Comparative diagnostic performance of coronary CT angiography and invasive coronary angiography in patients with suspected coronary artery disease

Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Although invasive coronary angiography (ICA) is the reference standard for diagnosing CAD, coronary computed tomography angiography (CCTA) has emerged as a valuable non-invasive alternative. This study compared the diagnostic performance of CCTA with ICA in patients with suspected CAD. In this descriptive cross-sectional study, 155 patients who underwent both CCTA and ICA were included. Coronary stenosis was classified as mild (1–49%), moderate (50–69%), or severe (≥ 70%). ICA served as the reference standard. Diagnostic performance was evaluated using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy. The mean age of the patients was 57.3 ± 9.15 years, and 67.7% were male. CCTA demonstrated a sensitivity of 96.0%, specificity of 33.3%, PPV of 85.7%, NPV of 66.7%, and an overall accuracy of 83.9%. The LAD showed the highest vessel-based sensitivity (87%), whereas the LCX had the lowest (60%). CCTA correctly identified all cases of moderate stenosis and detected 69% of severe stenoses. CCTA demonstrated high sensitivity for detecting CAD but relatively limited specificity in this high-risk population. These findings support its role as a useful non-invasive diagnostic tool, while ICA remains the reference standard for confirming coronary artery stenosis.