WEDNESDAY, March 2 (HealthDay News) -- Answering lingering questions about the treatment of acute heart failure, investigators have determined that there are no real differences in how patients fare when they're given diuretic therapy one dose at a time or continuously.

Nor was there any real difference in outcomes with the lower versus the higher dose, although there was a trend toward improvement the higher the doctors went.

These findings should make decisions easier for the doctors around the United States who treat the one million heart failure patients who are hospitalized each year.

"Today doctors all over the U.S. are having to make a decision on how to give diuretics. This gives insight as to the trade-off between efficacy and safety in each decision," said Dr. Michael Felker, lead author of a study appearing in the March 3 issue of the New England Journal of Medicine.

Loop diuretics have been the mainstay of treatment for acute heart failure for 40 or 50 years, but because the drugs were introduced so long ago, they weren't subject to the rigorous evaluation that today's pharmaceuticals undergo before hitting the market.

Scientists are on the hunt for newer and better treatments for acute heart failure, but in the meantime, diuretics are the standard treatment.

As a result, Felker said, "for 40 years, we were basically doing things based on clinical impressions, anecdotal experience, the way that a particular [doctor] was used to doing it. This is the first time we have high-quality data from a randomized controlled trial to help inform that decision."

For this study, 308 patients with acute decompensated heart failure were randomly divided into two groups. One was to receive furosemide (Lasix), the most commonly used diuretic for heart failure, intravenously by a bolus every 12 hours; the other would get it by continuous infusion, and both groups would get high and low doses.

Symptoms and measures of kidney function after 72 hours were about the same in each group.

But looking more closely at the data, the researchers found "a pretty strong suggestion that the high doses are actually better," said Felker, associate professor of medicine at Duke University Medical Center in Durham, N.C.

This goes against the grain of what people had been thinking: that high doses might be dangerous, he said. Also, many people had thought continuous administration was probably better but, Felker said, "the results were completely neutral. There was no difference."

"This study shows that as a general strategy, it is reasonable to use IV bolus dosing instead of continuous infusion dosing of furosemide for patients hospitalized with heart failure," said Dr. Stuart Katz, director of the Heart Failure Program at New York University Langone Medical Center in New York City.

"This is important because the continuous infusion is more expensive," he said. Also, the IV pole needed for the pump hampers the patient's ability to walk around, he noted.

But the study also showed that "the post-discharge event rates for patients hospitalized with heart failure is extremely high," Katz added. "Much more work is needed to develop effective strategies to reduce this risk."

An editorial accompanying the study echoed this sentiment. The trial "underscores the dismal prognosis for patients with acute decompensated heart failure," wrote Dr. Gregg Fonarow of the University of California at Los Angeles.

Fonarow commended the study for introducing the concept of comparative-effectiveness studies into the field of heart-failure research.

"In this well-conducted study, performed at institutions that have highly regarded programs for patients with heart failure, there was an unacceptably high (43%) rate of death, rehospitalization, or emergency department visits within the first 60 days, irrespective of treatment assignment," he said.

"Clearly, there is a crucial need to develop new agents and effective strategies for this patient population," he concluded.

More information

The American Heart Association has more on heart failure.