Background: A prior small case control study had suggested that Ascending Aortic Aneurysm (AAA) is an inherited disease followed by multiple small studies on the genetic basis of the disease. A recent large observational study evaluated diabetes to have a protective role against AAA. However, there is a lack of studies that evaluate multiple risk factors in the same study population.

Methods: The echocardiography database of a large tertiary care center was electronically evaluated, over 4 years, in adults >15 years of age. AAA was defined as a sinus of Valsalva dilation, based on age, sex and BSA indexed definition recommended by American Society of Echocardiography. The presence of 24 risk factors of AAA were assessed in the electronic medical record.

Results: Of 37,914 patients, there were 1,035 cases of AAA, with 662 (64%) men. The study population comprised of hereditary risk factors including Marfan Syndrome (26; 0.06%), coarctation of aorta (CoA; 17; 0.05%), bicuspid aortic valve (BAV; 192; 0.5%), polycystic kidney disease (PCKD; 64; 0.17%) and hypertrophic cardiomyopathy (HCM; 249; 0.66%), as well as acquired risk factors including cocaine use (219; 0.58%), smoking (20,674; 55.6%), dyslipidemia (21,273; 56.1%), diabetes mellitus (9,774; 25.8%), aortic valve disease (3,507; 9.3%) and hypertension (24,156; 63.7%). The risk factors of developing AAA in descending order of strength of odds ratio were Marfan syndrome (6.5), CoA (4.8), BAV(4.2), cocaine use (2.5), PCKD (2.4), HCM (2.4), male gender (2.2) and aortic valve disease (2.0). The risk factors of atherosclerotic disease which include age > 65, diabetes mellitus and dyslipidemia were found to have a negative association, whereas smoking and hypertension had null effect. These associations persisted in multivariate logistic regression models.

Conclusions: Out of top 10 risk factors of AAA, only three 3 are not purely inherited. The traditional atherosclerotic risk factors either have null effect on AAA, or have a paradoxical relationship. These data further support the hypothesis that AAA might indeed be a hereditary disease.