Importance of left atrial appendage flow as a predictor of thromboembolic events in patients with atrial fibrillation

Eur Heart J. 1999 Jul;20(13):979-85. doi: 10.1053/euhj.1998.1453.

Abstract

Aim: The purpose of this study was to investigate the role of transoesophageal echocardiography in predicting subsequent thromboembolic events in patients with atrial fibrillation.

Methods and patients: Transoesophageal echocardiography was performed in 88 patients with documented paroxysmal (n=53) or chronic atrial fibrillation (n=35) to assess morphological and functional predictors of thromboembolic events. Prospective selection was from patients with non-valvular atrial fibrillation who had undergone transoesophageal echocardiography because of previous thromboembolism (n=30); prior to electrical cardioversion (n=31); or for other reasons (n=27). All patients were followed up for 1 year.

Results: During the period of follow-up new thromboembolic events occurred in 18 of 88 patients (20%/year); 16 of these patients had a stroke and two a peripheral embolism. Univariate analysis revealed that previous thromboembolism (P<0.005; odds ratio 5.3 [CI 1.9, 12. 1]), history of hypertension (P<0.01; odds ratio 4.0 [CI 1.4, 10.4), presence of left atrial spontaneous echo contrast (P<0.025; odds ratio 3.5 [CI 1.2, 10.0]), and presence of left atrial appendage peak velocity </=0.20 m. s-1(P<0.01; odds ratio 4.1 [CI 1.4, 11.6]) were significantly related to subsequent thromboembolic events. Stepwise logistic regression showed that independent predictors of thromboembolic events were: history of thromboembolism (P<0.005), history of hypertension (P<0.05) and low left atrial appendage peak velocity </=0.20 m. s-1(P<0.01).

Conclusions: In patients with atrial fibrillation, the presence of spontaneous echo contrast in the left atrium, and in particular a low left atrial appendage peak flow velocity, can be used to identify a subgroup of atrial fibrillation patients at either increased or decreased risk of subsequent thromboembolism, which might have important implications for anticoagulation therapy.

MeSH terms

  • Aged
  • Atrial Fibrillation / complications*
  • Atrial Fibrillation / diagnostic imaging
  • Atrial Function, Left*
  • Coronary Circulation*
  • Coronary Thrombosis / etiology
  • Coronary Thrombosis / physiopathology*
  • Echocardiography, Doppler, Pulsed
  • Echocardiography, Transesophageal
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Regional Blood Flow
  • Risk Factors