Coronary Artery Calcium (CAC) Score: What It Means and When to Use It

A guide to CAC scoring, how it works, and when it helps refine heart disease risk.

Intro

A coronary artery calcium (CAC) score measures calcified plaque in the coronary arteries.

It is one of the most powerful tools for refining cardiovascular risk.


Key Points

  • CAC directly measures atherosclerosis
  • Score of 0 → low short-term risk
  • Higher scores → higher event risk
  • Useful in borderline or uncertain cases

🚨 Breakout: Why CAC Is Different

Most tests estimate risk.

CAC shows whether disease is already present.


How It Works

A CT scan detects calcium deposits in coronary arteries.

Results are expressed as a score:

  • 0 → no detectable plaque
  • 1–100 → mild plaque
  • 100+ → increasing risk

When It’s Used

  • Intermediate risk patients
  • Uncertain treatment decisions
  • Family history of early heart disease

Risks / Limitations

  • Small radiation exposure
  • Does not detect soft plaque
  • Not needed for very low or very high risk

FAQ

Q: Is a CAC score of 0 a guarantee?
A: No—but it suggests low short-term risk.

Q: Should everyone get a CAC scan?
A: No—targeted use is key.


Further Reading