Nomogram to Predict Left Atrial Appendage Flow Velocity in Atrial Fibrillation

Purpose: The flow velocity of the left atrial appendage (LAA), which is closely linked to thrombus or spontaneous echo contrast of the LAA, is one of the significant risk factors for stroke. Therefore, a non-invasive and effective method for determining LAA flow velocity that is as accurate as transesophageal echocardiography (TEE) would be of significant therapeutic value. The aim of this study was to construct nomograms for predicting lower LAA flow velocity by using non-invasive methods. Patients and methods: Data were obtained from 1910 non-valvular atrial fibrillation (NVAF) patients who underwent TEE. A nomogram was constructed by using univariate and multivariate logistic regression analysis. We calculated the area under the curve to determine how well the risk scores predicted outcomes. Furthermore, the nomogram's performance was evaluated using calibration. Results: In the training and validation groups, reduced LAA flow velocity was recorded in 344 (27.8%) and 302 (44.9%), respectively. Left atrial diameter, previous stroke or transient ischemic attack, left ventricular ejection fraction, hypertension, estimated glomerular filtration rate, and non-paroxysmal AF was found to be independent factors for decreased LAA flow velocity in multivariate analysis, and a nomogram was created by using these variables. In the training and validation groups, the nomogram had strong concordance scores of 0.760 and 0.791 in predicting decreased LAA flow velocity. Conclusion: In this study, a nomogram was constructed that incorporated five characteristics of AF patients. The nomogram may be of great value to predicting LAA flow velocity and provide a new direction for the evaluation of LAA flow velocity or function