INTRODUCTION: Although implantable cardioverter-defibrillators (ICDs) are used 
in sudden cardiac death (SCD) prevention in high-risk patients with hypertrophic 
cardiomyopathy (HCM), long-term results as well as precise risk stratification 
are discussed in a limited number of reports. The aim of the study was to assess 
the incidence of ICD intervention in HCM patients with relation to clinical risk 
profile.
METHODS AND RESULTS: We studied 104 consecutive patients with HCM implanted in a 
single center. The mean age of study population was 35.6 (SD, 16.2) years with 
the average follow-up of 4.6 (SD, 2.6) years. ICD was implanted for secondary (n 
= 26) and primary (n = 78) prevention of SCD. In the secondary prevention group, 
14 patients (53.8%) experienced at least 1 appropriate device intervention 
(7.9%/year). In the primary prevention (PP) group appropriate ICD discharges 
occurred in 13 patients (16.7%) and intervention rate was 4.0%/year. 
Nonsustained VT was the only predictive risk factor (RF) for an appropriate ICD 
intervention in the PP (positive predictive value 22%, negative predictive value 
96%). No significant difference was observed in the incidence of appropriate ICD 
discharges between PP patients with 1, 2, or more RF. Complications of the 
treatment included: inappropriate shocks (33.7%), lead dysfunction (12.5%), and 
infections: 4.8% of patients. Four patients died during follow-up.
CONCLUSION: ICD therapy is effective in SCD prevention in patients with HCM, 
although the complication rate is significant. Nonsustained ventricular 
tachycardia seems to be the most predictive RF for appropriate device 
discharges. Number of RF did not impact the incidence of appropriate ICD 
interventions.