Protocolised Natriuresis-Guided Decongestion at Different Diuretic Intensities in Acute Heart Failure

The goal of this clinical trial is to learn how different doses of a water-removing medicine (diuretic) work in adults admitted to hospital with acute heart failure. It will also assess the safety of these treatment approaches. The main questions this study aims to answer are: Does starting with a higher or lower dose of diuretic affect how much sodium and urine the body removes during the first 24 hours? Are there differences in side effects or short-term health outcomes between the treatment approaches? Researchers will compare two treatment approaches that use urine sodium and urine output to guide diuretic treatment with standard care. Participants will receive intravenous diuretic treatment and have their urine sodium, urine output, symptoms, blood tests, and clinical outcomes assessed.

Inclusion Criteria: * Age 18 years or older * Malaysian nationality * Hospitalised with acute heart failure, either de novo acute heart failure or acute decompensated chronic heart failure * Clinical evidence of congestion requiring intravenous loop diuretic therapy, with at least one of the following: peripheral oedema, orthopnoea, paroxysmal nocturnal dyspnoea, pulmonary crepitations, elevated jugular venous pressure, ascites, or congestive hepatomegaly * Able to provide informed consent Exclusion Criteria: * End-stage renal disease requiring chronic dialysis * Requirement or anticipated requirement for invasive mechanical ventilation * Requirement or anticipated requirement for inotropic or vasopressor support * Requirement or anticipated requirement for renal replacement therapy * Cardiogenic shock or systolic blood pressure below 100 mmHg * Pregnancy or breastfeeding * Known hypersensitivity to furosemide