Diuretic dosing and outcomes with torsemide and furosemide following hospitalization for heart failure: The TRANSFORM-HF trial.

Aims: The TRANSFORM-HF trial found no difference in clinical outcomes between torsemide versus furosemide after hospitalization for heart failure. This analysis aimed to assess the impact of diuretic dosing on the primary and secondary clinical outcomes.

Methods and results: This post-hoc analysis of TRANSFORM-HF categorized patients into three groups by discharge diuretic dose: (1) ≤40 mg, (2) >40-80 mg, and (3) >80 mg of furosemide equivalents. The associations between discharge dose and 12-month clinical events, and change in Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS), were assessed. Overall, 2379 patients were included, aged 65 years (interquartile range 56-75), 883 (37.1%) women, and 812 (34.2%) Black. Furosemide had adjusted hazard ratios (aHR) for all-cause mortality of 1.21 (95% confidence interval [CI] 0.91-1.59) for discharge dose group 2 and 1.40 (95% CI 1.04-1.88) for group 3, compared with group 1. For torsemide, aHRs were 1.74 (95% CI 1.32-2.30) for group 2 and 1.58 (95% CI 1.14-2.19) for group 3. No evidence of heterogeneity for the association between increased mortality and higher dose was found by loop diuretic type (p_interaction = 0.17). Higher doses of furosemide and torsemide were associated with increased risk of all-cause hospitalization and the composite of all-cause mortality and hospitalization, without evidence of heterogeneity by loop diuretic type (p_interaction > 0.2). Changes in KCCQ-CSS from baseline at 12 months was similar across dose groups for both drugs.

Conclusion: Following hospitalization for heart failure, higher loop diuretic dosing was independently associated with worse clinical and patient-reported outcomes. The correlation between higher loop diuretic dose and outcomes was consistent, regardless of loop diuretic used.