Drug-eluting stents are proving beneficial in a wide range of patients and for long periods of time, according to a number of studies being presented at the American College of Cardiology's 54th Annual Scientific Session in Orlando, Florida, USA.

The REALITY trial, an international trial conducted in Europe, Latin America, and Asia, randomized a total of 1,386 patients to a sirolimus-eluting stent (CYPHER) or a paclitaxel-eluting (Taxus) coronary stent. Patients were eligible if they had up to two de novo lesions with a primary lesion of at least 15 mm in length in small vessels (2.25 to 3.0 mm in diameter).

The two study arms were well balanced in terms of standard patient characteristics including age, sex, and prior infarction. Patients were also well balanced in terms of number of diseased arteries and lesion location. On average, patients receiving the CYPHER Stent had 1.91 stents while those receiving Taxus had 1.94 stents.

Stent thrombosis is a severe complication that can result in myocardial infarction and death. Patients who receive stents are typically prescribed anti-platelet therapy to reduce the risk of thrombosis. In the REALITY trial, compliance with dual anti-platelet therapy was extremely high (99 percent for the Taxus Stent vs. 97 percent for the CYPHER Stent).

"In this study, the incidence of stent thrombosis was 78 percent lower with CYPHER Stent than with the Taxus Stent," said Principal Investigator Marie-Claude Morice, MD. "As this is the first head-to-head trial to observe a difference in the rate of stent thrombosis, these results raise concerns and demand further investigation."

The study also demonstrated that the CYPHER and Taxus Stents were equally deliverable. The study showed that both products were efficacious, at comparable rates, in preventing in-segment binary restenosis, which was the primary endpoint of the study, in moderately complex patients.

"While we see that the two drug-eluting stents were comparable in terms of the primary endpoint of restenosis, we also observed that patients who received the CYPHER Stent had a significantly larger vessel diameter inside the stent after eight months of follow-up, which is important because the vessel diameter determines the amount of blood that is delivered to the heart muscle," noted Morice.

The REALITY trial is one of several randomized controlled trials, including the ISAR-DIABETES and SIRTAX trials, comparing the two drug-eluting stents in different populations to be presented this week during the international meeting.

Several key angiographic measurements favored the CYPHER Stent at the eight-month follow-up endpoint of the REALITY study. The minimum lumen diameter was significantly larger, while the late loss (a measure of tissue in-growth into the stent) and mean percent diameter stenosis were both significantly lower with the CYPHER Stent. These important measures highlight the outstanding efficacy of this stent at preventing vessel from closing over time.