Statins and the Myocardium

Cardiac hypertrophy and heart failure are leading causes of morbidity and mortality worldwide. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, have been shown to inhibit cardiac hypertrophy and improve symptoms of heart failure by cholesterol-independent mechanisms. Statins block the isoprenylation and function of members of the Rho GTPase family, such as Rac1 and RhoA. Because Rac1 is a requisite component of NADPH oxidase, which is a major source of reactive oxygen species in cardiovascular cells, the ability of statins to inhibit Rac1-mediated oxidative stress contributes importantly to their inhibitory effects on cardiac hypertrophy. Furthermore, inhibition of RhoA by statins leads to the activation of protein kinase B/Akt and upregulation of Type 3 nitric oxide synthase in the endothelium and the heart. This activation and upregulation results in increased angiogenesis and myocardial perfusion, decreased myocardial apoptosis, and improvement in endothelial and cardiac function. Because these effects of statins occur independent of cholesterol lowering, statins may have therapeutic benefits in nonhyperlipidemic patients with cardiac hypertrophy and heart failure.