title: Novel measurement of relative aortic size predicts rupture of thoracic aortic aneurysms.
abstract: BACKGROUND
  Optimal operative decision making in thoracic aortic aneurysms requires accurate information on the risk of complications during expectant management. Cumulative and yearly risks of rupture, dissection, and death before operative repair increase with increasing aortic size, but previous work has not addressed the impact of relative aortic size on complication rates.
  
  
  METHODS
  Our institutional database contains data on 805 patients followed up serially with thoracic aortic aneurysms. Body surface area information was obtained on 410 patients (257 male, 153 female). We calculated a new measure of relative aortic size, the "aortic size index," and examined its ability to predict complications in these patients.
  
  
  RESULTS
  Increasing aortic size index was a significant predictor of increasing rates of rupture (p = 0.0014) as well as the combined endpoint of rupture, death, or dissection (p < 0.0001). Using aortic size index, patients were stratified into three risk groups: less than 2.75 cm/m2 are at low risk (approximately 4% per year), 2.75 to 4.24 cm/m2 are at moderate risk (approximately 8% per year), and those above 4.25 cm/m2 are at high risk (approximately 20% per year).
  
  
  CONCLUSIONS
  This study confirms that (1) thoracic aortic aneurysm is a lethal disease, (2) relative aortic size is more important than absolute aortic size in predicting complications, and (3) a novel measurement of relative aortic size allows for the stratification of patients into three levels of risk, enabling appropriate surgical decision-making.
authors.affiliation: Section of Cardiothoracic Surgery, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Davies
authors.forename: Amy
authors.initials: A
authors.lastname: Gallo
authors.forename: Michael A
authors.initials: MA
authors.lastname: Coady
authors.forename: George
authors.initials: G
authors.lastname: Tellides
authors.forename: Donald M
authors.initials: DM
authors.lastname: Botta
authors.forename: Brendan
authors.initials: B
authors.lastname: Burke
authors.forename: Marcus P
authors.initials: MP
authors.lastname: Coe
authors.forename: Gary S
authors.initials: GS
authors.lastname: Kopf
authors.forename: John A
authors.initials: JA
authors.lastname: Elefteriades
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000209:etiology / Q000401:mortality / Q000473:pathology / Q000601:surgery; D000886:Anthropometry / Q000379:methods*; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000473:pathology*; D017545:Aortic Aneurysm, Thoracic / Q000150:complications / Q000235:genetics / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D001019:Aortic Rupture / Q000453:epidemiology* / Q000401:mortality / Q000601:surgery; D001830:Body Surface Area; D002648:Child; D016208:Databases, Factual; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D015993:Life Tables; D008297:Male; D008382:Marfan Syndrome / Q000150:complications; D008875:Middle Aged; D009929:Organ Size; D011859:Radiography; D012306:Risk; D012422:Rupture, Spontaneous; D016019:Survival Analysis; D014463:Ultrasonography