title: Left atrial volume and index by multi-detector computed tomography: comprehensive analysis from predictors of enlargement to predictive value for acute coronary syndrome (ROMICAT study).
abstract: OBJECTIVE
  We aimed to identify the predictors of left atrial (LA) enlargement by multi-detector computed tomography (CT) and determine its association and predictive value for acute coronary syndrome (ACS).
  
  
  BACKGROUND
  LA enlargement is associated with myocardial ischemia and coronary artery disease (CAD) and is a strong predictor for cardiovascular events. These studies were performed primarily with echocardiography. With the rise of cardiac CT, LA volume can be readily measured.
  
  
  METHODS
  In 377 emergency department patients with chest pain, we performed 64-slice CT for coronary artery assessment. We derived LA volumes (LAV(max), LAV(min)) and indices (LAVI(max), LAVI(min)) using a threshold-based volumetric method.
  
  
  RESULTS
  Subjects, with cardiac risk factors or CAD by CT, had larger LA (ΔLAV(max) 9.1 ml, p=0.004; ΔLAV(min) 8.1 ml, p=0.001; ΔLAVI(max) 3.3 ml/m(2), p=0.03; ΔLAVI(min) 3.4 ml/m(2), p=0.006) than controls. Predictors of LA enlargement were related to risk factors for diastolic dysfunction. ACS risk was greater in patients with top quartile LAV(max) (odds ratio [OR] 3.4, p=0.02) and LAV(min) (OR 4.7, p=0.01) than lowest quartile, but not when indexed. Similarly, the predictive values of LA volumes were incrementally better when added to CT finding of indeterminate stenosis (LAV(max): C statistic 0.62 to 0.70, p=0.046; LAV(min): C statistic 0.65 to 0.73, p=0.008), but not when indexed.
  
  
  CONCLUSIONS
  Risk factors related to diastolic dysfunction are independent predictors of LA enlargement. LA enlargement by volumes are associated with a 3-5 fold increase risk for ACS and have incremental value for predicting ACS when added to the CT finding of indeterminate stenosis.
authors.affiliation: Cardiac MR PET CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA. qtruong@partners.org
authors.forename: Quynh A
authors.initials: QA
authors.lastname: Truong
authors.forename: Fabian
authors.initials: F
authors.lastname: Bamberg
authors.forename: Amir A
authors.initials: AA
authors.lastname: Mahabadi
authors.forename: Michael
authors.initials: M
authors.lastname: Toepker
authors.forename: Hang
authors.initials: H
authors.lastname: Lee
authors.forename: Ian S
authors.initials: IS
authors.lastname: Rogers
authors.forename: Sujith K
authors.initials: SK
authors.lastname: Seneviratne
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Schlett
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Brady
authors.forename: John T
authors.initials: JT
authors.lastname: Nagurney
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging* / Q000453:epidemiology; D000328:Adult; D000368:Aged; D002306:Cardiac Volume; D006332:Cardiomegaly / Q000000981:diagnostic imaging* / Q000453:epidemiology; D015331:Cohort Studies; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*