TUESDAY, Aug. 16, 2005 (HealthDay News) -- Two new studies make the case for the best drug to be used as a coating on metal tubes called stents, devices that keep arteries from closing again after angioplasty. The drugs are emitted from the stent over time to help fight off this dangerous reclosure.
The two contenders are paclitaxel and sirolimus -- the first produced by Boston Scientific to coat its stents, the second used on drug-eluting stents marketed by Johnson & Johnson.
And the winner, according to two European studies reported in the Aug. 18 issue of the New England Journal of Medicine, is sirolimus.
But a U.S. stent expert said the case for sirolimus is not really that clear-cut.
The first study, conducted at University Hospital Bern in Switzerland, included more than 1,000 people without major complications who had drug-eluting stents implanted after angioplasty. Only 6.6 percent of the arteries that got the sirolimus-coated stents closed again, compared to 11.7 percent of those getting the paclitaxel stents. The death rate from cardiac conditions was 0.6 percent for the sirolimus group and 1.6 percent in the paclitaxel group. And 2.8 percent of patients getting a sirolimus stent experienced a subsequent heart attack, compared to 3.5 percent of those getting a paclitaxel stent.
The second study, done at the Deutsches Herzzentrum (German Heart Center) in Munich, included 250 patients with potentially life-threatening conditions -- diabetes or coronary artery disease. Again, sirolimus-coated stents came out ahead, with only 6.9 percent of the arteries closing again, compared to 16.5 percent of those getting a paclitaxel stent.
Dr. Adnan Kastrati, professor of cardiology at the Munich center, said 90 percent of angioplasty patients there will receive sirolimus-coated stents -- not only because of these two studies, but because four other studies have also shown sirolimus to be superior.
"These six trials overall, they encompass 90 percent of the subset of patients we treat with stents," Kastrati said. "We should use sirolimus-coated stents on the basis of what the data show in these trials."
Some trials have shown a big difference between the two drugs, some have shown smaller differences, but "the higher the risk of restenosis [closing of the artery], the higher the difference in favor of sirolimus," he said.
But most angioplasty patients at the University of Kentucky will be getting paclitaxel-coated stents, countered Dr. David J. Moliterno, chief of cardiology there, who wrote an accompanying editorial in the journal.
According to Moliterno, a careful look at all 3,700 patients in the six trials shows there were negligible differences between the two stents for those at moderate risk of restenosis -- and no difference in death rates or heart attack.
Then there are practical considerations. "Paclitaxel stents are ahead in availability and deliverability," Moliterno said. "They have a shelf life of 12 months, whereas the Johnson & Johnson stent has a shelf life of three months."
And in the operating room, "the paclitaxel stent takes less time and radiation exposure to deliver," Moliterno said.
He agreed with Kastrati that the sirolimus-coated stent is best for high-risk patients. "But the majority of our patients have moderate risk factors for restenosis," Moliterno said. "Those who have more complex lesions, diabetes or a previous stent failure certainly do not account for 90 percent of our patients."
To learn more about stents, visit the U.S. Food and Drug Administration.