title: Anatomical characteristics of the left atrial appendage in cardiogenic stroke with low CHADS2 scores.
abstract: BACKGROUND
  Strokes develop even in patients with low CHADS₂ scores, and the left atrial appendage (LAA) is the embolic source 90% of the time. We focused on the LAA morphology as a new predictor of strokes.
  
  
  OBJECTIVE
  To clarify the anatomical characteristics of the LAA for risk stratification of strokes in patients with nonvalvular atrial fibrillation (AF) who have low CHADS₂ scores.
  
  
  METHODS
  Among 80 patients who underwent catheter ablation of AF with contrast-enhanced computed tomography, the LAA characteristics were compared between 30 patients with histories of strokes and 50 age-matched controls. The LAA anatomy was classified into 4 types--"cactus," "cauliflower," "chicken wing," and "windsock"--discriminated by the computed tomography measurements of the length, angle, and number of lobes of the LAA.
  
  
  RESULTS
  The average CHADS₂ score did not differ significantly between patients with stroke and controls (0.8 ± 0.8 vs 0.6 ± 0.7; P = .277). Eight (26.7%) patients with stroke had CHA₂DS₂-VASc scores of 0. The left atrial size, LAA flow velocity, left ventricular function, and serum brain natriuretic peptide level were also unable to predict strokes. However, a "cauliflower" LAA, defined as a main lobe of less than 4 cm long without forked lobes, was significantly more common in patients with stroke (odds ratio 3.857; 95% confidence interval 1.482-10.037; P = .005). The CHA₂DS₂-VASc score-adjusted logistic regression analysis revealed the cauliflower LAA as an independent predictor of a stroke (odds ratio 3.355; 95% confidence interval 1.243-9.055; P = .017).
  
  
  CONCLUSIONS
  The LAA anatomy might be useful for predicting strokes in patients with nonvalvular AF who have low CHADS₂ scores.
authors: Department of Cardiology, Keio University School of Medicine, Tokyo, Japan. kimura@z7.keio.jp
authors: Takehiro
authors: T
authors: Kimura
authors: Seiji
authors: S
authors: Takatsuki
authors: Kohei
authors: K
authors: Inagawa
authors: Yoshinori
authors: Y
authors: Katsumata
authors: Takahiko
authors: T
authors: Nishiyama
authors: Nobuhiro
authors: N
authors: Nishiyama
authors: Kotaro
authors: K
authors: Fukumoto
authors: Yoshiyasu
authors: Y
authors: Aizawa
authors: Yoko
authors: Y
authors: Tanimoto
authors: Kojiro
authors: K
authors: Tanimoto
authors: Masahiro
authors: M
authors: Jinzaki
authors: Keiichi
authors: K
authors: Fukuda
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000473:pathology; D001281:Atrial Fibrillation / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012372:ROC Curve; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D020521:Stroke / Q000453:epidemiology / Q000473:pathology*; D014057:Tomography, X-Ray Computed