Effects of switching statins on lipid and apolipoprotein ratios in the MERCURY I study

Background Lipid ratios are clinically useful markers of coronary artery disease (CAD) risk. The effects of rosuvastatin, atorvastatin, simvastatin, and pravastatin on lipid ratios were investigated in the Measuring Effective Reductions in Cholesterol Using Rosuvastatin TherapY (MERCURY) I trial. Methods This trial was conducted in 3140 hypercholesterolemic patients with CAD, atherosclerosis, type 2 diabetes mellitus, or a 20% 10-year risk for CAD. Patients were randomized to rosuvastatin 10 mg, atorvastatin 10 or 20 mg, simvastatin 20 mg, or pravastatin 40 mg for 8 weeks; all patients except those receiving rosuvastatin 10 mg either were switched to rosuvastatin 10 or 20 mg or remained on initial treatment for 8 more weeks. Results At 8 weeks, reductions in total cholesterol (TC):high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol:HDL-C, non-HDL-C:HDL-C, and apolipoprotein (apo) B:apo A-I ratios with rosuvastatin 10 mg were significantly greater than those with atorvastatin 10 mg, atorvastatin 20 mg, simvastatin 20 mg, and pravastatin 40 mg (P<0.0001 for all). At week 16, switching to rosuvastatin 10 mg from atorvastatin 10 mg, simvastatin 20 mg, and pravastatin 40 mg and to rosuvastatin 20 mg from atorvastatin 20 mg produced significantly greater reductions in all lipid ratios (P≤0.0001 for all). Switching to rosuvastatin 10 mg from atorvastatin 20 mg produced significantly greater reductions in TC:HDL-C (P<0.025) and apo B:apo A-I (P<0.01). Conclusions Rosuvastatin 10 mg reduces lipid ratios more than equivalent and higher doses of other statins; switching to equal or lower doses of rosuvastatin produces significantly improved reductions in lipid ratios.