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Tran P, Lau C, Joshi M, Kuehl M, Maddock H, Banerjee P. Exploring Changes in Myocyte Structure, Contractility, and Energetics From Mechanical Unloading in Patients With Heart Failure Undergoing Ventricular Assist Device Implantation: A Systematic Review and Meta-Analysis. Heart Lung Circ 2024; 33:1097-1116. [PMID: 38704332 DOI: 10.1016/j.hlc.2024.01.039] [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: 09/17/2023] [Revised: 01/27/2024] [Accepted: 01/31/2024] [Indexed: 05/06/2024]
Abstract
AIMS Recent reports of myocardial recovery after mechanical unloading with left ventricular assist devices (LVADs) have challenged the prevailing notion that end-stage heart failure (HF) is irreversible. To improve our understanding of this phenomenon, we comprehensively analysed the structural, functional, and energetic changes in failing human cardiomyocytes after LVAD implantation. METHODS Based on a prospectively registered protocol (PROSPERO-CRD42022380214), 30 eligible studies were identified from 940 records with a pooled population of 648 patients predominantly with non-ischaemic cardiomyopathy. RESULTS LVAD led to a substantial regression in myocyte size similar to that of donor hearts (standardised mean difference, -1.29; p<0.001). The meta-regression analysis revealed that HF duration was a significant modifier on the changes in myocyte size. There were some suggestions of fibrosis reversal (-5.17%; p=0.009); however, this was insignificant after sensitivity analysis. Developed force did not improve in cardiac trabeculae (n=5 studies); however, non-physiological isometric contractions were tested. At the myocyte level (n=4 studies), contractile kinetics improved where the time-to-peak force reduced by 41.7%-50.7% and time to 50% relaxation fell by 47.4%-62.1% (p<0.05). Qualitatively, LVAD enhanced substrate utilisation and mitochondrial function (n=6 studies). Most studies were at a high risk of bias. CONCLUSION The regression of maladaptive hypertrophy, partial fibrosis reversal, and normalisation in metabolic pathways after LVAD may be a testament to the heart's remarkable plasticity, even in the advanced stages of HF. However, inconsistencies exist in force-generating capabilities. Using more physiological force-length work-loop assays, addressing the high risks of bias and clinical heterogeneity are crucial to better understand the phenomenon of reverse remodelling.
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Affiliation(s)
- Patrick Tran
- Centre for Health & Life Sciences, Coventry University, Coventry, UK; Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK.
| | - Clement Lau
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - Mithilesh Joshi
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK; Warwick Medical School, University of Warwick, Coventry, UK
| | - Michael Kuehl
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK; Warwick Medical School, University of Warwick, Coventry, UK
| | - Helen Maddock
- Centre for Health & Life Sciences, Coventry University, Coventry, UK
| | - Prithwish Banerjee
- Centre for Health & Life Sciences, Coventry University, Coventry, UK; Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK; Warwick Medical School, University of Warwick, Coventry, UK
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Kolesár DM, Kujal P, Mrázová I, Pokorný M, Škaroupková P, Sadowski J, Červenka L, Netuka I. Sex-Linked Differences in Cardiac Atrophy After Mechanical Unloading Induced by Heterotopic Heart Transplantation. Physiol Res 2024; 73:9-25. [PMID: 38466001 PMCID: PMC11019613 DOI: 10.33549/physiolres.935217] [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: 09/08/2023] [Accepted: 10/23/2023] [Indexed: 04/26/2024] Open
Abstract
No information is available about sex-related differences in unloading-induced cardiac atrophy. We aimed to compare the course of unloading-induced cardiac atrophy in intact (without gonadectomy) male and female rats, and in animals after gonadectomy, to obtain insight into the influence of sex hormones on this process. Heterotopic heart transplantation (HT((x)) was used as a model for heart unloading. Cardiac atrophy was assessed as the weight ratio of heterotopically transplanted heart weight (HW) to the native HW on days 7 and 14 after HTx in intact male and female rats. In separate experimental groups, gonadectomy was performed in male and female recipient animals 28 days before HT(x) and the course of cardiac atrophy was again evaluated on days 7 and 14 after HT(x). In intact male rats, HT(x) resulted in significantly greater decreases in whole HW when compared to intact female rats. The dynamics of the left ventricle (LV) and right ventricle (RV) atrophy after HT(x) was quite similar to that of whole hearts. Gonadectomy did not have any significant effect on the decreases in whole HW, LV, and RV weights, with similar results in male and female rats. Our results show that the development of unloading-induced cardiac atrophy is substantially reduced in female rats when compared to male rats. Since gonadectomy did not alter the course of cardiac atrophy after HTx, similarly in both male and female rats, we conclude that sex-linked differences in the development of unloading-induced cardiac atrophy are not caused by the activity of sex hormones.
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Affiliation(s)
- D M Kolesár
- Department of Cardiovascular Surgery, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
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3
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Cardiac fibroblasts and mechanosensation in heart development, health and disease. Nat Rev Cardiol 2022; 20:309-324. [PMID: 36376437 DOI: 10.1038/s41569-022-00799-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/04/2022] [Indexed: 11/16/2022]
Abstract
The term 'mechanosensation' describes the capacity of cells to translate mechanical stimuli into the coordinated regulation of intracellular signals, cellular function, gene expression and epigenetic programming. This capacity is related not only to the sensitivity of the cells to tissue motion, but also to the decryption of tissue geometric arrangement and mechanical properties. The cardiac stroma, composed of fibroblasts, has been historically considered a mechanically passive component of the heart. However, the latest research suggests that the mechanical functions of these cells are an active and necessary component of the developmental biology programme of the heart that is involved in myocardial growth and homeostasis, and a crucial determinant of cardiac repair and disease. In this Review, we discuss the general concept of cell mechanosensation and force generation as potent regulators in heart development and pathology, and describe the integration of mechanical and biohumoral pathways predisposing the heart to fibrosis and failure. Next, we address the use of 3D culture systems to integrate tissue mechanics to mimic cardiac remodelling. Finally, we highlight the potential of mechanotherapeutic strategies, including pharmacological treatment and device-mediated left ventricular unloading, to reverse remodelling in the failing heart.
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Tseliou E, Lavine KJ, Wever-Pinzon O, Topkara VK, Meyns B, Adachi I, Zimpfer D, Birks EJ, Burkhoff D, Drakos SG. Biology of myocardial recovery in advanced heart failure with long-term mechanical support. J Heart Lung Transplant 2022; 41:1309-1323. [PMID: 35965183 DOI: 10.1016/j.healun.2022.07.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/03/2022] [Accepted: 07/07/2022] [Indexed: 10/17/2022] Open
Abstract
Cardiac remodeling is an adaptive, compensatory biological process following an initial insult to the myocardium that gradually becomes maladaptive and causes clinical deterioration and chronic heart failure (HF). This biological process involves several pathophysiological adaptations at the genetic, molecular, cellular, and tissue levels. A growing body of clinical and translational investigations demonstrated that cardiac remodeling and chronic HF does not invariably result in a static, end-stage phenotype but can be at least partially reversed. One of the paradigms which shed some additional light on the breadth and limits of myocardial elasticity and plasticity is long term mechanical circulatory support (MCS) in advanced HF pediatric and adult patients. MCS by providing (a) ventricular mechanical unloading and (b) effective hemodynamic support to the periphery results in functional, structural, cellular and molecular changes, known as cardiac reverse remodeling. Herein, we analyze and synthesize the advances in our understanding of the biology of MCS-mediated reverse remodeling and myocardial recovery. The MCS investigational setting offers access to human tissue, providing an unparalleled opportunity in cardiovascular medicine to perform in-depth characterizations of myocardial biology and the associated molecular, cellular, and structural recovery signatures. These human tissue findings have triggered and effectively fueled a "bedside to bench and back" approach through a variety of knockout, inhibition or overexpression mechanistic investigations in vitro and in vivo using small animal models. These follow-up translational and basic science studies leveraging human tissue findings have unveiled mechanistic myocardial recovery pathways which are currently undergoing further testing for potential therapeutic drug development. Essentially, the field is advancing by extending the lessons learned from the MCS cardiac recovery investigational setting to develop therapies applicable to the greater, not end-stage, HF population. This review article focuses on the biological aspects of the MCS-mediated myocardial recovery and together with its companion review article, focused on the clinical aspects, they aim to provide a useful framework for clinicians and investigators.
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Affiliation(s)
- Eleni Tseliou
- Division of Cardiovascular Medicine, University of Utah Health, Salt Lake City, UT; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah Health, Salt Lake City, UT
| | - Kory J Lavine
- Division of Cardiology, Washington University School of Medicine, St Louis, MO
| | - Omar Wever-Pinzon
- Division of Cardiovascular Medicine, University of Utah Health, Salt Lake City, UT; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah Health, Salt Lake City, UT
| | - Veli K Topkara
- Department of Medicine, Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY
| | - Bart Meyns
- Department of Cardiology and Department of Cardiac Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Iki Adachi
- Division of Cardiac Surgery, Texas Children's Hospital, Houston, TX
| | - Daniel Zimpfer
- Department of Surgery, Division of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | | | - Daniel Burkhoff
- Department of Medicine, Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY; Cardiovascular Research Foundation (CRF), New York, NY
| | - Stavros G Drakos
- Division of Cardiovascular Medicine, University of Utah Health, Salt Lake City, UT; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah Health, Salt Lake City, UT.
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Jedrzejewska A, Braczko A, Kawecka A, Hellmann M, Siondalski P, Slominska E, Kutryb-Zajac B, Yacoub MH, Smolenski RT. Novel Targets for a Combination of Mechanical Unloading with Pharmacotherapy in Advanced Heart Failure. Int J Mol Sci 2022; 23:ijms23179886. [PMID: 36077285 PMCID: PMC9456495 DOI: 10.3390/ijms23179886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 08/22/2022] [Accepted: 08/25/2022] [Indexed: 12/19/2022] Open
Abstract
LVAD therapy is an effective rescue in acute and especially chronic cardiac failure. In several scenarios, it provides a platform for regeneration and sustained myocardial recovery. While unloading seems to be a key element, pharmacotherapy may provide powerful tools to enhance effective cardiac regeneration. The synergy between LVAD support and medical agents may ensure satisfying outcomes on cardiomyocyte recovery followed by improved quality and quantity of patient life. This review summarizes the previous and contemporary strategies for combining LVAD with pharmacotherapy and proposes new therapeutic targets. Regulation of metabolic pathways, enhancing mitochondrial biogenesis and function, immunomodulating treatment, and stem-cell therapies represent therapeutic areas that require further experimental and clinical studies on their effectiveness in combination with mechanical unloading.
