Physicians at 50 U.S. medical facilities are taking part in a multinational clinical trial of a device designed to help heart failure victims.

The Optimizer System is an implantable pulse generator that delivers electrical impulses to the heart for treatment of moderate-to-severe heart failure.

Physicians at the University of Texas Southwestern Medical Center say unlike other heart-failure devices, the Optimizer works by modulating the strength of the heart's contractions rather than by controlling its rhythm.

"The Optimizer could benefit up to two-thirds of advanced heart-failure patients who may not qualify for other kinds of therapy," said Dr. Jose Joglar, co-investigator of the study and associate professor of medicine in the University of Texas Southwestern's Heart, Lung and Vascular Center.

Heart failure afflicts more than 5 million people in the United States and an estimated 15 million people worldwide. It is one of the most common causes of hospitalization. In patients with heart failure, the heart muscle is too weak or damaged to pump enough blood through the body.

Copyright 2006 by United Press International