Abstract TP204: Intima-Media Thickness in the Carotid Bifurcation, But Not Cardio-Ankle Vascular Index or Ankle-Brachial Index, is Related to Silent Brain Infarct on Magnetic Resonance Imaging in Healthy, Middle-Aged Japanese Individuals

Abstract

Background: Carotid ultrasonography is currently the principal noninvasive tool for evaluating subclinical atherosclerosis and carotid artery disease. Increased carotid intima-media thickness (IMT) may precede the development of atherosclerotic plaques. Several studies have shown that increased IMT is associated with increased incidence of stroke. Silent brain infarct (SBI) has been proposed as a strong subclinical risk marker for future symptomatic stroke onset. However, the relationship between SBI and elevated IMT in healthy, middle-aged Japanese individuals has not been adequately examined. Methods: We examined 280 Japanese adults (92 women; mean age, 52.9 ± 5 years) with no history of cardiocerebrovascular disease. We assessed all participants’ periventricular hyperintensities, deep subcortical white matter hyperintensities, SBI on magnetic resonance imaging, cardio-ankle vascular index (CAVI)/ankle-brachial index (ABI), and various vascular risk factors. In addition, we measured intima-media thickness at the common carotid artery (CCA), carotid bifurcation (CB), and internal carotid artery (ICA). Results: Participants were categorized into two groups according to the presence or absence of SBIs, and we then compared the clinical characteristics of the two groups. Age, hypertension, increased HbA1c level, and decreased estimated glomerular filtration rate were found to be significantly associated with the SBI group. The odds ratio (OR) of the maximum IMT at the CB for the presence of SBI was 4.016 (95% confidence interval [CI], 1.565-10.304), even after adjusting for potential confounding factors. In contrast, the ORs of maximum IMT at the ICA and CCA as well as CAVI and ABI were not significant. Participants with IMTs ≥2 mm at the CB had a higher probability of the presence of SBI (OR, 26.451; 95% CI, 2.404-291.00). Conclusion: The maximum IMT at the CB was significantly correlated with the presence of SBI on MRI, but ABI or CAVI did not show significant correlation. Thus, compared to CAVI or ABI, carotid ultrasonography appears to be a very useful tool for noninvasively detecting SBI. In particular, IMTs ≥2 mm at the CB on carotid ultrasonography may be practical for identifying SBIs among middle-aged Japanese individuals.