In patients maintained on dual antiplatelet therapy without clinical events after percutaneous coronary intervention (PCI) with drug-eluting stents, clopidogrel performed better than aspirin as monotherapy during long-term follow-up. The HOST-EXAM Extended study randomized 5,438 patients who had completed a course of dual antiplatelet therapy with no complications to clopidogrel 75 mg or aspirin 100 mg once daily.
Based on a composite endpoint that included all-cause mortality, several cardiac conditions, and bleeding, the study showed the following: “During median follow-up of 5.8 years (interquartile range, 4.8 and 6.2 years), the primary endpoint occurred in 12.8% and 16.9% in the clopidogrel and aspirin groups, respectively (hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.63 to 0.86, P <0.001). The clopidogrel group had a lower risk for the secondary thrombotic endpoint (7.9% vs. 11.9%; HR 0.66, 95% CI 0.55 to 0.79, P <0.001) and secondary bleeding endpoint (4.5% vs. 6.1%; HR 0.74, 95% CI 0.57 to 0.94, P = 0.016). There was no significant difference in the incidence of all-cause death between the two groups (6.2% vs. 6.0%; HR 1.04, 95% CI 0.82 to 1.31, P = 0.742). Landmark analysis at 2 years showed that the beneficial effect of clopidogrel was consistent throughout the follow-up period.”