Evidence-Based Practice | 2021
Treating iron deficiency may improve cardiovascular outcomes in heart failure patients
Abstract
This meta-analysis of 10, small, randomized control trials compared iron supplementation versus placebo in 1,404 patients with iron deficiency and systolic heart failure. The trials varied in treatment routes and dosages, follow-up time frames, and end points. Iron replacement therapies included oral and intravenous supplementation. Patients who received iron supplementation had fewer heart failure exacerbation hospitalizations (odds ratio [OR], 0.39; 95% CI, 0.19–0.80) and a reduced combined end point of death and heart failure hospitalizations (OR, 0.47; 95% CI, 0.32–0.69) compared with placebo but did not show a statistical reduction in all-cause mortality. Other outcomes included improvement in New York Heart Association class (weighted mean difference [WMD], –0.68; 95% CI, –1.13, –0.24), six-minute walk distance (WMD, 32.7 m; 95% CI, 4.5–60.8), left ventricular ejection fraction (WMD, 3.8%; 95% CI, 1.1–6.5), and peak oxygen consumption (WMD, 0.89 mL/min; 95% CI, 0.14–1.64). Symptomatic outcomes such as Patient Global Assessment (range, 0–10; WMD, 0.71; 95% CI, 0.33–1.09), Kansas City Cardiomyopathy Questionnaire score (range, 0–100; WMD, 4.09; 95% CI, 0.61–7.56), European quality of life-five Dimensions score (range, 5–25; WMD, 4.07; 95% CI, 0.84–7.31), and the Minnesota Living with Heart Failure Questionnaire score (range, 0–105, with lower better; WMD, –19.4; 95% CI, –23.4 to –15.5) were improved in patients after iron therapy. These secondary outcomes showed statistical improvement but may be less reliable clinically because of smaller number of patients included. Intravenous iron supplementation was found to have more consistent improved outcomes over oral administration. Further studies are recommended to confirm these results.