WASHINGTON, March 21 (Xinhua) -- The U.S. Food and Drug Administration (FDA) approved on Thursday a new device for treating patients with the life-threatening heart failure who are not suited for receiving alternative treatment options.

The Optimizer Smart system, comprised of an implantable pulse generator, battery charger, programer and software, can be used for chronic, moderate-to-severe heart failure, a condition in which the heart cannot pump enough blood to meet the body's needs.

"Patients with moderate-to-severe chronic heart failure have limited treatment options," said Bram Zuckerman, director of the Division of Cardiovascular Devices in the FDA's Center for Devices and Radiological Health.

They are not suited for treatment with cardiac resynchronization therapy to restore a normal timing pattern of the heartbeat, according to Zuckerman.

The new device has its pulse generator implanted under the patient's skin in the upper left or right area of the chest and connected to three leads that are implanted in the heart, according to FDA.

Then, a physician can program the device to deliver electrical impulses to the heart during regular heartbeats to help improve the heart's squeezing capability.

The FDA evaluated data from two randomized, multi-center clinical trials with a total of 389 patients with moderate-to-severe heart failure. All patients received optimal medical therapy and 191 patients also received an implant.

Patients receiving the implant showed improvements in the distance they were able to walk in six-minute walking tests and improvements on standard assessments to measure heart failure symptoms, according to FDA.