ABSTRACT NUMBER: ESOC2026A1727 LOW HDL CHOLESTEROL LEVELS AND ALTERED LDL MODIFICATION-RELATED PARAMETERS PREDICT ADVERSE OUTCOMES IN PATIENTS WITH CAROTID ATHEROSCLEROSIS

Abstract Background and aims Lipoprotein composition and function are altered in ischaemic stroke associated with carotid atherosclerosis. We aimed to evaluate the prognostic value of HDL and LDL quality parameters for mortality and major adverse cardiovascular events (MACE) in patients with carotid atherosclerosis. Methods A prospective observational study of patients with ≥50% internal carotid artery stenosis undergoing carotid endarterectomy from 2020 to 2023 was performed. The cohort included 62 symptomatic patients (Sx; recent stroke) and 32 asymptomatic patients (Asx; no stroke within 6 months). All patients were followed for 1 year. Serum lipid profile and lipoprotein composition (autoanalyzer), LDL resistance to oxidation (conjugated diene kinetics), and aggregated LDL (chromatography) were assessed. A three-point MACE definition was used including stroke, myocardial infarction, and vascular death. Cox regression analyses were conducted to assess association with mortality and MACE. Results No differences were found in lipid profile and other parameters between Sx and Asx, except for lower apoA-I levels in Asx. Reduced resistance of LDL to oxidation and increased susceptibility to aggregation were associated with higher mortality independently of stenosis degree (aHRx1 min-increase=0.71, p=0.024; aHRx1 %-increase=1.05, p=0.017, respectively). Serum HDL cholesterol was inversely associated with MACE (HRx1 mmol/L-increase=0.02, p=0.024). However, triglyceride content in HDL was positively associated with MACE in multivariable analyses (aHRx1 %-increase=2.13, p<0.001). Conclusions In patients with significant carotid stenosis, increased LDL susceptibility to oxidation and aggregation are associated with higher mortality, while low HDL cholesterol and triglyceride-enriched HDL seem to predict MACE during the follow-up. Our results highlight the relevance of lipoprotein quality beyond lipid profile. Conflict of interest All author: nothing to disclose