From the Guidelines
Thoracic aortic aneurysms are primarily caused by degenerative disease, with risk factors including hypertension, smoking, and chronic obstructive pulmonary disease, as well as genetic syndromes and congenital cardiovascular anomalies. The causes of thoracic aortic aneurysms can be multifactorial, involving a combination of genetic, environmental, and lifestyle factors. According to the most recent study 1, genetic diseases affecting the aorta, such as Marfan syndrome, Loeys-Dietz syndrome, and vascular Ehlers-Danlos syndrome, play a significant role in the development of thoracic aortic aneurysms.
Key Causes and Risk Factors
- Degenerative disease, including atherosclerosis and medial degeneration with fragmentation of elastic fibers 1
- Genetic disorders, such as Marfan syndrome, Loeys-Dietz syndrome, and Ehlers-Danlos syndrome 1
- Congenital heart defects, including bicuspid aortic valve 1
- Hypertension, which creates excessive pressure on the aortic walls 1
- Inflammatory conditions, such as giant cell arteritis and Takayasu arteritis
- Infections, such as syphilis or fungal infections (mycotic aneurysms)
- Trauma from accidents or injuries
- Age-related degeneration of the aortic tissue
- Lifestyle factors, including smoking and cocaine use
Importance of Identification and Prevention
Understanding the causes of thoracic aortic aneurysms is crucial for identifying high-risk individuals who may benefit from screening and preventive measures, such as blood pressure control, smoking cessation, and genetic counseling 1. A thorough family history, directed physical examination, multimodality imaging, and often genetic testing are essential steps in the diagnosis and management of a dilated ascending aorta 1.
From the Research
Causes of Thoracic Aortic Aneurysm
- Most thoracic aortic aneurysms are degenerative 2
- Some are associated with connective tissue disorders, bicuspid aortic valves, or familial/genetic predisposition 2, 3
- Connective tissue disorders such as Marfan syndrome and Ehlers-Danlos syndrome can increase the risk of thoracic aortic aneurysm 3, 4, 5
- Bicuspid aortic valve is also a risk factor for thoracic aortic aneurysm 2, 3
- Genetic predisposition can play a role in the development of thoracic aortic aneurysm, with some cases being caused by pathogenetic variants in the FBN1 gene 5
Risk Factors
- Atherosclerosis is a risk factor for the development of thoracic aortic aneurysms and thoracoabdominal aneurysms 3
- Hypertension and smoking can accelerate the growth of thoracic aortic aneurysms 2
- Size of the aneurysm is a predictor of the risk of complications, with larger aneurysms being more likely to rupture or dissect 2, 3
Genetic Syndromes
- Marfan syndrome is an autosomal dominant condition that can cause thoracic aortic aneurysms, with up to 25% of cases being caused by de novo variants in the FBN1 gene 5
- Ehlers-Danlos syndrome is another connective tissue disorder that can increase the risk of thoracic aortic aneurysm 4, 6
- Loeys-Dietz syndrome is also a genetic syndrome that can increase the risk of thoracic aortic aneurysm 3