Expanded Criteria Donor Heart Allograft Utilization: National Trends and Outcomes.

BACKGROUND: Recent trends in the utilization of expanded criteria donor organs in heart transplantation have not been studied. We assessed center-level variation in acceptance of these allografts and analyzed their post-transplant outcomes.

METHODS: Adult (≥18 years) heart transplant recipients between 2011-2022 were identified in the Organ Procurement and Transplantation Network database. Expanded criteria allografts were defined using a previously validated risk score. After stratifying centers by cumulative transplant volume, those in the top tertile (≥23/year) were considered High-Volume. Subsequently, the ratio of transplants using expanded criteria allografts to total transplants was calculated for each High-Volume center. Based on tertiles, centers were then categorized as High, Medium, and Low-Use centers. The primary outcome was death after transplantation.

RESULTS: Of 23,290 transplantations performed, 5,017(22%) utilized expanded criteria donor allografts. High-Volume heart transplant centers performed 72%(3,628) of these transplants - 1,183(75%) between 2011-2014, 1,383(73%) between 2015-October 2018, and 1,062(68%) between November 2018-June 2021. Compared to Low-Volume programs, undergoing expanded criteria heart transplantation at High-Volume centers was associated with significantly reduced hazard of mortality at one- (HR 0.78, CI 0.65-0.94, P=0.01) and five-years (HR 0.85, CI 0.75-0.98, P=0.02). During the study period, survival rates one year after transplantation were similar across High-Volume centers, regardless of their use of expanded criteria allografts.

CONCLUSIONS: Undergoing heart transplantation with an expanded criteria donor allograft at a High-Volume transplant center provides a significant survival benefit. Further, the utilization of more expanded donor criteria organs, in the right clinical settings, does not negatively impact overall patient outcomes at High-Volume centers.