Boston Scientific, a provider of cardiovascular implants, has completed enrolling patients in its Prevail confirmatory study.
The CE-marked self-expanding nitinol frame Watchman device, placed in the left atrial appendage (LAA) via the femoral vein and inter-atrial septum crossing into the left atrium, is designed to close the LAA, prevent clots forming within the appendage being dislodged into the bloodstream.
The prospective, randomized study, which has enrolled 407 patients at 42 sites, is designed to compare the Watchman LAA closure device to an oral anticoagulant, warfarin, in high-risk patients with atrial fibrillation eligible for long-term warfarin therapy.
The company said patients those selected to receive the Watchman device remained on warfarin for 45 days following implant.
The Watchman device proved to be non-inferior to warfarin in Protect AF trial and showed a 38% relative risk reduction for stroke, cardiovascular death and systemic embolism, compared to long-term warfarin therapy in 707 patients.
The prospective, multi-center ASAP study data also demonstrated a 77% reduction of ischemic stroke risk in AF patients implanted with the Watchman device and not eligible for blood-thinning medications.
Prevail study principal investigator and Mount Sinai Medical Center cardiac arrhythmia service director Vivek Reddy said, "WATCHMAN has the potential to provide atrial fibrillation patients with a safe and effective first-in-class device-based solution to reduce risk of stroke."