Aortic size distribution among normal, hypertension, bicuspid, and Marfan populations.

Aims: Large-scale investigations on ascending aortic diameter, especially in the Asian population, are lacking. Furthermore, relevant evidence regarding the distribution of hypertension (HP), bicuspid aortic valve (BAV), and Marfan syndrome (MFS) is scarce. We aimed to examine the distribution of ascending aortic diameter in these populations in China.

Methods and results: The data of a total number of 698 795 individuals who underwent cardiac ultrasound were subjected to retrospective analysis. After screening, 647 087 individuals were included in the final analysis. In the normal population, the mean ascending aortic diameter was 28.1 ± 3.2 mm (27.2 ± 3.1 mm in women vs. 29.0 ± 3.1 mm in men) (P < 0.001). Aortic diameter increased gradually with age (P < 0.001). The prevalence of aortic dilation, aneurysm, and dissection in individuals with HP was 12.83%, 2.70%, and 4.77%, respectively. In individuals with MFS, the corresponding rates were 43.92%, 35.31%, and 26.11%. Notably, although BAV patients had high incidences of aortic dilation (37.00%) and aortic aneurysm (16.46%), the incidence of aortic dissection was relatively low (0.74%). Most cases of aortic dissection occurred at an aortic diameter of less than 55 mm. However, in the overall population, the incidence of aortic dissection significantly increased with the increase in the aortic diameter, revealing the existence of an 'aortic paradox'.

Conclusions: (i) The ascending diameter increases with age and is larger in men than in women; (ii) 'Aortic paradox' is explained; (iii) BAV bears a high rate of aortic dilation, but a low incidence of aortic dissection.