(949) Comparison of Bicarbonate-Based Versus Heparin-Based Impella Purge Solution

Introduction: The Impella® is a continuous axial flow pump that utilizes a purge solution to create a positive pressure barrier and prevent pump thrombosis. Both the bicarbonate-based (BBPS) and heparin-based purge solutions (HBPS) are FDA-approved, but solution choice varies in clinical practice. BBPS is approved as an alternative in patients who do not tolerate a HBPS. The BBPS ideally could serve as the standard of care to limit the complexities that come with a HBPS, however limited data are available. This study aims to compare the efficacy and safety of the BBPS versus HBPS when BBPS is used as the standard of care.

Methods: This study was a retrospective analysis at two tertiary academic medical centers within the same health-system. Adult patients were included if they required an Impella® device and received either the BBPS or HBPS for at least 72 hours between July 2022 and October 2023. The major endpoint was a composite outcome of pump thrombosis, stroke, and bleeding event defined by International Society on Thrombosis and Haemostasis criteria. Pump thrombosis was defined as incidence of two or more purge pressures greater than 800 mmHg, the use of thrombolytic purge solution, the need for an Impella® device exchange, or thrombus noted on imaging. Minor endpoints included intensive care unit (ICU) mortality, ICU length of stay, percentage of partial thromboplastin times (PTTs) within therapeutic range, incidence of supratherapeutic PTT, time to first therapeutic PTT, and vascular complications.

Results: A total of 179 patients were evaluated for inclusion of which 64 patients were included. The composite outcome occurred in 22 of 36 patients (61.1%) in the BBPS group and 17 of 28 patients (60.7%) in the HBPS group (p=0.97). There was also no difference in thrombotic, stroke or bleeding events between cohorts. Vascular events were noted in 5 (17.9%) of HBPS group and 12 (33.3%) of BBPS group (p=0.254). Additional minor endpoints were not significantly different between the groups.

Conclusions: This study found no differences in pump thrombosis, stroke, and bleeding events in the BBPS versus HBPS group. Although these findings are supportive of utilizing BBPS as standard of care, larger, multi-center studies are needed to confirm if differences in bleeding or thrombotic outcomes exist.