Influence of serum transferrin concentration on diagnostic criteria for iron deficiency in chronic heart failure

Abstract Aims Transferrin saturation (TSAT), a marker of iron deficiency, reflects both serum concentrations of iron (SIC) and transferrin (STC). TSAT is susceptible to changes in each of these biomarkers. Little is known about determinants of STC and its influence on TSAT and mortality in patients with heart failure. Accordingly, we studied the relationship of STC to clinical characteristics, to markers of iron deficiency and inflammation and to mortality in chronic heart failure (CHF). Methods and results Prospective cohort of patients with CHF attending a clinic serving a large local population. A total of 4422 patients were included (median age 75 (68–82) years; 40% women; 32% with left ventricular ejection fraction ≤40%). STC ≤ 2.3 g/L (lowest quartile) was associated with older age, lower SIC and haemoglobin and higher high‐sensitivity C‐reactive protein, ferritin and N‐terminal pro‐brain natriuretic peptide compared with those with STC > 2.3 g/L. In the lowest STC quartile, 624 (52%) patients had SIC ≤13 μmol/L, of whom 38% had TSAT ≥20%. For patients in the highest STC quartile, TSAT was 13 μmol/L in 185 (17%) patients. STC correlated inversely with ferritin (r = −0.52) and high‐sensitivity C‐reactive protein (r = −0.17) and directly with albumin (r = 0.29); all P 20% and serum ferritin >100 μg/L; such patients have a high prevalence of anaemia and a poor prognosis and might have iron deficiency but are currently excluded from clinical trials of iron repletion