We report a case of non‐syndromic familial thoracic aortic aneurysm and aortic dissection (FTAAD) discovered in a 31‐year‐old man presenting with heart failure secondary to a 9.5cm ascending aortic aneurysm. He underwent urgent aortic root and valve replacement. Surgery was successful and he has been recovering very well with physical therapy and cardiac rehabilitation. Histopathology revealed cystic medial degeneration in the absence of a phenotypic syndrome (i.e. Marfan’s, Ehlers‐Danlos, Loeys‐Dietz). Further exploration of family history revealed that the patient’s mother has an ascending aortic aneurysm and maternal aunt died from a spontaneously ruptured aortic aneurysm. He denied any family history of connective tissue syndromes. Given his family history suggestive of FTAAD, he was offered genetic testing to guide appropriate surveillance of his other vasculature and genetic screening of potentially affected family members.
Aortic aneurysms are the 13th leading cause of death in the United States and go undetected until rupture with mortality as high as 90%. TAAD are associated with cystic medial degeneration, with fragmentation of elastic fibers, loss of smooth muscle cells, and a collection of basophilic ground substance. Although this condition often occurs sporadically, about 20% is genetically inherited, including syndromic and and non‐syndromic FTAAD. Syndromic FTAAD is a manifestation of genetic diseases (i.e. MFS, LDS, EDS, and Turner syndrome) that affect many organ systems, mostly single gene mutations with autosomal dominant (AD) inheritance model, and associated with classic phenotypic features. Conversely, non‐syndromic FTAAD is diagnosed by the presence of aortic aneurysm and/or dissection and positive family history for TAAD in the absence of syndromic clinical features. There are currently seven genes identified with non‐syndromic FTAAD, which only accounts for 20% of reported cases, and are of an AD inheritance model with variable expression and decreased penetrance.
Identification of gene mutations has significant clinical implication because each confers different risks and parameters for surveillance given multi‐organ effects in syndromic patients and associations with strokes, coronary artery disease, and early dissections with minimal dilatations in non‐syndromic patients. Management of both syndromic and non‐syndromic FTAAD is similar, requiring a team of geneticist, cardiologist, and cardiothoracic surgeon. Secondary prevention strategies employed for syndromic patients should be applied to all patients with FTAAD. Hypertension should be aggressively controlled. Dyslipidemia, isometric exercise and smoking cessation should be addressed. Additionally, aortic prophylactic surgical repair at smaller diameter of dilatation and lifelong surveillance imaging of cerebral circulation, coronary arteries, and aortic arterial branches may be indicated. This is also applied to family members that are genetically screened and found to be heterozygous for mutation.
This case demonstrates that familial aortic aneurysms and dissections can occur outside of known connective tissue syndromes. Thus we emphasize the importance of getting detailed family history and genetic testing in persons with TAAD in order to guide decisions for lifelong surveillance of potentially affected vasculature for both the patient and first degree relatives.
To cite this abstract:Vo P, Ramachandran K, Jao G, Savage R. Genetically‐Linked Large Ascending Thoracic Aortic Aneurysm with Dissection in a Young Male Without Syndromic Connective Tissue Disease. Abstract published at Hospital Medicine 2014, March 24-27, Las Vegas, Nev. Abstract 667. Journal of Hospital Medicine. 2014; 9 (suppl 2). https://www.shmabstracts.com/abstract/geneticallylinked-large-ascending-thoracic-aortic-aneurysm-with-dissection-in-a-young-male-without-syndromic-connective-tissue-disease/. Accessed March 20, 2019.