This study will address whether the additional use of Intravenous (IV) iron on top of standard care will improve the outlook for patients with heart failure and iron deficiency. One group of participants will receive treatment with iron injections and the other group will not receive any iron injections.

Chronic heart failure (CHF) is a very common medical problem. Despite improvements in treatment, many patients suffer limiting symptoms of shortness of breath and fatigue. Hospitalisation for CHF is common and life expectancy reduced. Many patients with CHF have a deficiency of iron (low iron levels or cannot use iron properly), and this is associated with poorer outcomes. Some small research studies have suggested that giving patients intravenous iron improves symptoms in the short term. It is unknown, however, whether correcting iron deficiency is beneficial to patients with CHF in the long term and whether it improves life expectancy and keeps them out of hospital. This study will help us answer these key questions.

This study will address whether the additional use of Intravenous (IV) iron on top of standard care will improve the outlook for patients with heart failure and iron deficiency. One group of participants will receive treatment with iron injections and the other group will not receive any iron injections.

The study will take place in about 70 secondary care sites (hospitals) across the UK. Participants will be recruited over a period of about five years and will be followed up for a minimum of three months (average duration of about four years per participant). After the initial visits, participants will be seen every four months.

Inclusion criteria

1. Age ≥18 years
2. LVEF ≤45% within the prior two years using any conventional imaging modality (this should be the most recent assessment of LVEF)
3. New York Heart Association (NYHA) class II - IV
4. Iron deficient - defined as TSAT <20% and/or ferritin <100 ug/L
5. Evidence of being in a higher risk HF group: (a) Current (with the expectation that patient will survive to discharge) or recent (within 6 months) hospitalisation for HF, OR (b) Out-patients with NT-proBNP >250 ng/L in sinus rhythm or >1,000 ng/L in atrial fibrillation (or BNP of > 75 pg/mL or 300 pg/mL, respectively)
6. Able and willing to provide informed consent

Exclusion criteria

1. Haematological criteria: ferritin >400ug/L; haemoglobin <9.0, or >13 g/dL in women or >14g/dL in men; (B12 or folate deficiency should be corrected but do not exclude the patient)
2. MDRD/CKD-EPI estimated glomerular filtration rate (eGFR) <15ml/min/1.73m2
3. Already planned to receive IV iron
4. Likely to need or already receiving erythropoiesis stimulating agents (ESA)
5. Any of the following apply: (a) planned cardiac surgery or revascularisation; (b) within 3 months of any of the following: a primary diagnosis of type 1 myocardial infarction (excluding small troponin elevations in the context of heart failure admissions), cerebrovascular accident (CVA), major CV surgery or percutaneous coronary intervention (PCI), or blood transfusion; (c) on active cardiac transplant list; (d) left ventricular assist device implanted.
6. Any of the following comorbidities: active infection (if the patient is suffering from a significant ongoing infection as judged by the investigator recruitment should be postponed until the infection has passed or is controlled by antibiotics), other disease with life expectancy of <2 years, active clinically relevant bleeding in the investigator's opinion, known or suspected gastro-intestinal malignancy
7. Pregnancy, women of childbearing potential (i.e. continuing menstrual cycle) not using effective contraception (see Appendix 3) or breast-feeding women
8. Contra-indication to IV iron in the investigator's opinion according to current approved Summary of Product Characteristics: hypersensitivity to the active substance, to Monofer® or any of its excipients (water for injections, sodium hydroxide (for pH adjustment), hydrochloric acid (for pH adjustment)); known serious hypersensitivity to other parenteral iron products; non-iron deficiency anaemia (e.g. haemolytic anaemia); iron overload or disturbances in utilisation of iron (e.g. haemochromatosis, haemosiderosis); decompensated liver disease.
9. Participation in another intervention study involving a drug or device within the past 90 days (co-enrolment in observational studies is permitted)

Applications for data access will be considered when analysis of the main pre-specified endpoints, sub-groups and sub-studies, and other sub-analyses have been completed.

Applications for access will be considered when analysis of the main pre-specified endpoints, sub-groups and sub-studies, and other sub-analyses have been completed.

Applications for access will be reviewed by the study Steering Committee.