Feb. 22, 2005 -- Drug-coated heart stents work twice as well in preventing major heart problems compared with bare-metal stents, a new study shows. Researchers say the drug-coated stents work for up to three years.
The new study "provides important insight" and a "real-world" glimpse into the effectiveness of Rapamune-treated heart stents, writes Warren K. Laskey, MD, a cardiologist with the University of New Mexico in Albuquerque, in an accompanying editorial. The new findings also "provide some reassurance about the safety" of these stents, he adds.
Stents are small, wire-mesh tubes placed in a heart artery after balloon angioplasty, a procedure to reopen the artery when it's blocked or narrowed. Heart stents act like scaffolds, widening the artery to increase the flow of blood to the heart.
There are two different kinds of available heart stents. Some are made of bare metal; others, called drug-eluting stents, have a coating that releases drugs designed to prevent repeat blockage of the artery. One of the problems seen with bare stents was growth of cells around the stents that caused the blood vessel to narrow again.
In previous studies, patients with heart stents treated with the drug Rapamune showed very few incidents of reblockage. Also, patients had very few major heart-related events like heart attack for up to one year.
In this newest study, longer-term use of Rapamune-treated heart stents was investigated. Researchers show that the drug-coated stent was superior to the bare stent in keeping arteries open for up to three years. They also show that arteries treated with the drug-coated stent developed far fewer reblockages compared with the bare-wire metal stent.
They were also associated with a lower likelihood of adverse heart problems, reports researcher Jean Fajadet, MD, with Clinique Pasteur in Toulouse, France.
His paper appears in this month's issue of Circulation, a journal of the American Heart Association.
Drug-Treated Heart Stents vs. Bare Metal
Fajadet's study involved 238 patients, 120 of whom received the Rapamune-treated heart stents instead of standard bare-metal stents. The patients were all carefully monitored for three years for evidence that arteries were narrowing again.
Researchers found significantly fewer reblockages, need for bypass surgery, or adverse heart problems, such as heart attacks, in the Rapamune-treated group, Fajadet reports.
At three years, in the drug-coated stent group, 94% didn't need a new stent. In the control group, 75% didn't require new heart stent.
Major heart-related events - such as heart attack - were also less in the Rapamune group. At year three, 16% had events, compared with 33% in the control group.