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This study of 215 patients examined the relationship between coronary artery calcium (CAC) scores and myocardial ischemia detected by stress cardiac MRI. Results showed that 26% of patients had myocardial ischemia, with prevalence increasing from 17.1% in those with CAC scores of 300-999 to 41.6% in those with scores ≥1,000 Agatston units. A CAC score of ≥1,093 was identified as the optimal threshold for predicting ischemia, and the findings led to changes in clinical management for over half of patients.
Why it matters
This research helps clinicians determine which patients with elevated calcium scores would benefit from additional stress imaging to detect functional ischemia rather than just anatomical disease. The findings could improve risk stratification and guide treatment decisions, as stress CMR results influenced medication changes in 37% of patients and led to invasive procedures in 18%.
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by Yodying Kaolawanich, Methat Meechuen, Issarayus Laohabut, Thanawat Ruengchaisiwawaith, Thananya Boonyasirinant
Background
Coronary artery calcium (CAC) scoring effectively stratifies cardiovascular risk, and stress perfusion cardiac magnetic resonance (CMR) accurately detects myocardial ischemia. We aimed to investigate the prevalence and factors associated with myocardial ischemia on CMR in patients with CAC, and to assess the clinical impact of myocardial ischemia following CMR.
Methods
This study included 215 patients aged ≥18 years who underwent CAC scoring for risk stratification, followed by stress CMR between 2013 and 2026. The prevalence and predictors of myocardial ischemia were investigated. Receiver operating characteristic (ROC) analysis was performed to assess the association between CAC scores and myocardial ischemia. Additionally, subsequent clinical management following CMR was determined.
Results
The mean age was 69.3 ± 9.1 years (60.9% male). The average 10-year PREVENT risk score was 18.6 ± 8.7%. Overall, myocardial ischemia was present in 26.0% of patients (56/215): 17.1% in the CAC 300–999 Agatston units (AU) group (14/82) and 41.6% in the CAC ≥ 1,000 AU group (42/101). CAC score was the only independent predictor of myocardial ischemia (adjusted OR 1.07, 95%CI 1.03 − 1.10; p 0.05).The number of ischemic segments increased with increasing CAC scores (p < 0.001). ROC analysis demonstrated an optimal cutoff threshold of CAC ≥ 1,093 AU for detecting myocardial ischemia (AUC 0.75, p < 0.001). The clinical impact of stress CMR included medication changes in 37.2% of patients, while 18.1% underwent invasive procedures.
Conclusions
In patients with CAC scores undergoing stress CMR, the prevalence of myocardial ischemia was approximately one-fourth and was associated with higher CAC scores. Stress CMR may influence clinical management in this population. Larger or prospective studies validating these findings and evaluating prognosis are warranted.