Background: Previous studies have demonstrated that elevated pre-operative monocyte count is an independent predictor of acute neurocognitive decline following carotid endarterectomy (CEA). Monocyte chemoattractant protein-1 (MCP-1), secreted by human endothelial and monocyte-like cells, is a potent mediator of inflammation and mononuclear cell trafficking. This study examines the relationship between peri-operative serum MCP-1 elevation and post-operative neurocognitive injury following CEA.
Methods: Fifty-two patients undergoing CEA and 67 lumbar laminectomy (LL) controls were administered a battery of five neuropsychological tests pre-operatively and on post-operative day 1 (POD 1). Change in individual test scores from baseline to POD 1 were converted into Z-score and used to develop a point system quantifying the degree of neurocognitive dysfunction relative to change within the LL group. Neurocognitive injury following CEA was defined as a score greater than 2 standard deviations above mean total deficit scores of LL controls. Serum MCP-1 levels were measured pre-operatively and on POD 1 by enzyme-linked immunosorbent assay.
Findings: Mean percent MCP-1 elevation was higher for the 13 injured CEA patients (147.7 +/- 32.4%) in our cohort compared to 39 age- and sex-matched uninjured CEA patients (76.0 +/- 16.5%). In unconditional multivariate logistic regression analysis, percent elevation in serum MCP-1 level was associated with neurocognitive injury one day after CEA (OR = 2.19, 95% CI = 1.13-4.26, P = 0.021, for a 100% elevation from pre-operative levels).
Conclusions: Peri-operative elevations in serum MCP-1 levels correlate with acute neurocognitive dysfunction following CEA. These data implicate an inflammatory mechanism in the pathogenesis of Ischaemic neurocognitive decline.