Late rejection episodes more than 1 year after pediatric heart transplantation: Risk factors and outcomes

Background: Little is known about late rejection episodes after pediatric heart transplantation. We determined the frequency of late rejection episodes (>1 year) after pediatric heart transplantation, defined risk factors for its occurrence, and evaluated outcome after late rejection. Methods: We analyzed data from 685 pediatric recipients (<18 years at transplantation) who underwent transplantation between January 1, 1993, and December 31, 1997, at 18 centers in the Pediatric Heart Transplant Study (PHTS). Probability of freedom from late rejection was determined and risk factors for late rejection and for death after late rejection were sought using univariate and multivariate analyses. Results: We followed 431 patients for >1 year (median follow-up, 32.9 months) of whom 106 (24.6%) experienced 1 or more late rejection episodes (total of 178 episodes, 27 with severe hemodynamic compromise). Probability of freedom from first late rejection was 73% at 3 years and 66% at 4 years after transplantation. Risk factors (multivariate analysis) for first late rejection were >1 episode of rejection in the first year (p = 0.009), recipient black race (p = 0.0002), and older age at transplantation (P = 0.0003). Only 4 of 325 (1.2%) children who survived beyond 1 year without late rejection died compared with 26 of 106 (24.6%) with late rejection (P < 0.0001). Nine of these 26 died within 1 month of the first late rejection episode, and 17 died subsequently: 5 of acute rejection, 3 of sudden unexplained deaths, 3 of documented coronary artery disease, and 6 of other causes. Severe hemodynamic compromise with late rejection was identified as a risk factor for death among children with 1 or more episodes of late rejection. Conclusions: Approximately 25% of pediatric recipients in the PHTS who survived beyond 1 year experienced late rejection episodes. Late rejection is associated with poor survival, especially when associated with hemodynamic compromise. Absence of late rejection episodes is associated with very low risk of death during medium-term follow-up after pediatric heart transplantation. Determining the risk factors for late rejection will help to identify a cohort of patients who may benefit from enhanced rejection surveillance and treatment.