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Fischer KS, Henn D, Zhao ET, Sivaraj D, Litmanovich B, Hahn WW, Hostler AC, Mojadidi SM, Gonzalez J, Knochel AB, Mora Pinos MG, Holley J, Kussie H, Granoski M, Yasmeh JP, Kneser U, Chen K, Gurtner GC. Elevated Shear Stress Modulates Heterogenous Cellular Subpopulations to Induce Vascular Remodeling. Tissue Eng Part A 2024. [PMID: 38753711 DOI: 10.1089/ten.tea.2023.0362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024] Open
Abstract
Rationale: Elevated shear stress (ESS) induces vascular remodeling in veins exposed to arterial blood flow, which can lead to arteriovenous (AV) fistula failure. The molecular mechanisms driving remodeling have not been comprehensively examined with a single-cell resolution before. Objective: Using an in vivo animal mode, single-cell RNA sequencing, and histopathology, we precisely manipulate blood flow to comprehensively characterize all cell subpopulations important during vascular remodeling. Methods: AV loops were created in saphenous vessels of rats using a contralateral saphenous vein interposition graft to promote ESS. Saphenous veins with no elevated shear stress (NSS) were anastomosed as controls. Findings: ESS promoted transcriptional homogeneity, and NSS promoted considerable heterogeneity. Specifically, ESS endothelial cells (ECs) showed a more homogeneous transcriptional response promoting angiogenesis and upregulating endothelial-to-mesenchymal transition inhibiting genes (Klf2). NSS ECs upregulated antiproliferation genes such as Cav1, Cst3, and Btg1. In macrophages, ESS promoted a large homogeneous subpopulation, creating a mechanically activated, proinflammatory and thus proangiogenic myeloid phenotype, whereas NSS myeloid cells expressed the anti-inflammatory and antiangiogenetic marker Mrc1. Conclusion: ESS activates unified gene expression profiles to induce adaption of the vessel wall to hemodynamic alterations. Targeted depletion of the identified cellular subpopulations may lead to novel therapies to prevent excessive venous remodeling, intimal hyperplasia, and AV fistula failure.
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Affiliation(s)
- Katharina S Fischer
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University, Stanford, California, USA
- Department of Plastic and Reconstructive Surgery and Hand surgery, BG Trauma Clinic Ludwigshafen, University of Heidelberg, Heidelberg, Germany
| | - Dominic Henn
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University, Stanford, California, USA
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Eric T Zhao
- Department of Chemical Engineering, Stanford University, Stanford, California, USA
| | - Dharshan Sivaraj
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University, Stanford, California, USA
| | - Ben Litmanovich
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | - William W Hahn
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | - Andrew C Hostler
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | | | - Javier Gonzalez
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | - Amelia B Knochel
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | | | - Jared Holley
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | - Hudson Kussie
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University, Stanford, California, USA
| | - Maia Granoski
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
| | | | - Ulrich Kneser
- Department of Plastic and Reconstructive Surgery and Hand surgery, BG Trauma Clinic Ludwigshafen, University of Heidelberg, Heidelberg, Germany
| | - Kellen Chen
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University, Stanford, California, USA
| | - Geoffrey C Gurtner
- Department of Surgery, University of Arizona, Tucson, Arizona, USA
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University, Stanford, California, USA
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Otunla AA, Shanmugarajah K, Davies AH, Lucia Madariaga M, Shalhoub J. The Biological Parallels Between Atherosclerosis and Cardiac Allograft Vasculopathy: Implications for Solid Organ Chronic Rejection. Cardiol Rev 2024; 32:2-11. [PMID: 38051983 DOI: 10.1097/crd.0000000000000437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Atherosclerosis and solid organ chronic rejection are pervasive chronic disease states that account for significant morbidity and mortality in developed countries. Recently, a series of shared molecular pathways have emerged, revealing biological parallels from early stages of development up to the advanced forms of pathology. These shared mechanistic processes are inflammatory in nature, reflecting the importance of inflammation in both disorders. Vascular inflammation triggers endothelial dysfunction and disease initiation through aberrant vasomotor control and shared patterns of endothelial activation. Endothelial dysfunction leads to the recruitment of immune cells and the perpetuation of the inflammatory response. This drives lesion formation through the release of key cytokines such as IFN-y, TNF-alpha, and IL-2. Continued interplay between the adaptive and innate immune response (represented by T lymphocytes and macrophages, respectively) promotes lesion instability and thrombotic complications; hallmarks of advanced disease in both atherosclerosis and solid organ chronic rejection. The aim of this study is to identify areas of overlap between atherosclerosis and chronic rejection. We then discuss new approaches to improve current understanding of the pathophysiology of both disorders, and eventually design novel therapeutics.
