Prospective Comparison of Metolazone Versus Chlorothiazide for Acute Decompensated Heart Failure With Diuretic Resistance

Inclusion Criteria: * Age \> 18 years old * Admitted for acute decompensated HF with left ventricular ejection fraction (LVEF) \<40% * Refractory fluid overload: * Unresponsive (\<500 mL net negative over previous 24 hours) AND ineffective diuresis (determined by HF team) to moderate intensity push or low intensity continuous infusion loop diuretic (80 mg IV furosemide or equivalent bumetanide dose of 4 mg) * English or Spanish-speaking subjects * Willing and able to comply with study procedures Exclusion Criteria: * Baseline thiazide use prior to admission or prior to study enrollment * Renal replacement therapies (RRT) or glomerular filtration rate (GFR) \<30 mL/min at the time of enrollment * Pregnant women * Cognitive impairment * Prisoners * Left ventricular assist devices (LVAD) or temporary mechanical circulatory support devices * History of cardiac transplant * Reported allergy to thiazides * No enteral access or unable to take medications enterally * Palliative diuretics * Systolic blood pressure (SBP) \<90 mm Hg prior to randomization * Patients receiving concomitant lithium therapy