The Registry of the International Society for Heart and Lung Transplantation: Thirty-fourth Adult Heart Transplantation Report—2017; Focus Theme: Allograft ischemic time

Aims Naturally secreted nanovesicles known as exosomes are required for the regenerative effects of cardiosphere-derived cells (CDCs), and exosomes mimic the benefits of CDCs in rodents. Nevertheless, exosomes have not been studied in a translationally realistic large-animal model. We sought to optimize delivery and assess the efficacy of CDC-secreted exosomes in pig models of acute (AMI) and convalescent myocardial infarction (CMI).

Methods and results In AMI, pigs received human CDC exosomes (or vehicle) by intracoronary (IC) or open-chest intramyocardial (IM) delivery 30 min after reperfusion. No-reflow area and infarct size (IS) were assessed histologically at 48 h. Intracoronary exosomes were ineffective, but IM exosomes decreased IS from 80 ± 5% to 61 ± 12% ( P = 0.001) and preserved left ventricular ejection fraction (LVEF). In a randomized placebo-controlled study of CMI, pigs 4 weeks post-myocardial infarction (MI) underwent percutaneous IM delivery of vehicle ( n = 6) or CDC exosomes ( n = 6). Magnetic resonance imaging (MRI) performed before and 1 month after treatment revealed that exosomes (but not vehicle) preserved LV volumes and LVEF (−0.1 ± 2.2% vs. −5.4 ± 3.6%, P = 0.01) while decreasing scar size. Histologically, exosomes decreased LV collagen content and cardiomyocyte hypertrophy while increasing vessel density.

Conclusion Cardiosphere-derived cell exosomes delivered IM decrease scarring, halt adverse remodelling and improve LVEF in porcine AMI and CMI. While conceptually attractive as cell-free therapeutic agents for myocardial infarction, exosomes have the disadvantage that IM delivery is necessary.

[10.1093/eurheartj/ehw324][1]

 [1]: /lookup/doi/10.1093/eurheartj/ehw324

/pdf/exosomes-secreted-by-cardiosphere-derived-cells-reduce-4e899awqkt.pdf

Exosomes secreted by cardiosphere-derived cells reduce scarring, attenuate adverse remodelling, and improve function in acute and chronic porcine myocardial infarction.

Exosomes are extracellular vesicles of endosomal origin which have emerged as key mediators of intercellular communication. All major cardiac cell types-including cardiomyocytes, endothelial cells, and fibroblasts-release exosomes that modulate cellular functions. Exosomes released from human cardiac progenitor cells (CPCs) are cardioprotective and improve cardiac function after myocardial infarction to an extent comparable with that achieved by their parent cells. Cardiac progenitor cell-derived exosomes are enriched in cardioprotective microRNAs, particularly miR-146a-3p. Circulating exosomes mediate remote ischaemic preconditioning. Moreover, they currently are being investigated as diagnostic markers. The discovery that cell-derived extracellular signalling organelles mediate the paracrine effects of stem cells suggests that cell-free strategies could supplant cell transplantation. This review discusses emerging roles of exosomes in cardiovascular physiology, with a focus on cardioprotective activities of CPC-derived exosomes.

Roles of exosomes in cardioprotection.

Background:Cardiosphere-derived cells (CDCs) confer cardioprotection in acute myocardial infarction by distinctive macrophage (Mϕ) polarization. Here we demonstrate that CDC-secreted exosomes (CDCe...

Exosomal MicroRNA Transfer Into Macrophages Mediates Cellular Postconditioning

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

/pdf/2019-eacts-expert-consensus-on-long-term-mechanical-3z1bknxdvb.pdf

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Fibroblasts Rendered Antifibrotic, Antiapoptotic, and Angiogenic by Priming With Cardiosphere-Derived Extracellular Membrane Vesicles.

Background The Organ Care System, an ex-vivo heart perfusion platform, represents an alternative to the current standard of cold organ storage that sustains the donor heart in a near-physiologic state. It is unknown whether using the Organ Care System influences 2-year outcomes after heart transplantation. We reviewed our institutional experience to compare 2-year outcomes for patients randomized to the Organ Care System or standard cold storage. Methods Between 2011 and 2013, heart transplant candidates from a single tertiary-care medical center enrolled within the PROCEED II trial were randomized to either standard cold storage or the Organ Care System. Outcomes assessed included 2-year survival, freedom from cardiac allograft vasculopathy (CAV), non-fatal major cardiac events (NF-MACE), biopsy-proven cellular rejection (CMR) and biopsy-proven antibody-mediated rejection (AMR). Results Thirty-eight patients were randomized to the Organ Care System ( n = 19) or cold storage group ( n = 19). There was no significant difference in 2-year patient survival (Organ Care System: 72.2%; cold storage: 81.6%; p = 0.38). Similarly, there were no differences in freedom from CAV, NF-MACE, CMR or AMR. The Organ Care System group had significantly longer total ischemia time (361 ± 96 minutes vs 207 ± 50 minutes; p p Conclusion The Organ Care System did not appear to be associated with significant differences in intermediate results compared with conventional strategies. These results suggest that this ex-vivo allograft perfusion system is a promising and valid platform for donor heart transportation.

