Small Vessel Disease Burden Predicts Incident Dementia and Poor Functional Outcome in Independent Outpatients

Background: Total small vessel disease (SVD) score is used to measure the burden of SVD. Objective: This study aimed to clarify the predictive value of total SVD score for incident dementia and functional outcomes in independent outpatients with vascular risk factors. Methods: We derived data from a Japanese cohort in which patients underwent magnetic resonance imaging and cognitive examinations. They were followed up until March 2023. The primary outcomes was dementia. Secondary outcome was functional outcomes. We measured a modified Rankin scale (mRS) score at the last visit and defined poor functional outcomes as mRS score ≥3. Results: After excluding those with a mRS score ≥2, Mini-Mental State Examination score in Japanese version < 24, and missing T2* images, 692 patients were included. During a median follow-up period of 4.6 years, dementia occurred in 31 patients. In multivariate analysis, the score 4 group showed a significantly higher risk of incident dementia than the score 0–3 groups (adjusted hazard ratio, 6.25; 95% CI, 1.83–21.40, p = 0.003). The total SVD score was also independently related to poor functional outcome. Conclusions: The total SVD score of 4, and ≥1 could predict dementia and poor functional outcomes, respectively. Our results suggest intensive management of patients with SVD to prevent dementia and to maintain independent activities of daily living.