title: Hospital-acquired anemia and in-hospital mortality in patients with acute myocardial infarction.
abstract: BACKGROUND
  Hospital-acquired anemia (HAA) is common during acute myocardial infarction (AMI) and associated with higher long-term mortality. The relationship between HAA and adverse in-hospital outcomes may be particularly relevant to hospitals' efforts to implement prevention programs, but the association between HAA and in-hospital mortality is unclear.
  
  
  METHODS
  We studied 17,676 patients with AMI with normal admission hemoglobin level who did not undergo bypass surgery. Hospital-acquired anemia was defined as development of new anemia during hospitalization (based on nadir hemoglobin) using age-, gender-, and race-specific criteria. In-hospital mortality of patients with mild (hemoglobin level less than HAA threshold but >11 g/dL), moderate (hemoglobin level 9-11 g/dL), and severe HAA (hemoglobin level, < 9 g/dL) was compared with those without HAA using hierarchical logistic regression, adjusting for site and potential confounders.
  
  
  RESULTS
  Hospital-acquired anemia developed in 10,166 patients (57.5%); 6,615 (37.4%) had mild; 2,740 (15.5%), moderate; and 811 (4.6%), severe HAA. In-hospital mortality was higher in patients with HAA and increased with HAA severity (no HAA 266 [3.5%], mild HAA 260 [3.9%], moderate HAA 222 [8.1%], and severe HAA 148 [18.3%], P < .001). The adjusted odds of in-hospital death were greater in patients with moderate (odds ratio 1.38, 95% CI 1.10-1.73) and severe HAA (3.39, 95% CI 2.59-4.44) versus no HAA.
  
  
  CONCLUSIONS
  Moderate and severe HAAs are independently associated with higher in-hospital mortality during AMI. Studies are needed to determine whether HAA is preventable and if preventing HAA improves outcomes.
authors.affiliation: Saint Luke's Mid-Asmerica Heart and Vascular Institute, Kansas City, MO 64111, USA.
authors.forename: Adam C
authors.initials: AC
authors.lastname: Salisbury
authors.forename: Amit P
authors.initials: AP
authors.lastname: Amin
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Reid
authors.forename: Tracy Y
authors.initials: TY
authors.lastname: Wang
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Masoudi
authors.forename: Paul S
authors.initials: PS
authors.lastname: Chan
authors.forename: Karen P
authors.initials: KP
authors.lastname: Alexander
authors.forename: Richard G
authors.initials: RG
authors.lastname: Bach
authors.forename: John A
authors.initials: JA
authors.lastname: Spertus
authors.forename: Mikhail
authors.initials: M
authors.lastname: Kosiborod
mesh_terms: D000368:Aged; D000740:Anemia / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006454:Hemoglobins / Q000378:metabolism; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000150:complications* / Q000401:mortality; D011379:Prognosis; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology
chemical_list: D006454:Hemoglobins