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Affiliation(s)
- Agata Jedrzejewska
- Department of Biochemistry, Medical University of Gdansk, Debinki 1 Street, 80-211 Gdansk, Poland
| | - Alicja Braczko
- Department of Biochemistry, Medical University of Gdansk, Debinki 1 Street, 80-211 Gdansk, Poland
| | - Ada Kawecka
- Department of Biochemistry, Medical University of Gdansk, Debinki 1 Street, 80-211 Gdansk, Poland
| | - Marcin Hellmann
- Department of Cardiac Diagnostics, Medical University of Gdansk, Smoluchowskiego 17, 80-214 Gdansk, Poland
| | - Piotr Siondalski
- Department of Cardiac Surgery, Medical University of Gdansk, Debinki 7 Street, 80-211 Gdansk, Poland
| | - Ewa Slominska
- Department of Biochemistry, Medical University of Gdansk, Debinki 1 Street, 80-211 Gdansk, Poland
| | - Barbara Kutryb-Zajac
- Department of Biochemistry, Medical University of Gdansk, Debinki 1 Street, 80-211 Gdansk, Poland
- Correspondence: (B.K.-Z.); (R.T.S.)
| | - Magdi H. Yacoub
- Heart Science Centre, Imperial College of London at Harefield Hospital, Harefield UB9 6JH, UK
| | - Ryszard T. Smolenski
- Department of Biochemistry, Medical University of Gdansk, Debinki 1 Street, 80-211 Gdansk, Poland
- Correspondence: (B.K.-Z.); (R.T.S.)
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6
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Zhang RS, Hanff TC, Peters CJ, Evans PT, Marble J, Rame JE, Atluri P, Urgo K, Tanna MS, Mazurek JA, Acker MA, Cevasco M, Birati EY, Wald JW. Left Ventricular Assist Device as a Bridge to Recovery: Single Center Experience of Successful Device Explantation. ASAIO J 2022; 68:822-828. [PMID: 34560718 DOI: 10.1097/mat.0000000000001574] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Continuous-flow left ventricular assist devices (CF-LVAD) have been shown to enhance reverse remodeling and myocardial recovery in certain patients allowing for device removal. We sought to analyze the characteristics and describe outcomes of patients who underwent CF-LVAD explantation at a large academic center. We retrospectively identified all patients who underwent CF-LVAD explants due to recovery from 2006 to 2019. Patient baseline characteristics and data on pre- and postexplant evaluation were collected and analyzed. Of 421 patients who underwent CF-LVAD implantation, 13 underwent explantation (3.1%). Twelve HeartMate II and one HeartWare LVAD were explanted. All patients had nonischemic cardiomyopathy. Median time from heart failure diagnosis to LVAD implant was 12 months (interquartile range [IQR], 2-44) and the median time supported on LVAD was 22 months (IQR, 11-28). Two patients died within 30 days of explant. Three additional patients died during the follow-up period and all were noted to be nonadherent to medical therapy. After a mean follow-up duration of 5 years, overall survival was 52%. Mean pre-explant ejection fraction was 49%, which decreased at most recent follow-up to 32%. Mean pre-explant left ventricular internal diameter in diastole (LVIDD) was 4.37 cm and increased to 5.52 cm at most recent follow-up. Continuous-flow left ventricular assist device explantation is feasible and safe in select patients.
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Affiliation(s)
- Robert S Zhang
- From the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Thomas C Hanff
- From the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Carli J Peters
- From the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Peter T Evans
- From the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Judy Marble
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - J Eduardo Rame
- Division of Cardiovascular Medicine, Jefferson Hospital University, Philadelphia, Pennsylvania
| | - Pavan Atluri
- Division of Cardiothoracic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kimberly Urgo
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Monique S Tanna
- From the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jeremy A Mazurek
- From the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michael A Acker
- Division of Cardiothoracic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Marisa Cevasco
- Division of Cardiothoracic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Edo Y Birati
- From the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Joyce W Wald
- From the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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7
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Ibrahim M, Acker MA, Szeto W, Gutsche J, Williams M, Atluri P, Woods M, Richards T, Gardner TJ, McGarvey J, Epler M, Wald J, Rame E, Birati E, Bermudez C. Proposal for a trial of early left ventricular venting during venoarterial extracorporeal membrane oxygenation for cardiogenic shock. JTCVS OPEN 2021; 8:393-400. [PMID: 36004109 PMCID: PMC9390694 DOI: 10.1016/j.xjon.2021.07.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 07/26/2021] [Indexed: 11/07/2022]
Abstract
Objective Patients with profound cardiogenic shock may require venoarterial (VA) extracorporeal membrane oxygenation (ECMO) for circulatory support most commonly via the femoral vessels. The rate of cardiac recovery in this population remains low, possibly because peripheral VA-ECMO increases ventricular afterload. Whether direct ventricular unloading in peripheral VA-ECMO enhances cardiac recovery is unknown, but is being more frequently utilized. A randomized trial is warranted to evaluate the clinical effectiveness of percutaneous left ventricle venting to enhance cardiac recovery in the setting of VA-ECMO. Methods We describe the rationale, design, and initial testing of a randomized controlled trial of VA-ECMO with and without percutaneous left ventricle venting using a percutaneous micro-axial ventricular assist device. Results This is an ongoing prospective randomized controlled trial in adult patients with primary cardiac failure presenting in cardiogenic shock requiring peripheral VA-ECMO, designed to test the safety and effectiveness of percutaneous left ventricle venting in improving the rate of cardiac recovery. Conclusions The results of this nonindustry-sponsored trial will provide critical information on whether left ventricle unloading in peripheral VA-ECMO is safe and effective.
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8
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Effects of carvedilol and metoprolol on the myocardium during mechanical unloading in a rat heterotopic heart transplantation model. Cardiol Young 2021; 31:1269-1274. [PMID: 33745465 DOI: 10.1017/s1047951121000196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVES Left ventricular assist devices enable recovery from severe heart failure and serve as a bridge to heart transplantation. However, chronic mechanical unloading can impair myocardial recovery. We aimed to assess myocyte size, fibrosis, apoptosis, and β-adrenoreceptor levels after rats with left ventricle unloading induced by heterotopic heart transplantation were administered carvedilol and metoprolol. METHODS Thirty rats with heart transplants were divided randomly into control, carvedilol treatment, and metoprolol treatment groups. Follow-up was conducted after 2 and 4 weeks of unloading. RESULTS Carvedilol and metoprolol treatments did not prevent the decrease in myocyte diameter in unloaded left ventricles. Metoprolol significantly decreased the ratio of the fibrotic area in the unloaded heart, measured using Masson's trichrome staining after 2 weeks. However, carvedilol and metoprolol did not reduce apoptosis, based on measurements of terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labelling positive cells and the expression of caspase-3 in unloaded hearts after 2 and 4 weeks. Metoprolol treatment did not significantly decrease the mRNA expression of myocardial SERCA2a in the unloaded heart after 2 weeks. CONCLUSIONS Compared to carvedilol treatment, metoprolol treatment improved myocardial fibrosis and SERCA2a expression to a greater extent; however, neither drug prevented myocardial apoptosis.
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Shen S, Sewanan LR, Campbell SG. Evidence for synergy between sarcomeres and fibroblasts in an in vitro model of myocardial reverse remodeling. J Mol Cell Cardiol 2021; 158:11-25. [PMID: 33992697 DOI: 10.1016/j.yjmcc.2021.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 12/22/2022]
Abstract
We have created a novel in-vitro platform to study reverse remodeling of engineered heart tissue (EHT) after mechanical unloading. EHTs were created by seeding decellularized porcine myocardial sections with a mixture of primary neonatal rat ventricular myocytes and cardiac fibroblasts. Each end of the ribbon-like constructs was fixed to a plastic clip, allowing the tissues to be statically stretched or slackened. Inelastic deformation was introduced by stretching tissues by 20% of their original length. EHTs were subsequently unloaded by returning tissues to their original, shorter length. Mechanical characterization of EHTs immediately after unloading and at subsequent time points confirmed the presence of a reverse-remodeling process, through which stress-free tissue length was increased after chronic stretch but gradually decreased back to its original value within 9 days. When a cardiac myosin inhibitor was applied to tissues after unloading, EHTs failed to completely recover their passive and active mechanical properties, suggesting a role for actomyosin contraction in reverse remodeling. Selectively inhibiting cardiomyocyte contraction or fibroblast activity after mechanical unloading showed that contractile activity of both cell types was required to achieve full remodeling. Similar tests with EHTs formed from human induced pluripotent stem cell-derived cardiomyocytes also showed reverse remodeling that was enhanced when treated with omecamtiv mecarbil, a myosin activator. These experiments suggest essential roles for active sarcomeric contraction and fibroblast activity in reverse remodeling of myocardium after mechanical unloading. Our findings provide a mechanistic rationale for designing potential therapies to encourage reverse remodeling in patient hearts.
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Affiliation(s)
- Shi Shen
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Lorenzo R Sewanan
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Stuart G Campbell
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT, USA.
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10
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Abstract
This review provides a comprehensive overview of the past 25+ years of research into the development of left ventricular assist device (LVAD) to improve clinical outcomes in patients with severe end-stage heart failure and basic insights gained into the biology of heart failure gleaned from studies of hearts and myocardium of patients undergoing LVAD support. Clinical aspects of contemporary LVAD therapy, including evolving device technology, overall mortality, and complications, are reviewed. We explain the hemodynamic effects of LVAD support and how these lead to ventricular unloading. This includes a detailed review of the structural, cellular, and molecular aspects of LVAD-associated reverse remodeling. Synergisms between LVAD support and medical therapies for heart failure related to reverse remodeling, remission, and recovery are discussed within the context of both clinical outcomes and fundamental effects on myocardial biology. The incidence, clinical implications and factors most likely to be associated with improved ventricular function and remission of the heart failure are reviewed. Finally, we discuss recognized impediments to achieving myocardial recovery in the vast majority of LVAD-supported hearts and their implications for future research aimed at improving the overall rates of recovery.
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Affiliation(s)
| | | | - Gabriel Sayer
- Cardiovascular Research Foundation, New York, NY (D.B.)
| | - Nir Uriel
- Cardiovascular Research Foundation, New York, NY (D.B.)
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11
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Abstract
Heart failure is a widespread condition in the United States that is predicted to significantly increase in prevalence in the next decade. Many heart failure patients are given a left ventricular assist device (LVAD) while they wait for a heart transplant, while those that are not able to undergo a heart transplant may be given an LVAD permanently. However, past studies have observed a small subset of heart failure patients that recovered cardiac function of their native heart after being placed on an LVAD. As a result, some patients have been able to have their LVAD explanted and no longer needed a heart transplant. In this review, we analyzed the data of 15 studies that observed recovery of cardiac function in LVAD patients in order to investigate the effects that duration of LVAD support has on patient outcomes. From our review, we identified that there may be negative consequences of prolonged duration of mechanical support such as myocardial atrophy and abnormal calcium cycling as well as circumstances that may allow for a longer duration of LVAD support such as in patients using a continuous-flow LVAD, non-ischemic cardiomyopathy patients, and the specific pharmacological therapy.
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Affiliation(s)
- Binh N Pham
- University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Sandra V Chaparro
- University of Miami, Miller School of Medicine, Miami, FL, USA.
- Department of Medicine, Cardiovascular Division, University of Miami Miller School of Medicine, Clinical Research Building, 1120 NW 14th Street, Room 1110, Miami, FL, 33136, USA.
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12
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Järve A, Qadri F, Todiras M, Schmolke S, Alenina N, Bader M. Angiotensin-(1-7) Receptor Mas Deficiency Does Not Exacerbate Cardiac Atrophy Following High-Level Spinal Cord Injury in Mice. Front Physiol 2020; 11:203. [PMID: 32226394 PMCID: PMC7080696 DOI: 10.3389/fphys.2020.00203] [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: 11/15/2019] [Accepted: 02/21/2020] [Indexed: 11/13/2022] Open
Abstract
Experimental spinal cord injury (SCI) causes a morphological and functional deterioration of the heart, in which the renin–angiotensin system (RAS) might play a role. The recently discovered non-canonical axis of RAS with angiotensin-(1–7) and its receptor Mas, which is associated with cardioprotection could be essential to prevent damage to the heart following SCI. We investigated the cardiac consequences of SCI and the role of Mas in female wild-type (WT, n = 22) and mice deficient of Mas (Mas–/–, n = 25) which underwent spinal cord transection at thoracic level T4 (T4-Tx) or sham-operation by echocardiography (0, 7, 21, and 28 days post-SCI), histology and gene expression analysis at 1 or 2 months post-SCI. We found left ventricular mass reduction with preserved ejection fraction (EF) and fractional shortening in WT as well as Mas–/– mice. Cardiac output was reduced in Mas–/– mice, whereas stroke volume (SV) was reduced in WT T4-Tx mice. Echocardiographic indices did not differ between the genotypes. Smaller heart weight (HW) and smaller cardiomyocyte diameter at 1 month post-SCI compared to sham mice was independent of genotype. The muscle-specific E3 ubiquitin ligases Atrogin-1/MAFbx and MuRF1 were upregulated or showed a trend for upregulation in WT mice at 2 months post-SCI, respectively. Angiotensinogen gene expression was upregulated at 1 month post-SCI and angiotensin II receptor type 2 downregulated at 2 month post-SCI in Mas–/– mice. Mas was downregulated post-SCI. Cardiac atrophy following SCI, not exacerbated by lack of Mas, is a physiological reaction as there were no signs of cardiac pathology and dysfunction.
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Affiliation(s)
- Anne Järve
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research, Berlin, Germany
| | - Fatimunnisa Qadri
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany
| | - Mihail Todiras
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany.,Nicolae Testemiţanu State University of Medicine and Pharmacy, Chişinãu, Moldova
| | - Shirley Schmolke
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany
| | - Natalia Alenina
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research, Berlin, Germany
| | - Michael Bader
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research, Berlin, Germany.,Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute for Biology, University of Lübeck, Lübeck, Germany
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13
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Jordan JH, Castellino SM, Meléndez GC, Klepin HD, Ellis LR, Lamar Z, Vasu S, Kitzman DW, Ntim WO, Brubaker PH, Reichek N, D'Agostino RB, Hundley WG. Left Ventricular Mass Change After Anthracycline Chemotherapy. Circ Heart Fail 2019; 11:e004560. [PMID: 29991488 DOI: 10.1161/circheartfailure.117.004560] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 05/04/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND Myocardial atrophy and left ventricular (LV) mass reductions are associated with fatigue and exercise intolerance. The relationships between the receipt of anthracycline-based chemotherapy (Anth-bC) and changes in LV mass and heart failure (HF) symptomatology are unknown, as is their relationship to LV ejection fraction (LVEF), a widely used measurement performed in surveillance strategies designed to avert symptomatic HF associated with cancer treatment. METHODS AND RESULTS We performed blinded, serial assessments of body weight, LVEF and mass, LV-arterial coupling, aortic stiffness, and Minnesota Living with Heart Failure Questionnaire measures before and 6 months after initiating Anth-bC (n=61) and non-Anth-bC (n=15), and in 24 cancer-free controls using paired t and χ2 tests and multivariable linear models. Participants averaged 51±12 years, and 70% were women. Cancer diagnoses included breast cancer (53%), hematologic malignancy (42%), and soft tissue sarcoma (5%). We observed a 5% decline in both LVEF (P<0.0001) and LV mass (P=0.03) in the setting of increased aortic stiffness and disrupted ventricular-arterial coupling in those receiving Anth-bC but not other groups (P=0.11-0.92). A worsening of the Minnesota Living with Heart Failure Questionnaire score in Anth-bC recipients was associated with myocardial mass declines (r=-0.27; P<0.01) but not with LVEF declines (r=0.11; P=0.45). Moreover, this finding was independent of LVEF changes and body weight. CONCLUSIONS Early after Anth-bC, LV mass reductions associate with worsening HF symptomatology independent of LVEF. These data suggest an alternative mechanism whereby anthracyclines may contribute to HF symptomatology and raise the possibility that surveillance strategies during Anth-bC should also assess LV mass.
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Affiliation(s)
- Jennifer H Jordan
- Sections on Cardiovascular Medicine (J.H.J., G.C.M., S.V., D.W.K., W.O.N., W.G.H.)
| | | | - Giselle C Meléndez
- Sections on Cardiovascular Medicine (J.H.J., G.C.M., S.V., D.W.K., W.O.N., W.G.H.).,Department of Internal Medicine, Section on Comparative Medicine, Department of Pathology (G.C.M.)
| | | | | | | | - Sujethra Vasu
- Sections on Cardiovascular Medicine (J.H.J., G.C.M., S.V., D.W.K., W.O.N., W.G.H.)
| | - Dalane W Kitzman
- Sections on Cardiovascular Medicine (J.H.J., G.C.M., S.V., D.W.K., W.O.N., W.G.H.)
| | - William O Ntim
- Sections on Cardiovascular Medicine (J.H.J., G.C.M., S.V., D.W.K., W.O.N., W.G.H.)
| | - Peter H Brubaker
- Wake Forest School of Medicine, and Department of Health and Exercise Sciences (P.H.B)
| | - Nathaniel Reichek
- Wake Forest University, Winston-Salem, NC. Research and Education, The Heart Center, St Francis Hospital, Roslyn, NY (N.R.)
| | - Ralph B D'Agostino
- Department of Biostatistical Sciences, Division of Public Health Sciences (R.B.D'A.)
| | - W Gregory Hundley
- Sections on Cardiovascular Medicine (J.H.J., G.C.M., S.V., D.W.K., W.O.N., W.G.H.) .,Department of Radiological Sciences (W.G.H.)
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Westhofen S, Jelinek M, Dreher L, Biermann D, Martin J, Vitzhum H, Reichenspurner H, Ehmke H, Schwoerer AP. The heterotopic heart transplantation in mice as a small animal model to study mechanical unloading - Establishment of the procedure, perioperative management and postoperative scoring. PLoS One 2019; 14:e0214513. [PMID: 30978185 PMCID: PMC6461225 DOI: 10.1371/journal.pone.0214513] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 03/14/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Unloading of failing hearts by left ventricular assist devices induces an extensive cardiac remodeling which may lead to a reversal of the initial phenotype-or to its deterioration. The mechanisms underlying these processes are unclear. HYPOTHESIS Heterotopic heart transplantion (hHTX) is an accepted model for the study of mechanical unloading in rodents. The wide variety of genetically modified strains in mice provides an unique opportunity to examine remodeling pathways. However, the procedure is technically demanding and has not been extensively used in this area. To support investigators adopting this method, we present our experience establishing the abdominal hHTX in mice and describe refinements to the technique. METHODS In this model, the transplanted heart is vascularised but implanted in series, and therefore does not contribute to systemic circulation and results in a complete mechanical unloading of the donor heart. Training followed a systematic program using a combination of literature, video tutorials, cadaveric training, direct observation and training in live animals. RESULTS Successful transplantation was defined as a recipient surviving > 24 hours with a palpable, beating apex in the transplanted heart and was achieved after 20 transplants in live animals. A success rate of 90% was reached after 60 transplants. Operative time was shown to decrease in correlation with increasing number of procedures from 200 minutes to 45 minutes after 60 operations. Cold/warm ischemia time improved from 45/100 to 10/20 minutes. Key factors for success and trouble shootings were identified. CONCLUSION Abdominal hHTX in the mouse may enable future examination of specific pathways in unloading induced myocardial remodeling. Establishment of the technique, however, is challenging. Structured training programs utilising a variety of training methods can help to expedite the process. Postoperative management, including daily scoring increases animal wellbeing and helps to predict survival.
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Affiliation(s)
- Sumi Westhofen
- Department of Cardiovascular Surgery, University Heart Center, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
- * E-mail:
| | - Marisa Jelinek
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
- Department of Cellular and Integrative Physiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Leonie Dreher
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
- Department of Cellular and Integrative Physiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Daniel Biermann
- Department of Cardiovascular Surgery, University Heart Center, Hamburg, Germany
| | - Jack Martin
- Department of Surgery, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Helga Vitzhum
- Department of Cellular and Integrative Physiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Hermann Reichenspurner
- Department of Cardiovascular Surgery, University Heart Center, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Heimo Ehmke
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
- Department of Cellular and Integrative Physiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Alexander Peter Schwoerer
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
- Department of Cellular and Integrative Physiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
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15
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Gu K, Zhang Z, Chang Y, Gao B, Wan F. Computational analysis of the hemodynamic characteristics under interaction influence of β-blocker and LVAD. Biomed Eng Online 2018; 17:178. [PMID: 30509276 PMCID: PMC6276231 DOI: 10.1186/s12938-018-0602-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 11/09/2018] [Indexed: 12/12/2022] Open
Abstract
Background Hemodynamic characteristics of the interaction influence among support level and model of LVAD, and coupling β-blocker has not been reported. Methods In this study, the effect of support level and model of LVAD on cardiovascular hemodynamic characteristics is investigated. In addition, the effect of β-blocker on unloading with LVAD is analyzed to elucidate the mechanism of LVAD coupling β-blocker. A multi-scale model from cell level to system level is proposed. Moreover, LVAD coupling β-blocker has been researching to explain the hemodynamics of cardiovascular system. Results Myocardial force was decreased along with the increase of support level of LVAD, and co-pulse mode was the lowest among the three support modes. Additionally, the β-blocker combined with LVAD significantly reduced the left ventricular volume compared with LVAD support without β-blocker. However, the left ventricular pressure under both cases has no significant difference. External work of right ventricular was increased along with the growth of support level of only LVAD. The LVAD under co-pulse mode achieved the lowest right-ventricular EW among the three support modes. Conclusions Co-pulse mode with β-blocker could be an optimal strategy for promoting cardiac structure and function recovery.
