What’s Your Coronary Artery Calcium Score?

The use of computerized tomography, or CT, allows the amount of calcium in coronary arteries to be estimated. This can give an idea of the likely risk of a cardiovascular event, such as a heart attack or MI. Coronary artery calcium (CAC) scoring is now being done more widely, and is proving to be a “valuable and appropriate approach in a selected patient population”, according to a recent statement from the American College of Cardiology.

CAC scanning is better than other available methods for determining risk, especially in people without symptoms but who have a 10% to 20% 10-year risk of a coronary event (as determined by the Framingham method). It may show if, in fact, the risk level should be raised for a particular patient, so that appropriate measures can be taken in good time. But it is of no value in people with a less than 10% 10-year risk; and people with a higher than 20% 10-year risk should already be having intensive risk-reducing therapies.

People aged 65 to 75 stand to benefit most from CAC scanning if they’ve never had a calcium scan or heart symptoms. Its accuracy is not limited by concurrent medication, the patient’s ability to exercise, baseline heart-wall motion, or electrocardiogram abnormalities. A score between 1 and 99 is a good reason to have a repeat scan in a year, and probably annually after that. Between 100 and 399 indicates the subject is in the 10% to 20% 10-year risk level. A score over 400 would mean that the individual is a candidate for intensive preventive treatment.