This study demonstrates that LVNC is associated with a better prognosis than previously reported. In patients with familial disease, relatives may have features consistent with dilated cardiomyopathy rather than LVNC.

LVOTO is associated with an increased risk of SD/ICD that is related to the severity of obstruction and the presence of other recognized risk factors for SD. The low sudden death mortality in asymptomatic patients with LVOTO and no other SD risk markers suggests that aggressive interventions to reduce LVOTO are unwarranted in this group. Further studies are required to determine the most appropriate treatment strategies (ICD or gradient reduction) in patients with additional risk factors.

By using current diagnostic criteria, familial disease was present in 28% of index patients. A further 11% of their relatives had minor cardiac abnormalities, which, in the context of a disease whose mode of inheritance is autosomal dominant, are likely to represent early or mild disease expression. We advocate that the current ARVC diagnostic criteria are modified to reflect the broader spectrum of disease that is observed in family members.