Due to poor recruitment largely due to the covid pandemic, no safety concerns.

It is now recognized that iron deficiency in cardiovascular disease contributes to impaired clinical outcome.

The clinical trial is designed as a prospective, multi-centre, double-blind, randomised, controlled, interventional trial to investigate whether a therapy with i.v. iron (iron carboxymaltose) compared to saline can improve functional status across a subset of cardiovascular disease -namely acute myocardial infarction, atrial fibrillation, and heart failure with reduced ejection fraction.

Iron administration will be carried out according to summary of product characteristics. Bolus administration (1000 mg) will be followed by an optional administration of 500-1000 mg within the first 4 weeks (up to a total of 2000 mg which is in-label) according to approved dosing rules, followed by administration of 500 mg iron carboxymaltose (over 15 minutes), except when haemoglobin is > 16.0 g/dL or ferritin is > 600 µg/L.

Inclusion Criteria:

1. Cohort A (acute myocardial infarction): Acute Myocardial Infarction within 10 days (randomization/ first iron supplementation/ MRI must be performed within 10 days after AMI), without prior heart failure (defined as any known previous report of LVEF ≤ 45%) Cohort B (atrial fibrillation): Paroxysmal Atrial fibrillation or persistent AF Cohort C (heart failure): Left-ventricular ejection fraction ≤ 45 % (documented within the last 12 months prior to screening), all NYHA classes allowed
2. Confirmed presence of iron deficiency (ferritin < 100 ng/mL or ferritin 100 - 299 ng/mL with transferrin saturation < 20 %)
3. Haemoglobin ≤ 15.5 g/dL
4. Written informed consent

Exclusion Criteria:

1. Evidence of iron overload or disturbances in the utilisation of iron
2. History of severe asthma, eczema or other atopic allergy
3. History of immune or inflammatory conditions (e.g. systemic lupus erythematosus, rheumatoid arthritis)
4. Use of renal replacement therapy
5. Treatment with an erythropoietin stimulating agent (ESA), any i.v. iron and/or a blood transfusion in the previous 4 weeks prior to randomisation.