Abstract
BACKGROUND: Donor heart scarcity remains the fundamental barrier to increased transplant access. We examined whether 2018 United Network for Organ Sharing (UNOS) policy changes have had an impact on donor heart acceptance rates. METHODS AND RESULTS: We performed an interrupted time series analysis in UNOS to evaluate for abrupt changes in donor heart-acceptance rates associated with the new policy. All adult donor offers were evaluated between 2015 and 2021 (n = 66,654 donors). Donor volumes and transplants increased during this period, but the donor acceptance rate declined significantly from 31% in quarter 3 of 2018 to 26% acceptance in quarter 3 of 2021 (slope change -0.4% per quarter; P < 0.001). We identified 2 trends associated with this decline: (1) a growing number of donors with high-risk features, and (2) decreased acceptance of donors with certain high-risk features in the new allocation system. CONCLUSIONS: Heart transplant volumes have increased in recent years as a result of increased donor volumes, but donor heart acceptance rates began decreasing under the current allocation system. Changes in the donor pool and acceptance patterns for certain donor-risk features may explain this shift and warrant further evaluation to maximize donor heart use.