Sex-specific disparities in clinical outcomes of type A and type B aortic intramural hematoma: a cohort study

Background Sex-specific disparities in aortic intramural hematoma (IMH) remain inadequately characterized. This study aimed to investigate the impact of sex on clinical outcomes of type A and type B IMH. Methods A total of 1,590 patients with IMH presenting to emergency department (626 with type A IMH, 964 with type B IMH) were enrolled. The primary outcome was all-cause death during follow-up, while the secondary outcomes included in-hospital death, aortic-related death, and major adverse events during follow-up. Multivariable Cox regression was employed to evaluate the association between sex and outcomes stratified by IMH subtype. Sensitivity analysis (including propensity score analysis) and subgroup analysis were undertaken to test the consistency of the results. Results Female patients comprised 46.2% of the type A IMH cohort and 26.0% of the type B IMH cohort. In patients with type A IMH, females had significantly higher incidences of primary and secondary endpoints. After multivariable adjustment, female sex remained independently associated with increased risks of in-hospital death [HR (95%CI): 2.38 (1.16–4.90), p = 0.019], all-cause death [HR (95%CI): 1.87 (1.23–2.83), p = 0.003] and aortic-related death during follow-up [HR (95%CI): 2.01 (1.18–3.43), p = 0.010]. In contrast, no significant sex-related differences were observed in the type B IMH cohort across any endpoint (all p > 0.05). Sensitivity analysis and subgroup analysis showed generally consistent results, although the sex-related disparities in in-hospital mortality and aortic-related mortality of type A IMH did not reach statistical significance in the propensity score analysis. Conclusions Female sex is independently associated with worse short-term and long-term mortality in type A IMH, whereas no such disparity exists in type B IMH. These findings underscore the subtype-specific prognostic impact of sex and highlight the need for sex-aware risk stratification and management strategies. Further prospective studies are required to clarify this correlation.