Short Term Oral Iron Supplementation in Systolic Heart Failure Patients Suffering From Iron Deficiency Anemia

Inclusion Criteria: * Age ≥ 18 year old * Systolic heart failure patients without clinical sign of decompensation at outpatient clinic * New York Heart Association (NYHA) functional class II-III able to perform 6MWT * LVEF \< 50% * On heart failure therapy * Haemoglobin (Hb) \< 13 gr/dL (male); Hb \< 12 gr/dL (female) and \> 8 gr/dL * Ferritin \< 100 µg/L or Ferritin 100-300 µg/L dengan Transferrin saturation (Tsat) \< 20% * Agree to participate Exclusion Criteria: * History of : active bleeding,infection, malignancy, haematological abnormality, peptic ulcer * History of myocardial revascularization (CABG/PCI) within 3 month * Acute Coronary Syndrome (ACS), stroke,Transient Ischemic Attack (TIA) within 3 month * Know to have allergic reaction to Ferrous sulfate * History of intravenous iron administration within 1 month * Permanent Pace Maker(PPM)/Implantable Cardiac Defibrillator (ICD)/Cardiac Resynchronization Therapy (CRT) * estimated Glomerular Filtration Rate (eGFR) \< 30 ml/min/1.73m2 * NT-proBNP \> 4000 pg/ml (for patients without baseline data) or decreased level of NT-proBNP \< 30% from baseline * Increase level of serum alanine aminotransferase (ALT)/ serum aspartate aminotransferase (AST)\> 3x normal value * Moderate to severe primary valvular heart disease * Congenital heart disease * Right heart failure due to primary pulmonary hypertension, cor pulmonale, Chronic Thrombo-Embolic Pulmonary Hypertension (CTEPH)