Effect of induction therapy on graft survival in primary pediatric heart transplantation: A propensity score analysis of the UNOS database

Background. The use of induction therapy in pediatric heart transplantation has increased. The aim of this study was to investigate the effects of induction therapy on graft survival. Methods. The United Network for Organ Sharing database was queried for isolated pediatric heart transplants from January 1, 1994, to December 31, 2013. Propensity scores for induction treatment were calculated by estimating probability of induction using a logistic regression model. Transplants were then matched between induction treatment groups based on the propensity score, reducing potential biases. Using only propensity scorematched transplants, the effect of induction therapy on graft survival was investigated using Cox-proportional hazards. Subgroup analyses were performed based on age, race, recipient cardiac diagnosis, HLA, and recipient panel-reactive antibody (PRA). Results. Of 4565 pediatric primary heart transplants from 1994 to 2013, 3741 had complete data for the propensity score calculation. There were 2792 transplants successfully matched (induction, n = 1396; no induction, n = 1396). There were no significant differences in transplant and pretransplant covariates between induction and no induction groups. In the Cox-proportional hazards model, the use of induction of was not associated with graft loss (hazard ratio [HR], 0.88; 95% confidence interval [95% CI], 0.75-1.01; P = 0.07). In subgroup analyses, induction therapy may be associated with improved survival in patients with PRA greater than 50% (HR, 0.57; 95% CI, 0.34-0.97) and congenital heart disease (HR, 0.78; 95% CI, 0.64-0.96). Conclusions. Induction therapy is not associated with improved graft survival in primary pediatric heart transplantation. However, in pediatric heart transplant recipients with PRA greater than 50% or congenital heart disease, induction therapy is associated with improved survival.