Network Meta-Analysis of Initial Antithrombotic Regimens After Left Atrial Appendage Occlusion

BACKGROUND The optimal antithrombotic therapy following left atrial appendage occlusion (LAAO) in patients with nonvalvular atrial fibrillation (AF) remains uncertain. OBJECTIVES To compare the efficacy and safety of various antithrombotic strategies after LAAO. METHODS We searched MEDLINE, Cochrane, Embase, LILACS, and ClinicalTrials.gov databases for studies reporting outcomes after LAAO, stratified by antithrombotic therapy prescribed at postprocedural discharge. Direct oral anticoagulants (DOACs), vitamin-K antagonists (VKAs), single antiplatelet therapy (SAPT), dual antiplatelet therapy (DAPT), DOAC plus SAPT, VKA plus SAPT, and no antithrombotic therapy were analyzed. We performed a frequentist random-effects model network meta-analysis to estimate the odds ratio (OR) with 95% confidence intervals (CI) for each comparison. The P-scores provided a ranking of treatments. RESULTS Forty-one studies comprising 12,451 patients with nonvalvular AF were included. DAPT, DOAC, DOAC plus SAPT, and VKA were significantly superior to no therapy to prevent device-related thrombosis. DOAC was associated with lower all-cause mortality relative to VKA (OR 0.39; 95% CI 0.17-0.89; p=0.03). As compared with SAPT, DAPT was associated with less thromboembolic events (OR 0.50; 95% CI 0.29-0.88; p=0.02), without a difference in major bleeding. In the analysis of P-scores, DOAC monotherapy was the strategy most likely to have lower thromboembolic events and major bleeding. CONCLUSIONS In this network meta-analysis comparing initial antithrombotic therapies following LAAO, monotherapy with DOAC had the highest likelihood of lower thromboembolic events and major bleeding. DAPT was associated with a lower incidence of thromboembolic events compared with SAPT and may be a preferred option in patients unable to tolerate anticoagulation.