Coronary Artery Calcium Score
A focused measure of calcified coronary plaque that can sharpen prevention decisions for some people—without answering every question about the heart.
The Science
What This Test Measures
A coronary artery calcium (CAC) score measures the amount of calcified plaque in your coronary arteries using a low-dose CT scan. The result is an Agatston score: 0 means no detectable calcium, while higher numbers indicate increasing plaque burden.
CAC can add prognostic information to a standard risk estimate, but the number is not interpreted in isolation. A zero score does not exclude noncalcified plaque, and a higher score needs context from age, sex, risk factors, and the clinical question.
The clearest use is in selected asymptomatic adults at borderline or intermediate risk when a prevention or statin decision remains uncertain. Clinician interpretation connects the score to the broader risk discussion; symptoms require a diagnostic pathway instead.
Interpretation
Questions a CAC Score Can Inform
Whether calcified coronary plaque is detectable
How plaque burden compares with people of similar age and sex
Whether estimated risk may be higher than standard factors suggest
How the result might affect a prevention conversation
Why symptoms require a different diagnostic pathway
When additional imaging may add information—or only noise
Before Testing
How to Think About It
01
Estimate baseline risk
Age, symptoms, family history, blood pressure, smoking, and lipid markers shape whether a CAC score may help.
02
Ask what uncertainty remains
CAC is most useful when its result could resolve a real prevention decision rather than satisfy curiosity alone.
03
Interpret the score in context
The absolute Agatston score, age- and sex-based percentile, and the rest of the risk picture belong together.
04
Know its blind spots
A zero score does not exclude noncalcified plaque, and a high score does not by itself reveal a blockage.
Is This Right For You?
Who This Is For
Selected asymptomatic adults whose estimated risk is borderline or intermediate
A prevention decision remains uncertain after a clinician-patient risk discussion
Risk-enhancing factors leave uncertainty about whether to use a statin
You already have a CAC score and need clinician interpretation
You understand that a zero score does not rule out every form of coronary disease
You want a focused measure that may refine—not replace—a prevention assessment
CAC scoring exposes you to a small amount of radiation and does not evaluate every cause of chest symptoms. New or concerning symptoms need timely medical assessment, not screening alone.