Incidence and predictors of left atrial thrombus in patients with atrial fibrillation prior to ablation in the real world of China

BACKGROUND: The present study was to evaluate the value of CHADS2 and CHA2DS2VASC scores on predicting left atrial (LA) or left atrial appendage (LAA) thrombus in atrial fibrillation (AF) patients prior to ablation in the real world of China. METHODS AND RESULTS: A total of 397 patients with non-valvular AF were analyzed to determine the relationship between CHADS2 and CHA2DS2VASC scores and LA/LAA thrombus identified on transesophageal echocardiography prior to radiofrequency ablation(RFA). LA/LAA thrombus was present in 38 patients (9.6%). There was a strong association between higher CHADS2 score or CHA2DS2VASC score and LA/LAA thrombus. No thrombus was identified in patients with CHA2DS2VASC score of 0 regardless of anticoagulation status. However, LA/LAA thrombus was detected in 2.9% patients with CHADS2 score of 0 without adequate anticoagulation, while no thrombus was present in the patients with CHADS2 score of 0 with adequate anticoagulation. Univariate analysis showed that heart failure (LVEF＜50%), LA≥40 mm, diabetes mellitus, previous stroke or TIA, CAD, hypertension, inadequate anticoagulation therapy, CHADS2 score of ≥2 and CHA2DS2VASC score of ≥2 were significantly associated with LA/LAA thrombus. Multivariable Cox regression analysis demonstrated that CHA2DS2VASC score of ≥2 (p = 0.02) and previous stroke or TIA (p = 0.04) were independently associated with LA/LAA thrombus regardless of anticoagulation status. ROC curve analysis showed that higher CHADS2 score and CHA2DS2VASC score could be similarly used to predict the presence of LA thrombus. CONCLUSIONS: Both higher CHA2DS2VASC and CHADS2 scores were associated with LA/LAA thrombus in non-valvular AF patients prior to ablation. Although CHA2DS2VASC score and CHADS2 score had similar value to predict LA/LAA thrombus, CHA2DS2VASc score was better to identify low-risk patients for LA/LAA thrombus than CHADS2 score without anticoagulation. There will be a possibility of performing AF ablation or cardioversion in patients with a CHA2DS2VASC of 0 without TEE or anticoagulation therapy. The safety need to be verified by more multicentre randomized controlled clinical trails.