• Cognitive Disorders Clinical Trials
• Coronary Artery Disease
• Dementias

• Cognitive Disorders
• Neurology Clinical Trials
• Coronary Artery Disease
• Neurology
• Dementias

Moira C. Dux, PhD, University of Maryland School of Medicine and Baltimore VA Medical Center, Baltimore, Maryland, USA, presented results from a cross-sectional study that demonstrated significantly worse cognition in patients with asymptomatic carotid stenosis compared with patients with vascular risk factors but no stenosis. The difference was driven primarily by poor motor and processing speed and learning and memory in patients with asymptomatic carotid disease, with deficits ranging from mild to moderate.

Several published studies have identified evidence of cognitive impairment in patients with asymptomatic carotid disease. However, methodologic issues, such as the use of healthy controls, the use of differing cognitive testing, and inadequate standardization of scores, have raised questions regarding the validity of these findings.

The Asymptomatic Carotid Stenosis: Cognitive Function and Plaque Correlates study (ClinicalTrials.gov identifier NCTO1353196) was designed to provide a comprehensive assessment of neuropsychological function in patients with asymptomatic carotid stenosis compared with patients with similar vascular risk factors but no evidence of carotid stenosis. A total of 67 consecutive patients with ≥50% carotid stenosis and no prior transient ischemic attack or stroke as well as 60 control patients with risk factors for vascular disease but no evidence of carotid stenosis underwent comprehensive cognitive testing (Table 1). The presence and degree of stenosis were confirmed by duplex ultrasonography, while asymptomatic status was determined by neurologic and National Institutes of Health Stroke Scale testing.

Test scores were adjusted for age, sex, education, and race using standardized normative data. An overall index of cognitive function and 5 domain-specific composite scores were calculated. Independent-sample t tests were used to compare groups, and Cohen's d was calculated to determine effect sizes.

The proportion of vascular risk factors was similar in both groups (Table 2).

Patients with asymptomatic carotid stenosis performed worse on the overall neurocognitive composite score (t=2.8, p<0.01, d=0.52), the motor and processing speed domain score (t=3.5, p<0.01, d=0.69), and the learning and memory domain score (t=2.6, p<0.05, d=0.48) compared with the control group. There was a trend toward worse performance for executive function, attention, and working memory (d=0.35 and d=0.26, respectively). The groups did not differ on the language domain; both performed in the normal range. Full results are illustrated in Figure 1.

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Figure 1.

Outcomes for Neurocognitive Measures

*p≤0.15;**p≤0.05.Reproduced with permission from M. C. Dux, PhD.

These findings showed that patients with asymptomatic carotid stenosis do have increased evidence of neurocognitive impairment. This study did not explore why patients with >50% carotid stenosis have an increase in cognitive dysfunction compared with matched controls (eg, increased silent strokes on magnetic resonance imaging). Moving forward, further studies are needed to explore these issues, as well as to determine whether modified diagnostic approaches (eg, increased screening for stenosis) and new treatment approaches (eg, cognitive rehabilitation, aggressive medical management, revascularization) or targets (eg, cognitive symptoms) can improve outcomes in patients with asymptomatic carotid stenosis.

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