Cardiac Transplantation

Heart transplantation remains the definitive treatment of choice for patients with end-stage organ dysfunction. In the pediatric population, the indications include heart failure due to cardiomyopathy, congenital heart disease (CHD) not amenable to initial or further surgical repair, and cardiac allograft failure requiring retransplantation. Nearly 10, 000 pediatric heart transplants (pHTx) have been performed worldwide since the first successful (albeit short-term) pHTx was reported in 1968; currently more than 500 pHTx are performed annually.1, 2 As noted by the latest International Society for Heart and Lung Transplantation (ISHLT) Registry report, more than 500 pHTx are performed annually at 96 centers, with 56% located in North America, 41% in Europe, and 3% in the remainder of the world; nearly 50% of pHTx are performed in centers that perform more than 10 pHTx annually, and nearly half of pHTx centers in North America perform more than 10 heart transplants (both adults and pediatrics) annually.1 Early survival has improved over the last two decades, in large part due to improvements in perioperative care, particularly so in the case of infants or patients with structural CHD.3 The late outcomes remain relatively unchanged, however, since no therapy has been successful in addressing chronic rejection.4, 5 For infants (less than 1 year of age), the two most common indications for transplant are CHD (58%) and cardiomyopathy (39%) while for older children (more than 11 years of age), cardiomyopathy is more common (62%); for children between the ages of 1 and 10, cardiomyopathy accounts for 54% while CHD accounts for 39%.1 Retransplants account for 6% of all cases, with nearly half occurring more than 5 years after the initial transplant; 56% of cases occur in children above 10 years of age.1 There is some evidence that patients with cardiomyopathy have more favorable outcomes compared to other pHTx patient groups.6 Single institutional reports from centers with significant surgical experience with CHD, however, have demonstrated that patients who undergo pHTx for CHD have equivalent results to recipients with a preoperative diagnosis of cardiomyopathy.7-9 It is thought that CHD patients at these centers are likely to have favorable palliative CHD results, thereby making them better transplant candidates. Furthermore, CHD patients in the more recent era are more likely to have improved perioperative care compared to patients in previous eras. HLHS was a common indication for primary pHTx for more than 20 years, but since the late 1990s, this is been less prevalent as more favorable outcomes with staged palliation have been achieved at many centers.10, 11 In contrast, a large study recently noted that the combined pHTx wait list mortality and early post-pHTx mortality rate for HLHS patients was more than 50%.12.