Effects of intravenous iron therapy in iron-deficient patients with systolic heart failure: a meta-analysis of randomized controlled trials

The aim of this study was to assess the net clinical and prognostic effects of intravenous (i.v.) iron therapy in patients with systolic heart failure (HF) and iron deficiency (ID). We performed an aggregate data meta-analysis (random effects model) of randomized controlled trials that evaluated the effects of i.v. iron therapy in iron-deficient patients with systolic HF. We searched electronic databases up to September 2014. We identified five trials which fulfilled the inclusion criteria (509 patients received i.v. iron therapy in comparison with 342 controls). Intravenous iron therapy has been shown to reduce the risk of the combined endpoint of all-cause death or cardiovascular hospitalization [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.30-0.64, P < 0.0001], and the combined endpoint of cardiovascular death or hospitalization for worsening HF (OR 0.39, 95% CI 0.24-0.63, P = 0.0001). Intravenous iron therapy resulted in a reduction in NYHA class (data are reported as a mean net effect with 95% CIs for all continuous variables) (-0.54 class, 95% CI -0.87 to -0.21, P = 0.001); an increase in 6-min walking test distance (+31 m, 95% CI 18-43, P < 0.0001); and an improvement in quality of life [Kansas City Cardiomyopathy Questionnaire (KCCQ) score +5.5 points, 95% CI 2.8-8.3, P < 0.0001; European Quality of Life-5 Dimensions (EQ-5D) score +4.1 points, 95% CI 0.8-7.3, P = 0.01; Minnesota Living With Heart Failure Questionnaire (MLHFQ) score -19 points, 95% CI:-23 to -16, P < 0.0001; and Patient Global Assessment (PGA) +0.70 points, 95% CI 0.31-1.09, P = 0004]. The evidence indicates that i.v. iron therapy in iron-deficient patients with systolic HF improves outcomes, exercise capacity, and quality of life, and alleviates HF symptoms.