Cognitive Impairment Under-Recognized in Patients With Asymptomatic Carotid Stenosis

Cognitive impairment is an under-recognized morbidity among patients with asymptomatic carotid stenosis (ACS) and may result from impaired cerebral hemodynamics, according to a study in the Journal of Vascular Surgery.

Researchers conducted a systematic review to assess the literature on cerebrovascular hemodynamics in patients with ACS and their effect on cognitive functioning.¹

A search was performed in the MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases through May 2022 for prospective case-control studies that included adults aged 18 years or older with unilateral or bilateral ACS, a control group, and a validated, objective measure of global cognitive function or 1 or more domains of cognitive function separately.

The review included 5 studies with 782 patients and 407 control individuals. Among the studies, 4 were cross-sectional and 1 provided longitudinal data for 3 years of follow-up.

All included studies used the breath-holding index to evaluate cerebrovascular reactivity, and substantial heterogeneity was observed in the use of neuropsychologic assessments to assess cognitive performance.

All 5 studies found a significant association between unilateral and/or bilateral ACS and cognitive impairment, and 4 studies reported a significant association between a reduction in cerebrovascular reserve and impaired cognitive function in patients with unilateral ACS. The participants with ACS and reduced cerebrovascular reserve had significantly decreased global and domain-specific cognitive performance, and the lowest cognitive scores occurred in patients with bilateral stenosis and cerebrovascular reserve reduction.

In the 1 longitudinal study, Balestrini et al² evaluated progressive cognitive decline in patients with unilateral ACS vs control individuals during a 3-year period. Cognitive deterioration, based on a 3-point reduction in Mini-Mental State Examination scores, occurred in 24.8% of patients with ACS (unilateral stenosis, 70%-99%) compared with 7% of age-matched control individuals. The study authors found a significant association between impaired ipsilateral cerebrovascular reserve and progressive global cognitive decline in patients with ACS vs those with preserved ipsilateral cerebrovascular reserve (P <.05).

Limitations include the small number and size of the studies, which did not allow a quantitative analysis to be performed. Also, significant heterogeneity occurred regarding the neuropsychologic tests used, and most studies did not include a standard protocol for baseline or follow-up neuroimaging evaluation. Furthermore, most of the participants were men, and most studies were cross-sectional.

“This review provides support for the use of comprehensive neurocognitive assessments and CVR [cerebrovascular reserve] assessment, in addition to longitudinal ultrasound evaluations of carotid plaque progression and/or phenotype, to facilitate risk stratification of patients with ACS,” wrote the researchers. “Clinicians may be prompted to consider cognitive impairment as a critical factor in risk stratification of ACS patients for consideration of carotid interventions.”

Disclosure: One of the study authors declared affiliations with a medical technology company. Please see the original reference for a full list of authors’ disclosures.