Furosemide Plus Metolazone Boosts Natriuresis in Ambulatory Chronic Heart Failure Patients, finds study

The findings suggest that in patients with CHF who continue to experience congestion despite high doses of oral loop diuretics, refining the approach to intensifying diuretic therapy in outpatient settings may be necessary.

Heart failure, which affects millions worldwide, is characterized by fluid buildup that can lead to debilitating symptoms such as shortness of breath and fatigue. Diuretics are a cornerstone of treatment, helping to reduce fluid retention and alleviate symptoms. However, finding the optimal diuretic regimen tailored to individual patient needs remains a clinical challenge. There is insufficient evidence regarding the effectiveness and safety of diuretic treatments in ambulatory CHF patients who are resistant to conventional therapies for congestion.

To fill this knowledge gap, Aharon (Ronnie) Abbo, Heart Failure Unit, Department of Cardiology and the Rambam Health Care Campus, Haifa, Israel, and colleagues aimed to compare the safety and potency of commonly used diuretic regimens in CHF patients.

For this purpose, the researchers conducted a prospective, randomized, open-label, crossover study in NYHA class II-IV CHF patients treated in an ambulatory day-care unit. A total of 42 patients were recruited. Each participant underwent three distinct diuretic protocols: intravenous (IV) furosemide at 250mg alone; IV furosemide at 250mg combined with oral metolazone at 5mg; and IV furosemide at 250mg along with IV acetazolamide at 500mg. These treatments were administered once weekly, following one of six randomly assigned sequences.

The primary outcome measured was total sodium excretion, with total urinary volume excreted over six hours post-treatment initiation as a secondary endpoint.

The study revealed the following findings:

• Administration of furosemide plus metolazone resulted in the highest weight of sodium excreted, 4691 mg compared to furosemide alone 3835 mg, and to furosemide plus acetazolamide 3584 mg.
• Furosemide plus metolazone resulted in 1.84 liters of urine, compared to 1.58 liters collected following administration of furosemide plus acetazolamide and 1.71 liters following furosemide alone.
• The incidence of worsening renal function (WRF) was significantly higher when adding metolazone (41%) to furosemide compared to furosemide alone (17%) and to furosemide plus acetazolamide (2.6%).

The researchers noted the potential for residual effects from previous treatments, although they did not observe statistically significant evidence of this phenomenon. Additionally, given that DEA-HF was conducted at a single center, its applicability to broader settings is constrained. The authors cautioned that attempting to replicate the study as a multicenter trial would be impractical.

Reference:

Abbo A, et al "Diuresis efficacy in ambulatory congested heart failure patients: intrapatient comparison of 3 diuretic regimens (DEA-HF)" JACC Heart Fail 2024; DOI: 10.1016/j.jchf.2024.04.014.