(239) Impella Purge Solutions in Patients Receiving Extracorporeal Membrane Oxygenation

Introduction: The use of extracorporeal membrane oxygenation (ECMO) with an Impella has increased for patients experiencing post-cardiotomy and cardiogenic shock with left ventricular failure requiring mechanical offloading. Both devices may benefit from systemic anticoagulation, but the Impella device also requires a purge solution to prevent pump thrombus. Systemic anticoagulation strategies for ECMO and purge strategies for Impella have been increasingly described in patients receiving the respective single form of mechanical circulatory support but has not yet been described in patients receiving both. This study’s aim was to compare Impella device functioning in patients on ECMO receiving heparin-containing versus anticoagulant-free purge solutions.

Methods: This was a retrospective study that included adult patients receiving concomitant ECMO and Impella support for ≥ 24 hours at our institution from 2018-2023. Patients were excluded if their mechanical support configuration included a right sided Impella or right ventricular assist device. The primary outcome was the rate of Impella pump malfunction defined as two purge pressures ≥ 800 mmHg or the need for Impella device replacement without upsizing for additional support.

Results: Demographics, ECMO configuration, and Impella type were similar between patients receiving heparin-containing (n=10) or anticoagulant-free (n=15) purge. Males made up 56% of the cohort, and the average age was 56 years. A majority of patients (84%) received Impella therapy with an Impella CP. Average duration of ECMO plus Impella support was 138 hours. Only one patient in the heparin-containing purge group experienced Impella pump malfunction compared to zero in the anticoagulant-free group. Reasons for Impella removal included cardiac recovery (44%), heart transplantation (20%), death (20%), upsizing to Impella 5.5 (12%), and durable left ventricular assist device implantation (4%).

Conclusions: Patients receiving either purge solution strategy experienced a very low rate of Impella pump malfunction, including zero in the anticoagulant-free group. The use of anticoagulant-free purge solutions may simplify anticoagulation management in this complex population without sacrificing device longevity. Prospective validation is warranted.