Postoperative Outcomes in Infants Undergoing ABO-incompatible Heart Transplantation in the United States

ABO-incompatible heart transplant is a method to increase the infant donor pool. However data on long-term survival and rejection after ABO-incompatible heart transplant in recent era are limited.

The United Network for Organ Sharing database was queried for infant heart transplants performed from January 2008 to March 2020. Patient demographics and known risk factors for posttransplant mortality were collected. Statistical analysis using Bayesian additive regression trees was performed to evaluate the association of ABO incompatibility and overall survival, graft survival, acute rejection episodes, and length of stay.

Of 1368 included infants (age < 1 year), 280 (20.47%) were ABO incompatible. ABO incompatibility was not associated with increased all-cause mortality, acute rejection episodes, or length of stay, whereas extracorporeal membrane oxygenation and intubation status of the recipient at the time of transplantation were associated with increased all-cause mortality and graft failure. Idiopathic cardiomyopathy was associated with a decreased likelihood of posttransplant all-cause mortality. One-, 5-, and 10-year survival rates among compatible vs incompatible transplants were estimated to be 90% vs 88%, 82% vs 79%, and 77% vs 73%, respectively.

ABO-incompatible infant heart transplant does not affect posttransplant survival, incidence of rejection, or postoperative length of stay. Therefore it remains a viable and important strategy to increase the infant donor pool.