A Comparative Study of Conventional Risk Models for Coronary Artery Disease and Computed Tomography Coronary Angiography in the Indian Population

Objectives: The objectives of this study was to evaluate the degree of correlation between conventional risk models such as Framingham risk score (FRS) risk categories, and the burden of coronary artery disease (CAD) as assessed by coronary computed tomographic angiography (CCTA) using calcium score, Coronary Artery Disease-Reporting and Data System (CAD-RADS) score, segment involvement score (SIS), segment stenosis score (SSS), and modified Duke’s prognostic index (MDPI). Methodology: One hundred and forty-four patients with suspected CAD referred for CCTA were included in the study. FRS was determined, and patients were categorized into low, moderate, and high risk. On CCTA, calcium score, CAD-RADS, SIS, SSS, and MDPI were calculated. Correlation between FRS and CT scores was assessed using Pearson’s correlation. Results: Of 144 patients, 21.5% had CAD on CCTA. 10-year FRS of 10%–19% showed 6.8 times higher risk of CAD on CCTA; those with 10-year FRS of ≥20% showed 11.71 times higher risk of CAD as compared to those with FRS <10%. FRS and CAD-RADS, SIS, SSS, and MDPI showed weak-to-moderate correlation ( r = 0.452, 0.401, 0.356, and 0.436, respectively, P < 0.001). No one with FRS <10% showed CADRDAS >3, suggesting a good correlation between FRS and various CT scores. Conclusion: A strong correlation between FRS and CAD burden in the low-risk (<10% risk) group was observed, with none of them showing CAD on CCTA. Obstructive CAD was seen only in the high-risk group (>20%), indicating the importance of imaging in this group to decide preventive measures or therapy.