 The study will be a prospective, open-label, randomized cohort study comparing adding high-dose spironolactone to usual heart failure care versus usual care in patients with acute decompensated heart failure. Patients will be randomized in a 1:1 fashion to either usual care or high-dose spironolactone plus usual care. Both arms of the study will continue with treatment of ADHF until euvolemia as defined as the resolution of pulmonary edema, peripheral edema, abdominal bloating andor jugular venous distention. Assessment of clinical status, urine and serum electrolytes, symptoms and renal function will be performed in accordance to standard of care. 