Abstract 4146155: Comparative outcomes of IABP vs. Impella 5.0 and 5.5 support as a bridge to heart transplantation – a matched cohort study

Importance: Despite the increasing use of intra-aortic balloon pumps (IABP) and Impella bridge to heart transplant (HTx), there is a paucity of comparative data on their use as bridges to heart transplantation. Objective: To compare the efficacy of IABP vs Impella (5.5 and 5.0) devices as a bridge to HTx in a cohort transplanted under the current UNOS heart allocation system. Design, Setting, and Participants: A retrospective longitudinal study of the United Network for Organ Sharing (UNOS) registry included adult patients listed for HTx between Oct 2018 and April 2022 as status 2, who were supported by IABP or Impella (5.5 and 5.0) and had a complete set of demographics, hemodynamics, medical comorbidities, inotrope requirements, and biochemical variables. The primary endpoint was a successful bridging to HTx as status 2. IABP and Impella groups were propensity-matched at a 3:1 ratio for demographics, UNOS region, baseline hemodynamics, and liver and kidney function. Results: Of 32,806 HTx during the study period, 991 patients met the inclusion criteria (Impella n=88, IABP n=903). Post-matching, there were no differences between the IABP and Impella groups in any baseline characteristic. The primary outcome occurred in 89.5% of the pre-matched population (IABP 90.1% vs Impella 83%, P = 0.055). In the matched cohort, the primary outcome occurred in 85.2% (IABP 86%, Impella 83%, P = 0.603); there was no difference in the listing by exception, multiorgan transplantation, waitlist time, waitlist mortality, or delisting. Post-transplant graft survival, infection, and renal failure were not different. Impella was associated with a lower rehospitalization rate (OR 0.54, 95% CI 0.33–0.9, P = 0.02), coronary allograft vasculopathy (OR 0.23, 95% CI 0.05–1, P = 0.05), and rejection requiring hospitalization (OR 0.13, 95% CI 0.02–1, P = 0.05). Conclusions: IABP and Impella (5.5 and 5.0) devices are equally effective as bridge-to-transplant platforms with a high transplantation rate as status 2. Additionally, Impella was associated with lower post-HTx events.