Drug-coated heart stents, such as the Xience model made by Abbott Labs, are as safe as the old bare metal variety for patients with narrowed large coronary arteries, a large European study showed, alleviating concerns about their long-term use.

There was no increase in the number of deaths or heart attacks two years after the drug-coated stent was implanted, according to data presented at the scientific sessions of the American Heart Association in Chicago.

The clinical trial, conducted and paid for by the University Hospital in Basel, Switzerland, is important because there had been significant concern that drug-coated stents caused blood clots to form, resulting in death or heart attack, long after implantation.

Stents are tiny wire mesh tubular devices that prop open diseased arteries. The drugs on the stent keep the vessel from reclogging, reducing the need for repeat procedures. They are implanted using a catheter that is threaded through a vessel, usually in the groin, up to the heart.

Dr. Christoph Kaiser, co-author of the study and head of interventional cardiology at the University Hospital, said drug-coated stents are generally preferred over the older bare metal stents for smaller vessels.

In addition to an improved safety profile, patients treated with drug-coated, also known as drug-eluting, stents had fewer repeat procedures.

“Now that drug-eluting stents show no late harm in large vessels, I think doctors will change,” he said.

“The fear of using drug-eluting stents in large vessels is no longer justified,” he added.

The study of 2,314 patients in Switzerland, Denmark, Austria and Italy were divided into three groups: one group got Johnson & Johnson’s Cypher-Select sirolimus-eluting stent, another got Abbott Laboratories’ Xience everolimus-eluting stent, and the other got Abbott’s Vision bare metal stent.

The patients were enrolled from March 2007 to May 2008 and after two years, the rate of cardiac death or heart attack was 2.7 percent for the sirolimus stents, 3.3 percent for the everolimus stents and 4.8 percent for the bare metal stents.

Kaiser said he was surprised by the positive results.

“We can only speculate, but it is probably due to the fact that stents are getting better over the years and so are doctors and implantation techniques,” he said.

Medtronic Inc and Boston Scientific Corp also manufacture stents.