Statin therapy alters the relationship between apolipoprotein B and low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol targets in high-risk patients: the MERCURY II trial.

Description

The Measuring Effective Reductions in Cholesterol Using Rosuvastatin Therapy II (MERCURY II) trial was designed to examine the effect of statin therapy in patients at high coronary heart disease (CHD) risk. Given that high-risk patients often have higher baseline levels of apoB than predicted by their LDL cholesterol levels, the main objective of these post-hoc analyses of the MERCURY II trial was to compare concentrations of LDL cholesterol, non-HDL, and apolipoprotein B before and during statin therapy. At baseline, apolipoprotein B correlated with LDL cholesterol (r2=0.61) and with non-HDL cholesterol (r2=0.79), and the apolipoprotein B target of <90 mg/dl was routinely equivalent to an LDL cholesterol level of <100 mg/dl. However, the study’s main finding was that, in patients with high triglyceride levels at baseline determined to reach apolipoprotein B goals, on-treatment LDL cholesterol had to reach either <70 mg/dl or non-HDL cholesterol levels had to reach <100 mg/dl in order for apolipoprotein B to reach levels <90 mg/dl. In patients with lower triglycerides at baseline, on-treatment LDL cholesterol had to reach either <80 mg/dl or non-HDL cholesterol levels had to reach 100 mg/dl in order for apolipoprotein B to reach levels <90 mg/dl. These results indicate that to drive the atherogenic particle concentration down to the proposed apolipoprotein B target value of <90 mg/dl, it is necessary for statin therapy to achieve LDL cholesterol levels that are much lower than those suggested by current recommendations. Based on these findings, the investigators of MERCURY II suggested that LDL cholesterol levels <70 mg/dl and non-HDL cholesterol levels <100 mg/dl are reasonable targets for patients at increased CHD risk.