The goal of this clinical trial is to test the hypothesis that the continuation of empagliflozin during decongestive therapy in the setting of acute decompensated and hospitalized heart failure patients is not inferior compared to therapy cessation during the acute heart failure hospitalization. Randomized treatment (plus standard medical care) in patients with acute decompensated heart failure is one (1) tablet daily of empagliflozin 10 mg or matching placebo during the in-hospital stay (up to a maximum of 30 days), followed by treatment with empagliflozin 10 mg daily after discharge (but no later than day 31) until day 90. The primary outcome measure is the combined hierarchical endpoint of all-cause mortality, heart failure hospitalization and worsening renal function at 90 days after admission. Secondary outcome measures are the effects on urine output, diuretic efficiency, quality-of-life and the need for further administration of diuretics. Participants will * Take one tablet of study medication once daily (day 1 to day 90) * Restrict fluid intake to 1.5 liters of fluid per day and record the daily fluid intake for the study from day 1 to day 6 in the patient diary * Measure the urine output (day 1 to day 6) * Fill in Questionnaires (EQ-5D-3L (3-level version of the EuroQol five dimensional descriptive system), KCCQ-12 (Kansas City Cardiomyopathy Questionnaire comprising 12 items)) on day 0 (Baseline), at hospital discharge, and on day 30