The Lipid Research Clinics Coronary Primary Prevention Trial
The Lipid Research Clinics Coronary Primary Prevention Trial tested the efficacy of cholesterol lowering in reducing the risk of coronary heart disease in 3806 asymptomatic, middle-aged men with primary hypercholesterolaemia. The cholestyramine group experienced 8.5 and 12.6% greater reductions in total and low density lipoprotein (LDL), respectively, than those obtained in the placebo group. The cholestyramine group experienced a 19% reduction in risk (p < 0.05) of the primary end-point of definite coronary heart disease death and/or definite non-fatal myocardial infarction. Corresponding and significant reductions were also seen for angina, development of a positive exercise test, and coronary bypass surgery. All-cause mortality was only slightly, and not significantly, reduced in the cholestyramine group, reflecting more violent and accidental deaths in the cholestyramine subjects. When the cholestyramine group was analysed separately, a 19% reduction in coronary heart disease risk was also associated with each decrement of 8% in total cholesterol. Moreover, coronary heart disease incidence in men in sustaining a fall of 25% in total cholesterol, a typical response to the prescribed dosage (24 g/day) of cholestyramine resin, was half that of men who remained at pretreatment level. The Lipid Research Clinics Coronary Primary Prevention Trial findings show that reducing total cholesterol by lowering LDL cholesterol levels, can diminish the incidence of coronary heart disease morbidity and mortality in men at high risk for the disease because of raised LDL cholesterol levels. These results have considerable importance for the prevention of coronary heart disease through cholesterol lowering, at both the clinical and public health levels.