This study aimed to determine if intravenous iron (ferric carboxymaltose) would improve symptoms in patients with heart failure, reduced left ventricular function, and iron deficiency anemia. Patients with chronic heart failure classified as NYHA class II or III, a left ventricular ejection fraction of 40% or less (II) or 45% or less (III), and microcytic hypochromic anemia were randomly assigned to receive either 200 mg of intravenous iron or a saline placebo. The primary endpoints were self-reported health status and NYHA functional class at 24 weeks, with secondary endpoints including 6-minute walk distance and quality of life.