Abstract TP077: Decreasing Carotid Artery Distensibility is Associated with Increasing WMH Volume Over 13 Years

Introduction: Increasing arterial stiffness has been reported to be predictive of future WMH volume. We examined whether the relationship between increasing arterial stiffness as measured by decreasing carotid distensibility was correlated with increasing white matter hyperintensity (WMH) after 13 years. Hypothesis: Decreasing carotid distensibility measured after 13 years is associated with increasing WMH volume. Methods: We studied participants from GeneSTAR longitudinal cohort study using a Philips 3T brain MRI and carotid ultrasound at baseline with follow-up after 13 years to determine WMH, periventricular WMH (PVWMH), and deep WMH (DWMH) volumes that were segmented from FLAIR MRI and normalized for intracranial volume. Distensibility coefficients derived from carotid ultrasound were standardized as z-scores across both timepoints. A linear mixed-effects model was used to assess the interaction between distensibility and timepoint, testing whether the association between carotid distensibility and WMH volume differed between baseline and follow-up, adjusting for age, sex, systolic blood pressure, race, education, and family relatedness. Results: The study included 250 patients who were 60.4% female with a baseline age 49.47 ± 9.71 years and a mean follow-up time of 13.72 years. At follow-up, higher distensibility was related to smaller changes in WMH volumes and lower distensibility was linked to greater WMH volumes (Total WMH β = −0.118, p = 0.033; PVWMH β = −0.117, p = 0.17; DWMH β = −0.199, p = 0.047). Associations between carotid distensibility and WMH volume differed significantly between baseline and follow-up (Total WMH β = −0.244, p = 0.001; PVWMH β = −0.211, p = 0.021; DWMH β = −0.405, p = 0.002). (Figure 1) Conclusions: Decreasing carotid artery distensibility was robustly associated with increasing WMH, DWMH, and PVWMH volumes after 13 years. This suggests that increasing carotid arterial stiffness, possibly reflecting increasing microvascular stiffness, has a strong influence on increasing WMH lesion volumes regardless of location.