Autopsy-confirmed sudden cardiac death in a Brazilian metropolitan region (2019–2022): a retrospective observational study

Abstract Background Sudden cardiac death is defined as an unexpected natural death of presumed cardiac origin that occurs within a short interval, usually within 1 h of symptom onset, in individuals with or without previously known heart disease. Epidemiological data based on autopsy-confirmed cases of sudden cardiac death in Brazil remain limited. Objective We aimed to describe the epidemiological characteristics, autopsy-based pathological causes, and sex-stratified and age group-stratified differences among sudden cardiac death cases in a Brazilian metropolitan region between 2019 and 2022. Methods This retrospective descriptive study analyzed data extracted from death certificates, medical records, and autopsy reports within the Death Verification Service (Serviço de Verificação de Óbitos) in Goiânia and its metropolitan region. Sudden deaths were identified according to World Health Organization criteria. Cases that were clinically suspected of cardiac origin were evaluated, and details of the postmortem examination were used to confirm or reclassify the cause of death. Categorical variables were reported using both absolute and relative frequencies, with 95% confidence intervals. Exploratory analyses, stratified by sex and age group, were conducted using the chi-square test. Results During the study period, 2,878 sudden deaths were registered; of these, 1,920 (67.3%; 95% confidence interval: 65.6–69.0) were clinically suspected to have a cardiac etiology, but only 322 autopsies (16.8%; 95% confidence interval: 15.2–18.5), which comprise a minor fraction of the suspected cases, were undertaken, and this underscores the constraints in postmortem examination. Sudden cardiac death was validated in 303 cases (94.1%; 95% confidence interval: 90.9–96.4). The most common pathological finding in autopsies was ischemic heart disease ( n = 121), followed by Chagas disease ( n = 76), rheumatic cardiomyopathy ( n = 61), and myocarditis ( n = 30). Infective endocarditis ( n = 3), hypertrophic cardiomyopathy ( n = 1), cardiac sarcoidosis ( n = 1), and other or unspecified cardiac causes ( n = 10) were less common. The distribution of these causes, as determined by autopsy, differed by sex (χ 2 (4) = 15.41, p = 0.0039) and age group (χ 2 (8) = 73.73, p < 0.001). Postmortem examinations confirmed the cause of sudden cardiac death in most clinically suspected cases and revealed various causes that differed by sex and age group. These findings underscore the importance of autopsies for determining the cause of death and monitoring mortality trends. Conclusion Autopsy-confirmed sudden cardiac death in this Brazilian metropolitan cohort was predominantly caused by ischemic heart disease, but non-ischemic causes—particularly Chagas cardiomyopathy and rheumatic heart disease—also contributed substantially. These findings highlight the continued epidemiological importance of endemic and socioeconomic cardiovascular conditions and reinforce the value of systematic autopsy investigations for accurate mortality surveillance.