EXCELLENT Shows Evidence for Shorter DAPT Duration After DES Implantation

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 EXCELLENT trial was presented at the ACC 60th annual scientific session in New Orleans.

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 cerebro-cardiovascular 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.

“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,” Dr. Gwon said. “However, we need to remember that this study was underpowered to test the noninferiority of the shorter duration for hard endpoints. A larger-scale randomized controlled trial is needed.”