Boston Scientific (NYSE:BSX) yesterday presented data on its Watchman left atrial appendage occlusion device. The data was presented at the annual American Heart Association’s Scientific Sessions in Orlando, Fla.

The data comes from the Ewolution registry, the 1st real-world study of the Marlborough, Mass.-based company’s Watchman device.

The patient population of the study was the ‘highest risk patient population ever studied in a Watchman trial,” Boston Scientific said. A total 61.8% of the patient population were deemed contraindicated for oral anticoagulants.

The study reported the lowest peri-procedural risk of any Watchman trial so far, even in multi-morbid patient, with a 2.8% rate of serious adverse events at 7 days. The company reported that 92.7% of patients were free from serious adverse events at 1 month post procedure.

The study will continue to follow the patients for 2-years to obtain long-term outcomes, including the rate of bleeding, stroke and transient ischemic attacks.

In June, data from a study of the Watchman returned significant results in a comparison to warfarin, an anticoagulant drug treatment, in patients with nonvalvular atrial fibrillation.

The 2,406-patient study, published in the Journal of the American College of Cardiology, reported a lower rate of hemorrhagic strokes, unexplained and cardiovascular death and non-procedural bleeding when compared to warfarin.