Development and Validation of a Nomogram for Estimation of Left Atrial Thrombus or Spontaneous Echo Contrast Risk in Non-Valvular Atrial Fibrillation Patients with Low to Borderline CHA2DS2-VASc Score

Zhitong Li1 *, Lifei Pan1 *, Yawen Deng,1 Quanbo Liu,2 Tesfaldet H Hidru,1 Fei Liu,1 Chenglin Li,1 Tao Cong,1 Xiaolei Yang,1 Yunlong Xia1 1Department of Cardiology, First Affiliated Hospital of Dalian Medical University, Dalian, People’s Republic of China; 2Department of Respiratory Medicine, Shengjing Hospital of China Medical University, Shenyang, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiaolei Yang; Yunlong Xia, Email 15942456079@yeah.net; yunlong_xia@126.comPurpose: Left atrial thrombus (LAT)/left atrial spontaneous echo contrast (LASEC) still exists in CHA2DS2-VASc score-defined low/borderline risk population. The purpose of this study is to explore the risk factors that associate with LAT/SEC and to create a nomogram to predict LAT/SEC risk in NVAF patients with low/borderline CHA2DS2-VASc scores.Patients and Methods: A total of 834 NVAF patients with complete data on transesophageal echocardiography (TEE) were included in this study. Univariate and multivariate logistic regression analyses were performed to identify the risk factors that associate with LAT/SEC, and a nomogram was established based on the results. Receiver operating characteristic curve (ROC), calibration curve and decision curve analysis were performed to verify the predictive power of nomogram.Results: The rates for LAT/SEC for the training and validation cohorts were 84 (14.7%) and 30 (11.4%), respectively. Independent factors including age, left ventricular ejection fraction (LVEF), left atrial diameter (LAD), smoke, non-paroxysmal AF (NPAF), and E/e’ were considered to construct the nomogram for LAT/SEC. The AUC for nomogram was 0.839 and 0.811 in the training and validation cohorts, respectively. The calibration and decision curve analysis showed that the nomogram had a good prediction capacity and would be clinically useful.Conclusion: Age, LVEF, LAD, smoke, NPAF, and E/e’ are independently associated with LAT/SEC in NVAF patients with low/borderline CHA2DS2-VASc scores. The nomogram that incorporates these six variables effectively predict LAT/SEC risk in NVAF patients with low/borderline CHA2DS2-VASc scores.Keywords: left atrial thrombus, spontaneous echo contrast, atrial fibrillation, nomogram, CHA2DS2-VASc score