Characteristics Of Epicardial Fat And Its Relationship With Prognosis After Radiofrequency Ablation

The relationship between epicardial fat.and clinical diseases such as coronary atherosclerotic heart disease,chest pain,unstable angina,coronary flow reserve,hepatic steatosis,atrial fibrillation,and heart failure has been extensively studied.Recent studies have shown that the fat attenuation index(FAI)of epicardial fat.on CT is more accurate than that of coronary angiography and predicts acute myocardial infarction in advanc.e.OBJECTIVE:To find out.the distribution characteristics of epicardial fat.in patients with atrial fibrillation complicated with different diseases,and to verify whether the characteristics of epicardial fat are risk factors for recurrence of atrial fibrillation after radiofrequency ablation of cardiac surgery、METHODS:Ninety-nine patients underwent radiofrequency ablation of atrial fibrillation in Fuwai Hospital from January 2017 to December 31 2018 were enrolled,of which 97 underwent cardiac CT examination before operation.Pulmonary vein area,left atrium,right atrium and whole heart were modeled by cardiac CT.According to epicardial fat density,pulmonary vein area,left atrium,right atrium and whole heart epicardial fat model were established.The clinical data,intraoperative and postoperative follow-up data of all patients were collected,and the relat ionship between them and the imaging characteristics of the model was calculated.The distribution characteristics of epicardial fat in atrial fibrillation patients with different diseases were found.COX regre.ssion analysis of atrial fibrillation after radiofrequency ablation using SPSS to identify the risk factors of atrial fibrillation aft er radiofrequency ablation.RESULTS:The gray level of epicardial fat in all sites ranged from-80 to-60,and that of left atrial fat ranged from-80 to-60 accounted for a larger proportion than that of other locations.For patients with hypertension,there were significant differences in the mean density of left atrial adipose tissue,the mean density of whole heart adipose tissue,the volume of pulmonary vein adipose tissue and the volume of left atrial adipose tissue(p<0.05).There.were signific.ant differences in the proportion of fat in left atrium between the two groups in the gray scale of each adipose tissue(p<0.05),but there were no significant differences in the area of pulmonary vein,right atrium and whole heart.There were significant differences in pulmonary vein fat volume,left atrium fat volume,total pulmonary vein volume,total left atrium volume and total right atrium volume between the two groups(p<0.05).There were no significant differences in the proportion of fat in pulmonary vein,left atrium,right atrium and whole heart between the two groups(p>0.05).For patients with paroxysmal atrial fibrillation,there were significant differences in pulmonary vein fat volume,left atrial fat volume and right atrial fat volume between the two groups(p<0.05).There were no significant differences in the proportion of fat in pulmonary vein,left atrium,right atrium and whole heart between the two groups(p>0.05).The onset time of atrial fibrillation was not correlated with the volume and gray scale of epicardial fat in left atrium,right atrium,pulmonary vein and whole heart.Univariate COX regression analysis showed that the proportion of right atrial fat gray scale in-180 to-160HU,the average gray scale of right atrial fat,the proportion of right atrial fat gray scale in-160 to-140 HU,the proportion of left atrial fat gray scale in-195 to-180 HU,the proportion of right atrial fat gray scale in-195 to-180 HU,the proportion of left atrial fat gray scale in-180 to-160HU,the proportion of left atrial fat gray scale in-160 to-140 HU,and the gray scale of left atrial fat in-80 to-60 HU.The risk factors of AF recurrence after operation were the proportion of U,the proportion of whole heart fat gray,the proportion of whole heart fat gray,the proportion of whole heart fat gray from-160 to-140 HU,the proportion of whole heart fat gray from-180 to-160 HU,the proportion of pulmonary vein fat gray from-160 to-140 HU,the average gray of pulmonary vein fat and the proportion of right atrial fat gray from-60 to-45 HU,P<0.05.Univariate regression analysis and multivariate regression analysis were used to analyze the recurrence of epicardial fat and atrial fibrillation in four different locations of the heart.Three models were used for multivariate analysis.The correction factors were:1.BMI,BSA,left atrial fat gray scale,the onset time of atrial fibrillation,and the significant risk of univariate regression analysis.Factors(left atrial diameter,past medical ablation history,hypertension);2.Multivariate regression analysis compared with left atrial fat volume,correction factors:left atrial fat volume,left atrial fat gray scale,onset time of atrial fibrillation,single factor regression analysis of significant risk factors(left atrial diameter,past medical ablation history,hypertension)3.Compared with the traditional regression analysis model of risk factors of atrial fibrillation,correction factors:BMI,BSA,left atrial fat volume,onset time of atrial fibrillation,single factor regression analysis of significant risk factors(left atrial diameter,past medical ablation history,hypertension).The results showed that the average gray level of left atrial fat was a risk factor for recurrence of AF after radiofrequency ablation of atrial fibrillation(P<0.05).The average gray level of left atrial adipose tissue was divided into three groups:high,medium and low.The Kaplan-Meier test showed that the cumulative incidence of left atrial adipose tissue was significantly different among the three groups.Log Rank(Mantel-Cox)P=0.011.Conclusion:The distribution characteristics of epicardial fat in patients with atrial fibrillation complicated with different diseases are different.Compared with the conventional risk factors and the volume of epicardial fat after radiofrequency ablation,the CT gray scale of left atrial epicardial fat can better reflect the recurrence of atrial fibrillation after radiofrequency ablation.