Influence of baseline lipids on effectiveness of pravastatin in the CARE trial

Objectives. We sought to assess the influence of baseline lipid levels on c oronary event rates and the effectiveness of pravastatin therapy in the Cho lesterol And Recurrent Events (CARE) study. Background. The CARE study cohort provided a relatively unique opportunity to examine the relation between lipid levels and clinical events in a post- myocardial infarction (MI) population with relatively low cholesterol and l ow density lipoprotein (LDL) cholesterol values. Methods. There were 4,159 patients with a previous infarct and a total chol esterol level <240 mg/dl, LDL cholesterol level 115 to 174 mg/dl and trigly ceride level <350 mg/dl randomly allocated to placebo (n = 2,078) or pravas tatin 40 mg/day (n = 2,081). Time to either coronary death or nonfatal MI ( primary end point) or to the secondary end point, which included undergoing a coronary revascularization procedure, was determined as a function of ba seline lipids (total, LDL, high density lipoprotein [HDL] cholesterol and t riglyceride levels). Results. Quartile analysis indicated important effects for LDL cholesterol, in which a higher LDL was associated with greater cardiac event rates tin the placebo group, every 25-mg/dl increment in LDL was associated with a 28 % increased risk [5% to 56%, p = 0.015]) in the primary event. The differen tial event rates with respect to baseline LDL cholesterol for placebo and p ravastatin groups reduced the difference in clinical outcomes at lower LDL cholesterol levels. In both the placebo and pravastatin groups, an inverse relation between baseline HDL cholesterol and cardiac events was observed ( 10 mg/dl lower baseline HDL cholesterol level was associated with a 10% [0% to 19%, p = 0.046] increase in coronary death or nonfatal MI). Conclusions. Within the LDL cholesterol levels in CARE (115 to 174 mg/dl), baseline values influenced both the risk of events in the placebo group as well as the clinical effectiveness of pravastatin therapy. (C) 1998 by the American College of Cardiology.