Boston Scientific completes patient enrolment in Prevail study

2 July 2012 (Last Updated July 2nd, 2012 18:30)

Boston Scientific has completed patient enrolment in its Prevail confirmatory study, designed to evaluate Watchman left atrial appendage (LAA) closure device as a treatment to reduce risk of stroke.

Boston Scientific

Boston Scientific has completed patient enrolment in its Prevail confirmatory study, designed to evaluate Watchman left atrial appendage (LAA) closure device as a treatment to reduce risk of stroke.

The CE-marked Watchman device, developed by Atritech, is a self-expanding nitinol frame comprising an access sheath and delivery system.

The device, placed in the LAA via the femoral vein and interatrial septum crossing into the left atrium, is designed to close the LAA and prevent clots forming within the appendage and being dislodged into the bloodstream.

The prospective, randomised study has enrolled 407 patients at 42 sites to compare the Watchman device to an oral anticoagulant, warfarin, in high-risk patients with atrial fibrillation (AF) eligible for long-term warfarin therapy.

Patients selected to receive the Watchman device remained on warfarin for 45 days following the implant.

The Watchman device proved to be non-inferior to warfarin in the 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, multicentre 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."

Boston Scientific cardiac rhythm management group chief medical officer, Kenneth Stein, said: "We look forward to the results of Prevail and the opportunity to enter the structural heart space in the US."


Image: Boston Scientific's corporate headquarters in Natick, Massachusetts, US. Photo courtesy of: Boston Scientific.