Abstract Body: Introduction
Carotid artery tortuosity, characterized by abnormal vessel twisting, has been reported to be associated with various vascular pathologies and the presence of stroke. We aimed to evaluate the association between carotid artery tortuosity and the incidence of ischemic stroke.

Methods
We analyzed 3D contrast-enhanced MRA datasets from 2,066 participants enrolled in the Atherosclerosis Risk in Communities (ARIC) Carotid MRI study. Of these, 368 were excluded due to prevalent stroke, missing covariates, or missing/uninterpretable contrast-enhanced MRA data. Tortuosity was qualitatively evaluated using the Weibel method¹, categorized into three types (tortuosity, kinking, and coiling), and quantitatively measured using LAVA software as distance and angle metrics (Figure 1)². The association between carotid tortuosity, a time-dependent exposure variable, and incident ischemic stroke was evaluated using Cox regression models adjusted for demographic and cardiovascular risk factors.

Results
Among the 1,698 participants (71.51±0.44 years, 51.7% women; 22.1% Black), 135 had an ischemic stroke over a median follow-up of 8.6 years. The Kaplan-Meier plot demonstrated that the coiling type was associated with an increased rate of stroke compared to other groups (Figure 2). Tortuosity metrics validated the significant difference between two groups (mean distance matrix tortuosity: 1.66 ± 0.31 for coiling vs. 1.21 ± 0.18 for non-coiling, p<0.001). Cox regression analysis showed that the presence of carotid artery coiling was associated with a 2.5-fold increased risk of ischemic stroke (95% CI, 1.08-5.61) compared to those without coiling, after adjusting for age, sex, race and cardiovascular risk factors (smoking, hypertension, diabetes mellitus, and statin use).


Conclusion
Carotid artery tortuosity (i.e., coiling) is associated with incidence ischemic stroke, suggesting its potential as an imaging morphological marker for predicting future cerebrovascular events.

References:
1. Weibel J, et. al, . Neurology. 1965 Jan;15:7-18.
2. Zhou S, et.al,. J Magn Reson Imaging. 2024;59(5):1612-1619.