Abstract 3448: Differences in the Associations between Various Ultrasound-Based Markers of Peripheral Atherosclerosis at Carotid and Femoral Levels and Risk factors in a general Middle-Aged Population
Introduction: Ultrasound detection of sub-clinical atherosclerosis (ATS) is a useful mean to identify subjects at high risk of cardiovascular (CV) events. Most studies have evaluated intima-media thickness (IMT) at the carotid artery level, but plaque-based markers (plaque thickness, plaque area) as well as the femoral artery level have been proposed as valid alternatives. The superiority of one method upon the others has not been demonstrated. The aim of this study is to compare the relationships between five indicators of ATS (IMT, mean / maximal plaque thickness, mean / maximal plaque area) at both carotid and femoral levels and conventional cardiovascular risk factors (CVRF) in a population-based sample of middle-aged adults.
Methods: High resolution B-mode ultrasound was performed in both right and left carotid and femoral arteries on 496 consecutive participants aged 45– 64 randomly selected from the general population. A plaque was defined as a focal IMT thickening ≥ 1.2 mm. CVRF included age, sex, current smoking, systolic blood pressure, LDL-cholesterol, HDL-cholesterol, and diabetes.
Results: All CVRF were associated, independently of age, with each of the ATS markers at femoral level but only LDL-cholesterol and systolic blood pressure were consistently associated with ATS markers at carotid level. The table⇓ shows the adjusted R-squared values in a multivariate model with all CVRF. Variance (adjusted R2) in predicting any of the ATS markers was larger at femoral than carotid levels. At both carotid and femoral levels, the CVRF accounted for more variance in predicting plaque-based markers than IMT.
Conclusion: The stronger association of CVRF with ATS markers at the femoral than carotid levels and with plaque-based markers than with IMT suggest that markers assessed at femoral level and based on plaque morphology might be the most useful tools for assessing cardiovascular risk. These findings need to be confirmed in prospective studies with CV events.