Antegrade Blood Flow on 4‐Dimensional Computed Tomography Angiography Predict Stroke Subtype in Patients With Acute Large Artery Occlusion

BACKGROUND: The purpose of this study was to determine whether the presence of antegrade blood flow was related to stroke subtype in patients with acute intracranial large artery occlusion. METHODS AND RESULTS: The prospectively collected data for consecutive patients who had occlusion of the unilateral M1 segment of the middle cerebral artery with or without internal carotid artery and received reperfusion therapy were retrospectively reviewed. Stroke causes were determined according to the Trial of ORG 10172 in Acute Stroke Treatment standard. We defined antegrade flow as early opacification at the distal interface of the clot with subsequent distal extension on 4‐dimensional computed tomography angiography. A total of 387 large artery occlusion patients were analyzed (229 men and 158 women; mean age, 71±14 years), including 77 (19.9%) with large artery atherosclerosis (LAA), 206 (53.2%) with cardioembolism, and 104 (26.9%) with undetermined causes. Antegrade flow was found in 206 (53.2%) patients, and 181 (46.8%) presented with retrograde flow. The rate of antegrade flow was much higher in patients with LAA than in those with cardioembolism (85.7% versus 42.2%, P<0.001). Multivariable logistic regression revealed that presence of antegrade flow was significantly associated with cuse of LAA after adjusting for confounding factors, when setting cardioembolism as reference (odds ratio, 5.650; 95% confidence interval, 2.451–13.158; P<0.001). The sensitivity, specificity, and positive and negative predictive values of the antegrade flow for predicting LAA were 43.1%, 91.5%, 85.7%, and 57.8%, respectively. CONCLUSIONS: Using 4‐dimensional computed tomography angiography, antegrade flow can be identified in more than half of acute anterior large artery occlusion patients and occurs more frequently in those with LAA as the cause of stroke.