Abstract: Objective To investigate the predictive value of CHADS2 and CHA2DS2- VASc score in left atrial (LA) or left atrial appendage (LAA) thrombus in patients with non-valvular atrial fibrillation (AF). Methods A total of 164 consecu⁃ tive non-valvular AF patients confirmed by transesophageal echocardiography (TEE) were included in this study, and were divided into two groups, LA/LAA thrombus group and non LA/LAA thrombus group. The previous history was recorded in two groups of patients. Their CHADS2 and CHA2DS2-VASC scores were calculated based on the general data of two groups. The laboratory examinations and TEE indexes were compared between two gropes. Results Of all patients, the rate of LA/ LAA thrombus was 19.5%. The CHADS2 and CHA2DS2-VASC scores were significantly higher in LA/LAA thrombus group than those of non LA/LAA thrombus group (2.1±1.3 vs 1.0±0.9, 3.4±1.8 vs 1.9±1.4， P＜0.01). There were 13(11.9%) and 5 (8.8%) patients showed LA/LAA thrombus under low-moderate risk in the two score systems, respectively. Multivariate logis⁃ tic regression analysis showed that CHADS2 score ≥2 points(OR=3.735, 95%CI:1.508-9.251, P=0.004) and CHA2DS2-VASc score ≥2 points (OR=5.104, 95%CI:1.586- 16.425, P=0.006) were independent risk factors of LA/LAA thrombus. ROC curve showed that AUC of CHADS2 and CHA2DS2-VASc scores to predict LA/LAA thrombus were 0.731 (95%CI:0.630- 0.832, P＜0.001) and 0.742 (95%CI:0.640- 0.843, P＜0.001), respectively. Conclusion CHADS2 and CHA2DS2- VASC score ≥2 points are independent risk factors of LA/LAA thrombus in patients with non-valvular atrial fibrillation. The pre⁃ dictive values of both score systems are moderate. There are also LA/LAA thrombus in low-moderate risk patients when us⁃ ing the two score systems, and with the increased risk stratification, the rate of LA/LAA thrombus is increased.

Key words: atrial fibrillation, transesophageal echocardiography, CHADS2 score, CHA2DS2-VASc score, LA/LAA thrombus