Redefining the Post-Mortem Investigation of Sudden Cardiac Death: Systematic Cardiac MR with Macroscopic and Histological Correlation from the Friuli Venezia Giulia Regional Registry

Objectives: Sudden cardiac death (SCD) is a leading cause of mortality, accounting for approximately 50% of all cardiovascular deaths and 20% of all-natural deaths in Western countries. In individuals over 50 years of age, coronary artery disease (CAD) is responsible for more than 80% of cases, whereas in younger subjects SCD is more frequently associated with non-ischemic myocardial diseases, including hypertrophic cardiomyopathy (HCM), arrhythmogenic cardiomyopathy (ACM), dilated cardiomyopathy (DCM), and myocarditis. Additional causes in young adults include coronary artery anomalies and primary arrhythmic disorders related to channelopathies. This study evaluated the diagnostic performance of post-mortem cardiac magnetic resonance imaging (PM-CMR) in identifying morphological substrates underlying SCD in formalin-fixed explanted hearts, with particular attention to the concordance between PM-CMR findings and autopsy results in cases of sudden coronary death. Material and Methods: We retrospectively reviewed 110 PM-CMR examinations from the Regional Register of Sudden Cardiac Death of Friuli-Venezia Giulia, of which 101 were included in the final analysis. Results: PM-CMR detected pathological findings in 60 hearts (59%), including acute ischemic lesions in 39 cases and other conditions, such as hypertrophic cardiomyopathy, chronic fibrotic ischemic changes, and adipose metaplasia in 21 cases. A good agreement between PM-CMR and autopsy findings was observed (Cohen’s kappa = 0.8). Conclusions: Overall, PM-CMR proved effective in identifying relevant morphological and signal alterations, supporting conventional autopsy. Despite some limitations, particularly in hyperacute ischemic lesions, PM-CMR appears to play a promising role in the diagnostic work-up of SCD and in supporting family screening programs for primary prevention.