Abstract W P367: Anterior Cerebral Artery Diameter Predicts Anterior Cerebral Artery Territorial Stroke.

Abstract

Background: Anterior cerebral artery strokes (ACAS) account for only 1-2% of cerebral infarctions, and typically result from embolism in western populations. The cause of the low frequency of ACAS in relation to MCA strokes (MCAS) is uncertain, but differences in arterial anatomy may affect flow-directed embolism rates. We aimed to determine whether variability in ACA A1 diameters (A1D) and A1D/MCA M1 diameter (M1D) ratios predict ACAS Methods: Consecutive patients admitted to Boston Medical Center with a diagnosis of ACAS between 01/2008-10/2012 were reviewed. Patients with an interpretable CT angiogram (CTA) or magnetic resonance angiogram (MRA) of the cerebral vasculature were eligible. Excluded were patients with ACAS ipsilateral (ipsi) to an aplastic ACA, concomitant ipsi MCAS, and those with lacunar, watershed, aneurysm clipping or local intracranial atherosclerosis as stroke etiology. Patient demographics were compiled. Ipsilateral and contralateral (contra) A1D, M1D, as well as ICA-ACA and ICA-MCA angles were measured from CTA and MRA images. Consecutive MCAS admitted between 01/2011-10/2012 served as controls. Results: The study comprised 55 individuals (27 ACA, 28 MCA) with mean age of 69 years. Stroke etiology was cardioembolism in 56%, internal carotid artery embolism in 16% and idiopathic in 27%. Patients with ACAS had larger mean ipsi A1D (2.47 vs. 2.05 mm,p<0.01), ipsi A1D/M1D ratios (0.95 vs. 0.73,p<0.001) and were more likely to have a contra aplastic/hypoplastic ACA (41 vs. 4%,<0.001). Ipsi A1D (OR per 1 mm increment: 8.52 [95% CI 1.36, 53.26]) and ipsi A1D/M1D ratio (OR per 10% increment: 1.83 [95% CI 1.15, 2.91]) remained significant following multivariate analysis. Ipsilateral M1D was protective for ACAS (OR per 1 mm increment: 0.17 [95% CI 0.03, 0.90]) after adjusting for ipsi A1D. There were no significant differences in demographic variables, stroke etiologies, terminal ICA-ACA or ICA-MCA angles between ACAS and MCAS. Conclusions: Larger ipsilateral A1D and A1D/M1D ratio are independent predictors of ACAS. These findings concur with the notion that A1D and M1D are important in determining the path of emboli that reach the terminal ICA.