Contemporary Waitlist and Post-Heart Transplant Outcomes for Fontan patients: An International Multi-Institutional Analysis.

BACKGROUND

Pediatric patients with Fontan circulation represent a growing, high-risk cohort of heart transplant (HT) candidates. However, contemporary multi-institutional data on their waitlist and post-transplant outcomes are limited.

METHODS

We conducted a retrospective analysis of children aged 2 to <18 years listed for HT in the Pediatric Heart Transplant Society database from 1993 to 2023. Patients were categorized as having Fontan circulation, non-Fontan congenital heart disease (CHD), or cardiomyopathy (CMP). Outcomes were analyzed across early (1993-2014) and current (2015-2023) eras. Cox proportional hazards models identified risk factors for waitlist mortality and post-transplant graft loss.

RESULTS

Among 6061 listed patients, 22.3% had Fontan circulation, 24.1% non-Fontan CHD, and 53.6% CMP. In the current era, 54.6% of CHD listings are Fontan patients. Fontan patients were significantly less likely to receive ventricular assist device (VAD) support at listing (2.6%) or transplant (4.7%) compared to CMP (16.4%, 29.5%; P < .001). Waitlist survival has improved significantly, with no differences among diagnostic groups in the current era (P = .109). However, Fontan patients had a 2-fold higher risk of post-transplant graft loss compared to CMP (HR 1.99, P < .0001) and experienced higher rates of post-transplant infection and malignancy (P < .05). Among Fontan patients, VAD-supported individuals had similar post-transplant survival to those without mechanical support and significantly better survival than those supported with extracorporeal membrane oxygenation (P < .0001).

CONCLUSIONS

Fontan patients now represent the largest CHD subgroup listed for HT. While waitlist outcomes have improved, posttransplant outcomes remain inferior. Selective and timely use of VAD support may improve survival in this high-risk population.