Abstract WP166: Factors Associated with Proximal Carotid Axis Occlusion in Patients with Acute Stroke and Atrial Fibrillation

Abstract

Background and purpose Patients with atrial fibrillation (AF) are more likely to exhibit proximal carotid axis occlusion than those without AF. However, clinical characteristics associated with proximal vessel occlusion (PVO) in acute stroke patients with AF are not fully known. This study was aimed to elucidate the factors correlated with PVO. Methods Consecutive patients with acute ischemic stroke in the anterior circulation and AF who underwent MRA within 24 h from onset were retrospectively enrolled. Prior users of warfarin were excluded. Patients were divided into 3 groups based on the site of arterial occlusion: occlusion at the internal carotid artery (ICA); at the horizontal segment of the middle cerebral artery (MCA, M1); and at the MCA branch or no identifiable occlusion. Clinical characteristics were compared between the 3 groups, and the factors associated with proximal vessel occlusion were evaluated with ordinal logistic regression analysis. All variables identified on univariable analyses with p values <0.1 were entered into the model. Results A total of 258 patients (127 women, median 80 years old [interquartile range 71-86], median NIHSS score was 15 [6-21]) were studied. MRA was performed median 2.9 h [1.6-10.3] after stroke onset. Occlusion site was the ICA in 34 patients, M1 in 78, and MCA branch or no occlusion in the remaining 146. As the occlusion site was more proximal, patients were older and more female, the initial NIHSS score was higher, levels of D-dimer and brain natriuretic peptide (BNP) were higher, and histories of heart failure and systemic embolism were more common. On multivariable ordinal logistic regression analysis, female sex (OR 2.02, 95%CI 1.15-3.56), advanced age (OR 1.37, 95%CI 1.02-1.85 for every 10 years), history of systemic embolism (OR 15.3, 95%CI 1.45-161), and higher BNP level (OR 1.04, 95%CI 1.01-1.09 for every 50 pg/ml) were independent factors associated with increasing the risk of shifting to a more proximal vessel occlusion category. Conclusion Female sex, advanced age, history of systemic embolism, and higher BNP level were independently associated with more proximal carotid axis occlusion. Patients with AF having these factors may be prone to have larger thrombus in the heart than those without.