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Affiliation(s)
- Kaiyun Gu
- Peking University Third Hospital, Peking University Health Science Center, 49 North Garden Rd, Haidian District, Beijing, 100191, China
| | - Zhe Zhang
- Peking University Third Hospital, Peking University Health Science Center, 49 North Garden Rd, Haidian District, Beijing, 100191, China.
| | - Yu Chang
- College of Life Science & Bio-Engineering, Beijing University of Technology, Beijing, 100124, China.
| | - Bin Gao
- College of Life Science & Bio-Engineering, Beijing University of Technology, Beijing, 100124, China
| | - Feng Wan
- Peking University Third Hospital, Peking University Health Science Center, 49 North Garden Rd, Haidian District, Beijing, 100191, China
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16
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Han HC. Understanding the mechanisms of mechanical unloading to achieve myocardial recovery. Am J Physiol Heart Circ Physiol 2018; 315:H1519-H1520. [DOI: 10.1152/ajpheart.00586.2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hai-Chao Han
- Department of Mechanical Engineering, University of Texas at San Antonio, and Biomedical Engineering Program, University of Texas at San Antonio-University of Texas Health Science Center at San Antonio, San Antonio, Texas
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17
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Castillero E, Ali ZA, Akashi H, Giangreco N, Wang C, Stöhr EJ, Ji R, Zhang X, Kheysin N, Park JES, Hegde S, Patel S, Stein S, Cuenca C, Leung D, Homma S, Tatonetti NP, Topkara VK, Takeda K, Colombo PC, Naka Y, Sweeney HL, Schulze PC, George I. Structural and functional cardiac profile after prolonged duration of mechanical unloading: potential implications for myocardial recovery. Am J Physiol Heart Circ Physiol 2018; 315:H1463-H1476. [PMID: 30141986 PMCID: PMC6297806 DOI: 10.1152/ajpheart.00187.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/18/2018] [Accepted: 08/02/2018] [Indexed: 11/22/2022]
Abstract
Clinical and experimental studies have suggested that the duration of left ventricular assist device (LVAD) support may affect remodeling of the failing heart. We aimed to 1) characterize the changes in Ca2+/calmodulin-dependent protein kinase type-IIδ (CaMKIIδ), growth signaling, structural proteins, fibrosis, apoptosis, and gene expression before and after LVAD support and 2) assess whether the duration of support correlated with improvement or worsening of reverse remodeling. Left ventricular apex tissue and serum pairs were collected in patients with dilated cardiomyopathy ( n = 25, 23 men and 2 women) at LVAD implantation and after LVAD support at cardiac transplantation/LVAD explantation. Normal cardiac tissue was obtained from healthy hearts ( n = 4) and normal serum from age-matched control hearts ( n = 4). The duration of LVAD support ranged from 48 to 1,170 days (median duration: 270 days). LVAD support was associated with CaMKIIδ activation, increased nuclear myocyte enhancer factor 2, sustained histone deacetylase-4 phosphorylation, increased circulating and cardiac myostatin (MSTN) and MSTN signaling mediated by SMAD2, ongoing structural protein dysregulation and sustained fibrosis and apoptosis (all P < 0.05). Increased CaMKIIδ phosphorylation, nuclear myocyte enhancer factor 2, and cardiac MSTN significantly correlated with the duration of support. Phosphorylation of SMAD2 and apoptosis decreased with a shorter duration of LVAD support but increased with a longer duration of LVAD support. Further study is needed to define the optimal duration of LVAD support in patients with dilated cardiomyopathy. NEW & NOTEWORTHY A long duration of left ventricular assist device support may be detrimental for myocardial recovery, based on myocardial tissue experiments in patients with prolonged support showing significantly worsened activation of Ca2+/calmodulin-dependent protein kinase-IIδ, increased nuclear myocyte enhancer factor 2, increased myostatin and its signaling by SMAD2, and apoptosis as well as sustained histone deacetylase-4 phosphorylation, structural protein dysregulation, and fibrosis.
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Affiliation(s)
- Estibaliz Castillero
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Ziad A Ali
- Division of Cardiology, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Hirokazu Akashi
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Nicholas Giangreco
- Department of Biomedical Informatics, Systems Biology, Institute for Genomic Medicine, Data Science Institute, Columbia University , New York, New York
| | - Catherine Wang
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Eric J Stöhr
- Division of Cardiology, College of Physicians and Surgeons of Columbia University , New York, New York
- School of Sport and Health Sciences, Cardiff Metropolitan University , Cardiff , United Kingdom
| | - Ruping Ji
- Division of Cardiology, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Xiaokan Zhang
- Division of Cardiology, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Nathaniel Kheysin
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Joo-Eun S Park
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Sheetal Hegde
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Sanatkumar Patel
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Samantha Stein
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Carlos Cuenca
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Diana Leung
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Shunichi Homma
- Division of Cardiology, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Nicholas P Tatonetti
- Department of Biomedical Informatics, Systems Biology, Institute for Genomic Medicine, Data Science Institute, Columbia University , New York, New York
| | - Veli K Topkara
- Division of Cardiology, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Koji Takeda
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Paolo C Colombo
- Division of Cardiology, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Yoshifumi Naka
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
| | - H Lee Sweeney
- Department of Pharmacology, University of Florida , Gainesville, Florida
| | - P Christian Schulze
- Division of Cardiology, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Isaac George
- Division of Cardiothoracic Surgery, College of Physicians and Surgeons of Columbia University , New York, New York
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18
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Isovolumic loading of the failing heart by intraventricular placement of a spring expander attenuates cardiac atrophy after heterotopic heart transplantation. Biosci Rep 2018; 38:BSR20180371. [PMID: 29743195 PMCID: PMC6019382 DOI: 10.1042/bsr20180371] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 04/20/2018] [Accepted: 04/30/2018] [Indexed: 12/21/2022] Open
Abstract
Cardiac atrophy is the most common complication of prolonged application of the left ventricle (LV) assist device (LVAD) in patients with advanced heart failure (HF). Our aim was to evaluate the course of unloading-induced cardiac atrophy in rats with failing hearts, and to examine if increased isovolumic loading obtained by intraventricular implantation of an especially designed spring expander would attenuate this process. Heterotopic abdominal heart transplantation (HTx) was used as a rat model of heart unloading. HF was induced by volume overload achieved by creation of the aorto-caval fistula (ACF). The degree of cardiac atrophy was assessed as the weight ratio of the heterotopically transplanted heart (HW) to the control heart. Isovolumic loading was increased by intraventricular implantation of a stainless steel three-branch spring expander. The course of cardiac atrophy was evaluated on days 7, 14, 21, and 28 after HTx Seven days unloading by HTx in failing hearts sufficed to substantially decrease the HW (-59 ± 3%), the decrease progressed when measured on days 14, 21, and 28 after HTx Implantation of the spring expander significantly reduced the decreases in whole HW at all the time points (-39 ± 3 compared with -59 ± 3, -52 ± 2 compared with -69 ± 3, -51 ± 2 compared with -71 ± 2, and -44 ± 2 compared with -71 ± 3%, respectively; P<0.05 in each case). We conclude that the enhanced isovolumic heart loading obtained by implantation of the spring expander attenuates the development of unloading-induced cardiac atrophy in the failing rat heart.
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19
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Kwiatkowski P, Sai-Sudhakar C, Philips A, Parthasarathy S, Sun B. Development of a Novel Large Animal Model of Ischemic Heart Failure Using Autologous Platelet Aggregates. Int J Artif Organs 2018. [DOI: 10.1177/039139881003300201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Current animal models of heart failure lack the biomass of thrombus that occurs in patients undergoing myocardial infarction. We propose a novel animal model of ischemic cardiomyopathy developed by sequential direct injections of autologous platelet aggregates into the coronary circulation resulting in development of ischemic cardiac insufficiency. Methods Autologous platelets from adult sheep were isolated and aggregated. Aggregated platelets were then injected into the coronary circulation of anesthetized animals under fluoroscopic guidance. Troponin I levels were monitored for first three days after embolization to validate cardiac tissue injury. Progression of heart failure was corroborated by monitoring changes in echo-based assessment of ejection fraction and left ventricular end-systolic and end-diastolic dimensions. Thrombus-based obstruction of coronary artery was confirmed with histopathology review by mepacrine labeling of pre-aggregated platelets. Results All experimental animals developed heart failure-like cardiac insufficiency confirmed by elevated levels of troponin I and associated with significant drop in the ejection fraction. Conclusions Sequential injections of aggregated platelets into coronary circulation lead to progressive development of ischemic cardiac insufficiency. This phenomenon seems to mimic development of ischemic heart failure seen in human patients and opens multiple research opportunities to fill the existing gap between basic research and clinical practice.
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Affiliation(s)
- Pawel Kwiatkowski
- Division of Cardiothoracic Surgery, Department of Surgery, The Ohio State University Medical Center, Columbus, OH - USA
| | - Chittoor Sai-Sudhakar
- Division of Cardiothoracic Surgery, Department of Surgery, The Ohio State University Medical Center, Columbus, OH - USA
| | - Angela Philips
- Division of Cardiothoracic Surgery, Department of Surgery, The Ohio State University Medical Center, Columbus, OH - USA
| | - Sampath Parthasarathy
- Division of Cardiothoracic Surgery, Department of Surgery, The Ohio State University Medical Center, Columbus, OH - USA
| | - Benjamin Sun
- Division of Cardiothoracic Surgery, Department of Surgery, The Ohio State University Medical Center, Columbus, OH - USA
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20
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Files MD, Portman MA, McMullan DM, Bhat AH. Left ventricular mass response to extra-corporeal life support (ECLS) in infants. PROGRESS IN PEDIATRIC CARDIOLOGY 2017. [DOI: 10.1016/j.ppedcard.2017.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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21
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Wever-Pinzon J, Selzman CH, Stoddard G, Wever-Pinzon O, Catino A, Kfoury AG, Diakos NA, Reid BB, McKellar S, Bonios M, Koliopoulou A, Budge D, Kelkhoff A, Stehlik J, Fang JC, Drakos SG. Impact of Ischemic Heart Failure Etiology on Cardiac Recovery During Mechanical Unloading. J Am Coll Cardiol 2017; 68:1741-1752. [PMID: 27737740 DOI: 10.1016/j.jacc.2016.07.756] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/07/2016] [Accepted: 07/12/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND Small-scale studies focused mainly on nonischemic cardiomyopathy (NICM) have shown that a subset of left ventricular assist device (LVAD) patients can achieve significant improvement of their native heart function, but the impact of ischemic cardiomyopathy (ICM) has not been specifically investigated. Many patients with acute myocardial infarction are discharged from their index hospitalization without heart failure (HF), only to return much later with overt HF syndrome, mainly caused by chronic remodeling of the noninfarcted region of the myocardium. OBJECTIVES This study sought to prospectively investigate the effect of ICM HF etiology on LVAD-associated improvement of cardiac structure and function using NICM as control. METHODS Consecutive patients (n = 154) with documented chronic and dilated cardiomyopathy (ICM, n = 61; NICM, n = 93) requiring durable support with continuous-flow LVAD were prospectively evaluated with serial echocardiograms and right heart catheterizations. RESULTS In patients supported with LVAD for at least 6 months, we found that 5% of subjects with ICM and 21% of subjects with NICM achieved left ventricular ejection fraction ≥40% (p = 0.034). LV end-diastolic and end-systolic volumes and diastolic function were significantly and similarly improved in patients with ICM and NICM. CONCLUSIONS LVAD-associated unloading for 6 months resulted in a substantial improvement in myocardial structure, and systolic and diastolic function in 1 in 20 ICM and 1 in 5 NICM patients. These specific incidence and timeline findings may provide guidance in clinical practice and research design for sequencing and prioritizing advanced HF and heart transplantation therapeutic options in patients with ICM and NICM.
