Stroke etiology and collaterals: atheroembolic strokes have greater collateral recruitment than cardioembolic strokes

• Published in: European journal of neurology Vol. 24; no. 6; pp. 762 - 767
• Main Authors: Rebello, L. C., Bouslama, M., Haussen, D. C., Grossberg, J. A., Dehkharghani, S., Anderson, A., Belagaje, S. R., Bianchi, N. A., Grigoryan, M., Frankel, M. R., Nogueira, R. G.
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01-06-2017
• Subjects: Aged; Aged, 80 and over; Angiography; Arterial Occlusive Diseases - complications; Arterial Occlusive Diseases - diagnostic imaging; Arterial Occlusive Diseases - physiopathology; Arteriosclerosis; Atherosclerosis; brain imaging; Cardiac arrhythmia; Cardiovascular system; Cerebral Angiography; Circulation; Collateral; collateral circulation; Collateral Circulation - physiology; Computed tomography; Confidence intervals; Embolism; endovascular treatment; Etiology; Female; Fibrillation; Hemorrhage; Humans; Intracranial Embolism - complications; Intracranial Embolism - diagnostic imaging; Intracranial Embolism - physiopathology; ischaemia; Lesions; Male; Males; Middle Aged; Occlusion; Patients; Perfusion; Retrospective Studies; Smoking; Stroke; Stroke - diagnostic imaging; Stroke - etiology; Stroke - physiopathology; brain imaging; collateral circulation; ischaemia; endovascular treatment; stroke
• ISSN: 1351-5101; 1468-1331
• DOI: 10.1111/ene.13287

Background and purpose
Chronic hypoperfusion from athero‐stenotic lesions is thought to lead to better collateral recruitment compared to cardioembolic strokes. It was sought to compare collateral flow in stroke patients with atrial fibrillation (AF) versus stroke patients with cervical atherosclerotic steno‐occlusive disease (CASOD).
Method
This was a retrospective review of a prospectively collected endovascular database. Patients with (i) anterior circulation large vessel occlusion stroke, (ii) pre‐treatment computed tomography angiography (CTA) and (iii) intracranial embolism from AF or CASOD were included. CTA collateral patterns were evaluated and categorized into two groups: absent/poor collaterals (CTA collateral score 0–1) versus moderate/good collaterals (CTA collateral score 2–4). CT perfusion was also utilized for baseline core volume and evaluation of infarct growth.
Results
A total of 122 patients fitted the inclusion criteria, of whom 88 (72%) had AF and 34 (27%) CASOD. Patients with AF were older (P < 0.01) and less often males or smokers (P = 0.04 and P < 0.01 respectively). Baseline National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT Score were comparable between groups. Collateral scores were lower in the AF group (P = 0.01) with patients having poor collaterals in 28% of cases versus 9% in the CASOD group (P = 0.03). Mortality rates (20% vs. 0%; P = 0.02) were higher in the AF patients whilst rates of any parenchymal hemorrhage (6% vs. 26%; P < 0.01) were higher in the CASOD group. On multivariable analysis, CASOD was an independent predictor of moderate/good collaterals (odds ratio 4.70; 95% confidence interval 1.17–18.79; P = 0.03).
Conclusions
Atheroembolic strokes seem to be associated with better collateral flow compared to cardioembolic strokes. This may in part explain the worse outcomes of AF‐related stroke.