Safety and Efficacy of Routine Bridging Anticoagulation for Subtherapeutic Anticoagulation in Outpatients with a Left Ventricular Assist Device

Background Anticoagulation with vitamin K antagonists is vital to prevent pump thrombosis in patients with left ventricular assist devices (LVADs). However, the safety and efficacy of bridging anticoagulation for the routine management of subtherapeutic international normalized ratio (INR) in stable outpatients remains poorly characterized. Methods  In this retrospective study, a total of 60 LVAD outpatients had 110 episodes of subtherapeutic INR noted on routine testing. 34 of these episodes were managed with parenteral bridging anticoagulation and 76 were managed with only an adjusted dose of warfarin. The rates of bleeding and thromboembolic adverse events following these episodes of subtherapeutic INR were measured to evaluate the safety and efficacy of bridging anticoagulation in this population. Results Ischemic cerebrovascular events occurred following 2 bridged episodes compared to 4 non-bridged episodes (6% vs. 5%, p=0.895). Hemolysis occurred following 1 bridged episode compared to 3 non-bridged episodes (3% vs. 4%, p=0.794). Bleeding events occurred after 4 bridged episodes compared to 13 non-bridged episodes (12% vs. 17%, p=0.474). In a subgroup of patients with either a CHA2DS2-VASc score > 3 or a history of atrial fibrillation, thromboembolic events occurred only in those who did not receive bridging anticoagulation although this result was not statistically significant. Conclusions There was no benefit associated with the routine use of bridging anticoagulation in a general population of stable LVAD outpatients with subtherapeutic INR. A trend towards benefit was seen in a subset of patients with a CHA2DS2-VASc score of > 3 or a history of atrial fibrillation.