Related Experiment Video
Updated: Sep 20, 2025

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Clinical Effectiveness of Transcatheter Left Atrial Appendage Occlusion With Watchman FLX Compared With
Matthew J Price1, Zhen Tan2, Sarah Zimmerman2
1Division of Cardiovascular Diseases, Scripps Clinic, La Jolla, California, USA.
Background:
Procedural complications, device-related thrombus, and peridevice leak may limit the benefit of transcatheter left atrial appendage occlusion (LAAO). Although next-generation devices incorporate design modifications meant to address these phenomena, the longer term impact of these modifications on outcomes has not been described.
Objectives:
The aim of this study was to compare 1-year safety and clinical effectiveness of the Watchman FLX with the predicate Watchman 2.5 device.
Methods:
The National Cardiovascular Data Registry LAAO Registry was used to identify: 1) patients who received the Watchman FLX; and 2) an identical number of patients receiving the Watchman 2.5 at the same sites directly preceding the first Watchman FLX case at each site. The primary endpoint was ischemic stroke. A secondary analysis was performed using 2:1 propensity score matching.
Results:
The study cohort consisted of 27,141 patients receiving each device. Among patients undergoing transesophageal echocardiography at 45 days, the rate of device-related thrombus was not different for Watchman FLX compared with Watchman 2.5 (0.4% vs 0.5%; P = 0.27) while the rate of any peridevice leak was significantly lower (14.7% vs 23.5%; P < 0.001). At 1 year, Watchman FLX was associated with a significantly lower risk for major adverse events (adjusted HR: 0.84; 95% CI: 0.80-0.88; P < 0.0001), ischemic stroke (adjusted HR: 0.82; 95% CI: 0.68-0.98; P = 0.02), and ischemic stroke or systemic embolism (adjusted HR: 0.74; 95% CI: 0.62-0.87; P = 0.0003). The findings of the propensity score matching analysis were similar.
Conclusions:
Transcatheter LAAO with the Watchman FLX is associated with significantly lower risks for major adverse events and ischemic stroke at 1 year compared with the predicate Watchman device. These findings suggest that enhanced procedural safety and completeness of anatomical closure translate into better longer term safety and clinical effectiveness after transcatheter LAAO.

