What Your Coronary Artery Calcium (CAC) Score Means
A CAC scan measures calcified plaque in your heart's arteries — a direct look at disease, not just risk. Here's what a score of 0, 100, or 400+ means.
Manifold Health Clinical Team
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Your coronary artery calcium (CAC) score is a direct measurement of the calcified plaque already in your heart's arteries — which makes it one of the few tests that shows actual disease rather than just estimated risk.
A CAC scan is a quick, low-dose CT of the heart. It counts calcified plaque and returns a single number that strongly predicts your risk of a future cardiac event. This is educational content, not medical advice.
The short version
CAC measures calcified plaque already present — disease, not just risk.
0 = no detectable calcified plaque and low near-term risk; 1–100 = mild; 101–400 = moderate; above 400 = extensive, high risk.
A score of 0 is powerfully reassuring; a high score is a strong reason to act.
It's especially useful when your risk is uncertain and you're deciding about prevention.
What the score means
0 — no calcified plaque detected; 10-year event risk is low (often ~1–2%). 1–100 — a small amount of plaque, low-to-moderate risk. 101–400 — a moderate amount, intermediate-to-high risk. Above 400 — extensive plaque and high risk. Scores are also compared to others your age and sex (percentiles). The higher the number, the greater the likelihood of a future heart attack or stroke.
Why it's so useful
Many people sit in an "intermediate risk" gray zone where it's unclear how aggressively to prevent. A CAC score cuts through that: a 0 can safely reassure, while a high score reframes prevention as urgent. It complements bloodwork — markers like ApoB tell you what's driving risk, while CAC shows what's already happened.
What to do with the result
A higher CAC score generally prompts more intensive risk-factor control — cholesterol, blood pressure, blood sugar, and lifestyle — guided by a clinician. A score of 0 doesn't mean you can ignore risk factors, but it often supports a more measured approach. Note that CAC measures calcified plaque, so very early soft plaque may not register.
Which provider and what to ask
Primary care, cardiology, and preventive clinicians order and interpret this. Ask: Would a CAC scan clarify my risk? Given my score, how aggressively should we prevent? What's my percentile for my age?
Frequently asked questions
Is a CAC scan safe?
It uses a low dose of radiation and takes only minutes; discuss timing with your clinician.
What if my score is 0?
It's reassuring and predicts low near-term risk, though risk factors still matter over time.
Does insurance cover it?
Coverage varies; many people pay a modest out-of-pocket cost.
Key takeaways
CAC shows calcified plaque you already have — disease, not just risk.
0 low, 1–100 mild, 101–400 moderate, 400+ high.
Especially valuable for intermediate-risk decisions.
Clarify your heart risk
Sidewalk can help you decide whether a CAC scan fits and find a provider who uses it well. Complete a free AI health assessment or find a provider.
This article is for educational purposes only and is not a substitute for professional medical advice.
