Sex differences in ascending aortic diameter at the time of acute type A aortic dissection

Guideline size criteria for prophylactic repair of ascending aortic aneurysm do not account for sex, although some evidence suggests women may experience acute type A aortic dissection (ATAAD) at smaller diameters. We examined sex differences in ascending aortic diameter among patients with ATAAD.

We performed a single-centre, retrospective study including consecutive adult patients undergoing repair of spontaneous ATAAD (2011-2023). Maximal ascending aortic diameter was measured on index CT. Maximum diameter and diameter indexed to height and body surface area (BSA) were compared by sex. Multivariable linear regression, accounting for sex, age and comorbidities, predicted aortic diameter at time of ATAAD. Height and BSA were separately added to the model to evaluate how associations changed with body size.

Among 413 included patients, 146 (35.4%) were female. Women were older (65 years vs 58 years, p<0.001) and had a smaller height and BSA than men. Women had smaller aortic diameter at the time of dissection (46.6 mm vs 48.5 mm, p=0.035), but a larger aorta indexed to height (28.7 mm/m vs 27.2 mm/m, p=0.001) and BSA (25.7 mm/m² vs 22.97 mm/m², p<0.001). Female sex was associated with smaller diameter after adjusting for comorbidities (β=-1.77 (95% CI -3.12 to -0.42), p=0.010). This association disappeared after adjusting for height and BSA.

Female sex was associated with ATAAD at a smaller absolute diameter, an association that resolved when accounting for women's smaller body size . Sex-specific guidelines for ascending aneurysm repair or guidelines accounting for body size may reduce preventable complications among women.