A high normal ankle-brachial index combined with a high pulse wave velocity is associated with cerebral microbleeds

Objectives: Arterial stiffness is associated with the pathogenesis of cerebral microbleeds (CMBs). The ankle-brachial index (ABI) is used to predict arterial stiffness. We hypothesized that the increase in ABI with age occurs as a result of increasing arterial stiffness and wave reflection, and is thus associated with target organ damage. The aim of this study was to investigate the relationship between ABI, brachial-ankle pulse wave velocity (baPWV), and CMBs. Methods: We recruited 990 cardiovascular disease-free and stroke-free participants [median age 53 (24-86) years, 531 were woman] who underwent brain MRI, ABI, and baPWV at a health checkup. Results: The prevalence of CMBs was 4%. Both ABI (1.14 vs. 1.10) and baPWV (17.29 vs. 14.68 m/s) were higher in participants with CMBs than those without. Cutoff values of ABI and baPWV for the presence of CMBs were 1.12 and 16.07 m/s, respectively. Multivariate logistic regression analysis showed that ABI at least 1.12 [odds ratio (OR) 2.57, 95% confidence interval (CI) 1.30-5.37, P<0.05] and baPWV at least 16.07 m/s (OR 2.08, 95% CI 1.02-4.38, P<0.05) were independently associated with CMBs. Moreover, the combination of ABI at least 1.12 and baPWV at least 16.07 m/s was strongly associated with CMBs (OR 5.26, 95% CI 1.93-16.92, P<0.05). Conclusion: A high normal ABI, combined with a high baPWV, was strongly associated with CMBs in a screened Japanese cohort, suggesting a novel use for ABI as a predictor for target organ damage.