title: Age differences in primary prevention implantable cardioverter-defibrillator use in U.S. individuals.
abstract: OBJECTIVE
  To estimate the potentially inappropriate use of implantable cardioverter-defibrillator ICDs in older U.S. adults.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  The National Cardiovascular Data ICD Registry.
  
  
  METHODS
  Forty-four thousand eight hundred five individuals in the National Cardiovascular Data's ICD Registry(™) who had received ICDs for primary prevention from January 2006 to December 2008. Individuals with a prior myocardial infarction and ejection fraction less than 30% were included.
  
  
  METHODS
  Mortality risk was categorized using the Multicenter Automatic Defibrillator Implantation (MADIT) II risk-stratification system. Low-risk and very-high-risk individuals were considered potentially inappropriate recipients.
  
  
  RESULTS
  Of 44,805 individuals, 67% (n = 29,893) were aged 65 and older, of whom 51% were aged 75 and older. A significant proportion of ICD recipients had a low risk of death (16%, n = 6,969) or very high risk of nonarrhythmic death (8%, n = 3,693). Potentially inappropriate ICD use was 10% in those aged 75 and older, much less than in younger groups (40%, <65; 21%, 65-74, P < .001). Although age was associated with a high risk of nonarrhythmic death, its influence was markedly attenuated after adjusting for comorbidities and timing of ICD implantation (odds ratio = 1.02, 95% confidence interval = 1.02-1.03, P < .001).
  
  
  CONCLUSIONS
  Potentially inappropriate ICD use appears significantly less--and at modest rates--in older Americans than in younger age groups. Overall, almost one-quarter of individuals may have received ICDs inappropriately based on their risk of death. Physicians appear to be conservatively referring older adults and wisely deferring those with high comorbid burden.
authors: School of Medicine, Stanford University Stanford, California 94305, USA. vtsai@stanford.edu
authors: Vivian
authors: V
authors: Tsai
authors: Mary K
authors: MK
authors: Goldstein
authors: Henry H
authors: HH
authors: Hsia
authors: Yongfei
authors: Y
authors: Wang
authors: Jeptha
authors: J
authors: Curtis
authors: Paul A
authors: PA
authors: Heidenreich
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000601:surgery*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D019300:Medical Errors / Q000706:statistics & numerical data*; D008875:Middle Aged; D011322:Primary Prevention; D012189:Retrospective Studies; D018570:Risk Assessment; D014481:United States