coronary calcium score

The coronary calcium score is a quick, low-radiation CT scan of the heart that counts the calcium deposited in the walls of the coronary arteries, with no injected dye needed. Calcium accumulates in atherosclerotic plaque as it matures, so calcium in the coronary walls is a fingerprint of the disease process. The scan converts the amount and density of that calcium into a single number — the Agatston score.

That number grades the burden of atherosclerosis. A score of zero means no detectable calcified plaque and signals a very low short-term risk of heart attack; scores rising into the hundreds and thousands mark progressively heavier disease and higher risk. The score is used chiefly to refine risk in people without symptoms who sit in a grey zone of uncertainty — for instance, to decide whether borderline cholesterol warrants a statin. It reclassifies many such people up or down.

An honest limit is that calcium scoring sees only calcified plaque, not the soft, non-calcified plaque that more often ruptures to cause sudden events; a score of zero lowers but does not entirely erase risk, especially in younger smokers. It is a risk-stratification tool for prevention, not a test for someone with active chest pain, where it cannot show whether an artery is critically narrowed.