BiomarkerInflammation & Vascular

Coronary Artery Calcium

Direct imaging of coronary plaque burden

Last reviewed: July 2026
Version: 1.0
Review cadence: Annually

Overview

The coronary artery calcium (CAC) score is a quick, low-radiation CT scan that measures calcified plaque in the heart's arteries. It is a direct look at whether atherosclerosis is actually present, expressed as an Agatston score.

Why it matters

CAC is one of the most powerful tools for refining cardiovascular risk, especially when a decision (like starting a statin) is uncertain. A score of zero indicates very low near-term risk (the 'power of zero'), while a high score reveals established disease that argues for aggressive prevention.

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Typical Journey

How this usually unfolds

Measure it
Understand your result
See what raises and lowers it
Apply evidence-based interventions
Recheck on your review cadence

An orientation to how this topic is typically approached — not medical advice.

Optimal Range

Where the evidence points

CAC 0 = no detectable calcified plaque (very low near-term risk); 1–99 mild; 100–399 moderate; ≥ 400 high plaque burden.

CAC detects calcified plaque; early soft (non-calcified) plaque can exist with a score of 0, and CAC is generally not repeated frequently.

Clinical interpretation

CAC reclassifies risk: a zero score can safely defer statin therapy in many intermediate-risk people, while a high score reclassifies upward and supports intensive risk-factor treatment. It is a decision aid layered on top of ApoB/LDL and blood pressure, not a replacement for them.

What raises and lowers it

Raises it

Age and accumulated cardiovascular risk
Elevated ApoB/LDL over time
Hypertension, diabetes, smoking
Elevated lipoprotein(a)
Genetics

Lowers it

CAC generally does not decrease (calcified plaque persists)
Risk-factor control slows progression rather than reversing the score

Related Evidence

How this connects across BioSignal

Related pharmaceuticals

Statins (CAC often guides the decision to start)

Related lifestyle interventions

Lower ApoB/LDL
Blood pressure control
Not smoking

Diagnostics

Non-contrast cardiac CT (Agatston score)
Low radiation; no contrast needed

Frequently asked questions

What does a calcium score of zero mean?

It means no calcified plaque was detected, which corresponds to very low near-term cardiovascular risk — often enough to safely defer a statin in intermediate-risk people. It's reassuring, though not a permanent guarantee.

If my score is high, can I lower it?

Generally no — calcified plaque doesn't disappear. What you can do is aggressively control the drivers (ApoB/LDL, blood pressure) to slow progression and stabilize plaque, which is exactly what a high score argues for.

Evidence summary

CAC is a validated, guideline-endorsed risk-enhancing tool that improves cardiovascular risk prediction and helps personalize statin decisions, particularly in intermediate-risk adults.

References & sources

2018 ACC/AHA Cholesterol Guideline (CAC as a risk decision aid)
MESA study and CAC risk literature

Sources are named authoritative guidelines and scientific bodies. Biomarker pages present established clinical context; calibrated evidence verdicts on specific interventions live in the linked Signal Records.

Educational information — not medical advice

Reference ranges and interpretation vary by laboratory, assay, age, and individual. Use this to understand the science, then interpret your own results with a qualified clinician. See our Medical Disclaimer.

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