Rates of major adverse cardiac events similar between drug-eluting stent groups

During 10 years of follow-up, the rates of major adverse cardiac events and stent thrombosis were similar among patients who received sirolimus-eluting stents and those who received paclitaxel-eluting stents, according to an analysis of a randomized trial.

After 10 years, major adverse cardiac events occurred in 32.5 percent of patients in the sirolimus-eluting stent group and 33.1 percent of patients in the paclitaxel-eluting stent group. Meanwhile, 13.3 percent of patients had definite, probable or possible stent thrombosis, and the groups had an annual rate of 1.3 percent after the first year.

Lead researcher Anders M. Galløe, MD, PhD, of Zealand University Hospital in Roskilde, Denmark, and colleagues published their results online Feb. 6 in the Journal of the American College of Cardiology.

The researchers noted that coronary drug-eluting stents were developed in 2003 to 2004. Since then, millions of patients have been treated with first-generation drug-eluting stents to relieve angina or improve their prognosis.

For this analysis, the researchers examined the SORT OUT II study, which enrolled 2,098 all-comer patients who enrolled between August 2004 and January 2006. The patients were randomized in a 1:1 ratio to receive the sirolimus-eluting stent (Cypher from Cordis and Johnson and Johnson) or the paclitaxel-eluting stent (Taxus from Boston Scientific). The only three exclusion criteria were non-Danish residency, inability to provide written informed consent and participation in other studies.

The mean age of patients was 64 years old, while 75 percent were male, 15 percent had diabetes, 17 percent had ST-segment elevation MI and 50 percent had acute coronary syndromes. Meanwhile, 67 percent of patients had one lesion, 22 percent had two lesions and 10 percent had three or more lesions.

After 10 years, major adverse cardiac events occurred in nearly one-third of patients in each group. The researchers defined major adverse cardiac events as the composite of cardiac death, MI and target vessel revascularization (TLR).

In addition, 26.9 percent of patients in sirolimus-eluting stent group and 26.3 percent of patients in the paclitaxel-eluting stent group died within 10 years. Further, TLR occurred in 15.6 percent and 14.8 percent of patients, respectively. The researchers mentioned there was no indication of a late increase in TLR rate.

There were also no statistically significant differences between the groups with regards to cardiac death, MI or stent thromboses. In all, 13.2 percent of patients had MI.

The researchers cited a few limitations of the study, including that they did not know whether patients received and took antiplatelet therapy when admitted to the hospital or were prescribed medication after they arrived at the hospital.

“There was no statistical significant difference in [major adverse cardiac events] or stent thrombosis between the 2 stent types,” the researchers wrote. “The slopes of the event curves were not increasing, and the late annual event rates seemed to be steady and the same as in the second year after stent implantation. For that reason there should be no apparent need for extraordinary medical attention to these patients. At the same time, the annual event rates did not show a diminishing trend with time. This finding is worrying and may call for continuous observation. We will continue our surveillance of the population, to ensure detection of warning signals that could call for extraordinary medical attention to the millions of people who are still living with these first-generation [drug-eluting stents].”