Calcium Score

A coronary artery calcium score is a short, non-invasive CT scan that measures how much calcified plaque has built up in the walls of the heart's arteries. Calcium deposits are part of established atherosclerosis, so the amount visible is a direct marker of how much disease is present — information that cholesterol numbers and risk calculators can only estimate.

No contrast dye is used, no IV is needed, and the scan itself takes only a few seconds of breath-holding.

The result is a single number, the Agatston score:

• 0 — no detectable calcified plaque, which carries a low risk of a heart attack over the following several years
• 1–99 — mild plaque
• 100–399 — moderate plaque
• 400 or higher — extensive plaque and a substantially higher risk

The score is also reported as a percentile against others of your age and sex, which is often the more meaningful figure — a modest score in a younger person can be more concerning than the same number decades later.

Calcium scoring is aimed at adults with no symptoms who fall in an intermediate risk category, where the decision to start a cholesterol-lowering medication is genuinely uncertain. A score of zero may support holding off; a high score often reclassifies someone into a higher risk group and argues for treating more aggressively.

It is generally not the right test if you are already having symptoms such as chest pain — a stress test or a CT angiogram answers that question better — or if you already have known coronary disease or are already on statin therapy for it, since the result would not change the plan.

Plan on about 10 to 15 minutes in the department. You lie on the scanner table, EKG sensors are placed so the images can be timed to your heartbeat, and you hold your breath for a few seconds while the scan runs. There is no preparation beyond avoiding caffeine and nicotine beforehand if you are asked to, and you can drive yourself home and return to normal activity immediately.

The radiation dose is low — in the range of a screening mammogram.

The scan sees calcified plaque only. Younger, softer plaque that has not yet calcified does not register, so a score of zero is reassuring but is not a guarantee that the arteries are free of disease — particularly in adults under about 45. A calcium score also does not tell you whether a given artery is narrowed enough to limit blood flow; that requires a different test.

Calcium scoring is often treated as a screening test and may not be covered by insurance. Practices commonly offer it at a modest self-pay price, and it is worth asking about the cost when scheduling.