Impact of baseline kidney dysfunction on oral diuretic efficacy following hospitalization for heart failure - insights from TRANSFORM-HF.

Aim: Among patients discharged after hospitalization for heart failure (HF), a strategy of torsemide versus furosemide showed no difference in all-cause mortality or hospitalization. Clinicians have traditionally favoured torsemide in the setting of kidney dysfunction due to better oral bioavailability and longer half-life, but direct supportive evidence is lacking.

Methods And Results: 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 (without dialysis). In this post-hoc analysis, baseline renal function during the index hospitalization was assessed as categories of estimated glomerular filtration rate (eGFR; <30, 30-<60, ≥60 ml/min/1.73 m). The interaction between baseline renal function and treatment effect of torsemide versus furosemide was assessed with respect to mortality and hospitalization outcomes, and the change in Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS). Of 2859 patients randomized, 336 (11.8%) had eGFR <30 ml/min/1.73 m, 1138 (39.8%) had eGFR 30-<60 ml/min/1.73 m, and 1385 (48.4%) had eGFR ≥60 ml/min/1.73 m. Baseline eGFR did not modify treatment effects of torsemide versus furosemide on all adverse clinical outcomes including individual components or composites of all-cause mortality and all-cause (re)-hospitalizations, both when assessing eGFR categorically or continuously (p-value for interaction all >0.108). Similarly, no treatment effect modification by eGFR was found for the change in KCCQ-CSS (p-value for interaction all >0.052) when assessing eGFR categorically or continuously.

Conclusion: Among patients discharged after hospitalization for HF, there was no significant difference in clinical and patient-reported outcomes between torsemide and furosemide, irrespective of renal function.