New Heart Attack Drug Holds PromiseEplerenone helps reduce risk of death and hospitalizations< April 1, 2003 > Heart attack patients with heart failure who added a new drug to their daily regimen significantly reduced their risks of hospitalization or death. The findings, from a large international study, could signal the beginning of a new era in treating patients with different heart conditions. "A lot of people felt that if patients were on ACE inhibitors and beta blockers, we had done everything we could, that we had exhausted that strategy," says study author Dr. Bertram Pitt, a professor of medicine at the University of Michigan School of Medicine. "This is also important, and it may have implications for heart failure and heart attacks and maybe lots of other cardiovascular disease." The findings were released during the recent annual scientific sessions of the American College of Cardiology in Chicago. They also appear in the New England Journal of Medicine. A heart attack, or myocardial infarction, occurs when one or more regions of the heart muscle experience a severe or prolonged decrease in oxygen supply caused by blocked blood flow to the heart muscle. The blockage is often a result of atherosclerosis - a buildup of plaque, known as cholesterol, and other fatty substances. Plaque inhibits and obstructs the flow of blood and oxygen to the heart, thus reducing the flow to the rest of the body. If the blood and oxygen supply is cut off severely or for a long period of time, muscle cells of the heart suffer severe and devastating damage and die. The result is damage or death to the area of the heart that became affected by reduced blood supply. New drug approved for treatment of high blood pressureThe drug, eplerenone, works by blocking the action of the hormone aldosterone. Although eplerenone was recently approved by the US Food and Drug Administration (FDA) to treat high blood pressure, it is not yet approved to treat heart attack patients. Scientists have known about the hormone aldosterone for half a century but did not realize its significance in heart health until recently. "It's an old friend, but no one thought it was very important," Pitt says. "It's been a neglected friend. No one knew it was so important." In 1999, the RALES study showed that another drug, spironolactone, which blocked the same hormone, reduced deaths by 30 percent and hospitalizations by 35 percent in patients with severe heart failure. Spironolactone is now commonly used for heart failure patients. In the new trial, 6,632 patients in 37 countries were randomized to receive eplerenone (25 milligrams a day to start, moving to 50 milligrams a day after one month) or a placebo. Most of the patients also received standard therapies for their condition, namely ACE inhibitors (taken by 87 percent of the participants), beta blockers (75 percent), aspirin (88 percent), and diuretics (60 percent). All of the patients had had a heart attack three to 14 days before enrolling in the study, as well as problems with the functioning of their left ventricle. They were followed for about 16 months. Eplerenone reduced deaths from heart attackIndividuals taking eplerenone had 15 percent fewer deaths compared to the placebo group, and 13 percent fewer cardiovascular-related deaths and cardiovascular hospitalizations. The differences were even more striking among participants who were taking other therapies (including an ACE inhibitor, beta-blocker, aspirin, and statin) and who had undergone coronary reperfusion, a procedure to improve blood flow. They experienced a 26 percent reduction in deaths. This group also experienced a 21 percent overall reduction in sudden cardiac death and 15 percent fewer hospitalizations for heart failure. The fact that eplerenone also reduced the incidence of sudden death suggests it may be used in place of defibrillators at some point in the future. "Maybe this drug can help to reduce sudden death and in a lot of people we won't need a defibrillation," Pitt says. "It's very expensive to put a defibrillator in people." More research is neededIt is not clear exactly why eplerenone is effective, and it is likely that more than one mechanism is at work, researchers say. More studies will be needed to determine this and also to pinpoint which populations will benefit from the drug. Because this trial's population was 90 percent Caucasian and 71 percent male, minorities and women were not well represented. Researchers are interested to see what other conditions the drug might treat. "I think eplerenone will have a direct impact on people with heart attack and maybe also with people with not-so-bad [heart] function," Pitt says. People with high blood pressure, hypertension, renal disease, valvular disease, and diabetes may also be helped. "There are lots of applications for this," Pitt says. Always consult your physician for more information.
Online Resources(Our Organization is not responsible for the content of Internet sites.) American College of Cardiology National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health (NIH) US Department of Health and Human Services US Food and Drug Administration (FDA) |
For more information on cardiovascular disease and heart attack, please visit the Cardiovascular Diseases health information module on this Web site. What Are the Warning Signs of a Heart Attack?The following are the most common symptoms of a heart attack. However, each individual may experience symptoms differently. Symptoms may include:
Although chest pain is the key warning sign of a heart attack, it may be confused with indigestion, pleurisy, pneumonia, or other disorders. Always consult your physician for more information. Aspirin Resistance Increases Risk for Heart Attack and StrokeAspirin significantly reduces the risk of heart attack and stroke in many patients with cardiovascular disease, and millions take it to lower their risk. However, "People who are aspirin-resistant have an increased chance of having a heart attack or stroke," says Dr. Patricia A. Gum, lead author of a new study. Aspirin helps prevent heart attacks and strokes by blocking the formation of a chemical in the body called thromboxane, which makes platelets sticky and helps to promote blood clotting. But for some people, aspirin does not block this chemical, thus eliminating aspirin's protective effect. Gum and her colleagues from the Cleveland Clinic studied 326 patients with stable cardiovascular disease. These patients had been taking daily doses of 325 milligrams of aspirin for a week or more when enrolled in the study, according to a recent report in the Journal of the American College of Cardiology. The researchers then tested for aspirin resistance. They found that 17 patients were aspirin-resistant. All the patients were followed for almost two years. During that time, four of the 17 patients (24 percent) who were aspirin-resistant had a heart attack or stroke or died, compared with 30 of the 309 patients (10 percent) who were not aspirin-resistant. "We now have more evidence that the diagnosis of aspirin resistance is a clinically real and important diagnosis, which has clinical implications," Gum says. It may be premature to recommend that people be tested for aspirin resistance until better tests are developed, Gum says. However, testing for aspirin resistance may become standard in the future, she adds. However, Gum says she believes that aspirin resistance is clinically important, and patients taking aspirin to reduce their risk of heart attack should talk with their physician about this problem. Dr. Robert Califf, professor of cardiology at the Duke University School of Medicine, says that much larger studies are needed to "sort out the clinical implications of this complex individual response. "It's fascinating to reflect on how little we know about aspirin dosing more than 100 years after the introduction of aspirin as a therapeutic agent," he says. Always consult your physician for more information. |
