Since 2001 we have been collecting data on atherosclerosis within the carotid arteries. This non-invasive test yields graded scores for both the degree and type of atheroma.
This data has been correlated with the results of both coronary angiography and CT scanning calcium scoring, as well as routine risk factors.
Results so far show no useful correlation between standard risk factors and the presence of atheroma. There is, however, a highly significant correlation in the co-existence of carotid and coronary artery atheroma (CAD). This result makes carotid Ultrasound the single most powerful non-invasive (and non- X-ray) test predicting the need for further cardiac evaluation in the screening environment.
In the clinical evaluation of chest pain, the presence of carotid atheroma substantially increases the likelihood of CAD. Of those with proven CAD, 98% have significant carotid atheroma.
These results strongly suggest that carotid ultrasound scanning be included as routine in the initial evaluation of patients suspected of having CAD. It is of course unnecessary in the presence of classical angina where angiography is the next essential diagnostic step.