The Food and Drug Administration said Thursday it approved three implantable heart devices from Boston Scientific Corp. for a new use in treating heart failure patients.

All three devices are cardiac resynchronization therapy defibrillators. The devices are implanted in the upper chest and use electrical signals to shock the heart and correct irregular beats and then coordinate its pumping action.

The FDA approved the products for a new indication in patients with mild or asymptomatic heart failure with left bundle branch block. That condition reduces the heart's pumping ability by delaying the electrical activation of its left ventricle. This means portions of the left ventricle contract later than the rest of the heart muscle.

Previously the devices were only approved to treat patients with more severe heart failure. Boston Scientific said in a separate statement that the approval makes its devices the only ones approved by the FDA for all four classes of heart failure, as categorized by the New York Heart Association.

The FDA based its approval on an 1,800-patient study that followed patients with left bundle branch block for three years. Patients implanted with a combination resynchronization-defibrillator had a 57 percent lower rate of death and heart failure than patients who only received a defibrillator.

Natick, Mass.-based Boston Scientific markets a range of medical devices, including pacemakers, catheters and stents.

Shares of Boston Scientific rose 6 cents, or 1.1 percent, to close at $5.45.