TUESDAY, Feb. 21, 2006 (HealthDay News) -- Surgeons use them to open clogged arteries, but a major European study finds no significant difference in the performance of two models of drug-coated stents.
The results of the head-to-head comparison of the two expensive, drug-emitting mesh tubes could have major financial and medical implications.
The study, reported in the Feb. 22 issue of the Journal of the American Medical Association, was sponsored by Cordis Corp., a Johnson & Johnson unit that markets a stent coated with the drug sirolimus. That device competes with another stent coated with the drug paclitaxel, marketed by Boston Scientific.
In line with previous studies, both of the coated stents outperformed bare-metal devices in keeping arteries open. The real question has been whether one is clearly better than the other. Sirolimus has come out slightly ahead in some European studies, and it did so again in this trial --- but not overwhelmingly so.
This study, led by doctors at the Cardiovascular Institute Paris South in Massey, France, included nearly 1,400 patients who had angina (chest pain caused by reduced blood flow to the heart), and one or two new heart lesions. The patients were treated at 90 hospitals in Europe, Latin America and Asia.
The average narrowing of the artery in which a stent was placed was 9.6 percent for the sirolimus devices and 11.1 percent for the paclitaxel devices -- a difference that was not statistically significant.
The incidence of major heart problems in the 12 months after the stents were implanted was 10.7 percent in the sirolimus group and 11.4 percent in the paclitaxel group, again missing statistical significance.
A longer follow-up may be needed to see whether the differences eventually reach the threshold of statistical significance, the researchers said.
So what's a physician to do in the meantime? According to Dr. David Zimrin, director of the cardiac catheterization laboratory at the University of Maryland Medical Center, doctors may need to tailor treatment to the individual patient.
The very small differences between the two products may make one kind of stent more appropriate for one type of patient than another, he said.
For example, the paclitaxel stent is easier to implant, so it can be preferable for a patient whose arterial anatomy makes implantation difficult, Zimrin said.
On the other hand, "if there is a patient in whom you think the chances of [arterial] re-narrowing are very high, because of diabetes or already narrow arteries, you might choose the sirolimus stent," Zimrin said. "It might make a difference in that particular patient."
For patients in the middle, "the differences are small enough so that financial considerations might matter," he said.
A coated stent usually costs in the neighborhood of $2,000, Zimrin noted, and medical centers often try to drive that price down. So, all else being equal, a stent's price tag may end up being the deciding factor, he said.
One more financial issue might influence a doctor's decision, added Dr. Gene Chang, director of the catheterization laboratory at Penn Presbyterian Medical Center in Philadelphia. He noted that patients who receive a stent must also take Plavix, a clot-preventing drug, afterwards. Patients usually take the drug for two months after they receive a sirolimus-coated stent, and six months after getting a paclitaxel-coated stent.
For older people on a fixed income, that extra four months on an expensive drug can be a big factor, Chang said.
As for the medical issues, in terms of hard outcomes, there does not seem to be an difference in the published data in large-scale trials to date, Chang said. The feeling of most people that the sirolimus stent is better is based on small trials. The quagmire is that it hasn't translated into clinical benefits, he added.
For more on stents, head to the U.S. National Library of Medicine.