The clinical management of relatives of young sudden unexplained death victims; implantable defibrillators are rarely indicated

Objective Following national guidance on management of sudden unexplained death (SUD) in the young, inherited cardiac conditions (ICC) clinics were established to identify and treat relatives thought to be at increased risk. Studies have examined diagnostic yield of these clinics but outcome of clinical management has not been reported.

Design Observational outcome study of consecutively referred relatives of SUD victims.

Setting Regional ICC clinic.

Patients 193 individuals (108 families) referred to a regional ICC clinic following SUD/aborted cardiac arrest of a young relative (mean follow-up 16.5 months, range 0.1–61).

Interventions All individuals underwent assessment by history, examination, ECG and echocardiography. Exercise electrocardiography, ajmaline provocation, further imaging techniques and genetic testing were performed in selected individuals. Implantable cardioverter-defibrillator (ICD) insertion based on national guidelines.

Main outcome measures and results Forty-five patients (23%) from 38 families (35%) were diagnosed with an inheritable cause of sudden death. Eighteen had potentially prognostically important medication commenced and 4 had an ICD inserted on clinic recommendation (2 hypertrophic cardiomyopathy, 1 dilated cardiomyopathy, 1 arrhythmogenic right ventricular cardiomyopathy). Two other individuals had ICDs removed after negative testing for familial RYR2 mutations. No deaths have occurred during follow-up to date.

Conclusion A diagnosis of an inheritable cause of sudden death was obtained in a significant minority of those with a family history of SUD/aborted cardiac arrest. The number of ICDs inserted as a result of specialist assessment was very small (2%). A major function of the clinic is reassurance of the clinically normal and cessation of treatment after exclusion of familial disease by genetic testing.