Because elevated serum cholesterol levels are strongly associated with coronary heart disease, cholesterol reduction by 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (or statins) has been assumed to be the predominant, if not the only, mechanism underlying the beneficial effects of these drugs in cardiovascular diseases. Subgroup analyses of large clinical trials, however, have suggested that the beneficial effects of statins may extend to mechanisms beyond cholesterol reduction. Indeed, recent experimental and clinical evidence indicates that some of the cholesterol-independent or "pleiotropic" effects of statins may be mediated through improving or restoring endothelial function, enhancing the stability of atherosclerotic plaques, and decreasing oxidative stress and vascular inflammation.