Background: Iron deficiency is prevalent in patients with heart failure. This meta-analysis was performed to evaluate the therapeutic effects of iron in patients with systolic heart failure and iron deficiency.

Methods: We searched PubMed, Embase, and Cochrane databases through March 2018 and included 10 randomized controlled trials involving 1404 heart failure patients who underwent iron or placebo treatment. Odds ratio (OR) and weighted mean differences (WMD) were calculated using fixed- or random-effects models.

Results: Our results showed that iron supplementation significantly reduced hospitalization for worsening heart failure (OR 0.39; 95% confidence interval [CI], 0.19-0.80) and the combined endpoint of death and heart failure hospitalization (OR 0.47; 95% CI, 0.32-0.69). In addition, iron treatment was found to improve New York Heart Association class, 6-minute walk distance, left ventricular ejection fraction, and peak oxygen consumption. Iron therapy was also associated with improvements in Patient Global Assessment, Kansas City Cardiomyopathy Questionnaire score, European Quality of Life-5 Dimensions score, and Minnesota Living with Heart Failure Questionnaire score. Moreover, serum levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and C-reactive protein (CRP) were markedly decreased in patients with iron repletion compared with placebo treatment (WMD: -332.48 pg/mL; 95% CI, -497.48 to -167.47; WMD: -4.64 mg/L; 95% CI, -6.12 to -3.17, respectively).

Conclusions: Our meta-analysis suggests that iron therapy can reduce heart failure hospitalization, increase cardiac function, improve quality of life, and decrease serum levels of NT-proBNP and CRP in patients with heart failure.