Carotid plaque as a predictor of dementia in older adults: The Three-City Study

Background: The contribution of carotid atherosclerosis to incident dementia remains unclear. We examined the association between carotid plaques (CP) and common carotid intima media thickness (CCA-IMT) with incident dementia and its subtypes, and their added value for dementia risk prediction. Methods: At baseline, 6025 dementia-free subjects aged 65-86 years underwent bilateral carotid ultrasonography measures of CP and plaque-free CCA-IMT. Subjects were followed-up over 7 years for the detection of dementia. Results: After a mean 5.4 years of follow-up, 421 subjects developed dementia including 272 Alzheimer's disease and 83 vascular/mixed dementia (VaD). Only CP were independently related to VaD (HR >= 2 (sites with plaques) = 1.92; 95% confidence interval or CI = 1.13-3.22) and improved VaD risk prediction (continuous Net Reclassification Index = 30.1%; 95%CI = 8.4-51.7) beyond known dementia risk factors. Accounting for stroke or competing risk by death marginally modified the results. Conclusion: In older adults, CP are independent predictors of incident VaD and may improve VaD risk prediction. (C) 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.