Waitlist and transplant outcomes for patients bridged to heart transplantation with Impella 5.0 and 5.5 devices

Background Impella devices are increasingly utilized as a bridge to heart transplantation (BTT) and are now prioritized as Status 2 under the current heart allocation policy. This study evaluated waitlist and post-transplant outcomes of patients supported with Impella 5.0/5.5 devices. Methods The United Network of Organ Sharing registry was used to identify adults waitlisted or transplanted with Impella 5.0 or 5.5 devices from 2010 to 2021. Separate analyses were performed for waitlist and transplantation outcomes for patients supported by Impella 5.0/5.5 devices. Competing outcomes for the waitlist analysis included rates of transplantation, recovery, and death or clinical deterioration. Among patients undergoing transplantation, the primary outcome was 1-year survival. Secondary outcomes included rates of rejection, new postoperative dialysis, stroke, and pacemaker implantation after transplantation. Results There were 344 patients waitlisted and 394 patients transplanted with an Impella 5.0 (n = 212 and 251) or 5.5 (n = 132 and 143) device. Competing risk regression demonstrated similar likelihood of transplant (subhazard ratio [SHR], 1.33 (0.98-1.81, p = 0.067)) and similar likelihood of death or clinical deterioration (SHR, 0.67 [0.27-1.69, p = 0.400]) for Impella 5.5 patients. In the transplanted cohort, unadjusted 1-year post-transplant survival was comparable at 91.3% versus 94.6% (log-rank p = 0.661) for patients supported by Impella 5.0 or 5.5 device, respectively, a finding that persisted after risk-adjustment (HR 1.22, p = 0.699). Post-transplant complication rates were also comparable between 5.0 and 5.5 patients. Conclusions Impella devices can be used as a BTT with excellent survival and minimal post-transplant morbidity. Outcomes were comparable for Impella 5.0 and 5.5 devices.