Iron deficiency: Prevalence and relation to cardiovascular biomarkers in heart failure outpatients

BackgroundBoth iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked.ObjectivesTo identify the prevalence of ID in a HF clinic and evaluate whether ID is associated with increased plasma concentrations of different cardiovascular biomarkers that carry a poor prognosis.MethodsWe prospectively included 149 patients with systolic HF referred to an outpatients HF clinic. ID was defined as ferritin < 100 μg/L or ferritin 100-300 μg/L and Tranferin-saturation < 0.20. Five different cardiovascular biomarkers were analyzed on frozen plasma.ResultsThe patients had a median age of 70 (Interquartile range: 64-75) years, 25% were females, 29% were in functional class III-IV and LVEF was 32 (27-39) %. The prevalence of ID was 45% (95%-confidence interval (CI): 37-53%). In multivariate analyses, ID was not associated with plasma concentrations of troponin I, NT-proBNP, MR-proANP, chromogranin A or copeptin (P > 0.05 for all) but with plasma concentrations of hs-CRP (odds ratio: 2.03, 95%-CI: 1.02-4.02, P = 0.043).ConclusionID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF patients