Results:

There was a significant decline in the rate of procedure- or device-related safety events within 7 days of the procedure across the two studies, with 7.7% and 3.7% of patients, respectively, experiencing events (p = 0.007), and between the first and second halves of PROTECT AF and CAP, with 10.0%, 5.5%, and 3.7% of patients, respectively, experiencing events (p = 0.006). The rate of serious pericardial effusion within 7 days of implantation, which had made up >50% of the safety events in the PROTECT AF trial, was lower in the CAP Registry (5.0% vs. 2.2%, respectively; p = 0.019). There was a similar experience-related improvement in procedure-related stroke (0.9% vs. 0%, respectively; p = 0.039). Finally, the functional impact of these safety events, as defined by significant disability or death, was statistically superior in the Watchman group compared with the warfarin group in PROTECT AF. This remained true whether significance was defined as a change in the modified Rankin score of ≥1, ≥2, or ≥3 (1.8 vs. 4.3 events per 100 patient-years; relative risk, 0.43; 95% confidence interval, 0.24-0.82; 1.5 vs. 3.7 events per 100 patient-years; relative risk, 0.41; 95% confidence interval, 0.22-0.82; and 1.4 vs. 3.3 events per 100 patient-years; relative risk, 0.43; 95% confidence interval, 0.22-0.88, respectively).