Six-Month Post-Transplant Outcomes in Patients Bridged to Heart Transplantation with IABP or Impella Following 2018 UNOS Allocation Policy Change

Abstract

Purpose We sought to compare six-month post transplantation survival among patients with Impella Devices versus intraaortic balloon pump (IABP) while on the waitlist during the year that followed the 2018 UNOS Allocation Policy change. We also compared waitlist outcomes at six months between the two groups. Methods All adult patients who were listed for heart transplantation for one year after the UNOS 2018 allocation policy change who had an IABP (n=682) or Impella device (n=65) were analyzed. Kaplan-Meier survival analysis was performed on patients who received heart transplantation. Baseline characteristics were compared using Mann-Whitney U test and Chi-square test as appropriate. Competing outcomes analysis was performed to compare heart transplantation or recovery, death or deterioration, or continuation on the waitlist at six months between the two cohorts. Results At 180 days, patients with an Impella while listed for transplantation had lower median waitlist times than patients with an IABP (median+IQR) (8.0 days[4.0, 18.0] vs. 11 days[6.0, 28.0], p = 0.013) and a greater proportion received heart transplant or achieved recovery (76.8% vs. 68.0%, p = 0.005). There was no difference in survival at 180 days post transplantation (Impella 92% [86%, 99%] vs. IABP 94% [91%,95%]), death or deterioration prior to transplant (10.7% vs. 11.0%, p = 0.943), or continuation on the waitlist (12.5% vs. 20.5%, p = 0.185). Conclusion In the year following the 2018 UNOS allocation policy change there was no difference in six month survival post heart transplantation between patients with IABP or Impella devices while waiting. Though there was a larger proportion of patients who recovered or were transplanted in the Impella cohort at six months, incidence of death or deterioration prior to transplant, or continuation on waitlist between Impella and IABP cohorts were not significantly different. Further study is warranted to understand the implications of these approaches in the context of the policy change.