Risk factors for the development of thoracic aortic aneurysm

Risk factors for the development of thoracic aortic aneurysm

Risk factors for the development of thoracic aortic aneurysm (TAA) are:

1. Hypertension is an important risk factor for atherosclerosis as well as thoracic aortic aneurysm
2. Smoking: Smoking is an important risk factor for development of thoracic aortic aneurysm. Longer duration of smoking and higher usage increases the risk.
3. Male gender
4. Advancing age: Risk of development of thoracic aortic aneurysm increases as the age advances. It is more common in those aged above sixty five years.
5. Obesity
6. Positive family history: genetic conditions like Marfan syndrome and Ehlers-Danlos syndrome predispose to aortic aneurysm. In these conditions, there is defect in the support to the aortic wall due to connective tissue involvement.
7. Bicuspid aortic valve

Accumulation of  atherosclerotic plaques damages and weakens the inner surface of the aorta and predisposes the aorta to aneurysm formation. Hence the risk factors for atherosclerosis also enhance the risk for aortic aneurysm formation [1].

An increase in mortality due to thoracic aortic aneurysm has been reported in countries like Hungary, Romania, Japan, and Denmark, while it has declined in several other countries [2]. A linear relationship has been noted in the trends of systolic blood pressure, cholesterol and body mass index and the mortality from thoracic aortic aneurysm. This reiterates the common risk factors between atherosclerosis and aortic aneurysm.

Risk factors for rupture of thoracic aortic aneurysms have also been studied. Rate of expansion more than 5.5 mm/year is a significant predictor of rupture. Other factors were aneurysm size more than 6.5 cm and dyslipidemia. Good control of dyslipidemia reduces the risk of rupture [3].

Reference

1. Harris C, Croce B, Cao C. Thoracic aortic aneurysm. Ann Cardiothorac Surg. 2016 Jul;5(4):407.
2. Sidloff D, Choke E, Stather P, Bown M, Thompson J, Sayers R. Mortality from thoracic aortic diseases and associations with cardiovascular risk factors. Circulation. 2014 Dec 23;130(25):2287-94.
3. Yiu RS, Cheng SW. Natural history and risk factors for rupture of thoracic aortic arch aneurysms. J Vasc Surg. 2016 May;63(5):1189-94.