Who Actually Needs a Heart Calcium Scan?

Key takeaways

• A 10-year study of more than 6,000 adults found that a popular arterial calcium scan added only modest value on top of standard risk calculators for the average person.
• The scan mattered most for people who landed in a borderline, in-between risk category, helping clarify whether their true risk was meaningfully higher or lower than the initial estimate suggested.
• For people who were already confidently low-risk or already confidently high-risk based on standard factors, the extra scan didn't change the recommended next steps.
• The bigger picture: knowing your baseline numbers first is what tells you whether an additional test is actually likely to be useful, rather than getting every available test by default.

Arterial calcium scans have become an increasingly popular way for people, especially those in their 40s and 50s who are thinking proactively about long-term health, to get a closer look at what's happening inside their arteries. The quick CT scan measures calcium buildup and produces a score that many people interpret as a clearer, more personal number than a standard risk calculator.

But researchers from Northwestern Medicine wanted to know how much the scan actually adds on top of PREVENT, the widely used calculator that estimates long-term risk using information like blood pressure, cholesterol, age, and sex.

What a decade of data showed

The team followed more than 6,000 adults ages 45 to 79 for 10 years, giving each participant both a calcium score and a PREVENT estimate at the outset. When they compared how well each approach predicted what actually happened over the following decade, the difference for the group as a whole was small. Prediction accuracy improved only modestly when the calcium score was added to the standard calculator.

In other words, for most people, the calculator alone already did a fairly good job of estimating their risk trajectory, and the scan didn't meaningfully sharpen that picture.

The zone where the scan actually helps

The story changed when researchers zoomed in on people whose initial PREVENT score placed them in a borderline, in-between range, not clearly low-risk and not clearly high-risk. For this specific group, adding the calcium score produced a meaningfully better read on who was actually likely to face problems down the road and who wasn't.

That distinction matters practically. People confidently at the low end of the risk spectrum didn't gain much from the extra information, and people confidently at the high end were already headed toward the same preventive recommendations regardless of what the scan showed. It's the middle group, the ones sitting in genuine uncertainty, where the extra data point actually changed the picture.

A longevity lens: matching the test to the person

This research is a useful reminder that more testing isn't automatically better testing. Every scan carries some cost, whether that's radiation exposure, expense, or simply the mental load of interpreting an ambiguous number. The most efficient use of a test is when it's likely to change what you do next, not just add another data point to a picture that's already clear.

For anyone in their 40s or 50s building a proactive health strategy, the practical lesson is to start with the basics, blood pressure, cholesterol, and a standard risk calculator, and use that first read to decide whether more specialized testing is likely to be worth pursuing.

The takeaway

Not every tool needs to be used on every person, and this study makes a strong case for a more targeted approach to risk testing. If your numbers put you clearly in the low or high range, an extra scan probably won't change much. But if you land in that ambiguous middle zone, it may be exactly the kind of clarifying data point worth asking your doctor about.

References:

Xiaoning Huang, Lucia C. Petito, Norrina B. Allen, Ron Blankstein, Roger S. Blumenthal, Josef Coresh, Philip Greenland, Jennifer E. Ho, Amit Khera, Donald M. Lloyd-Jones, Janani Rangaswami, James H. Stein, Chiadi E. Ndumele, Sadiya S. Khan, Nilay S. Shah. Predictive Utility of Coronary Artery Calcium Score Added to the PREVENT Equations. JAMA, 2026; DOI: 10.1001/jama.2026.13233