The findings of the study put a question mark over the feasibility of surgical procedures to open up clogged arteries. Stents are wire-mesh tubes that stabilize a heart vessel following angioplasty, in which a tiny balloon is used to open up the clogged artery. The rationale behind stenting is that many vessels collapse soon after angioplasty, thus nullifying the benefits of the procedure.

This trial called the COURAGE (for Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation), is due to be published in the New England Journal of Medicine.. It followed 2,287 patients at 15 Veterans Administration medical centers as well as 35 other hospitals in the United States and Canada for nearly five years.

All patients in the study had at least 70 percent blockage of coronary arteries. They also suffered chest pains several times a week. Most of them had heart-risk factors like high blood pressure and high cholesterol. Some of them had diabetes as well.

The researchers assigned all patients to receive a combination of drugs like  beta-blockers, ACE inhibitors and diuretics to lower blood pressure. Additionally statins were given to decrease cholesterol, while blood thinners were given to prevent the formation of clots.

Around 50 percent of the patients received angioplasty, while many of them underwent stenting as well. There were 211 deaths in the angioplasty group in the follow up period of 4.6 years. There were attributed to heart attacks as well as strokes. However there were only 202 deaths in the group receiving only drug therapy.

The only benefit of stenting appeared to be a better flow of blood in the heart musculature, which lowered the chest pain of the patients. Three years after their surgery, 67 percent of the angioplasty group were free of chest pains, while 62 percent in the drug therapy group did not have them. The findings were details at the scientific meeting of the American College of Cardiology in New York.

"The results demonstrate that two treatments are not always better than one," said lead researcher William Boden, chief of cardiology at Buffalo (New York) General Hospital. "As so often happens, people start using these things for indications other than for what they were approved. Clinical practice got out in front of clinical evidence."

T he cardiology association says that angioplasty is performed in 1 million cases every years in the United States. Most of the patients receive stents after this procedure. The newer drug-coated stents have replaced the bare-metal stents that most patients in the above study received.

The drug-coated variety of stent was introduced three years ago and was quickly embraced by the profession in the belief that these stents were more beneficial than bare metal ones. Drug-coated stents have a major share in the $6 billion stent market in the country.

Johnson & Johnson and Boston Scientific are the market leaders although drug-eluting stents have taken a hit following reports of blood clot risks. These days doctors often prescribe anti-clotting drugs for patients who receive drug-coated stents.

The aforementioned study raises questions on the veracity of angioplasty and stenting since it is an expensive procedure costing somewhere in the region of $25,000 and $50,000. Previous studies have shown that angioplasty and stenting can save lives. However it must be pointed out that the current study followed patients with stable heart disease rather than those who suffered heart attacks.

In such patients angioplasty and stenting have unquestioned value and are thought to save lives. Critics of this study say it was conducted in Veterans Administration hospitals where patients get free drugs and are more likely to follow instructions. Another potential shortcoming of the trial may be that 85 percent of the patients were male and 86 percent of them were white.

Experts also said stents were not used to extend lives, but only improved quality of life. This statement appeared to be reinforced by the study because patients who received stents had less intensity of chest pains.

"Most people use stents for quality of life, not quantity of life," William Knopf, an interventional cardiologist at St. Joseph's Hospital in Atlanta told Reuters. "You have to put it in the context of the health-care economy. There have been a number of articles about overuse of stenting. But if it improves a patient's quality of life, is that overuse?"

So in effect stenting appears to be advisable in cases where patients experience chest pains, but the core benefits of stenting can also be availed with drug therapy as well.