Does the heart transplant have a future?

Abstract

Heart failure has remained the leading cause of death globally for the last 15 years-and its prevalence will continue to rise. Fifty years ago, heart failure management was enriched by the possibility of a heart transplant. Despite impressive improvements in medical treatment for heart failure, a heart transplant remains the most effective long-lasting treatment for advanced heart failure in terms of mortality and quality of life. However, donor and recipient characteristics have changed dramatically in recent years, leading to more complex decision-making regarding organ acceptance and to more demanding operations and postoperative management. With improving pathophysiological understanding in the last decades, today's scientific interest still focuses on basic knowledge. How to retrieve and conserve organs to minimize ischaemic injury; how best to allocate them, considering the likelihood of success (developing a heart-allocation scoring system similar to that for lung allocation); how to match donor/recipient characteristics (ABO blood-group antigen compatibility versus incompatibility); and how to avoid graft failure, rejection and secondary morbidities such as malignomas and cardiac allograft vasculopathy after the heart transplant-all these factors remain fundamental challenges in today's transplant medicine. The use of ex vivo perfusion (e.g. via the Organ Care System®, TransMedics, Andover, MA, USA) may play an important role in this change. Remarkably, there are huge regional divergences in current transplant practices: Whereas the number of transplants continues to rise in most Eurotransplant countries and other major transplant networks, there are some countries in which transplant numbers are static or even dropping (as in Germany). This difference results in wide variations across different countries as to how advanced heart failure is treated using mechanical circulatory-assist devices.

Keywords: Heart failure; Heart transplant; Long-term survival; Mechanical circulatory support.

Figure 1:

Prevalence of heart failure by sex and age (National Health and Nutrition Examination Survey, 2011–2014)—adopted and modified from Ref. [2].

Figure 2:

Parametric survival curve and associated hazard function with 70% confidence limit for survival after implantation of a continuous-flow LVAD or BiVAD. Reprinted with permission from Ref. [12]. BiVAD: biventricular assist device; LVAD: left ventricular assist device.

Figure 3:

Kaplan–Meier survival in adult heart transplant recipients by era (transplants: January 1982–June 2015). Reprinted with permission from Ref. [8].

Figure 4:

Survival rates in trials and registry reports of heart transplantation and chronic mechanical circulatory support as DT. Reprinted with permission from Ref. [48]. DT: lifetime therapy; HM: HeartMate; LVAD: left ventricular assist device; OMM: optimal medical management; VE/XVE: early generation ventricular assist devices (HeartMate VE/XVE, Thoratec Corp., Pleasanton, CA).

Figure 5:

(A) Number of adult and paediatric heart transplants by year (transplants: 1982–2015) and geographic region. Reprinted with permission from Ref. [8]. (B) Overview of new high-urgency registrations and total heart transplants 2004–2017 in Germany (data: Eurotransplant).

Figure 6:

Adult and paediatric heart transplants according to median donor age by location and year. Reprinted with permission from Ref. [8].