Acetazolamide or Metolazone in Acute Heart Failure

Acetazolamide 250mg orally per day plus furosemide as per protocol. The intervention is administered on the day of hospital admission and for two consecutive mornings. The total intervention consists of 3 doses. The intervention is discontinued on the third morning. The calculation of the congestion score is performed every morning until the third morning. If complete decongestion is achieved, the primary outcome will be considered fulfilled.

Metolazone 2.5mg orally per day plus furosemide as per protocol. The intervention is administered on the day of hospital admission and for two consecutive mornings. The total intervention consists of 3 doses. The intervention is discontinued on the third morning. The calculation of the congestion score is performed every morning until the third morning. If complete decongestion is achieved, the primary outcome will be considered fulfilled.

Intravenous furosemide in a double daily dose. The dosage is determined by a predefined table based on the admission renal function and the outpatient dose prior to admission. In general terms, for patients with an estimated glomerular filtration rate above 60 ml/min/1.73m² or those experiencing heart failure debut, the dose will be 1x the outpatient dose. For those with a glomerular filtration rate below 60 ml/min/1.73m², the dose will be 2x the outpatient dose. The dosing protocol for this arm also serves as guidance for furosemide in the intervention arms.