Increased Risk of Bleeding in Left Ventricular Assist Device Patients Treated with Enoxaparin as Bridge to Therapeutic International Normalized Ratio

Anticoagulation therapy is used to prevent thromboembolic events in patients with left ventricular assist devices (LVADs). This study aims to determine the safety of low molecular weight heparin (enoxaparin) for bridging subtherapeutic international normalized ratio (INR) in LVAD patients. In this retrospective single-center study, all patients who underwent LVAD implantation were examined between January 1, 2013, and December 31, 2014. Patients were divided into two groups: enoxaparin bridge and no bridge, with identification of major bleeding episodes (MBEs) and thrombotic events (TEs). Major bleeding episode and TE incidence was compared between the two groups, with subanalysis of incidence in the enoxaparin group between the periods on and off treatment. One hundred eighteen patients were included in this analysis. Fifty-five patients received enoxaparin, whereas 63 patients did not receive enoxaparin, with no significant difference between groups in all baseline characteristics. For the study period, enoxaparin patients had no increased incidence of MBEs (0.53 vs. 0.35 MBE per year; p = 0.12). However, there was a fourfold increase in MBEs during the bridged period in the enoxaparin group (2.02 vs. 0.45 MBE per year; p = 0.03). Major bleeding episodes on versus off enoxaparin had no major difference in transfusion requirements (2.7 ± 2.9 vs. 2.5 ± 3.4 units; p = 0.57) or mortality (p = 0.11). The enoxaparin group trended to a higher incidence of TEs (0.20 vs. 0.11 events per year; p = 0.08). Enoxaparin bridging in patients with subtherapeutic INR is associated with a significantly increased risk of MBEs. Prospective studies are needed to confirm these findings; however, until then, caution should be used with enoxaparin for bridging in LVAD patients.