Abstract
Background:
Cervical internal carotid artery (ICA) tortuosity has been associated with vascular risk and stroke as well as genetic disorders related to abnormal extracellular matrix remodeling. It is plausible that dystrophic or aberrant arterial remodeling may therefore relate to cervical ICA tortuosity. We hypothesized that cervical ICA tortuosity relates to carotid dilatation, but not to traditional ultrasound (US) markers of atherosclerosis.
Methods:
Subjects of the NOMAS with available time-of-flight MRA were included in our study. Cervical ICA tortuosity was defined as a bend in the distal cervical ICA of > 90° as seen on MRA. We excluded subjects with < 5 cm of the cervical ICA visualized. Distensibility was calculated as the percentage excursion of the right CCA diastolic diameter during systole, which was assessed by high-resolution B-mode US of the right common carotid artery (CCA). We used multivariable logistic regression analyses to estimate odds ratios for the association of cervical ICA tortuosity and Doppler measures of carotid wall aging.
Results:
We visualized cervical ICA tortuosity in 468 NOMAS participants (mean age 64±8 years, 70% women, 70% Hispanic). It was present in 23% of subjects. In unadjusted models, cervical ICA tortuosity was more common in women (OR 2.34, 95% CI 1.34-4.11), Hispanics (OR 1.85, 95%CI 1.06-3.25) and those with higher diastolic blood pressures (OR per mm Hg 1.04, 95%CI 1.01-1.06), and less common among smokers (OR 0.23, 95%CI 0.07-0.78). In models adjusted for demographic and vascular risks, right CCA tortuosity was associated with ipsilateral larger CCA DD (OR 1.42, 95%CI 1.02-1.96) and borderline associated with lower distensibility (OR 0.94, 95%CI 0.87-1.01, P=0.06) but not with ipsilateral ICA IMT (OR 0.26, 95%CI 0.14-4.77), number of plaques (OR 1.08, 95%CI 0.76-1.53), maximum plaque thickness (OR 0.96, 95%CI 0.73-1.27), or plaque area (1.00, 95%CI 0.97-1.05).
Conclusions:
Cervical ICA tortuosity associates with ipsilateral cervical ICA dilatation and lower distensibility, but not with traditional US markers of atherosclerosis. The association with diastolic blood pressure suggests a role of steady, rather than pulsatile, hemodynamics in aberrant cervical ICA remodeling.