Abstract 13842: Changes in Patient Selection and Outcomes in the New Heart Transplant Allocation Era

Abstract

Objectives The adult heart allocation policy in the United States was changed in October 2018. This study evaluates changes in patient selection and outcomes of heart transplantation over the past 3 years under this new policy. Methods: The United Network for Organ Sharing database was queried for adults undergoing isolated heart transplantation under the new allocation system between October 18, 2018 to September 25, 2021, with follow-up through September 2021. To evaluate temporal changes, the study cohort was divided at the midpoint of the study period to define early and late groups. Kaplan-Meier and multivariable Cox proportional hazards models were used for unadjusted and risk-adjusted analyses, respectively. Results: A total of 6,485 adults underwent heart transplantation in the new allocation era (2,746 early, 3,739 late). A comparison of recipient, donor, and transplant characteristics demonstrated that patients in the latter half were older, more likely blood type O, underwent durable LVAD bridging more frequently, were in the intensive care unit prior to transplant less frequently, had a higher proportion of bridging with Impella devices and lower proportion of bridging with intra-aortic balloon pumps. Donors of patients in the latter half more likely had drug overdose as the mechanism of death and more frequently had diabetes. Unadjusted and risk-adjusted 1-year survival were similar between early and late patients. Center-level analysis demonstrated that 44.6% of centers had better 1-year survival rates, 33.7% had worse, and 21.7% had similar in the latter half (Figure 1). Conclusion There have been several changes in recipient and donor characteristics in heart transplants performed in the latter half of the new allocation era although post-transplant outcomes remain similar across the study period. Figure 1 Change in center 1-year mortality rates after policy change.