EXCELLENT

April 5, 2011—The American College of Cardiology (ACC) announced that data from the randomized controlled EXCELLENT study suggest that 6-month antiplatelet therapy is equivalent to the 12-month regimen prescribed by current guidelines for patients implanted with drug-eluting stents.

The ACC noted that the most important risk factor for late thrombosis has been stopping dual-antiplatelet therapy (DAPT) too soon, but alternatively, long durations of DAPT can increase the risk of bleeding.

“The recommended duration of DAPT was 3 to 6 months in the early introduction period of drug-eluting stents,” stated EXCELLENT investigator Hyeon-Cheol Gwon, MD. “Current American College of Cardiology/American Heart Association guidelines recommend 12 months or longer without solid scientific evidence.”

In this 19-center trial, 1,443 patients were randomly assigned to 6 or 12 months of DAPT with a stent that released either everolimus or sirolimus. Twelve-month data are available for 1,428 patients, and results of the stent trial have been presented. The ACC presentation provided findings for the first time of a comparison of 6- and 12-month DAPT with the standard combination of aspirin and clopidogrel. Patients will be followed for at least 2 more years.

According to the ACC, the EXCELLENT investigators found that target vessel failure—defined as cardiac death, myocardial infarction, and target vessel revascularization— occurred in 34 of 716 patients (4.7%) in the 6-month group and in 31 of 712 patients (4.4%) in the 12-month group. For this primary endpoint, the 6-month group was noninferior to the 12-month group, with a prespecified noninferiority margin of 40% (P = .0031).

The safety endpoint—a composite of death, myocardial infarction, cerebrovascular accident, stent thrombosis, and thrombolysis in myocardial infarction—occurred in 24 patients (3.4%) in the 6-month group and in 22 patients (3.1%) in the 12-month group. Major adverse cerebrocardiovascular events in 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.