What is a CAC (calcium score) CT scan and should I get one?

A coronary artery calcium (CAC) score CT is a non-invasive low-radiation scan (equivalent to about 20 chest X-rays) that quantifies calcified plaque in the coronary arteries, producing a score (Agatston units) that directly measures the burden of atherosclerotic disease already present, with a score of 0 indicating extremely low cardiovascular event risk for the next 10–15 years, and a score above 100 indicating substantial plaque burden warranting aggressive cardiovascular risk management (Agatston et al., JACC, 199090282-T)).

The CAC score is the single most informative cardiovascular risk reclassification tool available in 2026, it tells you what is actually in your arteries, not what a population-level risk calculator predicts might be there based on your risk factors. For men aged 40–65 who are in intermediate cardiovascular risk (10-year risk of 7.5–20% by pooled cohort equation), a CAC score of 0 can reclassify them to low risk and avoid statin therapy; a score above 100 can reclassify them to high risk and confirm the need for therapy.

Honesty Scale: Solid (1) for CAC as the most informative cardiovascular risk reclassification tool in asymptomatic men.

What to do: Discuss CAC scoring with your cardiologist if you are 40–65 with any cardiovascular risk factors (family history, elevated ApoB, hypertension, smoking history, diabetes). The scan takes 11 minutes, typically costs $100–$200, and is not usually covered by insurance for primary prevention purposes, but provides more specific information than a decade of annual lipid panels.

For the full picture, read The ApoB/Lp(a)/Lipids Deep Dive