(522) Impact of Blood Group on Status 2 vs Status 3 Heart Transplant Listing in the U.S

PurposeWaitlisted patients with ABO blood group O have a smaller donor pool, leading to prolonged wait times for heart transplant relative to other blood groups and thus a higher chance of waitlist death or decompensation. It is unknown whether this incentivizes Status 2 listing for blood group O patients compared with other blood groups.MethodsWe performed a retrospective analysis of all patients listed Status 2 or 3 from Oct 18th 2018 - June 30th 2022, under the current U.S allocation policy, using data from the United Network for Organ Sharing. Using logistic regression, we assessed whether type O vs A, B, and AB patients had higher odds of being listed Status 2 for shock criteria or exception compared with the odds of being listed Status 3 for shock criteria.ResultsA total 3473 patients were included, including 2521 listed Status 2 for shock criteria, 1783 listed Status 2 by exception, and 952 listed Status 3 for shock criteria. Overall, there were 1447 type O patients (42%). Type O patients with cardiac index < 2.0 L/min/m2 had similar odds of being listed Status 2 for shock criteria with temporary mechanical circulatory support (OR 1.0, P=0.76), and lower cardiac index did not modify this effect (interaction P=0.71). However, type O patients had a 20% increased odds Status 2 listing by exception compared with non-type O (OR 1.2, P=0.23, 95%CI 1.03-1.41) (Figure).ConclusionType O patients are more likely to be listed Status 2 by exception in the current US heart allocation, but they had comparable rates of Status 2 listing for shock criteria. Blood type has been incorporated into several other solid organ allocation systems in order to make organ allocation more equitable. This may be a desirable component of heart allocation in order to further reduce the reliance on exception criteria. Waitlisted patients with ABO blood group O have a smaller donor pool, leading to prolonged wait times for heart transplant relative to other blood groups and thus a higher chance of waitlist death or decompensation. It is unknown whether this incentivizes Status 2 listing for blood group O patients compared with other blood groups. We performed a retrospective analysis of all patients listed Status 2 or 3 from Oct 18th 2018 - June 30th 2022, under the current U.S allocation policy, using data from the United Network for Organ Sharing. Using logistic regression, we assessed whether type O vs A, B, and AB patients had higher odds of being listed Status 2 for shock criteria or exception compared with the odds of being listed Status 3 for shock criteria. A total 3473 patients were included, including 2521 listed Status 2 for shock criteria, 1783 listed Status 2 by exception, and 952 listed Status 3 for shock criteria. Overall, there were 1447 type O patients (42%). Type O patients with cardiac index < 2.0 L/min/m2 had similar odds of being listed Status 2 for shock criteria with temporary mechanical circulatory support (OR 1.0, P=0.76), and lower cardiac index did not modify this effect (interaction P=0.71). However, type O patients had a 20% increased odds Status 2 listing by exception compared with non-type O (OR 1.2, P=0.23, 95%CI 1.03-1.41) (Figure). Type O patients are more likely to be listed Status 2 by exception in the current US heart allocation, but they had comparable rates of Status 2 listing for shock criteria. Blood type has been incorporated into several other solid organ allocation systems in order to make organ allocation more equitable. This may be a desirable component of heart allocation in order to further reduce the reliance on exception criteria.