Clopidogrel Use as Single Antiplatelet Therapy in Outpatients with Stable Coronary Artery Disease: Prevalence, Correlates and Association with Prognosis (from the CORONOR Study)

Abstract

Background: Clopidogrel use as single antiplatelet therapy (SAPT) has never been evaluated in stable coronary artery disease (CAD) outpatients either as compared to placebo or aspirin. Methods: We therefore studied 2,823 outpatients included in a prospective registry. The patients were divided into 2 groups according to their antiplatelet therapy regimen: patients treated with clopidogrel were compared with those treated with aspirin alone. Results: The mean time since CAD diagnosis was 7.9 years. Altogether, 776 (27.5%) patients received clopidogrel as SAPT. Factors independently associated with clopidogrel use were prior aortic or peripheral intervention, drug-eluting stent implantation, stroke, carotid endarterectomy and time since CAD diagnosis. Clopidogrel tended to be used in higher-risk patients: composite of cardiovascular death, myocardial infarction or stroke at 5.8 versus 4.2% (p = 0.056). However, after propensity score matching, similar event rates were observed between the groups: 5.9% when treated with clopidogrel versus 4.4% with aspirin (p = 0.207). The rate of bleeding was also similar between the groups. Conclusions: Our study shows that a significant proportion of stable CAD patients are treated with clopidogrel as SAPT in modern practice. Several correlates of such an attitude were identified. Our results suggest that this strategy is not beneficial as compared to aspirin alone in terms of ischaemic or bleeding events.