to disease and predict emergent function across spatial scales from the delicate alveolar structures to the whole organ level. However, with increasing complexity, models become harder to solve and in some cases harder to validate, which can reduce their impact clinically. Here, we review the evolution of complexity in computational models of the respiratory system, including successes in translation of models into the clinical arena. We also highlight major challenges in modelling the respiratory system, while making use of the evolving functional data that are available for model parameterisation and testing.
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Affiliation(s)
- Alys R Clark
- 1 Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Haribalan Kumar
- 1 Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Kelly Burrowes
- 2 Department of Chemical and Materials Engineering, The University of Auckland, Auckland, New Zealand
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25
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Jain P, Rao S, Macdonald P, Kotlyar E, Jabbour A, Hayward C, Keogh A. Diagnostic Performance of Pulmonary Capacitance at Rest and During Exercise in Idiopathic Pulmonary Arterial Hypertension. Heart Lung Circ 2017; 28:289-294. [PMID: 29150159 DOI: 10.1016/j.hlc.2017.10.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/24/2017] [Accepted: 10/29/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Reliable markers of early disease are needed in pulmonary arterial hypertension (PAH). As measures of the contribution of abnormal vascular compliance to overall vascular resistance, resting and exercise pulmonary capacitance-defined as the stroke volume divided by the change in pulmonary pulse pressure-may be sensitive markers of early disease. METHODS We examined all patients in our pulmonary hypertension database with idiopathic PAH, who had undergone rest and exercise right heart catheterisation in one sitting. Standard haemodynamic measurements were obtained, including pulmonary capacitance. These results were compared to age- and sex-matched normal controls. RESULTS We analysed 27 right heart catheterisations in idiopathic PAH patients and 23 in controls. Mean pulmonary artery pressure (MPAP), mean pulmonary capillary wedge pressure (mPCWP), pulmonary vascular resistance (PVR) and right ventricular stroke work index (RVSWI) were significantly higher at baseline in diseased patients, while Cardiac Index (CI) and pulmonary capacitance were significantly lower. MPAP, mPCWP, cardiac index and RVSWI increased significantly in both groups with exercise. Pulmonary capacitance decreased significantly in both groups. Pulmonary vascular resistance decreased with exercise in the control group only. Capacitance and PVR were inversely correlated at rest (time-constant of 0.79s) and with exercise (time-constant of 0.56s). The receiver operating characteristic (ROC) curve for capacitance as a diagnostic marker demonstrated an AUC of 0.96 at rest and 0.95 with exercise. CONCLUSIONS In idiopathic pulmonary arterial hypertension (IPAH) there is a reduction in pulmonary capacitance at baseline and left-shift of the inverse capacitance-PVR relationship with exercise. Both resting and exercise pulmonary capacitance have potential as diagnostic markers in early disease.
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Affiliation(s)
- Pankaj Jain
- St Vincent's Hospital, Sydney, NSW, Australia.
| | - Sriram Rao
- St Vincent's Hospital, Sydney, NSW, Australia
| | | | | | | | | | - Anne Keogh
- St Vincent's Hospital, Sydney, NSW, Australia
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26
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Dabral S, Pullamsetti SS. Vascular Stiffness and Mechanotransduction: Back in the Limelight. Am J Respir Crit Care Med 2017; 196:527-530. [DOI: 10.1164/rccm.201611-2254le] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Swati Dabral
- Max Planck Institute for Heart and Lung ResearchBad Nauheim, Germanyand
| | - Soni Savai Pullamsetti
- Max Planck Institute for Heart and Lung ResearchBad Nauheim, Germanyand
- Justus-Liebig UniversityGiessen, Germany
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27
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Acosta S, Puelz C, Rivière B, Penny DJ, Brady KM, Rusin CG. Cardiovascular mechanics in the early stages of pulmonary hypertension: a computational study. Biomech Model Mechanobiol 2017; 16:2093-2112. [PMID: 28733923 DOI: 10.1007/s10237-017-0940-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 07/12/2017] [Indexed: 01/12/2023]
Abstract
We formulate and study a new mathematical model of pulmonary hypertension. Based on principles of fluid and elastic dynamics, we introduce a model that quantifies the stiffening of pulmonary vasculature (arteries and arterioles) to reproduce the hemodynamics of the pulmonary system, including physiologically consistent dependence between compliance and resistance. This pulmonary model is embedded in a closed-loop network of the major vessels in the body, approximated as one-dimensional elastic tubes, and zero-dimensional models for the heart and other organs. Increasingly severe pulmonary hypertension is modeled in the context of two extreme scenarios: (1) no cardiac compensation and (2) compensation to achieve constant cardiac output. Simulations from the computational model are used to estimate cardiac workload, as well as pressure and flow traces at several locations. We also quantify the sensitivity of several diagnostic indicators to the progression of pulmonary arterial stiffening. Simulation results indicate that pulmonary pulse pressure, pulmonary vascular compliance, pulmonary RC time, luminal distensibility of the pulmonary artery, and pulmonary vascular impedance are much better suited to detect the early stages of pulmonary hypertension than mean pulmonary arterial pressure and pulmonary vascular resistance, which are conventionally employed as diagnostic indicators for this disease.
