Efficacy of drug intervention for lipids in the prevention of coronary artery disease

Abstract

Meta-analysis of the benefit of drug intervention in hypercholesterolaemia has produced conflicting conclusions, dependent upon which studies were included or which outcomes were considered. We have approached this question by considering coronary artery disease (CAD) outcomes, fatal and non-fatal, in studies considered to be pivotal--those of sufficient size and duration and those achieving sufficient cholesterol reduction to be likely to have a statistically significant outcome. In parallel, we have reviewed all the published angiographic trials of adequate design (randomised and controlled). In four pivotal primary prevention studies, CAD morbidity was reduced in the range 19-45%. CAD mortality was reduced significantly in one of these studies. Women were included in only one study and they did not exhibit the favourable outcome observed in men. In four pivotal secondary prevention studies, CAD morbidity was reduced in the range 5-36%. CAD mortality was significantly reduced in two studies. In eight angiographic intervention studies, lipid intervention was associated with consistently more evidence of regression or stable coronary disease. These studies also yielded suggestive evidence of improved clinical outcome. We conclude that drug intervention to lower cholesterol levels effectively reduces CAD morbidity and mortality in men already suffering from CAD (and may do so in women). Treatment is similarly effective in men with hypercholesterolaemia having no prior history of CAD. We lack evidence of the value of treatment in the elderly or in women having no prior CAD.