Coronary artery calcium (CAC) scans have been gaining popularity as a quick, relatively affordable way to gauge heart disease risk — but a new Northwestern Medicine study says the benefit may be more targeted than previously thought. Researchers tracked over 6,000 adults for 10 years and found that, for the general population, adding a calcium score offered only a modest improvement over the American Heart Association's PREVENT risk calculator, which uses standard data like blood pressure, cholesterol, age, and sex.

The real value showed up in a specific group: patients whose PREVENT scores placed them in the borderline or intermediate risk range (a 3–9% chance of a cardiovascular event within 10 years). For them, the calcium scan provided a clearer picture of whether their actual risk was higher or lower — information that could meaningfully guide treatment decisions like starting a statin.

Key Takeaways:

• For low-risk patients, routine calcium scans may lead to unnecessary radiation, costs, and testing with little clinical benefit
• For high-risk patients, scans are likely redundant — statins are already recommended regardless of results
• The PREVENT calculator alone performed well at predicting cardiovascular risk, even without calcium scores
• More research is needed in higher-risk groups, including South Asian and Filipino adults, and in younger populations

Why it matters: With heart disease still the leading cause of death in the U.S., precision in risk assessment is critical. This study helps clinicians identify who truly stands to gain from a calcium scan — making care more efficient and reducing unnecessary testing.