ASSOCIATION OF CT ANGIOGRAPHIC COLLATERAL STATUS WITH STROKE SEVERITY AND FUNCTIONAL OUTCOMES IN PATIENTS WITH ACUTE ANTERIOR CIRCULATION ISCHEMIC STROKE: A PROSPECTIVE COHORT STUDY

Abstract

Background: Cerebral collateral circulation plays a crucial role in maintaining cerebral perfusion and limiting ischemic injury following acute arterial occlusion. Computed tomography angiography (CTA) enables noninvasive assessment of collateral circulation and may provide valuable prognostic information regarding stroke severity and functional recovery. Objective: To evaluate the association of CTA collateral status with admission stroke severity, early neurological improvement, and 90-day functional outcomes in patients with acute anterior circulation ischemic stroke. Methods: This Multicenter prospective cohort study included 150 patients with acute anterior circulation ischemic stroke enrolled between January 2025 and January 2026 at District Headquarters Hospital, Nankana Sahib, and Allied Hospital, Faisalabad, affiliated with Faisalabad Medical University, Pakistan. CTA collateral status was classified as good (grades 2–3) or poor (grades 0–1). Clinical assessments included the National Institutes of Health Stroke Scale (NIHSS), Alberta Stroke Program Early CT Score (ASPECTS), early neurological improvement, symptomatic intracranial hemorrhage, and 90-day modified Rankin Scale (mRS). Multivariable logistic regression was used to identify factors associated with functional independence (mRS 0 2). Results: Of 150 patients, 86 (57.3%) exhibited good collateral circulation and 64 (42.7%) had poor collateral circulation. Patients with good collaterals demonstrated significantly lower median NIHSS scores (12 vs. 18; P<0.001) and higher median ASPECTS scores (8 vs. 7; P<0.001). Functional independence at 90 days was significantly greater in the good-collateral group (69.8% vs. 26.6%; P<0.001). Early neurological improvement occurred in 62.8% versus 32.8%, respectively, while 90-day mortality was lower (3.5% vs. 15.6%). After adjustment for age, NIHSS, ASPECTS, occlusion location, and endovascular thrombectomy, good collateral circulation remained significantly associated with functional independence (adjusted odds ratio: 2.79; 95% CI: 1.17–6.65; P=0.021). Conclusion: Favorable CTA collateral status was independently associated with reduced stroke severity and improved neurological and functional outcomes at 90 days. CTA collateral assessment represents a valuable complementary imaging marker for prognostic evaluation in acute anterior circulation ischemic stroke.