Effects of Intravenous Iron Replacement Therapy on Cardiovascular Outcomes in Patients with Heart Failure: A Systematic Review and Meta-Analysis

(1) Background: Iron deficiency (ID) is an important adverse prognostic marker in patients with heart failure (HF); however, it is unclear whether intravenous iron replacement reduces cardiovascular mortality in this patient group. Here, we estimate the effect of intravenous iron replacement therapy on hard clinical outcomes following the publication of IRONMAN, the largest trial in this field. (2) Methods: In this systematic review and meta-analysis, prospectively registered with PROSPERO and reported according to PRISMA guidelines, we searched PubMed and Embase for randomized controlled trials investigating intravenous iron replacement in patients with HF and co-existing ID. The primary outcome was cardiovascular mortality and secondary outcomes were all-cause mortality, hospitalizations for HF and a combination of the primary outcome and hospitalizations for HF. (3) Results: A total of 1671 items were identified and after removal of duplicates we screened titles and abstracts of 1202 records. Some 31 studies were identified for full-text review and 12 studies were included in the final review. The odds ratio (OR) for cardiovascular death using a random effects model was 0.85 (95% CI 0.69 to 1.04) and for all-cause mortality it was 0.83 (95% CI 0.59 to 1.15). There was a significant reduction in hospitalizations for HF (OR 0.49, 95% CI 0.35 to 0.69) and the combination of hospitalizations for HF and cardiovascular death (OR 0.65, 95% CI 0.5 to 0.85). (4) Conclusions: This review supports the use of IV iron replacement reducing hospitalization rates for HF, however more research is required to determine the effect on cardiovascular mortality and to identify the patient population most likely to benefit.