Intravenous Iron to Treat Postoperative Anemia in Older Cardiac Surgery Patients

Inclusion Criteria: * Mentally competent with age ≥ 70 years * Elective AVR or CABG surgery * Expected uncomplicated postoperative trajectory, defined as: * No inotropic agents or ventilation at time of final inclusion (POD 1) * Expected discharge to general ward at POD 1 * Moderate postoperative IDA, defined as: * Hb between 85 and 110 g/L and * Ferritin \<100 µg/L or * Iron saturation (TSAT) \< 20% Exclusion Criteria: * Medical history of iron overload/haemochromatosis * Medical history of liver cirrhosis or ALT/AST value in blood serum triple of normal value (female patients: ALT \>120, AST \>105 U/L. Male patients: ALT\>150, AST\>135 U/L) * Severe renal failure (eGFR\<15ml/min/1.73m2) * Recent treatment with IVI (\<12 weeks prior) * Serious or severe allergic reaction to IVI in medical history * Severe asthma or eczema in medical history (atopic constitution)