Clopidogrel Responsiveness in Patients Undergoing Percutaneous Coronary Intervention using Multiplate Analyzer: Frequency and Outcomes

Objectives: Over and under response to dual antiplatelet therapy (DAPT) can lead to bleeding and thrombotic events in patients undergoing coronary stent placement. The present study aimed to assess the platelet response to clopidogrel in patient undergoing percutaneous coronary intervention (PCI) using Multiplate Analyzer. The primary outcome in the present study was the short-term incidence of stent thrombosis and bleeding events. Background: Multiple electrode aggregometry is a rapid and standardized tool to for diagnosis of platelet defects and monitoring response to DAPT. Methods: A hospital-based, prospective study was conducted on 431 patients who underwent PCI from September 2016 to November 2017 and received clopidogrel therapy. The platelet aggregometry was done using a Multiplate analyzer (Dynabyte, Munich, Germany). Patients were followed for 30 days to assess the incidence of stent thrombosis and bleeding. Results: The patients’ mean age was 58 ± 6.7 years. A total of 40% of the patients were diabetic and 7.7% had chronic renal failure. The rate of clopidogrel non-responders was 10.7%, while clopidogrel over-responders were 18.3%. Patients with diabetes and chronic renal failure had significantly lower platelet responsiveness (40.1% with p < 0.05 and 7.7% with p <0.005, respectively). Smoking was significantly associated with platelet over-responsiveness (39.4%, p < 0.001). Patients with low platelet responsiveness to clopidogrel were associated with an increased risk of definite stent thrombosis (p < 0.005), while increasing bleeding risk was significantly associated with over-responsiveness to patients to clopidogrel (p <0.001). Conclusions: Antiplatelet responsiveness showing individual variability with increased risk of stent thrombosis among the cases with no response to the effect of clopidogrel and high risk of bleeding with the over-responsiveness group.