eGFR and deep white matter hyperintensity as predictors of cognitive decline long after carotid endarterectomy

Chronic kidney disease and white matter hyperintensity (WMH) are associated with cognitive decline. The aim of this study was to assess the correlations between estimated glomerular filtration rate (eGFR) or WMH and cognitive function in patients who have undergone carotid endarterectomy (CEA). Cognitive functions were investigated using the Neurobehavioral Cognitive Status Examination (Cognistat) in 83 patients who had undergone CEA. The eGFR at 5 years prior to examination was significantly associated with severe cognitive impairment (odds ratio, 0.89 per 1-mL/min/1.73 m² increase, 95% confidence interval 0.82-0.97, p = 0.0004). Receiver operating characteristic analysis revealed that a cutoff eGFR of 46.8 mL/min/1.73 m² at 5 years prior to examination offered the most reliable predictor of severe cognitive impairment (sensitivity 88.9%, specificity 76.5%, area under the curve 0.848). The eGFR at 5 years prior to examination showed a significant linear association with total Cognistat score (r² = 0.11035, p = 0.0032) compared to eGFR at 3 years prior to examination (r² = 0.06455, p = 0.0230) or at examination (r² = 0.0210, p = 0.0210). Spearman's correlation coefficient revealed that orientation, comprehension, repetition, construction, memory, and similarity correlated with eGFR at 5 years prior to examination. Conversely, Fazekas grade for deep WMH at examination was associated with total Cognistat score (p = 0.0016), unlike that at 3 years (p = 0.0100) or 5 years prior to examination (p = 0.0172). While eGFR correlates with future cognitive function, deep WMH associates with present cognitive function in patients who have undergone CEA.