ABSTRACT NUMBER: ESOC2026A1227 EARLY EXTENSIVE INFARCTION ON BASELINE CT IN ACUTE ISCHEMIC STROKE: CLINICAL CHARACTERISTICS AND OUTCOMES AFTER REPERFUSION THERAPY

Abstract Background and aims Fast Early Infarct (FEI) in acute ischemic stroke is associated with poor collaterals, may be associated with poor prognosis and it has been primarily characterized using perfusion imaging. Given that non-contrast CT is the most widely available modality in the early time window, we aimed to characterize patients with FEI defined on baseline CT, compare them with non-FEI patients, and identify factors associated with poor outcome within this phenotype. Methods We conducted a retrospective observational study including every patient with anterior circulation acute ischemic stroke after endovascular treatment between 2022 and 2025 in Aragon, Spain. We compared clinical characteristics and outcome between patients with ASPECTS ≤7 on baseline non-contrast CT within 3 hours from symptom onset (FEI) vs within ≥6hours from symptom onset (non-FEI). Within FEI patients, factors associated with poor functional outcome at 3 months (mRS 3-6) were assessed using multivariable logistic regression. Results We included 116 patients; 82 (70.7%) presented FEI. FEI patients were more frequently male (78.4% vs 57.14%; p=0.016) and had higher median baseline NIHSS (18 vs 16; p=0.04). Good functional outcome at 3 months was more frequently reached in patients with FEI (mRS 0–2: 38.7% vs 34.4%), without reaching statistical significance (p=0.674). There was no difference in mortality within groups (28.0% vs 28.12%). Among FEI patients, baseline NIHSS was the only independent predictor of poor functional outcome at 3 months (OR 1.13, CI 95% 1.02–1.25). Conclusions Despite higher baseline NIHSS, patients with FEI showed similar functional outcomes and mortality compared with those without FEI. Conflict of interest Laura Ramos Barrau: nothing to disclose. Herbert Tejada Meza: nothing to disclose. Javier Marta Moreno: nothing to disclose.