BACKGROUND:

This study meshed with a longitudinal case-control study, HL-35333, Carotid Atherosclerosis Follow-Up Study. HL-35333 comprised 280 individuals older than 45 equally divided between men and women, half with and half without CAD evaluated for risk factors at baseline and with completed follow-up with yearly B-mode for three years. The Carotid Atherosclerosis Follow-Up Study quantified the interassociations of angiographically defined coronary artery disease and CAD risk factors with progression. The NIH funded a continuation of this effort to review existing ultrasound tapes from this study in order to additionally evaluate the associations of all these factors with extracranial carotid arterial dimensions (ECAD: interadventitial and lumen diameters) and change in ECAD over time.

DESIGN NARRATIVE:

The study assessed brachial artery reactivity among 100 CAD subjects and 100 controls who had been previously enrolled in a study of the relationship between extracranial intima media thickness (ECIMT) as assessed by B mode ultrasonographic measurements and CAD status. Most subjects had three consecutive B mode measurements at 12 month intervals. These subjects had brachial artery reactivity measurements according to a standardized protocol. Linear regression analysis was used to relate brachial artery reactivity to CAD status, gender and risk factors as predictors. Interaction effects were also assessed between CAD status and other risk factors and also between gender and other risk factors. Similar analyses were performed to relate percent dilation to ECIMT measurements.