Background  

DAPT (dual antiplatelet therapy) is a cornerstone in the treatment of patients after PCI and ACS. After the course of DAPT is completed, patients are typically managed long term with aspirin as a single antiplatelet.  
What question was the study supposed to answer?  

This study from the Chinese Fuwai Registry sought to compare the efficacy and safety of clopidogrel monotherapy versus aspirin monotherapy beyond 12 months after PCI in high-risk patients. 

What did the study show?  

7392 patients, who were at high risk of bleeding and thrombosis, were event free on DAPT one year post PCI. Of these, 3690 were continued on aspirin monotherapy and 1540 were continued on clopidogrel monotherapy. The outcomes of these two groups were assessed between 12- and 30-months post PCI. The primary endpoint of net adverse clinical events (death, MI, CVA, definite/probable stent thrombosis, or BARC type 2/3/5 bleeding) was significantly lower in the clopidogrel group (2.3% vs 4.4%, p=0.001). Cardiovascular events were lower in the clopidogrel group but there was no significant difference in bleeding between the two drugs. 

Why is this study important?  

The current study gives confirmatory support for the results of the prospective randomized HOST-EXAM Trial from South Korea which also found superior outcomes with clopidogrel compared to aspirin as single antiplatelet therapy following completion of DAPT (Koo et al, Lancet 2021). These studies have the potential to change clinical practice particularly if similar results can be replicated in patient populations outside of Southeast Asia.