Scope and nature of sudden cardiac death before age 40 in Ontario: A report from the Cardiac Death Advisory Committee of the Office of the Chief Coroner

BackgroundUnderstanding sudden cardiac death in the young may inform prevention strategies.ObjectiveTo determine the scope and nature of sudden death in a geographically defined population.MethodsWe performed a retrospective population-based cohort study in Ontario, Canada, of all sudden cardiac death cases involving persons aged 2–40 years identified from the 2008 comprehensive Coroner database. Of 1741 Coroner’s cases, 376 were considered potential sudden cardiac death cases and underwent review.ResultsThere were 174 cases of adjudicated sudden cardiac death from a population of 6,602,680 persons aged 2–40 years. Structural heart disease was present in 126 cases (72%), 78% of which was unrecognized. There was no identifiable cause of death in 48 cases (28%), representing primary arrhythmia syndromes. The majority of decedents were men (76%) over the age of 18 (90%). The overall incidence of sudden cardiac death increased with age from 0.7/100,000 (2–18 years) to 2.4/100,000 (19–29 years) to 5.3/100,000 (30–40 years) person-years. Persons experiencing sudden cardiac death before age 30 were more likely to have a primary arrhythmia syndrome (odds ratio 2.97; P<.001). The majority of events occurred in the home (72%); 33% of the events in children/adolescents and 9% of the events in adults occurred during reported moderate or vigorous exercise (P = .002). There were no pediatric deaths during organized competitive sports.ConclusionsThe incidence of sudden cardiac death increases with age, typically occurring in a man at rest in the home with unrecognized underlying heart disease or a primary arrhythmia syndrome. Prevention strategies should consider targeting identification of unrecognized structural heart disease and primary arrhythmia syndromes.