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Affiliation(s)
- Sebastián Acosta
- Department of Pediatrics-Cardiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA.
| | - Charles Puelz
- Department of Computational and Applied Mathematics, Rice University, Houston, TX, USA
| | - Béatrice Rivière
- Department of Computational and Applied Mathematics, Rice University, Houston, TX, USA
| | - Daniel J Penny
- Department of Pediatrics-Cardiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Ken M Brady
- Department of Anesthesiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Craig G Rusin
- Department of Pediatrics-Cardiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
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28
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Mookhoek A, Krishnan K, Chitsaz S, Kuang H, Ge L, Schoof PH, Bogers AJ, Takkenberg JJ, Tseng EE. Biomechanics of Failed Pulmonary Autografts Compared to Native Aortic Roots. Ann Thorac Surg 2017; 103:1482-1488. [DOI: 10.1016/j.athoracsur.2016.08.061] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 08/08/2016] [Accepted: 08/15/2016] [Indexed: 11/29/2022]
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29
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Rahman A, Zhou YQ, Yee Y, Dazai J, Cahill LS, Kingdom J, Macgowan CK, Sled JG. Ultrasound detection of altered placental vascular morphology based on hemodynamic pulse wave reflection. Am J Physiol Heart Circ Physiol 2017; 312:H1021-H1029. [PMID: 28364018 DOI: 10.1152/ajpheart.00791.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/16/2017] [Accepted: 03/28/2017] [Indexed: 11/22/2022]
Abstract
Abnormally pulsatile umbilical artery (UA) Doppler ultrasound velocity waveforms are a hallmark of severe or early onset placental-mediated intrauterine growth restriction (IUGR), whereas milder late onset IUGR pregnancies typically have normal UA pulsatility. The diagnostic utility of these waveforms to detect placental pathology is thus limited and hampered by factors outside of the placental circulation, including fetal cardiac output. In view of these limitations, we hypothesized that these Doppler waveforms could be more clearly understood as a reflection phenomenon and that a reflected pulse pressure wave is present in the UA that originates from the placenta and propagates backward along the UA. To investigate this, we developed a new ultrasound approach to isolate that portion of the UA Doppler waveform that arises from a pulse pressure wave propagating backward along the UA. Ultrasound measurements of UA lumen diameter and flow waveforms were used to decompose the observed flow waveform into its forward and reflected components. Evaluation of CD1 and C57BL/6 mice at embryonic day (E)15.5 and E17.5 demonstrated that the reflected waveforms diverged between the strains at E17.5, mirroring known changes in the fractal geometry of fetoplacental arteries at these ages. These experiments demonstrate the feasibility of noninvasively measuring wave reflections that originate from the fetoplacental circulation. The observed reflections were consistent with theoretical predictions based on the area ratio of parent to daughters at bifurcations in fetoplacental arteries suggesting that this approach could be used in the diagnosis of fetoplacental vascular pathology that is prevalent in human IUGR. Given that the proposed measurements represent a subset of those currently used in human fetal surveillance, the adaptation of this technology could extend the diagnostic utility of Doppler ultrasound in the detection of placental vascular pathologies that cause IUGR.NEW & NOTEWORTHY Here, we describe a novel approach to noninvasively detect microvascular changes in the fetoplacental circulation using ultrasound. The technique is based on detecting reflection pulse pressure waves that travel along the umbilical artery. Using a proof-of-principle study, we demonstrate the feasibility of the technique in two strains of experimental mice.
