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  • A clinical trial funded by the National Institute of Health (NIH) revealed there is no significant difference in the effectiveness of furosemide and torsemide, two heart failure drugs, when it comes to patient survival times.
  • Despite furosemide being the loop diuretic that is most frequently used in heart failure patients, some studies had indicated that torsemide may be more effective.
  • Now, this new trial, which is one of the biggest investigations of common medications for heart failure, tries to settle the debate about which drug is better for patients with heart failure who face a heightened risk of mortality.

Heart failure is when the heart struggles to pump sufficient blood throughout the body.

There are currently more than 6 million adults in the United States who have heart failure, as reported by the Centers for Disease Control and Prevention (CDC).

That number is expected to rise to more than 8 million by 2030.

Previous research has shown that the medication torsemide potentially had an edge over furosemide in decreasing heart failure-related fatalities, but this issue had yet to be definitively settled.

Now, results from a new clinical trial not only offer immediate clinical implications but also emphasize the urgent need for more effective, life-saving treatments for people with heart failure.

Funded by the National Heart, Lung, and Blood Institute (NHLBI) within NIH, the study has been published in the Journal of the American Medical Association (JAMA).

As diuretics or “water pills,” both torsemide and furosemide help alleviate congestion and respiratory issues caused by fluid accumulation.

Furosemide, discovered decades ago, remains the most commonly prescribed diuretic for heart failure treatment, while torsemide is a relatively newer medication.

In the study, scientists looked at 2,859 people who were admitted to hospitals for heart failure at 60 different medical centers throughout the United States.

The researchers randomly placed these patients on either furosemide or torsemide treatment plans and monitored them for up to 30 months to observe their survival rates.

The study participants’ average age was 65 years old. During the follow-up, 26% of those taking torsemide and another 26% of those on furosemide died, showing nearly identical outcomes between the two treatments.

In summary, researchers said the study demonstrated that torsemide did not enhance survival rates in comparison to furosemide for the high-risk group of heart failure patients, and the hospitalization rates for both medications were also found to be similar.

Nearly 37% were women and nearly 34% were Black Americans, populations that are frequently underrepresented in heart failure clinical research.

Dr. Robert Mentz, a cardiologist and an associate professor of medicine at Duke University Medical Center in North Carolina as well as lead author of the study, explained the key findings to Medical News Today.

“We found that there was no difference in clinical outcomes when patients with heart failure and a recent hospitalization were treated with a loop diuretic strategy of furosemide versus torsemide (i.e., different water pills),” he said.

Clinicians routinely spend time switching between these loop diuretics. These data emphasize that clinicians could better spend that time working to get patients on the right dose of loop diuretic and then also focus on adjusting (i.e., starting and titrating) other medications with known clinical benefits in patients with heart failure

Dr. Robert Mentz

Mentz noted there are limitations to the study, telling MNT that “this was a pragmatic trial which meant that it was embedded in routine clinical care and worked to minimize the burden on enrolling sites and patients.”

“While this supported the generalizability of the study (i.e., the ability to apply to patients in usual care), we did have higher rates of cross-over between study arms, which may have limited the ability to detect a difference between these medications,” Mentz explained.

Ragavendra Baliga, MBBS, a specialist in advanced heart failure and a professor of internal medicine at The Ohio State University Wexner Medical Center who was not involved in this study, agreed.

“This study’s aim was to demonstrate that torsemide therapy would reduce mortality, but unfortunately the study was limited by loss to follow up, non-adherence and crossover,” she told MNT.

Limitations of this research include that many patients with heart failure also have kidney failure and other limitations discussed by study authors including the fact that it had an open-label design, sample size was approximately half of what was originally intended, patients’ withdrawals were higher than other heart failure trials, imprecise all-cause outcomes, crossovers during follow up and diuretic discontinuation.

Ragavendra Baliga

Dr. Richard Wright, a cardiologist at Providence Saint John’s Health Center in Cal/ifornia who also wasn’t involved in the study, told MNT that “this trial, although creating a stir, did not change my practice one bit – for the simple reason that clinicians prescribe loop diuretics to induce diuresis, not to reduce death (although a laudatory goal, no loop diuretic has been shown to have a beneficial effect on long term mortality).”

Torsemide has been used by experienced heart failure clinicians because the drug, particularly when used at “appropriate” and at times high doses, can induce diuresis in patients who manifest an inadequate diuretic response to conventional doses of oral furosemide. I would not expect that either drug would be superior for a mortality endpoint, and indeed this trial confirmed that expectation. The trial just looked at the wrong endpoint.

Dr. Richard Wright

Baliga noted that “this study is important because it suggests that future studies in heart failure should include factors such as renal dysfunction, non-adherence, dose titration, time-varying factors and inclusion of patients of multi-ethnicity particularly Hispanics.”

Although research has found that some medications can improve results for people with heart failure, experts say it’s crucial to note that adopting a heart-healthy lifestyle can help reduce the likelihood of developing the disease in the first place.

This includes maintaining a healthy weight, exercising regularly, quitting smoking, getting enough sleep, and managing stress. Additionally, controlling risk factors, like diabetes and high blood pressure, is essential.

But ultimately, experts say more work is needed to make sure that heart failure treatments are applied in a consistent manner, based on current evidence.