DEAR DR. ROACH: You mentioned checking a calcium score to help determine risk of having a heart attack. Please explain what that is. Thank you.
A: A coronary artery calcium score is a special kind of CT scan that looks for the presence of calcium in the arteries providing blood to heart muscle. Blockages in the arteries are usually calcified, and the scan can calculate the total amount of calcium found in the walls of the blood vessels. The higher the calcium score, the more likely a person is to have blockages in the arteries. However, the test isn't perfect. A person can have calcium without having any blockages, and a person may also have a cholesterol buildup that blocks flow without having calcium. It remains a useful test in certain situations.
I most often use the calcium score when I am not sure whether my patient would benefit from medication therapy to reduce their risk of a heart attack. This comes after a person has made the best changes they can to their lifestyle, especially through diet and exercise, and when they do not otherwise choose to take medication. If the calcium score is zero, then treatment (such as a statin drug) may be safely deferred for five years. The risk of a heart attack in that time is very low.
Exceptions would be if a person is at high risk, such as from diabetes, strong family history or smoking. In people whose heart disease risk puts them on the border of a recommendation for medication treatment, a calcium score above zero would tip the scales.
Calcium scores are not useful in people who are at very low risk, since they are unlikely to change the course of treatment. Patients who did not want to take a statin drug may change their mind once they receive the result of a high calcium score, but if medication treatment is recommended anyway, a calcium score is not necessary.