title: Anemia: only a marker or an independent predictor of mortality in advanced heart failure?
abstract: OBJECTIVE
  Advanced heart failure (HF) remains a major cause of mortality. Identification of new prognostic risk factors is therefore a priority. Anemia, a frequent comorbidity in HF patients and a recognized trigger of symptoms, has recently received considerable attention in this context. Several studies have demonstrated an association between anemia and increased mortality in stable chronic HF patients. However, the prognostic impact of this comorbidity on the survival of advanced HF patients remains unclear. Our aim was to assess whether anemia is not only a marker of advanced HF, but also an independent predictor of mortality.
  
  
  METHODS
  We performed a retrospective study of 391 consecutive patients admitted to a single advanced HF care unit and divided into two groups according to the presence or absence of anemia at admission. Demographic, clinical, laboratory and therapeutic data were compared between the groups. Anemia was defined as hemoglobin at admission of <12 g/dl for women and <13 g/dl for men. Appropriate statistical tests and multivariate analysis were used to identify independent predictors of one-year and overall mortality. Median follow-up was 3.2 years.
  
  
  RESULTS
  Group A, anemic patients (n=169, 43.2%), were older (61.7 +/- 14.7 vs. 58.0 +/- 14.5 years, p = 0.01) and included a higher number of patients with ischemic cardiomyopathy (40.7% vs. 28.6%, p = 0.01), but fewer with dilated cardiomyopathy (41.0% vs. 55.8%, p = 0.004). At admission, group A had lower systolic blood pressure (110.1 +/- 24.8 mmHg vs. 115.2 +/- 22.0 mmHg, p = 0.03) and higher mean C-reactive protein (1.90 +/- 3.6 mg/dl vs. 1.19 +/- 2.6 mg/dl, p = 0.004) and creatinine (1.50 +/- 0.9 mg/dl vs. 1.20 +/- 0.5 mg/dl, p < 0.001). Gender, prevalence of cardiovascular risk factors, previous medication and left ventricular ejection fraction were not statistically different between the groups. At discharge, fewer anemic patients received digoxin (71.1% vs. 81.8%, p = 0.03). Mortality rates at 3 months (13.6% vs. 6.7%, p = 0.05), one year (22.9% vs. 11%, p = 0.006) and during follow-up (39.8 % vs. 23.8%, p = 0.002) were significantly higher in Group A. Multivariate analysis demonstrated that anemia was an independent predictor of mortality at one year (p = 0.035) and during median follow-up: (p = 0.014). In the anemic group a linear relationship between hemoglobin levels and mortality was also detected.
  
  
  CONCLUSIONS
  In our population, anemia was a frequent comorbidity and had an independent and negative impact on long-term mortality. Its correction could improve outcomes in advanced HF patients.
authors.affiliation: Serviço de Cardiologia, Hospitais da Universidade de Coimbra, Coimbra, Portugal. saraiva.fatima@gmail.com
authors.forename: Fátima
authors.initials: F
authors.lastname: Saraiva
authors.forename: Hélia
authors.initials: H
authors.lastname: Martins
authors.forename: Susana
authors.initials: S
authors.lastname: Costa
authors.forename: Fatima
authors.initials: F
authors.lastname: Franco
authors.forename: Lino
authors.initials: L
authors.lastname: Gonçalves
authors.forename: Luís A
authors.initials: LA
authors.lastname: Providência
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000209:etiology*; D002648:Child; D018450:Disease Progression; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies