Northwestern study finds heart calcium scans benefit only borderline-risk patients

September 12, 2026 at 07:32 PM2 min

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A Northwestern Medicine study of more than 6,000 adults found coronary artery calcium scans add little predictive value over the PREVENT risk calculator for most patients. The scans proved most useful for people whose PREVENT score placed them in a borderline or intermediate risk category. The findings, published Aug. 26 in JAMA, suggest routine scanning in low- or high-risk groups may lead to unnecessary radiation, testing, and costs.

Key Facts

The study followed more than 6,000 adults ages 45 to 79 for 10 years using data from the Multi-Ethnic Study of Atherosclerosis.
Adding a coronary artery calcium score to the PREVENT calculator provided only a small improvement in cardiovascular risk prediction for the overall study population.
Calcium scores were most useful for patients whose PREVENT estimate placed them in a borderline or intermediate risk category.
The study was published on Aug. 26 in JAMA.
Senior author Dr. Nilay Shah is an assistant professor of medicine in the division of cardiology at Northwestern University Feinberg School of Medicine.

Study Design

Researchers examined data from more than 6,000 adults ages 45 to 79 who participated in the Multi-Ethnic Study of Atherosclerosis. Each participant received both a coronary artery calcium score and a PREVENT estimate of their 10-year cardiovascular event likelihood at the start of the study. Participants were then followed for 10 years to compare predicted risk with actual cardiovascular outcomes.

Clinical Implications

Dr. Nilay Shah, the study's senior author, said the findings suggest not everyone needs a coronary artery calcium scan for predicting heart attack and stroke risk. Routine scanning in low-risk people may cause unnecessary radiation exposure, testing, and costs with unclear clinical benefits, Shah said. In high-risk patients, calcium scans are unlikely to change treatment because those individuals are recommended to start a statin regardless of the scan result. The PREVENT calculator from the American Heart Association estimates cardiovascular disease risk over 10 or 30 years using blood pressure, cholesterol, age, and sex.