A study reported in the Journal of the American College of Cardiology demonstrated the value of carotid IMT testing for early detection of coronary artery disease. The article showed that there is a high correlation between carotid plaque and atherosclerosis and coronary artery disease (CAD) as detected through coronary computed tomography angiography (CTA).

Tests such as HeartSmart IMTplus can detect cardiovascular disease at its earliest stages alerting physicians and patients to the potential presence of CAD. Unlike CTA, carotid IMT testing can be conveniently done in the primary care physician’s office with no radiation exposure to the patient.

Among other things, the study showed a 78.5% correlation between patients with carotid plaque and CAD in at least one coronary artery and that carotid plaque was present in 88.5% of patients with calcium scores greater than zero. In addition, carotid IMT testing showed carotid plaque in 47.6% of patients suggesting that early detection of carotid atherosclerosis and plaque predict future coronary artery disease.

A basic overview of the study includes:

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.

The complete study can be found online at:
http://imaging.onlinejacc.org/article.aspx?articleid=1768643