Iron supplementation for the treatment of chronic heart failure and iron deficiency: systematic review and meta-analysis

Over half of chronic heart failure (CHF) patients are anaemic, and iron deficiency is common. Iron replacement therapy (oral or i.v.) might improve exercise capacity and quality of life (QOL). We carried out a systematic review and meta-analysis of all randomized control trials that compared iron with no therapy for CHF patients with iron deficiency, whether or not they were anaemic. We searched electronic databases as well as haematology and cardiology conferences up to August 2011. The primary outcome was the effect of iron on QOL parameters such as New York Heart Association (NYHA) class and the Minnesota Living With Heart Failure Questionnaire (MLHWFQ). Secondary outcomes included all-cause mortality, mean ejection fraction, 6 min walk distance (6MWD), hospitalizations due to any cause, iron indices, C-reactive protein levels, and adverse events. Four trials performed fulfilled the inclusion criteria. A total of 370 patients were treated with i.v. iron, compared with 224 control patients. There was significant improvement in QOL in the iron arm according to the MLWHFQ score at 26 weeks, with a weighted mean difference of 18.00 (22.54, 13.46, I-2 0]. The point estimate for improvement in NYHA class was in favour of iron. Iron reduced the number of hospitalizations and C-reactive protein levels, and increased the 6MWD and mean ejection fraction. Iron indices were significantly improved without a change in haemoglobin levels. No increase in the rate of adverse events was found. Intravenous iron therapy is associated with improved QOL parameters, reduction in hospitalizations, and increased 6MWD. Treatment with i.v. iron is safe, with no increased rate of adverse events. The results of our analysis are limited by the paucity of trials, and significant heterogeneity between trials.