Do lipid lowering drugs reduce the risk of coronary heart disease?

Historically, a wide range of drugs have been used to treat hyperlipidemias. These include fibrates whose main action is to lower plasma triglycerides; bile-acid sequestering resins introduced to reduce plasma cholesterol; and more recently a family of statins designed to inhibit the rate-limiting enzyme of cholesterol biosynthesis, HMG-CoA reductase. Early trials employing rather small numbers of subjects with established coronary artery disease (CAD) demonstrated that lipid reduction was often but not always associated with a lowered incidence of clinical end-points, including death and non-fatal myocardial infarction. However, significant angiographic benefit was rarely demonstrated in these investigations. More recent trials based on statins have shown a reduction in clinical events not only in patients with CAD, but also in healthy subjects given these drugs for primary prevention. Differences in design, duration, the role of confounders such as risk factors other than lipids, and the frequently poor correlation between angiographic changes and clinical outcomes are discussed.