Waiting List Mortality Among Children Listed for Heart Transplantation in the United States

TLDR

Children awaiting heart transplantation experience the highest waiting‑list mortality among solid‑organ transplants. The study aimed to assess whether the 1999 pediatric heart‑allocation revision optimally prioritizes patients and to identify high‑risk groups that could benefit from emerging assist devices. Researchers performed a multicenter cohort analysis of 3,098 children under 18 listed for heart transplant between 1999 and 2006 using the US Scientific Registry of Transplant Recipients. Seventeen percent of the cohort died, 63% received transplants, and 8% recovered, with ECMO, ventilator use, status 1A, congenital heart disease, dialysis, and nonwhite race emerging as independent mortality predictors, underscoring the inadequacy of the current allocation system and the need to target high‑risk subgroups.

Abstract

Children listed for heart transplantation face the highest waiting list mortality in solid-organ transplantation medicine. We examined waiting list mortality since the pediatric heart allocation system was revised in 1999 to determine whether the revised allocation system is prioritizing patients optimally and to identify specific high-risk populations that may benefit from emerging pediatric cardiac assist devices.We conducted a multicenter cohort study using the US Scientific Registry of Transplant Recipients. All children <18 years of age who were listed for a heart transplant between 1999 and 2006 were included. Among 3098 children, the median age was 2 years (interquartile range 0.3 to 12 years), and median weight was 12.3 kg (interquartile range 5 to 38 kg); 1294 (42%) were nonwhite; and 1874 (60%) were listed as status 1A (of whom 30% were ventilated and 18% were on extracorporeal membrane oxygenation). Overall, 533 (17%) died, 1943 (63%) received transplants, and 252 (8%) recovered; 370 (12%) remained listed. Multivariate predictors of waiting list mortality include extracorporeal membrane oxygenation support (hazard ratio [HR] 3.1, 95% confidence interval [CI] 2.4 to 3.9), ventilator support (HR 1.9, 95% CI 1.6 to 2.4), listing status 1A (HR 2.2, 95% CI 1.7 to 2.7), congenital heart disease (HR 2.2, 95% CI 1.8 to 2.6), dialysis support (HR 1.9, 95% CI 1.2 to 3.0), and nonwhite race/ethnicity (HR 1.7, 95% CI 1.4 to 2.0).US waiting list mortality for pediatric heart transplantation remains unacceptably high in the current era. Specific high-risk subgroups can be identified that may benefit from emerging pediatric cardiac assist technologies. The current pediatric heart-allocation system captures medical urgency poorly. Further research is needed to define the optimal organ-allocation system for pediatric heart transplantation.