Clopidogrel outdoes aspirin in secondary prevention after PCI

Clopidogrel is more effective than aspirin monotherapy in secondary prevention of clinical, ischaemic, and bleeding events in patients who underwent percutaneous coronary intervention (PCI), and this beneficial effect persists across high-risk subgroups, a study has shown.

A team of investigators performed a post hoc analysis of the HOST-EXAM* trial, which randomized patients who were event-free for 6 to 18 months post-PCI on dual antiplatelet therapy (DAPT) to either clopidogrel or aspirin monotherapy.

Risk stratification was done using two clinical risk scores: the DAPT score and the Thrombolysis In Myocardial Infarction Risk Score for Secondary Prevention (TRS 2°P; the sum of age ≥75 years, diabetes, hypertension, current smoking, peripheral artery disease, stroke, coronary artery bypass grafting, heart failure, and renal dysfunction).

The primary endpoint was the composite of all-cause mortality, nonfatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and major bleeding (Bleeding Academic Research Consortium type ≥3) at 2 years after randomization.

A total of 5,403 patients were included in the analysis. Clopidogrel monotherapy resulted in a lower rate of the primary endpoint compared to aspirin monotherapy (hazard ratio [HR], 0.73, 95 percent confidence interval [CI], 0.59‒0.90).

The beneficial effect of clopidogrel relative to aspirin was consistent irrespective of DAPT score (high DAPT score [≥2] group: HR, 0.68, 95 percent CI, 0.46‒1.00; low DAPT score [<2] group: HR, 0.75, 95 percent CI, 0.59‒0.96; p_interaction=0.662) and of TRS 2°P (high TRS 2°P [≥3] group: HR, 0.65, 95 percent CI, 0.44‒0.96; low TRS 2°P [<3] group: HR, 0.77, 95 percent CI, 0.60-0.99; p_interaction=0.454).

Notably, the association was also comparable for the individual outcomes.

*Harmonizing Optimal Strategy for Treatment of coronary artery diseases-EXtended Antiplatelet Monotherapy