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Affiliation(s)
- James Wever-Pinzon
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Craig H Selzman
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah; University of Utah Molecular Medicine Program, Salt Lake City, Utah
| | - Greg Stoddard
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Omar Wever-Pinzon
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Anna Catino
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Abdallah G Kfoury
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Nikolaos A Diakos
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah; University of Utah Molecular Medicine Program, Salt Lake City, Utah
| | - Bruce B Reid
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Stephen McKellar
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah; University of Utah Molecular Medicine Program, Salt Lake City, Utah
| | - Michael Bonios
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Antigone Koliopoulou
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Deborah Budge
- University of Utah Molecular Medicine Program, Salt Lake City, Utah
| | - Aaron Kelkhoff
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Josef Stehlik
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - James C Fang
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Stavros G Drakos
- Utah Transplantation Affiliated Hospitals Cardiac Transplant Program, University of Utah Health Sciences Center, Intermountain Medical Center, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah; University of Utah Molecular Medicine Program, Salt Lake City, Utah.
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22
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Heterotopic Abdominal Rat Heart Transplantation as a Model to Investigate Volume Dependency of Myocardial Remodeling. Transplantation 2017; 101:498-505. [PMID: 27906830 DOI: 10.1097/tp.0000000000001585] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Heterotopic abdominal rat heart transplantation has been extensively used to investigate ischemic-reperfusion injury, immunological consequences during heart transplantations and also to study remodeling of the myocardium due to volume unloading. We provide a unique review on the latter and present a summary of the experimental studies on rat heart transplantation to illustrate changes that occur to the myocardium due to volume unloading. We divided the literature based on whether normal or failing rat heart models were used. This analysis may provide a basis to understand the physiological effects of mechanical circulatory support therapy.
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Zhang Q, Gao B, Chang Y. Computational Analysis of Intra-Ventricular Flow Pattern Under Partial and Full Support of BJUT-II VAD. Med Sci Monit 2017; 23:1043-1054. [PMID: 28239142 PMCID: PMC5341908 DOI: 10.12659/msm.900481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background Partial support, as a novel support mode, has been widely applied in clinical practice and widely studied. However, the precise mechanism of partial support of LVAD in the intra-ventricular flow pattern is unclear. Material/Methods In this study, a patient-specific left ventricular geometric model was reconstructed based on CT data. The intra-ventricular flow pattern under 3 simulated conditions – “heart failure”, “partial support”, and “full support” – were simulated by using fluid-structure interaction (FSI). The blood flow pattern, wall shear stress (WSS), time-average wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) were calculated to evaluate the hemodynamic effects. Results The results demonstrate that the intra-ventricular flow pattern is significantly changed by the support level of BJUT-II VAD. The intra-ventricular vortex was enhanced under partial support and was eliminated under full support, and the high OSI and RRT regions changed from the septum wall to the cardiac apex. Conclusions In brief, the support level of the BJUT-II VAD has significant effects on the intra-ventricular flow pattern. The partial support mode of BJUT-II VAD can enhance the intra-ventricular vortex, while the distribution of high OSI and RRT moved from the septum wall to the cardiac apex. Hence, the partial support mode of BJUT-II VAD can provide more benefit for intra-ventricular flow pattern.
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Affiliation(s)
- Qi Zhang
- School of Life Sciences and BioEngineering, Beijing University of Technology, Beijing, China (mainland)
| | - Bin Gao
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, China (mainland)
| | - Yu Chang
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, China (mainland)
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Depressed Myocardial Contractility: Can It Be Rescued? Am J Med Sci 2016; 352:428-432. [PMID: 27776727 DOI: 10.1016/j.amjms.2016.05.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 05/24/2016] [Indexed: 11/20/2022]
Abstract
Current dogma suggests patients with advanced systolic heart failure have an irreversible depression in myocardial contractility. Recent experience with improved ventricular function during continuous flow ventricular assist devices used as destination therapy would suggest otherwise. Herein, cellular and molecular signaling involved in reversing depressed myocardial contractility would be addressed. This includes cardiomyocyte thyroid hormone signaling responsible for the reexpression of fetal gene program that preserves cell efficiency (work and energy consumed) and the rescue of an endogenous population of atrophic myocytes bordering on microdomains of fibrosis to improve contractile mass.
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Fu X, Segiser A, Carrel TP, Tevaearai Stahel HT, Most H. Rat Heterotopic Heart Transplantation Model to Investigate Unloading-Induced Myocardial Remodeling. Front Cardiovasc Med 2016; 3:34. [PMID: 27807535 PMCID: PMC5069686 DOI: 10.3389/fcvm.2016.00034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/20/2016] [Indexed: 12/17/2022] Open
Abstract
Unloading of the failing left ventricle in order to achieve myocardial reverse remodeling and improvement of contractile function has been developed as a strategy with the increasing frequency of implantation of left ventricular assist devices in clinical practice. But, reverse remodeling remains an elusive target, with high variability and exact mechanisms still largely unclear. The small animal model of heterotopic heart transplantation (hHTX) in rodents has been widely implemented to study the effects of complete and partial unloading on cardiac failing and non-failing tissue to better understand the structural and molecular changes that underlie myocardial recovery. We herein review the current knowledge on the effects of volume unloading the left ventricle via different methods of hHTX in rats, differentiating between changes that contribute to functional recovery and adverse effects observed in unloaded myocardium. We focus on methodological aspects of heterotopic transplantation, which increase the correlation between the animal model and the setting of the failing unloaded human heart. Last, but not least, we describe the late use of sophisticated techniques to acquire data, such as small animal MRI and catheterization, as well as ways to assess unloaded hearts under "reloaded" conditions. While giving regard to certain limitations, heterotopic rat heart transplantation certainly represents the crucial model to mimic unloading-induced changes in the heart and as such the intricacies and challenges deserve highest consideration. Careful translational research will further improve our knowledge of the reverse remodeling process and how to potentiate its effect in order to achieve recovery of contractile function in more patients.
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Affiliation(s)
- Xuebin Fu
- Department of Cardiac and Vascular Surgery, Inselspital University Hospital , Berne , Switzerland
| | - Adrian Segiser
- Department of Cardiac and Vascular Surgery, Inselspital University Hospital , Berne , Switzerland
| | - Thierry P Carrel
- Department of Cardiac and Vascular Surgery, Inselspital University Hospital , Berne , Switzerland
| | | | - Henriette Most
- Department of Cardiac and Vascular Surgery, Inselspital University Hospital , Berne , Switzerland
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Zhang Y, Gao B, Yu C. The hemodynamic effects of the LVAD outflow cannula location on the thrombi distribution in the aorta: A primary numerical study. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2016; 133:217-227. [PMID: 27393812 DOI: 10.1016/j.cmpb.2016.05.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 05/06/2016] [Accepted: 05/31/2016] [Indexed: 06/06/2023]
Abstract
Although a growing number of patients undergo LVAD implantation for heart failure treatment, thrombi are still the devastating complication for patients who used LVAD. LVAD outflow cannula location and thrombi generation sources were hypothesized to affect the thrombi distribution in the aorta. To test this hypothesis, numerical studies were conducted by using computational fluid dynamic (CFD) theory. Two anastomotic configurations, in which the LVAD outflow cannula is anastomosed to the anterior and lateral ascending aortic wall (named as anterior configurations and lateral configurations, respectively), are designed. The particles, whose sized are same as those of thrombi, are released at the LVAD output cannula and the aortic valve (named as thrombiP and thrombiL, respectively) to calculate the distribution of thrombi. The simulation results demonstrate that the thrombi distribution in the aorta is significantly affected by the LVAD outflow cannula location. In anterior configuration, the thrombi probability of entering into the three branches is 23.60%, while that in lateral configuration is 36.68%. Similarly, in anterior configuration, the thrombi probabilities of entering into brachiocephalic artery, left common carotid artery and left subclavian artery, is 8.51%, 9.64%, 5.45%, respectively, while that in lateral configuration it is 11.39%, 3.09%, 22.20% respectively. Moreover, the origins of thrombi could affect their distributions in the aorta. In anterior configuration, the thrombiP has a lower probability to enter into the three branches than thrombiL (12% vs. 25%). In contrast, in lateral configuration, the thrombiP has a higher probability to enter into the three branches than thrombiL (47% vs. 35%). In brief, the LVAD outflow cannula location significantly affects the distribution of thrombi in the aorta. Thus, in the clinical practice, the selection of outflow location of LVAD and the risk of thrombi formed in the left ventricle should be paid more attention than before.
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Affiliation(s)
- Yage Zhang
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing 100124, China
| | - Bin Gao
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing 100124, China
| | - Chang Yu
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing 100124, China.
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27
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Vuohelainen V, Hämäläinen M, Paavonen T, Karlsson S, Moilanen E, Mennander A. Inhibition of monoamine oxidase A increases recovery after experimental cardiac arrest. Interact Cardiovasc Thorac Surg 2015; 21:441-9. [PMID: 26116370 DOI: 10.1093/icvts/ivv175] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 05/27/2015] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Perioperative myocardial infarction (MI) with ischaemia-reperfusion injury (IRI) is a devastating entity occurring in 1-2% of patients after cardiac surgery. The molecular pathway leading to myocardial cellular destruction after MI may include monoamine oxidases. We experimentally investigated whether moclobemide, a monoamine oxidase inhibitor, enhances myocardial recovery after cardiac arrest and MI. METHODS Fifty-six syngeneic Fischer rats underwent heterotopic cardiac transplantation to induce reversible IRI after cardiac arrest. Twenty-eight rats also underwent permanent ligation of the left anterior descending coronary artery to induce MI after cardiac arrest. Twenty-eight rats with or without MI were treated with subcutaneous moclobemide 10 mg/kg/day. Methods used to study myocardial recovery were microdialysis for intramyocardial metabolism, histology and quantitative reverse-transcription polymerase chain reaction for high-mobility group box-1 (HMGB1), haeme oxygenase-1 (HO-1), interleukin-6, hypoxia-inducible factor 1α and macrophages (CD68). RESULTS Pyruvate increased in MI treated with moclobemide versus IRI with moclobemide (29.19 ± 7.64 vs 13.86 ± 8.49 µM, P = 0.028), reflecting metabolic activity after cardiac arrest and reperfusion. Myocardial inflammation increased in MI compared with IRI after 1 h (0.80 ± 0.56 vs 0, point score units [PSUs], P = 0.003), but decreased after 5 days in MI treated with moclobemide versus MI alone (0.80 ± 0.83 vs 2.00 ± 0.70, PSU, P = 0.033). Expressions of HMGB1, CD68 and HO-1 decreased in MI treated with moclobemide versus MI alone (1.33 ± 0.20 vs 1.75 ± 0.24, fold changes [FCs], P = 0.028; 5.15 ± 1.10 vs 9.59 ± 2.75, FC, P = 0.050; 10.41 ± 4.17 vs 21.28 ± 10.01, FC, P = 0.047), indicating myocardial recovery and increased cellularity of remote intramyocardial arteries. CONCLUSIONS Moclobemide enhances myocardial recovery after cardiac arrest and MI; inhibition of remote myocardial changes may be achieved by targeting treatment against monoamine oxidase.
