Pulmonary embolism (PE) may debut as sudden death (SD) in young and middle-aged adults. This study aims to determine the epidemiological and clinicopathological characteristics involved in SD due to PE in this age group and the underlying risk factors.

Multicenter retrospective noncontrolled study based on forensic autopsies performed in individuals aged 12 to 49 years at 3 forensic pathology services in Spain (Valencia, Biscay, and Seville) over an 8-year period (2010-2017).

A total of 1344 cardiac SD cases were recorded, of which 128 (9.5%) were due to PE (57% male, median age 42 years). The annual incidence was 0.56/100 000 inhabitants/y. The main risk factor was obesity (62%; 18.5% morbid obesity). The mean body mass index was 34.9±13.1. Psychiatric disorders were highly prevalent (44%). Immobilization (26%) and prior trauma (11%) were other relevant antecedents. Among women, 22% were receiving oral contraceptive therapy. Premortem symptoms were reported in 52% of cases, mainly dyspnea (56%). Although 22 individuals sought medical attention, only one was correctly diagnosed. Toxicological analysis was performed in 67% of cases, with positive results for psychotropic drugs (20%) and substances of abuse/alcohol (9%).

PE is a common cause of SD in individuals younger than 50 years and is frequently clinically underdiagnosed. This study provides evidence supporting a strong association with obesity and psychiatric disorders, which facilitate immobilization, venous stasis, and a prothrombotic state. Forensic studies of SD due to PE offer complementary data to clinical research, revealing risk factors that are underrepresented in clinical cohorts.

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