ABSTRACT NUMBER: ESOC2026A680 SPEED OF INFARCT PROGRESSION AS A METRIC IS ASSOCIATED WITH OUTCOME AND ENDOVASCULAR TREATMENT BENEFIT IN PROGRESSIVE ISCHEMIC STROKE WITH ANTERIOR CIRCULATION LARGE VESSEL OCCLUSION

Abstract Background and aims Current evaluation of progressive ischemic stroke (PIS) with anterior circulation large vessel occlusion (ALVO) relies on static clinical or imaging measures and lacks quantitative assessment of dynamic neurological deterioration. We propose a novel metric, the speed of infarct progression (SIP), and explore its clinical value. Methods We retrospectively enrolled consecutive ALVO-PIS patients treated at our center between January 2022 and June 2025, restricted to large-artery atherosclerosis. SIP was derived from NIHSS change and progression time using a mathematically adjusted ratio.The primary endpoint was unfavorable outcome at 90 days (mRS 3–6). We analyzed the association between SIP and outcomes, evaluated EVT treatment effects, and explored relationships between SIP and disease course–related factors. Results In a total of 142 patients, 50.0%(71/142) had a poor 90-day outcome, 57.0%(81/142) received EVT. Regression analysis identified SIP as an independent risk factor for poor outcome (OR 1.233, 95% CI 1.082-1.404; P=0.002). Adding SIP to a baseline model with traditional clinical variables improved discrimination (AUC 0.687 to 0.766; DeLong P=0.065). In treatment-effect analyses, lower SIP was associated with greater absolute benefit from EVT. Absolute risk reduction (ARR) was approximately 30% at SIP ≈11 and 10% at SIP ≈20 (Figure 1A). Exploratory analyses showed overall higher SIP in early than delayed progression, with poor outcomes clustering in regions of high SIP and poor collateral status (Figure 1B). Conclusions SIP is an independent prognostic risk factor in ALVO-PIS that captures the dynamics of disease and heterogeneity in EVT benefit, suggesting involvement in treatment decision-making,pending further validation. Conflict of interest Bang Liu :: nothing to disclose. GUODONG XU : nothing to disclose. QIshuo Yang : nothing to disclose. Ning Han: nothing to disclose. Kuochang YIN: nothing to disclose. Liang Ma: nothing to disclose. Wentao Yao: nothing to disclose. Yanzhao Xie: nothing to disclose.Qiang Sun: nothing to disclose.Xueqian Zhang: nothing to disclose.Yan Zhao: nothing to disclose.Yazhao Zhang: nothing to disclose.Xianghe Meng: nothing to disclose. Figure 1 - belongs to Results