Coronary Artery Calcium (CAC) Screening

Yes. This is one of the most important things to understand about CAC screening. A score of 0 means no calcified plaque was detected, but it doesn't rule out non-calcified (soft) plaque, which is earlier-stage and often more prone to rupture. People with elevated Lp(a), high LDL particle counts (ApoB or LDL-P), or significant insulin resistance can have meaningful atherosclerotic burden that simply hasn't hardened yet. A zero is excellent news, but it needs to be read alongside the rest of your biomarker profile.

There's no universal threshold that automatically triggers treatment. It depends on your age, ethnicity, gender, other risk factors, and what biomarkers show. That said, a CAC score above 100 is generally considered significant enough to support starting statin therapy in most adults, and a score above 300 (or above the 75th percentile for your age and sex) typically warrants aggressive risk reduction. A score of 0 in an intermediate-risk patient often supports deferring statins. The score is most useful as a tie-breaker alongside your full risk picture, not a standalone directive.

Most guidelines suggest that a score of 0 provides reassurance for approximately 5–7 years. This is sometimes referred to as the "warranty period." After that window, or sooner if your risk factors change significantly, a repeat scan may be worthwhile. For those with elevated scores, repeat scanning is sometimes used to track plaque progression, though the value of serial testing is still an active area of research. Your physician can help determine the right interval based on your overall risk profile.

Usually not, though this is changing. Most commercial insurance plans and Medicare don't routinely cover CAC screening outside of specific clinical criteria. The good news is the test is inexpensive and typically $100–200 out of pocket at most imaging centers. It typically doesn't require a physician's order in most states. You can often schedule it directly. You can find a list of noninvasive imaging centers here or use a resource like the MESA CAC center locator to find a location.

They measure very different things. A stress test evaluates how well your heart functions under exertion. It is good at detecting significant blockages that are already affecting blood flow. A CAC scan evaluates structure. Different than a stress test, it shows whether plaque has formed in your coronary arteries, even before any blockage or symptoms exist. CAC is a screening tool for detecting early or subclinical atherosclerosis; a stress test is more appropriate when symptoms like chest pain or shortness of breath are already present. Most people who benefit from CAC screening would have a normal stress test.

This is the most common situation. A CAC score without the context of your lipid particle counts, inflammatory markers, Lp(a), and metabolic health, and other risk factors, only tells part of the story. The number itself doesn't tell you whether your LDL is actively building more plaque, whether inflammation is destabilizing what's there, or whether genetic factors like elevated Lp(a) are driving risk that the scan can't see. The Precision Health Reports Cardiometabolic Risk Assessment was built to answer exactly this: what does your CAC score actually mean, given everything else going on?