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Affiliation(s)
- Afolarin A Otunla
- From the Medical Sciences Division, University of Oxford, Oxford, United Kingdom
| | | | - Alun H Davies
- Section of Vascular Surgery, Department of Surgery & Cancer, Imperial College London, London, United Kingdom
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London, United Kingdom
| | | | - Joseph Shalhoub
- Section of Vascular Surgery, Department of Surgery & Cancer, Imperial College London, London, United Kingdom
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London, United Kingdom
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Barth RF, Maximilian Buja L, Cao L, Brodsky SV. An Obesity Paradox: Increased Body Mass Index Is Associated with Decreased Aortic Atherosclerosis. Curr Hypertens Rep 2018; 19:55. [PMID: 28593612 DOI: 10.1007/s11906-017-0753-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Brodsky et al. (Cardiovasc Pathol 25(6), 515-520, 2016) recently have reported that there was an unexpected and highly significant inverse correlation between body mass index (BMI) and atherosclerosis of the aortas of morbidly obese decedents (BMI >40 kg/m2). In a series of 304 decedents, 65 of whom were morbidly obese, minimal or no atherosclerosis was seen in 46 of them (70%) versus 20 (30%) who had severe atherosclerosis (P = 0.008). This obesity paradox was unexpected and raises important questions about the etiology and pathogenesis of atherosclerosis, which will be the subject of this commentary. The concept of healthy versus unhealthy adiposity may in part provide an explanation for the "obesity paradox." Another factor that will be considered is the possible role of adipokines and their genetic determinants that may significantly reduce the risk of developing aortic atherosclerosis in morbidly obese individuals. Considering the marked variability in the pattern and extent of atherosclerosis of the aorta, hemodynamic factors and endothelial cell shear stress may be the most important determinants that might explain the obesity paradox that we have observed. Finally, the possible role of gut microbiota and inflammation as factors in the etiopathogenesis of atherosclerosis will be considered, but their importance is less clear than that of hemodynamic factors. We conclude with the remarkable finding that a 5300-year-old, well-preserved mummy of the "Iceman," Ötzi had atherosclerotic disease of a number of major arteries and the interesting questions that this raises.
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Affiliation(s)
- Rolf F Barth
- Department of Pathology, The Ohio State University, 4132 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210, USA.
| | - L Maximilian Buja
- McGovern Medical School, Department of Pathology and Laboratory Medicine, University of Texas, 6431 Fannin St. MSB2.276, Houston, TX, 77030, USA
| | - Lei Cao
- Department of Cancer Biology and Genetics, The Ohio State University, 910 Biological Research Tower, 460 W. 12th Ave, Columbus, OH, 43210, USA
| | - Sergey V Brodsky
- Department of Pathology, The Ohio State University, B078 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210, USA
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Wang Y, Qiu J, Luo S, Xie X, Zheng Y, Zhang K, Ye Z, Liu W, Gregersen H, Wang G. High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis. Regen Biomater 2016; 3:257-67. [PMID: 27482467 PMCID: PMC4966293 DOI: 10.1093/rb/rbw021] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/15/2016] [Accepted: 05/19/2016] [Indexed: 12/12/2022] Open
Abstract
Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions.
