Characteristics and Outcomes of Heart Transplants Following the Change in UNOS Allocation Policy.

The United Network for Organ Sharing instituted a new allocation policy on October 18, 2018 to better risk-stratify heart transplant recipients. We sought to evaluate changes in transplant characteristics and mid-term outcomes following this change. We conducted retrospective review of all orthotopic adult heart transplants in the UNOS registry between January 1, 2010 and March 31, 2019. Transplants were dichotomized as occurring before or after October 18, 2018. Baseline characteristics were compared, 6-month survival was assessed by the Kaplan Meier method, and a multivariate Cox proportional hazards model was used to evaluate factors associated with survival. Of 21838 heart transplants performed during the study period, 1263 (5.8%) were performed following the policy change. Distribution of recipients included 108 (9%) Status 1, 526 (42%) Status 2, 327 (26%) Status 3, 231 (19%) Status 4, 4 (0.3%) Status 5, and 45(4%) Status 6. Recipients following the policy change were more likely to be supported with a ventilator (3% vs 1%, p<0.01), IABP (23% vs 7%, p<0.01), ECMO (5% vs 1%, p<0.01) and less likely to be supported with an LVAD (36% vs 42%, p<0.01) at the time of transplant. Ischemic times were also significantly longer (3.4±1.0 vs 3.1±1.0 hrs, p<0.01). On Kaplan Meier analysis, 6-month survival was significantly worse following the change in policy (HR 1.48, 95% CI 1.16-1.88, Fig 1). On multivariate analysis, factors associated with poor survival included recipient BMI≥30 (HR1.24, 95% CI 1.11-1.39), ventilator support (HR 3.22, 95% CI 2.41-4.33), ECMO (HR 2.55, 95% CI 1.81-3.59), and increased ischemic time (HR 1.18, 95% CI 1.13-1.23). The change in UNOS allocation policy has led to decreased mid-term survival, likely as a result of increasing number of heart transplant recipients supported with a ventilator, IABP, or ECMO at the time of transplant and a decreasing number of recipients supported with an LVAD. [ABSTRACT FROM AUTHOR]