Relationship between hyporesponsiveness to clopidogrel measured by thrombelastography and in stent restenosis in patients undergoing percutaneous coronary intervention

Abstract

Objectives: The relationship between hyporesponsiveness to clopidogrel and in stent restenosis (ISR) was analyzed, and the cut-off value of hyporesponsiveness to clopidogrel for ISR was evaluated.

Design and methods: 861 consecutive patients enrolled and patients' inhibition rates in arachidonic acid (AA) and adenosine 5'-diphosphate (ADP) pathways were measured by thrombelastography (TEG) system. Patients were divided into ISR and non-ISR groups according to the results of coronary angiography. Correlation between hyporesponsiveness to clopidogrel and ISR was analyzed.

Results: 249 patients were in ISR group and 612 patients were in non-ISR group. The frequency of clopidogrel hyporesponsiveness in ISR group was significantly higher than that in non-ISR group (P<0.01). Inhibition rates in AA and ADP pathways in ISR group were lower than those in non-ISR group (P<0.01). The inhibition rate in ADP pathway was inversely correlated with (r=-0.225, P=0.001) the severity of ISR. After being adjusted for traditional covariates, the inhibition rate in ADP pathway (β=-0.191, R(2)=0.011, P=0.013) remained independently associated with the severity of ISR; clopidogrel hyporesponsiveness was an independent risk factor of ISR (HR 6.62, 95% CI 2.84-15.49, P=0.001). ROC curve analysis showed that the predictive cut-off value of the inhibition rate in ADP pathway for ISR was 10.1%.

Conclusions: The inhibition rate in ADP pathway is inversely related to the ISR severity. Clopidogrel hyporesponsiveness is an independent risk factor for ISR and can predict the risk of ISR.

Keywords: Antiplatelet agents; Hyporesponsiveness to clopidogrel; In stent restenosis; Percutaneous coronary intervention; Thrombelastography.