title: Association between prophylactic implantable cardioverter-defibrillators and survival in patients with left ventricular ejection fraction between 30% and 35%.
abstract: OBJECTIVE
  Clinical trials of prophylactic implantable cardioverter-defibrillators (ICDs) have included a minority of patients with a left ventricular ejection fraction (LVEF) between 30% and 35%. Because a large number of ICDs in the United States are implanted in such patients, it is important to study survival associated with this therapy.
  
  
  OBJECTIVE
  To characterize patients with LVEF between 30% and 35% and compare the survival of those with and without ICDs.
  
  
  METHODS
  Retrospective cohort study of Medicare beneficiaries in the National Cardiovascular Data Registry ICD registry (January 1, 2006, through December 31, 2007) with an LVEF between 30% and 35% who received an ICD during a heart failure hospitalization and similar patients in the Get With The Guidelines-Heart Failure (GWTG-HF) database (January 1, 2005, through December 31, 2009) with no ICD. The analysis was repeated in patients with an LVEF less than 30%. There were 3120 patients with an LVEF between 30% and 35% (816 in matched cohorts) and 4578 with an LVEF less than 30% (2176 in matched cohorts). Propensity score matching and Cox models were applied.
  
  
  METHODS
  The primary outcome was all-cause mortality; data were obtained from Medicare claims through December 31, 2011.
  
  
  RESULTS
  There were no significant differences in the baseline characteristics of the matched groups (n = 408 for both groups). Among patients with an LVEF between 30% and 35%, there were 248 deaths in the ICD Registry group, within a median follow-up of 4.4 years (interquartile range, 2.7-4.9) and 249 deaths in the GWTG HF group, within a median follow-up of 2.9 years (interquartile range, 2.1-4.4). The risk of all-cause mortality in patients with an LVEF between 30% and 35% and an ICD was significantly lower than that in matched patients without an ICD (3-year mortality rates: 51.4% vs 55.0%; hazard ratio, 0.83 [95% CI, 0.69-0.99]; P = .04). Presence of an ICD also was associated with better survival in patients with an LVEF less than 30% (3-year mortality rates: 45.0% vs 57.6%; 634 and 660 total deaths; hazard ratio, 0.72 [95% CI, 0.65-0.81]; P < .001) (P = .20 for interaction).
  
  
  CONCLUSIONS
  Among Medicare beneficiaries hospitalized for heart failure and with an LVEF between 30% and 35% and less than 30%, survival at 3 years was better in patients who received a prophylactic ICD than in comparable patients with no ICD. These findings support guideline recommendations to implant prophylactic ICDs in eligible patients with an LVEF of 35% or less.
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina3Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Sana M
authors.initials: SM
authors.lastname: Al-Khatib
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Anne S
authors.initials: AS
authors.lastname: Hellkamp
authors.affiliation: Ahmanson-UCLA Cardiomyopathy Center, Ronald Reagan-UCLA Medical Center, Los Angeles, California.
authors.forename: Gregg C
authors.initials: GC
authors.lastname: Fonarow
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina3Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Mark
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina2Center for Clinical and Genetic Economics, Department of Medicine, Duke University Medical Center, Durham, North Carolina4Division of General.
authors.forename: Lesley H
authors.initials: LH
authors.lastname: Curtis
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina3Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Hernandez
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Anstrom
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina3Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Peterson
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Gillian D
authors.initials: GD
authors.lastname: Sanders
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Hussein R
authors.initials: HR
authors.lastname: Al-Khalidi
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Bradley G
authors.initials: BG
authors.lastname: Hammill
authors.affiliation: Stanford University, Palo Alto Veteran's Health Care System, Palo Alto, California.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heidenreich
authors.affiliation: Duke Clinical Research Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina2Center for Clinical and Genetic Economics, Department of Medicine, Duke University Medical Center, Durham, North Carolina7Mayo Clinic, Rochest.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Hammill
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data; D057216:Propensity Score; D012042:Registries; D012189:Retrospective Studies; D012306:Risk; D016019:Survival Analysis; D014481:United States; D018487:Ventricular Dysfunction, Left; D016277:Ventricular Function, Left