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Affiliation(s)
- Anum Rahman
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Yu-Qing Zhou
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Yohan Yee
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Jun Dazai
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Lindsay S Cahill
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada
| | - John Kingdom
- Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada.,Mount Sinai Hospital, Toronto, Ontario, Canada; and
| | - Christopher K Macgowan
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - John G Sled
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada; .,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada.,Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
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30
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Neary JM, Brown RD, Holt TN, Stenmark KR, Enns RM, Thomas MG, Garry FB. Static and dynamic components of right ventricular afterload are negatively associated with calf survival at high altitude1. J Anim Sci 2016; 94:4172-4178. [DOI: 10.2527/jas.2016-0652] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J. M. Neary
- Department of Animal and Food Sciences, College of Agricultural Sciences and Natural Resources, Texas Tech University, Lubbock 79409-2141
| | - R. D. Brown
- Division of Pediatric Critical Care, School of Medicine, University of Colorado Denver, Aurora 80045
| | - T. N. Holt
- Integrated Livestock Management, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 1678 Campus Delivery, Fort Collins 80523-1678
| | - K. R. Stenmark
- Division of Pediatric Critical Care, School of Medicine, University of Colorado Denver, Aurora 80045
| | - R. M. Enns
- Department of Animal Sciences, The College of Agricultural Sciences, Colorado State University, Fort Collins 80523-1171
| | - M. G. Thomas
- Department of Animal Sciences, The College of Agricultural Sciences, Colorado State University, Fort Collins 80523-1171
| | - F. B. Garry
- Integrated Livestock Management, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 1678 Campus Delivery, Fort Collins 80523-1678
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31
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Mookhoek A, Krishnan K, Chitsaz S, Kuang H, Ge L, Schoof PH, Bogers AJJC, Takkenberg JJM, Tseng EE. Biomechanics of Failed Pulmonary Autografts Compared With Normal Pulmonary Roots. Ann Thorac Surg 2016; 102:1996-2002. [PMID: 27457832 DOI: 10.1016/j.athoracsur.2016.05.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 04/27/2016] [Accepted: 05/02/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Progressive dilatation of pulmonary autografts after the Ross operation may reflect inadequate remodeling of the native pulmonary root to adapt to systemic circulation. Understanding the biomechanics of autograft root dilatation may aid designing strategies to prevent dilatation. We have previously characterized normal human pulmonary root material properties; however, the mechanical properties of failed autografts are unknown. In this study, failed autograft roots explanted during reoperation were acquired, and their material properties were determined. METHODS Failed pulmonary autograft specimens were obtained from patients undergoing reoperation after the Ross operation. Fresh human native pulmonary roots were obtained from the transplant donor network as controls. Biaxial stretch testing was performed to determine tissue mechanical properties. Tissue stiffness was determined at patient-specific physiologic stresses at pulmonary pressures. RESULTS Nonlinear stress-strain response was present in both failed autografts and normal pulmonary roots. Explanted pulmonary autografts were less stiff than were their native pulmonary root counterparts at 8 mm Hg (134 ± 42 vs 175 ± 49 kPa, respectively) (p = 0.086) and 25 mm Hg (369 ± 105 vs 919 ± 353 kPa, respectively) (p = 0.006). Autograft wall stiffness at both 8 and 25 mm Hg was not correlated with age at the Ross procedure (p = 0.898 and p = 0.813, respectively) or with time in the systemic circulation (p = 0.609 and p = 0.702, respectively). CONCLUSIONS Failed pulmonary autografts retained nonlinear response to mechanical loading typical of healthy human arterial tissue. Remodeling increased wall thickness but decreased wall stiffness in failed autografts. Increased compliance may explain progressive autograft root dilatation in autograft failures.
