December 30, 2012Circulation Arrhythmia and Electrophysiology95 citationsOpen Access
The ICD for Primary Prevention in Patients With Inherited Cardiac Diseases
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Key Result
ICD implantation for primary prevention yielded appropriate shock rates of 4.2-6.7/100 patient-years in ARVC and HCM, but approached zero in other conditions, with a 35% overall adverse event rate.
Key Points
- This research aims to determine the effectiveness and risk associated with ICD implantations for primary versus secondary prevention in inherited cardiac diseases.
- Evaluated 354 patients with inherited cardiac diseases treated with ICDs between 1993 and 2011.
- Measured incidence rates of appropriate shocks in primary and secondary prevention groups for respective cardiac conditions.
- The incidence rate of appropriate shocks was 4.2 to 6.7/100 patient-years for primary prevention patients with arrhythmogenic right ventricular cardiomyopathy and hypertrophic cardiomyopathy.
- For primary prevention patients with Brugada syndrome and long QT syndrome, the risk for appropriate shocks approached zero.
- 35% of patients (123 individuals) experienced ICD-related adverse events.
Study Design
Type
Cohort (n=354)
Structured PICO
Does ICD implantation for primary prevention compared to secondary prevention affect the incidence of appropriate shocks in patients with inherited cardiac diseases?
P
Population
354 patients with inherited cardiac diseases treated with ICDs between 1993 and 2011.
E
Exposure
Implantable cardioverter-defibrillator (ICD) for primary prevention
C
Comparator
Implantable cardioverter-defibrillator (ICD) for secondary prevention
O
Outcome
Incidence rate of appropriate shockshard clinical
Primary prevention ICDs in primary electrical diseases (Brugada, LQTS, DPP6) yield near-zero appropriate shocks but carry a 35% risk of adverse events, highlighting a poor risk-benefit ratio compared to structural cardiomyopathies.
Abstract
BACKGROUND: Indications for prophylactic implantable cardioverter-defibrillator (ICD) therapy in patients with inherited cardiac diseases stem from observational studies and are uncertain. This study evaluates the efficacy and harm rate of ICD implantations for primary prevention compared with secondary prevention in inherited cardiac diseases. METHODS AND RESULTS: Between January 1, 1993, and April 1, 2011, 354 patients with inherited cardiac diseases were treated with ICDs. Incidence rates of appropriate shocks in primary prevention patients with arrhythmogenic right ventricular cardiomyopathy and hypertrophic cardiomyopathy were 4.2 to 6.7/100 patient-years, whereas the risk for appropriate shocks in primary prevention patients with Brugada syndrome, long QT syndrome, or carrying the DPP6 haplotype approached zero. Conversely, in secondary prevention patients there was a considerably higher incidence rate of appropriate shocks. None of the indications for primary prevention were associated with appropriate shock therapy. One hundred twenty-three patients (35%) experienced ICD-related adverse events. CONCLUSIONS: For Brugada syndrome, long QT syndrome, and DPP6 the efficacy of an ICD for primary prevention contrasts with the amount of harm, and factors that formed the indication for ICD implantation do not relate to the occurrence of appropriate shocks. The higher appropriate discharge rates in arrhythmogenic right ventricular cardiomyopathy and hypertrophic cardiomyopathy compared with primary electric diseases might result from a more advanced risk stratification scheme in these inherited cardiomyopathies.
Cite This Study
Nordkamp et al. (2012) conducted a cohort in Inherited cardiac diseases (n=354). ICD implantation for primary prevention vs. ICD implantation for secondary prevention was evaluated on Incidence rates of appropriate shocks. ICD implantation for primary prevention yielded appropriate shock rates of 4.2-6.7/100 patient-years in ARVC and HCM, but approached zero in other conditions, with a 35% overall adverse event rate.