Widely used cholesterol-lowering statin drugs may also help the heart recover after a heart attack, Chinese researchers report.
In experiments with pigs, the researchers found that pretreatment with the statin Zocor (simvastatin) was effective in increasing blood flow to the heart after an induced heart attack.
In addition, they found that this beneficial effect worked through potassium in the heart cells, the so-called KATP channel.
"Improving blood flow to the heart is really important to preserve function of the heart after a heart attack," explained David Lefer, from the Division of Cardiology at Albert Einstein College of Medicine, New York City, and author of an accompanying journal commentary. "This paper gives more evidence that statins are good drugs, not just to lower cholesterol, but that during a heart attack they can be beneficial," he said.
The report was published in the Aug. 21 online edition of the British Journal of Pharmacology.
Restoring blood flow to damaged muscle
In an interview, lead researcher Dr Yuejin Yang, from the Fuwai Heart Hospital, Beijing, said the main goal after a heart attack is to restore blood flow to damaged heart muscle.
However, studies have shown that despite complete restoration of epicardial ("around the heart") blood vessel flow, the flow of blood through heart tissue often remains incomplete, a condition known as the "no-reflow" phenomenon. No-reflow has been associated with poor prognosis, Yang said.
"Our study showed that the pretreatment with simvastatin decreased the area of no-reflow, reduced [heart attack] size and improved cardiac function," Yang said.
Yang's team believes these beneficial effects of statins are due, at least in part, to their ability to reduce no-reflow. "Patients taking statins to lower cholesterol may also attenuate myocardial no-reflow and, consequently, improve outcome when suffering a heart attack," Yang said.
Clues to statins' mechanism
For his part, Lefer said these types of heart-healthy effects may help explain the ability of statins to protect against heart attack. "We think it's a combination of cholesterol-lowering and non-cholesterol-lowering effects," he said.
Another expert agreed.
"This study provides additional insights into the mechanisms for the remarkable cardiovascular protective effects of statin medications," said Dr Gregg Fonarow, director of the Ahmanson-UCLA Cardiomyopathy Center and co-director of the UCLA Preventative Cardiology Program.
According to Fonarow, previous studies have shown that statin use in the first 24 hours after a heart attack minimises injury to the heart and boosts patient survival. "As such, starting statin therapy as early in the course of acute coronary events as possible is highly recommended as part of routine clinical practice," Fonarow said. - (Decision News Media, August 2006)
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