BOSTON – Asymptomatic carotid stenosis is associated with cognitive impairment when compared to patients with similar risk factors but no stenosis, said Dr. Brajesh K. Lal, of the University of Maryland, Baltimore.
Dr. Lal presented results from the Asymptomatic Carotid Stenosis and Cognitive Function (ACCOF) study. "The key finding is that we've identified for the first time unequivocally that an asymptomatic carotid artery plaque in a patient that has never suffered a stroke before can result in cognitive impairment," Dr. Lal said at the Vascular Annual Meeting.
Vascular comorbidities, such as diabetes, hypertension, coronary disease, and hyperlipidemia, are well known to cause vascular cognitive impairment (VCI), and this new research indicates that ACS should be added to that list, according to Dr. Lal and his colleagues.
They assessed 129 patients, 69 with greater than or equal to 50% ACS and 60 controls with vascular co-morbidities without ACS. An overall index of cognitive function and five domain-specific scores were computed. Breath-holding index (BHI), an estimate of cerebrovascular reserve, was measured using transcranial Doppler. Patients were assigned to high vs. low BHI groups using a cut-off score of 0.69. They assessed differences among stenosis vs. control patients and stenosis patients with low vs. high BHIs.
The stenosis and control groups did not differ with respect to vascular risk factors, IQ, educational attainment, and depressive symptoms. The stenosis group performed worse on the overall composite cognitive score and the domain-specific scores for processing speed and learning/memory, all significant differences. Within the stenosis group, those with low BHI performed significantly worse on learning, and trended lower on processing speed and overall composite score.
"The ACCOF study results showed that asymptomatic carotid stenosis is associated with cognitive impairment when compared to patients with similar risk factors but no stenosis. The deficit is driven primarily by reduced processing speed and learning/memory, and is mild to moderate in severity. A likely mechanism for this impairment is reduced cerebrovascular reserve," said Dr. Lal. "These findings have the potential to impact decision making in the management of patients with ACS."