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Affiliation(s)
- Vilma Vuohelainen
- Heart Hospital, Cardiac Research, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - Mari Hämäläinen
- The Immunopharmacology Research Group, University of Tampere School of Medicine, Tampere, Finland
| | - Timo Paavonen
- Department of Pathology, Fimlab, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - Sari Karlsson
- Department of Anesthesiology, Intensive Care Unit, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - Eeva Moilanen
- The Immunopharmacology Research Group, University of Tampere School of Medicine, Tampere, Finland
| | - Ari Mennander
- Heart Hospital, Cardiac Research, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
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Liu Y, Maureira P, Gauchotte G, Falanga A, Marie V, Olivier A, Groubatch F, Gu C, Marie PY, Tran N. Effect of chronic left ventricular unloading on myocardial remodeling: Multimodal assessment of two heterotopic heart transplantation techniques. J Heart Lung Transplant 2014; 34:594-603. [PMID: 25703962 DOI: 10.1016/j.healun.2014.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/05/2014] [Accepted: 11/12/2014] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Cardiac recovery is possible by means of mechanical unloading yet remains rare. Excessive unloading-associated myocardial atrophy and fibrosis may adversely affect the process of reverse remodeling. In this study, we sought to evaluate the effect of different intensities of chronic left ventricular (LV) unloading on myocardial remodeling. METHODS Twenty-five isogenic Lewis rats underwent complete LV unloading (CU, n = 15) induced by heterotopic heart transplantation or partial LV unloading (PU, n = 10) by heterotopic heart-lung transplantation. Information obtained from serial echocardiography, 2-deoxy-2[(18)F]fluoro-d-glucose ((18)F-FDG)-positron emission tomography, and an LV pressure-volume catheter were used to evaluate the morphology, glucose metabolism, and hemodynamic performance of the orthotopic hearts and heterotopic transplants over 4 weeks. Cell size, collagen content, tissue cytokines (interleukin [IL]-1α, IL-2, IL-6, IL-10, tumor necrosis factor-α, and vascular endothelial growth factor), and matrix metalloproteinase-2 and -9 were also determined. The recorded parameters included LV end-systolic dimension, LV end-diastolic dimension, posterior wall thickness, diastolic interventricular septum thickness, LV fractional shortening, and LV ejection fraction. RESULTS We demonstrated an LV load-dependent relationship using echo-based structural (left posterior wall thickness, diastolic interventricular septum thickness, and left ventricular end-diastolic dimension) and functional (LV fractional shortening and LV ejection fraction) parameters, as well as an (18)F-FDG uptake (all p < 0.05). This load-dependent relationship was also evidenced in measurements from the pressure-volume conductance catheter (stroke volume, stroke work, cardiac output, dP/dTmax, and -dP/dTmin; all p < 0.05). Significant myocardial atrophy and fibrosis were observed in unloaded hearts, whereas concentrations of cytokines and matrix metalloproteinases were comparable in both unloading conditions. CONCLUSIONS Partial and complete unloading affected the remodeling of non-failing hearts in a rodent model to different extents on myocardial atrophy, fibrosis, glucose metabolism, and mechanical work. Cardiac atrophy is the prominent change after mechanical unloading, which exaggerates the proportion of total collagen that is responsible for diastolic dysfunction.
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Affiliation(s)
- Yihua Liu
- Department of Cardiovascular Surgery And Heart Transplantation, Centre Hospitalier Universitaire-Nancy, Nancy, France; School of Surgery, Unité Institut National de la Santé et de la Recherche Médicale 1116, Université de Lorraine, Nancy, France; Department of Cardiothoracic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Pablo Maureira
- Department of Cardiovascular Surgery And Heart Transplantation, Centre Hospitalier Universitaire-Nancy, Nancy, France; School of Surgery, Unité Institut National de la Santé et de la Recherche Médicale 1116, Université de Lorraine, Nancy, France.
| | | | - Aude Falanga
- School of Surgery, Unité Institut National de la Santé et de la Recherche Médicale 1116, Université de Lorraine, Nancy, France
| | - Venessa Marie
- School of Surgery, Unité Institut National de la Santé et de la Recherche Médicale 1116, Université de Lorraine, Nancy, France
| | | | - Frederique Groubatch
- School of Surgery, Unité Institut National de la Santé et de la Recherche Médicale 1116, Université de Lorraine, Nancy, France
| | - Celine Gu
- Medical Imaging, Centre Hospitalier Universitaire-Nancy, Nancy, France
| | - Pierre-Yves Marie
- School of Surgery, Unité Institut National de la Santé et de la Recherche Médicale 1116, Université de Lorraine, Nancy, France; Medical Imaging, Centre Hospitalier Universitaire-Nancy, Nancy, France
| | - Nguyen Tran
- School of Surgery, Unité Institut National de la Santé et de la Recherche Médicale 1116, Université de Lorraine, Nancy, France
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29
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Navaratnarajah M, Siedlecka U, Ibrahim M, van Doorn C, Soppa G, Gandhi A, Shah A, Kukadia P, Yacoub MH, Terracciano CM. Impact of combined clenbuterol and metoprolol therapy on reverse remodelling during mechanical unloading. PLoS One 2014; 9:e92909. [PMID: 25268495 PMCID: PMC4181979 DOI: 10.1371/journal.pone.0092909] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 02/26/2014] [Indexed: 01/19/2023] Open
Abstract
Background Clenbuterol (Cl), a β2 agonist, is associated with enhanced myocardial recovery during left ventricular assist device (LVAD) support, and exerts beneficial remodelling effects during mechanical unloading (MU) in rodent heart failure (HF). However, the specific effects of combined Cl+β1 blockade during MU are unknown. Methods and Results We studied the chronic effects (4 weeks) of β2-adrenoceptor (AR) stimulation via Cl (2 mg/kg/day) alone, and in combination with β1-AR blockade using metoprolol ((Met), 250 mg/kg/day), on whole heart/cell structure, function and excitation-contraction (EC) coupling in failing (induced by left coronary artery (LCA) ligation), and unloaded (induced by heterotopic abdominal heart transplantation (HATx)) failing rat hearts. Combined Cl+Met therapy displayed favourable effects in HF: Met enhanced Cl's improvement in ejection fraction (EF) whilst preventing Cl-induced hypertrophy and tachycardia. During MU combined therapy was less beneficial than either mono-therapy. Met, not Cl, prevented MU-induced myocardial atrophy, with increased atrophy occurring during combined therapy. MU-induced recovery of Ca2+ transient amplitude, speed of Ca2+ release and sarcoplasmic reticulum Ca2+ content was enhanced equally by Cl or Met mono-therapy, but these benefits, together with Cl's enhancement of sarcomeric contraction speed, and MU-induced recovery of Ca2+ spark frequency, disappeared during combined therapy. Conclusions Combined Cl+Met therapy shows superior functional effects to mono-therapy in rodent HF, but appears inferior to either mono-therapy in enhancing MU-induced recovery of EC coupling. These results suggest that combined β2-AR simulation +β1-AR blockade therapy is likely to be a safe and beneficial therapeutic HF strategy, but is not as effective as mono-therapy in enhancing myocardial recovery during LVAD support.
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Affiliation(s)
- Manoraj Navaratnarajah
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
- * E-mail:
| | - Urszula Siedlecka
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Michael Ibrahim
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Carin van Doorn
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Gopal Soppa
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Ajay Gandhi
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Adarsh Shah
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Punam Kukadia
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Magdi H. Yacoub
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Cesare M. Terracciano
- Harefield Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, United Kingdom
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Abstract
The discovery of substantial myocardial improvement following the mechanical unloading afforded by left ventricular assist device (LVAD) therapy challenged the dogma of heart failure being irreversible. Since then, a significant experience with the use of LVAD therapy as a bridge to recovery has accumulated. The discovery of substantial structural and functional changes (reverse remodeling) in the myocardium has resulted in an intensive effort to define the biologic determinants of the reversibility of these changes. Herein the scientific foundations, clinical practice, and future of the use of LVADs as a bridge to recovery are reviewed.
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Affiliation(s)
- Michael Ibrahim
- Department of Cardiothoracic Surgery, Heart Science Centre, Harefield Hospital, National Heart and Lung Institute, Hill End Road, London UB9 6JH, UK
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31
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Rapamycin attenuated cardiac hypertrophy induced by isoproterenol and maintained energy homeostasis via inhibiting NF-κB activation. Mediators Inflamm 2014; 2014:868753. [PMID: 25045214 PMCID: PMC4089551 DOI: 10.1155/2014/868753] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/11/2014] [Accepted: 05/14/2014] [Indexed: 12/16/2022] Open
Abstract
Rapamycin, also known as sirolimus, is an immunosuppressant drug used to prevent rejection organ (especially kidney) transplantation. However, little is known about the role of Rapa in cardiac hypertrophy induced by isoproterenol and its underlying mechanism. In this study, Rapa was administrated intraperitoneally for one week after the rat model of cardiac hypertrophy induced by isoproterenol established. Rapa was demonstrated to attenuate isoproterenol-induced cardiac hypertrophy, maintain the structure integrity and functional performance of mitochondria, and upregulate genes related to fatty acid metabolism in hypertrophied hearts. To further study the implication of NF-κB in the protective role of Rapa, cardiomyocytes were pretreated with TNF-α or transfected with siRNA against NF-κB/p65 subunit. It was revealed that the upregulation of extracellular circulating proinflammatory cytokines induced by isoproterenol was able to be reversed by Rapa, which was dependent on NF-κB pathway. Furthermore, the regression of cardiac hypertrophy and maintaining energy homeostasis by Rapa in cardiomyocytes may be attributed to the inactivation of NF-κB. Our results shed new light on mechanisms underlying the protective role of Rapa against cardiac hypertrophy induced by isoproterenol, suggesting that blocking proinflammatory response by Rapa might contribute to the maintenance of energy homeostasis during the progression of cardiac hypertrophy.
