title: Implantable cardioverter-defibrillators in hypertrophic cardiomyopathy: patient outcomes, rate of appropriate and inappropriate interventions, and complications.
abstract: BACKGROUND
  Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM), but this can be prevented by an implantable cardioverter-defibrillator (ICD). The aim of this study is to evaluate HCM patients with ICDs for primary or secondary prevention of SCD.
  
  
  METHODS
  The study population consisted of all HCM patients with an ICD in 2 tertiary referral clinics. End points during follow-up were total and cardiac mortality, appropriate and inappropriate ICD intervention, and device-related complications. Cox-regression analysis was performed to identify predictors of outcome.
  
  
  RESULTS
  ICDs were implanted in 134 patients with HCM (mean age 44 ± 17 years, 34% women, 4.2 ± 4.8 years follow-up). Annualized cardiac mortality rate was 3.4% per year and associated with New York Heart Association class III or IV (HR 5.2 [2.0-14, P = .002]) and cardiac resynchronization therapy (HR 6.3 [2.1-20, P = .02]). Appropriate ICD interventions occurred in 38 patients (6.8%/year) and was associated with implantation for secondary prevention of SCD (HR 4.0 [1.8-9.1], P = .001) and male gender (HR 3.3 [1.2-9.0], P = .02). Inappropriate ICD intervention occurred in 21 patients (3.7%/year) and in 20 patients device related complications were documented (3.6%/year).
  
  
  CONCLUSIONS
  ICDs successfully abort life-threatening arrhythmias in HCM patients at increased risk of SCD with an annualized intervention rate of 6.8% per year. End-stage heart failure is the main cause of mortality in these patients. The annualized rate of inappropriate ICD intervention was 3.7% per year, whereas device-related complications occurred 3.6% per year.
authors.affiliation: Department of Cardiology, Thoraxcenter, Erasmus MC, Postbus 2040, Rotterdam, The Netherlands.
authors.forename: Pieter A
authors.initials: PA
authors.lastname: Vriesendorp
authors.forename: Arend F L
authors.initials: AF
authors.lastname: Schinkel
authors.forename: Johan
authors.initials: J
authors.lastname: Van Cleemput
authors.forename: Rik
authors.initials: R
authors.lastname: Willems
authors.forename: Luc J L M
authors.initials: LJ
authors.lastname: Jordaens
authors.forename: Dominic A M J
authors.initials: DA
authors.lastname: Theuns
authors.forename: Marjon A
authors.initials: MA
authors.lastname: van Slegtenhorst
authors.forename: Thomy J
authors.initials: TJ
authors.lastname: de Ravel
authors.forename: Folkert J
authors.initials: FJ
authors.lastname: ten Cate
authors.forename: Michelle
authors.initials: M
authors.lastname: Michels
mesh_terms: D000328:Adult; D058406:Cardiac Resynchronization Therapy / Q000706:statistics & numerical data*; D002312:Cardiomyopathy, Hypertrophic / Q000401:mortality / Q000628:therapy*; D016757:Death, Sudden, Cardiac / Q000209:etiology* / Q000517:prevention & control; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome