The ratio of apoB/apoAI, apoB and lipoprotein(a) are the best predictors of stable coronary artery disease

BACKGROUND: The ratio of low- to high-density lipoprotein-cholesterol (LDL-C/HDL-C) conventionally represents the balance of proatherogenic and anti-atherogenic lipids. However, growing evidence supports the idea that the ratio of apolipoprotein (apo) B/apoAI is a better index for risk assessment of coronary artery disease (CAD). The aim of this study was to evaluate the efficiency of advanced profile of serum (apo)lipoproteins for predicting stable CAD in secondary prevention. METHODS: The study subjects, 138 men and 126 women aged 40-70 years, were classified as CAD cases or controls, according to the results of coronary angiography. The severity of CAD was scored on the basis of the number and extent of lesions in coronary arteries. Serum (apo)lipoproteins were measured by immunoturbidometric and electrophoresis methods. RESULTS: Patients with CAD compared with controls had increased serum levels of triglycerides (2.6+/-2.0 vs. 2.0+/-1.2 mmol/L, p< or =0.005), apoB (1.36+/-0.31 vs. 1.19+/-0.24 g/L, p< or =0.0001), lipoprotein(a) [Lp(a)] (0.69+/-0.60 vs. 0.43+/-0.31 g/L, p< or =0.0001) and apoB/apoAI ratio (1.07+/-0.32 vs. 0.87+/-0.18, p< or =0.0001), and decreased serum levels of HDL-C (1.02+/-0.29 vs. 1.11+/-0.34 mmol/L, p< or =0.03), apoAI (1.32+/-0.22 vs. 1.37+/-0.19 g/L, p< or =0.04) and LDL-C/apoB ratio (0.91+/-0.32 vs. 1.02+/-0.25 mmol/g, p< or =0.01). Multiple logistic regression analysis after adjusting for major risk factors showed that the apoB/apoAI ratio, apoB and Lp(a) were among seven significant and independent determinants of CAD. The area under the receiver operating characteristic (ROC) curves (AUC) as a relative measure of test efficiency was highest and significant for the apoB/apoAI ratio (AUC=0.71, p< or =0.0001), apoB (0.67, p< or =0.0001), Lp(a) (0.63, p< or =0.001), the LDL-C/apoB ratio (0.62, p< or =0.006), triglycerides (0.62, p< or =0.004) and apoAI (0.58, p< or =0.05). ANOVA analysis showed significant association for the apoB/apoAI ratio, apoB, Lp(a) and triglycerides, and moderate association for total cholesterol and its subfractions, with the severity of CAD. CONCLUSIONS: The results indicate that the apoB/apoAI ratio, apoB and Lp(a) are independent risk factors for CAD and are superior to any of the cholesterol ratios. We suggest using the apoB/apoAI ratio as the best marker of CAD in clinical practice.