title: Real world effectiveness of primary implantable cardioverter defibrillators implanted during hospital admissions for exacerbation of heart failure or other acute co-morbidities: cohort study of older patients with heart failure.
abstract: OBJECTIVE
  To examine the effectiveness of primary implantable cardioverter defibrillators (ICDs) in elderly patients receiving the device during a hospital admission for exacerbation of heart failure or other acute co-morbidities, with an emphasis on adjustment for early mortality and other factors reflecting healthy candidate bias rather than the effect of the ICD.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Linked data from the Centers for Medicare and Medicaid Services and American College of Cardiology-National Cardiovascular Data Registry ICD registry, nationwide heart failure registry, and Medicare claims data 2004-09.
  
  
  METHODS
  23,111 patients aged ≥ 66 who were admitted to hospital for exacerbation of heart failure or other acute co-morbidities and eligible for primary ICDs.
  
  
  METHODS
  All cause mortality and sudden cardiac death. Latency analyses with Cox regression were used to derive crude hazard ratios and hazard ratios adjusted for high dimension propensity score for outcomes after 180 days from index implantation or discharge.
  
  
  RESULTS
  Patients who received an ICD during a hospital admission had lower crude mortality risk than patients who did not receive an ICD (40% v 60% at three years); however, with conditioning on 180 day survival and with adjustment for high dimension propensity score, the apparent benefit with ICD was no longer evident for sudden cardiac death (adjusted hazard ratio 0.95, 95% confidence interval 0.78 to 1.17) and had a diminished impact on total mortality (0.91, 0.82 to 1.00). There were trends towards a benefit with ICD in reducing mortality or sudden cardiac death in patients who had had a myocardial infarction more than 40 days previously, left bundle branch block, or low serum B type natriuretic peptide; however, these trends did not reach significance.
  
  
  CONCLUSIONS
  After adjustment for healthy candidate bias and confounding, the benefits of primary ICD therapy seen in pivotal trials were not apparent in patients aged 66 or over who received ICDs during a hospital admission for exacerbation of heart failure or other acute co-morbidities. Future research is warranted to further identify subgroups of elderly patients who are more likely to benefit from ICDs. Recognition of those patients whose dominant risk factors are from decompensated heart failure and non-cardiac co-morbidities will allow better focus on ICDs in those patients for whom the device offers the most benefit and provides meaningful prolonging of life.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA.
authors.forename: Chih-Ying
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Lynne Warner
authors.initials: LW
authors.lastname: Stevenson
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Garrick C
authors.initials: GC
authors.lastname: Stewart
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Deepak L
authors.initials: DL
authors.lastname: Bhatt
authors.affiliation: Quantitative Sciences Unit, Stanford University School of Medicine, Palo Alto, CA 94305, USA.
authors.forename: Manisha
authors.initials: M
authors.lastname: Desai
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Seeger
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Williams
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA.
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Jalbert
authors.affiliation: Duke Clinical Research Institute, Durham, NC 27705, USA soko.setoguchi@duke.edu.
authors.forename: Soko
authors.initials: S
authors.lastname: Setoguchi
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000628:therapy; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D008297:Male; D006278:Medicare; D018579:Patient Selection; D057216:Propensity Score; D012042:Registries; D012189:Retrospective Studies; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology