Clopidogrel monotherapy after 1-month DAPT may be beneficial in stent patients

Outcomes of the STOPDAPT-2 trial show that 1 month of dual antiplatelet therapy (DAPT) followed by clopidogrel monotherapy offers a net clinical benefit when it comes to ischaemic and bleeding events in comparison with 12 months of DAPT consisting of aspirin and clopidogrel after the implantation of cobalt-chromium everolimus-eluting stents [1].

STOPDAPT-2 was a Japanese study involving 89 centres and >3,000 patients. A total of 38% of these patients had acute coronary syndrome. Patients received DAPT for the first month (clopidogrel or prasugrel and aspirin); after that period, they were randomised to clopidogrel monotherapy or DAPT (clopidogrel and aspirin) through 1 year. The primary endpoint of the study was a composite of cardiovascular (CV) death, myocardial infarction (MI), definite stent thrombosis, stroke, or thrombolysis in myocardial infarction major/minor bleeding at 12 months.

The results suggested clopidogrel monotherapy was superior to 12 months of DAPT with regard to the primary endpoint of net adverse CV events as the rates were 2.4% and 3.7%, respectively (superiority P=0.04), and the secondary endpoint of thrombolysis in myocardial infarction major/minor bleeding (0.04% vs 1.5%; superiority P=0.004). With regard to the major secondary ischaemic endpoint (i.e. composite of cardiovascular death, MI, definite stent thrombosis, or stroke at 1 year), clopidogrel was noninferior to DAPT; the rates were 2.0% and 2.5% (non-inferiority P=0.005), respectively. There were no differences in adverse event rates at 1 year between groups. It was noted that the rates for definite and probable stent thrombosis were very low. In the subgroup analyses, similar results were seen, apart from outcomes in patients with severe chronic kidney disease, who did better when receiving 12 months of DAPT.

An important remark needs to be made on the role of intravascular imaging in this study, as this reached almost a 100% uniformity. This reflects the high standard of imaging in Japan, which may account for the observed (very) low event rates. This may not be the case in other parts of the world, and perhaps limits the generalisability of the results. Another concern is the high rate of non-responders to clopidogrel caused by the CYP2C19 carrier gene, which is often unknown when managing these patients.

1. Watanabe H, et al. Abstract 410-14. ACC 2019, 16-18 March, New Orleans, USA.



Posted on 6 June 201927 March 2024