title: Application of a mortality risk score in a general population of patients with an implantable cardioverter defibrillator (ICD).
abstract: OBJECTIVE
  The implantable cardioverter defibrillator (ICD) is very effective in the prevention of sudden cardiac death, but its benefit is impaired by competing risks. A simple risk model to predict mortality was designed for patients with primary prevention and ischaemic cardiomyopathy. We aimed to apply this score to a general ICD population.
  
  
  METHODS
  This retrospective registry study included all patients in whom an ICD was implanted at a tertiary referral hospital. Risk factors were age >70 years, QRS width >120 ms, atrial fibrillation, New York Heart Association Functional Classification class >2 and glomerular filtration rate <60 mL/min/1.73 m(2). Kaplan-Meier curves were constructed according to the presence of 0, 1, 2 and >2 risk factors.
  
  
  RESULTS
  The cohort consists of 1032 patients, 881 (86%) were men, mean age was 61±14 years and mean follow-up 66±46 months. 256 patients (25%) died 58±41 months after implant. The setting was secondary prevention in 498 patients (48%). No risk factors was present in 32% of patients, 1 in 27%, 2 in 20% and >2 in 21%, respectively. There was a significant and comprehensible relation between risk score and mortality. Cumulative survival was 82% in patients with 0 risk factors, 63% in those with 1, 41% in those with 2 and 23% in those with >2 risk factors (p < 0.0001). ICD therapies were documented in 421 patients (41%) without correlation to risk factors.
  
  
  CONCLUSIONS
  In a mixed population of primary and secondary preventive ICD carriers, application of a simple risk score predicts long-term mortality but not appropriate use of the ICD.
authors.affiliation: Department of Cardiology, University of Basel Hospital, , Basel, Switzerland.
authors.forename: Beat A
authors.initials: BA
authors.lastname: Schaer
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kühne
authors.forename: David
authors.initials: D
authors.lastname: Blatter
authors.forename: Stefan
authors.initials: S
authors.lastname: Osswald
authors.forename: Christian
authors.initials: C
authors.lastname: Sticherling
mesh_terms: D000368:Aged; D016757:Death, Sudden, Cardiac / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D055502:Secondary Prevention / Q000379:methods*; D015996:Survival Rate / Q000639:trends; D013557:Switzerland / Q000453:epidemiology; D017180:Tachycardia, Ventricular / Q000150:complications / Q000401:mortality / Q000628:therapy*
keywords: Implantable cardioverter defibrillator; sudden cardiac death; ventricular fibrillation; ventricular tachycardia