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TUESDAY, May 1 (HealthDay News) -- A new drug is no more effective at improving the survival rates of people with decompensated heart failure than a widely used medication is, a new international study has found.
Decompensated heart failure is one form of the general condition in which the heart progressively loses the ability to pump blood. It is characterized by a set of symptoms including shortness of breath and intolerance to exercise.
There were hopes that the new drug, levosimendan, would improve survival, because it uses a unique mechanism that makes heart muscle cells more sensitive to the calcium that causes them to contract. However, the study of 1,347 persons with acute decompensated heart failure, done at 75 centers in nine countries between March 2003 and December 2004, found essentially the same death rate for participants who got levosimendan as those who received an established medication, dobutamine, said a report in the May 2 issue of the Journal of the American Medical Association.
The trial leaves cardiologists without a totally satisfactory treatment for decompensated heart failure, said Dr. Robert Hobbs, a Cleveland cardiologist specializing in treatment of the condition. Some 5 million Americans have one form or another of heart failure, and about 1 million of them are hospitalized for it each year.
"The original therapy, which is still basic, is diuretics," Hobbs explained. "They make the body lose water, so people feel better. In the 1980s, ACE inhibitors came along to make people feel better and live longer, and they were added for long-term benefit. The third group of drugs to be used were beta blockers."
Dobutamine is a beta blocker that has been found to improve symptoms, but it has also been associated with an increased risk of death and cardiovascular problems. In the latest trial, participants with decompensated heart failure received levosimendan or dobutamine intravenously.
"The common practice has been to give dobutamine in the belief that the heart is like a battery that has lost its charge," Hobbs said. "By giving dobutamine, you would recharge it. That didn't actually happen [in previous studies]. It appeared to be associated with complications, longer hospital stays and more mortality."
In another previous study, careful analysis indicated that levosimendan was associated with a lower risk of death than dobutamine. "It did have the different mechanism of action, and it was felt that might translate into improved safety," Hobbs said. But it proved to be no better in the new trial.
In the 180 days after drug infusion, the death rate was 26 percent among patients who got levosimendan and 28 percent in those getting dobutamine. There was no statistical difference between other endpoints, such as incidence of breathing difficulties and days spent out of the hospital.
Participants who got levosimendan were less likely to experience cardiac failure but more likely to experience the abnormal heartbeat called atrial fibrillation, low blood levels of potassium, and headache.
"The bottom line on all of this is that it is hard to show benefit for what we do for acute decompensated heart failure," Hobbs said.
SOURCES: Robert Hobbs, M.D., cardiologist, Cleveland Clinic; May 2, 2007, Journal of the American Medical Association
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