Cardiologists at Wake Forest University Baptist Medical Center are recruiting for a large-scale study on whether exercise helps people with heart failure to live longer.

About 115 patients are already participating in the international trial, but researchers say they need about 15 to 20 more people before the enrollment period ends in February.

Half of the patients enrolled in the study will exercise three times a week for three months at either Wake Forest's or Forsyth Medical Center's cardiac-rehabilitation facility. Then, those patients will exercise on treadmills or stationary bikes delivered to their homes and be expected to exercise at least three times a week.

They will get exercise tests and coaching throughout the process and be contacted for personal-health updates up to four years after enrolling.

The study, which is called HF-ACTION and is financed by the National Institutes of Health, includes 3,000 patients in the United States, France and Canada.

It seems hard to imagine now, but it used to be conventional thought among doctors that people with heart failure shouldn't exercise. But in recent years, a series of smaller trials have contradicted that, Dr. Dalane Kitzman said, though none have questioned whether or not exercise has life-extending properties. People with heart failure who exercise regularly seem to feel better and see decreased symptoms. " Now we're trying to address 'Does it help them live longer, stay out of the hospital?'" he said.

Kitzman, a cardiologist at the medical center, is the lead local researcher for the study.

"So there's been a paradigm shift," he said. "(And) slow building of information that seemed to question the conventional wisdom. This study couldn't have been done 15 years ago."

Heart-failure patients who are already exercising more than once a week aren't eligible, Kitzman said.

Heart failure is caused by damage to the heart's pumping mechanism, which in turn limits how much blood the heart can take in or the amount of force it needs to pump blood out, or both.

Symptoms include breathing difficulty, swelling in the legs, feet and ankles, and fatigue after exertion.

There is no cure for heart failure. It can be caused by coronary artery disease, high blood pressure and diabetes, and is often caused by a severe heart attack, with about 550,000 people getting the diagnosis each year, according the National Heart, Lung and Blood Institute.

"It's the only cardiovascular disease that is growing," Kitzman said. "We've saving them from death but then they end up with heart damage."

The study's results are expected next year.

Patients interested in being considered for the study may call 713-4702 for more information.

• Laura Giovanelli can be reached at 727-7302 or at lgiovanelli@wsjournal.com.