Inadequacy of coronary calcium scoring in evaluating coronary artery disease: A call to shifting to high-resolution CT coronary imaging.

Background and aims: Coronary artery calcium (CAC) scoring is an increasingly adopted, non-invasive modality for assessing coronary artery disease (CAD). However, its diagnostic reliability in comparison to invasive coronary angiography (ICA) remains controversial. This study evaluated the diagnostic performance of CAC scoring in predicting CAD using ICA as the reference. Methods: Adults who underwent both coronary computed tomography angiography (CCTA) with CAC scoring and ICA within a three-month interval were retrospectively analyzed between 2018 and 2024. Obstructive CAD was defined as ≥ 50% stenosis on ICA. Patients were stratified by CAC scores: 0 (group 1), 1-399 (group 2), and ≥400 (group 3). Chi-square analysis was utilized to assess the differences in CAC scores compared to ICA. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CAC against ICA were all calculated using R version 4.4.0. Results: Among 110 patients (mean age 53 ± 10; 86.4% males), obstructive CAD was found in 25% of patients in group 1, 56% of patients in group 2, and 79% of patients in group 3 (χ Conclusion: While a CAC score of 400 or higher strongly predicts significant CAD, scores of zero or intermediate values fail to exclude obstructive disease reliably. These findings reaffirm that CAC scoring is a useful stratification tool but should be interpreted with caution, particularly in high-risk patients, and confirmed with ICA when appropriate.