Comparison of Intra-Aortic Balloon Pump Use and Survival before and after the 2018 UNOS Allocation Policy Change

Abstract

Purpose The 2018 change in the UNOS allocation policy was implemented to decrease mortality rates for recipients on the heart transplant (HT) waiting list by prioritizing sicker patients. With this change, patients bridged with intra-aortic balloon pump (IABP) are designated as Status 2, compared to the prior allocation in which patients bridged with IABP received no status increase. We sought to examine recipient characteristics and transplant outcomes for patients bridged with IABP before and after the UNOS policy implementation. Methods We identified all adult patients (n=851) bridged to HT with IABP both 1 year before (PRE, n=169) and 1 year after (POST n=682) the UNOS allocation policy change in October, 2018 in the UNOS registry. Baseline characteristics were compared using the Mann Whitney U test and Chi square test as appropriate. Six-month survival was compared using Kaplan-Meier survival analysis. Univariate and Multivariate Cox Proportional Hazards (PH) regression analysis adjusted for policy change, recipient age, donor age, bilirubin, creatinine, dialysis use, and ischemic time. Results There was no difference in survival between the PRE and POST groups at 30 days (97% [95, 100] vs. 96% [95, 98] and 6 months 93 [90, 97] vs. 93 [91, 95] post-transplant. Baseline donor characteristics were similar between both groups, with no significant difference in pre-transplant hemodynamic indices observed. POST recipients were less likely to receive gender mismatched donor hearts (9.1% vs 23.7%, p Conclusion More patients were bridged to transplant with IABP after UNOS allocation policy changes (n=682) than before (n=169), with no significant change in survival. Baseline recipient characteristics including pre-transplant hemodynamic measurements were similar between both cohorts. The increased post-policy use of IABP in bridging to transplant may reflect providers' consideration of UNOS policy changes when selecting for mechanical circulatory support devices. Regardless, these data show that IABP is an effective strategy for bridging to transplant without increased post-transplant risk.