| Part Ⅰ A CCTA study on relationship between the secondary changes in size and function of left atrial appendage and the progression of disease in patients with non-valvular atrial fibrillationObjective:To investigate relationship between the secondary changes in size and function of left atrial appendage and the progression of nonvavular atrial fibrillation(NVAF)in patients with NVAF using coronary computed tomography angiography(CCTA)examination.Methods:1.Select the patients with NVAF that matches gender,age,body surface area(BSA),body mass index(BMI),atrial fibrillation type(paroxysmal atrial fibrillation vs persistent or permanent atrial fibrillation,the same below).Patients with NVAF were divided into 4 groups according to duration years of atrial fibrillation:≤2 years group(49 cases),3 to 4 years group(46 cases),5 to 8 years group(48 cases),≥9 years group(46 cases),Among the patients without a history of atrial fibrillation who underwent CCTA examination during the same period,45 patients with matching gender,age,BSA,and BMI were selected as the non-AF group;2.Collect the CCTA examination data of the above 5 groups of study subjects,use the cardiac function analysis software to measure the left atrial appendage opening length and short diameter(LAAODmax,LAAODmin),opening area(LAAOA),depth(LAAD),maximum and minimum volume(LAAVmax),LAAVmin)and other parameters.Use BSA to calibrate each measurement parameter,obtain the value index of the parameter,and perform data processing;3.Using the 2×C contingency table χ2 test and one-way analysis of variance,the differences between the baseline indicators and the left atrial appendage CCTA measurement parameters of the 5 groups were compared;4.After analysis of variance,compare the left atrial appendage CCTA measurement parameters between groups;5.Spearman correlation analysis was used to evaluate the correlation between left atrial appendage CCTA measurement parameters and the duration years of atrial fibrillation.Results:1.There were no statistical differences in gender,age,BSA,overweight or obesity(BMI≥ 25)in each group(P>0.05),and there was no statistical difference in atrial fibrillation type between groups with different duration years of atrial fibrillation history(P=0.956);the differences in LAAODmax Index,LAAODmin Index,LAAOA Index,LAAD Index,LAAVmax Index,LAAVmin Index,and LAAEF between the groups are all statistically significant(P<0.001),and there is no statistically significant LAAODmax/min among the groups Difference(P=0.291);2.Pairwise comparisons between groups show that groups with more duration years of atrial fibrillation history are less than those with fewer years(or without atrial fibrillation),except that LAAEF is reduced to varying degrees,LAAODmax Index,LAAODmin Index,LAAOA Index,LAAD Index,LAAVmax Index The value of LAAVmin Index increased to varying degrees,and most of the differences were statistically significant(P<0.05);3.Spearman correlation analysis showed that LAAOA Index(rs=0.642,P<0.001),LAAVmin Index(rs=0.731,P<0.001)were highly positively correlated with,the duration years of atrial fibrillation and LAAEF was highly negatively correlated with the duration years of atrial fibrillation(rs=-0.725,P<0.001);LAAODmax Index(rs=0.584,P<0.001),LAAODmin Index(rs=0.551,P<0.001),LAAVmax Index(rs=0.550,P<0.001)and the duration years of atrial fibrillation The degree is positively correlated;LAAD Index is positively correlated with the duration years of atrial fibrillation(rs=0.269,P<0.001).Conclusions:1.In NVAF patients,the left atrial appendage opening and volume gradually increase with the prolonged history of atrial fibrillation,and the pumping and emptying function of the left atrial appendage is progressively impaired and decreased;2.The secondary changes in the size and function of the left atrial appendage reflect the mutual promotion of pathological mechanisms between the progression of atrial fibrillation and the remodeling and hemodynamic changes of the left atrial appendage;3.The CCTA examination is simple and easy to perform.It can provide a more accurate quantitative evaluation index for the size and function of the left atrial appendage of NVAF patients,with high