The primary objective of this study is to learn whether a morning dose of extended-release torsemide enhances renal sodium excretion after lunch (4-8 hours after dosing) compared to immediate-release torsemide. This is a randomized, double-blind, crossover study in patients with heart failure who are on a stable dose of a loop diuretic. During the study period, participants' current loop diuretics will be replaced with an equivalent dose of either immediate-release or extended-release torsemide. Following a one-week stabilization period on the assigned torsemide formulation, patients will report to the clinical site for an assessment visit. On the study day, patients will take a single dose of the same torsemide formulation they have been on for the past week, administered after breakfast. Urine samples be collected are: * 0-4 hours post-dosing (pre-lunch period) * 4-8 hours post-dosing (post-lunch period) * 8-24 hours post-dosing (24 hours period) The primary endpoint will be urinary sodium excretion (4-8 hours after dosing). This will be compared between the extended-release arm and the immediate-release arm to assess the efficacy of prolonged diuretic action. In addition, urinary potassium and creatinine excretion and creatinine clearance will be measured in all urine samples as the safety endpoints.