Safety and Efficacy of Direct Oral Anticoagulants Versus Warfarin Following WATCHMAN in High-Risk Patients.

Background: In the pivotal WATCHMAN trials, warfarin was used exclusively for postprocedural anticoagulation following left atrial appendage closure. We sought to investigate the safety and efficacy of direct oral anticoagulants (DOACs) in high-risk patients with atrial fibrillation who underwent left atrial appendage closure with WATCHMAN.

Methods: This was a retrospective study of 318 patients who underwent the WATCHMAN procedure in a tertiary referral center (June 2016-September 2020). We compared the outcomes of patients who were discharged on DOACs versus warfarin after the WATCHMAN procedure. The primary outcome was the composite of any bleeding, thromboembolism, or cardiovascular death through 7 ​days and 45 ​days after the procedure.

Results: The final analysis included 301 patients, of whom 82.4% (248/301) were discharged on DOACs and 17.6% (53/301) were discharged on warfarin. The mean CHADS-VASc and HAS-BLED scores were 4.9 ​± ​1.6 and 2.9 ​± ​0.9, respectively. The primary composite outcome was similar between the DOAC and warfarin groups through 7 ​days (3.2% vs 5.6%; adjusted odds ratio [OR], 0.65; 95% confidence interval [CI], 0.13-3.17;  ​= ​.59) and 45 days after procedure (10.1% vs 11.3%; adjusted OR, 1.18; 95% CI, 0.41-3.45;  ​= ​.76). Major bleeding (5.2% vs 9.5%;  ​= ​.34) and all-cause readmission (12.5% vs 16.9%;  ​= ​.85) at 45 ​days were comparable between the DOAC and warfarin groups. The overall incidence of device-related thrombus and significant peri-device flow at 45 ​days were low (<0.5%).

Conclusions: In high-risk patients with atrial fibrillation, the primary composite outcome of any bleeding, thromboembolism, or cardiovascular death through 7 ​days and 45 ​days following WATCHMAN implantation was similar in patients receiving DOACs versus warfarin.