Heart Calcium Scans Most Useful for Intermediate Risk Patients

Coronary artery calcium scans may be most beneficial for individuals with an uncertain risk of heart disease. A ten-year study involving over six thousand adults found that these scans offer limited additional predictive value for many people. However, for patients categorized as having borderline or intermediate risk, the scans could significantly clarify their likelihood of developing heart disease.

Researchers at Northwestern Medicine conducted the study. They observed that for the general population, adding a coronary artery calcium score provided only a minor improvement over the American Heart Association's PREVENT calculator. The PREVENT calculator estimates cardiovascular disease risk using standard health information like blood pressure, cholesterol, age, and sex.

Coronary artery calcium scans use computed tomography (CT) to detect calcium-containing plaque in the coronary arteries. A higher calcium score generally indicates an increased risk of future cardiovascular disease. The study suggests that these scores become particularly valuable when the PREVENT calculator initially places an individual in a borderline or intermediate risk category, typically a three to nine percent risk over ten years.

For this specific group, the calcium scan offered a clearer indication of who was more likely to experience cardiovascular events. This information can help guide treatment decisions. The study also highlighted potential drawbacks of using scans when they are unlikely to alter a patient's treatment plan. Unnecessary radiation exposure, additional testing, and costs may result without clear clinical benefits.

The study included participants aged forty-five to seventy-nine from the Multi-Ethnic Study of Atherosclerosis. Six percent of participants experienced a heart attack or stroke over the decade. The overall improvement in prediction accuracy when including calcium scores was modest, rising from 0.73 to 0.75. However, the improvement was more substantial for the borderline and intermediate risk groups.

Accurate risk identification helps doctors determine who would benefit most from preventive treatments, such as statins. The findings also support the effectiveness of the PREVENT calculator in predicting cardiovascular risk even without calcium scan results. Further research is needed for higher-risk populations and younger individuals.