Interplay Between Lipid-Derived Atherogenic Indices and Coronary Artery Calcium Score in Cardiovascular Risk Assessment

Abstract

Objective: To evaluate the association between lipid-derived atherogenic indices (atherogenic index of plasma (AIP), Castelli Risk Index-I (CRI-I), Castelli Risk Index-II (CRI-II), Atherogenic coefficient (AC), non-HDL-C) and coronary artery calcium score (CACS), and to compare the diagnostic ability of these indices for early diagnosis of coronary artery disease.

Methodology: This cross-sectional analytical study took place at departments of Cardiology, Pathology, and Cardiovascular Imaging at Punjab Institute of Cardiology, Lahore, from 2-05-2025 to 28-01-2026. 188 individuals presenting with chest pain were recruited through consecutive sampling. Blood samples were drawn for fasting lipid profile and HbA1c. AIP, CRI-I, CRI-II, AC and non-HDL-C were then calculated using standard formulae. CACS was determined using the Agatston scoring method on coronary CT angiography. Statistical analysis included Pearson’s correlation, one-way ANOVA, and ROC curve analysis. The optimal cut-off value was identified using Youden’s index.

Results: All the indices showed statistically significant correlation with CACS (p<0.05). AIP showed the strongest positive association (r=+0.278, p<0.001), followed by CRI-I (r=+0.245, p=0.001) and AC (r=+0.245, p=0.001). One-way ANOVA revealed that all indices differed significantly among all four classes of CACS (p<0.05). AIP showed the highest discriminatory ability through ROC analysis (AUC=0.709; 95% CI: 0.636–0.782). The optimal cut-off value of AIP for predicting CAD was >0.27. This threshold yielded a sensitivity of 50.5% and a specificity of 84.6% with an overall diagnostic accuracy of 69%.

Conclusion: AIP, CRI-I, CRI-II, AC and non-HDL-C showed significant positive correlation with CACS. AIP showed the highest diagnostic performance and an AIP cut-off value >0.27 may help in identifying individuals at increased risk of CAD.

Keywords: Atherogenic Indices, Coronary artery disease, Lipid Profile.