Characterization of sudden death etiologies in a Portuguese population younger than 40 years-old

Abstract

Abstract Background The incidence and pathogenesis of sudden death (SD) in the young adult population in Portugal remains to be clarified. Some of the causes are known to be hereditary and a better understanding of these can have implications on the development of a national screening program for relatives of SD victims. Purpose To describe the leading causes of sudden cardiac and non-cardiac death in a young adult Portuguese population (≤40 years-old). Methods The authors retrospectively reviewed cases from a national database regarding individuals who underwent an autopsy, between 2012 and 2016, at 6 districts of mainland Portugal plus the islands. All young adults (1–40 years-old) who had a sudden unexpected death were included and violent deaths were excluded. This study was approved by the Institute Ethics Committee. We reviewed the autopsy files and collected demographic, clinical, necropsic, anatomopathological and toxicological data from each case. We performed statistical analysis using Stata 13.0 software. Results During a 5-year period, out of an estimated total of 2101 deaths in ages 1 to 40, 175 SD were identified. SD victims had a mean age of 32±9 years-old, the majority being of male gender (69%,n=120). There were 115 (66%) cases of SD of confirmed cardiac origin (see Table 1). The remaining causes were respiratory (18%), cerebral (7%), digestive (6%), endocrinologic (2%), urinary (1%), infectious (1%). The most frequent cardiac cause being coronary atherosclerosis (n=40,35%), which included lesions with estimated luminal narrowing >75% and/or documented type 1 acute myocardial infarction. These patients were older (31±8 vs 35±4, p<0.020), had a minimum age of 26 years, and more frequently male (85% vs 61%, p=0.011). There were 17 (15%) victims who had cardiopathy with histopathological hypertrophy (5 of them with associated fibrosis), and the diagnosis of hypertrophic cardiomyopathy (HCM) was possible in only 3 (3%) victims. In addition, there were 15 (13%) who died from pulmonary embolism who were predominantly women (23% vs 80%, p<0.001). There were 8 (7%) victims with a final diagnosis of cardiopathy with histopathological dilation, 2 possibly corresponding to post-partum cardiomyopathy (CMP), 1 to ethanolic CMP and 1 to ventricular dilation and fibrosis due to previous myocarditis, who had associated hepatitis with signs of activity. Six cases of acute myocarditis were identified, who were significantly younger, comparing to patients dying from other cardiac causes (23±13 vs 33±7, p=0,011). There were 2 cases of HCM with genetic data, one of which was complemented during molecular autopsy. Conclusions During a 5-year period, the cumulative incidence of SD in a region of Portugal is very low (n=175), cardiac causes being present in 66% of the cases. The most frequent cardiac cause is coronary atherosclerosis (35%). Funding Acknowledgement Type of funding sources: None.