The agreement calls for an upfront payment of $100m plus additional potential payments of up to $275m upon achievement of specified regulatory and revenue-based milestones through 2015.

Atritech’s Watchman device is designed to close the left atrial appendage, thereby preventing clots within the appendage from being dislodged into the circulation.

Atritech president and CEO Jim Bullock said both Atritech and Boston Scientific believe that the Watchman device offers the best alternative to oral anticoagulation medication for patients who suffer from atrial fibrillation and are at high risk for stroke.

"We look forward to working with Boston Scientific to expand the left atrial appendage closure market and to bring this technology to more patients worldwide," Bullock said.

Boston Scientific president and CEO Ray Elliott said this is an important acquisition in the fast-growing areas of atrial fibrillation and structural heart therapy, both of which are among their Priority Growth Initiatives.