Favorable outcomes after heart transplantation in Barth syndrome

Barth Syndrome (BTHS) is a rare, X-linked disease characterized by cardioskeletal myopathy and neutropenia. Comparative outcomes after heart transplantation have not been reported.

We identified BTHS recipients across 3 registries (Pediatric Heart Transplant Study Registry [PHTS], Barth Syndrome Research Registry and Repository, and Scientific Registry of Transplant Recipient-Pediatric Health Information System) and matched them 1:4 to non-BTHS, male heart transplant (HT) recipients listed with dilated cardiomyopathy in PHTS. Demographics and survival data were analyzed for all recipients, whereas post-HT infection, malignancy, allograft vasculopathy, and acute rejection were only available for analysis for individuals with PHTS data.

Forty-seven BTHS individuals with 51 listings and 43 HTs (including 2 re-transplants) were identified. Age at primary HT was 1.7 years (IQR: 0.6-4.5). Mechanical circulatory support at HT was common (ventricular assist device 29%, extracorporeal membrane oxygenation 5%). Over a median follow-up of 4.5 years (IQR 2.7-9.1), survival for BTHS HT recipients was no different than non-BTHS HT recipients (HR 0.91, 95% CI 0.40-2.12, p = 0.85). Among those with PHTS data (n = 28), BTHS HT recipients showed no difference in freedom from infection (HR 0.64, 0.34-1.22; p = 0.18), malignancy (HR 0.22, 0.02-2.01, p = 0.18), and allograft vasculopathy (HR 0.58, 0.16-2.1, p = 0.41). Freedom from acute rejection (HR 0.39, 0.17-0.86, p = 0.02) was greater for BTHS HT recipients despite similar use of induction (61 vs 73%, p = 0.20), steroids at 30-days (75 vs 62%, p = 0.27), and dual/triple drug immunosuppression at 1-year (80 vs 84%, p = 0.55).

In this largest cohort yet reported, individuals with BTHS have equivalent survival with less acute rejection and no difference in infection or malignancy after HT. When indicated, HT for individuals with BTHS is appropriate.