title: Lack of association between stroke and left atrial out-pouching structures: results of a case-control study.
abstract: OBJECTIVE
  Clinical significance of out-pouching structures of the left atrium (LA) as potential embolic sources remains unclear. We sought to evaluate the association between stroke and LA out-pouching structures.
  
  
  METHODS
  A case-control study was conducted to assess the prevalence of LA out-pouching structures in subjects with and without stroke. Case subjects were 270 stroke patients who had undergone cardiac CT. Control subjects were 270 age- and sex-matched patients without a history of stroke and who had undergone cardiac CT. Presence of LA out-pouching structures was determined by ECG-gated cardiac CT. The location of out-pouching structures was categorized as near Bachmann bundle, anterior, inferoseptal, inferior, and lateral. The prevalence, number and location of out-pouching structures and clinical characteristics were compared between the two groups.
  
  
  RESULTS
  One hundred sixty eight out-pouching structures were identified in 139 stroke patients (51%), while a total of 169 out-pouching structures were found in 155 control patients (57%) (p=0.1949). The prevalence of LA out-pouching structures with different locations was not significantly different between the stroke group and control group. In the stroke group, the prevalence of out-pouching structures was not significantly different by subtypes of ischemic stroke and the prevalence of LA out-pouching structures was not different between patients with atrial fibrillation (AF) and without AF.
  
  
  CONCLUSIONS
  The left atrial out-pouching structures are commonly seen in a population with and without stroke with similar prevalence. Our study suggests that LA out-pouching structures are not significant risk factors of stroke.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Ko
authors.forename: Young Dae
authors.initials: YD
authors.lastname: Kim
authors.forename: Yoo Jin
authors.initials: YJ
authors.lastname: Hong
authors.forename: Hye-Jeong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Jin
authors.initials: J
authors.lastname: Hur
authors.forename: Byoung Wook
authors.initials: BW
authors.lastname: Choi
authors.forename: Ji Hoe
authors.initials: JH
authors.lastname: Heo
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Kim
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications / Q000503:physiopathology; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D012042:Registries / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000706:statistics & numerical data; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D014057:Tomography, X-Ray Computed