177: SAFETY AND EFFECTIVENESS OF AN ANTI-XA-BASED UNFRACTIONATED HEPARIN PROTOCOL FOR IMPELLA DEVICES

Abstract

Introduction: Impella® devices are used as a short-term form of mechanical circulatory support in patients with cardiogenic shock or high-risk percutaneous coronary intervention (PCI). Anticoagulation protocols in this population are not well established. The purpose of this study was to evaluate thrombotic and bleeding complications when using an unfractionated heparin (UFH) protocol with a reduced initial dose of 6 units/kg/hour targeting an anti-Xa goal of 0.3-0.5 units/mL. Methods: This single-center, retrospective study included patients on Impella® support who received an UFH purge solution and/or an intravenous UFH infusion. The primary outcome was overall composite bleeding including major or minor bleeding or bleeding requiring medical attention. Secondary outcomes included thrombotic events and systemic UFH exposure. Results: Forty-one patients met criteria for inclusion. Anti-Xa values were in therapeutic range 46% of the time while on Impella support (interquartile range 16.6-75), with a median IV UFH dose of 6 units/kg/hour. The overall bleeding rate was 29.2% (12 total events), of which six were minor bleeds and two were major bleeds. Rates of thrombosis were low with two events during the study period. Conclusions: Use of a modified UFH protocol to target an anti-Xa goal of 0.3-0.5 units/mL prevented thromboembolic events, demonstrating the efficacy of this strategy. The majority of bleeding events were minor with no cases of fatal bleeding or intracranial hemorrhage. Based on this study, an anti-Xa goal of 0.3-0.5 units/mL with an initial rate of 6 units/kg/hr may be a useful approach to minimize heparin exposure while preventing thrombotic complications.