title: Incidence of Implantable Cardioverter Defibrillator Therapy and Mortality in Primary and Secondary Prevention of Sudden Cardiac Death.
abstract: BACKGROUND
  Implantable cardioverter defibrillators (ICDs) reduce mortality in patients implanted for primary and secondary prevention of sudden cardiac death. Data on the incidence of appropriate ICD therapies in primary vs. secondary prevention are limited.
  
  
  OBJECTIVE
  To compare ICD therapies and mortality in primary vs. secondary prevention of sudden cardiac death.
  
  
  METHODS
  We conducted a retrospective analysis of 581 consecutive patients receiving an ICD for primary (66%) or secondary (34%) prevention indications.
  
  
  RESULTS
  During long-term follow-up, 29% of patients implanted for secondary prevention received appropriate ICD therapy vs. 18% implanted for primary prevention. However, the overall 7 year mortality rate was not significantly different between the two groups (26.9%, P = 0.292). Multivariate analysis showed that patients implanted for primary prevention had a significantly lower risk of appropriate ICD therapy even after adjustment for age, left ventricular ejection fraction < 0.35 and chronic renal failure (HR 1.63, 95% CI 1.10-2.41, P = 0.015).
  
  
  CONCLUSIONS
  Patients implanted for secondary prevention were more likely to receive appropriate ICD therapy, with a significantly shorter time period from ICD implant to the first therapy. However, all-cause mortality was comparable between primary and secondary prevention groups.
authors.forename: Yuval
authors.initials: Y
authors.lastname: Konstantino
authors.forename: Tali
authors.initials: T
authors.lastname: Shafat
authors.forename: Victor
authors.initials: V
authors.lastname: Novack
authors.forename: Lena
authors.initials: L
authors.lastname: Novack
authors.forename: Guy
authors.initials: G
authors.lastname: Amit
mesh_terms: D000368:Aged; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011322:Primary Prevention / Q000379:methods*; D012189:Retrospective Studies; D055502:Secondary Prevention / Q000379:methods*; D013997:Time Factors