Relationship Between Left Atrial Strain Measured By 4D Auto Left Atrial Quantitative Analysis And Embolism Risk In Patients With Non-valvular Atrial Fibrillation

Objective:To explore the relationship between left atrial strain measured by 4D Auto Left Atrial Quantitative（4D Auto LAQ）analysis and embolism risk in patients with non-valvular atrial fibrillation（NVAF）.Methods:We selected a total of 85 patients with NVAF treated in our hospital from August2019 to May 2020.According to the CHA2DS2-VASc score of the patients,women with≥3 scores and men with≥2 scores were divided into thromboembolism high risk group（n=39）,and women with scores<3 and men with scores<2 were divided into thromboembolism low risk group（n=46）.All patients were examined by routine echocardiography,and four-dimensional（4D）left heart images were taken,and left atrial volume and 4D Auto LAQ strain analysis were performed in Echo PAC203software.The differences of left atrial volume and strain between the two groups were compared,and logistic regression analysis was used to determine the independent predictors with the thromboembolism high risk group,and the critical value of this factor for predicting the thromboembolism high risk group was delineated by drawing receiver operating characteristic curves（ROC）of the subjects.Results:（1）LA reservoir strain（LASr）,LA contraction strain（LASct）,LA contraction strain（LASr-c）,LA reservoir circumferential strain（LASr-c）,LA conduit circumferential strain（LAScd-c）,and LA contraction circumferential strain（LASct-c）in patients with NVAF were significantly difference in the thromboembolism high risk group than the low risk group.However,there was no significant difference in the damage degree of Volume at onset of LA contraction（LA Vpre A）and LA ejection fraction（LA EF）between the two groups.（2）LASct-c was an independent risk factor associated with thromboembolism high risk group（OR:2.52）.LASct-c equal to-4.5%is the cut-off value between thromboembolism high risk and low risk in patients with NVAF.LASct-c greater than-4.5%is considered to have a higher thromboembolism risk.（3）because the CHA₂DS₂-VASc score includes many risk factors,such as heart failure,hypertension,diabetes,stroke and embolism,vascular disease and women.Does LASct-c have high accuracy in predicting one or more of the CHA₂DS₂-VASc scores?Taking LASct-c as the test variable,with or without congestive heart failure,hypertension,age≥65 years old,diabetes,stroke or embolism and vascular disease as state variables,the ROC curve was drawn to judge the efficacy of LASct-c.It was found that LASct-c had high efficacy in the diagnosis of embolism and stroke（P<0.001）,AUC:0.909,sensitivity:0.957,specificity:0.823.LASct-c has a certain accuracy in the diagnosis of hypertension,diabetes and age≥65 years old,P values are:<0.001,0.036,<0.001,respectively,AUC:0.804,0.726,0.765 respectively,sensitivity:0.77,0.875,0.676 respectively,and specificity:0.84,0.636,0.833,respectively,LASct-c had no diagnostic efficacy in heart failure and vascular diseases,P values were 0.102 and 0.378 respectively,and AUC were 0.631 and 0.67respectively.Conclusion:Left atrial strain measured by 4D Auto LAQ is a useful index for dynamic evaluation of left ventricular function in patients with NVAF,and it is more sensitive and accurate than left atrial volume.LASct-c is independently associated with thromboembolism high risk group and the value of LASct-c greater than-4.5%is considered to be valuable in guiding anticoagulant therapy in patients with NVAF.