Aspirin vs. Clopidogrel Monotherapy After PCI: 1-Year Follow-Up of the STOPDAPT-3 Trial
6 Oct, 2024 | 16:51h | UTCBackground: Following percutaneous coronary intervention (PCI) with drug-eluting stents (DES), patients are typically managed with dual antiplatelet therapy (DAPT). Recent evidence suggests that monotherapy with a P2Y12 inhibitor may reduce bleeding risks compared to aspirin monotherapy, but no prior trials have directly compared these regimens beyond one month of DAPT. The STOPDAPT-3 trial aimed to evaluate the cardiovascular and bleeding outcomes of aspirin versus clopidogrel monotherapy following a short duration of DAPT.
Objective: To compare the efficacy and safety of aspirin monotherapy with clopidogrel monotherapy from 1 month to 1 year after PCI with DES, focusing on cardiovascular and bleeding outcomes.
Methods: The STOPDAPT-3 trial was a prospective, multicenter, open-label, randomized clinical trial conducted in Japan. A total of 6002 patients with acute coronary syndrome (ACS) or high bleeding risk (HBR) were randomized to either a 1-month DAPT regimen followed by aspirin monotherapy (aspirin group, n=2920) or 1-month prasugrel monotherapy followed by clopidogrel monotherapy (clopidogrel group, n=2913). The primary endpoints were a composite of cardiovascular events (cardiovascular death, myocardial infarction, stent thrombosis, or ischemic stroke) and major bleeding (Bleeding Academic Research Consortium 3 or 5).
Results: At the 1-year follow-up, both the aspirin and clopidogrel groups had comparable cardiovascular outcomes (4.5% incidence in both groups; HR 1.00, 95% CI 0.77–1.30, P=0.97). Bleeding rates were also similar between groups (aspirin: 2.0%; clopidogrel: 1.9%; HR 1.02, 95% CI 0.69–1.52, P=0.92). No significant differences were observed in secondary outcomes, including all-cause mortality, myocardial infarction, stent thrombosis, or revascularization. Additionally, adherence to the assigned monotherapy at 1 year was high in both groups (87.5% for aspirin; 87.2% for clopidogrel).
Conclusions: Aspirin monotherapy, compared to clopidogrel monotherapy, resulted in similar cardiovascular and bleeding outcomes during the 1-year follow-up after PCI with DES. Both therapies appear equally effective and safe for use following short-duration DAPT.
Implications for Practice: These findings suggest that either aspirin or clopidogrel monotherapy could be safely used following a short course of DAPT, with similar clinical outcomes. In regions where more potent P2Y12 inhibitors are not widely used, aspirin monotherapy remains a cost-effective and safe alternative.
Study Strengths and Limitations: The study’s strengths include a large sample size and a well-structured, multicenter design. Limitations include the lack of randomization after 1 month and the high prescription of proton pump inhibitors, which may have affected bleeding outcomes. Additionally, the follow-up period of 1 year may be too short to detect long-term differences.
Future Research: Longer-term studies are needed to confirm the findings, particularly regarding cardiovascular outcomes beyond 1 year. Further research is also required to evaluate the impact of aspirin versus more potent P2Y12 inhibitors in diverse populations and clinical settings.