ABSTRACT NUMBER: ESOC2026A973 POINT-OF-CARE BIOMARKERS TO ESTIMATE EXTENT OF ISCHEMIC DAMAGE IN ACUTE ISCHEMIC STROKE DUE TO LARGE-VESSEL OCCLUSION

Abstract Background and aims Point-of-care biomarkers may complement neuroimaging in acute ischemic stroke due to large-vessel occlusion (AIS-LVO). We evaluated whether rapid plasma levels of glial fibrillary acidic protein (GFAP) and Ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1) provide insights into the extent of early ischemic changes in AIS-LVO. Methods Exploratory analysis of a prospective study of AIS-LVO participants presenting to the emergency department (ED) <24h from onset. Ischemic changes were assessed by ASPECTS on non-contrast CT at ED arrival. Plasma GFAP and UCH-L1 levels (pg/ml) were measured using the iSTAT Alinity System. Biomarker levels were compared between extensive (ASPECTS <8) and limited (ASPECTS 8-10) ischemia groups using Mann-Whitney U test and ROC analysis. Results Among 102 participants, mean age was 75.9±12.9 years, 53.9% female, median(IQR) NIHSS 18(12-23), and baseline ASPECTS 8(7-10). ED GFAP levels were significantly higher in those with extensive (n=31) vs. limited ischemia (n=71) (78(41-187) vs. 47(29-74), p=0.004). However, ROC analysis demonstrated modest discriminatory ability (AUC=0.68(95%CI(0.56-0.79)), optimal cut-off 69.5 pg/mL (SN=55%, SP=73%, J=0.28). Median UCH-L1 levels were comparable between groups (316(199-569) vs. 227(199-362) p=0.13). Neither biomarker varied across predefined time windows from onset subgroups (≤4.5hrs, ≤6hrs, 6-12hrs, 12-24hrs, all p>0.05). Weak correlations were observed between time from onset (known or LSW). and GFAP (r=0.252, p=0.01) and UCH-L1(r=0.219, p=0.03). Conclusions While GFAP levels differ among AIS-LVO participants with extensive ischemia compared to limited ischemia, discrimination is modest suggesting insufficient accuracy for clinical decision-making as a standalone tool, yet may warrant further investigation in larger cohorts. Conflict of interest Gioia LC: Funding for study provided by the Heart and Stroke Foundation of Canada, nothing to disclose for other authors