A Crossover Study of Patients With HF to Compare Natriuretic Effects of IR Torsemide vs. ER Torsemide Over 12 Hrs

A Crossover Study to Compare Natriuretic Effects of Extended Release Torsemide to Immediate Release Torsemide Over 12 Hours After Dosing in Patients With Heart Failure (EXTOR-HF)

This is a randomized double-blind crossover study of the patients with stable heart failure, who are taking a loop diuretic. During the study period, the participants' loop diuretics will be replaced by the equivalent dose of immediate release/extended release torsemide for one week. After a one week period, they will report to the site and will receive a single dose of either immediate release or extended release Torsemide. The sodium excretion will be measured for six hours after dosing and for an additional six hours after a high salt lunch.

The goal of this randomized double-blind crossover study is to assess whether extended release torsemide has a better efficacy than immediate release torsemide to induce renal sodium excretion after a salty lunch in patients with heart failure. The study will address if:

• the amounts of excreted sodium in the urine during the 2- and 6-hours' time period after a morning dose of extended release torsemide is different from the amounts after the immediate release torsemide.
• the amounts of excreted sodium in the urine during the 2- and 6-hours' time period after a salty lunch, which will be consumed approximately 6 hours following a morning dose of extended release torsemide, is different from the amounts after the immediate release torsemide.
• the amount of excreted sodium in the urine during the 24 hours' time period after a salty lunch, which will be consumed approximately 6 hours following a morning dose of extended release torsemide, is different from the amount after the immediate release torsemide.

Inclusion Criteria:

• Man or woman over the age of 18 years.
• Willing and able to sign the informed consent.
• A clinical diagnosis of chronic HF that is considered by patient's cardiologist/physician or an experienced clinician to be stable over the one-month period prior to randomization.
• Receiving oral furosemide (or equivalent doses of torsemide or bumetanide) for about 30 days prior to randomization.
• No anticipated changes in HF medications during the study period.
• Premenopausal women of child-bearing potential have a negative pregnancy test prior to beginning of the study and agree to use effective contraceptive methods during the study period

Exclusion Criteria:

• Requirement for a diuretic other than furosemide, bumetanide or torsemide except for spironolactone, eplerenone, finerenone, or SGLT2 inhibitors, at randomization and during the study.
• Myocardial infarction, stroke, transient ischemic attack, acute kidney injury or acute HF requiring admission to hospital within the last 30 days prior to randomization.
• Severe / symptomatic lung disease or respiratory symptoms distinct from HF.
• Urinary incontinence or inability to empty bladder.
• Uncontrolled diabetes mellitus or uncontrolled hypertension.
• Estimated GFR < 30 ml/min/1.72m2.
• History of flash pulmonary edema or amyloid cardiomyopathy.
• Female patients who are breastfeeding.