Risk of Aortic Dissection in the Moderately Dilated Ascending Aorta.
Recent studies have demonstrated that many patients with acute type A aortic dissection (AD) have aortic diameters of <55 mm at presentation, prompting discussion of lowering the prophylactic surgical guidelines. However, risk of dissection at these smaller diameters is poorly defined.



The purpose of this study is to understand the risk of AD in moderately dilated ascending aortas using a large echocardiographic data set.



Using an institutional echocardiography database, we identified 4,654 nonsyndromic adults (age: 68.6 ± 13.1 years; 1,003 women) with maximal ascending aortic diameters of 40 to 55 mm. We performed competing risk analysis to determine the independent risk factors of AD or aortic rupture.



Five hundred eighty-six individuals (12.6%) had bicuspid aortic valves (BAVs). During follow-up (14,431.5 patient-years), AD and rupture occurred in 13 and 1 patients, respectively, which demonstrated a linearized incidence of AD and/or rupture of 0.1% per patient-year. Elective ascending aortic repair was performed in 176 individuals. On multivariable analyses, independent predictors of AD and/or rupture were age (hazard ratio [HR]: 1.06; 95% confidence interval [CI]: 1.01 to 1.12; p= 0.024) and baseline aortic diameters (HR: 1.20; 95% CI: 1.05 to 1.36; p = 0.006). The presence of a BAV was not a significant factor (HR: 0.94; 95% CI: 0.10 to 8.40; p = 0.95). Estimated risks of AD and/or rupture within 5 years were 0.4%, 1.1%, and 2.9% at baseline aortic diameters of 45, 50, and 55 mm, respectively.



Risks of AD and/or rupture were significantly correlated with the aortic diameter and age in patients with moderately dilated ascending aortas. However, the risks were low for diameters <5.0 cm when timely elective aortic repair was performed, regardless of the morphology of the aortic valve.
Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Joon Bum
JB
Kim
Division of Cardiac Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Harvard T.H. Chan School of Public Health, Cambridge, Massachusetts.
Matthew
M
Spotnitz
Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Pediatric Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Thoracic Aortic Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
Mark E
ME
Lindsay
Division of Cardiac Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Thoracic Aortic Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
Thomas E
TE
MacGillivray
Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Thoracic Aortic Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
Eric M
EM
Isselbacher
Division of Cardiac Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Thoracic Aortic Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address: tsundt@partners.org.
Thoralf M
TM
Sundt
D000368:Aged; D000784:Aortic Dissection / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology*; D001011:Aorta / Q000000981:diagnostic imaging / Q000473:pathology*; D017545:Aortic Aneurysm, Thoracic / Q000150:complications* / Q000000981:diagnostic imaging; D001021:Aortic Valve / Q000002:abnormalities; D000082882:Bicuspid Aortic Valve Disease; D004108:Dilatation, Pathologic / Q000150:complications / Q000000981:diagnostic imaging; D004452:Echocardiography; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index
aneurysm; aorta; aortic dissection; prognosis; risk factors