Heart Transplantation and Mechanical Circulatory Support in Adults with Congenital Heart Disease

Purpose of Review

To assess current management strategies for advanced heart failure in adults with congenital heart disease, including heart transplantation and mechanical circulatory support.

Recent Findings

Current data demonstrate that adults with CHD generally experience higher short-term mortality after heart transplantation and MCS implantation, but enjoy superior long-term survival. Such patients are nonetheless less likely to receive a transplant than non-ACHD peers due to a variety of factors, including lack of applicability of current listing criteria to HF in ACHD. MCS is underutilized in ACHD, but provides similar quality of life benefits for ACHD and non-ACHD patients alike.

Summary

Heart failure in ACHD is complex and difficult to treat, and both heart transplantation and mechanical circulatory support are often challenging to implement in this patient population. However, long-term results are encouraging, and existing data supports increasing use of MCS and transplant earlier in their disease course. Multidisciplinary care is critical to success in these complex patients.

     

Mechanical Circulatory Support in Pediatric and Adult Congenital Heart Disease

The use of ventricular-assist device (VAD) support continues to increase and it is now considered part of the standard of care for most adult and children with end-stage heart failure unresponsive to medical management. However, the application of VAD therapy in both the pediatric and adult population with congenital heart disease (CHD) has been less extensive and continues to face significant challenges. Nevertheless, the experience is growing and the use of VADs in the CHD population is no longer limited to case reports, thereby increasing our understanding of how best to support this diverse patient population. The current body of literature provides a framework to understand the outcomes of this unique patient population with respect to mortality, risk factors, and associated morbidities in both adult and pediatric patients with CHD. This review will summarize that body of literature with focus on outcomes based on device type and anatomy. We also highlight efforts made by the community to improve outcomes of patients with CHD on VAD support.     

Perioperative Management of Pulmonary Hypertension in Children with Critical Heart Disease

Pulmonary hypertension (PHTN) is common to a variety of conditions occurring in infants and children presenting to the intensive care unit. A fundamental understanding of the response of the right ventricle to an increase in afterload and the clinical syndromes responsible for PHTN is essential for managing patients with PHTN and critical heart disease. There are important distinguishing features between PHTN syndromes, and although one form of PHTN may predominate, often more than one mechanism of PHTN is contributing to the pathophysiologic state. Thus, it is imperative to tailor therapies accordingly in order to optimize outcomes.     

机械循环支持治疗心力衰竭的研究进展

目前终末期心力衰竭的治疗除药物和心脏移植外,主要依赖机械循环支持,后者自20世纪末出现以来,已取得了长足进步,应用领域从最初的心脏移植前过渡逐渐扩展到心力衰竭的长期支持乃至终点治疗.最新的机械循环支持以左心室辅助装置为主,包括主动脉内球囊反搏泵、体外膜肺及全人工心脏等.近年来,随着制造工艺和材料的革新,机械循环支持的适应证逐渐拓展,机械辅助治疗充血性心力衰竭的随机化评估、HeartMateⅡ终点治疗等大规模临床试验也验证了其在不同心力衰竭患者中的获益.随着应用例数的增加,临床证据日臻完善,但也逐渐浮现出诸如出血、感染、血栓、机械故障等并发症.这些问题的出现,对装置的植入时机、手术技术、术后维护提出了更高的要求.目前,机械循环支持系统的小型化、驱动系统的零接触化及新型生物材料的使用,推动了新一代设备的革新,使其向着便携式、简单化、持久耐用的方向发展,有望在未来完全替代心脏移植,成为心力衰竭的标准化治疗方案.     

