title: The effect of intravenous ferric carboxymaltose on red cell distribution width: a subanalysis of the FAIR-HF study.
abstract: OBJECTIVE
  Red cell distribution width (RDW), a measure of variability in red blood cell size, is a novel prognostic marker in chronic heart failure (CHF). Iron deficiency contributes to elevated RDW. In the FAIR-HF trial, i.v. ferric carboxymaltose (FCM) improved the 6 min walk test (6MWT) distance in iron-deficient CHF patients. We studied the effect of FCM on RDW and the relationship between RDW and 6MWT distance.
  
  
  RESULTS
  In FAIR-HF, iron-deficient CHF patients were randomized to FCM or placebo in a 2:1 ratio. From the total cohort (n = 459), we included 415 patients in whom RDW values and 6MWT distance were available for baseline and at least one follow-up visit (after 4, 12, and 24 weeks). Baseline RDW was higher in anaemic (haemoglobin <12 g/dL) compared with non-anaemic patients [15.2% (14.0-16.8) vs. 14.2% (13.4-15.4), P < 0.0001, median (interquartile range)]. In multivariate analysis, RDW was significantly associated with transferrin saturation (P < 0.001) and C-reactive protein levels (P = 0.002). Treatment with FCM led to a biphasic response; RDW increased within 4 weeks (+0.54% absolute change from baseline, P = 0.01) but fell to values below the placebo group after 24 weeks (-1.0 %, P = 0.03). The 6MWT distance and RDW were inversely related at baseline (r = -0.30, P < 0.0001). In all patients, the increase in 6MWT distance after 24 weeks was significantly correlated with a decrease in RDW (r= -0.25, P < 0.0001), even after adjustment for changes in haemoglobin.
  
  
  CONCLUSIONS
  Iron deficiency in CHF is associated with high RDW, even after adjustment for the presence of anaemia. Treatment with i.v. FCM in iron-deficient CHF patients decreases RDW.
authors: Department of Cardiology, Antwerp University Hospital, Edegem, Belgium. Emeline.Vancraenenbroeck@ua.ac.be
authors: Emeline M
authors: EM
authors: Van Craenenbroeck
authors: Viviane M
authors: VM
authors: Conraads
authors: Nicola
authors: N
authors: Greenlaw
authors: Giedrius
authors: G
authors: Gaudesius
authors: Claudio
authors: C
authors: Mori
authors: Piotr
authors: P
authors: Ponikowski
authors: Stefan D
authors: SD
authors: Anker
mesh_terms: D000368:Aged; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004909:Erythrocyte Indices / Q000187:drug effects*; D005260:Female; D005290:Ferric Compounds / Q000008:administration & dosage*; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008320:Maltose / Q000008:administration & dosage / Q000031:analogs & derivatives*; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D005290:Ferric Compounds; D006454:Hemoglobins; C522335:ferric carboxymaltose; D008320:Maltose
keywords: Chronic heart failure; Exercise capacity; Ferric carboxymaltose; Iron deficiency; Red cell distribution width