Natriuresis-guided Depletion After Cardiac Surgery

Inclusion Criteria: * Adult patient (age \> 18 years) * Scheduled for cardiac surgery, including mitral valve repair or replacement, aortic valve replacement, coronary artery bypass grafting (CABG), ascending aortic repair, or combined procedures * Undergoing surgery with cardiopulmonary bypass (CPB) * Eligible to receive intravenous furosemide for fluid overload within 48 hours following surgery, as prescribed by the referring physician * Written and oral informed consent obtained * Covered by the French national health insurance (Sécurité Sociale) Exclusion Criteria: * Aortic arch repair requiring deep hypothermic circulatory arrest * Active endocarditis * Hemodynamic instability requiring vasopressor or inotropic support (norepinephrine, dobutamine, epinephrine, or vasopressin) * Failure to wean from CPB requiring mechanical circulatory support * Chronic kidney disease with an estimated glomerular filtration rate (eGFR) \< 60 mL/min * Chronic use of loop diuretics * Known allergy to furosemide * Active postoperative bleeding and/or reoperation for bleeding * Participation in another interventional study that may affect the primary outcome measure * Patient deprived of liberty by administrative or judicial decision, or placed under legal protection (guardianship or curatorship)