Aspirin vs. clopidogrel monotherapy after percutaneous coronary intervention: 1-year follow-up of the STOPDAPT-3 trial.

Background And Aims: There was no previous trial comparing aspirin monotherapy with a P2Y12 inhibitor monotherapy following short dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stents.

Methods: In the STOPDAPT-3, patients with acute coronary syndrome or high bleeding risk (HBR) were randomly assigned to either 1-month dual antiplatelet therapy with aspirin and prasugrel followed by aspirin monotherapy (aspirin group) or 1-month prasugrel monotherapy followed by clopidogrel monotherapy (clopidogrel group). This secondary analysis compared aspirin monotherapy with clopidogrel monotherapy by the 30-day landmark analysis. The co-primary endpoints were the cardiovascular endpoint defined as a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischaemic stroke and the bleeding endpoint defined as Bleeding Academic Research Consortium 3 or 5.

Results: Of the 6002 assigned patients, 5833 patients (aspirin group: N = 2920 and clopidogrel group: N = 2913) were included in the 30-day landmark analysis. Median age was 73 (interquartile range 64-80) years, women 23.4%, acute coronary syndrome 74.6%, and high bleeding risk 54.1%. The assigned monotherapy was continued at 1 year in 87.5% and 87.2% in the aspirin and clopidogrel groups, respectively. The incidence rates beyond 30 days and up to 1 year were similar between the aspirin and clopidogrel groups for both cardiovascular endpoint [4.5 and 4.5 per 100 person-year, hazard ratio 1.00 (95% confidence interval .77-1.30), P = .97], and bleeding endpoint [2.0 and 1.9, hazard ratio 1.02 (95% confidence interval .69-1.52), P = .92].

Conclusions: Aspirin monotherapy compared with clopidogrel monotherapy was associated with similar cardiovascular and bleeding outcomes beyond 1 month and up to 1 year after percutaneous coronary intervention with drug-eluting stents (STOPDAPT-3 ClinicalTrials.gov number, NCT04609111).