Direct Oral Anticoagulant Versus Warfarin After Left Atrial Appendage Closure With WATCHMAN: Updated Systematic Review and Meta-analysis.

In the pivotal WATCHMAN trials, warfarin was used for post-procedural anticoagulation in the first 45 days after left atrial appendage closure. We aimed to investigate the efficacy and safety of direct oral anticoagulant (DOAC) versus warfarin after WATCHMAN. We performed a literature search of 5 electronic databases to identify studies comparing DOAC with warfarin after WATCHMAN. We pooled outcomes for the efficacy (thromboembolism, device-related thrombus [DRT], peridevice leak [PDL] >5 mm) and safety endpoints (bleeding, mortality). Thromboembolism was defined as ischemic stroke, transient ischemic attack, or systemic embolism. We included 10 cohort studies with 2,440 patients, of whom 1,397 (57.3%) received DOAC. Concerning periprocedural outcomes (within 7 days following implantation), DOAC was associated with a reduction in major bleeding (Risk ratio [RR] 0.32; 95% confidence interval [CI] 0.11-0.92) compared with warfarin, without significant differences in all bleeding (RR 0.46; 95% CI 0.15-1.42) and thromboembolism (RR 0.93; 95% CI 0.21-4.16). On first follow-up transesophageal echocardiography, DRT (RR 0.79; 95% CI 0.39-1.60) and PDL>5 mm (RR 0.44; 95% CI 0.16-1.20) were comparable among groups. With a mean follow-up of 1.5-12 months, DOAC was associated with reductions in major bleeding (RR 0.52; 95% CI 0.30-0.89) and all bleeding (RR 0.38; 95% CI 0.25-0.58) compared with warfarin. The outcomes of thromboembolism (RR 0.79; 95% CI 0.36-1.73) and all-cause mortality (RR 0.49; 95% CI 0.19-1.28) were not significantly different between the 2 groups. Following WATCHMAN implantation, DOAC was associated with reductions in major bleeding and all bleeding compared with warfarin at mid-term follow-up. The outcomes of thromboembolism, all-cause mortality, DRT, and PDL >5 mm were comparable among groups.