Mechanical Circulatory Support for Advanced Heart Failure

Both acute and chronic systolic heart failure can progress to an advanced phase, resulting in stage D heart failure and even cardiogenic shock. Despite significant progress in the treatment of systolic heart failure using medical and device therapies, this terminal phase continues to be prevalent and associated with unacceptably high morbidity and mortality. Given the inability to offer cardiac transplantation to the majority of those presenting with advanced heart failure, alternative strategies for cardiac replacement therapy are often required. Although there has been interest in using mechanical devices to support the circulation since the advent of cardiopulmonary bypass, it is only in the past 20 years that ventricular assist devices (VAD) have become viable options for therapy. Indeed, we are now entering an era where circulatory assist devices are being used not only to temporarily support patients with post-cardiotomy shock, but also as a long-term treatment in ambulatory heart failure patients. Furthermore, we are now able to utilize data from multicenter trials and registries to guide treatment decisions. These data have clearly shown that VADs improve survival and quality of life in patients with advanced heart failure when implanted as a temporary measure (bridge to recovery and bridge to transplant) or as long-term support (destination therapy). However, with a growing heart failure population there is much work to be done to improve VAD technology, patient selection, post-implantation management, and to define the optimal role for assist devices in the management of systolic heart failure. We are also in the nascent stages of fully understanding the impact of mechanical support on the failing myocardium, and developing research methodologies to study novel therapies in tandem with VADs to facilitate ventricular recovery. These important questions are currently being addressed in ongoing clinical trials, registry analyses, and translational research endeavors.     

Survival After Heart Transplantation in Patients Bridged With Mechanical Circulatory Support

BackgroundThe United Network of Organ Sharing (UNOS) heart allocation policy designates patients on ECMO or with nondischargeable, surgically implanted, nonendovascular support devices (TCS-VAD) to higher listing statuses.ObjectivesThis study aimed to explore whether temporary circulatory support-ventricular assist devices (TCS-VAD) have a survival advantage over extracorporeal membrane oxygenation (ECMO) as a bridge to transplant.MethodsThe UNOS database was used to conduct a retrospective analysis of adult heart transplants performed in the United States between 2005 and 2017. Survival analysis was performed to compare patients bridged to transplant with different modalities.ResultsOf the 24,905 adult transplants performed, 7,904 (32%) were bridged with durable left ventricular assist devices (LVADs), 177 (0.7%) with ECMO, 203 (0.8%) with TCS-VAD, 44 (0.2%) with percutaneous endovascular devices, and 8 (0.03%) with TandemHeart (LivaNova, London, United Kingdom). Unadjusted survival at 1 and 5 years post-transplant was 90 ± 0.4% and 77 ± 0.7% for durable LVAD, 84 ± 3% and 71 ± 4% for all TCS-VAD types, 79 ± 9% and 73 ± 14% for biventricular TCS-VAD, and 68 ± 3% and 61 ± 8% for ECMO. After propensity-matched pairwise comparisons were made, survival after all TCS-VAD types continued to be superior to ECMO (p = 0.019) and similar to LVAD (p = 0.380). ECMO was a predictor of post-transplant mortality in the Cox analysis compared with TCS-VAD (hazard ratio 2.40; 95% confidence interval: 1.44 to 4.01; p = 0.001).ConclusionsPost-transplant survival with TCS-VAD is superior to ECMO and similar to LVAD in a national database.     

Evaluating Heart Failure After Implantation of Mechanical Circulatory Support Devices

The medical community has seen an explosive rise in the utilization of implantable mechanical circulatory support devices for late-stage cardiomyopathy. Care for these complex patients requires a basic understanding of device physiology and potential complications. This review focuses on an algorithm that incorporates a careful clinical history and examination with diagnostic modalities for the evaluation of a patient who is failing therapy with a continuous-flow left ventricular assist device, as well as the general management and optimization of patients implanted with an artificial heart.     

Mechanical Circulatory Support in Children: Bridge to Transplant Versus Recovery

The number of children and adolescents suffering from heart failure is increasing dramatically. Some of these patients will progress to need advanced therapies in the form of mechanical circulatory support (MCS). Over the past few years, increased attention has been focused on clinical use of existing devices as well the development of pediatric-specific ventricular assist devices (VADs). As in adult populations, these devices offer unique opportunities to successfully support children as a bridge-to-transplant, but increasing data suggest that bridge-to-recovery and bridge-to-destination are also viable options in select pediatric populations. Herein, we will review existing approaches as well describe future potential MCS options.     

Hospital to Home with Mechanical Circulatory Support

Mechanical circulatory support (MCS) is becoming the mainstay of therapy for patients with advanced heart failure, both for patients needing support as a bridge to transplantation and for those who require the device as a destination therapy. As more and more devices are implanted, there is a need to address effective discharge planning, arrange appropriate follow-up, anticipate and address complications, and develop strategies for long-term care. In this article, we will discuss issues surrounding discharge and challenges of managing patients with MCS in the outpatient setting.