Abstract WMP16: Multi-Marker Cerebral Small Vessel Disease Score and Risk of Incident Dementia in the Framingham Heart Study

Abstract

Background: Individual magnetic resonance imaging (MRI) markers of cerebral small vessel disease (CSVD) are associated with impaired cognition and dementia but may not reflect the overall burden of CSVD. It is unclear whether these markers provide additional value in evaluating the risk of dementia beyond assessments based solely on clinical risk factors. Thus, we aimed to determine whether the association of additive burden of multiple CSVD markers was independent of vascular risk factors and the Framingham Stroke Risk Profile (FSRP) and to also compare results with the FSRP. Methods: We included 1,152 Framingham Heart Study (FHS) participants over the age of 55, free of stroke and dementia, from the Original and Offspring cohorts with available MRI and FSRP data. CSVD score was calculated by summing the number of CSVD features detected in the MRI: cerebral microbleeds, cerebral brain infarcts, extensive white matter hyperintensities, severe perivascular spaces, and cortical superficial siderosis. Two Cox proportional hazards regression models were used to relate the multi-marker CSVD score to incident all-cause dementia and Alzheimer’s dementia. The first model adjusted for education, cohort, and clinical risk factors while the second adjusted for education, cohort, and FSRP. Results: Mean age was 70.9 years (SD: 8.7), 527 (46%) were male, and 211 (18%) had score ≥ 2. Over a median follow-up time of 6.4 years (Q1-Q3: 4.6-11.3), participants with score ≥ 2 had elevated risk of all-cause dementia compared to those with no CSVD markers after adjustment for FSRP (HR: 2.32; 95% CI: 1.46-3.69; p<0.001) and vascular risk factors (HR: 1.76; 95% CI: 1.10-2.81; p=0.02). Score ≥ 2 was also significantly associated with AD after adjustment for FSRP (HR: 2.05; 95% CI: 1.19-3.62; p<0.01), but not vascular risk factors (HR: 1.50; 95% CI: 0.87-2.60; p=0.15). In addition, a 5-percent increase in FSRP was independently associated with incident dementia after adjustment for education and FHS cohort (HR: 1.21; 95% CI: 1.13-1.30; p<0.001). Conclusions: Our results support the use of CSVD score as an indicator for dementia risk and it may be as robust as the FSRP. Further studies are necessary to validate the use of CSVD score in quantifying dementia risk.