In other words, does a coronary calcium score and a Carotid Intima Media Thickness (CIMT) scan give the same information?
Although they both detect atherosclerosis, they do so at different stages of disease. Costs for both tests in our community are comparable, and the CIMT scan is far more portable.
In addition, I have 2 concerns with coronary calcium score. First, it is not useful for measuring the effects of treatment. Without going into great detail, it does not improve when artery health improves because calcium deposition occurs late in the development of plaque and will not decrease with treatment. It represents old scar.
The second concern is that early, new, soft, non-calcified, dangerous unstable plaque is not detected because it has not yet become calcified. A test that misses the most dangerous form of the disease is not as useful as one would hope.
The Carotid Intima Media Thickness Scan detects plaque at all stages, including the more dangerous non-calcified plaque mentioned above.
Granted, it is a surrogate sample measurement used to measure atherosclerosis generally. It does not look directly at the arteries supplying the heart.
But if you have plaque in your carotid arteries, you should assume you have plaque elsewhere, including the coronaries. Treatment that improves the carotid artery health improves arterial health generally.
And improvement (or progression) can be measured and documented. The effects of treatment to reduce atherosclerotic burden can be seen. If improvement isn’t seen as expected, treatment can be adjusted.
Coronary calcium score is not useful for serial measurement of atherosclerosis development.
At the Center for Prevention of Heart Attack & Stroke, we do CIMT first. If no disease is detected in an individual where it is expected due to a high risk profile, coronary calcium score is a consideration to be more sure the coronaries are not diseased before the carotids.
I hope you found this answer helpful!