title: Use and long-term outcomes of implantable cardioverter-defibrillators, 1990 to 2009.
abstract: BACKGROUND
  Automated implantable cardioverter-defibrillators (ICDs) have become standard therapy for patients at high risk for sudden cardiac death. Linked data allow examination of trends in use and long-term survival after ICD implantation in an adult population.
  
  
  METHODS
  Linked state-wide person-based data on hospital admissions and deaths from 1980 to 2009 were used to identify incident cases of ICD implantation. Population rates were calculated using census data. Kaplan-Meier techniques were used to describe cumulative survival. Cox regression models were used to determine the factors associated with the outcomes.
  
  
  RESULTS
  Between 1988 and 2009, 1593 devices were implanted in patients in Western Australia, rising from 2 in 1988 to 245 in 2009; standardized population rates rose from 0.8 in 100000 in 1995 to 14.9 in 100000 in 2009. Mean age rose from 52.6 (SD 11.6) to 64.1 (11.4) years. Ventricular tachycardia (23%), cardiomyopathy (18%), and heart failure (16%) were the most frequent principal diagnoses. Ischemic heart disease was present in 49% of patients. Five-year cumulative survival was 0.74 (SE 0.01), and at 10 years, 0.53 (SE 0.03); median survival was 11.3 years. Readmission within a year, older age, heart failure, device complications, and chronic ischemic heart disease were associated with poorer survival.
  
  
  CONCLUSIONS
  Implantable cardioverter-defibrillator use in adults at risk for sudden cardiac death has grown rapidly. Readmission within 12 months of discharge is associated with worse medium and long-term mortality. Survival for most patients younger than 65 years exceeds 10 years and 5 years for those aged ≥75 years.
authors.affiliation: School of Population Health, University of Western Australia, Perth, Western Australia. pamela.bradshaw@uwa.edu.au
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Bradshaw
authors.forename: Paul
authors.initials: P
authors.lastname: Stobie
authors.forename: Tom
authors.initials: T
authors.lastname: Briffa
authors.forename: Michael S T
authors.initials: MS
authors.lastname: Hobbs
mesh_terms: D016757:Death, Sudden, Cardiac / Q000453:epidemiology* / Q000517:prevention & control*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D017180:Tachycardia, Ventricular / Q000401:mortality / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D014904:Western Australia / Q000453:epidemiology