CAC Score — The 10-Minute Scan
See plaque with your own eyes
Coronary artery calcium (CAC) scoring is a 10-minute, non-contrast CT scan that counts calcified plaque in your coronary arteries. The score — the "Agatston score" — goes from 0 (pristine) into the thousands. It's the single strongest visualisation of your cardiovascular trajectory.
The MESA findings
The Multi-Ethnic Study of Atherosclerosis (MESA) followed 6,800 people for over a decade. CAC score outperformed every traditional risk factor combined for predicting cardiac events. A CAC of 0 — in someone without diabetes — drops 10-year event risk by ~80% vs calculator predictions.
Interpret the score
Match each CAC score band to its risk tier.
Cost, radiation, access
Typical cost in the US: $75–250 cash price (often cheaper than a copay). Radiation: ~1 mSv, roughly 4 months of background radiation — similar to a cross-country flight. Usually no referral needed at dedicated cardiac imaging centers.
When to get one
Mainstream guidelines: 40–75 with intermediate risk. Preventive-cardiology practice: anyone over 40, especially if family history suggests early disease. Repeat every 5 years if non-zero, or if risk factors change. The scan is cheap insurance against finding out via ambulance.
Key Takeaway
CAC scoring is the most underused, highest-leverage cardiovascular test in medicine. Ten minutes, under $250, outperforms every risk calculator. If you're over 40 and haven't had one, it's almost certainly the next thing to book.