Chicago, IL—A triple-antiplatelet regimen that is popular in Asia was as effective as a high-dose clopidogrel dual regimen used commonly in the United States for preventing events in the first 30 days after percutaneous coronary intervention (PCI). The study was presented at the 2012 American College of Cardiology meeting by lead investigator Hyo-Soo Kim, MD, PhD, Director of Cardiac Catheterization and Coronary Intervention, Seoul National University Hospital, Republic of Korea.
The 3-drug regimen consists of cilostazol (Pletal), clopidogrel (Plavix), and aspirin. The dual regimen doubles the dose of clopidogrel in combination with aspirin.
The finding came from a large randomized trial, Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis—Safety & Effectiveness of Drug-Eluting Stents & Antiplatelet Regimen (HOST-ASSURE), which included patients undergoing PCI at 40 hospitals in the Republic of Korea.
Cilostazol is used widely in Korea and Japan to prevent embolization after PCI, because it is thought to have vascular biologic benefit in addition to its antiplatelet activity, explained Dr Kim. Cilostazol may have vasodilatory and renoprotective properties in addition to preventing stent restenosis, he said.
In HOST-ASSURE, the triple-drug approach was compared with the 2-drug regimen in 3755 patients with >50% occlusion of any coronary artery or venous or arterial bypass graft. The study was designed to demonstrate noninferiority of the triple-drug regimen.
Inhibiting platelet reactivity in the first month after PCI is critical to prevent thrombotic events, said Dr Kim. In previous trials of patients with acute coronary syndromes undergoing PCI, 1 week of double-dose clopidogrel improved outcomes at 1 month compared with conventional-dose clopidogrel.
Patients enrolled in HOST-ASSURE received 300 to 600 mg of clopidogrel plus 300 mg of aspirin before PCI, with or without a loading dose of 200 mg of cilostazol. In the group assigned to triple-antiplatelet therapy, 100 mg of cilostazol twice daily was added to dual-antiplatelet therapy for 1 month after the procedure; in the group assigned to double-dose dual-antiplatelet therapy, the maintenance regimen of clopidogrel was 150 mg daily.
The primary end point—a composite of cardiac death, nonfatal myocardial infarction (MI), stroke, definite or probable stent thrombosis, and major bleeding—occurred in 23 patients (1.22%) receiving triple-antiplatelet therapy and 27 patients (1.44%) assigned to doubledose dual-antiplatelet therapy. The absolute risk difference of –0.22% met the criterion specified for noninferiority.
The group assigned to triple-antiplatelet therapy had 1 spontaneous MI after discharge compared with 5 spontaneous MIs in the group assigned to double-dose dual-antiplatelet therapy (nonsignificant).