Expanded Approval of Thoratec Heart Pump

The Food and Drug Administration (FDA) has approved a heart pump for patients with severe heart failure who cannot receive a transplant.

Regulators cleared Thoratec's HeartMate II, a battery-powered device that is implanted in the chest, where it helps the heart's lower left chamber pump blood throughout the body.

FDA said it approved the HeartMate II based on a company study showing 46 percent of patients implanted with the device were still alive two years later, compared with just 11 percent of patients not receiving the device. HeartMate II is a smaller version of the company's original HeartMate model.

"Its smaller size and mobility should allow more patients, including women and men of smaller stature, access to treatment," said Dr. Jeffrey Shuren, FDA's director for medical devices, in a statement.

FDA previously approved HeartMate II as a temporary treatment for patients awaiting transplant. But analysts have said the larger opportunity for the device is among patients who are not eligible for transplant because they have a limited life expectancy.

Leerink Swann analyst Rick Wise pegged the market for the new use at $2.5 billion, compared with just $250 million for patients using the device as a bridge to transplant.