The study is designed to be a prospective, randomized study is to compare the effectiveness of two standard of care loop diuretics (furosemide versus torsemide) on clinical outcomes among patients currently on a stable dose of loop diuretics.

This study will be a randomized, unblinded, two-arm, multi-center clinical trial of patients receiving loop diuretics for treatment of heart failure in an outpatient clinic. This study will serve as additional enrollment for Cardio-Renal Effects of Torsemide vs. Furosemide: A TRANSFORMHF Mechanistic Sub-Study (HIC 2000025867) which is currently only enrolling patients admitted to the hospital for worsening heart failure. Thus allowing for expanded enrollment into HIC 2000025867 with a more diverse group of heart failure patients. Participants will be co-enrolled into this study and HIC 2000025867, NCT03296813.

Patients will be randomized 1:1 to either oral torsemide OR oral furosemide (dosing at discretion of local provider with dose equivalency guidance provided). This study will include stable subjects seen at the outpatient setting. The initial and follow-up dosing of torsemide and furosemide will be at healthcare provider discretion, with the following conversion provided as a guide: 1 mg torsemide to 2-4 mg oral furosemide. For instance, a patient would receive torsemide 20mg or furosemide 40-80 mg. Providers will be asked to document their planned initial dose and dosing frequency of torsemide and furosemide Randomization will occur within thirty days after the consent process and at the discretion of the healthcare provider and research team. Following randomization, the study medication is expected to constitute the oral diuretic therapy for one year. Patients will be prescribed the randomized study medication on the day of randomization.

Dose adjustments will be at the discretion of the treating healthcare provider(s) with strategies in place to maintain prescription of and adherence to the randomized medication. All patients will have 30-day, and 12-month post-randomization phone contacts for assessment of vital status, interval hospitalizations, concomitant HF medications, adherence, and weight.

To achieve these goals, the investigators propose a multi-center 125-patient study that will also co-enroll into Transform Ancillary (HIC 2000025867, NCT03296813) a mechanistic sub-study of this study and TRANSFORMHF.

Inclusion Criteria:

1. Patients with a diagnosis of heart failure and who have been on a stable dose of a diuretic for at least 30 days.
2. Plan for a daily outpatient oral loop diuretic regimen with anticipated need for long term loop diuretic use
3. ≥ 18 years of age
4. Signed informed consent

Exclusion Criteria:

1. End-stage renal disease requiring dialysis therapy
2. Inability or unwillingness to comply with the study requirements
3. History of heart transplant or actively listed for heart transplant
4. Implanted left ventricular assist device or implant anticipated <3 months
5. Pregnant or nursing women or women who are trying to conceive
6. Malignancy or other non-cardiac condition limiting life expectancy to <12 months
7. Known hypersensitivity to furosemide, torsemide, or related agents

one year