Comparative analysis of furosemide and torsemide efficacy in 24 hours of acute heart failure admission

Abstract

Background: Intravenous (IV) furosemide and torsemide represent a cornerstone of guideline-directed medical therapy for acute heart failure (AHF). However, the evidence regarding the superiority of each agent remains controversial.

Methods: The prospective, open-label, comparative study included 51 adult patients hospitalized due to AHF. Torsemide was administered to 25 patients (49%), and furosemide to 26 patients (51%). The primary endpoint was the change in urinary spot sodium level at 24 h, used to assess diuretic efficacy. Secondary outcomes included lung ultrasound (LUS) B-lines, clinical status evaluation based on the Borg scale, Killip-Kimball classification, and daily urine output.

Results: After 24 h of treatment, urinary sodium levels increased by an estimated marginal mean (EMM) of 21.84 mmol/L in the furosemide group and 0.97 mmol/L in the torsemide group (p = 0.173). The number of B-lines over 24 h decreased, with an EMM of 28.31 in the furosemide group, and 30.12 in the torsemide group (p = 0.779). The severity of dyspnea, measured by the Borg scale, decreased over 24 h with an EMM of 3.58 points in the furosemide group, and 3.62 points in the torsemide group (p = 0.891). Pulmonary congestion, measured by the Killip-Kimball classification, minimized with an EMM of 0.42 points in the furosemide group, and 0.47 points in the torsemide group (p = 0.770). Daily urine output after 24 h of treatment reached an EMM of 3,559.67 mL in the furosemide group, and 2,734.89 mL in the torsemide group (p = 0.068).

Conclusion: Both furosemide and torsemide demonstrated comparable efficacy in the initial treatment of AHF, as assessed by laboratory, ultrasound, and clinical parameters.

Keywords: B-lines; acute heart failure; furosemide; loop diuretics; torsemide; urinary sodium.

FIGURE 1

The increase in spot urinary sodium levels, the decrease in the number of B-lines, as well as in the Borg scale and Killip-Kimball classification, along with the volume of daily urine output in the total cohort during the first 24 h of treatment. The values are presented as estimated marginal means ± SE, standard error. The modified Borg Dyspnea Scale assesses ratings of perceived shortness of breath from 0 (nothing at all) to 10 (maximum); the Killip-Kimball classification assesses the severity of heart failure: 1) no clinical signs, 2) mild pulmonary edema, 3) severe pulmonary edema, 4) cardiogenic shock.

FIGURE 2

(A) The decrease in the number of B-lines across subgroups during the first 24 h of treatment. (B) The volume of daily urine output across subgroups during the first 24 h of treatment. The values are presented as estimated marginal means. Abbreviations: SE, standard error; AF, atrial fibrillation; COPD, chronic obstructive pulmonary disease; eGFR, estimated glomerular filtration rate (mL/min/1.73 m²); BMI, body mass index (kg/m²), HFpEF, heart failure with preserved ejection fraction; HFmEF, heart failure with mildly reduced ejection fraction.