Abstract 15770: Sex Differences in Growth Rates of Thoracic Aortic Aneurysms
Introduction: Thoracic aortic aneurysm (TAA) is a deadly disease of increasing prevalence. Although more prevalent in men, TAA-related mortality is higher in women. In addition, women develop acute aortic syndromes at smaller aneurysm diameters, independently of body size. However, the basis for worse TAA outcomes in women is unknown. Since faster TAA growth is an established risk factor for acute aortic syndromes, we sought to determine the role of sex on TAA growth.
Hypothesis: We hypothesized that TAA growth rates differ based on sex.
Methods: Fifty three consecutive unoperated subjects with TAA who had serial aneurysm measurements by CT, MRI or echocardiography were prospectively recruited. Aneurysm size was measured systematically by an imaging cardiologist (TC); growth rate was calculated as mm/year. In multivariable linear regression, the association of female sex with aneurysm growth rate was assessed after adjustment for age, and then additional adjustment for body surface area, baseline aneurysm size, beta-blocker use and history of hypertension, diabetes, dyslipidemia and smoking.
Results: Thirty seven (70%) subjects were men; mean±SD age was 63.7±11.9 years (62.2±12.3 in men, 66.9±10.6 in women, P=0.17). Thirty (57%) subjects had degenerative TAAs, the remainder had heritable TAAs. Fifteen had maximal dilation at the aortic root, and 38 at the ascending aorta. Baseline aneurysm size and follow-up time were 45.4±4.5 mm and 3.01±2.9 years, respectively, and not different between men and women (P>0.05 for both). Aneurysm growth rate was 1.22±1.09 mm/year in women and 0.68±0.68 mm/year in men. Female sex was significantly associated with greater aneurysm growth rate after adjustment for age (β±SE: 0.25±0.13, P=0.05) and additional adjustment for confounders (β±SE: 0.30±0.14, P=0.03). Notably, baseline aneurysm size was not associated with TAA growth (β±SE: -0.01±0.0.03, P=0.72).
Conclusions: In subjects with TAA from different etiologies, reflecting clinical practice, aneurysm growth rates are greater in women than men. Our findings may potentially explain sex differences in TAA outcomes, providing a foundation for future investigations aimed at assessing causes for faster aneurysm growth and acute aortic syndromes in women.
Author Disclosures: K. Cheung: None. M. Boodhwani: None. K. Chan: None. L. Beauchesne: None. A. Dick: None. T. Coutinho: None.
- © 2015 by American Heart Association, Inc.