On-Treatment Analysis of Torsemide Versus Furosemide for Patients Hospitalized for Heart Failure: A Post-Hoc Analysis of TRANSFORM-HF

AIM: The TRANSFORM-HF trial demonstrated no significant outcome differences between torsemide and furosemide following hospitalization for heart failure (HF), but may have been impacted by non-adherence to the randomized diuretic. The current study sought to determine the treatment effect of torsemide versus furosemide using an on-treatment analysis inclusive of all randomized patients except those confirmed non-adherent to study diuretic. METHODS AND RESULTS: TRANSFORM-HF was an open-label, pragmatic randomized trial of 2859 patients hospitalized for HF from June 2018 through March 2022. Patients were randomized to a loop diuretic strategy of torsemide versus furosemide with investigator-selected dosage. This post-hoc on-treatment analysis included all patients alive with either known or unknown diuretic status, and excluded patients confirmed to be non-adherent to study diuretic. This modified on-treatment definition was applied separately at time of hospital discharge and 30-day follow-up. All-cause mortality and hospitalization outcomes were assessed over 12 months. Overall, 2570 (89.9%) and 2374 (83.0%) patients were included in on-treatment analyses at discharge and 30-day follow-up, respectively. There was no significant difference in all-cause mortality between torsemide and furosemide in patients on-treatment at discharge (17.5% vs. 17.8%; hazard ratio [HR] 1.01 [95% confidence interval [CI] 0.83-1.22], p = 0.96) and at 30-day follow-up (14.5% vs. 15.0%; HR 1.02 [95% CI 0.81-1.27], p = 0.90). All-cause mortality or all-cause hospitalization was similar between torsemide and furosemide in patients who were on-treatment at discharge (58.3% vs. 61.3%; HR 0.92 [95% CI 0.82-1.03]) and 30-day follow-up (60.9% vs. 64.4%; HR 0.93 [95% CI 0.82-1.05]). In patients who were on-treatment at 30-day follow-up, there were 677 total hospitalizations in the torsemide group and 686 total hospitalizations in the furosemide group (rate ratio 0.99 [95% CI 0.86-1.14], p = 0.87). CONCLUSIONS: In TRANSFORM-HF, a post-hoc on-treatment analysis did not meaningfully differ from the original trial results. Among those deemed compliant with the assigned diuretic, there remained no significant difference in mortality or hospitalization after HF hospitalization with a strategy of torsemide versus furosemide. CLINICAL TRAIL REGISTRATION: ClinicalTrials.gov Identifier: NCT03296813.