ADP-induced platelet aggregation and platelet reactivity index VASP are good predictive markers for clinical outcomes in non-ST elevation acute coronary syndrome

Abstract
Clopidogrel responsiveness has been proposed to be involved in recurrent ischemic events after stenting for non-ST elevation acute coronary syndromes (NSTE ACS). However, its biological definition is not consensual. We assess the value ofADP-induced platelet aggregation (ADP-Ag) and platelet reactivity indexVASP (PRI VASP) in predicting recurrent ischemic events in patients with NSTE ACS undergoing percutaneous coronary intervention (PCI). We studied 195 consecutive NSTE ACS patients undergoing PCI after a 600 mg loading dose of clopidogrel. ADPAg and PRI VASP were analysed. The primary end-point was recurrent ischemic events within 30 days of PCI. It occurred in 14 patients (7%). Construction of ROC curves to examine the value of predictive models showed that sensitivity and specificity for primary endpoint were 79% and 76%, respectively, for a maximal intensity of ADP-Ag ≥70%, 93% and 50% for PRIVASP> 53%. The positive and negative predictive values were 21% and 98%, respectively, for ADP-Ag ≥70%, 12% and 99% for PRIVASP> 53%. In patients with NSTE ACS undergoing PCI, ADP-Ag and PRI VASP identify low responders to clopidogrel with an increased risk of recurrent ischemic events with respective cut-off values of 70% and 53%.