Aspirin Versus Clopidogrel for Long-Term Maintenance Monotherapy After Percutaneous Coronary Intervention: The HOST-EXAM Extended Study

Long-term outcomes of antiplatelet monotherapy in patients who receive percutaneous coronary intervention are unknown. The HOST-EXAM (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis-Extended Antiplatelet Monotherapy) Extended study reports the posttrial follow-up results of the original HOST-EXAM trial. From March 2014 through May 2018, 5438 patients who maintained dual antiplatelet therapy without clinical events for 12±6 months after percutaneous coronary intervention with drug-eluting stents were randomly assigned in a 1:1 ratio to receive clopidogrel (75 mg once daily) or aspirin (100 mg once daily). The primary end point (a composite of all-cause death, nonfatal myocardial infarction, stroke, readmission attributable to acute coronary syndrome, and Bleeding Academic Research Consortium type 3 or greater bleeding), secondary thrombotic end point (cardiac death, nonfatal myocardial infarction, ischemic stroke, readmission attributable to acute coronary syndrome, and definite or probable stent thrombosis), and bleeding end point (Bleeding Academic Research Consortium type 2 or greater bleeding) were analyzed during the extended follow-up period. Analysis was performed on the per-protocol population (2431 patients in the clopidogrel group and 2286 patients in the aspirin group). During a median follow-up of 5.8 years (interquartile range, 4.8-6.2 years), the primary end point occurred in 12.8% and 16.9% in the clopidogrel and aspirin groups, respectively (hazard ratio, 0.74 [95% CI, 0.63-0.86];