OBJECTIVES This study sought to test the noninferiority of triple antiplatelet therapy (TAT) versus double-dose clopidogrel dual antiplatelet therapy (DDAT) in patients undergoing percutaneous coronary intervention (PCI).

BACKGROUND Antiplatelet regimen is an integral component of medical therapy after PCI. A 1-week duration of doubling the dose of clopidogrel was shown to improve outcome at 1 month compared with the conventional dose in patients with acute coronary syndrome undergoing PCI. Yet in Asia, the addition of cilostazol is used more commonly than DDAT in high-risk patients.

METHODS We randomly assigned 3,755 all-comers undergoing PCI to either TAT or DDAT, which was continued for 1 month, to test the noninferiority of TAT versus DDAT. The primary outcome was the cumulative incidence of net clinical outcome at 1 month post-PCI defined as the composite of cardiac death, nonfatal myocardial infarction, stent thrombosis, stroke, and PLATO (Platelet Inhibition and Patient Outcomes) major bleeding.

RESULTS TAT was noninferior to DDAT with respect to the primary outcome, which occurred in 1.2% and 1.4% of patients, respectively (-0.22% absolute difference, 0.34% 1-sided 97.5% confidence interval, p = 0.0007 for noninferiority; hazard ratio: 0.85; 95% confidence interval: 0.49 to 1.48; p = 0.558 for superiority). The individual risks of cardiac death, nonfatal myocardial infarction, stent thrombosis, stroke, and PLATO major bleeding did not differ significantly between the 2 groups. There were no significant between-group differences in the treatment effect with regard to the rate of the primary outcome.

CONCLUSIONS The adjunctive use of cilostazol was noninferior to doubling the dose of clopidogrel for 1 month in all-comers undergoing PCI with exclusively drug-eluting stents. (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis-SAfety & EffectiveneSS of Drug-ElUting Stents & Anti-platelet REgimen [HOST-ASSURE]; NCT01267734).