Clopidogrel Resistance in Patients With Ischemic Stroke: Current Insights, Risk Factors, and the Role of Platelet Function Testing-A Narrative Review.

Clopidogrel, as an antiplatelet drug, is important for the treatment of the secondary prevention of ischemic stroke according to the latest guidelines on ischemic stroke management. However, some patients still fail to achieve a drug response and experience ischemic events despite taking clopidogrel because of differences in the production of active metabolites attributable to specific factors. Although platelet function testing plays a crucial role in evaluating the efficacy of antiplatelet drugs, research on their application remains relatively limited in the ischemic stroke population; thus, it is necessary to clarify their role in guiding individualized treatment for patients with ischemic stroke. In this review, we synthesize the current state of research on clopidogrel resistance (CR) in patients with ischemic stroke, covering key aspects such as the pharmacological mechanisms and metabolism of clopidogrel, the risk factors associated with CR, and the clinical application of platelet function testing in ischemic stroke. Our study aims to explore the prevalence and predictors of CR among patients with ischemic stroke, identify its potential impact on recurrent ischemic stroke, and thereby offer insights for the development of personalized and precision treatment strategies for clopidogrel treatment in these patients.