Heart failure treatment questioned

Over five million Americans suffer annually from heart failure — one of the most common causes of hospitalization and readmission — yet the medication most often prescribed may not be the most effective.

Heart failure is typically treated by loop diuretics, commonly known as water pills, which stimulate the kidneys to excrete excess salt and water to relieve fluid that builds up due to heart complications. Researchers at the Yale School of Medicine have found that of three loop diuretics on the market, the one that may be the most beneficial to patients is prescribed by hospitals in less than 1 percent of cases, said lead author Behnood Bikdeli, an internal medicine and cardiology postdoctorate at the medical school. The study was issued online on April 1 and will be published in today’s print issue of the Journal of American Cardiology.

Bikdeli said these three medications — furosemide, bumetanide and torsemide — have been available for over 10 years, but nobody has conducted research to investigate potential differences between them and determine the most effective treatment. He and his team reviewed existing literature and data from hospitals, reporting that although 87 percent of heart failure patients take furosemide, they might be better off taking torsemide.

Still, Bikdeli said he would not recommend a change in medical practice without follow-up studies to see if torsemide is actually the best option.

“The existing literature is so limited that our meta analysis was also somewhat limited, but what we’re observing is a signal that torsemide might be a better diuretic with a more predictable effect than furosemide,” Bikdeli said.

A “definitive answer” to which loop diuretic is the most beneficial would require a double blind, randomized trial comparing parameters such as death, hospital readmission and quality of life for patients who take torsemide and patients who take furosemide, he added.

Bikdeli’s report is an indication of the lack of proper “head-to-head studies” of different heart failure treatments, said cardiology professor Harlan Krumholz, who also worked on the research. Krumholz added that he hopes this paper will be a catalyst for more research investigating loop diuretics — a common class of medications that he said has not been studied enough.

The widespread use of furosemide is based on habit rather than on scientific evidence that it is the more beneficial treatment, Krumholz said, adding that he does not know why furosemide became so popular since all three diuretics are relatively cheap to produce.

“The implication here is less of a conclusion and more of a teaser pointing out the gaps in current research,” Krumholz said.

But Yale cardiology affiliate Kumar Dharmarajan, another member of the research team, said there are biological reasons to believe that torsemide may be more effective than furosemide. Torsemide is more “orally bio-available,” he said, which means that it is more efficiently absorbed in the intestines. Torsemide also lasts longer in the body, so it has more time to aid the kidneys in relieving fluid build-up, he added.

With these distinctions in mind, Dharmarajan said he also hopes that in the near future the different diuretics will be studied through a randomized, controlled experiment. He added that observational studies will not be sufficient in determining which medication is optimal, since so few hospitals are prescribing torsemide in the first place.

The researchers obtained data on heart failure hospitalizations through the database Premier Inc.

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