Stents, made by companies such as Boston Scientific Corp, Abbott Laboratories and Medtronic Inc, are still the preferred treatment for opening up blocked heart arteries in patients rushed to the hospital with an acute heart attack.

But several studies have shown the heart devices are no better than drugs in patients with stable heart disease, in which heart arteries have narrowed and may be causing chest pain.

The latest analysis by Dr. Kathleen Stergiopoulous and Dr. David Brown of Stony Brook University Medical Center in New York, published in the Archives of Internal Medicine, attempts to knock down lingering arguments that earlier results were based on outdated technology.

Older analyses had included data from trials comparing drug treatments with balloon angioplasty, in which a balloon-tipped catheter is inserted and the balloon is inflated to open the narrowed passage.

For the latest so-called meta-analysis, the team pooled data only from newer studies that compared drug treatments with stents - a wire-mesh tube used to prop open the artery and prevent it from reclosing.

"The question was is there any benefit to stenting the blockages in these patients as an initial therapy procedure over treating them with optimal medical therapy and referring them to get a stent if necessary," Brown said in a telephone interview.

The analysis included results on more than 7,200 patients enrolled in eight studies between 1997 and 2005 comparing stents with medical therapy in stable heart patients with narrowed sections in their heart arteries.

"The result showed quite clearly there was no benefit of stenting as far as reducing death, heart attack, repeat procedures and even reducing symptomatic angina (chest pain)," Brown said.

He added that his analysis was the first to include only studies that used stents, and the results offered the most up-to-date comparison of the benefits of stenting procedures with modern medical therapy, which includes aspirin, a variety of blood pressure medicines such as beta-blockers, ACE-inhibitors or angiotensin receptor blockers and cholesterol-lowering statins.

'MISSES THE MARK'

Still, some doctors were not satisfied.

"The meta-analysis published in Archives of Internal Medicine uses old data, from 1995 to 2005, which offer little, if any, new information to guide clinical care," Dr. Theodore Bass, vice president of the Society for Cardiovascular Angiography and Interventions, a group of heart doctors that specialize in stenting procedures.

Bass said in an email that the study "misses the mark" on the quality-of-life concerns for patients and that stenting procedures helped relieve chest pain, or angina, in stable patients.

Dr. William Boden of the Samuel S. Stratton VA Medical Center in Albany, New York, who wrote a commentary in the journal, said relieving angina appeared to be the "last remaining sacred cow" for doctors who argue in favor of stents over drugs.

Boden is the lead author of a large study called COURAGE published in 2007 in the New England Journal of Medicine that was one of the first to challenge the value of stents and angioplasty over drug treatment.

In that study, patients with chest pain did get slightly more pain relief with stenting, but those benefits only lasted one to three years. "They are not durable," he said.

More recent studies could not show stents were any better than drugs at relieving angina, he contended.

Boden and Brown attribute the changes to improvements in medications, and given that most of them are generic, getting more doctors to choose drugs first could save a lot in health costs.

"In the context of controlling rising health care costs in the United States, this study suggests that up to 76 percent of patients with stable coronary artery disease could avoid percutaneous coronary intervention (such as stenting) altogether if treated with optimal medical therapy," Brown and Stergiopoulous wrote.

But fewer than half of Americans with stable coronary artery disease who get a stent have been treated with drugs first, Dr. Rita Redberg, editor of the Archives of Internal Medicine, said in an editorial.

She said more than 1 million stents were implanted each year to treat coronary artery disease in the hopes that stents would work better than drugs, despite ample evidence to the contrary.

Brown said part of the reason doctors ignored those studies was that there was a big financial incentive to use stents versus drugs.

"If I put a stent in you, I submit a bill for my fee, which could be $1,000 to $2,000. The hospital submits another bill for using the hospital, the stent, the equipment and nursing time," he said. The whole thing could add up to $20,000 or $30,000.

Brown therefore doubts the study will sway too many doctors, but said it may influence insurance companies.

"A few practitioners might change their behavior, but third-party payers will be influenced by it and they will start by making stricter criteria for reimbursing these procedures," he said.

(Reporting By Julie Steenhuysen; Editing by Peter Cooney)

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