Sirolimus-eluting stents may reduce the rate of major adverse cardiac events by more than half compared with paclitaxel-eluting stents in patients who have small coronary vessels, according to an article in the September 18 issue of the Journal of the American College of Cardiology.

In the SIRTAX trial, which enrolled 1,012 patients, the sirolimus-eluting stent reduced major adverse cardiac events by 55 percent (10.4 percent versus 21.4 percent) compared with paclitaxel-eluting stents. The difference seemed to be mainly due to a 69-percent reduction of target lesion revascularization (6.0 percent versus 17.7 percent) compared with the paclitaxel-eluting stent at two years. There were no significant differences between the two stents with respect to death, cardiac death or myocardial infarction at two years. In this study, reference diameter of vessels ranged from less than or equal to 2.75 mm versus more than 2.75 mm.

In large and mixed coronary vessels, the differences between the stents were less pronounced, although numerically lower with sirolimus-eluting stent. In these two patient groups, adverse event rates were similar (large, 10.4 percent versus 13.1 percent; mixed, 16.7 percent versus 18.0 percent), as were target revascularization rates (large, 6.9 percent versus 8.6 percent; mixed, 16.7 percent versus 15.4 percent) were similar.

In the subgroup analysis, the investigators studied the impact of vessel size on angiographic and long-term clinical outcomes. The study analyzed 503 patients who received the sirolimus-eluting stent and 509 patients who received paclitaxel-eluting stent.