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Affiliation(s)
- Aart Mookhoek
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Kapil Krishnan
- Department of Surgery, University of California San Francisco Medical Center and San Francisco Veterans Affairs Medical Center, San Francisco, California
| | - Sam Chitsaz
- Division of Cardiology, Department of Medicine, University of Texas at Houston, Houston, Texas
| | - Heide Kuang
- Department of Surgery, University of California San Francisco Medical Center and San Francisco Veterans Affairs Medical Center, San Francisco, California
| | - Liang Ge
- Department of Surgery, University of California San Francisco Medical Center and San Francisco Veterans Affairs Medical Center, San Francisco, California
| | - Paul H Schoof
- Department of Pediatric Cardiothoracic Surgery, Utrecht University Medical Center, Utrecht, The Netherlands
| | - Ad J J C Bogers
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Johanna J M Takkenberg
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Elaine E Tseng
- Department of Surgery, University of California San Francisco Medical Center and San Francisco Veterans Affairs Medical Center, San Francisco, California.
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32
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Pulmonary Arterial Stiffness: Toward a New Paradigm in Pulmonary Arterial Hypertension Pathophysiology and Assessment. Curr Hypertens Rep 2016; 18:4. [PMID: 26733189 DOI: 10.1007/s11906-015-0609-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Stiffening of the pulmonary arterial bed with the subsequent increased load on the right ventricle is a paramount feature of pulmonary hypertension (PH). The pathophysiology of vascular stiffening is a complex and self-reinforcing function of extracellular matrix remodeling, driven by recruitment of circulating inflammatory cells and their interactions with resident vascular cells, and mechanotransduction of altered hemodynamic forces throughout the ventricular-vascular axis. New approaches to understanding the cell and molecular determinants of the pathophysiology combine novel biopolymer substrates, controlled flow conditions, and defined cell types to recapitulate the biomechanical environment in vitro. Simultaneously, advances are occurring to assess novel parameters of stiffness in vivo. In this comprehensive state-of-art review, we describe clinical hemodynamic markers, together with the newest translational echocardiographic and cardiac magnetic resonance imaging methods, to assess vascular stiffness and ventricular-vascular coupling. Finally, fluid-tissue interactions appear to offer a novel route of investigating the mechanotransduction processes and disease progression.
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33
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Huveneers S, Daemen MJAP, Hordijk PL. Between Rho(k) and a hard place: the relation between vessel wall stiffness, endothelial contractility, and cardiovascular disease. Circ Res 2015; 116:895-908. [PMID: 25722443 DOI: 10.1161/circresaha.116.305720] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Vascular stiffness is a mechanical property of the vessel wall that affects blood pressure, permeability, and inflammation. As a result, vascular stiffness is a key driver of (chronic) human disorders, including pulmonary arterial hypertension, kidney disease, and atherosclerosis. Responses of the endothelium to stiffening involve integration of mechanical cues from various sources, including the extracellular matrix, smooth muscle cells, and the forces that derive from shear stress of blood. This response in turn affects endothelial cell contractility, which is an important property that regulates endothelial stiffness, permeability, and leukocyte-vessel wall interactions. Moreover, endothelial stiffening reduces nitric oxide production, which promotes smooth muscle cell contraction and vasoconstriction. In fact, vessel wall stiffening, and microcirculatory endothelial dysfunction, precedes hypertension and thus underlies the development of vascular disease. Here, we review the cross talk among vessel wall stiffening, endothelial contractility, and vascular disease, which is controlled by Rho-driven actomyosin contractility and cellular mechanotransduction. In addition to discussing the various inputs and relevant molecular events in the endothelium, we address which actomyosin-regulated changes at cell adhesion complexes are genetically associated with human cardiovascular disease. Finally, we discuss recent findings that broaden therapeutic options for targeting this important mechanical signaling pathway in vascular pathogenesis.