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Pokorný M, Cervenka L, Netuka I, Pirk J, Koňařík M, Malý J. Ventricular assist devices in heart failure: how to support the heart but prevent atrophy? Physiol Res 2014; 63:147-56. [PMID: 24779607 DOI: 10.33549/physiolres.932617] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Ventricular assist devices (VAD) have recently established themselves as an irreplaceable therapeutic modality of terminal heart failure. Because of the worldwide shortage of donors, ventricular assist devices play a key role in modern heart failure therapy. Some clinical data have revealed the possibility of cardiac recovery during VAD application. On the other hand, both clinical and experimental studies indicate the risk of the cardiac atrophy development, especially after prolonged mechanical unloading. Little is known about the specific mechanisms governing the unloading-induced cardiac atrophy and about the exact ultrastructural changes in cardiomyocytes, and even less is known about the ways in which possible therapeutical interventions may affect heart atrophy. One aim of this review was to present important aspects of the development of VAD-related cardiac atrophy in humans and we also review the most significant observations linking clinical data and those derived from studies using experimental models. The focus of this article was to review current methods applied to alleviate cardiac atrophy which follows mechanical unloading of the heart. Out of many pharmacological agents studied, only the selective beta2 agonist clenbuterol has been proved to have a significantly beneficial effect on unloading-induced atrophy. Mechanical means of atrophy alleviation also seem to be effective and promising.
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Affiliation(s)
- M Pokorný
- Department of Cardiovascular Surgery, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
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Gu K, Gao B, Chang Y, Zeng Y. The Hemodynamic Effect of Phase Differences Between the BJUT-II Ventricular Assist Device and Native Heart on the Cardiovascular System. Artif Organs 2014; 38:914-23. [DOI: 10.1111/aor.12298] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kaiyun Gu
- College of Life Science and Bioengineering; Beijing University of Technology; Beijing China
| | - Bin Gao
- College of Life Science and Bioengineering; Beijing University of Technology; Beijing China
| | - Yu Chang
- College of Life Science and Bioengineering; Beijing University of Technology; Beijing China
| | - Yi Zeng
- College of Life Science and Bioengineering; Beijing University of Technology; Beijing China
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Ibrahim M, Kukadia P, Siedlecka U, Cartledge JE, Navaratnarajah M, Tokar S, Van Doorn C, Tsang VT, Gorelik J, Yacoub MH, Terracciano CM. Cardiomyocyte Ca2+ handling and structure is regulated by degree and duration of mechanical load variation. J Cell Mol Med 2014; 16:2910-8. [PMID: 22862818 PMCID: PMC4393719 DOI: 10.1111/j.1582-4934.2012.01611.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Accepted: 07/16/2012] [Indexed: 11/26/2022] Open
Abstract
Cardiac transverse (t)-tubules are altered during disease and may be regulated by stretch-sensitive molecules. The relationship between variations in the degree and duration of load and t-tubule structure remains unknown, as well as its implications for local Ca2+-induced Ca2+ release (CICR). Rat hearts were studied after 4 or 8 weeks of moderate mechanical unloading [using heterotopic abdominal heart–lung transplantation (HAHLT)] and 6 or 10 weeks of pressure overloading using thoracic aortic constriction. CICR, cell and t-tubule structure were assessed using confocal-microscopy, patch-clamping and scanning ion conductance microscopy. Moderate unloading was compared with severe unloading [using heart-only transplantation (HAHT)]. Mechanical unloading reduced cardiomyocyte volume in a time-dependent manner. Ca2+ release synchronicity was reduced at 8 weeks moderate unloading only. Ca2+ sparks increased in frequency and duration at 8 weeks of moderate unloading, which also induced t-tubule disorganization. Overloading increased cardiomyocyte volume and disrupted t-tubule morphology at 10 weeks but not 6 weeks. Moderate mechanical unloading for 4 weeks had milder effects compared with severe mechanical unloading (37% reduction in cell volume at 4 weeks compared to 56% reduction after severe mechanical unloading) and did not cause depression and delay of the Ca2+ transient, increased Ca2+ spark frequency or impaired t-tubule and cell surface structure. These data suggest that variations in chronic mechanical load influence local CICR and t-tubule structure in a time- and degree-dependent manner, and that physiological states of increased and reduced cell size, without pathological changes are possible.
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Affiliation(s)
- Michael Ibrahim
- Heart Science Centre, National Heart and Lung Institute, Imperial College London, London, UK
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36
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Abstract
Despite declines in heart failure morbidity and mortality with current therapies, rehospitalization rates remain distressingly high, substantially affecting individuals, society, and the economy. As a result, the need for new therapeutic advances and novel medical devices is urgent. Disease-related left ventricular remodeling is a complex process involving cardiac myocyte growth and death, vascular rarefaction, fibrosis, inflammation, and electrophysiological remodeling. Because these events are highly interrelated, targeting a single molecule or process may not be sufficient. Here, we review molecular and cellular mechanisms governing pathological ventricular remodeling.
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37
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Xenon and isoflurane reduce left ventricular remodeling after myocardial infarction in the rat. Anesthesiology 2013; 118:1385-94. [PMID: 23364599 DOI: 10.1097/aln.0b013e31828744c0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Xenon and isoflurane are known to have cardioprotective properties. We tested the hypothesis that these anesthetics positively influence myocardial remodeling 28 days after experimental perioperative myocardial infarction and compared their effects. METHODS A total of 60 male Sprague-Dawley rats were subjected to 60 min of coronary artery occlusion and 120 min of reperfusion. Prior to ischemia, the animals were randomized for the different narcotic regimes (0.6 vol% isoflurane, 70 vol% xenon, or intraperitoneal injection of s-ketamine). Acute injury was quantified by echocardiography and troponin I. After 4 weeks, left ventricular function was assessed by conductance catheter to quantify hemodynamic compromise. Cardiac remodeling was characterized by quantification of dilatation, hypertrophy, fibrosis, capillary density, apoptosis, and expression of fetal genes (α/β myosin heavy chains, α-skeletal actin, periostin, and sarco/endoplasmic reticulum Ca2+-ATPase). RESULTS Whereas xenon and isoflurane impeded the acute effects of ischemia-reperfusion on hemodynamics and myocardial injury at a comparable level, differences were found after 4 weeks. Xenon in contrast to isoflurane or ketamine anesthetized animals demonstrated a lower remodeling index (0.7 ± 0.1 vs. 0.9 ± 0.3 and 1.0 ± 0.3g/ml), better ejection fraction (62 ± 9 vs. 49 ± 7 and 35 ± 6%), and reduced expression of β-myosin heavy chain and periostin. The effects on hypertrophy, fibrosis, capillary density, and apoptosis were comparable. CONCLUSIONS Compared to isoflurane and s-ketamine, xenon limited progressive adverse cardiac remodeling and contractile dysfunction 28 days after perioperative myocardial infarction.
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Didié M, Biermann D, Buchert R, Hess A, Wittköpper K, Christalla P, Döker S, Jebran F, Schöndube F, Reichenspurner H, El-Armouche A, Zimmermann WH. Preservation of left ventricular function and morphology in volume-loaded versus volume-unloaded heterotopic heart transplants. Am J Physiol Heart Circ Physiol 2013; 305:H533-41. [PMID: 23771692 DOI: 10.1152/ajpheart.00218.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Total mechanical unloading of the heart in classical models of heterotopic heart transplantation leads to cardiac atrophy and functional deterioration. In contrast, partial unloading of failing human hearts with left ventricular (LV) assist devices (LVADs) can in some patients ameliorate heart failure symptoms. Here we tested in heterotopic rat heart transplant models whether partial volume-loading (VL; anastomoses: aorta of donor to aorta of recipient, pulmonary artery of donor to left atrium of donor, superior vena cava of donor to inferior vena cava of recipient; n = 27) is superior to the classical model of myocardial unloading (UL; anastomoses: aorta of donor to aorta of recipient, pulmonary artery of donor to inferior vena cava of recipient; n = 14) with respect to preservation of ventricular morphology and function. Echocardiography, magnetic resonance imaging, and LV-pressure-volume catheter revealed attenuated myocardial atrophy with ~30% higher LV weight and better systolic contractile function in VL compared with UL (fractional area shortening, 34% vs. 18%; maximal change in pressure over time, 2,986 ± 252 vs. 2,032 ± 193 mmHg/s). Interestingly, no differences in fibrosis (Picrosirus red staining) or glucose metabolism (2-[18F]-fluoro-2-deoxy-D-glucose-PET) between VL and UL were observed. We conclude that the rat model of partial VL attenuates atrophic remodelling and shows superior morphological as well as functional preservation, and thus should be considered more widely as a research model.
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Affiliation(s)
- Michael Didié
- Institute of Pharmacology, University Medical Center Göttingen and Deutsches Zentrum für Herz-Kreislauf-Forschung, partner site Göttingen, Germany
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Drakos SG, Wever-Pinzon O, Selzman CH, Gilbert EM, Alharethi R, Reid BB, Saidi A, Diakos NA, Stoker S, Davis ES, Movsesian M, Li DY, Stehlik J, Kfoury AG. Magnitude and time course of changes induced by continuous-flow left ventricular assist device unloading in chronic heart failure: insights into cardiac recovery. J Am Coll Cardiol 2013; 61:1985-94. [PMID: 23500219 DOI: 10.1016/j.jacc.2013.01.072] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 12/12/2012] [Accepted: 01/14/2013] [Indexed: 10/27/2022]
Abstract
OBJECTIVES This study sought to prospectively investigate the longitudinal effects of continuous-flow left ventricular assist device (LVAD) unloading on myocardial structure and systolic and diastolic function. BACKGROUND The magnitude, timeline, and sustainability of changes induced by continuous-flow LVAD on the structure and function of the failing human heart are unknown. METHODS Eighty consecutive patients with clinical characteristics consistent with chronic heart failure requiring implantation of a continuous-flow LVAD were prospectively enrolled. Serial echocardiograms (at 1, 2, 3, 4, 6, 9, and 12 months) and right heart catheterizations were performed after LVAD implant. Cardiac recovery was assessed on the basis of improvement in systolic and diastolic function indices on echocardiography that were sustained during LVAD turn-down studies. RESULTS After 6 months of LVAD unloading, 34% of patients had a relative LV ejection fraction increase above 50% and 19% of patients, both ischemic and nonischemic, achieved an LV ejection fraction ≥ 40%. LV systolic function improved as early as 30 days, the greatest degree of improvement was achieved by 6 months of mechanical unloading and persisted over the 1-year follow up. LV diastolic function parameters also improved as early as 30 days after LVAD unloading, and this improvement persisted over time. LV end-diastolic and end-systolic volumes decreased as early as 30 days after LVAD unloading (113 vs. 77 ml/m(2), p < 0.01, and 92 vs. 60 ml/m(2), p < 0.01, respectively). LV mass decreased as early as 30 days after LVAD unloading (114 vs. 95 g/m(2), p < 0.05) and continued to do so over the 1-year follow-up but did not reach values below the normal reference range, suggesting no atrophic remodeling after prolonged LVAD unloading. CONCLUSIONS Continuous-flow LVAD unloading induced in a subset of patients, both ischemic and nonischemic, early improvement in myocardial structure and systolic and diastolic function that was largely completed within 6 months, with no evidence of subsequent regression.