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Affiliation(s)
- Yi Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Juhui Qiu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Shisui Luo
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Xiang Xie
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Yiming Zheng
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Kang Zhang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Zhiyi Ye
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Wanqian Liu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Hans Gregersen
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
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Co-localization of Disturbed Flow Patterns and Occlusive Cardiac Allograft Vasculopathy Lesion Formation in Heart Transplant Patients. Cardiovasc Eng Technol 2014; 6:25-35. [DOI: 10.1007/s13239-014-0198-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 10/21/2014] [Indexed: 10/24/2022]
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6
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Wellnhofer E, Stypmann J, Bara CL, Stadlbauer T, Heidt MC, Kreider-Stempfle HU, Sohn HY, Zeh W, Comberg T, Eckert S, Dengler T, Ensminger SM, Hiemann NE. Angiographic assessment of cardiac allograft vasculopathy: results of a Consensus Conference of the Task Force for Thoracic Organ Transplantation of the German Cardiac Society. Transpl Int 2010; 23:1094-104. [DOI: 10.1111/j.1432-2277.2010.01096.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Hu ZY, Chen SL, Zhang JJ, Shan SJ, Liu ZZ, Ye F, Kan J, Xu HM, Nguyen K, Kwan T, Nguyen T, Hoang T. Distribution and magnitude of shear stress after coronary bifurcation lesions stenting with the classical crush technique: a new predictor for in-stent restenosis. J Interv Cardiol 2010; 23:330-40. [PMID: 20642479 DOI: 10.1111/j.1540-8183.2010.00571.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Wall shear stress (SS) plays an important role in the initiation and proliferation of coronary atherosclerosis, especially for bifurcations. Stenting in the coronary artery will cause many different changes in velocity, flow, cross-sectional area, and especially the wall SS. However, it is still unknown how much wall SS distribution varies with stenting in coronary bifurcation. OBJECTIVE The purpose of this study was to investigate the magnitude and distribution of wall SS after the classical crush stenting for bifurcation lesions. METHODS Eleven patients with true coronary bifurcation stenting by the classical crush technique were included. We studied the difference of wall SS between restenosis and nonrestenosis groups in these patients. The differences in SS between preprocedure and postprocedure, as well as between immediately postprocedure and after an 8-month follow-up, were also analyzed. Diameter stenosis or minimal lumen diameter were measured by quantitative coronary analysis. The commercial CD STAR-CCM+ was used to calculate the SS. RESULTS At baseline, the SS in all the segments of all patients was high. The baseline SS of the restenosis group was 50% lower than the nonrestenosis group. Immediately after percutaneous coronary intervention (PCI), the SS in both areas decreased; however, the SS of the nonrestenosis group decreased to its lowest level possible while the SS of the restenosis group decreased moderately. Eight months later, the SS of all the segments of the nonrestenosis group remained persistently low at the same level of right after PCI. In contrary, the SS in the restenosis group returned to near its baseline level. CONCLUSION From our study, after a 2-stent crush technique using drug-eluting stents (DES), the degree of SS reduction appears to predict in-stent restenosis (ISR). A SS decrease to its lowest level and remaining homogenously low is a prime condition to prevent ISR. A baseline low SS, which decreases minimally after PCI and recovers to around its baseline level, appears to be the setting for restenosis. These conditions can be evaluated as predictors of lesions that may need surveillance angiography and proper IVUS evaluation to prevent future in-stent restenosis.
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Affiliation(s)
- Zuo-Ying Hu
- Cardiological Department, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
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Coronary Artery WSS Profiling Using a Geometry Reconstruction Based on Biplane Angiography. Ann Biomed Eng 2009; 37:682-91. [DOI: 10.1007/s10439-009-9656-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Accepted: 02/10/2009] [Indexed: 11/25/2022]
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9
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10
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Goubergrits L, Kertzscher U, Schöneberg B, Wellnhofer E, Petz C, Hege HC. CFD analysis in an anatomically realistic coronary artery model based on non-invasive 3D imaging: comparison of magnetic resonance imaging with computed tomography. Int J Cardiovasc Imaging 2007; 24:411-21. [DOI: 10.1007/s10554-007-9275-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Accepted: 10/10/2007] [Indexed: 12/01/2022]
