BACKGROUND AND AIMS: There was no previous trial comparing aspirin monotherapy with a P2Y12 inhibitor monotherapy following short dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stents (DES).

METHODS: In the STOPDAPT-3, patients with acute coronary syndrome (ACS) or high bleeding risk (HBR) were randomly assigned to either 1-month DAPT 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 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%, ACS 74.6%, and HBR 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 [HR] 1.00 [95% confidence interval (CI) 0.77-1.30], P = .97), and bleeding endpoint (2.0 and 1.9, HR 1.02 [95% CI 0.69-1.52], P = .92).

CONCLUSIONS: Aspirin monotherapy compared to clopidogrel monotherapy was associated with similar cardiovascular and bleeding outcomes beyond 1 month and up to 1 year after PCI with DES.

Cardiology rater

As the authors point out, this technically wasn't an ASA vs clopidogrel trial since the clopidogrel group had a month of prasugrel first, during a more vulnerable period...but still useful information.

Cardiology rater

Important data demonstrating that there is no apparent clinical difference between long-term monotherapy with either aspirin or clopidogrel in patients treated with PCI in this particular study. These data can impact clinical practice and will likely be used in meta-analyses.

Hemostasis and Thrombosis rater

Aspirin monotherapy following 1-month dual antiplatelet therapy is a treatment option after PCI with DES. Confirming information.