title: Risk factors for adverse outcomes by left ventricular ejection fraction in a contemporary heart failure population.
abstract: BACKGROUND
  Although heart failure (HF) is a syndrome with important differences in response to therapy by left ventricular ejection fraction (LVEF), existing risk stratification models typically group all HF patients together. The relative importance of common predictor variables for important clinical outcomes across strata of LVEF is relatively unknown.
  
  
  RESULTS
  We identified all members with HF between 2005 and 2008 from 4 integrated healthcare systems in the Cardiovascular Research Network. LVEF was categorized as preserved (LVEF ≥ 50% or normal), borderline (41%-49% or mildly reduced), and reduced (≤ 40% or moderately to severely reduced). We used Cox regression models to identify independent predictors of death and hospitalization by LVEF category. Among 30094 ambulatory adults with HF, mean age was 74 years and 46% were women. LVEF was preserved in 49.5%, borderline in 16.2%, and reduced in 34.3% of patients. During a median follow-up of 1.8 years (interquartile range, 0.8-3.1), 8060 (26.8%) patients died, 8108 (26.9%) were hospitalized for HF, and 20272 (67.4%) were hospitalized for any reason. In multivariable models, nearly all tested covariates performed similarly across LVEF strata for the outcome of death from any cause, as well as for HF-related and all-cause hospitalizations.
  
  
  CONCLUSIONS
  We found that in a large, diverse contemporary HF population, risk assessment was strikingly similar across all LVEF categories. These data suggest that, although many HF therapies are uniquely applied to patients with reduced LVEF, individual prognostic factor performance does not seem to be significantly related to level of left ventricular systolic function.
authors.affiliation: Institute for Health Research, Kaiser Permanente Colorado, Denver, CO, USA. larry.allen@ucdenver.edu
authors.forename: Larry A
authors.initials: LA
authors.lastname: Allen
authors.forename: David J
authors.initials: DJ
authors.lastname: Magid
authors.forename: Jerry H
authors.initials: JH
authors.lastname: Gurwitz
authors.forename: David H
authors.initials: DH
authors.lastname: Smith
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Goldberg
authors.forename: Jane
authors.initials: J
authors.lastname: Saczynski
authors.forename: Micah L
authors.initials: ML
authors.lastname: Thorp
authors.forename: Grace
authors.initials: G
authors.lastname: Hsu
authors.forename: Sue Hee
authors.initials: SH
authors.lastname: Sung
authors.forename: Alan S
authors.initials: AS
authors.lastname: Go
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000503:physiopathology*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D013318:Stroke Volume; D016896:Treatment Outcome; D016277:Ventricular Function, Left
keywords: heart failure; outcomes assessment (health care); prognosis; risk factors