Abstract DP138: Composite Arterial and Venous Collateral Score on Single-Phase CTA Predicts 90-Day Outcomes in Anterior Circulation Large-Vessel Occlusion Stroke

Background: Collateral circulation influences clinical outcomes in patients with acute ischemic stroke due to anterior circulation large-vessel occlusion (LVO). While both arterial and venous collateral assessments on single-phase CTA have prognostic value, they have traditionally been evaluated independently. Purpose: We developed the CTA Collateral Impairment Score (CCIS), a composite measure incorporating arterial (Tan) and venous (COVES) scores, and investigated its association with 90-day functional outcomes. Materials and Methods: We conducted a retrospective cohort study including 1,080 patients with anterior circulation LVO stroke across four comprehensive stroke centers. Patients were assigned a CCIS of 0 (preserved), 1 (moderate impairment), or 2 (severe impairment) based on predefined thresholds for Tan and COVES scores. Results: Favorable outcomes (mRS 0–2) occurred in 66% of patients with CCIS 0, 32% with CCIS 1, and 17% with CCIS 2 (p