Coronary Artery Calcium Versus Intima-Media Thickness as a Measure of Cardiovascular Disease Among Asymptomatic Adults (from The Rancho Bernardo Study)

Detection and quantification of subclinical coronary heart disease by noninvasive imaging techniques offers the potential for earlier diagnosis with targeted prevention and therapy. This study, designed to determine the extent to which carotid artery intima-media thickness (IMT) predicts coronary artery calcium (CAC) in asymptomatic older adults, included 141 men and 137 women ≥55 years of age with no previous coronary heart disease who had B-mode ultrasound of the common and/or internal carotid arteries in 1997 to 1999 to measure IMT and electron beam computed tomographic scanning in 2001 to 2002 to measure CAC score. Overall, 29% of participants had a severe plaque burden (CAC score >400); 50% of these had a CAC score >800. IMT of the common and internal carotid arteries was significantly associated with the CAC score measured an average of 3 years later. The ability to correctly identify subjects with a severe CAC score (sensitivity) was 50% to 60% for an IMT of the internal or common carotid artery >80th percentile (internal carotid IMT ≥1.9 mm and common carotid IMT ≥1.04 mm). Specificity, the ability to correctly identify those who did not have a severe CAC score (≥400), was ∼75%. In conclusion, IMT of the carotid arteries predicted the severity of CAC burden an average of 3 years later in community-dwelling asymptomatic older adults.