New device gives alternative to blood thinners in stroke pre
A new device can replace blood thinners in patients with non-valvular atrial fibrillation, which causes about 20 percent of ischemic strokes, or when blood flow to the brain is blocked - the leading cause of stroke.

The device, called the Watchman, is implanted in the left atrial appendage, where 90 percent of stroke-causing blood clots form. The device blocks the blood clots from migrating out of the appendage.