Thrombotic and bleeding events after coronary stenting according to clopidogrel and aspirin platelet reactivity: VerifyNow French Registry (VERIFRENCHY).

BACKGROUND: Dual antiplatelet therapy, comprising aspirin and clopidogrel, is recommended in patients undergoing coronary stenting to avoid the occurrence of stent thrombosis and others ischaemic events. Interindividual response to clopidogrel varies, however, with poor response associated with an increased risk of ischaemic events. New assays are available for testing aspirin and clopidogrel response routinely at the bedside.

AIM: To evaluate the prognostic value of testing antiplatelet response in an intermediate-risk population undergoing stent implantation.

METHODS: We prospectively assessed clopidogrel and aspirin response using the VerifyNow assay at the time of coronary stenting in 1001 patients who presented with stable coronary disease or non-ST-segment elevation acute coronary syndrome. The main ischaemic endpoint was the composite of definite and probable stent thrombosis, cardiovascular death or spontaneous myocardial infarction at one year. The safety endpoint was major bleeding.

RESULTS: Overall, 36.0% of patients had high on-clopidogrel platelet reactivity (OCR) and 8.6% had high on-aspirin platelet reactivity (OAR). The main ischaemic composite endpoint occurred in 3.9% of patients with high vs. 2.3% of patients with normal OCR (hazard ratio 1.66, 95% confidence interval 0.78-3.54; P=0.18). Definite or probable stent thrombosis occurred in 1.1% of patients with high vs. 0.3% of patients with normal OCR (P=0.86). There was no significant difference in ischaemic endpoints according to OAR and there was no difference in rates of major bleeding between patients with high versus normal on-treatment platelet reactivity.

CONCLUSIONS: On-treatment platelet reactivity was not associated with 1-year ischaemic or bleeding events in an intermediate-risk population undergoing stent implantation.