Abstract 16940: Heart Transplant After Failed Single Ventricle Palliation in Young Infants Carries Excess Mortality Risk: A Multi-Institutional Study

Abstract

BACKGROUND: Infant heart transplant (HT) recipients have the best long term survival of any age group, but small donor pool and high early mortality limit the therapeutic efficacy. We aimed to determine the relationship between pre-HT diagnosis and early HT outcome to identify infants most likely to benefit from HT. METHODS: The Pediatric Heart Transplant Study (PHTS) database was used to identify 739 infants s/p HT at age ≤6 mths between 1993-2008 divided into the following etiologic groups: cardiomyopathy (CM: 132, 18%); hypoplastic left heart syndrome without prior surgery (HLHS_WOS: 303, 41%); HLHS with surgery (HLHS_WS: 69, 9%); other congenital heart disease without surgery (CHD_WOS: 121, 16%; and other congenital heart disease with surgery (CHD_WS: 114, 15%). Severity of illness at HT, post HT survival, and era effects were compared among the 4 groups. RESULTS: The 1 yr survival for HLHS_WOS (79%) was similar to CHD_WOS (79%) and CHD_WS (82%) but worse than CM (89%). HLHS_WS had the highest mortality w 1 yr survival of 70%, p=0.03. Hazard function analysis showed the difference occurred within the 1st 6 mths after HT. Survival remained poor in the current surgical era for HLHS_WS, 71% (1993-1998) v 70% (1999-2008). Risk factors at HT associated w mortality included age <1 mth (OR 2.5; CI 1.3-4.7, p=0.01), ECMO (OR 3.7; CI 2-6.8, p<0.01), ventilator use (OR 1.8; CI 1-3.2, p=0.04), and HLHS_WS (OR 2.3; CI 1.3-4.1, p<0.01). After adjusting for illness severity, differences in mortality risk persisted across etiologic groups. HLHS_WS (HR 2.3, CI 1.3-4, P<0.01), CHD_WOS (HR 1.8, 1.1-3.1, P= 0.03), and HLHS_WOS (HR 1.7, 1.1-2.8, P=0.02) had significantly higher risk for mortality compared to CM. CONCLUSIONS: Infant HT recipients with different pre-HT diagnoses have strikingly different outcomes after HT that are unchanged over time and seem unrelated to clinical acuity at HT. CM infants have excellent survival, but HLHS_WS represent a high risk group for early mortality after HT.