Women represented 46.2% of the type A group and 26.0% of the type B group. Aortic intramural hematoma is bleeding within the wall of the aorta. In this study, type A disease involved the ascending aorta, the segment closest to the heart, whereas type B disease involved the descending aorta farther from the heart.

The investigators separated the two anatomical subtypes because their management and prognosis differ: type A disease is generally more life-threatening and often requires emergency surgery, while type B disease is usually managed with medication. The study examined whether the association between sex and clinical outcomes differed according to hematoma subtype. The primary outcome was all-cause death during follow-up.

Secondary outcomes included death during the initial hospital admission, aortic-related death during follow-up, and major adverse events. Multivariable Cox regression was used to assess the association between sex and outcomes after adjustment for measured factors such as age, other illnesses and hematoma severity. The researchers also conducted sensitivity analyses that included propensity score analysis, along with subgroup analyses intended to test the consistency of the main findings.

These methods were intended to reduce measured confounding, although an observational cohort cannot establish that sex itself caused the observed differences. Among patients with type A intramural hematoma, women had significantly higher incidence of the reported mortality outcomes. In-hospital death occurred in 8.3% of women and 3.9% of men, and the difference remained apparent over longer-term follow-up.

After multivariable adjustment, female sex was independently associated with increased in-hospital death, with a hazard ratio of 2.38 and a 95% confidence interval of 1.16 to 4.90; the reported p value was 0.019. Female sex was also associated with all-cause death during follow-up, with a hazard ratio of 1.87 and a 95% confidence interval of 1.23 to 2.83, and with aortic-related death, with a hazard ratio of 2.01 and a 95% confidence interval of 1.18 to 3.43. The respective p values for those adjusted associations were 0.003 and 0.010.

Sensitivity and subgroup analyses were generally consistent with the main results, although the sex-related differences in in-hospital and aortic-related mortality for type A disease did not reach statistical significance in the propensity score analysis. The subtype-specific pattern was not observed in type B intramural hematoma. There were no statistically significant differences between women and men for in-hospital death, all-cause death during follow-up, aortic-related death or major adverse events; all reported p values were greater than 0.05.

Taken together, the results support an association between female sex and poorer mortality outcomes specifically in type A disease within the studied population, rather than a uniform disparity across both subtypes. As a single-center observational study, the research was limited in its ability to separate sex from other differences between patient groups or to determine whether the same associations occur in other healthcare settings.

Subject of Research: Sex-specific mortality outcomes in type A and type B aortic intramural hematoma

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

Article References: Lyu, S.-Q., Yang, Y.-M., Wang, J., Xin, Y.-J., Zheng, L.-H., & Wu, S. (2026). Sex-specific disparities in clinical outcomes of type A and type B aortic intramural hematoma: a cohort study. Biology of Sex Differences. https://doi.org/10.1186/s13293-026-01002-8

Image Credits: AI Generated

DOI: 10.1186/s13293-026-01002-8

Keywords: aortic intramural hematoma, type A hematoma, type B hematoma, sex differences, mortality, aortic disease, cohort study, risk stratification, Sex-specific, disparities, clinical, outcomes