As a clinical pharmacist, you'll hear about using IV iron to improve heart failure symptoms. This is very preliminary, but could be important if it pans out. Up to 20% of heart failure patients are iron deficient which can lead to fatigue and exercise intolerance.
Now evidence shows that treating iron deficiency can help patients with moderate symptomatic systolic heart failure. They feel better, can walk further and have a better quality of life. Benefits are seen regardless of whether these patients are anemic or just iron deficient without anemia. Researchers are trying this in patients with a serum ferritin < 100 ng/mL or 100 to 299 ng/mL with a transferrin saturation < 20%.
Consider checking for iron deficiency or anemia in patients with symptomatic heart failure. If you want to try IV iron, use iron sucrose (Venofer, Ferosac, Sacrofer) 200 mg/week until iron stores are replete and then 200 mg/month for 4 to 6 months. IV iron replaces iron stores faster than oral iron and the risk of anaphylaxis is very small with the newer IV products (Venofer, Sacrofer, Feraheme, etc). Monitor ferritin, transferrin saturation, and hemoglobin to make sure patients maintain sufficient iron stores.
REFERENCES
Anker, S.D., Comin Colet, J., and others (2009). Ferric Carboxymaltose in Patients with Heart Failure and Iron Deficiency. New England Journal of Medicine, 361(25), pp.2436–2448. Available at: https://www.nejm.org/doi/full/10.1056/nejmoa0908355
Okonko DO, Grzeslo A, Witkowski T, Mandal AK, Slater RM, Roughton M, Foldes G, Thum T, Majda J, Banasiak W, Missouris CG, Poole-Wilson PA, Anker SD, Ponikowski P. Effect of intravenous iron sucrose on exercise tolerance in anemic and nonanemic patients with symptomatic chronic heart failure and iron deficiency FERRIC-HF: a randomized, controlled, observer-blinded trial. J Am Coll Cardiol. 2008 Jan 15;51(2):103-12. Available at: https://pubmed.ncbi.nlm.nih.gov/18191732