Diagnostic findings and follow-up outcomes in relatives to young non-autopsied sudden death victims.

Background: Guidelines recommend clinical assessment of relatives to young sudden cardiac death (SCD) victims in case the SCD was due to an inherited cardiac disorder. Work-up of relatives is guided by findings in the SCD victim. If post-mortem examinations have not been performed the work-up of relatives is challenged.

Method: In this retrospective study we included families referred to our tertiary referral centre between 2005 and 2018 due to a possible SCD (pSCD) in the family. Autopsy had not been performed in any of the pSCD victims. The relatives underwent cardiac work-up focusing on putative presence of inherited cardiac disorders and genetic analysis in selected cases. A family diagnosis was only established if≥1 relative was diagnosed. The families were categorised as: 1) definite inherited cardiac diagnosis, 2) borderline diagnosis, or 3) undiagnosed.

Results: We assessed 149 relatives (43 ± 16 years, 48% men) from 84 pSCD non-autopsied cases (44 ± 11 years, 79% men). In 11 (13%) families a definite inherited cardiac diagnosis was established, a borderline diagnosis in 8 (10%) families, and 65 (77%) families remained undiagnosed. One third of the diagnosed relatives were offered pharmaco- or device-based therapy. During follow-up for 4.7 ± 3.6 years no relatives from the families with definite diagnoses died. No events were seen in the groups with borderline or no diagnoses.

Conclusion: The diagnostic yield and need for treatment in diagnosed relatives warrant work-up, also of families with non-autopsied pSCD victims. No or reduced follow-up of relatives without signs or symptoms of heart diseases may be safe.