ABSTRACT NUMBER: ESOC2026A2150 ASSOCIATION OF ELEVATED LIPOPROTEIN(A) WITH CLINICAL AND IMAGING OUTCOMES IN INTRACRANIAL ARTERIAL STENOSIS: ANALYSIS OF THE PROSPECTIVE BERNESE INTRACRANIAL STENOSIS STUDY (BISS)

Abstract Background and aims Elevated lipoprotein(a) (Lp(a)) is an established risk factor for atherosclerosis. However, its role in intracranial atherosclerotic stenosis (ICAS) remains unclear. 7-Tesla-MRI enables detailed ICAS assessment. Methods We analyzed 162 ≥50%-ICAS patients (n=84 symptomatic) with best medical management from the prospective Bernese Intracranial Stenosis Study, stratified by Lp(a) levels into normal/moderately elevated (<125 nmol/L; n=127) and markedly elevated (≥125 nmol/L; n=35) groups. Associations with risk factors, 3/7T-MRI, and outcome were assessed. Results No significant differences were found between Lp(a) groups and ICAS burden/location (p=0.198/0.709), and most risk factors. Atrial fibrillation was more frequent in the markedly elevated Lp(a) group (16.7% vs.10%; p=0.021) in asymptomatic patients. Markedly elevated Lp(a) was associated with more severe cerebral microangiopathy (p=0.042). Higher Lp(a) levels were linearly associated with poorer functional outcome (mRS) at discharge (p=0.003). 1-year excellent outcome (mRS:0-1) was more frequent in asymptomatic patients (52.1% vs.34.5%; p=0.044), showing a trend (p=0.093) in the normal/moderate Lp(a) group only. 1-year ischaemic strokes (13.6% vs. 0%;p=0.001) occurred in the symptomatic group only. A favorable evolution of 1-year ICAS contrast-enhancement dynamics was more frequent in asymptomatic patients overall (p=0.001) and among patients with normal/moderately elevated Lp(a) levels (p=0.031). Conclusions Markedly elevated Lp(a) in ICAS patients was not associated with ICAS burden/location but with atrial fibrillation, more severe cerebral microangiopathy, and poorer functional outcome at discharge, suggesting Lp(a) may enhance risk stratification in this patient group. Conflict of interest All authors: nothing to disclose.