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Hiemann NE, Wellnhofer E, Knosalla C, Lehmkuhl HB, Stein J, Hetzer R, Meyer R. Prognostic impact of microvasculopathy on survival after heart transplantation: evidence from 9713 endomyocardial biopsies. Circulation 2007; 116:1274-82. [PMID: 17709643 DOI: 10.1161/circulationaha.106.647149] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Epicardial vasculopathy has been shown to be associated with poor outcome after heart transplantation. We demonstrate that histologically proven stenotic microvasculopathy is a novel prognostic factor for long-term survival. METHODS AND RESULTS In 9713 biopsies harvested within the first posttransplantation year from 873 patients (83% male; mean age, 49.1+/-0.6 years), light microscopic evaluations (x200) were performed for microvasculopathy, defined as stenotic endothelial and/or medial disease. Prevalence of severe epicardial vasculopathy was defined by presence of > or = 75% luminal stenosis in coronary angiography (available in 611 of 873 patients), which was present in 118 of 611 patients (19%). For Kaplan-Meier analysis, we defined fatal cardiac events as lethal acute myocardial infarction, sudden cardiac death, and graft failure. Stenotic microvasculopathy was present in 379 of 873 patients (43%) and was due to medial (345/379; 91%) rather than endothelial disease (2/379; 1%) or a combination of both (31/379; 8%; P<0.001). Endothelial disease (median [95% CI], 12.07 [10.69 to 13.44] versus 12.73 years [10.16 to 15.30]; P=0.3329) and nonstenotic medial disease (12.44 [11.14 to 13.74] versus 12.43 years [10.51 to 14.35]; P=0.4047) did not decrease overall survival or time to fatal cardiac event. Stenotic microvasculopathy was associated with poor overall survival (10.90 [9.16 to 12.60] versus 13.40 years [11.79 to 15.07]; P=0.0374) and decreased freedom from fatal cardiac events (1, 5, 10 years, 95.6+/-1.4%, 86.9+/-2.3%, 75.5+/-3.1% versus 99.1+/-0.5%, 96.8+/-1.0%, 89.8+/-1.9%; P<0.0001). This finding was independent of epicardial transplant vasculopathy (P=0.0031). CONCLUSIONS Stenotic microvasculopathy is frequent in routinely processed biopsies and a new prognostic factor for long-term survival after heart transplantation.
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Affiliation(s)
- Nicola E Hiemann
- Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
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Segovia J, Gómez-Bueno M, Alonso-Pulpón L. Treatment of allograft vasculopathy in heart transplantation. Expert Opin Pharmacother 2006; 7:2369-83. [PMID: 17109612 DOI: 10.1517/14656566.7.17.2369] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cardiac allograft vasculopathy remains one of the main causes of morbidity and mortality after heart transplantation, although its impact is becoming somewhat smaller as prophylactic measures are implemented. Advances in the understanding of the molecular and cellular mechanisms involved in the genesis and development of cardiac allograft vasculopathy are opening ways for new diagnostic and therapeutic strategies. Successful prophylaxis of the early stages of the disease has been demonstrated with the use of newer immunosuppressive agents, such as sirolimus and everolimus, that will probably be included in future protocols. For most patients with established cardiac allograft vasculopathy, currently available revascularisation methods and retransplantation are not appropriate options. Antiproliferative agents could provide significant improvement in terms of symptom relief and prognosis, but their definite value must be proven in well-designed trials.
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Affiliation(s)
- Javier Segovia
- Unidad de Trasplante Cardiaco, Hospital Universitario Puerta de Hierro, C/S. Martín de Porres, 4, 28035 Madrid, Spain.
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Wellnhofer E, Goubergrits L, Kertzscher U, Affeld K. In-vivo coronary flow profiling based on biplane angiograms: influence of geometric simplifications on the three-dimensional reconstruction and wall shear stress calculation. Biomed Eng Online 2006; 5:39. [PMID: 16774680 PMCID: PMC1513234 DOI: 10.1186/1475-925x-5-39] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Accepted: 06/14/2006] [Indexed: 11/10/2022] Open
Abstract
Background Clinical studies suggest that local wall shear stress (WSS) patterns modulate the site and the progression of atherosclerotic lesions. Computational fluid dynamics (CFD) methods based on in-vivo three-dimensional vessel reconstructions have recently been shown to provide prognostically relevant WSS data. This approach is, however, complex and time-consuming. Methodological simplifications are desirable in porting this approach from bench to bedside. The impact of such simplifications on the accuracy of geometry and wall shear stress calculations has to be investigated. Methods We investigated the influence of two methods of lumen reconstruction, assuming circular versus elliptical cross-sections and using different resolutions for the cross-section reconstructions along the vessel axis. Three right coronary arteries were used, of which one represented a normal coronary artery, one with "obstructive", and one with "dilated" coronary atherosclerosis. The vessel volume reconstruction was performed with three-dimensional (3D) data from a previously validated 3D angiographic reconstruction of vessel cross-sections and vessel axis. Results The difference between the two vessel volumes calculated using the two evaluated methods is less than 1 %. The difference, of the calculated pressure loss, was between 2.5% and 8.5% for the evaluated methods. The distributions of the WSS histograms were nearly identical and strongly cross-correlated (0.91–0.95). The good agreement of the results was confirmed by a Chi-square test. Conclusion A simplified approach to the reconstruction of coronary vessel lumina, using circular cross-sections and a reduced axial resolution of about 0.8 mm along the vessel axis, yields sufficiently accurate calculations of WSS.
