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

Abstract

BACKGROUND Sudden death is a well-recognized complication of heart transplantation. Little is known about the incidence and risk factors for sudden death following transplant in children. The purpose of this study was to determine the incidence of and risk factors for sudden death. METHODS Retrospective multi-center cohort study using the Pediatric Heart Transplant Study Group (PHTS) database, an event driven registry of children <18 years of age 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 2491 children who underwent heart transplantation, 604 died of which 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 per year. Multivariate risk factors associated with sudden death include black race (HR 2.6; p<0.0001), UNOS Status 2 at transplant (HR 1.8; p=0.008), older age (HR 1.4 per 10 years of age; p=0.03), and an increased number of rejection episodes in the first post-transplant year (HR 1.6 per episode; p=0.03). CONCLUSION Sudden death accounts for one in six 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 one or more of these risk factors may benefit from primary prevention efforts.

Sudden death in children with cardiac allograft vasculopathy

“…This differs from prior studies in both adult and pediatric heart transplant recipients, which have shown an association between acute cellular rejection and sudden death [7,10,15]. Our study may not have found an association between rejection episodes and sudden death given our small sample size and the fact that our cohort as a whole did not have a high prevalence of either acute cellular or antibody mediated rejection.…”

“…The proportion of sudden death in our study cohort, 24%, is similar to prior studies, where sudden death was reported in 16-29% of heart transplant deaths [7,8,10]. To our knowledge, the hemodynamic differences we have shown between the SD group and the HFD/retransplant group are the first to be published in the literature.…”

“…That study did not find an association between CAV and sudden death, but the study authors concluded that the limitations of the registry data collection itself, as well as the low prevalence of CAV in that study cohort may have contributed to the inability to find an association [7]. A more recent study from the Pediatric Heart Transplant Study data demonstrated that the presence of an ejection fraction (EF) of <45%, a right atrial pressure of >12 mmHg, or a pulmonary capillary wedge pressure (PCWP) >15 mmHg put children at increased risk of graft loss despite mild angiographic CAV [8].…”

“…The data in the pediatric heart transplant population is more limited, although there have been registry studies demonstrating that sudden death occurred in 16% of all heart transplant deaths in children [7]. That study did not find an association between CAV and sudden death, but the study authors concluded that the limitations of the registry data collection itself, as well as the low prevalence of CAV in that study cohort may have contributed to the inability to find an association [7].…”

Cardiac Arrest and Sudden Cardiac Death in the Pediatric Population

“…Sudden death occurs in 1 out of 6 pediatric heart transplant recipients [34]. Factors associated with sudden death include: older recipient age, black race, and recurrent rejection within 1 year of age [33]. The development of cardiac allograft vasculopathy (CAV) accounts for approximately 14% of cases of death following pediatric heart transplantation [34].…”