ABSTRACT NUMBER: ESOC2026A2124 LIPOPROTEIN(A) AND RISK OF SYMPTOMATIC INTRACRANIAL ATHEROSCLEROTIC STENOSIS IN PATIENTS WITH ACUTE ISCHEMIC STROKE

Abstract Background and aims The contribution of Lipoprotein(a) [Lp(a)] to symptomatic intracranial atherosclerotic stenosis (sICAS) has not been adequately investigated in Caucasians. We aimed to examine the association between Lp(a) levels and sICAS among patients with acute ischemic stroke (AIS), along with its association with large-artery atherosclerosis (LAA). Methods Consecutive AIS patients were prospectively enrolled. sICAS was defined as 50–99% stenosis of an intracranial artery corresponding to the index infarct. Multivariable logistic regression models were used to assess the association between Lp(a) and sICAS after adjustment for demographic and vascular risk factors. Discriminatory performance was evaluated using receiver operating characteristic (ROC) analysis. Secondary analyses examined associations between Lp(a) and LAA-stroke. Results Among 407 patients, 43 (10.6%) had sICAS. Higher Lp(a) levels were independently associated with sICAS after multivariable adjustment. A one-unit increase in log₁₀-transformed Lp(a) was associated with 3-fold higher odds of sICAS (aOR, 3.34; 95% CI, 1.78–6.25), while each 10 nmol/L increase conferred a 5% rise in risk. Patients with Lp(a) concentrations ≥75 nmol/L had approximately 3-fold higher odds of sICAS. ROC analysis identified an Lp(a) cutoff of 53.8 nmol/L with a high negative (93%) but low positive predictive value (19%). In secondary analyses, elevated Lp(a) was also independently associated with LAA-stroke. Conclusions Elevated Lp(a) levels are associated with sICAS and LAA-stroke. In contrast, Lp(a) concentrations <53 nmol/L are associated with a low likelihood of sICAS, supporting consideration of alternative AIS etiologies. Conflict of interest None of the contributing authors has conflicts of interest to disclose.