Analysis of risk factors for thrombosis of the left atrium/left atrial appendage in patients with non-valvular atrial fibrillation

Abstract

Objectives: Left atrial appendage (LAA) morphology is a powerful predictor of thrombogenesis of the left atrium (LA) in patients with non-valvular atrial fibrillation (NVAF). However, it remains unknown whether LAA morphology is useful for stroke risk stratification in patients with NVAF.

Methods: A total of 555 atrial fibrillation patients were divided into thrombus and non-thrombus groups according to transoesophageal echocardiography. We analysed the correlation between LAA morphology and the CHADS₂ score. We determined the L₂CHADS₂ score and compared the ability to predict LA/LAA thrombosis of the CHADS₂, L₂CHADS₂ and CHA₂DS₂-VASc scores from the area under the curve (AUC).

Results: The odds ratio of non-chicken wing LAA morphology was 11.48. Non-chicken wing LAA morphology was significantly correlated with LA/LAA thrombosis. We incorporated LAA morphology into the CHADS₂ score and named it the L₂CHADS₂ score. The AUC of the L₂CHADS₂ score (0.767) in predicting LA/LAA thrombosis was significantly higher than that of the CHADS₂ (0.558) or CHA₂DS₂-VASc scores (0.557). The positive and negative predictive values of the L₂CHADS₂ score (13.1 and 98.7%) were higher than those of the CHADS₂ (8.7 and 94.2%) and CHA₂DS₂-VASc scores (6.9 and 6.9%).

Conclusions: Non-chicken wing LAA morphology was a powerful predictor of LA/LAA thrombosis in NVAF patients. The AUC, sensitivity and specificity of the L₂ CHADS₂ score were higher than those of the CHADS₂ and CHA₂ DS₂ -VASc scores.

Keywords: atrial fibrillation; left atrial appendage morphology; stroke; thrombus.