WEDNESDAY, May 2 (HealthDay News) -- For elderly patients with a heart valve disease known as aortic stenosis, a procedure called a transcatheter aortic-valve implantation appears safe and effective, French researchers say.

Transcatheter aortic-valve implantation is a less invasive way of replacing the heart's aortic valve than traditional open-heart surgery. The procedure involves passing a replacement valve through a leg or shoulder artery and advancing it until it reaches the aortic valve, taking its place. The U.S. Food and Drug Administration approved the technique in 2011.

"Surgical aortic valve replacement is the definitive therapy for severe symptomatic aortic stenosis," said study co-author Dr. Martine Gilard, of the department of cardiology at Brest University Hospital in France. And transcatheter aortic-valve implantation "is a new therapeutic option for these patients," he said.

The U.S. Centers for Medicare and Medicaid Services said Monday it would cover the cost of the implantation, provided it is conducted by experienced surgeons in hospitals approved to perform the procedure. The agency estimates that 30 percent of Americans age 65 and older have aortic valve stenosis, the most common heart valve disease, or a related condition.

In aortic stenosis, the aortic valve doesn't open all the way, which reduces blood flow from the heart to the rest of the body. Severe forms can cause light-headedness and fainting.

For the study, which is scheduled to be published in the May 3 issue of the New England Journal of Medicine, the researchers evaluated data from a national registry of more than 3,100 French patients, with an average age of 82, who underwent the less invasive procedure from January 2010 to October 2011.

All the patients showed symptoms of aortic stenosis, and were considered at high risk for valve-replacement surgery.

The procedure was considered successful for almost 97 percent of the patients. Nearly 10 percent died within a month after the procedure, and 24 percent died within a year. The risk of death within a year without a valve replacement, however, is about 50 percent, the researchers noted.

The researchers also found that within one year, 4 percent of the patients suffered a stroke, and the new valve leaked in almost 65 percent of cases.

The sickest patients -- those with leaky valves and those who had the valve replaced through an artery near the collarbone -- were at greatest risk of dying, the researchers found.

About 16 percent of the patients needed a permanent pacemaker after the procedure. Although the authors acknowledged that information on complications was limited, they said the complication rate seemed acceptable given the high prevalence of coexisting illnesses.

The study was funded by Edwards Lifesciences and Medtronic, makers of the replacement valves used in the study.

Lead researcher Dr. Marc Laskar, of the department of thoracic, cardiovascular and vascular surgery at the University of Limoges and Dupuytren University Hospital in France, said the main question now is whether the procedure can be used for low-risk patients or younger patients.

To answer that question, researchers have to know the long-term results and the durability of the valve in real life, Laskar said.

"[Transcatheter aortic-valve implantation] has been demonstrated in randomized clinical trials to improve survival in patients with severe aortic stenosis who are not candidates for surgical aortic valve replacement and produce comparable outcomes to surgery in patients who are at high risk," said Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles. Fonarow was not involved in the study.

Understanding outcomes in real-world patients treated with transcatheter aortic-valve implantation is important because these patients, their physicians and hospitals can differ from those in clinical trials, Fonarow said.

This new real-world study provides valuable data on the outcome of transcatheter aortic-valve implantation.

"Prospective data such as these provide valuable insights into the implementation of novel interventional treatments into real-life clinical practice," Fonarow said.

More information

For more information on heart valve replacement, visit the American Heart Association.