Expansion of the red cell distribution width and evolving iron deficiency as predictors of poor outcome in chronic heart failure.
BACKGROUND
An elevated red cell distribution width (RDW) and iron deficiency (ID) at baseline predict enhanced mortality in chronic heart failure (CHF), but little is known about the prognostic implications of their temporal trends. We sought to determine the survival implications of temporal changes in RDW and evolving ID in patients with CHF.


METHODS
The relation between red cell indices on first consultation and over time with mortality in 274 stable patients with systolic CHF was analysed. The combination of a rising RDW with a falling mean cell volume (MCV) over time defined evolving ID.


RESULTS
Over a median 12 month period, 51% and 23% of patients had a rise in RDW and evolving ID, respectively. After a median follow-up of 27 months, 60 (22%) patients died. A rising RDW predicted enhanced all-cause mortality (unadjusted HR for 1% per week rise 9.27, 95% CI 3.58 to 24.00, P<0.0001) independently and incrementally to baseline RDW, with an absolute increase >0.02% per week optimally predictive. Evolving ID also related to higher rates of mortality (HR 2.78, 95% CI 1.64 to 4.73, P<0.001) and was prognostically worse than a rising RDW alone (P<0.005). Patients with evolving ID who maintained their Hb levels over time had a 2-fold greater risk of death than those whose Hb levels declined without evolving ID.


CONCLUSIONS
An expanding RDW and evolving iron deficiency over time predict an amplified risk of death in CHF and should be utilised for risk stratification and/or therapeutically targeted to potentially improve outcomes.
University College London Hospital, London, UK.
Nay
N
Aung
Hua Zen
HZ
Ling
Adrian S
AS
Cheng
Suneil
S
Aggarwal
Julia
J
Flint
Michelle
M
Mendonca
Mohammed
M
Rashid
Swan
S
Kang
Susanne
S
Weissert
Caroline J
CJ
Coats
Toby
T
Richards
Martin
M
Thomas
Simon
S
Woldman
Darlington O
DO
Okonko
D000368:Aged; D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000453:epidemiology / Q000209:etiology; D004906:Erythrocyte Count; D004909:Erythrocyte Indices / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood* / Q000150:complications / Q000401:mortality; D006801:Humans; D007501:Iron / Q000097:blood*; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology
D007501:Iron
Heart failure; Iron; RDW