| Study Design | |
 
The WATCHMAN LAA Closure Technology is the only LAA closure device that has been studied under a multi center, prospective, randomized clinical trial. The WATCHMAN LAA Closure Technology for Embolic PROTECTion in Patients with Atrial Fibrillation (PROTECT AF) clinical trial was designed to demonstrate the safety and effectiveness of the WATCHMAN device in patients with non-valvular AF who are eligible for Warfarin therapy and have a CHADS2 stroke risk score of 1 or greater. To calculate a patient's CHADS2 score, one point is assigned each for the presence of congestive heart failure, history of hypertension, age 75 years or older, and diabetes, and two points assigned for prior stroke or TIA. The PROTECT AF clinical trials' primary efficacy endpoints were all stroke, cardiovascular death and systemic embolism. A total of 800 patients were enrolled in the study from February 2005 – June 2008 at 59 centers in the United States and Europe. All study patients were required to complete follow-up assessments at 45 days, 6 months, 9 months, 12 months and semi-annually thereafter for the duration of the study. Patients assigned to the WATCHMAN group and successfully implanted maintained Warfarin therapy for 45 days following the procedure. |