Torsemide vs Furosemide Among Patients With New-Onset vs Worsening Chronic Heart Failure: A Substudy of the TRANSFORM-HF Randomized Clinical Trial.

Importance: Differences in clinical profiles, outcomes, and diuretic treatment effects may exist between patients with de novo heart failure (HF) and worsening chronic HF (WHF).

Objectives: To compare clinical characteristics and treatment outcomes of torsemide vs furosemide in patients hospitalized with de novo HF vs WHF.

Design, Setting, And Participants: All patients with a documented ejection fraction who were randomized in the Torsemide Comparison With Furosemide for Management of Heart Failure (TRANSFORM-HF) trial, conducted from June 18 through March 2022, were included in this post hoc analysis. Study data were analyzed March to May 2023.

Exposure: Patients were categorized by HF type and further divided by loop diuretic strategy.

Main Outcomes And Measures: End points included all-cause mortality and hospitalization outcomes over 12 months, as well as change from baseline in the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS).

Results: Among 2858 patients (mean [SD] age, 64.5 [14.0] years; 1803 male [63.1%]), 838 patients (29.3%) had de novo HF, and 2020 patients (70.7%) had WHF. Patients with de novo HF were younger (mean [SD] age, 60.6 [14.5] years vs 66.1 [13.5] years), had a higher glomerular filtration rate (mean [SD], 68.6 [24.9] vs 57.0 [24.0]), lower levels of natriuretic peptides (median [IQR], brain-type natriuretic peptide, 855.0 [423.0-1555.0] pg/mL vs 1022.0 [500.0-1927.0] pg/mL), and tended to be discharged on lower doses of loop diuretic (mean [SD], 50.3 [46.2] mg vs 63.8 [52.4] mg). De novo HF was associated with lower all-cause mortality at 12 months (de novo, 65 of 838 [9.1%] vs WHF, 408 of 2020 [25.4%]; adjusted hazard ratio [aHR], 0.50; 95% CI, 0.38-0.66; P < .001). Similarly, lower all-cause first rehospitalization at 12 months and greater improvement from baseline in KCCQ-CSS at 12 months were noted among patients with de novo HF (median [IQR]: de novo, 29.94 [27.35-32.54] vs WHF, 23.68 [21.62-25.74]; adjusted estimated difference in means: 6.26; 95% CI, 3.72-8.81; P < .001). There was no significant difference in mortality with torsemide vs furosemide in either de novo (No. of events [rate per 100 patient-years]: torsemide, 27 [7.4%] vs furosemide, 38 [10.9%]; aHR, 0.70; 95% CI, 0.40-1.14; P = .15) or WHF (torsemide 212 [26.8%] vs furosemide, 196 [24.0%]; aHR, 1.08; 95% CI, 0.89-1.32; P = .42; P for interaction = .10), In addition, no significant differences in hospitalizations, first all-cause hospitalization, or total hospitalizations at 12 months were noted with a strategy of torsemide vs furosemide in either de novo HF or WHF.

Conclusions And Relevance: Among patients discharged after hospitalization for HF, de novo HF was associated with better clinical and patient-reported outcomes when compared with WHF. Regardless of HF type, there was no significant difference between torsemide and furosemide with respect to 12-month clinical or patient-reported outcomes.