feasibility and clinical application value.Part Ⅱ The role of CCTA in the study of the predictive value of left atrial appendage measurements for cardiogenic stroke risk in non-valvular atrial fibrillation patientsObjective:Using CCTA examination to investigate the predictive value of changes in the size and function of left atrial appendage for cardiogenic stroke(CS)risk in NVAF patients.Methods:1.Select 179 patients with NVAF and group them according to the incidence of acute ischemic stroke and transient ischemic attack(TIA)within 2 years after the CCTA examination.Among them,those meet the CS criteria are regarded as the case group(CS group,87 cases),those with neither acute ischemic stroke nor TIA as the control group(92 cases);2.Collect the clinical and examination data of the above two groups of patients.Use cardiac function analysis software to measure the left atrial appendage opening length and short diameter and area,depth,volume and other parameters,through body surface area(BSA)correction,to obtain the correction index(Value Index)of this parameter;3.Select the corresponding statistical test methods according to different numerical data types,and compare the differences in clinical baseline data indicators and CCTA measurement parameters between the two groups of subjects;4.Group the LAAOA Index and LAAEF into four equal groups,and use binary Logistic regression to evaluate Body Mass Index(BMI),hyperlipidemia,atrial fibrillation history,LAAOA Index,LAAOA Index,left atrial ear shot The influence of blood fraction(LAAEF)on the pathogenesis of CS;5.According to the logistic regression analysis results,draw the receiver operating characteristic(ROC)curve of LAAOA Index,LAAEF single index and the two-index combined predictor(LAAOA Index-LAAEF)to determine the best diagnostic cutoff(cut-off),evaluate and compare the predictive value of LAAOA Index,LAAEF single index and the two index combined predictor(LAAOA Index-LAAEF)on the incidence of CS.Results:1.The proportion of overweight or obesity,the prevalence of hyperlipidemia,and the number of years of atrial fibrillation in the CS group were greater than those in the control group,and the difference was statistically significant(P<0.05).Gender,age,history of smoking,history of drinking,hypertension,diabetes,coronary heart disease,CHA2DS2VASc score,the proportion of continuous use of anticoagulants during the follow-up period,and the type of atrial fibrillation(paroxysmal atrial fibrillation vs persistent or permanent atrial fibrillation))There is no statistical difference(P>0.05);2.The left atrial appendage opening long diameter and short diameter(LAAODmax,LAAODmin),opening area(LAAOA),maximum and minimum volume(LAAVmax,LAAVmin)and their respective correction indexes in the CS group were greater than those in the control group(P<0.001).The left atrial appendage in the CS group The atrial appendage ejection fraction(LAAEF)was lower than that of the control group,and the difference was statistically significant(P<0.001).The left atrial appendage opening length-to-short diameter ratio(LAAODmax/LAAODmin),left atrial appendage depth(LAAD)and its correction index(LAAD Index)were not statistically different between the two groups(P>0.05);3.Binary Logistic Regression Analysis Results3.1 LAAOA Index(P=0.005)and LAAEF(P<0.001)are statistically significant,while BMI(P=0.173),hyperlipidemia(P=0.222)and the number of years of atrial fibrillation(P=0.059)are not statistically significant;3.2 Logistic regression model is statistically significant(χ2=42.250,P<0.001).After adjusting the number of years of BMI,hyperlipidemia and atrial fibrillation,the model shows that the increase in LAAOA Index and the decrease in LAAEF are independent risk factors for the onset of CS in NVAF patients;3.3 The risk of CS in the highest value group of LAAOA Index was 5.826 times that of the lowest value group(95%CI=2.167-15.661,P<0.001).The lowest value group and the second lowest value group of LAAEF were 8.255 times higher than the highest value group.