Effects of Acute and Chronic Empagliflozin Heart Failure

This is a 60-patient randomized, double-blind, placebo-controlled mechanistic study to understand the utility of empagliflozin in worsening heart failure (HF) patients with or without diabetes. Participants will be randomized to empagliflozin or placebo for 6 weeks, followed by a crossover of placebo patients to active therapy at 6 weeks-12 weeks.

Inclusion Criteria: * A clinical diagnosis of worsening heart failure (worsening of congestive symptoms with current therapies) in the opinion of the investigator. * A planned outpatient diuretic intervention (either up-titration of loop or addition of thiazide diuretic) for worsening heart failure per treating clinician. Diuretic intervention can occur via an unplanned in person visit (e.g., outpatient ambulatory clinic, emergency department, same day access visit) or via a telephone encounter (e.g., patient calling the clinic with reported weight gain and SOB that is prescribed uptitration of diuretic therapy). * Estimated or reported weight gain of at least 5 lbs. * Chronic daily oral loop diuretic dose ≥ 20mg furosemide equivalents for at least one month prior to enrollment * Estimated GFR (eGFR) ≥ 20 mL/min/1.73 m2 * Age ≥ 18 years old * Signed informed consent * English speaking participants only Exclusion Criteria: * Need for heart failure hospitalization at the time of randomization * Current use or plan to initiate renal replacement therapy * Significant bladder dysfunction or urinary incontinence * Inability to comply with the serial urine collection procedures * Chronic use of natriuretic doses of thiazide diuretics (≥50mg hydrochlorothiazide or equivalent) * Critical stenotic valvular disease, complex congenital heart disease or prior heart transplant * History of type 1 diabetes, diabetic ketoacidosis, "brittle" diabetes or frequent hypoglycemia or severe hypoglycemic episodes requiring emergent intervention (ER visit or EMS response, glucagon administration or forced oral carbs) in the last 6 months * History of or current urosepsis or frequent urinary tract infections * Anemia with hemoglobin \