Comparison of oral anticoagulation and antiplatelet therapy during the midperiod after percutaneous left atrial appendage closure.

Background and aim: There is a lack of evidence comparing anticoagulation and antiplatelet therapy during the midperiod time after left atrial appendage closure (LAAC) in clinical practice (the "early period" is defined as "45 days" after LAAC for a single procedure of LAAC and "3 months" after LAAC for a combined therapy of LAAC and catheter ablation; we defined the time between the "early period" and 6 months following LAAC as the "midperiod"). Our study aims to assess the safety and effectiveness of different anticoagulant therapies in patients undergoing the LAAC procedure with the WATCHMAN device during the midperiod after LAAC implantation in clinical practice. Methods: This prospective, single-center cohort study included 374 consecutive patients undergoing percutaneous LAAC with the Watchman device. Patients were divided into two groups: oral anticoagulation (OAC) and antiplatelet therapy (APT). The primary composite endpoint was cardiac mortality, ischemic stroke/ transient ischemic attacks/systemic embolism, and major bleeding events after 6 months following the procedure. The secondary endpoints are cardiovascular death, device-related thrombosis (DRT) events, and each component of the primary endpoint. Results: The risk of the primary outcome in the APT group and the OAC group had no statistical difference in multivariable Cox regression (adjusted HR = 0.76; 95% CI: 0.40-1.49; P = 0.447). The secondary endpoints-including cardiac mortality, cardiovascular death, ischemic stroke/systemic embolism, major bleeding events, and DRT events-did not statistically differ between the two groups. Conclusion: During the midperiod time after LAAC implantation with the WATCHMAN device, OAC therapy may demonstrate similar safety and efficacy compared with dual antiplatelet therapy.