Efficacy of intravenous iron therapy in iron-deficient patients with heart failure: an updated systematic review and meta-analysis

Abstract

Abstract Background/Introduction Iron deficiency is a common finding in chronic diseases such as heart failure (HF), as well as being a predictor of worse functional class and a higher risk of death in patients with a reduced/moderated reduced left ventricular ejection fraction (HFrEF/HFmrEF). Despite numerous trials evaluating iron supplementation in patients with HF and iron deficiency, the impact on mortality and hospitalisations is not well-established. Purpose The aim of our study was to assess the efficacy of IV iron supplementation on clinical and blood biochemical outcomes in iron-deficient patients with heart failure (HFmrEF and HFrEF). Methods We systematically searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials for randomised controlled trials (RCTs) studying the effects of iron therapy in patients with HF. Statistical analysis was performed using RevMan 5.1.7. Heterogeneity was assessed with I² statistics; p-values inferior to 0.10 and I²>25% were classified with significant heterogeneity. Results Ten RCTs were included comprising a total of 3447 participants, of whom 1810 (52.5%) have received iron infusion. The 6-minute walk distance after 12 weeks of treatment was significantly higher in those who received iron supplementation (MD 54.23; 95% CI 25.41-83.05; p = 0.0002; I² = 64%; Fig. number 1A). Hospital admissions for heart failure were significantly lower in patients randomised to iron therapy when compared with the control group (OR 0.57; 95% CI 0.46-0.70; p <0.001; I² = 17%; Fig. number 1B). There was no statistically significant difference among groups regarding cardiovascular death (OR 0.87; 95% CI 0.71-1.07; p = 0.19; I² = 0%; Fig. number 2A ), all-cause hospitalisations (OR 1.00; 95% CI 0.37-2.73; p = 1.00; I² = 81%; Fig. number 2B), and hospital admissions for cardiovascular causes (OR 0.72; 95% CI 0.4-1.33; p = 0.3; I² = 77%). Ferritin levels have shown a significant increase (MD 212.34; 95% CI 127.05-297.62; I² = 98%). Conclusion(s) This meta-analysis suggests that intravenous iron supplementation in patients with heart failure and iron deficiency was associated with a lower risk of hospital admissions for heart failure and improved exercise capacity, albeit with inconclusive data about the reduction in cardiovascular mortality.Relevant clinical outcomesSecondary relevant clinical outcomes