Sex Differences in Thoracic Aortic Aneurysm Growth, Role of Aortic Stiffness

Sex Differences in Thoracic Aortic Aneurysm Growth, Role of Aortic Stiffness

Hypertension. 2019;73:190-196. DOI: 10.1161/HYPERTENSIONAHA.118.11851

Thoracic aortic aneurysms are associated with a high mortality and morbidity. Somme differences have been reported according to patients sex. The prevalence of thoracic aortic aneurysms  is higher in men, but the prognosis is poorer in women. In women a 40% increase in the risk of mortality was observed , when compared with men. Women have also  a 3-fold increase in the risk of thoracic aortic aneurysms dissection or rupture.

Previously published data have  shown that  the rate of growth of thoracic aorta aneurysm is faster in women , possibly explaining the sex differences in thoracic aorta aneurysms  outcomes. Boczar et al have evaluated the role of  pulsatile hemaodynamics and aortic stiffness on thoracic aorta aneurysms growth in more than 100 unoperated patients, including 26 % of women , with mostly degenerative aortopathy.

Thoracic aortic aneurysms growth was calculated from the measures of oldest and latest maximal aneurysm size at imaging studies. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV) using applanation tonometry.

The  association of cfPWV with thoracic aortic aneurysms growth was assessed by multivariable linear regression,adjusted for confounders.

No significant differences were observed for age, baseline aneurysm size, follow-up time, and cfPWV between men and women.  TAA growth rate was almost twice faster in women than in men ( 0.96±1.00 mm/y in women and 0.45±0.58 mm/y in men , respectively, (P=0.006).

In the whole group, cfPWV was independently associated with thoracic aortic aneurysms growth (β±SE: 0.06±0.02, P=0.02). However, in sex-specific analyses cfPWV was independently associated with faster aneurysm growth in women (β±SE: 0.21±0.09, P=0.03), but not in men (β±SE: −0.002±0.02, P=0.94), with a significant sex×cfPWV interaction (P<0.0001). 

Despite the study cannot explain  whether a stiffer aneurysm  is more  likely to expand faster or if a fast-growing aneurysm  is  more likely to become stiffer , the findings confirm the association between aortic stiffness and aneurysm  growth velocity .

Authors have analyzed  non only the correlation between aortic stiffness and aneurysm growth , but also  the role of  abnormal central hemodynamics. In this cohort  women had  higher central pulse pressure values and greater augmentation  index than men , although differences did not reach statistical significance. Accelerated aneurysm growth was related to central pulse pressure both in men and women, while augmentation index was not. 

The results of this study further highlight a potential role for sex differences in arterial aging on cardiovascular disease and outcomes.