Use of Impella in Patients Listed for Heart Transplantation

Abstract

The new United Network for Organ Sharing (UNOS) policy has resulted in a significantly higher number of temporary mechanical circulatory support device usage such as extracorporeal membrane oxygenation, Impella, and intra-aortic balloon pump due to provision of higher priority with their use while on the waiting list. We aimed to identify Impella use in patients awaiting heart transplantation and temporal changes in its usage. The UNOS database was queried between years 2015 and 2019 for patients aged greater than or equal to 18 years, listed to undergo heart transplantation. A total of 378 patients had Impella support while listed for heart transplantation. Impella use skyrocketed from 2015 (1%) to 2019 (4%, p < 0.01). The most substantial increase in Impella use occurred after the UNOS policy change. The patients listed on Impella support after the policy change had significantly lower waiting time (median 12 days vs. 45 days, p < 0.01). More patients with Impella were directly transplanted (80% vs. 56%, p < 0.01) after the policy change, had significantly lower waitlist mortality (25% vs. 13%, p < 0.01) and fewer converted to a durable support (13% vs. 3%). The translatability (likelihood for receiving organs faster) was significantly improved after the policy change. A multivariable Cox regression model showed that post-transplant survival of Impella patients was not adversely affected after the policy change (hazard ratio = 0.9; p = 0.8). This increase in Impella use represents a substantial change in practice patterns of listing and managing patients on the heart transplant waiting list.