Abstract 6072: Waitlist Mortality for Infants Awaiting Heart Transplantation in the United States in the Current Era: Analysis of Data from the United Network for Organ Sharing

Abstract

BACKGROUND UNOS (United Network for Organ Sharing) data suggest that of all pediatric transplant candidates, infants awaiting heart transplantation face the highest waitlist mortality. We sought to determine the mortality rate for waitlisted infants in the current era and to identify the risk factors associated with waitlist mortality. METHODS In this multi-center cohort study using the US Scientific Registry of Transplant Recipients, we analyzed all infants <12 months of age listed for first heart transplant between January 1999 and July 2006. Clinical and demographic characteristics were recorded at the time of listing. Multivariate logistic regression modeling was used to identify predictors of waitlist mortality. RESULTS In this six year period, 1133 patients less than 12 months of age were identified with a median age of 1 month (IQR 0 to 5 mo) and median weight of 4.0 kg (IQR 3.2 to 5.6 kg). 516 (45%) were female, 438 (39%) were non-white, 724 (64%) had congenital heart disease (CHD) and 910 (80%) were listed status 1A. Overall, 250 (22%) died while waiting including 179 (72%) listed at age <3 mo, 190 (76%) with CHD, 89 (35%) listed on mechanical ventilation, and 68 (27%) on ECMO. In multivariate analysis, risk factors for waitlist mortality (reported as hazard ratio, 95% CI) included age <3 months (1.5, 1.1–2.0), CHD (2.0, 1.5–2.7), ventilator support (2.0, 1.5–2.7), ECMO support (5.0, 3.6 –7.0) and non-white race (1.7, 1.4 –2.2). CONCLUSION Mortality of infants waiting for heart transplantation remains high with a 22% waitlist mortality in the current era. ECMO support, ventilator support, CHD, age less than 3 months, and non-white race were independently associated with waitlist mortality whereas listing status was not. Measures to improve donor availability for this age group and refinements in organ allocation to lower waitlist mortality are urgently needed.