ABO-Incompatible Heart Transplant in Infants: A UNOS Database Review

ABO-incompatible (ABOi) heart transplantation (HT) in infants has been used to reduce waiting list time and mortality with outcomes comparable to ABO compatible (ABOc). We sought to assess trends in ABOi listing and transplantation for infants within the United Network for Organ Sharing registry and to evaluate its influence on outcomes.

We reviewed infants listed for HT in the United Network for Organ Sharing registry (2007-2018). We compared demographic and clinical characteristics, waiting list duration, graft survival, and 1-year freedom from rejection between patients listed for ABOi and ABOc. Cochran-Armitage trend test, univariate nonparametric statistical methods, and Kaplan-Meier curves were used to analyze the data.

During the study period, 2787 patients were listed for HT, 53% of whom were listed for ABOi. Median waiting list time for patients in blood group O receiving an ABOi transplant was significantly shorter (P < .0001). Among the 1862 patients who received HT, 15% were ABOi. The incidence of ABOi HT also increased over time. The pretransplant anti-A and anti-B titers in the ABOi group did not significantly affect outcomes. There was no difference in the incidence of rejection in the first year after transplant and no significant difference in posttransplant survival CONCLUSIONS: The number of infants listed and transplanted as ABOi has gradually increased over the past decade, with a significantly decreased waiting list time for ABOi transplants in blood group O. At 1 year after transplant, rejection was comparable between the ABOi and ABOc groups and there was no significant difference in survival.