Sudden death after pediatric heart transplantation: analysis of data from the Pediatric Heart Transplant Study Group.

Background: Sudden death is a well-recognized complication of heart transplantation. Little is known about the incidence and risk factors for sudden death after transplant in children. The purpose of this study was to determine the incidence of and risk factors for sudden death.

Methods: This retrospective multicenter cohort study used the Pediatric Heart Transplant Study Group (PHTS) database, an event-driven registry of children aged <18 at listing undergoing heart transplantation between 1993 and 2007. Standard Kaplan-Meier and parametric analyses were used for survival analysis. Multivariate analysis in the hazard-function domain was used to identify risk factors for sudden death after transplant.

Results: Of 604 deaths in 2,491 children who underwent heart transplantation, 94 (16%) were classified as sudden. Freedom from sudden death was 97% at 5 years, and the hazard for sudden death remained constant over time at 0.01 deaths/year. Multivariate risk factors associated with sudden death included black race (hazard ratio [HR], 2.6; p < 0.0001), United Network of Organ Sharing (UNOS) status 2 at transplant (HR, 1.8; p = 0.008), older age (HR, 1.4/10 years of age; p = 0.03), and an increased number of rejection episodes in the first post-transplant year (HR, 1.6/episode; p = 0.03).

Conclusion: Sudden death accounts for 1 in 6 deaths after heart transplant in children. Older recipient age, recurrent rejection within the first year, black race, and UNOS status 2 at listing were associated with sudden death. Patients with 1 or more of these risk factors may benefit from primary prevention efforts.