Apolipoproteins and the ApoB/ApoA-1 Ratio as Superior Diagnostic and Prognostic Markers for CAD in a Pakistani Population

Background & Objectives: Apolipoproteins, specifically ApoA-I (a cardioprotective HDL component) and ApoB (associated with cardiovascular risk), are increasingly recognized for their value in diagnosing and predicting heart disease. This study focused on comparing these markers and the ApoB/ApoA-I ratio with traditional lipid profiles to assess their diagnostic and prognostic capabilities. Methods: In this cross-sectional study, 1,200 participants were categorized into three groups: control (n=250), training (n=450), and validation (n=500). Blood samples were analyzed for ApoB, ApoA-I, and conventional lipid profile. Advanced statistical methods, including logistic regression, ROC curve analyses, and propensity score matching, were applied to control for confounding factors and validate findings. Results: The training cohort showed significantly higher ApoB levels (1.20 ± 0.52 g/L) compared to controls (1.0 ± 0.40 g/L, p < 0.001), while ApoA-I levels were significantly lower (1.03 ± 0.34 g/L vs. 1.12 ± 0.34 g/L, p = 0.045). The ApoB/ApoA-I ratio was markedly elevated in the training group (1.46 ± 0.18) versus controls (1.06 ± 0.95, p < 0.001). ApoB proved to be the most reliable predictor of coronary artery disease with an AUC of 0.82, surpassing the ApoB/ApoA-I ratio (AUC 0.70) and ApoA-I (AUC 0.65). Cholesterol and triglycerides demonstrated weaker associations with CAD. Conclusion: ApoB and the ApoB/ ApoA-I ratio are superior markers for assessing CAD risk compared to traditional lipid profile. This investigation lends further support for incorporating apolipoprotein testing into clinical practice, enhancing CAD risk stratification, in particular for the high-risk population.