Abstract 14756: The Effect of Torsemide vs Furosemide Across the Renal Function Spectrum - Insights From the TRANSFORM-HF Trial

Abstract

Introduction: Among patients discharged after hospitalization for heart failure (HF), a strategy of torsemide versus furosemide showed no difference in all-cause mortality or hospitalization. Hypothesis: Clinicians may favor torsemide in the setting of renal dysfunction due to better oral bioavailability and longer half-life. However, the impact of baseline renal function on these findings is unknown. Methods: The TRANSFORM-HF trial randomized patients hospitalized for HF to a long-term strategy of torsemide versus furosemide, and enrolled patients across the spectrum of renal function excluding patients on dialysis. In this post-hoc analysis, baseline renal function during the index hospitalization was assessed as tertiles of estimated glomerular filtration rate (eGFR) (using 2021 CKD EPI formula), blood urea nitrogen (BUN), and BUN/creatinine ratio. The interaction between baseline renal function and treatment effect of torsemide vs furosemide was assessed for endpoints of (1) all-cause mortality and (2) all-cause mortality and all-cause readmissions at 12 months. Results: Of 2859 patients randomized, 336 (11.7%) had eGFR<30ml/min/1.73m 2 , 1138 (39.8%) had eGFR 30-60 ml/min/1.73m 2 , and 1385 (48%) had eGFR≥60ml/min/1.73m 2 . Baseline eGFR and BUN did not clearly modify the treatment effect of torsemide vs furosemide for either all-cause mortality (Figure, Panel A) or all-cause mortality and all-cause readmissions at 12 months (Figure, Panel B) . For the composite outcome, BUN/creatinine ratio showed evidence of heterogeneity of treatment effect potentially in favor of torsemide in the middle tertile (interaction p-value<0.01). Conclusion: Across the spectrum of baseline eGFR and BUN, a strategy of torsemide versus furosemide did not significantly impact mortality or readmission outcomes following hospitalization for HF..