This study evaluates the efficacy and safety of single dose preoperative ferric carboxymaltose in the prevention of postoperative infections and blood transfusions in patients scheduled for cardiac surgery. Half of the patients will receive ferric carboxymaltose and half of the patients physiological saline solution as placebo.

Inclusion criteria:

1. Patients presenting with cardiac disease requiring surgical operation

2. Open heart surgery is considered the best appropriate treatment strategy according to the current guidelines.

   • significant three vessel disease
   • left main disease ± single, two or three vessel disease
   • two-vessel disease with proximal LAD stenosis
   • coronary artery disease requiring revascularization not amenable to percutaneous coronary intervention
   • Aortic valve disease requiring aortic valve surgery
   • Mitral valve disease requiring surgical mitral surgery
   • Combined surgery for revascularization and valve disease
   • surgery of ascending aorta

3. Have provided signed written informed consent

Exclusion Criteria:

1. Age < 35 years
2. Patients requiring , emergency or salvage cardiac surgical operation
3. Participation in another clinical study or treatment with another investigational product 30 days prior to randomization
4. Moribund patient not expected to survive surgery 12 months after surgery
5. Active malignant disease with a short life expectancy, not eligible for surgery
6. Hemoglobin levels > 155 g/dL for women and >167 g/dl for men (upper reference limits for TYKSlab)
7. Ferritin levels >150 ug/l for women and >400 ug/l for men.
8. Renal dialysis therapy for chronic renal failure or severe preoperative renal impairment (eGFR<30ml/min).
9. Study treatment can't be infused during the required time window: minimum 48 hours and maximum 21 days before the operation.
10. Ongoing oral or parenteral iron medication at the time of randomization
11. Iron or haemoglobin metabolism or synthesis disorders
12. Primary or secondary hemochromatosis (in males and postmenopausal females, a serum ferritin value of over 300 ng/mL (670 pmol/L); and in premenopausal females, a serum ferritin value of over 150[17] or 200[18] ng/mL (330 or 440 pmol/L) indicates iron overload).
13. Porphyria cutanea tarda.
14. Liver failure (Child-Pugh class B or C).
15. Pregnancy.
16. Body weight less than 50kg.
17. Ongoing antibiotic treatment other than prophylactic urine tract infection antibiotics.

Double blinding, study drug administration by separate staff blinded from participant and investigators