ApoB/A1 and LDL-C/HDL-C and the prediction of cardiovascular risk in statin-treated patients

Background: It is generally accepted that low density lipoprotein cholesterol (LDL-C) or calculated ratios such as LDL-C to high density lipoprotein cholesterol (HDL-C) (LDL-C/HDL-C) are useful predictors of risk of cardiovascular disease in the primary as well as in the secondary prevention setting. However, there is accumulating evidence that the ratio of the corresponding apolipoproteins (apoB/A1) might be superior in some populations. Little is known with regard to the prognostic significance of apoB/A1 in patients treated with statins according to the guidelines. Objective: The present study assesses the prognostic value of apoB/A1 in such patients receiving statin therapy. Methods: This study was performed in a population of 593 statin-treated patients with known coronary heart disease (CHD). It is a post-hoc analysis of a published study on the effect of folic acid on cardiovascular risk. The association of lipids and apolipoproteins with cardiovascular events was evaluated using univariate and multivariate Cox regression models. Results: The apoB/A1 ratio was associated with clinical outcome when corrected for standard risk factors, whereas LDL-C/HDL-C was not, which could indicate additional significant prognostic value of apoB/A1 over and above this classic lipid ratio. However, this additional prognostic value was not confirmed by receiver operating characteristic (ROC) curves, which showed no increase in the area under the curve. Conclusion: In statin-treated patients with known CHD, apoB/A1 is positively associated with clinical events, whereas the LDL-C/HDL-C is not, but apoB/A1 does not increase the area under the curve.