(95%CI=2.929-23.264,P<0.001)and 3.081 times(95%CI=1.166-8.139,P=0.023);3.4 The Logistic regression model can correctly classify 71.5%of the research objects.The sensitivity of the model is 70.1%,the specificity is 72.8%,the positive predictive value is 70.9%,and the negative predictive value is 72.0%.4.ROC curve analysis results4.1 The area under the ROC curve(AUC)of LAAOA Index is 0.712(95%CI=0.639-0.777,P<0.0001),and the best diagnostic cut-off(cut-off)is 3.16 cm2/m2(sensitivity is 54.0%,specific Degree is 78.3%);4.2 The AUC value of LAAEF is 0.734(95%CI=0.663-0.797,P<0.0001),and the cut-off value is 38.7%(sensitivity is 62.1%,specificity is 75.0%);4.3 The AUC value of the combined predictor LAAOA-LAAEF is 0.786(95%CI=0.718-0.843,P<0.0001);4.4 ROC curve pairwise comparison results show:LAAOA Index-LAAEF and LAAOA Index(0.074,P=0.008)and LAAEF(0.052,P=0.039)the difference of the area under the ROC curve is statistically significant,LAAOA Index and LAAEF ROC The difference of the area under the curve(0.0221,P=0.6544)was not statistically significant.Conclusions:1.Increased LAAOA Index and decreased LAAEF are independent risk factors for the onset of CS in NVAF patients;2.LAAOA Index and LAAEF have predictive value for the onset of CS in NVAF patients,and the combination of two indicators can improve the accuracy of prediction;3.CCTA can provide more accurate imaging quantitative indicators for the risk assessment of CS in NVAF patients.Part Ⅲ The value of left atrial appendage CCTA measurement in predicting cardiogenic stroke in patients with non-valvular atrial fibrillation with different risk levels of CHA2DS2-VASc scoreObjective:Using CCTA to evaluate the predictive value of changes in the size and function of the left atrial appendage in NVAF patients with different risk levels of CHA2DS2-VASc score for the outbreak of CS.Methods:1.Use the clinical data and CCTA measurement data of the left atrial appendage of the Part Ⅱ of this research project in the case group(CS group,87 cases)and the control group(92 cases);2.Collect CHA2DS2-VASc score data of the two groups of subjects for analysis and processing2.1 Investigate the number of cases of each scoring item of CHA2DS2-VASc in the CS group and the control group;2.2 Investigate the number of cases with low-risk(0 score),intermediate-risk(1 score)and high-risk(≥2 score)CHA2DS2-VASc scores in the CS group and the control group;2.3 According to the CHA2DS2-VASc score value,all the study subjects were divided into two groups of low-medium risk(0-1 score)and high-risk(≥2 score),and the two groups of LAAOA Index and LAAEF index data were counted.3.Choose an appropriate test method according to the type of numerical data,and compare the differences in clinical baseline data and CCTA measurement parameters between the two groups;4.Pearson chi-square test was used to compare the differences of CHA2DS2-VASc scoring items between the two groups;5.The 2×C contingency table χ2 test was used to compare the differences in the incidence of CS among patients with different risk levels of CHA2DS2-VASc scores,and the Bonferroni method was used to adjust the significance level for pairwise comparison;6.Draw the receiver operating characteristic curve(ROC)of the low-risk and high-risk two groups of patients with CHA2DS2-VASc score,LAAOA Index,LAAEF,and the two index combined predictor(LAAOA Index-LAAEF),and determine the best diagnostic cutoff(cut-off),to evaluate and compare the predictive value of left atrial appendage CCTA measurement indicators on the risk of CS in NVAF patients with different risk levels of CHA2DS2-VASc score.Results:1.The proportion of overweight or obesity,the prevalence of hyperlipidemia,and the number of years of atrial fibrillation in the CS group were greater than those in the control group.The difference was statistically significant(P<0.05).The gender,age,smoking history,drinking history,and high There were no significant differences in blood pressure,diabetes,coronary heart disease,CHA2DS2VASc score,the proportion of continuous use of anticoagulants during the follow-up period,and the type of atrial fibrillation(paroxysmal vs persistent or permanent atrial fibrillation)(P>0.05).The LAAOA,LAAOA Index,LAAVmax,and LAAVmin of the CS group were higher than those of the control group,and LAAEF was lower than the control group,the difference was statistically