Drug-Coated Stents Safest for Whom?

Oct. 3, 2007 -- The safety of drug-coated stents is back in the news, and this time, the findings favor drug-coated stents -- at least, for some patients.

A new study shows that patients who are the most likely to need follow-up procedures after getting stents may have the best risk-benefit profile for drug-coated stents.

"This is good news, reassuring patients and cardiologists about the safety of drug-eluting stents when used in appropriate individuals," researcher Jack Tu, MD, PhD, says in a news release.

Tu works in Toronto at the Institute for Clinical Evaluative Sciences and the University of Toronto. His study appears in tomorrow's edition of The New England Journal of Medicine.

Confused about stents? Take a minute to get up to speed with the following stent facts.

Stents 101

Stents are tiny metal mesh tubes that are inserted to hold open blocked or narrowed coronary arteries.

The coronary arteries supply blood to heart muscle. If the coronary arteries narrow, a heart attack becomes more likely.

Some stents are made of bare metal. Other stents are coated with drugs that help prevent the stents from clogging up.

Recent research has raised safety concerns about drug-coated stents (also called drug-eluting stents) and the risk of blood clots, heart attacks, and death. The debate about that risk is ongoing.

Stent Study

The new stent study is based on more than 7,400 Canadians who received stents between December 2003 and March 2005.

Half of the patients received bare-metal stents. The other half received drug-coated stents.

The patients and their doctors made the decision about what type of stent to get. They weren't assigned to get a certain type of stent.

All of the patients took a blood-thinning drug for a year after getting their stents.

Tu's team followed the patients for up to three years.

Stent Survival

The patients who got drug-coated stents had a better survival rate than those who got the bare-metal stents.

During the three-year study, 5.5% of patients in the drug-coated stent group died of any cause, compared with 7.8% of those who got bare-metal stents.

The heart attack rate in the two years following stenting was similar for both groups (5.2% of patients who got bare metal stents and 5.7% of those who got drug-coated stents).

Follow-Up Surgeries

Sometimes, stented arteries become narrow again. The procedure of reopening those arteries is called revascularization.

Among the Canadian stent patients, drug-coated stents reduced revascularization, but only in patients with at least two of the following risk factors:

• Diabetes
• Skinny arteries (less than 3 millimeters in diameter)
• Long stretches of arteries that needed stenting

This study probably isn't the final word on the safety of drug-eluting stents.

Tu's team calls for larger studies in which patients are assigned to get bare-metal or drug-coated stents.

In the journal, one of Tu's colleagues -- the University of Toronto's Eric Cohen, MD -- discloses grants and speaker's fees from Boston Scientific and Cordis (a Johnson & Johnson company), which make drug-coated stents.