Comparative Data of Procedural and Midterm Outcomes in Patients Who Underwent Percutaneous Left Atrial Appendage Closure Between the WATCHMAN FLX and WATCHMAN 2.5 Devices - Insight From the OCEAN-LAAC Registry.

Background: Limited data are available regarding clinical outcomes after percutaneous left atrial appendage closure using WATCHMAN FLX (WM-FLX) and WATCHMAN-2.5 (WM2.5) devices in Asian patients.

Methods and results: Data of 1,464 consecutive patients (WM-FLX, n=909; WM2.5, n=555) were extracted from a Japanese multicenter registry, and clinical data were compared between the 2 groups. No in-hospital deaths, periprocedural stroke, or device embolization occurred. Procedural success was significantly higher in the WM-FLX than WM2.5 group (95.8% vs. 91.9%; P=0.002) owing to the lower incidence of periprocedural pericardial effusion (0.55% vs. 1.8%; P=0.021). No significant differences in all-cause death, postprocedural stroke, and device-related thrombus were observed between the 2 groups. However, the cumulative bleeding rate at 1 year was substantially lower in the WM-FLX group (7.8% vs. 16.4%; P<0.001). Landmark analysis of bleeding events highlighted lower bleeding rates in the WM-FLX than WM2.5 group within the first 6 months (6.4% vs. 14.8%; P<0.001), with comparable bleeding rates over the 6- to 12-month period (1.5% vs. 3.2%, respectively; P=0.065).

Conclusions: This study demonstrated higher early safety and lower 1-year bleeding rates in the WM-FLX than WM2.5 group. The lower bleeding events with WM-FLX are likely due to multiple factors other than purely difference in devices, such as postprocedural drug regimen.