Statins may have a key role in treating heart attacks as well as preventing them, new research suggests.
Scientists in Beijing, China, have shown how the cholesterol-lowering drugs are also able to kickstart blood flow to cardiac muscle once a heart attack has occurred. This novel beneficial action is reported in a study published online this week in the British Journal of Pharmacology. The research suggests this action only needs a few days of treatment, is independent of cholesterol lowering and helps the heart to recover after an infarction.
Following a heart attack, blood does not flow correctly into vessels in the heart, even after they are open again. Increasing blood flow into the arteries would reduce the amount of heart muscle killed through lack of oxygen and also help restore ventricular function.
Dr Jing-Lin Zhao and colleagues of Fu-Wai Heart Hospital in Beijing discovered this new benefit of statin treatment when testing the effects of statins in pigs that had heart attacks induced in them. Just two days' treatment with 2mg per kg/day of the statin simvastatin increased blood flow and preserved ventricular function following a heart attack. The treatment significantly reduced the amount of dead heart tissue compared to control animals, and reduced by 57% the amount of heart muscle that continued to have poor blood flow days after the infarction.
The researchers claim to have identified the mechanism underlying this cardioprotective function: namely that simvastatin appears to activate the KATP channel in mitochondria. This was shown by experiments in which the beneficial effect was abolished by blocking these ion channels.
Dr Zhao said that, ideally, further studies in which animals were followed up for a longer period would be carried out. He added, however, that the results in this study were sufficiently strong to suggest that statins were almost certainly benefiting patients already. “Patients under treatment with statins for conditions such as high cholesterol may also show an improved outcome after suffering a myocardial infarction,” he said.
In addition to their well-documented success in reducing danger blood lipids, heart specialists have suspected for several years that statins act in additional ways to protect the cardiovascular system.
Some research has suggested they benefit patients by increasing levels of NO in the blood and in this way decrease the inflammation that leads to arterial plaques.
The latest Chinese results reveal a completely new mode of action, however, and experts hailed their clinical importance.
In an accompanying article, David Lefer, professor of pathology at the Albert Einstein College of Medicine in New York said: "The findings of the present study have very profound implications for the treatment of cardiovascular disease.” By Michael Day.