Sudden deaths due to acute aortic wall failure: A 10-year forensic autopsy series.

Background: Acute aortic wall failure (AAWF), including rupture and/or dissection phenotypes, represents a rare but often fatal acute aortic event that may develop without overt aneurysmal dilatation. The underlying pathological substrate remains incompletely characterized, although standardized histopathological criteria proposed by the Society for Cardiovascular Pathology (SCVP) have recently improved the consistency of aortic wall assessment in forensic investigations. Methods: In this retrospective autopsy-based study, 5,277 adult autopsies performed between 2013 and 2023 were reviewed. Non-traumatic fatal AAWF, confirmed by macroscopic and histopathological examination, was included. A total of 93 cases were identified, of which 78 were evaluable histologically according to the SCVP criteria. Cases were classified as rupture without dissection, dissection with rupture, and dissection without rupture. The latter was included as a comparative subgroup to contextualize medial degeneration patterns within the spectrum. Demographic characteristics, comorbidities, event location, cardiac findings, and toxicological results were recorded. Results: AAWF accounted for 6.7% of cardiovascular deaths. Median age was 58 years (interquartile range 49-67), and 68.8% were male. Eighty cases demonstrated rupture (rupture without dissection or dissection with rupture). Younger decedents (19-45 years) had lower rates of documented hypertension and atherosclerosis, while a comparable proportion met ≥3 SCVP medial degeneration criteria. The ascending aorta was most frequently involved (62.4%). Among histologically examined cases, mucoid extracellular matrix accumulation (65.4%), elastic fiber fragmentation (60.3%), and smooth muscle cell depletion (55.1%) was the most prevalent SCVP features; 43.6% met ≥3 SCVP criteria. Documented hypertension was associated with more advanced medial degeneration on univariable analysis (p=0.002) and was interpreted as pathological coexistence rather than an independent causal determinant. Increased heart weight consistent with cardiac hypertrophy was observed in 80.5% of cases. Conclusion: Fatal AAWF is characterized by structural medial degeneration identifiable using SCVP criteria and frequently coexists with hypertensive cardiac remodeling in forensic autopsy findings. Standardized SCVP-based assessment may improve diagnostic consistency in forensic practice. Molecular autopsy, particularly in younger decedents, may further clarify etiopathogenesis and support targeted evaluation.