NEW YORK – Aortic aneurysm ranks as one of the top 20 causes of death in the United States. Most of these aneurysms are clinically silent until they rupture, but Yale cardiovascular surgeon John A. Elefteriades, MD, has developed a clinical paradigm that identifies eight markers that physicians can use to detect the disease before it strikes.
Dr. Elefteriades calls his paradigm “Guilt by Association.” It is based on an article he published online last year in the journal Open Heart (2015;2:e000169).
Dr. John A. Elefteriades
“What we need is for our colleagues in affiliated disciplines to recognize the importance of these offenders in indicating the presence of thoracic aortic aneurysm,” he said, reporting on the paradigm at the meeting sponsored by the American Association for Thoracic Surgery. He noted that studies from Japan of people who had died from out-of-hospital cardiac arrest found that 8% of them had a type A aortic dissection (Am J Cardiol 2016;117:1826-30).
He outlined eight “associates” of thoracic aortic aneurysm (TAA): intracranial aneurysm; bovine aortic arch; abdominal aortic aneurysm; simple renal cysts; bicuspid aortic valve; family history; positive thumb-palm test; and temporal arteritis and other autoimmune disorders.
A patient with TAA has a 10% likelihood of harboring an intracranial aneurysm (Am J Cardiol 2010;105:417-20). “It’s even more common in the descending, compared to the ascending group in examples that we’ve identified,” Dr. Elefteriades said. Particularly vulnerable are patients over age 70 and those with an intracranial aneurysm larger than 4 mm: the former has a 9% chance of harboring a TAA, the latter a 6% chance, he said.
The bovine arch had been thought to be benign, but, Dr. Elefteriades said, “We don’t think it is.”
Bovine arch refers to a group of congenital aortic arch vessels with an aberrant origin of the left common carotid artery. “We recently looked at this as a marker for thoracic aortic disease, and please note that 20% of our TAA patients have a bovine arch,” he said. “This is much higher than in the general population.”
Abdominal aortic aneurysm has long been associated with TAA, he said. “When these aneurysms are identified by ultrasound, it’s important that the thoracic aorta be checked as well,” he said.
“This is a message for internists and our vascular colleagues.”
Simple renal cysts have been found in patients with TAA at a “much higher” rate than the general population, as high as 57% of those with descending aortic aneurysms vs. 11%-13.7% of the general population, Dr. Elefteriades said (J. Am. Heart Assoc. 2016;5:e002248). Simple renal cysts are detected by abdominal CT scan. “It’s just a matter of a few more slices with the CT scan to get the entirety of the thoracic aorta evaluated,” he said.
Courtesy Dr. Elefteriades
The thumb-palm sign: Note the extension of the thumb beyond the border of the flat palm. This indicates connective tissue disease and should prompt an aneurysm investigation.
“We encourage our radiology colleagues to do this when a renal cyst is detected.”
Bicuspid aortic valve mandates “support from our cardiac colleagues when they find one of these to let the patient know he has to be monitored lifelong for later development of this aneurysm,” Dr. Elefteriades said.
Family history of TAA has been known as a strong predictor, but genetic studies have provided clarity on the association (Arch Surg. 1999;134:361‐7). “If the proband has a thoracic aortic aneurysm, there’s 21% likelihood there’s a family member who is affected with an aneurysm somewhere in the body,” he said.
Location of aneurysms in family members is also important, Dr. Elefteriades said. “If the proband has a ascending aortic aneurysm, the kindred also have an ascending aortic aneurysm; but if the proband has a descending aneurysm, the likelihood is that the kindred will have an abdominal aortic aneurysm,” he said. “To identify silent disease, it’s very important we check siblings and children, and now, of course, we’re using whole-exome sequencing.” So far, Dr. Elefteriades has obtained whole-exome sequencing in 200 patients.
The thumb-palm test involves the patient touching the thumb to the palm; the thumb crossing the edge of the flat palm is an indicator of connective tissue disease. “It doesn’t cost anything,” Dr. Elefteriades said. “It is a very simple thing for internists to do to identify those connective tissue diseases.”
Temporal arteritis has become increasingly common in elderly women. “They have a markedly increased likelihood of having a thoracic aortic aneurysm – about 8% in some studies,’ Dr. Elefteriades said. “So we want our neurology colleagues to be aware of this and to look for thoracic aortic aneurysm.”