Coronary Calcium Scans - May 2008

Did you know…Coronary Calcium Scans are not for everyone?

A coronary calcium scan (also known as a heart scan or EBCT) is a test that can help show whether you have coronary artery disease. Coronary artery disease, the most common form of heart disease and the leading cause of heart attacks, occurs as plaque clogs your arteries. This plaque is made of fat and cholesterol, which over time calcifies. Coronary calcium scans detect the calcifications.

Currently, heart disease risk is measured by evaluating blood pressure, cholesterol levels and tobacco use, along with age and gender to calculate a 10-year risk score. A recent study by the National Heart, Lung, and Blood Institute shows that calcifications can improve the accuracy of predicting heart disease. In this study, over 6,700 Americans from diverse ethnic groups (White, Black, Chinese, Hispanic) were followed for about 4 years. Those who had the highest calcium scores were nearly 10 times more likely to have a heart attack than those with the lowest scores (1).

However, this test may not be for everyone. A coronary calcium scan costs $300 to $600, and most insurance companies do not cover them. People who are non-smokers with healthy cholesterol and blood pressure levels are not likely to benefit from having this test done because it is not known what a high calcification score means in the absence of elevated cholesterol or other evidence of plaque. Also, the test can give falsely positive results (concluding a person is at high risk for heart disease when in fact they are not) leading to unnecessary, invasive, anxiety-producing diagnostic testing such as cardiac catheterization.

Likewise, if a heart scan shows a person’s arteries are free of calcification, it doesn't necessarily mean they don't have heart disease. The plaque that builds up in one’s arteries becomes calcified over a long period of time. It is possible for an individual to have significant non-calcified plaque in their arteries that the scan won't detect. Knowledge of a low calcium score may lead some who are at risk to be falsely reassured and less likely to make needed lifestyle changes.

For someone at high risk (for example, with high cholesterol levels, high blood pressure, and age 65 or older), heart scan results wouldn’t alter a doctor’s appropriately aggressive treatment plan. However, if an individual is in need of motivation to make changes, and can afford to have the test, it might be beneficial. Another recent study showed that people with higher calcium scores - who see the calcifications on their scan -are more motivated to make needed lifestyle changes such as exercise and eat healthy diets (2).

What Does CPC recommend?

Once you know your cholesterol and blood pressure levels, you or your doctor can calculate your 10-year risk using the CPC cardiovascular risk assessment tool at www.health-e-solutions.org. The American Heart Association states that coronary calcium scans may be helpful in individuals who are at moderate risk for a heart attack (a 10 to 20 percent chance of having a heart attack within the next 10 years) to help guide treatment. Finally, if an individual needs motivation to make lifestyle changes, a scan may help that person “see” the impact of unhealthy arteries. Coronary calcium scans are an interesting technique for predicting heart attacks, but it is best to talk first to your doctor to see if it is right for you.

The research cited above was published in: 1. New England Journal of Medicine, March 27, 2008. 2. American Journal of Cardiology, April 1, 2008