Implantable cardioverter defibrillator use in arrhythmogenic right ventricular cardiomyopathy in North America and...

Area of Science:

• Cardiology
• Electrophysiology
• Genetic Heart Diseases

Background:

• Arrhythmogenic right ventricular cardiomyopathy (ARVC) poses a risk of sudden cardiac death (SCD).
• Implantable cardioverter-defibrillators (ICDs) are crucial for primary prevention of SCD in ARVC.
• Cross-continental variations in ICD utilization and outcomes in ARVC are not well-defined.

Purpose of the Study:

• To investigate geographical differences in primary prevention ICD implantation rates among ARVC patients.
• To compare survival free from sustained ventricular arrhythmia (VA) between North American and European ARVC cohorts.
• To analyze the impact of ICD utilization on VA event rates across different risk strata.

Main Methods:

• Retrospective analysis of ARVC patients without prior VA from European and North American clinical registries.
• Stratification of patients by predicted 5-year VA risk (low, intermediate, high).
• Assessment of differences in ICD implantation rates and time to first sustained VA event, including appropriate ICD therapy.

Main Results:

• Over 1000 ARVC patients were followed for a median of 5.1 years; 50.5% received primary prevention ICDs.
• North American patients were >3 times more likely to receive ICDs (HR 3.1) but had only a mildly increased risk of sustained VA (HR 1.4).
• North Americans without ICDs had a higher risk of sustained VA (HR 2.1) compared to Europeans.

Conclusions:

• ARVC patients in North America received primary prevention ICDs significantly more often than those in Europe, across all risk levels.
• Lower ICD implantation rates in Europe were not associated with a higher incidence of VA events in patients without ICDs.
• Geographical disparities in ICD use for ARVC primary prevention warrant further investigation into underlying factors and clinical implications.