Effect of Intravenous Ferrous Sucrose on Exercise Capacity in Chronic Heart Failure

This is a two-center, randomised, single-blind (physician), prospective, controlled study to assess the acute (8 weeks) and chronic (16 weeks) effects of intravenous (IV) iron sucrose supplementation in anaemic and non-anaemic iron deficient patients with chronic heart failure (CHF).

The hypotheses are:

* Treatment of anaemic and non-anaemic iron-deficient CHF patients with IV iron sucrose improves exercise capacity as measured by peak VO2.
* IV iron sucrose is safe and well tolerated in subjects with moderate to severe CHF.

Study Phase and Design:

Prospective two-centre, randomized, controlled, open-label, observer-blinded, parallel-group study

Primary Objective:

To evaluate the effect of intravenous (IV) iron supplementation on exercise tolerance, as determined by peak VO2.

Secondary Objectives:

* To evaluate the effects of IV iron supplementation on exercise duration, left ventricular (LV) structure and function, symptom status (NYHA class, Minnesota Living with Heart Failure Questionnaire \[MLHFQ\], and subjective fatigue score), and haematological and biochemical (haemoglobin \[Hb\], haematocrit \[Hct\], iron status, N-BNP, cytokines and oxidative stress) indices.
* To evaluate the safety profile of IV iron in subjects with moderate to severe CHF.

Sample Size:

42 subjects (28 IV iron, 14 placebo); 50% anaemic and 50% non-anaemic

Eligibility Criteria:
Inclusion Criteria:

* ≥21 years of age and have signed written informed consent
* Stable symptomatic CHF; NYHA III/IV and left ventricular ejection fraction (LVEF) ≤40%, or if NYHA II then LVEF must be ≤35%, as assessed within last 6 months using echocardiographic or magnetic resonance imaging techniques.
* On optimal conventional therapy for at least 4 weeks prior to recruitment and without dose changes for at least 2 weeks.
* Peak VO2 ≤ 18 ml/kg/min on modified Naughton protocol cardiopulmonary exercise testing.
* Mean of the 2 screening Hb concentrations (week-2 and week-1) \< 12.5 g/dl (anaemic group, 50% of study population) or 12.5-14.0 g/dl (non-anaemic group, 50% of study population).
* Ferritin \<100 µg/l or 100-300 µg/l with TSAT \<20%.
* Normal red cell folate and vitamin B12 status (according to local lab reference range).
* Resting blood pressure ≤160/100 mmHg.

Exclusion Criteria:

* History of acquired iron overload; known haemochromatosis or first relatives with haemochromatosis; and allergic disorders (asthma, eczema, and anaphylactic reactions).
* Known hypersensitivity to parental iron preparations.
* Known active infection, bleeding, malignancy and haemolytic anaemia.
* History of chronic liver disease and/or alanine transaminase (ALT) or aspartate transaminase (AST) \>3 times the upper limit of the normal range; chronic lung disease; myelodysplastic disorder; and known HIV/AIDS disease.
* Recipient of immunosuppressive therapy or renal dialysis.
* History of erythropoietin, IV or oral iron therapy, and blood transfusion in previous 30 days.
* Unstable angina pectoris, as judged by the investigator; severe uncorrected valvular disease or left ventricular outflow obstruction; obstructive cardiomyopathy; uncontrolled fast atrial fibrillation or flutter (heart rate \>110 beats per minute \[bpm\]); uncontrolled symptomatic brady- or tachyarrhythmias.
* Musculoskeletal limitation that, in the judgement of the investigator, would impair cardiopulmonary exercise testing.
* Pregnant or breast-feeding
* Inability to comprehend study protocol
* Parallel participation in another clinical trial