Impact of clopidogrel treatment on platelet function and thrombogenecity in diabetic patients undergoing elective coronary stenting

High platelet reactivity (HPR) and suboptimal response to dual antiplatelet therapy (DAPT) may explain high recurrent rates of ischemic events in Type II diabetes mellitus (DM) patients undergoing percutaneous coronary intervention (PCI). The aim of this study was to examine the effect of clopidogrel on platelet reactivity, and thrombogenecity between DM and non-DM PCI-treated patients (n = 138). Patients were categorized according to clopidogrel treatment and DM status. Patients received a maintenance-dose clopidogrel of 75 mg/d (C75 group, n = 72) or a 600 mg clopidogrel loading-dose in clopidogrel na?ve patients (C600 group, n = 66). Platelet function was assessed by thrombelastography, flow cytometry, VerifyNowTM aspirin assay and light transmittance aggregometry (LTA). Aspirin response was similar between treatments and DM status. In the C75 group, DM patients had higher 5 and 20 μM ADP-, 2 μg/ml collagen-induced LTA; and p-selectin expression compared to non-DM patients (p ≤ 0.05 for all). DM patients in the C600 group had higher 5 and 20 μM ADP-induced LTA post dosing (p < 0.04) and higher maximum induced platelet-fibrin clot strength at baseline and post dosing timepoints (p < 0.05 for all). The present study provides further evidence that DM patients on DAPT are characterized by persistently higher platelet reactivity and thrombogenecity, making them potential candidates for more potent P2Y12 receptor antagonists.