Combined assessment of ASPECTS and collateral status predict outcomes after endovascular therapy in patients with large ischemic stroke.

BACKGROUND: Both the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and collateral status are well-established predictors of clinical outcomes in patients with large ischemic stroke undergoing endovascular therapy (EVT); however, they have traditionally been assessed independently. This study aimed to evaluate the prognostic value of a combined imaging score, the AS-TCIS score, which integrates ASPECTS and collateral status into a unified framework. METHODS: This study is a subanalysis of a prospective multicenter cohort including patients with ASPECTS ≤5 enrolled between November 2021 and February 2023. The AS-TCIS score was constructed by integrating the 5-point ASPECTS with collateral status, including the 3-point Tan score and the 8-point comprehensive venous outflow (CVO) score, yielding a 16-point composite scale. The primary outcomes were 90-day functional outcome (modified Rankin Scale [mRS] 0-3) and mortality. RESULTS: Of 750 patients, 287 were eligible (median age 67 years; 58.5% male; median AS-TCIS score 8). In multivariable models, each 1-point increase in AS-TCIS was associated with higher odds of mRS 0-3 (OR 1.38; 95% CI 1.24-1.56) and mRS 0-2 (OR 1.30; 95% CI 1.17-1.47), and lower odds of mortality (OR 0.74; 95% CI 0.66-0.82), with no significant association with symptomatic intracranial hemorrhage (OR 0.92; 95% CI 0.82-1.03). AS-TCIS also demonstrated a linear association with functional outcome and mortality. Compared with ASPECTS, Tan score, and their combination, AS-TCIS showed consistently higher AUCs and improved model fit across all outcomes. CONCLUSION: The AS-TCIS score, a composite of ASPECTS and collateral status, was independently associated with 90-day outcomes in patients with large ischemic stroke undergoing EVT. It may provide incremental value for risk stratification and outcome prediction in acute stroke imaging assessment.