Higher Degree of Carotid Artery Stenosis is Associated with Worse Cognition
Michelle Lin1, Nihas Mateti1, Young Erben 2, Kevin Barrett1, Nilufer Taner1, Thomas Brott1, James Meschia1
1Neurology, 2Vascular Surgery, Mayo Clinic
Objective:
To test the hypothesis that severity of carotid stenosis is inversely correlated with cognitive measures.
Background:
Studies have suggested that ischemic stroke from carotid stenosis may lead to cognitive impairment. However, the relationship between the degree of carotid stenosis and cognition has not been established.
Design/Methods:
We performed a cross-sectional study across one health care system, assessing patients with carotid Duplex ultrasound and the Montreal Cognitive Assessment (MoCA) that were done within one year from 2018 to 2022. Carotid stenosis was defined using Doppler velocity parameters as <50% normal, 50-69% moderate, 70-99% high-grade, and occluded. Cognition was quantified using MoCA where cognitive impairment was defined as MoCA <18. Multivariable regression analyses were performed to evaluate the linear relationship between carotid stenosis parameters and MoCA, and the odds of cognitive impairment across severity of carotid stenosis. Interaction analyses by age and stroke were performed.
Results:
Of 1,172 patients included in the study, 73.0%, 16.8%, 8.4% and 1.8% had normal, moderate, high-grade, and occluded carotids. Mean age was 73±12 years, 41.5% were female, 17.1% had prior stroke. ICA/CCA ratio was inversely associated with MoCA scores (β-coefficient=-0.362, p=0.010). Mean MoCA decreased with increasing degree of carotid stenosis (normal=20.8, moderate=20.4, high-grade=19.4, occluded=18.7;trend-p=0.021). There was a dose-dependent relationship between degree of carotid stenosis and cognitive impairment: Adjusted odds of cognitive impairment were 1.31, 2.14, 2.73 across patients with moderate, high-grade and occluded carotids (trend-P=0.016). Interaction analyses showed that age modified the relationship between carotid stenosis and cognition (p=0.003) where the association was observed in patients age ≥65 years (aOR=3.04,p=0.001) but not in age<65 years (aOR=0.46,p=0.175). No interaction was observed with stroke.
Conclusions:
Our study showed an inverse relationship between degree of carotid stenosis and cognition, particularly in patients 65 years or older. Future trials may consider testing whether carotid revascularization may prevent further cognitive decline in selected populations.