Kidney transplant outcomes in children with simultaneous versus sequential heart–kidney transplants

Background: Heart transplant recipients frequently require kidney transplantation for concomitant advanced chronic kidney disease. Data on simultaneous (heart and kidney transplants performed simultaneously) versus sequential (heart transplant performed before kidney) heart–kidney transplants in children are limited. Herein, we compare kidney transplant outcomes between the two groups. Method: We used the Scientific Registry of Transplant Recipients to identify all pediatric (age <21 years) heart transplant recipients who also received a kidney transplant within 10 years of the heart transplant. We divided the study cohort into simultaneous heart–kidney and sequential heart–kidney recipients. We compared patient and death-censored graft survival using the Cox regression, adjusting for age at kidney transplant, sex, race, pre-transplant dialysis, donor type, and prior kidney transplant. We evaluated delayed graft function (defined as dialysis within the first week posttransplant) using logistic regression. Results: Our analysis cohort included 165 recipients (86 simultaneous and 79 sequential). The incidence of delayed graft function was higher in simultaneous recipients (22.4 vs. 7.7%, p=0.017), but the difference lost statistical significance on multivariable analysis. We found no difference in patient survival (aHR 0.97; 95% CI 0.39, 2.41; p=0.95) after kidney transplant but higher death-censored kidney graft survival in sequential heart–kidney recipients compared with simultaneous heart–kidney recipients (aHR 4.26; 95% CI 1.21, 14.9; p=0.02). Conclusion: Sequential heart–kidney transplants are associated with higher death-censored kidney allograft survival in children compared with simultaneous heart–kidney transplants. Graphical Abstract: (Figure presented.)