title: Association between Red Cell Distribution Width and Mortality after Cardiac Resynchronization Therapy.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) is a non-pharmacological option for patients with heart failure and interventricular dyssynchrony. Elevated red cell distribution width (RDW) reflects higher size and heterogeneity of erythrocytes and is associated with poor outcome in patients with chronic heart failure.
  
  
  OBJECTIVE
  To examine the association between RDW levels and outcomes after CRT implantation.
  
  
  METHODS
  We conducted a cohort analysis of 156 patients (126 men, median age 69.0 years) who underwent CRT implantation in our institution during 2004-2008. RDW was measured at three time points before and after implantation. Primary outcome was defined as all-cause mortality, and secondary outcome as hospital re-admissions. We investigated the association between RDW levels and primary outcome during a median follow-up of 61 months.
  
  
  RESULTS
  Ninety-five patients (60.9%) died during follow-up. Higher baseline RDW levels were associated with all-cause mortality (unadjusted HR 1.35, 95% CI 1.20-1.52, P < 0.001). On multivariate analysis adjusted for clinical, electrocardiographic and laboratory variables, baseline RDW levels were associated with mortality (HR 1.33, 95%CI 1.16-1.53). RDW levels 6 months and 12 months post-implantation were also associated with mortality (HR 1.22, 95%CI 1.08-1.38, P = 0.001; and HR 1.15, 95% CI 1.01-1.32, P = 0.02, respectively). Patients who were re-admitted to hospital during follow-up (n = 78) had higher baseline RDW levels as compared to those who were not (14.9%, IQR 14.0, 16.0% vs. 14.3%, IQR 13.7, 15.0%, respectively, P = 0.03).
  
  
  CONCLUSIONS
  An elevated RDW level before and after CRT implantation is independently associated with all-cause mortality.
authors.forename: Guy
authors.initials: G
authors.lastname: Topaz
authors.forename: Moti
authors.initials: M
authors.lastname: Haim
authors.forename: Jairo
authors.initials: J
authors.lastname: Kusniec
authors.forename: Shirit
authors.initials: S
authors.lastname: Kazum
authors.forename: Gustavo
authors.initials: G
authors.lastname: Goldenberg
authors.forename: Gregory
authors.initials: G
authors.lastname: Golovchiner
authors.forename: Ran
authors.initials: R
authors.lastname: Kornowski
authors.forename: Boris
authors.initials: B
authors.lastname: Strasberg
authors.forename: Alon
authors.initials: A
authors.lastname: Eisen
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods; D002908:Chronic Disease; D004909:Erythrocyte Indices; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis / Q000401:mortality / Q000628:therapy; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis