Cardiogenetic screening of first-degree relatives after sudden cardiac death in the young: a population-based approach

Aims To investigate the yield of cardiogenetic screening of relatives of young sudden cardiac death (SCD) and sudden unexplained death (SUD) victims in a population-based setting.

Methods and results A population-based study was carried out between 2000 and 2006. Records of the hospital, death declaration certificates, and resuscitation records were reviewed for SCD and SUD cases (1-40 years). Information on autopsy results and cardiogenetic screening of the victims' first-degree relatives was collected. Relatives were invited for additional cardiogenetic screening when this had not yet been performed. The search led to 16 cases of SCD/SUD and 4 cases of aborted SCD/SUD. Causes of SCD/SUD were myocardial infarction (n = 3), arrhythmogenic right ventricular cardiomyopathy (ARVC) (n = 2), long-QT syndrome (n = 1), hypertrophic cardiomyopathy (n = 2), left ventricular hypertrophy due to aortic stenosis (n = 1), and unknown cause of death (n = 7). Causes of aborted SCD/SUD were myocardial infarction (n = 2), idiopatic ventricular fibrillation (n = 1), and the Brugada syndrome (n = 1). The cardiogenetic screening of 37 relatives of 12 victims led to a diagnosis of Brugada syndrome in 3 relatives and the suspicion of ARVC in 2 relatives. The yield of screening of these relatives was 14% (95% confidence interval: 3-25%).

Conclusion In the usual care, relatives of (aborted) SCD and SUD victims are often not referred for cardiogenetic screening. Screening is often not performed according to a systematic approach, and the detection rate of inherited diseases in relatives of (aborted) SCD and SUD victims in a population-based setting, although substantial, is lower than expected based on previous studies.