Statins are well-known, cholesterol-lowering agents. They are competitive inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, which is the key enzyme catabolizing the early rate-limiting step in the bio¬synthesis of cholesterol within the hepatocyte. They lower LDL cholesterol in blood and thus prevent heart attacks and death from myocardial infarction as well as strokes. More important, statins have been shown to prevent lipo-protein oxidation, and it is believed that some of their salutary effects may be related to this action. They appear to improve survival in patients with ischemic and non-ischemic heart failure. Nitric oxide synthesis is diminished in heart failure; statins enhance endothelial NO synthase (eNOS) activity and improve endothelial function (see the section Statins in the Dyslipidemia chapter).