DALLAS — Treatment of coronary artery in-stent restenosis with sirolimus-eluting stents cut the rate of target-vessel failure by more than 40%, compared with brachytherapy, in a study with 384 patients.
As of now, brachytherapy is the only treatment approved by the Food and Drug Administration for treating in-stent restenosis, Dr. David R. Holmes Jr. said at the annual scientific sessions of the American Heart Association. But in practice, brachytherapy has been largely abandoned, whereas drug-eluting stents have become widely used for many coronary-stenting applications.
At 9 months after treatment, the rate of the study's primary end point—target-vessel failure defined as death, myocardial infarction, or the need for target-vessel revascularization—was 12% in 259 patients who received a sirolimus-eluting stent (Cypher), compared with 22% in 125 patients treated with brachytherapy, a statistically significant difference, reported Dr. Holmes, professor of medicine at the Mayo Medical School in Rochester, Minn.
The study was sponsored by Cordis Corp., a division of Johnson & Johnson, which markets the sirolimus-eluting coronary stent. Dr. Holmes has not reported any financial relationships with Cordis or Johnson & Johnson.
The study enrolled patients during February 2003-July 2004 at 26 centers in the United States. The patients had in-stent restenosis in a native coronary artery that was 15–40 mm long and 2.5–3.5 mm in diameter. They were randomized in a 2:1 fashion, with more patients treated with sirolimus-eluting stents.
Several secondary end points were also measured. The rate of binary angiographic restenosis at 6 months after treatment was 20% in the sirolimus-eluting stent group and 30% in the brachytherapy group; the difference just missed statistical significance.
Other secondary measures that were significantly different between the two study groups included the rate of target-lesion revascularization after 9 months (9% with the sirolimus-eluting stent compared with 19% with brachytherapy), and the rate of target-vessel revascularization (11% in the stent group compared with 22% in the brachytherapy group). The average diameter stenosis in the analysis segment of the treated coronary artery 6 months after treatment was 32% in the sirolimus-eluting stent group and 41% in the brachytherapy group.
The advantages of the sirolimus-eluting stent over brachytherapy were seen regardless of whether patients had diabetes and regardless of gender. The benefit from the sirolimus-eluting stent compared with brachytherapy was greatest in medium-sized coronary arteries, compared with smaller benefits when the arteries were narrower or wider.