Associations of Cardiovascular Risk Factors, Carotid Intima-media Thickness and Left Ventricular Mass with Inter-adventitial Diameters of the Common Carotid Artery: the Multi-Ethnic Study of Atherosclerosis (MESA)

Background: Common carotid artery inter-adventitial diameter (IAD) and intima-media thickness (IMT) are measurable by ultrasound. IAD may be associated with left ventricular mass (LV mass) while IMT is a marker of subclinical atherosclerosis. It is not clear if IAD is associated with LV mass after accounting for IMT and traditional cardiovascular risk factors.

Methods: IAD and IMT were measured on participants of the Multi-Ethnic Study of Atherosclerosis (MESA) IMT progression study. A total of 5641 of the originally enrolled 6814 MESA participants were studied. LV mass was measured by magnetic resonance imaging. Multivariable linear regression was used with IAD as the outcome and adjustment for risk factors, as well as IMT and LV mass.

Results: Traditional cardiovascular risk factors, height, weight and ethnicity were significantly associated with IAD. After adjustment for risk factors, a 1mm difference in IMT was associated with a 1.802mm (95% CI: 1.553, 2.051) higher mean IAD. A 1g difference in LV mass was associated with a 0.006mm (95% CI: 0.005, 0.007) higher mean IAD. After adjusting for cardiovascular risk factors and IMT, a 1g difference in LV mass was associated with a 0.006mm (95% CI: 0.005, 0.008) higher mean IAD for women and 0.004mm (95% CI: 0.003, 0.005) higher IAD for men.

Conclusions: Inter-adventitial diameters are associated with left ventricular mass after adjusting for cardiovascular risk factors and IMT. IAD might serve as a surrogate for left ventricular mass and have predictive value for cardiovascular outcomes.