Short-Term DAPT Followed by Clopidogrel After PCI Superior to 12-Month DAPT

One month of dual antiplatelet therapy (DAPT) followed by clopidogrel monotherapy in patients undergoing percutaneous coronary intervention (PCI) met the criteria for noninferiority and superiority when compared with 12 months of DAPT with aspirin and clopidogrel after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation, according to results of the Short and Optimal Duration of Dual AntiPlatelet Therapy-2 (STOPDAPT-2) trial published in Journal of the American Medical Association.

In this multicenter, open-label, adjudicator-blinded, randomized clinical trial, investigators screened patients who underwent successful PCI with CoCr-EES without concomitant use of other types of drug-eluting stents or in-hospital major complications (N=3045).

Patients were randomly assigned to receive either 1 month of DAPT (given between 30 and 59 days after PCI) followed by clopidogrel monotherapy (n=1523) or 12 months of DAPT with aspirin and clopidogrel (n=1522).

The primary end point was a composite of cardiovascular (CV) and bleeding events (CV death, myocardial infarction, definite stent thrombosis, ischemic or hemorrhagic stroke, thrombolysis in myocardial infarction, or major or minor bleeding). Major secondary end points included the CV end point and the bleeding end point. All end points were assessed at 12 months. All clinical events were adjudicated based on source documents by the independent clinical event committee.

The primary end point occurred in 35 patients (2.36%) in the 1-month DAPT group and in 55 patients (3.7%) in the 12-month DAPT group (hazard ratio [HR], 0.64; 95% CI, 0.42-0.98; P <.001 for noninferiority; P =.04 for superiority). The 1-month DAPT group also met noninferiority criteria to 12 months of DAPT for the major secondary CV end point (1.96% vs 2.51%; HR, 0.79; 95% CI, 0.49-1.29; P =.005 for noninferiority, P =.34 for superiority).

For the major secondary bleeding end point, the 1-month DAPT group was superior to the 12-month DAPT group (0.41% vs 1.54%; HR, 0.26; 95% CI, 0.11-0.64; P =.004).

Limitations of this study included lower-than-expected actual event rate for the primary end point, which reduced the statistical power of this noninferiority study. There was also an inability to assess the risk for stent thrombosis with very short-duration DAPT, and the majority of patients had low or intermediate ischemic risk. Because clopidogrel was chosen rather than the more commonly used aspirin as the agent for monotherapy, investigators could not assess the role of aspirin monotherapy after the very short DAPT period. The composite end point assessing both CV and bleeding events was used as the primary end point, but a consensus on the definition and validity of this for evaluating clinical benefit has yet to be reached.

Based on these findings, 1-month DAPT followed by clopidogrel monotherapy would be a potential option even for patients without major bleeding risk. Further study is needed in this population because of the high ischemic risk.

Disclosure: Abbott Vascular funded the STOPDAPT-2 study but did not provide medications or coronary devices. Several researchers acknowledged conflicts of interest. Please see reference for full list of disclosures.

Reference

Watanabe H, Domei T, Morimoto T, et al; STOPDAPT-2 Investigators. 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. JAMA. 2019;321(24):2414-2427.