Implantable cardioverter-defibrillators in hypertrophic cardiomyopathy: patient outcomes, rate of appropriate and inappropriate interventions, and complications

Am Heart J. 2013 Sep;166(3):496-502. doi: 10.1016/j.ahj.2013.06.009. Epub 2013 Jul 16.


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).

Conclusion: 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.

MeSH terms

  • Adult
  • Cardiac Resynchronization Therapy / statistics & numerical data*
  • Cardiomyopathy, Hypertrophic / mortality
  • Cardiomyopathy, Hypertrophic / therapy*
  • Death, Sudden, Cardiac / etiology*
  • Death, Sudden, Cardiac / prevention & control
  • Defibrillators, Implantable / adverse effects*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Regression Analysis
  • Risk Assessment
  • Risk Factors
  • Treatment Outcome