Heart disease is the leading cause of death in the United States today, and acute myocardial infarctions - heart attacks - make up a considerable number of those deaths. Over 850,000 Americans had a heart attack in 2007 alone. For years, scientists and physicians have sought ways to prevent heart attacks or to blunt their effects when they are happening.
A new international study suggests that folic acid, or vitamin B9, can do just that.
Heart attacks result from a lack of oxygen supply to the heart muscle itself, which has serious consequences because the heart is a highly active muscle that needs a lot of oxygen to work. The early period of low oxygen is called ischemia, but after a time the damage can become permanent, a condition known as an infarct.
An infarct can cause severe tissue scarring, changes in the structure and size of the heart muscle, arrhythmias or abnormal heart rhythms, long-term heart failure, blood clots and increased risk of future heart attacks. The best way to prevent these consequences is to reduce the severity of the initial heart attack.
A group of cardiologists and scientists led by David Kass from Hopkins looked at folic acid, which has long been thought to be able to help heart function. Folic acid is known to have antioxidant properties, which decrease tissue damage by soaking up toxic particles known as free radicals.
The scientists gave folic acid to rats before experimentally inducing heart attacks, to see if the vitamin could decrease the effects of ischemia. In comparison with non-treated controls, rats on folic acid had less heart damage and better recovery from heart attacks. They showed significantly less tissue damage when looked at under a microscope.
A fairly short treatment dose at a high concentration - lasting just one week before the induction of a heart attack - was sufficient to create a protective effect. Overall, the treated rats had infarcts about 90 percent smaller in size than in the untreated controls.
Drawing from these preliminary experiments on mice, researchers concluded that pre-treatment with folic acid can help lessen the severity of tissue damage caused by myocardial infarction, or heart attack.
There are several potential mechanisms for the results observed by the researchers. It is known that the heart continues to pump during a heart attack, often at an even greater rate to compensate for the oxygen decrease caused by an injured heart. This continued high-rate beating is energetically costly for a damaged heart.
Folic acid is known to work in the mitochondrion, the part of the cell that produces chemical energy. This study and others suggest that folic acid could act as a reserve of the cellular energy currency, phosphate, even when the heart muscle is damaged.
The extra phosphate levels provided by folic acid might be enough to tide over the heart until normal oxygen levels are restored, thus reducing the long-term effects of a heart attack.
Current therapy for treating patients after a heart attack involves using a range of medications, including drugs like Lipitor that decrease the buildup of cholesterol in the coronary arteries, as well as drugs like aspirin that thin the blood and reduce inflammation.
Surgery on the heart muscle or on the coronary arteries, either with angioplasty or an arterial bypass, may also be performed.
The next step is a study of the effects of folic acid on human heart attack patients. A major complication is the dose: The mice received a dose that would be very difficult for people to take orally on a regular basis.
Folic acid is found in a variety of vegetables and is a common ingredient in multivitamins. Previous studies have indicated beneficial effects of folic acid on the brain and other organs.
It has also long been known that taking folic acid during pregancy reduces the risk of spina bifida, a birth defect that causes mental retardation and paralysis.
If the results of this study, which appears in this week’s issue of the journal Circulation, are replicated in humans, they could provide an easy way to help reduce the severity of heart attacks in hundreds of thousands of patients.
Tags: abnormal heart rhythms, antioxidant properties, arrhythmias, blood clots, cardiologists, david kass, free radicals, heart attack, heart attacks, heart damage, heart failure, heart function, heart muscle, infarct, lack of oxygen, leading cause of death, oxygen supply, tissue damage, toxic particles, vitamin b9
