Outcomes after ABO-incompatible heart transplantation in adults: A registry study

In the past, ABO incompatibility was considered an absolute contraindication to heart transplantation (HT) in adults. Advances in ABO-incompatible HT in pediatric patients and ABO-incompatible abdominal transplantation in adult patients have led to clinical exploration of intentional ABO-incompatible HT in adults. However, it is not well known how outcomes in ABO-incompatible adult heart transplant recipients compare with outcomes in ABO-compatible recipients.

We analyzed International Society for Heart and Lung Transplantation transplant registry data from heart donors and recipients ≥18 years old at the time of transplant for HT performed between 1988 and 2011. We compared baseline characteristics and post-transplant outcomes in ABO-incompatible and ABO-compatible HT. Death or retransplantation was the composite primary end-point.

Among 76,663 adult patients undergoing HT between 1988 and June 30, 2011, 94 ABO-incompatible heart transplants were performed. The incidence of death or retransplantation in the ABO-incompatible group was higher than in the ABO-compatible group: 21% vs 9% at 30 days (hazard ratio = 2.38, p < 0.001) and 36% vs 19% at 1 year after transplant. However, ABO-incompatible grafts surviving past the first year after transplant had a similar incidence of failure compared with the ABO-compatible group. After 2005, the rate ABO-incompatible HT in adults increased, likely as a result of planned, intentional (rather than accidental) ABO-incompatible HT. In this group of patients, short-term and long-term incidence of death or retransplantation was similar to ABO-compatible recipients (p = 0.822): 7% at 30 days and 19% at 1 year after transplantation.

We found no difference in incidence of death or retransplantation between ABO-compatible and ABO-incompatible HT in patients who underwent transplantation after 2005.