Abstract WP174: Elevated Homocysteine Intensify The Effect Of Lipoprotein(a) On Stroke Recurrence

Abstract

Introduction: Lipoprotein(a) [Lp(a)] and homocysteine (tHcy) are risk factors for ischemic stroke. tHcy show great impact on Lp(a) binding to fibrin and interaction between Lp(a) and Mac-1 integrin, which might intensify the atherogenic and thrombotic pathway mediated by Lp(a). The study aims to explore the effect of Lp(a) on stroke recurrence within 1 year in patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA), based on different tHcy level. Method: A total of 10068 patients with AIS or TIA from the third China National Stroke Registry cohort were included. Since Lp(a) levels vary strongly between ethnicities, the cut-off value was set at the 80 th percentile based on National Lipid Association recommendation. The association between Lp(a) and stroke recurrence was evaluated using Cox proportional hazards model. Patients were further categorized to five different subtypes according to the TOAST criteria. The interaction between Lp(a) and tHcy was tested in different subtypes. Result: 8054 patients were classified into the ≤80 th group, 2014 patients were classified into the >80 th group. No significant differences were found between the two groups in terms of age, sex, and traditional risk factors (P>0.05). 999 patients experienced recurrent stroke in 1 year follow-up. Patients with Lp(a)>80 th patients had a higher risk of stroke recurrence (11.57% vs 9.51%). Patients were further stratified by tHcy (>15 and ≤15 μmol/L). Among all patients, the highest recurrence rate (12.8%) was observed in the patients with elevated both Lp(a) and tHcy (aHR 1.41; 95%CI 1.14-1.74), the interaction between Lp(a) and tHcy was observed (P=0.03). We also found significant interaction among large-artery atherosclerosis (LAA) subtype (P<0.01). Conclusion: The finding indicated elevated tHcy might intensify Lp(a)-associated stroke recurrence. Elevated Lp(a) should receive more attention in AIS/TIA patients with elevated tHcy, especially in the LAA subtype.