Clopidogrel Resistance

The objective of this clinical trial is to evaluate the efficacy and safety of platelet aggregation function - guided precision anti - platelet therapy in patients with acute cerebral infarction. The main question it aims to answer is: among the cerebral infarction patients with possible clopidogrel resistance detected by platelet aggregation function tests, what is the efficacy and safety of using ticagrelor to replace the clopidogrel treatment regimen.

The goal of this observational study is to explore the potential efficacy of related biomakers in predicting clopidogrel resistance in patients with ischemic stroke. To be specific : 1. To investigate the relationship between the changes in ADP induced platelet aggregation rate, human plasma C4BPα concentration, mRNA expression levels of mARC1 and ABCC3-013 (splicing variant) in peripheral blood leukocytes, and the changes in the mRNA expression levels of ABCC3-013 (splicing variant) in selected hospitalized patients before and on the 3rd and 7th day after antiplatelet therapy, as well as on the 30th and 90th day after follow-up, in accordance with the current guidelines for secondary stroke prevention, and to explore the relative efficacy of each biomarker in predicting clopidogrel resistance; 2. To collect blood samples from patients, extract their DNA samples, perform CYP2C19 genotyping, validate and evaluate the predictive efficacy and clinical application value of a biomarker "panel" composed of multiple new and old biomarkers for predicting clopidogrel resistance.