NEW YORK (Reuters Health) – A six-month course of triple antiplatelet therapy after drug-eluting stent implantation reduces the risk of revascularization for up to two years, according to a pooled analysis of data from two randomized trials.

The benefit is most apparent in patients at high risk of restenosis, the researchers reported in the December 7th online issue of the American Journal of Cardiology.

Dr. Seung-Whan Lee from University of Ulsan College of Medicine, Seoul, Korea and colleagues analyzed data from the DECLARE-DIABETES and DECLARE-LONG trials, which compared six months of triple therapy (with aspirin, clopidogrel and cilostazol) versus double therapy (with aspirin and clopidogrel) in patients with diabetes or long lesions. All patients in both trials received drug-eluting stents.

Overall, 450 patients were assigned to triple therapy and 450 to double therapy.

Repeat interventions were classified either as involving the stent (target lesion revascularization, or TLR) or involving a lesion in the same artery (target vessel revascularization, or TVR).

At two years, TLR rates were 4.2% with triple-therapy and 9.1% with double-therapy. TVR rates were 6.2% and 10.0% with triple and double therapy, respectively.

Also, the authors report, triple and double therapy were associated, respectively, with 5.6% and 10.4% rates of major adverse cardiac events and 7.4% and 11.4% rates of the composite outcome of death, myocardial infarction, and target vessel revascularization.

There was no difference between the groups when death, myocardial infarction, and stent thrombosis were considered individually.

In a stratified Cox analysis, the benefits of triple antiplatelet therapy were most prominent in men and in patients with paclitaxel-eluting stents, diabetes, small vessels, long lesions, or left anterior descending coronary artery lesions.

On multivariate analysis, the following factors were independently associated with the risk of target lesion revascularization at two years: cilostazol (HR 0.44), sirolimus-eluting stent (HR 0.27), postprocedural minimal lumen diameter (HR 0.43), and lesion length (HR 1.03).

The study is particularly relevant for “patients with long lesions or diabetes mellitus who usually have a high restenosis rate even in drug-eluting stent era,” Dr. Lee told Reuters Health in an email. “We think that our findings may be extrapolated to patients or lesions at high risk of restenosis after drug-eluting stent implantation, such as chronic total occlusion, ostial lesions, bifurcation stenting, and small vessel disease.”

Four years of follow-up are planned for both study cohorts, Dr. Lee added.

Reference:

Am J Cardiol 2009.