Re-defining iron deficiency in patients with heart failure

Iron deficiency (ID) is common in patients with chronic heart failure (CHF) and is associated with worse symptoms and prognosis regardless of whether anemia is also present. However, randomized controlled trials (RCT) of intravenous (IV) iron in patients with CHF have produced inconsistent results. This review considers the past, present, and future of defining and treating ID in patients with CHF.

The current guideline definition of ID is a serum ferritin <100 µg/L or serum ferritin 100-299 µg/L and transferrin saturation (TSAT) <20% derived from trials of IV iron in patients with end-stage renal failure. Ferritin synthesis and secretion is promoted by inflammatory cytokines which are raised in patients with CHF; thus, using ferritin to define iron deficiency in patients with CHF may be flawed. Observational data suggest that the current definition of iron deficiency in CHF does not identify a high-risk population.

Alternative indicators of ID such as low serum iron concentrations or TSAT may better identify patients with ID who are at greater risk of adverse outcome and thus, possibly, more likely to benefit from IV iron.