Cholesterol medication may repair heart

The drug pravastatin--the generic name of one of the statins currently prescribed to lower cholesterol--may provide a previously unknown cardiovascular benefit in addition to lowering lipids. Researchers at the University at Buffalo (N.Y.) have found that it increases the concentration of endogenous stem cells that may participate in cardiac repair independent of any cholesterol-lowering action.

Scientists also discovered that high doses improved cardiac function and coronary blood flow in an animal model in which flow had been artificially restricted, creating a condition known as hibernating myocardium (where heart cells reduce their function and oxygen needs and become dormant in response to insufficient blood flow).

"It is well known that stem cells have the potential to regenerate organs," relates Gen Suzuki, research assistant professor in the School of Medicine and Biomedical Sciences. "In the field of cardiology, adult stem cells isolated from bone marrow currently are being used to repair damaged heart tissue. Many animal and early clinical studies using this source of stem cells are ongoing right now."

Earlier reports have shown that HMG-CoA reductase inhibitors, known as statins, increase the number of circulating bone-marrow-derived or hemotopoietic stem cells in blood, but most work has focused on their effects in improving blood flow. Their Iocalization in the heart or ability to promote cardiac-muscle-cell numbers never has been studied before.

"Statins have been widely employed to reduce coronary events and improve prognosis in patients with established coronary artery disease, as well as for primary prevention in patients with high cholesterol that have other coronary risk factors," notes John Canty, Albert & Elizabeth Rekate Chair in Cardiovascular Disease. "The mechanisms responsible for their favorable effects have largely focused on the blood vessel wall. Stabilization of atherosclerotic plaques and improvement in endothelial-mediated blood vessel relaxation have been thought to be the major explanations for their beneficial actions.

"These new findings raise the possibility that statins can also recruit endogenous repair of cardiac muscle cells in some disease states. This could lead to a broader application in treating heart failure arising from cardiac-muscle-cell loss."

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