National sudden cardiac death autopsy database highlighting sudden arrhythmic death and cardiomyopathies, applying diagnostic criteria and expanding the concept of the molecular autopsy

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Other. Main funding source(s): Cardiac Risk in the Young BACKGROUND: Sudden cardiac death (SCD) is defined as natural unexpected death in witnessed cases occurring <1 hour and in unwitnessed cases as last seen alive <24hours. SCD due to ischaemic heart disease (IHD) is frequent in older age groups, in younger people genetic cardiac causes including channelopathies and cardiomyopathies are more frequent. PURPOSE: To present the causes of SCD from a large pathology registry. METHODS: Cases were examined macroscopically and microscopically by two expert cardiac pathologists. Criteria used are presented in figure 1. RESULTS: The hearts from 7214 SCD cases were examined between 1994-2021. Sudden arrhythmic death syndrome (SADS), a morphologically normal heart, which can be underlain by the channelopathies, is most common (3821, 53%) followed by the cardiomyopathies (1558, 22%), then IHD (670, 9%). Valve disease (225, 3%), congenital heart disease (213, 3%) and myocarditis/sarcoidosis (206, 3%) are the next most common. Hypertensive heart disease (185, 3%), aortic disease (129, 2%), vascular disease (97, 1%) and conduction disease (40, 1%) are smaller proportions (figure 2). DISCUSSION: This is the largest SCD cohort with autopsy findings ever reported from one country. SADS and cardiomyopathies predominate. This study highlights the importance of the autopsy in SCD which is a significant public health concern in all age groups. Knowing the true incidence in our population will improve risk stratification and develop preventative strategies for family members. There is now a national pilot study integrating molecular autopsy into the assessment of SCD victims. [Figure: see text] [Figure: see text]