Good to great

SEE PAGE 2329 T he PROTECT AF (Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation) trial demonstrated tremendous clinical results despite complications and procedure failures associated with the initial learning phase of the Watchman device (Boston Scientific, St. Paul, Minnesota). With 2.3 years of follow up, the primary endpoint intention to treat composite rate of all stroke, systemic embolism, and cardiovascular or unexplained death was 3.0 events per 100 patient-years with device and 4.3 events per 100 patient-years with warfarin (relative risk: 0.71). The true efficacy and potential of left atrial appendage (LAA) closure were demonstrated by the per-protocol analysis that restricted the device group to patients with successful implants who stopped taking warfarin after the specified period and patients in the control group who sustained warfarin therapy. Fewer patients in the group randomized to receive the Watchman device experienced primary efficacy events than in the control group (2.3% per year vs. 4.1% per year; probability of superiority 0.96) (1). The followup PREVAIL (Prospective Randomized Evaluation of the WATCHMAN LAA Closure Device in Patients with Atrial Fibrillation versus Long Term Warfarin Therapy) trial was recognized for its improved procedural outcomes. Clinical success defined as device deployment and release was achieved in 95% of enrolled subjects, whereas 96% were free of adverse events defined as a composite of cardiac perforation, pericardial effusion