Jul 8th 2014

Prospective randomized evaluation of the Watchman Left Atrial Appendage Closure device in patients with atrial fibrillation versus long-term warfarin therapy: the PREVAIL trial

Structural and Valvular

Holmes DR, Jr., Kar S, Price MJ, et al. J Am Coll Cardiol. 2014;64(1):1-12.

PREVAIL was conducted to assess a patient population with a higher stroke risk than the PROTECT AF patients as well as to assess for peri-procedure safety events (principally pericardial effusion) associated with Watchman implantation, which were observed in PROTECT AF. PREVAIL was a multicenter, 2:1-randomized controlled trial that enrolled 282 patients with non-valvular atrial fibrillation and a CHADS2 score ≥2. Subjects were randomized to treatment with the Watchman device (Boston Scientific, Marlborough, MA) or continued warfarin.

Patients treated with Watchman also received aspirin and warfarin until 45 days post-implant followed by aspirin and clopidogrel until 6 months post-implant. At 18 months, Watchman did not meet a pre-specified non-inferiority endpoint for stroke, systemic embolism, and cardiovascular death. This was attributed to a very low event rate in the warfarin group. The rate of pericardial effusion requiring intervention was much lower than in PROTECT AF.