Internal Carotid Artery Angle Variations are Poorly Explained by Vascular Risk Factors: The Northern Manhattan study

• Published in: Journal of stroke and cerebrovascular diseases Vol. 31; no. 8; p. 106540
• Main Authors: Del Brutto, Victor J., Dong, Chuanhui, Cullison, Kaylie, Caunca, Michelle R., Simonetto, Marialaura, Cabral, Digna E., Gutierrez, Jose, Elkind, Mitchell S.V., Sacco, Ralph L., Rundek, Tatjana
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2022
• Subjects: Aged; Atherosclerosis; Carotid Arteries - diagnostic imaging; Carotid artery disease; Carotid Artery, Common - diagnostic imaging; Carotid Artery, Internal - diagnostic imaging; Carotid geometry; Carotid Intima-Media Thickness; Carotid ultrasound; Female; Humans; Male; Middle Aged; Plaque, Atherosclerotic; Risk Factors; Vascular risk factors; Carotid geometry; Carotid artery disease; Vascular risk factors; Carotid ultrasound
• ISSN: 1052-3057; 1532-8511
• DOI: 10.1016/j.jstrokecerebrovasdis.2022.106540

•Internal carotid artery (ICA) angle has been shown to influence hemodynamics and is proposed as a potential contributor of atherogenesis and risk of stroke.•In our multiethnic cohort of stroke-free individuals, left ICA angle was significantly narrower compared to the right side.•Advanced age and Black race were correlated with unfavorable ICA angles bilaterally.•Overall, demographics and vascular risk factors explained less than 10% of ICA angle of origin variance. The internal carotid artery (ICA) angle of origin may contribute to atherogenesis by altered hemodynamics. We aim to determine the contribution of vascular risk factors and arterial wall changes to ICA angle variations. We analyzed 1,065 stroke-free participants from the population-based Northern Manhattan Study who underwent B-mode ultrasound (mean age 68.7±8.9 years; 59% women). ICA angle was estimated at the intersection between the common carotid artery and the ICA center line projections. Narrower external angles translating into greater carotid bifurcation bending were considered unfavorable. Linear regression models were fitted to assess the relationship between ICA angle and demographics, vascular risk factors, and arterial wall changes including carotid intima-media thickness (cIMT) and plaque presence. ICA angles were narrower on the left compared to the right side (153±15.4 degrees versus 161.4±12.7 degrees, p<0.01). Mean cIMT was 0.9±0.1 mm and 54.3% had at least one plaque. ICA angle was not associated with cIMT or plaque presence. Unfavorable left and right ICA angles were associated with advanced age (per 10-year increase β=-1.6; p=0.01, and -1.3; p=0.03, respectively) and being Black participant (β=-4.6; p<0.01 and -2.9; p=0.04, respectively), while unfavorable left ICA angle was associated with being female (β=-2.8; p=0.03) and increased diastolic blood pressure (per 10 mmHg increase β=-2.1; p<0.01). Overall, studied factors explained less than 10% of the variance in ICA angle (left R2=0.07; right R2=0.05). Only a small portion of ICA angle variation were explained by demographics, vascular risk factors and arterial wall changes. Whether ICA angle is determined by other environmental or genetic factors, and is an independent risk factor for atherogenesis, requires further investigation.