MONDAY, Dec. 22, 2003 (HealthDayNews) -- Drug-coated stents appear to be safe and effective even in a "real world" group of individuals who are more diverse and have more complicated medical problems than those who were included in the original clinical trials.
After one year, results from the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry showed that patients who received the new drug-eluting stents had slightly more than half the rate of heart attacks and other major problems than those who received the old-fashioned stents.
The results, which appear in the Dec. 23 issue of the American Heart Association journal Circulation, may help clear the way for wider use of the drug-eluting stents.
"I think there's been some limitation on use [of the drug-eluting stents], and this may open doors," says Dr. Jeffrey Moses, chief of interventional cardiology at Lenox Hill Hospital in New York City. Moses was the principal investigator on the original SIRIUS trial, which paved the way for U.S. Food and Drug Administration approval of drug-coated stents in April 2003.
"Even though they were applied to a broad range of patients, they were equally safe," Moses adds.
Bare metal stents have been used since the 1990s to prop open arteries that have been cleared by angioplasty. Unfortunately, the devices can provoke inflammation and scarring, which can cause the artery to close over again. The new Cypher stent reduces the incidence of this problem by delivering an antibiotic and an anti-inflammatory agent.
The stent has received much media attention recently because some patients experienced blood clots. Although experts indicate that the clotting rate appears to be no different than with bare metal stents, the new device is being regarded with a certain amount of caution. The current study may put some of these concerns to rest.
Clinical trials typically select participants who fit a narrow selection criteria and therefore do not necessarily correspond to the "real world," where medical and other problems are often much more complex. Indeed, according to the authors of the current study, 68 percent of the patients in the RESEARCH registry would not have made it into the clinical trials for drug-eluting stents.
This study involved 508 patients who were treated with the new Cypher stents and 450 patients who were treated with conventional bare metal stents. About half of the individuals in each group had had heart attacks or angina, and 16 percent had diabetes.
At one year after implantation, 9.7 percent of patients who received the drug-eluting stents had a heart attack or another "major adverse cardiac event," compared with 14.8 percent of those who received bare metal stents.
In the drug-eluting group, 3.7 percent had a re-narrowing of the vessel that required a repeat procedure, compared to 10.9 percent in the bare metal stent group.
The benefit of drug-eluting stents did not reach statistical significance in women or diabetics for some reason.
"If you take all of the studies, which would include this and the randomized trials that have been conducted, there is no higher incidence of complications than one would expect from stents that don't have drugs in them," says Dr. David Faxon, author of an accompanying editorial in the journal and chief of cardiology at the University of Chicago. "[Drug-eluting stents are] not riskier that what we currently do and it has better outcomes."
"All randomized trials have to be pretty selective about people. More complicated kinds of patients or anatomical situations are excluded," Faxon continues. "This [new study] didn't do that. They just did everybody who came into their laboratory, in which case you really get a good picture of how this device performs [in situations and people]. That hadn't been done before, and it seems to perform very well. That's very reassuring."
Faxon's editorial says the FDA should establish a mandatory registry to follow problems associated with the stents. The agency has said it has ordered the stent's maker to report these problems.