Percutaneous Left Atrial Appendage Closure vs Warfarin for Atrial Fibrillation

While effective in preventing stroke in patients with atrial fibrillation (AF), warfarin is limited by a narrow therapeutic profile, a need for lifelong coagulation monitoring, and multiple drug and diet interactions.

To determine whether a local strategy of mechanical left atrial appendage (LAA) closure was noninferior to warfarin. DESIGN, SETTING, AND PARTICIPANTS: PROTECT AF was a multicenter, randomized (2:1), unblinded, Bayesian-designed study conducted at 59 hospitals of 707 patients with nonvalvular AF and at least 1 additional stroke risk factor (CHADS2 score ≥1). Enrollment occurred between February 2005 and June 2008 and included 4-year follow-up through October 2012. Noninferiority required a posterior probability greater than 97.5% and superiority a probability of 95% or greater; the noninferiority margin was a rate ratio of 2.0 comparing event rates between treatment groups. INTERVENTIONS: Left atrial appendage closure with the device (n = 463) or warfarin (n = 244; target international normalized ratio, 2-3). MAIN OUTCOMES AND MEASURES: A composite efficacy end point including stroke, systemic embolism, and cardiovascular/unexplained death, analyzed by intention-to-treat.