Iron Deficiency in Heart Failure: Characteristics and Treatment.

Purpose of the review: Iron deficiency in heart failure has been associated with impaired functional capacity and quality of life. The purpose of this paper is to review mechanisms of iron homeostasis and current clinical data exploring mechanisms of iron repletion in heart failure.

Recent finding: Multiple international societies now advise iron repletion for symptomatic heart failure patients with iron deficiency. Due to the chronic inflammation in heart failure, iron deficiency in heart failure is classically defined as ferritin < 100 µg/L or ferritin 100-300 µg/L and transferrin saturation < 20%. Multiple randomized clinical trials have demonstrated benefit from intravenous iron repletion, though studies have predominantly focused on functional capacity and quality of life. A recent study, AFFIRM-AHF, supports the treatment of iron deficiency identified during acute heart failure admissions, noting a reduction in future heart failure hospitalizations. Studies examining iron repletion in patients with heart failure with preserved ejection fraction are currently in process.

Summary: Iron homeostasis is maintained predominantly through the regulation of iron absorption, keeping iron levels tightly controlled in the normal state regardless of iron intake. In chronic heart failure however, iron homeostasis becomes dysregulated with resulting iron deficiency in many patients, with and without associated anemia. Iron is a critical element not only for erythropoiesis and oxygen carrying, but also for energy production at the level of the mitochondria and in other cell processes. We thus propose a standardized approach be utilized to screen and treat heart failure patients with iron deficiency.