CYP2C19 genotype-guided escalation to ticagrelor vs. clopidogrel in secondary stroke prevention: a retrospective cohort study

Objective: To evaluate the effectiveness and safety of an antiplatelet therapy strategy guided by CYP2C19 genotyping in the secondary prevention of ischemic stroke in a real-world setting. Methods: This single-center retrospective cohort study enrolled 623 ischemic stroke patients. Based on their CYP2C19 genotype (extensive metabolizer [EM], intermediate metabolizer [IM], poor metabolizer [PM]) and the actual P2Y12 receptor antagonist treatment received (clopidogrel or ticagrelor), patients were categorized into natural cohorts. To minimize confounding, we applied propensity score matching, yielding a final analysis cohort of 514 patients. The primary outcome was the incidence of major adverse cardiovascular events (MACE), including stroke recurrence, myocardial infarction, and cardiovascular death, within 12 months. The secondary outcome was bleeding events. Results: > 0.05). Conclusion: Antiplatelet therapy guided by CYP2C19 genotyping is an effective strategy for optimizing the secondary prevention of ischemic stroke. For IM and PM patients, switching from clopidogrel to ticagrelor significantly reduces the risk of recurrent ischemic events without increasing bleeding risk. In contrast, for EM patients, clopidogrel remained an effective and safe option.