Certain patients may benefit from repeat imaging of the heart’s arteries, based on a recent study that explored the role of coronary artery calcium in future heart risks.
Coronary artery calcium, often referred to as CAC, is the build-up of calcium in the heart’s major arteries. CAC is measured using non-invasive imaging tests and is associated with increased risk for heart events, even in patients who have no symptoms of heart disease.
Since CAC is helpful in predicting future heart risk, experts wonder if more frequent testing could help identify high-risk patients in need of treatment. But based on study results published in the American Heart Association journal Circulation, such frequent testing may only be beneficial for specific patients.
Conducted at the University Clinic Essen in Germany, this study tracked the health of more than 3,200 healthy adults beginning in 2000. Participants underwent imaging to assess CAC upon enrollment and then five years into the study. Researchers then followed participants for an additional eight years, tracking key outcomes like heart attack and stroke.
By the end of the study, there were 241 heart events. Researchers found that greater levels of calcium build-up were associated with significantly greater cardiovascular risk. However, repeat imaging did not improve prediction of cardiovascular risk in those with the lowest and highest levels of CAC.
For example, patients with virtually no calcium build-up at their first scan still had healthy arteries five years later and remained low-risk. Similarly, patients with extremely high levels of calcium build-up at the start of the study still remained high-risk at the second scan.
What findings show, according to authors, is that repeat imaging tests are most useful in patients with moderate levels of CAC. For patients with some calcium build-up, repeat testing may help track whether a patient’s cardiovascular risk increases over time. However, patients with extremely low or high risk can likely rely on initial CAC imaging results when estimating their risk for developing heart disease.