Effect of 1-Month Dual Antiplatelet Therapy Followed by Clopidogrel vs 12-Month Dual Antiplatelet Therapy on Cardiovascular and Bleeding Events in Patients Receiving PCI The STOPDAPT-2 Randomized Clinical Trial

IMPORTANCE Very short mandatory dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with a drug-eluting stent may be an attractive option. OBJECTIVE To test the hypothesis of noninferiority of 1 month of DAPT compared with standard 12 months of DAPT for a composite end point of cardiovascular and bleeding events. DESIGN, SETTING, AND PARTICIPANTS Multicenter, open-label, randomized clinical trial enrolling 3045 patients who underwent PCI at 90 hospitals in Japan from December 2015 through December 2017. Final 1-year clinical follow-up was completed in January 2019. INTERVENTIONS Patients were randomized either to 1 month of DAPT followed by clopidogrel monotherapy (n=1523) or to 12 months of DAPT with aspirin and clopidogrel (n=1522). MAIN OUTCOMES AND MEASURES The primary end point was a composite of cardiovascular death, myocardial infarction (MI), ischemic or hemorrhagic stroke, definite stent thrombosis, or major or minor bleeding at 12 months, with a relative noninferiority margin of 50%. The major secondary cardiovascular end point was a composite of cardiovascular death, MI, ischemic or hemorrhagic stroke, or definite stent thrombosis and the major secondary bleeding end point was major or minor bleeding. RESULTS Among 3045 patients randomized, 36 withdrew consent; of 3009 remaining, 2974 (99%) completed the trial. One-month DAPT was both noninferior and superior to 12-month DAPT for the primary end point, occurring in 2.36% with 1-month DAPT and 3.70% with 12-month DAPT (absolute difference, -1.34%[95% CI, -2.57% to -0.11%]; hazard ratio [HR], 0.64 [95% CI, 0.42-0.98]), meeting criteria for noninferiority (P <.001) and for superiority (P =.04). The major secondary cardiovascular end point occurred in 1.96% with 1-month DAPT and 2.51% with 12-month DAPT (absolute difference, -0.55%[95% CI, -1.62% to 0.52%]; HR, 0.79 [95% CI, 0.49-1.29]), meeting criteria for noninferiority (P =.005) but not for superiority (P =.34). The major secondary bleeding end point occurred in 0.41% with 1-month DAPT and 1.54% with 12-month DAPT (absolute difference, -1.13%[95% CI, -1.84% to -0.42%]; HR, 0.26 [95% CI, 0.11-0.64]; P =.004 for superiority). CONCLUSIONS AND RELEVANCE Among patients undergoing PCI, 1 month of DAPT followed by clopidogrel monotherapy, compared with 12 months of DAPT with aspirin and clopidogrel, resulted in a significantly lower rate of a composite of cardiovascular and bleeding events, meeting criteria for both noninferiority and superiority. These findings suggest that a shorter duration of DAPT may provide benefit, although given study limitations, additional research is needed in other populations.