Effect of Acetazolamide on Diuresis and Natriuresis in Patients With Acute Heart Failure (SANDI STUDY)

Inclusion Criteria: * Patients admitted for acute heart failure and ≥ 1 clinical sign of volume overload (edema, ascites, or pleural effusion). * NTproBNP levels \>1000 pg/mL or BNP \>250 ng/mL on admission. * Under treatment with furosemide and iSGLT2 according to European guidelines and indication of association of another diuretic due to residual congestion data defined by ADVOR SCORE\>1. Exclusion Criteria: * Systolic blood pressure \<90 mmHg or mean arterial pressure \< 65 mmHg. * Maintenance treatment with acetazolamide/ Treatment with acetazolamide in the month prior to inclusion in the study. * Anticipated need for intravenous inotropes, vasopressors or nitroprusside during the study. * Contraindication to ISGLT2. * Type 1 diabetes mellitus * GFR \< 20 ml/min/m2 or renal replacement therapy/ultrafiltration at any time prior to the study. * Anticipated exposure to nephrotoxic agents, such as iodinated contrast during admission. * Concurrent diagnosis of acute coronary syndrome. * History of congenital heart disease requiring surgical correction. * History of cardiac transplantation and/or ventricular assist device. * Pregnant or breastfeeding patients. * Inability to adequately collect diuresis. * Serum potassium less than 3.5 mEq/L. * Venous pH \<7.30 * Severe aortic stenosis or obstructive hypertrophic cardiomyopathy. * Sulfonamide allergy, liver cirrhosis, renal lithiasis.