BACKGROUND: Cardiac arrest may be the first manifestation in the majority of inherited cardiac diseases. International guidelines recommend screening of relatives of Sudden Cardiac Arrest (SCA) survivors if an inherited cardiac disorder is suspected.

OBJECTIVE: To assess the prevalence and spectrum of inherited cardiac diseases and the long-term outcome in a consecutive cohort of non-ischemic SCA survivors (probands) and their relatives.

METHODS: This retrospective study consecutively included probands and their relatives referred to our tertiary center for family screening between 2005-2018. All participants underwent a systematic work-up and follow-up protocol. Data were retrieved from medical records.

RESULTS: We included 155 probands (age 41.2±15.5 years, 61% male) and 282 relatives (age 35.7±18.8 years, 51% male). Mean follow-up was 7.1 years for probands and 4.4 years for relatives. We identified an inherited cardiac disease in 76 (49%) probands, and in 42 (15%) relatives. An ICD was implanted in 147 (95%) probands and in nine (3%) relatives. During follow-up four (3%) probands and three (1%) relatives died, and 37 probands and two relatives received appropriate shock therapy. All relatives received genetic counseling and 18 (6%) relatives started pharmacological treatment during follow-up.

CONCLUSION: Systematic work-up of non-ischemic SCA survivors and their relatives identified an inherited cardiac disease in 49% of referred probands and 15% of their relatives. The favorable long-term prognosis of diagnosed relatives probably not only reflects lower age, but also the effects of early diagnosis, treatment and follow-up. These findings support systematic work-up of SCA survivors and their relatives.