Regulators have approved the sale of Edwards Life Sciences Corp's heart valve for patients deemed too sick to have open-heart surgery.

A clinical trial found that patients receiving the Sapien valve experienced two and a half times more strokes and eight times as many vascular and bleeding complications than those who did not receive the implant, but they were more likely to survive one year after surgery.

After a year, 69 percent of the Sapien patients were alive compared with 50 percent of those who received an alternative treatment.

In aortic stenosis, the aortic valve that allows blood to leave the heart does not fully open, decreasing blood flow and potentially preventing it from reaching the brain and the rest of the body.

A bad aortic valve commonly requires open-heart surgery, during which the ribs are sawed open, the heart is stopped and a new valve is sewn in place. With an Edwards' Sapien transcatheter heart valve, a catheter guides the new valve to the heart through the femoral artery in the groin or a small incision between the ribs.

Edwards has sold such a valve in Europe since 2007.

The company estimated last month that its U.S. sales of the Sapien valve would total between $150 million and $250 million in the first full year after the product is launched.

The device is expected to cost about $30,000, and will compete with a system developed by Medtronic Inc's CoreValve unit in Europe.

The Sapien valve is made of cow tissue and polyester supported with a stainless steel mesh frame.

Shares of Edwards rose 4.2 percent to $77.48 in after-hours trading following news of the approval, up from their $74.37 close.