Red cell distribution width as predictive marker in CHF: testing of model performance by reclassification methods.

In the last 10 years, there has been growing interest in the relationship between chronic heart failure (CHF) and anemia. Low blood hemoglobin content has been reported to be highly prevalent and to be associated with poor outcome in CHF [ 1 Kosiborod M. Smith G.L. Radford M.J. Foody J.M. Krumholz H.M. The prognostic importance of anemia in patients with heart failure. Am J Med. 2003; 114: 112-119 Abstract Full Text Full Text PDF PubMed Scopus (256) Google Scholar , 2 Anker S.D. Comin Colet J. Filippatos G. et al. Ferric carboxymaltose in patients with heart failure and iron deficiency. N Engl J Med. 2009; 361: 2436-2448 Crossref PubMed Scopus (1292) Google Scholar ]. The red blood cell distribution width (RDW) is a measure of the variation and an index of the heterogeneity of red blood cell (RBC) volume. Since the time of the original description of RDW as a novel prognostic marker in chronic heart failure [ [3] Felker G.M. Allen L.A. Pocock S.J. et al. Red cell distribution width as a novel prognostic marker in heart failure: data from the CHARM Program and the Duke Databank. J Am Coll Cardiol. 2007; 50: 40-47 Abstract Full Text Full Text PDF PubMed Scopus (695) Google Scholar ] at least 5 studies (including our current study with 1-year survival data) confirmed this observation in CHF with various follow-up periods [ 4 Forhecz Z. Gombos T. Borgulya G. Pozsonyi Z. Prohaszka Z. Janoskuti L. Red cell distribution width in heart failure: prediction of clinical events and relationship with markers of ineffective erythropoiesis, inflammation, renal function, and nutritional state. Am Heart J. 2009; 158: 659-666 Abstract Full Text Full Text PDF PubMed Scopus (438) Google Scholar , 5 Jung C. Fujita B. Lauten A. et al. Red blood cell distribution width as useful tool to predict long-term mortality in patients with chronic heart failure. Int J Cardiol. 2011; 152: 417-418 Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar , 6 Al-Najjar Y. Goode K.M. Zhang J. Cleland J.G. Clark A.L. Red cell distribution width: an inexpensive and powerful prognostic marker in heart failure. Eur J Heart Fail. 2009; 11: 1155-1162 Crossref PubMed Scopus (133) Google Scholar , 7 Allen L.A. Felker G.M. Mehra M.R. et al. Validation and potential mechanisms of red cell distribution width as a prognostic marker in heart failure. J Card Fail. 2010; 16: 230-238 Abstract Full Text Full Text PDF PubMed Scopus (291) Google Scholar , 8 Zalawadiya S.K. Zmily H. Farah J. Daifallah S. Ali O. Ghali J.K. Red cell distribution width and mortality in predominantly African-American population with decompensated heart failure. J Card Fail. 2011; 17: 292-298 Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar ]. RDW has emerged as a new prognostic biomarker in cardiovascular diseases, as reviewed recently Montagnana et al. [ [9] Montagnana M. Cervellin G. Meschi T. Lippi G. The role of red blood cell distribution width in cardiovascular and thrombotic disorders. Clin Chem Lab Med. 2012; 50: 635-641 Google Scholar ]. High levels of RDW are associated with elevated cardiovascular biomarkers [ [10] Holmstrom A. Sigurjonsdottir R. Hammarsten O. Gustafsson D. Petzold M. Fu M.L. Red blood cell distribution width and its relation to cardiac function and biomarkers in a prospective hospital cohort referred for echocardiography. Eur J Intern Med. 2012; 23: 604-609 Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar ] and as our group reported previously are also associated with increased 1-year mortality in CHF, and correlate with inflammation, ineffective erythropoiesis, undernutrition and impaired renal function [ [4] Forhecz Z. Gombos T. Borgulya G. Pozsonyi Z. Prohaszka Z. Janoskuti L. Red cell distribution width in heart failure: prediction of clinical events and relationship with markers of ineffective erythropoiesis, inflammation, renal function, and nutritional state. Am Heart J. 2009; 158: 659-666 Abstract Full Text Full Text PDF PubMed Scopus (438) Google Scholar ]. A few studies have shown that RDW is a powerful prognostic marker of long-term mortality in HF [ 3 Felker G.M. Allen L.A. Pocock S.J. et al. Red cell distribution width as a novel prognostic marker in heart failure: data from the CHARM Program and the Duke Databank. J Am Coll Cardiol. 2007; 50: 40-47 Abstract Full Text Full Text PDF PubMed Scopus (695) Google Scholar , 5 Jung C. Fujita B. Lauten A. et al. Red blood cell distribution width as useful tool to predict long-term mortality in patients with chronic heart failure. Int J Cardiol. 2011; 152: 417-418 Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar , 6 Al-Najjar Y. Goode K.M. Zhang J. Cleland J.G. Clark A.L. Red cell distribution width: an inexpensive and powerful prognostic marker in heart failure. Eur J Heart Fail. 2009; 11: 1155-1162 Crossref PubMed Scopus (133) Google Scholar ]. The present study aimed to analyze the association of RDW values with overall 5-year survival in CHF, and to evaluate the importance of RDW by novel statistical approach.