Study Compares Effectiveness Of Heart Drugs

By Linda Carroll, Medical Tribune News Service Researchers have found that an older, less expensive drug may be just as effective in treating congestive heart failure as the newest one on the market.

In a study comparing the two beta-blockers, New York researchers found no benefit to using the newer medication, according to a report published in the American Heart Association journal Circulation. Congestive heart failure (CHF) is a condition in which the heart becomes progressively weaker, leading to shortness of breath and fatigue. Beta-blockers help by blocking the effects of the hormone adrenaline, which is over-produced in CHF patients. Without an adrenaline-blocker, the heart keeps working in overdrive, explained the study's lead author Dr. Marrick L. Kukin, an associate professor of medicine at the Mount Sinai School of Medicine and director of the heart-failure program at the Mount Sinai-New York University Health System in New York. In the new study, Kukin and his colleagues followed 67 patients suffering from CHF.

In the six-month study, 30 patients were treated with the older drug, metoprolol, while 37 received carvedilol, which is the only beta-blocker that currently has Food and Drug Administration approval for treating CHF. Carvedilol, made by SmithKline Beecham, costs about three times as much as the older drug, which several different companies manufacture. Kukin and his colleagues compared the drugs' effectiveness in relieving strain on the heart and improving patients' stamina for exercise. They also checked for differences in patient symptoms, such as breathlessness and fatigue, and in blood levels of anti-oxidants.

The researchers ultimately determined that the two drugs were equal in their effects on CHF patients. The study is important for a number of reasons, according to an Arizona heart expert. First, by showing that more than one beta-blocker can help CHF patients, the study helps confirm theories as to how these drugs may work, said Dr. Joseph S. Alpert, the Flinn Professor of Medicine and the head of the department of medicine at the University of Arizona College of Medicine in Tucson. Heart experts suspect that most of the symptoms of CHF occur because the body overreacts to some type of heart-muscle damage.

A damaged heart muscle doesn't pump as much blood through the arteries and veins, Alpert explained. The body misinterprets the situation and reacts as if severe dehydration or serious bleeding were the cause of the lowered blood flow, he added. To stimulate the heart, the body produces more adrenaline, which simply makes a damaged heart work harder.

``It's like whipping a tired horse,'' Alpert said. ``For a short time the horse goes a little faster, then it falls over. By blocking adrenaline we are, in effect, stroking the horse and giving it a few more oats, giving it a chance to catch its breath so it can work a little longer.'' The idea of giving the damaged heart a break to make it last longer appears to work, Kukin said.

An earlier study found that deaths were reduced by 35 percent among patients who were given a beta-blocker, along with several other standard heart medications, compared with those given only the standard therapies, he added.

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