Intermediate outcomes with ex-vivo allograft perfusion for heart transplantation.

Self-assembling heart-derived stem cell clusters named cardiospheres (CSps) improve function and attenuate remodeling in rodent models of acute myocardial infarction. The effects of CSps in chronically remodeled myocardium post-MI, and the underlying mechanisms, remain unknown. One month after permanent coronary ligation, rats were randomly assigned to injection of vehicle (controls) or CSps in the peri-infarct area. One month post-injection, CSps increased left ventricular function, reduced scar mass and collagen density, and enhanced vascularity within the infarct zone compared to controls. Immunoblots revealed Tgfβ-1/smad cascade downregulation and an increase in soluble endoglin post-CSp injection. Six months post-transplantation, left ventricular function further improved and cardiomyocyte hypertrophy was attenuated in the CSp-treated group. In vitro, co-culture of CSps with fibroblasts recapitulated the suppression of the Tgf-β1/smad pathway changes, responses which were blunted by neutralizing antibody against endoglin. Thus, cardiosphere transplantation enhances angiogenesis and reduces fibrosis in chronically infarcted myocardium, leading to partial reversal of cardiac dysfunction. The underlying mechanism involves inhibition of Tgf-β1/smad signaling by CSp-secreted soluble endoglin.

Cardiospheres reverse adverse remodeling in chronic rat myocardial infarction: roles of soluble endoglin and Tgf-β signaling

Purpose Combined heart-liver transplantation is an increasingly accepted treatment for select patients with heart and liver disease. Despite growing optimism, heart-liver transplantation remains an infrequent operation. We report our institutional experience with heart-liver transplantation. Methods All combined heart-liver transplantations at Cedars-Sinai Medical Center from 1998–2014 were analyzed. Primary outcomes were patient and graft survival and secondary outcomes included rejection, infection, reoperation, length of stay, and readmission. Results There were 7 heart-liver transplants: 6 simultaneous (single donor) and 1 staged (2 donors). Median follow-up was 22.1 (IQR 13.2–48.4) months. Mean recipient age was 50.8 ± 19.5 years. Heart failure etiologies included familial amyloidosis, congenital heart disease, hypertrophic cardiomyopathy, systemic lupus erythematosus, and dilated cardiomyopathy. Preoperative left ventricular ejection fraction averaged 32.3 ± 12.9%. Five (71.4%) patients required preoperative inotropic support; 1 required mechanical circulatory support. The most common indications for liver transplant were amyloidosis and cardiac cirrhosis. Median Model for End-stage Liver Disease score was 10.0 (9.3–13.8). Six-month and 1-year actuarial survivals were 100% and 83.3%, with mean survival exceeding 4 years. No patient experienced cardiac allograft rejection, 1 experienced transient liver allograft rejection, and 1 developed progressive liver dysfunction resulting in death. Five developed postoperative infections and 3 (42.9%) required reoperation. Median ICU and hospital stays were 7.0 (7.0–11.5) and 17.0 (13.8–40.5) days. There were 4 (57.1%) readmissions. Conclusions For carefully selected patients with coexisting heart and liver disease, combined heart and liver transplantation offers acceptable patient and graft survival.

Combined Heart and Liver Transplantation: The Cedars-Sinai Experience.

Using older donor hearts in cardiac transplantation may lead to inferior outcomes: older donors have more comorbidities that reduce graft quality, including coronary artery disease, hypertension, diabetes mellitus, and dyslipidemia. Shorter cold ischemic times might overcome the detrimental effect of older donor age. We examined the relationship between donor allograft age and cold ischemic time on the long-term outcomes of heart transplant recipients. rom 1994 through 2010, surgeons at our hospital performed 745 heart transplantations. We retrospectively classified these cases by donor ages of 240 min (long). Endpoints included recipient and graft survival, and freedom from cardiac allograft vasculopathy, nonfatal major adverse cardiac events, and rejection. For intermediate ischemic times, the 5-year recipient survival rate was lower when donors were older (70% vs 82.6%; P=0.02). This was also true for long ischemic times (69.8% vs 87.6%; P=0.09). For short ischemic times, we found no difference in 5-year recipient or graft survival rates (80% older vs 85.6% younger; P=0.79), in freedom from nonfatal major adverse cardiac events (83.3% vs 91.5%; P=0.46), or in freedom from cardiac allograft vasculopathy (50% vs 70.6%; P=0.66). Rejection rates were mostly similar. Long-term graft survival in heart transplantation patients with older donor allografts may improve when cold ischemic times are shorter.

Heidi Reich

Papers

Fibroblasts Rendered Antifibrotic, Antiapoptotic, and Angiogenic by Priming With Cardiosphere-Derived Extracellular Membrane Vesicles.

Intermediate outcomes with ex-vivo allograft perfusion for heart transplantation.

Cardiospheres reverse adverse remodeling in chronic rat myocardial infarction: roles of soluble endoglin and Tgf-β signaling

Combined Heart and Liver Transplantation: The Cedars-Sinai Experience.

Effects of Older Donor Age and Cold Ischemic Time on Long-Term Outcomes of Heart Transplantation.