Shorter Antiplatelet Regimen Sufficient After Stenting

What is the optimal duration for antiplatelet therapy after placement of drug-eluting stents? Initial results of the EXCELLENT study show that 6 months of antiplatelet therapy is as effective as the 12-month regimen recommended by current American College of Cardiology (ACC)/American Heart Association guidelines. The data were presented at the ACC’s 60th Annual Scientific Session in New Orleans.

In this 19-center trial, 1443 patients were randomly assigned to 6 or 12 months of dual antiplatelet therapy (DAPT) with a stent that released either everolimus or sirolimus. This is the first presentation of findings for a comparison of 6-month and 12-month DAPT with the standard combination of aspirin and clopidogrel. Patients will be followed for at least 2 more years.

Thirty-four of 716 patients (4.7%) in the 6-month group and 31 of 712 patients (4.4%) in the 12-month group experienced target vessel failure, which was defined as cardiac death, myocardial infarction, or target vessel revascularization. For this primary endpoint, the 6-month group was non-inferior to the 12-month group, with a prespecified non-inferiority margin of 40% (P = .0031).

For the safety endpoint-a composite of death, myocardial infarction, cerebrovascular accident, stent thrombosis, and major bleeding-results were 24 (3.4%) in the 6-month group and 22 (3.1%) in the 12-month group. Major adverse cerebro-cardiovascular events for these groups were 54 (7.5%) and 60 (8.4%), respectively. The subgroup analysis by stent type showed very even numbers by outcome for the everolimus stent at 6 and 12 months, but the study was underpowered to compare the two regimens reliably for death, myocardial infarction, and stent thrombosis.

"Our results may be very reassuring for many physicians who may need to discontinue clopidogrel before the routinely recommended 12-month duration for various reasons," said study author Hyeon-Cheol Gwon, MD, PhD, of Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. "However, we need to remember that this study was underpowered to test the non-inferiority of the shorter duration for hard endpoints. A larger-scale randomized controlled trial is needed."

Gwon H-C et al. The Randomized Comparison of Six-month vs. 12-month Duration of Dual Antiplatelet Therapy After Implantation of Drug-Eluting Stent: From Comparison of Everolimus- vs. Sirolimus-Eluting Stents for Coronary Revascularization Therapy (EXCELLENT) Trial. Presented at ACC 2011. April 5, 2011. New Orleans, La.

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