Ce-452771-4 outcomes with different postprocedural antithrombotic therapy regimens following left atrial appendage occlusion

Percutaneous left atrial appendage occlusion (LAAO) has emerged as an alternative to oral anticoagulation (OAC) to decrease the risk of thromboembolism in patients with nonvalvular atrial fibrillation. Short-term antithrombotic therapy is required after LAAO device implantation to prevent device related thrombus until endothelialization. Prescribing patterns continue to shift nationwide and the optimal antithrombotic therapy after LAAO is not clear. To investigate the prevalence and clinical impact of different antithrombotic regimens after LAAO with WATCHMAN FLX in real-world clinical practice. Patients who underwent LAAO with WATCHMAN FLX in the National Cardiovascular Data Registry LAAO Registry between August 5, 2020 and September 30, 2021 and who had discharge medication information were included in the analysis. Endpoints were evaluated between hospital discharge and 45 day follow-up visits in patients stratified by mutually exclusive discharge medication regimens. The risk of adverse events was compared in unadjusted and adjusted patient cohorts using a Cox proportional hazards model. A total of 40,626 patients were available to analyze (n=101 had missing discharge medication data). Mean age was 76.2 years and 41.0% were female. The most common discharge medication strategies were DOAC + aspirin (48.5%) and DOAC alone (22.0%), which was markedly different from earlier studies showing warfarin and aspirin were most common. Other regimens included: dual antiplatelet therapy (DAPT; 8.1%), warfarin + aspirin (8.0%), DOAC + P2Y12 inhibitor (4.9%), single antiplatelet therapy (SAPT; 2.7%), warfarin alone (2.6%), triple therapy (1.6%), warfarin + P2Y12 inhibitor (0.7%), none (0.7%), and other (0.1%). Differences in bleeding and thromboembolic risk were found between the medication groups (Table). The adjusted risk of major adverse events (MAE) was lower in patients receiving DOAC alone (HR 0.61 [0.52, 0.72]; Figure) and higher with triple therapy (1.73 [1.24, 2.42]) compared to DOAC + aspirin treated patients in a multivariable model. In this analysis, DOAC + aspirin was the predominant discharge medication regimen after LAAO in everyday clinical practice. DOAC alone had the lowest risk of major adverse events after LAAO.