Patients undergoing transcatheter left atrial appendage occlusion (LAAO) with the Watchman FLX had significantly lower risk of major adverse events and ischemic stroke at one year vs. patients implanted with the Watchman 2.5 device, according to a study published May 27 in JACC: Cardiovascular Interventions.

Using data from ACC's LAAO Registry, Matthew J. Price, MD, FACC, et al., included 27,141 patients receiving the Watchman FLX and the same number of patients receiving the Watchman 2.5 device from 641 sites in the U.S. The study's primary endpoint was ischemic stroke.

At one-year follow up, results showed that patients implanted with the Watchman FLX were less likely to experience major adverse events (adjusted hazard ratio [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 authors also share findings from transesophageal echocardiography performed 45 days post procedure, where the rate of device-related thrombus was similar for patients with the Watchman FLX vs. Watchman 2.5 (0.4% vs. 0.5%; p=0.27). The rate of peridevice leak was lower in the Watchman FLX group (14.7% vs. 23.5%; p<0.001).

"The incidence of [peridevice leak] after Watchman FLX implantation was still relatively frequent, occurring in approximately one in seven patients, and therefore particular attention should be paid to technical approaches that may further enhance full anatomical closure, such as detailed preprocedural planning, meticulous intraprocedural imaging, and appropriate selection of device type and size," write the authors.

In an accompanying editorial comment, Apostolos Tzikas, MD, PhD, and Athanasios Samaras, MD, add that "the comparative one-year safety and clinical effectiveness of the Watchman FLX compared with the Watchman 2.5 device show that LAAO device design improvements play an important role in improving patient outcomes."