German WCD Study

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Experience With the Wearable Cardioverter-Defibrillator in Patients at High Risk for Sudden Cardiac Death


  • This nonrandomized, observational study was designed to provide data on the use and effectiveness of the wearable cardioverter defibrillator (WCD) in preventing sudden cardiac death (SCD) caused by ventricular tachyarrhythmia (VT) or ventricular fibrillation (VF).


  • Retrospective study of 6,043 German patients (median age = 57 years, male = 78.5%) prescribed a WCD from April 2010 through October 2013.
  • Included patients with non-ischemic cardiomyopathy (59.1%)*, ischemic cardiomyopathy (26.9%), ICD explants (11.9%), genetic heart disease (1.4%), and heart transplants (0.7%).

Key Results

  • SCD risk is high in the early period following an acute cardiac event – 89% of treatments occurred within the first 90 days after the event.
  • Overall, 94% of treated patients were successfully converted into a slower heart rhythm.
  • Survival 24 hours after treatment shock was 93%.
  • Inappropriate shock rate was very low (0.4%).
  • Patient wear time with the WCD was high – median daily use was 23.1 hours.


  • Study results confirm that the WCD is safe and effective in protecting patients with a low ejection fraction (≤ 35%) from SCD.
  • The results of the study support the German Cardiology Association and the European Society of Cardiology’s recommendations for use in patients who are at high risk of SCD.


*Includes patients with new diagnosis for dilated cardiomyopathy, congestive heart failure, and myocarditis

Click here to read the full publication
Waessnig N, Guenther M, Quick S, et al. Experience with the wearable cardioverter-defibrillator in patients at high risk for sudden cardiac death. Circulation 2016;134:635–643.  

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