Gender-specific differences in aortic sinus curvature during aging: an anatomical and computational study

IntroductionOur goal was to investigate the potential impact of aortic sinus wall curvature on the risk for type A aortic dissection.MethodsWe measured the curvature and carried out histological tests of the aortic noncoronary sinus in 46 patients who did not die from cardiac disease. Based on observed curvature values, we investigated the mechanical stress in the aortic root using finite element analysis.ResultsSinus curvature was found to experience a more than fourfold increase with age in males and reached the higher, age-independent values measured in females by age 65. The histological tests revealed that degenerative alterations did not significantly increase with aging in either gender, although fibrosis did in older women. Finite element analysis illustrated that the risk for a circumferential tear to occur was smallest when sinus curvature was highest.ConclusionsWe established significant gender-specific disparities in the aortic root during aging: while aortic sinus curvature was high in females throughout their lives, it experienced a more than fourfold increase in the lifetime of males, matching values in females only by age 65. Our mechanical analyses confirmed the overall potential protective role of higher sinus wall curvature with respect to type A aortic dissection, and geometry alone could not account for the known gender difference in aortic dissection prevalence.