Clopidogrel monotherapy was associated with lower risks of major adverse cardiovascular events (MACE) and major bleeding compared with aspirin monotherapy among stable patients post PCI, according to a nationwide cohort study published June 15 in JACC: Asia.

Jun Hwan Cho, MD, et al., used the Korean nationwide claims and health examination database to compare long-term outcomes among PCI-treated patients who transitioned to either clopidogrel or aspirin monotherapy between 2009 and 2019. The co-primary outcomes were MACE, defined as a composite of cardiovascular death, myocardial infarction (MI) or ischemic stroke, and major bleeding.

The study included 133,454 patients who had received dual antiplatelet therapy (DAPT) after PCI. Of these, 67,652 patients continued on clopidogrel monotherapy and 65,802 continued on aspirin monotherapy. The median duration of DAPT was one year and duration of subsequent monotherapy was 3.3 years.

After stabilized inverse probability of treatment weighting, clopidogrel was associated with significantly lower risks of MACE (hazard ratio [HR], 0.759; p<0.0001) and major bleeding (HR, 0.895; p<0.0001) compared with aspirin.

Clopidogrel was also associated with significantly lower risks of cardiovascular death (HR, 0.605), MI (HR, 0.921) and ischemic stroke (HR, 0.674). The findings were consistent across prespecified subgroups and across different DAPT durations.

The authors noted several limitations, including potential coding errors, missing data and the possibility of unmeasured confounding due to unavailable clinical variables. Still, they concluded that "long-term clopidogrel monotherapy may be a preferable alternative to aspirin monotherapy for secondary prevention in real-world clinical practice."