Abstract 18888: Long-Term (10 Years) Experience of Implantable Cardioverter-Defibrillator Implantation in Patients with Hypertrophic Cardiomyopathy
Introduction: Sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM) is unpredictable and the most frequent cause of premature death. Implantable cardioverter-defibrillator (ICD) therapy is an effective strategy for both primary and secondary SCD prevention in select HCM populations. However, limited data exist on the long-term follow-up of HCM patients with ICD for prevention of SCD.
Methods: We examined consecutive patients with HCM who underwent ICD implantation at our tertiary care institution. Patients were grouped into two cohorts (A and B) based on established clinical risk markers for SCD in HCM. Patients in group A had 2 or more major risk factors (≥2RF); patients in group B had 1 or fewer risk factors (≤1RF) for SCD. The number of appropriate and inappropriate ICD shocks, all-cause mortality and early and late ICD-related complications were compared between the two groups.
Results: Over a 10-year period, we identified 60 consecutive HCM patients (median age 52 years [interquartile range = 45-62]; 47% female) who underwent ICD implantation. Of these, 26 patients had ≥2RF (group A); 34 patients had ≤1 RF (group B). Median follow-up was 62 months for both groups. In group A, 30.8% of HCM patients (8 of 26) received an appropriate ICD shock compared to 2.9% of patients in group B (1 of 34) (p= 0.004). Also, only 2 patients (7.7%) in group A received an inappropriate ICD shock compared with 6 patients (17.6%) in group B (p=0.446). The predominant risk predictors for ICD shocks in both groups were nonsustained ventricular tachycardia on Holter monitor and history of syncope. There were no differences between groups for early and late ICD-related complications of pneumothorax, pocket hematoma, infection, lead revisions, symptomatic upper-extremity deep venous thrombosis, new atrial arrhythmias and generator changes. All-cause mortality was not statistically significant between the groups (15.4% in group A compared to 12.1% in group B (p=0.717).
Conclusion: Hypertrophic cardiomyopathy patients with 2 or more risk factors for SCD are more likely to receive an appropriate ICD shock compared to patients with 1 or fewer risk factors. This study validates that HCM patients with at least two risk factors for SCD benefit most with ICD implantation.
- © 2012 by American Heart Association, Inc.