In patients with CAC scores undergoing stress CMR, the prevalence of myocardial ischemia was approximately one-fourth and was associated with higher CAC scores, and stress CMR may influence clinical management in this population.
Myocardial ischemia on stress perfusion CMR was present in about one-quarter of patients with high CAC scores.
The study population was elderly, mostly male, and at intermediate-to-high predicted cardiovascular risk.
CAC score was the only independent predictor of myocardial ischemia.
The association between CAC score and ischemia was consistent across clinical risk categories and diabetes status.
The number of ischemic segments increased with higher CAC scores.
ROC analysis identified an optimal CAC cutoff of ≥1,093 AU for detecting myocardial ischemia, with moderate discrimination.
Stress CMR results were followed by changes in clinical management in a substantial share of patients.
The authors conclude that larger or prospective studies are needed to validate the findings and evaluate prognosis.
This study looked at 215 mostly older patients who had a high coronary artery calcium (CAC) score, a measure of calcium buildup in the heart's arteries, and then had a stress cardiac MRI to check whether parts of the heart muscle were not getting enough blood flow under stress (ischemia). About one in four patients (26%) showed ischemia. It was found in 17% of those with CAC of 300-999 and in 42% of those with CAC of 1,000 or more. Of the factors examined, only the CAC score independently predicted ischemia; the link held regardless of clinical risk score category or diabetes status. Higher CAC scores were also linked with more affected heart segments. A CAC of about 1,093 or above best separated patients with and without ischemia, though this was only moderately accurate (AUC 0.75). After the MRI, 37% of patients had their medications changed and 18% underwent invasive procedures, suggesting the test may influence care for people with high calcium scores. This research suggests CAC score and ischemia are related but not identical, so many patients with very high scores had no ischemia. The authors note that larger, prospective studies are needed to confirm these results and to see how they relate to long-term outcomes.
Kaolawanich Y, Meechuen M, Laohabut I, Ruengchaisiwawaith T, Boonyasirinant T. (2026). Association between coronary artery calcium score and myocardial ischemia assessed by stress perfusion cardiac magnetic resonance imaging.. PloS one. https://doi.org/10.1371/journal.pone.0361659