Carotid Endarterectomy Is Associated With Postoperative Neurocognitive Improvement in Both Symptomatic and Asymptomatic Patients

Abstract

While stroke after carotid endarterectomy (CEA) is rare, magnetic resonance imaging shows that “silent” microinfarctions after surgery are much more common. These microinfarcts have been correlated with neurocognitive decline. However, there is also evidence that revascularization may improve overall cognition due to improved cerebral blood flow and elimination of embolic source. As part of a trial of remote ischemic preconditioning as a possible neuroprotective mechanism during CEA, we examined the overall impact of carotid revascularization on cognitive function. This is an interim noncomparative analysis of the cohort enrolled in an institutional randomized trial for the role of remote ischemic preconditioning for CEA (RIP-CEA, NCT02808754). All patients underwent baseline neurocognitive testing using the Montreal-Cognitive Assessment (MoCA) and National Institutes of Health Toolbox (Flanker Inhibitory Control and Attention Test, the Dimensional Change Card Sort Test, and the Pattern Comparison Processing Speed Test). These tests specifically assess executive function and processing speed. MoCA was also conducted on postoperative day 1 in the hospital. The full neurocognitive testing battery was conducted again at the 1-month follow-up in the office. Score changes from baseline were examined at the follow-up time points. Eighty patients with a mean age of 71.3 ± 7.1 years (65% male, and 30% symptomatic) were enrolled. The average baseline MoCA score was 24.7 ± 2.8 and this was similar between symptomatic and asymptomatic patients (P = .6). Forty-seven percent of patients met criteria for cognitive decline (MoCA < 26) at baseline. While MoCA scores remained unchanged immediately postoperatively, patients experienced significant improvements in MoCA scores by 1 month after CEA (average MoCA score of 26.3 and only 26% qualifying as cognitive decline; P < .001). Similarly, patients experienced significant improvements in executive function (26.4 ± 4.7 months before CEA vs 28.3 ± 2.3 1 months after CEA; P < .001) and processing speed at 1 month after CEA (31.8 ± 9.2 months before CEA vs 35.8 ± 8.4 1 months after CEA; P < .001) as assessed by the National Institutes of Health toolbox. There was no difference in the number or degree of cognitive improvement between symptomatic and asymptomatic patients. Statin use was a significant predictor of improvement on MoCA score at 1 month (OR, 3.9; P < .05). Carotid revascularization with CEA is associated with significant improvements in neurocognitive function by one month post operatively across multiple domains. Statin use may be further protective. Longer term follow-up is needed to see the magnitude and durability of these cognitive improvements. Neurocognitive improvement following CEA may justify reconsideration of the role of carotid revascularization in asymptomatic patients.