Anatomical characteristics of the left atrial appendage in cardiogenic stroke with low CHADS2 scores

Heart Rhythm. 2013 Jun;10(6):921-5. doi: 10.1016/j.hrthm.2013.01.036. Epub 2013 Feb 4.


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.

MeSH terms

  • Aged
  • Atrial Appendage / diagnostic imaging
  • Atrial Appendage / pathology
  • Atrial Fibrillation / complications
  • Atrial Fibrillation / diagnostic imaging
  • Atrial Fibrillation / surgery
  • Electrophysiologic Techniques, Cardiac
  • Female
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Prognosis
  • ROC Curve
  • Risk Assessment
  • Sensitivity and Specificity
  • Stroke / epidemiology
  • Stroke / pathology*
  • Tomography, X-Ray Computed