Relationship between carotid disease on ultrasound and coronary disease on CT angiography.

OBJECTIVES: The purpose of this study was to assess the relationship between carotid artery disease by ultrasound and coronary artery disease by coronary computed tomography angiography (CTA) and to identify carotid ultrasound parameters predictive of coronary artery disease.

BACKGROUND: Carotid ultrasound and CTA are noninvasive modalities used to image atherosclerosis. Studies examining the relationship between the 2 tests, however, are lacking.

METHODS: We performed carotid ultrasound on predominantly nondiabetic subjects referred for CTA. Carotid intima media thickness (IMT) and plaque were assessed and compared with coronary artery calcification and the number of coronary arteries with any evidence of atherosclerosis on CTA.

RESULTS: A total of 150 subjects underwent both CTA and carotid ultrasound on the same day. Carotid plaque was present in 71.3% (n = 107), whereas the presence of at least 1 coronary artery with disease on CTA was present in 57.1% (n = 84). Carotid plaque was present in 47.6% (30 of 63) of subjects with a calcium score of 0 and 88.5% (77 of 87) of subjects with a calcium score >0 (p = 0.0001). Similarly carotid plaque was present in 52.4% (33 of 63) of subjects with no CTA evidence of atherosclerosis versus 85.7% (72 of 84) of subjects with any CTA evidence of atherosclerosis (p < 0.0001). Carotid plaque, IMT ≥ 1.5 mm, or averaged mean IMT >0.75 mm were associated with a calcium score >0 (odds ratio: 5.4, p < 0.0001, 2.7, p < 0.001; 2.9, p = 0.011, respectively) and disease in at least 1 vessel on CTA (odds ratio: 2.8, p = 0.03, 2.19, p = 0.073; 2.22, p = 0.058, respectively) independent of age and sex.

CONCLUSIONS: Carotid plaque and increased carotid IMT are associated with the presence and severity of coronary calcification and disease on CTA in ambulatory subjects.