Asymptomatic cerebral ischemia after carotid artery stenting as a predictor of cognitive impairment

Objective: The study aimed to compare cognitive functions in patients with asymptomatic cerebral ischemic lesions and without cerebral ischemic lesions after carotid artery stenting (CAS). Methods: A prospective cohort study was based on a subanalysis of 100 patients from the SIBERIA study database who underwent CAS. Patients with a history of stroke or contralateral occlusion of the internal carotid artery, with the development of a vascular event or death during 12 months of follow-up, and individuals with lost contacts were excluded from the analysis. Patients completed the MMSE (Mini-Mental State Examination) test before and after CAS stenting at 6 and 12 months. All three tests were completed by 39 patients with asymptomatic cerebral ischemic lesions and 36 patients without cerebral ischemic lesions on diffusion-weighted magnetic resonance imaging (MRI) of the brain in the early postoperative period after CAS. Pseudo-randomization was performed in a 1:1 ratio using the propensity score matching method, after which 30 patients were included in each group. The primary endpoint was the development of predementia/dementia. Results: In the group patients with asymptomatic cerebral ischemic lesions, both a significantly lower median score on the MMSE test (26 [25; 28] versus 28 [28; 29], p < 0.001) and a greater number of patients with dementia/predementia (18 (60%) versus 7 (23.3%), p = 0.008) were found compared with the control group in 12 months after CAS. Asymptomatic cerebral ischemic lesions increased the risk of developing predementia/dementia within 12 months after CAS (RR 2.57 [1.07; 6.15], p = 0.02). The total volume of asymptomatic cerebral ischemic lesions ≥ 78 mm3 predicted a decline in cognitive functions. Conclusion: Asymptomatic cerebral ischemic lesions after CAS significantly increased the risk of developing cognitive impairment during 12 months after procedure.