TF and heart failure: FERRIC-HF was a randomized, double-blind, placebo-controlled clinical trial of 40 patients with symptomatic heart failure with reduced ejection fraction, iron deficiency (defined as serum ferritin of less than 100 ng/mL or serum ferritin 100 to 300 ng/mL with a transferrin saturation of less than 20%), and normal folate and vitamin B12 levels51.