Sustained LDL-C target attainment and recurrent ischemic cerebrovascular events after ischemic stroke: effect modification by large-artery disease.

Background: In secondary prevention after ischemic stroke or TIA, LDL-C < 1.8 mmol/L is associated with a lower risk of recurrent vascular events. However, evidence remains limited in real-world patients with ischemic stroke, especially those with significant large-artery atherosclerotic stenosis. In particular, few studies have evaluated the impact of sustained LDL-C target attainment on recurrent ischemic cerebrovascular events by using LDL-C target attainment as a time-varying exposure. Methods: We retrospectively studied 933 patients with ischemic stroke who had baseline LDL-C levels ≥1.8 mmol/L at admission. Significant large-artery disease (LAD) was defined as ≥50% intracranial or extracranial atherosclerotic stenosis. LDL-C target attainment was defined as <1.8 mmol/L. The primary outcome was recurrent ischemic cerebrovascular events. Time-dependent Cox models evaluated the association between time-varying LDL-C target attainment and recurrence, and effect modification by LAD status was assessed. The proportion of follow-up time with LDL-C ≥ 1.8 mmol/L was additionally assessed. Results: Among 933 patients, 369 had LAD and 564 did not. During follow-up, 102 recurrent ischemic cerebrovascular events occurred. In the fully adjusted model, time-varying LDL-C target attainment was associated with lower recurrence risk [hazard ratio (HR) = 0.399, 95% confidence interval (CI): 0.269-0.593, Conclusion: Among patients with ischemic stroke who had baseline LDL-C levels ≥1.8 mmol/L at admission, sustained LDL-C target attainment was associated with a lower risk of recurrence after ischemic stroke. This association was particularly evident in patients with significant LAD. Sustained LDL-C control may support risk stratification and secondary prevention.