Iron deficiency (ID) is highly prevalent in patients with heart failure (HF) but its impact on prognosis in HFpEF remains unclear. We assessed whether ID defined by sTfR criteria is independently associated with all-cause mortality in HFpEF patients, and evaluated its comparative prognostic performance to ID definitions in common clinical use.
Data were analysed from 788 patients (36% HFpEF) in a prospective multi-centre heart failure cohort study. Baseline plasma samples were analysed with respect to four definitions of ID: sTfR≥1.59mg/L(ID), sTfR≥1.76mg/L(ID), ferritin<100mcg/l or ferritin100-300mcg/L+transferrin saturation<20%(ID), and transferrin saturation<20%(ID). In multivariable Cox models ID(HR 1.84[95%CI 1.23-2.75]) and ID(HR 1.69[95%CI 1.10-2.59]) were both independently associated with all-cause mortality in HFpEF patients, whilst ID(HR 1.41[95%CI 0.92 – 2.16]) and ID(HR 1.19[95%CI 0.77-1.85]) were not. On inclusion of HFrEF patients, ID(HR 1.45[95%CI 1.13-1.86]) gained significance but ID(HR 1.21 [95%CI 0.95-1.54]) did not. For each pair of definitions intra-patient concordance was ∼65%.
ID defined by sTfR criteria is independently associated with all-cause mortality in HFpEF patients. Poor concordance between ID definitions, suggests iron biomarkers do not reflect the same pathological process in the complex relationship between iron and HF. Therefore, which definition should guide iron replacement needs further evaluation.
Copyright © 2022. Published by Elsevier Inc.

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