Enoxaparin Use and Adverse Events in Outpatients With a Continuous Flow Left Ventricular Assist Device at a Single Institution

Patients with left ventricular assist devices (LVADs) are anticoagulated with warfarin and may receive enoxaparin bridging for a subtherapeutic international normalized ratio (INR). There is no guideline regarding enoxaparin bridging in LVAD patients and a dosing strategy to ensure efficacy and safety is uncertain.The objective was to characterize the use of enoxaparin bridging for subtherapeutic INRs and its impact on thrombotic or major bleeding events (MBE) in patients with an LVAD.A retrospective review from 6/1/17 to 6/30/18 was performed. Patients with an LVAD were excluded if they had less than 60 days of outpatient anticoagulation or age <18 years old. Patients were divided into 2 cohorts based on enoxaparin exposure. MBE and thrombotic events were classified as related to enoxaparin if events occurred while receiving enoxaparin and up to 7 days or 30 days, respectively, after discontinuation.Seventy-one LVAD patients met inclusion criteria and 50 patients received enoxaparin bridging. Therapeutic-dose enoxaparin was initiated at a mean INR of 1.8 for a mean duration of 2.8 days. In the enoxaparin exposure group, one MBE occurred 6 days after enoxaparin discontinuation, coinciding with an INR increase from 1.8 to 4.7. One thrombotic event occurred 2 days after enoxaparin discontinuation at an INR of 5.0.This institution's bridging strategy of therapeutic-dose enoxaparin with a short duration has a low rate of bleeding and thrombotic events. Additional prospective studies of anticoagulation bridging based on characteristics such as type of LVAD device are warranted.