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Affiliation(s)
- Stephan Huveneers
- From the Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Swammerdam Institute for Life Sciences (S.H., P.L.H.) and Department of Pathology (M.J.A.P.D.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Mat J A P Daemen
- From the Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Swammerdam Institute for Life Sciences (S.H., P.L.H.) and Department of Pathology (M.J.A.P.D.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Peter L Hordijk
- From the Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Swammerdam Institute for Life Sciences (S.H., P.L.H.) and Department of Pathology (M.J.A.P.D.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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34
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Tan W, Madhavan K, Hunter KS, Park D, Stenmark KR. Vascular stiffening in pulmonary hypertension: cause or consequence? (2013 Grover Conference series). Pulm Circ 2014; 4:560-80. [PMID: 25610594 PMCID: PMC4278618 DOI: 10.1086/677370] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 05/27/2014] [Indexed: 12/24/2022] Open
Abstract
Recent studies have indicated that systemic arterial stiffening is a precursor to hypertension and that hypertension, in turn, can perpetuate arterial stiffening. Pulmonary artery (PA) stiffening is also well documented to occur in pulmonary hypertension (PH), and there is evidence that pulmonary vascular stiffness (PVS) may be a better predictor of outcome than pulmonary vascular resistance (PVR). We have hypothesized that the decreased flow-damping function of elastic PAs in PH likely initiates and/or perpetuates dysfunction of pulmonary microvasculature. Recent studies have shown that large-vessel stiffening increases flow pulsatility in the distal pulmonary vasculature, leading to endothelial dysfunction within a proinflammatory, vasoconstricting, and profibrogenic environment. The intricate role of stiffening-stimulated high pulsatile flow in endothelial cell dysfunction includes stepwise molecular events underlying PA hypertrophy, inflammation, endothelial-mesenchymal transition, and fibrosis. In addition to contributing to microenvironmental alterations of the distal vasculature, disordered proximal-distal PA coupling likely also plays a role in increasing ventricular afterload, ultimately causing right ventricle (RV) dysfunction and death. Current therapeutic treatments do not provide a realistic approach to destiffening arteries and, thus, to potentially abrogating the effects of high pulsatile flow on the distal pulmonary vasculature or the increased work imposed by stiffening on the RV. Scrutinizing the effect of PA stiffening on high pulsatile flow-induced cellular and molecular changes, and vice versa, might lead to important new therapeutic options that abrogate PA remodeling and PH development. With a clear understanding that PA stiffening may contribute to the progression of PH to an irreversible state by contributing to chronic microvascular damage in lungs, future studies should be aimed first at defining the underlying mechanisms leading to PA stiffening and then at improved treatment approaches based on these findings.
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Affiliation(s)
- Wei Tan
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA
- Cardiovascular Pulmonary Research Laboratories, University of Colorado Denver, Aurora, Colorado, USA
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Krishna Madhavan
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA
- Department of Bioengineering, University of Colorado Denver, Aurora, Colorado, USA
| | - Kendall S. Hunter
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA
- Department of Bioengineering, University of Colorado Denver, Aurora, Colorado, USA
| | - Daewon Park
- Department of Bioengineering, University of Colorado Denver, Aurora, Colorado, USA
| | - Kurt R. Stenmark
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA
- Cardiovascular Pulmonary Research Laboratories, University of Colorado Denver, Aurora, Colorado, USA
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35
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Pugliese SC, Poth JM, Fini MA, Olschewski A, El Kasmi KC, Stenmark KR. The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes. Am J Physiol Lung Cell Mol Physiol 2014; 308:L229-52. [PMID: 25416383 DOI: 10.1152/ajplung.00238.2014] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hypoxic pulmonary hypertension (PH) comprises a heterogeneous group of diseases sharing the common feature of chronic hypoxia-induced pulmonary vascular remodeling. The disease is usually characterized by mild to moderate pulmonary vascular remodeling that is largely thought to be reversible compared with the progressive irreversible disease seen in World Health Organization (WHO) group I disease. However, in these patients, the presence of PH significantly worsens morbidity and mortality. In addition, a small subset of patients with hypoxic PH develop "out-of-proportion" severe pulmonary hypertension characterized by pulmonary vascular remodeling that is irreversible and similar to that in WHO group I disease. In all cases of hypoxia-related vascular remodeling and PH, inflammation, particularly persistent inflammation, is thought to play a role. This review focuses on the effects of hypoxia on pulmonary vascular cells and the signaling pathways involved in the initiation and perpetuation of vascular inflammation, especially as they relate to vascular remodeling and transition to chronic irreversible PH. We hypothesize that the combination of hypoxia and local tissue factors/cytokines ("second hit") antagonizes tissue homeostatic cellular interactions between mesenchymal cells (fibroblasts and/or smooth muscle cells) and macrophages and arrests these cells in an epigenetically locked and permanently activated proremodeling and proinflammatory phenotype. This aberrant cellular cross-talk between mesenchymal cells and macrophages promotes transition to chronic nonresolving inflammation and vascular remodeling, perpetuating PH. A better understanding of these signaling pathways may lead to the development of specific therapeutic targets, as none are currently available for WHO group III disease.