significant(P<0.001);2.Among the CHA2DS2-VASc scoring items,the CS group had a high incidence of previous cerebral infarction/TIA/thromboembolism(47.1%vs 26.1%,P=0.003)and vascular disease(71.3%vs 47.8%,P=0.001)In the control group,the difference was statistically significant.There was no statistically significant difference in the incidence of other scoring items between the two groups(P>0.05);3.There was a statistically significant difference in the incidence of CS among patients with different risk levels of CHA2DS2-VASc score(P=0.019).Pairwise comparisons showed that there was a statistically significant difference in the incidence of CS between the low-risk and intermediate-risk groups,and between the low-risk and high-risk groups(P=0.006 and P=0.011),and the difference between the intermediate-risk and high-risk groups was not statistically significant(P=0.463);4.ROC curve analysis of left atrial appendage CCTA measurement indicators in the low-risk and high-risk groups of CHA2DS2-VASc score4.1 Area under the ROC curve(AUC)and the best diagnostic cut-off(cut-off)4.1.1 CHA2DS2-VASc score middle and low risk group(0～1 score)(1)The area under the ROC curve of LAAOA Index is 0.701(95%CI=0.552-0.825,P<0.0001),and the cut-off value is 2.21 cm2/m2(sensitivity is 86.4%,specificity is 50.0%);(2)The area under the ROC curve of LAAEF is 0.804(95%CI=0.664-0.905,P<0.0001),and the cut-off value is 46.5%(sensitivity is 72.7%,specificity is 76.9%);(3)The area under the ROC curve of LAAOA Index-LAAEF is 0.837(95%CI=0.703-0.928,P<0.0001);(4)Pairwise comparison of ROC curves in low-and medium-risk groups:1)The difference between the area under the curve of LAAOA Index-LAAEF and LAAOA Index is 0.136,which is statistically significant(Z=2.145,P=0.0319);2)The difference between the area under the curve of LAAOA Index-LAAEF and LAAEF is 0.0332,the difference is not statistically significant(Z=0.887,P=0.3751);3)The difference between the area under the ROC curve of LAAOA Index and LAAEF was 0.103,the difference was not statistically significant(Z=1.145,P=0.2524).4.1.2 CHA2DS2-VASc score high-risk group(≥2 score)(1)The area under the ROC curve of LAAOA Index is 0.723(95%CI=0.638-0.798,P<0.0001),and the cut-off value is 3.02 cm2/m2(sensitivity is 67.7%,specificity is 68.2%);(2)The area under the ROC curve of LAAEF is 0.714(95%CI=0.629-0.790,P<0.0001),and the cut-off value is 38.5%(sensitivity is 69.2%,specificity is 66.7%);(3)The area under the ROC curve of LAAOA Index-LAAEF is 0.793(95%CI=0.714-0.859,P<0.0001);(4)Pairwise comparison of ROC curves of high-risk groups:1)The difference between the area under the curve of LAAOA Index-LAAEF and LAAOA Index is 0.0697,the difference is statistically significant(Z=2.222,P=0.0263);2)The difference between the area under the curve of LAAOA Index-LAAEF and LAAEF is 0.0790,the difference is statistically significant(Z=2.204,P=0.0275);3)The difference between the area under the ROC curve of LAAOA Index and LAAEF was 0.00932,the difference was not statistically significant(Z=0.151,P=0.8800).4.2 The paired comparison of the ROC curve of the CCTA measurement index between the low-risk and high-risk groups in the CHA2DS2-VASc score(1)The difference in the area under the curve of LAAOA Index between the two groups was-0.022,the difference was not statistically significant(Z=-0.252,P=0.8013);(2)The difference in the area under the curve of LAAEF between the two groups was 0.090,the difference was not statistically significant(Z=1.170,P=0.2418);(3)The difference in the area under the curve of LAAOA Index-LAAEF between the two groups was 0.044,and the difference was not statistically significant(Z=0.630,P=0.5290).Conclusions:1.CHA2DS2-VASc score risk stratification cannot accurately reflect the risk of cardiogenic thrombosis in NVAF patients;2.In terms of predicting the risk of CS in NVAF patients,the two CCTA measurement indicators LAAOA Index and LAAEF can be used as a useful supplement to CHA2DS2-VASc score;3.LAAOA Index and LAAEF have the same value for predicting the risk of CS in NVAF patients with low-and medium-risk CHA2DS2-VASc scores(0-1 score)and high-risk scores(≥2 score). |
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