Sudden death in young South European population: a cross-sectional study of postmortem cases.

To describe the annual incidence and the leading causes of sudden non-cardiac and cardiac death (SCD) in children and young adult Portuguese population. We retrospectively reviewed autopsy of sudden unexpected deaths reports from the Portuguese National Institute of Legal Medicine and Forensic Sciences' database, between 2012 and 2016, for the central region of Portugal, Azores and Madeira (ages 1-40: 26% of the total population). During a 5-year period, 159 SD were identified, corresponding to an annual incidence of 2,4 (95%confidence interval, 1,5-3,6) per 100.000 people-years. Victims had a mean age of 32 ± 7 years-old, and 72,3% were male. There were 70,4% cardiac, 16,4% respiratory and 7,5% neurologic causes of SD. The most frequent cardiac anatomopathological diagnosis was atherosclerotic coronary artery disease (CAD) (33,0%). There were 15,2% victims with left ventricular hypertrophy, with a diagnosis of hypertrophic cardiomyopathy only possible in 2,7%. The prevalence of cardiac pathological findings of uncertain significance was 30,4%. In conclusion, the annual incidence of SD was low. Atherosclerotic CAD was diagnosed in 33,0% victims, suggesting the need to intensify primary prevention measures in the young. The high prevalence of pathological findings of uncertain significance emphasizes the importance of molecular autopsy and screening of first-degree relatives.