Coronary Artery Calcium (CAC) Score

The coronary artery calcium (CAC) score is one of the most powerful and cost-effective cardiac screening tests available. It uses a brief, non-contrast, low-dose CT scan (typically under $100–$200) to quantify the amount of calcified plaque in your coronary arteries, expressed as an Agatston score. The test takes less than 10 minutes and requires no special preparation.

The power of the CAC score lies in its ability to reclassify risk. A score of zero is enormously reassuring — in a person with no symptoms, a CAC of 0 is associated with a very low 10-year cardiovascular event rate (<1–2%), regardless of what other risk factors are present. This finding can reasonably justify a more conservative approach to statin therapy in otherwise borderline-risk individuals. Conversely, a score above 100 indicates significant coronary calcification, and scores above 400 identify individuals at very high risk who warrant aggressive lipid management and close monitoring.

The main limitation of CAC scoring is that it only detects calcified (hard) plaque — the form that has already undergone years of remodeling. Non-calcified (soft) plaque, which is actually more dangerous because it is prone to rupture, is invisible on a CAC scan. This means a CAC of 0 does not guarantee the absence of all plaque — it is possible (though uncommon) to have significant soft plaque with a zero calcium score. For this reason, some longevity physicians use CAC as a first-line screening tool and follow up with CT coronary angiography (which detects all plaque types) when clinical suspicion is high.