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Affiliation(s)
- Steven C Pugliese
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado;
| | - Jens M Poth
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Mehdi A Fini
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; and
| | - Karim C El Kasmi
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, University of Colorado Denver, School of Medicine, Anschutz Medical Campus, Aurora, Colorado
| | - Kurt R Stenmark
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
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Adatia I, Haworth SG, Wegner M, Barst RJ, Ivy D, Stenmark KR, Karkowsky A, Rosenzweig E, Aguilar C. Clinical trials in neonates and children: Report of the pulmonary hypertension academic research consortium pediatric advisory committee. Pulm Circ 2013; 3:252-66. [PMID: 23662203 PMCID: PMC3641736 DOI: 10.4103/2045-8932.109931] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Drug trials in neonates and children with pulmonary hypertensive vascular disease pose unique but not insurmountable challenges. Childhood is defined by growth and development. Both may influence disease and outcomes of drug trials. The developing pulmonary vascular bed and airways may be subjected to maldevelopment, maladaptation, growth arrest, or dysregulation that influence the disease phenotype. Drug therapy is influenced by developmental changes in renal and hepatic blood flow, as well as in metabolic systems such as cytochrome P450. Drugs may affect children differently from adults, with different clearance, therapeutic levels and toxicities. Toxicity may not be manifested until the child reaches physical, endocrine and neurodevelopmental maturity. Adverse effects may be revealed in the next generation, should the development of ova or spermatozoa be affected. Consideration of safe, age-appropriate tablets and liquid formulations is an obvious but often neglected prerequisite to any pediatric drug trial. In designing a clinical trial, precise phenotyping and genotyping of disease is required to ensure appropriate and accurate inclusion and exclusion criteria. We need to explore physiologically based pharmacokinetic modeling and simulations together with statistical techniques to reduce sample size requirements. Clinical endpoints such as exercise capacity, using traditional classifications and testing cannot be applied routinely to children. Many lack the necessary neurodevelopmental skills and equipment may not be appropriate for use in children. Selection of endpoints appropriate to encompass the developmental spectrum from neonate to adolescent is particularly challenging. One possible solution is the development of composite outcome scores that include age and a developmentally specific functional classification, growth and development scores, exercise data, biomarkers and hemodynamics with repeated evaluation throughout the period of growth and development. In addition, although potentially costly, we recommend long-term continuation of blinded dose ranging after completion of the short-term, double-blind, placebo-controlled trial for side-effect surveillance, which should include neurodevelopmental and peripubertal monitoring. The search for robust evidence to guide safe therapy of children and neonates with pulmonary hypertensive vascular disease is a crucial and necessary goal.
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Affiliation(s)
- Ian Adatia
- Stollery Children's Hospital, University of Alberta, Edmonton, Canada
| | | | | | | | - Dunbar Ivy
- Children's Hospital of Colorado, University of Colorado, Denver, Colorado, USA
| | - Kurt R. Stenmark
- Children's Hospital of Colorado, University of Colorado, Denver, Colorado, USA
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