Association between Lowering Low-Density Lipoprotein Cholesterol with Pravastatin and Primary Prevention of Cardiovascular Disease in Mild to Moderate Hypercholesterolemic Japanese

Abstract

To evaluate the relationship between low-density lipoprotein cholesterol (LDL-C) change and reduction of cardiovascular disease in the Management of Elevated cholesterol in the primary prevention Group of Adult Japanese (MEGA) study. Patients in the diet plus pravastatin group were divided into tertiles by their on-treatment LDL-C level, and the hazard ratios (HRs) in each tertile were compared with the diet group at 5 years using the Cox proportional hazards model. In addition, the treatment groups were combined and divided into quintiles according to the on-treatment LDL-C level during follow-up, and the incidence of cardiovascular events was compared among the 5 groups. In the tertiles of the diet plus pravastatin group, HR was lowest in the second tertile against the diet group (HR 0.57, p=0.01) with on-treatment LDL-C range of 119.8-133.4 mg/dL. In the analysis of quintiles of the total population, a significant risk reduction of CVD was found in the fourth quintile (HR 0.48, p=0.0015) with an on-treatment LDL-C range of 120.9-133.3 mg/dL, and in the fifth quintile (HR 0.64, p=0.048) with an on-treatment LDL-C range of 56.7-120.8 mg/dL against tertile 1 with an on-treatment LDL-C range of 157.5-206.2 mg/dL. The usual Japanese dose of pravastatin therapy is sufficient in this low-risk patient population to reduce cardiovascular risk, with an achieved LDL-C level <133.4 mg/dL. Further risk reduction was not found with an achieved LDL <120 mg/dL.