Carotid Ultrasound Maximum Plaque Height–A Sensitive Imaging Biomarker for the Assessment of Significant Coronary Artery Disease

OBJECTIVES: We investigated the use of carotid intima-media thickness and carotid plaque in predicting significant angiographic coronary stenosis. METHODS: Three hundred eighteen consecutive outpatients underwent angiography and carotid ultrasound on the same day. The extent of coronary stenosis was determined using an established scoring system. Mean far distal carotid intima-media thickness of the common carotid artery, maximum plaque height, and total plaque area in the bulbs were measured by ultrasound. Cutoff values were identified using a receiver operating characteristic curve for predicting and ruling out coronary artery disease. RESULTS: The mean ± SD carotid intima-media thickness (≥50% stenosis = 0.91 ± 0.23 mm, <50% stenosis = 0.82 ± 0.18 mm), maximum plaque height (≥50% stenosis = 2.64 ± 0.85 mm, <50% stenosis = 1.72 ± 1.04 mm), and total plaque area (≥50% stenosis = 39.1 ± 27.7 mm(2) , <50% stenosis = 22.2 ± 23.4 mm(2) ) were significantly higher in patients with coronary artery disease (P ≤ 0.001 for all three comparisons). Increased CIMT, plaque height, and area correlated with increased number of affected vessels. Plaque height had the best negative likelihood ratio for ruling out disease (0.15). The optimal threshold values for predicting coronary disease were 0.82 mm for carotid intima-media thickness, 1.54 mm for plaque height, and 25.6 mm(2) for total plaque area. CONCLUSION: Increased carotid intima-media thickness and plaque measurements are indicative of the presence of epicardial coronary stenosis. Plaque burden is a more sensitive imaging biomarker for ruling out significant coronary artery disease, including in younger individuals.