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Affiliation(s)
| | - Leonid Goubergrits
- Biofluid Mechanics Laboratory, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ulrich Kertzscher
- Biofluid Mechanics Laboratory, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Klaus Affeld
- Biofluid Mechanics Laboratory, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Atkinson C, Southwood M, Pitman R, Phillpotts C, Wallwork J, Goddard M. Angiogenesis occurs within the intimal proliferation that characterizes transplant coronary artery vasculopathy. J Heart Lung Transplant 2005; 24:551-8. [PMID: 15896752 DOI: 10.1016/j.healun.2004.03.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2004] [Revised: 03/01/2004] [Accepted: 03/16/2004] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND Vascular remodeling is central to the development of transplant coronary artery vasculopathy (CAV). For remodeling to occur, a sustained blood and nutrient supply is essential. Here we report on the presence of angiogenesis within the neointima of coronary arteries from cardiac transplant recipients. METHODS Coronary arteries from 57 cardiac transplant recipients with CAV were analyzed. Immunocytochemistry with antibodies raised against endothelial cells (CD31, CD34, and vWF), vascular smooth muscle cells (SmA), and activated endothelial cells (MHC 2, P-SEL, E-SEL, and VCAM-1) was performed. RESULTS A total of 89% of patients had significant angiogenesis. These vessels appeared as endothelial lined channels and were present in a concentric circumferential pattern within the mid portion of the neointima. These new vessels were present at an interface between an area of intimal hyperplasia and below an area of fibrous regeneration. These 2 distinct zones were present in 64% of the cases, and were clearly demonstrated with an elastic van Gieson (EVG) stain and are distinctly different from that seen in native atherosclerosis. Endothelial activation markers were strongly expressed by the endothelial cells lining new vessels, suggesting that they are functional and may aid in the recruitment of inflammatory cells. CONCLUSIONS These data suggest that angiogenesis is present within the intima of CAV lesions and may contribute to the continued obliteration of the vessel lumen. The vessels appear to originate in the intima and may represent the location of the donor endothelium before transplantation. Inhibition of endothelial damage may provide therapeutic options to prevent the progression of CAV.
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Affiliation(s)
- Carl Atkinson
- Pathology Department, Papworth Hospital NHS Trust, Papworth Everard, Cambridg, United Kingdom.
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Zhang W, Herrera C, Atluri SN, Kassab GS. Effect of surrounding tissue on vessel fluid and solid mechanics. J Biomech Eng 2005; 126:760-9. [PMID: 15796334 DOI: 10.1115/1.1824128] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
There is no doubt that atherosclerosis is one of the most important health problems in the Western Societies. It is well accepted that atherosclerosis is associated with abnormal stress and strain conditions. A compelling observation is that the epicardial arteries develop atherosclerosis while the intramural arteries do not. Atherosclerotic changes involving the epicardial portion of the coronary artery stop where the artery penetrates the myocardium. The objective of the present study is to understand the fluid and solid mechanical differences between the two types of vessels. A finite element analysis was employed to investigate the effect of external tissue contraction on the characteristics of pulsatile blood flow and the vessel wall stress distribution. The sequential coupling of fluid-solid interaction (FSI) revealed that the changes of flow velocity and wall shear stress, in response to cyclical external loading, appear less important than the circumferential stress and strain reduction in the vessel wall under the proposed boundary conditions. These results have important implications since high stresses and strains can induce growth, remodeling, and atherosclerosis; and hence we speculate that a reduction of stress and strain may be atheroprotective. The importance of FSI in deformable vessels with pulsatile flow is discussed and the fluid and solid mechanics differences between epicardial and intramural vessels are highlighted.
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Affiliation(s)
- Wei Zhang
- Department of Mechanical and Aerospace Engineering, University of California, 204 Rockwell Engineering Center, Irvine, CA 92657, USA
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