Favorable Outcomes in Heart Transplantation for Dilated Cardiomyopathy Associated with Barth Syndrome
BACKGROUND: Barth Syndrome (BTHS) is a rare (~1/350,000), X-linked mitochondrial disease characterized by cardioskeletal myopathy and neutropenia. Reported outcomes after heart transplantation (HT) are limited to rare case reports and one case series. We sought to identify all listings and transplants in BTHS individuals and compare post-HT survival, infection and acute rejection (AR) to non-BTHS dilated cardiomyopathy (DCM).
METHODS: To identify BTHS listings and transplants we solicited data from the BTHS community (Barth Syndrome Registry and Repository, BRR) and from member-centers of the Pediatric Heart Transplant Society (PHTS). BTHS HT recipients in the Scientific Registry of Transplant Recipients (SRTR) were identified via ICD-10 diagnosis coding. To avoid recounting records occurring in >1 registry, we used years of birth, listing, and transplantation and listing/transplant city to link BTHS records across registries. BTHS HT recipients were matched up to 1:4 on age, transplant era, urgency status, and use of extracorporeal membrane oxygenation (ECMO)/ventricular assist device (VAD) at HT to male, non-BHTS DCM HT recipients in the PHTS. We used univariable Cox models to compare survival for all recipients and freedom from post-HT infection and AR in the subgroup of BTHS recipients for whom we had these data (i.e., those with PHTS data).
RESULTS: BTHS patients, listings, and transplants identified from each data source were: PHTS 27 patients/30 listings/24 transplants, SRTR 17 patients/18 transplants, and BRR 26 patients/28 listings/25 transplants. After linkage, 47 patients, 51 listings, and 43 transplants (including 2 re-transplants) were identified. Twenty-nine BTHS recipients had data in PHTS. Median age at HT was 1.9 years (IQR: 0.6-5.8) with 35% <1 years-old at HT. BTHS HT increased over time (14% in 1990-99, 30% in 2000-09, and 56% in 2010-18), consistent with the increase in HT for non-BTHS DCM (p=0.82). Mechanical circulatory support at HT was common (VAD 29%, ECMO 9%). Compared to matched controls, we observed no difference in post-HT survival (Figure 1). Freedom from overall infection and bacterial infection were similar between BTHS patients and controls, while AR was less common for BTHS (Figure 2).
CONCLUSION: We have identified the largest cohort of BTHS HT recipients. Given the rarity of BTHS, HT appears to be common in BTHS. Post-HT survival and infection risk are the same as non-BTHS DCM HT recipients, with a lower risk of acute rejection. These data strongly support that individuals with BTHS should not be excluded from HT solely on the diagnosis of BTHS.
Yu Li1, Justin Godown2, Carolyn Taylor3, Anne I Dipchand4, Brian Feingold1,
- University of Pittsburgh School of Medicine, Pittsburgh, PA
- Pediatric Cardiology, Monroe Carell Jr. Children's Hospital, Nashville, TN
- Medical University of South Carolina, Charleston, SC
- Hospital for Sick Children, University of Toronto, Toronto, ON, Canada