Multiple Electrodes Aggregometry - a New Method of Assessment of Aspirin Low Responder Status in Patients Undergoing Percutaneous Coronary Intervention (original) (raw)

Background and objectives: Recent studies showed that clopidogrel "low-responders" patients with non-ST segment elevation acute coronary syndrome (NSTE ACS) are at high risk for development of new ischemic events. The assessment of "low-or non-responder" status to dual antiplatelet therapy (aspirin and clopidogrel) in patients undergoing percutaneous coronary intervention (PCI) with coronary stent placement for NSTE ACS may be a useful method in order to detect the high-risk patients for future cardiovascular (CV) ischemic events. Methods: We prospectively studied the platelet response to both aspirin and clopidogrel in 100 NSTE ACS consecutive patients undergoing PCI with stenting for NSTE ACS admitted in Timisoara Institute of Cardiovascular Diseases CathLab during the year 2010. A single blood sample was obtained just before PCI and analyzed by platelet aggregometry using both arachidonic acids (AA) and ADP as agonists to detect the responder or non-responder status to aspirin and clopidogrel, respectively. We used the multiple electrode aggregometry (MEA) performed with Multiplate® analyzer by Dynabyte, Munich, Germany in order to assess the post-treatment platelet reactivity. Patients were stratified into quartiles according to the AA-and ADP-induced platelet aggregation. Patients of the highest quartile (quartile 4) were defined as the "low-responders". Results: Ten recurrent cardiovascular (CV) events occurred during the 1-month follow-up. Clinical cardiovascular events were significantly associated with platelet response to clopidogrel [Quartile 4 vs.1, 2, 3: OR (95% CI) 19.8 (4.4-90.8; P<0.0001)]. Conclusions: The MEA assessment of AA-and ADP-induced platelet aggregation is a valuable method to identify the low-responders to dual antiplatelet therapy. The results correlated the values of area under curve (AUC) determined by MEA with the aspirin and clopidogrel low-responder status. The clopidogrel low-responders (quartile 4) were identified as the category of patients at high risk for recurrent cardiovascular ischemic events.