Prevalence of Risk of Thrombosis and of Bleeding and Antithrombotic Treatment in Patients with Heart Failure

Given the strong link between iron status and FGF23 levels, one may expect changes in FGF23 levels after iron administration.Conflicting data have been published on the effect of intravenous iron administration on FGF23 levels.In a small cohort of iron-deficient patients with HF and reduced ejection fraction, c-terminal FGF23 levels decreased after ferric carboxymaltose (FCM) administration during 28 days of followup, with transient hypophosphataemia and short-term increase in intact FGF23 levels.9 Contrarily, another study comparing FCM and iron sucrose in haemodialysis patients found a short-term drop in intact FGF23 and a rise in c-terminal FGF23 in patients receiving FCM, whereas iron sucrose did not affect these parameters.12 Currently, no large studies on the effect of different iron agents on FGF23 levels in HF have been published.When intravenous iron therapy substantially and persistently lowers FGF23 levels, this might provide an additional explanation for the mode of action of this treatment modality, besides its beneficial haematological effects.Our study has several strengths and limitations.First, we used a large and welldescribed cohort of worsening HF patients, in which we measured FGF23 and multiple iron parameters.We acknowledge the observational nature of our study, making it challenging to directly study pathophysiological mechanisms.Second, using the FGF23 assay we used for our study, we could not distinguish c-terminal FGF23 from intact FGF23.Finally, most patients in BIOSTAT-CHF have a reduced ejection fraction.Our data should therefore be cautiously interpreted in HF patients with a preserved ejection fraction. FundingThe BIOSTAT-CHF study was supported by the European Commission (FP7-242209-BIOSTAT-CHF). Conflict of interest: