2011 ACC: Shorter Duration of Antiplatelet Therapy for Select Patients

April 6, 2011
Carole Bullock

How long should a patient take an antiplatelet drug to reduce clotting following a stent procedure?

NEW ORLEANS — April 5, 2011 – How long should a patient take an antiplatelet drug to reduce clotting following a stent procedure? This question was at the center of a new study presented today by Hyeon-Cheol Gwon, MD, PhD, Department of Cardiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.

Though current ACC/AHA guidelines answer the above question with a recommendation of 12 months or longer, Gwon says new evidence from his study, The Randomized Comparison of Six-month versus 12-month Duration of Dual Antiplatelet Therapy after Implantation of Drug Eluting Stent: From Comparison of Everolimusversus Sirolimus-Eluting Stents for Coronary Revascularization (EXCELLENT) Trial, suggest that a shorter course may be adequate for selected patients.

“The EXCELLENT study provides the first evidence that six-month antiplatelet therapy is equivalent to the 12-month prescribed by current guidelines,” he says.“Our results may be very reassuring for many physicians who need to discontinue clopidogrel before the routinely recommend 12-month duration for various reasons.”

In the 19-center trail, 1,143 patients were randomly assigned to six or 12 months of duel antiplatelet therapy with either everolimus or sirolimus.

Among the 1,428 patients for whom 12-month data was available, target vessel failure—defined as cardiac death, myocardial infarction, and target vessel revascularization—occurred in 4.7% in the six-month group and 4.4 % in the 12-month group. For this primary endpoint, the six month group was non-inferior to the 12 month group, with a pre-specificed non-inferiority margin of 40 % (p=0.0031)

The safety endpoint—a composite of death, MI, CVD accident, stent thrombosis, and thrombolysis in MI bleeding—was reached in were 24 patients (3.4%) in the six-month groups and 22 (31%) in the 12-month group. Major adverse cerebro-cardiovascular events were 54 (7.5%) and 60 (8.4%) in the six- and 12-month groups, respectively.

“At least in low-risk patients, non-diabetics and those treated with second generation DES, we may safely discontinue clopidogrel at about 6 months, especially in patients that are at high-risk of bleeding,”concludes Gwon.

The researcher emphasizes that more data is needed to confirm these findings with a larger randomized trial.