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Affiliation(s)
- Stavros G Drakos
- Utah Transplantation Affiliated Hospitals (UTAH) Cardiac Transplant Program, Divisions of Cardiology and Cardiothoracic Surgery, University of Utah Health Sciences Center, Intermountain Medical Center, Salt Lake City, Utah 84132, USA.
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Wang L, Xu YX, Du XJ, Sun QG, Tian YJ. Dynamic expression profiles of MMPs/TIMPs and collagen deposition in mechanically unloaded rat heart: implications for left ventricular assist device support-induced cardiac alterations. J Physiol Biochem 2013; 69:477-85. [PMID: 23315238 DOI: 10.1007/s13105-013-0235-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 01/02/2013] [Indexed: 11/25/2022]
Abstract
Left ventricular assist devices (LVADs) ameliorate heart failure by reducing preload and afterload. However, extracellular matrix (ECM) deposition after application of LVADs is not clearly defined. The purpose of the present study was to investigate ECM remodeling after mechanical unloading in a rat heart transplant model. Sixty male Lewis rats were subjected to abdominal heterotopic heart transplantation, and the transplanted hearts were pressure- and volume-unloaded. The age- and weight- matched male Lewis rats who had undergone open thoracic surgeries were used as the control. Left ventricle ECM accumulation and the expression/activity of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs) were measured on the third, seventh, and fourteenth days after transplantation/sham surgery. Compared with the control group, myocardial ECM deposition significantly increased on the seventh and fourteenth days after heart transplantation (P < 0.05) and peaked on the 14th day. The gelatinase activity as well as mRNA expression of MMP-2 and MMP-9 significantly increased after transplantation (P < 0.05). Both mRNA and protein levels of TIMP-1 and TIMP-2 significantly increased compared with those of the control group. Mechanical unloading may lead to adverse remodeling of the ECM of the left ventricle. The underlying mechanism may due to the imbalance of the MMP/TIMP system, especially the remarkable upregulation of TIMPs in the pressure and volume unloaded heart.
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Affiliation(s)
- Lu Wang
- Division of Cardiology, Shandong Corps Hospital of Chinese People's Armed Police Forces, Jinan, Shandong, People's Republic of China
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Heterotopic abdominal heart transplantation in rats for functional studies of ventricular unloading. J Surg Res 2013; 179:e31-9. [DOI: 10.1016/j.jss.2012.01.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 01/10/2012] [Accepted: 01/31/2012] [Indexed: 11/18/2022]
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Myokarderholung unter mechanischer Ventrikelentlastung und Entwöhnung vom ventrikulären Unterstützungssystem. ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2012. [DOI: 10.1007/s00398-012-0939-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Navaratnarajah M, Ibrahim M, Siedlecka U, van Doorn C, Shah A, Gandhi A, Dias P, Sarathchandra P, Yacoub MH, Terracciano CM. Influence of ivabradine on reverse remodelling during mechanical unloading. Cardiovasc Res 2012; 97:230-9. [DOI: 10.1093/cvr/cvs318] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
OPINION STATEMENT Advanced heart failure (HF) is a condition that is rarely thought of in terms of cure. Left ventricular assist devices (LVADs), like no therapy before them, provide complete decongestion of the left ventricle, with resulting favorable changes at all levels, from reversal of hypertrophy of cardiomyocytes to recovery of normal geometry and function of the ventricles. Although not a frequent phenomenon at most institutions, LV recovery is achieved in 20-25 % of LVAD recipients in some programs. Patients with good chances for recovery are usually young, with nonischemic cardiomyopathy and short duration of HF symptoms. After LVAD removal, patients with recovered function remain asymptomatic for years. To reach this level of sustainable restoration of cardiac function, several steps need to be taken: 1) myocardial recovery has to be recognized as a therapeutic goal, especially in patients with nonischemic cardiomyopathy; 2) HF medications have to be restarted and aggressively uptitrated after LVAD implantation; 3) regular monitoring for signs of myocardial recovery (eg, echocardiography or hemodynamics) should become a standard practice in LVAD centers; and 4) weaning protocols should be discussed and accepted at each LVAD program. While some protocols involve extensive several-day testing both at rest and with exercise, others are mostly guided by echocardiographic evaluation.
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Gao B, Chang Y, Gu K, Zeng Y, Liu Y. Physiological controller of an intra-aorta pump based on baroreflex sensitivity. Artif Organs 2012; 36:1015-25. [PMID: 22963124 DOI: 10.1111/j.1525-1594.2012.01511.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Left ventricular assist devices are increasingly used for long-term support in heart failure patients. It is important to find an optimum operating point for the pump that is appropriate for the existing function of the heart and the state of the circulatory system. Therefore, baroreflex sensitivity (BRS), as an indicator of heart function, is chosen as the control variable. In order to find an optimum point automatically, an extremum search algorithm (ESA) is designed to find an optimal mean arterial pressure (MAP), for which the BRS is maximum. Then, a MAP controller based on model-free adaptive control is designed to ensure that the measured MAP tracks the desired one. In order to test the feasibility of the control strategy, numerical simulations and simplified in vitro experiments were conducted. A mathematic model of the cardiovascular system simulating left ventricular failure, physical activity, and recovery of cardiac function is used in the simulation. The numerical simulations show that the maximum value of BRS can be found automatically by using ESA. The rotational speed of the pump is automatically increased (from 6500 rpm to 7000 rpm), and peripheral resistance is decreased to simulate slight physical activity. When E(max) is increased from 0.6 mm Hg/mL to 1.8 mm Hg/mL to mimic heart recovery, the speed is decreased from 7000 rpm to 6300 rpm in response. The optimum operating point for the pump can be detected by the proposed control strategy without the need to set a reference value for the control variable by operators.
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Affiliation(s)
- Bin Gao
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, China
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Drakos SG, Kfoury AG, Stehlik J, Selzman CH, Reid BB, Terrovitis JV, Nanas JN, Li DY. Bridge to recovery: understanding the disconnect between clinical and biological outcomes. Circulation 2012; 126:230-41. [PMID: 22777666 PMCID: PMC3714227 DOI: 10.1161/circulationaha.111.040261] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Stavros G Drakos
- Division of Cardiology, University of Utah School of Medicine, Salt Lake City, USA.
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Ibrahim M, Navaratnarajah M, Siedlecka U, Rao C, Dias P, Moshkov AV, Gorelik J, Yacoub MH, Terracciano CM. Mechanical unloading reverses transverse tubule remodelling and normalizes local Ca(2+)-induced Ca(2+)release in a rodent model of heart failure. Eur J Heart Fail 2012; 14:571-80. [PMID: 22467752 PMCID: PMC3359860 DOI: 10.1093/eurjhf/hfs038] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AIMS Ca(2+)-induced Ca(2+) release (CICR) is critical for contraction in cardiomyocytes. The transverse (t)-tubule system guarantees the proximity of the triggers for Ca(2+) release [L-type Ca(2+) channel, dihydropyridine receptors (DHPRs)] and the sarcoplasmic reticulum Ca(2+) release channels [ryanodine receptors (RyRs)]. Transverse tubule disruption occurs early in heart failure (HF). Clinical studies of left ventricular assist devices in HF indicate that mechanical unloading induces reverse remodelling. We hypothesize that unloading of failing hearts normalizes t-tubule structure and improves CICR. METHODS AND RESULTS Heart failure was induced in Lewis rats by left coronary artery ligation for 12 weeks; sham-operated animals were used as controls. Failing hearts were mechanically unloaded for 4 weeks by heterotopic abdominal heart transplantation (HF-UN). HF reduced the t-tubule density measured by di-8-ANEPPS staining in isolated left ventricular myocytes, and this was reversed by unloading. The deterioration in the regularity of the t-tubule system in HF was also reversed in HF-UN. Scanning ion conductance microscopy showed the reappearance of normal surface striations in HF-UN. Electron microscopy revealed recovery of normal t-tubule microarchitecture in HF-UN. L-type Ca(2+) current density, measured using whole-cell patch clamping, was reduced in HF but unaffected by unloading. The variance of the time-to-peak of the Ca(2+) transient, an index of CICR dyssynchrony, was increased in HF and normalized by unloading. The increased Ca(2+) spark frequency observed in HF was reduced in HF-UN. These results could be explained by the recoupling of orphaned RyRs in HF, as indicated by immunofluorescence. CONCLUSIONS Our data show that mechanical unloading of the failing heart reverses the pathological remodelling of the t-tubule system and improves CICR.
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Affiliation(s)
- Michael Ibrahim
- Laboratory of Cell Electrophysiology, Harefield Heart Science Centre, Imperial College London, London, UK
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Abstract
The use of left ventricular assist devices to induce substantial myocardial recovery with explantation of the device, bridge to recovery (BTR), is an exciting but currently grossly underused application. Recently acquired knowledge relating to BTR and its mechanisms offers unprecedented opportunities to streamline its use and unravel some of the secrets of heart failure with much wider implications. This article reviews the status, challenges, and future of cardiac recovery.
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Affiliation(s)
- Michael Ibrahim
- Heart Science Centre, Magdi Yacoub Institute, Harefield Hospital, London, UK
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Effective ventricular unloading by left ventricular assist device varies with stage of heart failure: cardiac simulator study. ASAIO J 2012; 57:407-13. [PMID: 21817896 DOI: 10.1097/mat.0b013e318229ca8d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Although the use of left ventricular assist devices (LVADs) as a bridge-to-recovery (BTR) has shown promise, clinical success has been limited due to the lack of understanding the timing of implantation, acute/chronic device setting, and explantation. This study investigated the effective ventricular unloading at different heart conditions by using a mock circulatory system (MCS) to provide a tool for pump parameter adjustments. We tested the hypothesis that effective unloading by LVAD at a given speed varies with the stage of heart failure. By using a MCS, systematic depression of cardiac performance was obtained. Five different stages of heart failure from control were achieved by adjusting the pneumatic systolic/diastolic pressure, filling pressure, and systemic resistance. The Heart Mate II® (Thoratec Corp., Pleasanton, CA) was used for volumetric and pressure unloading at different heart conditions over a given LVAD speed. The effective unloading at a given LVAD speed was greater in more depressed heart condition. The rate of unloading over LVAD speed was also greater in more depressed heart condition. In conclusion, to get continuous and optimal cardiac recovery, timely increase in LVAD speed over a period of support is needed while avoiding the akinesis of aortic valve.
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