Correlation Of Epicardial Adipose Tissue With Atrial Fibrillation Recurrence After Radiofrequency Ablation

Background:Atrial fibrillation(AF)is the most common cardiac arrhythmia in clinical practice,with high morbidity and disability.As an effective treatment for rhythm control of AF,radiofrequency ablation(RFA)has significant advantages over drug therapy in maintaining sinus rhythm and improving patients’symptoms and quality of life.However,due to individual differences,the treatment results of RFA also vary.Therefore,it is important to effectively identify people at high risk of recurrence to realize the precision of AF treatment strategy and improve the success rate of RFA.Many studies in recent years have shown that epicardial adipose tissue(EAT),a metabolically active visceral adipose tissue between the myocardium and pericardium,can promote the development of AF through mechanisms such as atrial fat infiltration,secretion of pro-fibrotic adipokines,release of inflammatory mediators,and modulation of autonomic nerves,and affect the recurrence of AF because of its directly contact with the myocardium without any fascial separation.The relationship between EAT and recurrence of radiofrequency ablation is a hot topic of medical research at this stage.Objective:This study investigated the association between the respective volume and density of left atrial EAT,as well as total EAT,which measured by left atrial and pulmonary venography(left atrial enhanced CT)in patients with atrial fibrillation and the recurrence after their RFA,aiming to find some new non-invasive surrogate markers which can predict AF recurrence,help clinicians develop individualized treatment strategies and thus improve the success rate of RFA.Methods:This study enrolled patients with AF who had undergone RFA and have had a left atrial and pulmonary venography before the surgery in the Shanghai East Hospital from January 2020 to December 2021.The volume and density of left atrial epicardial adipose tissue and the volume and density of total epicardial adipose tissue were all measured by a software called 3D slicer,then the clinical data before surgery,intraoperative conditions and postoperative follow-up information of the patients were collected through the outpatient and inpatient system retrospectively.All patients were divided into non-recurrence group and recurrence group according to whether AF recurred during the follow-up period of one year after surgery.Baseline data and other EAT-related indicators were compared between the two groups,and logistic regression analysis was used to analyze whether the volume and density of left atrial EAT and the volume and density of total EAT were independent predictors for AF recurrence after RFA,and their value in predicting AF recurrence were evaluated through the receiver operating characteristic(ROC)curves.Results:Patients were strictly screened according to inclusion and exclusion criteria and 124 patients[age,(66.18±10.35)years old;48.4%men]were finally included in the study,including 80 patients(64.5%)with paroxysmal AF.After one year of follow-up,34patients showed recurrence(27.4%).Patients with recurrence after ablation had a significantly higher age(69.71±8.12 vs.64.84±10.82 years old,P=0.019),larger left atrial diameter(LAD)(41.76±5.27 vs.39.81±4.70 mm,P=0.048),higher total EAT density(-85.33±4.57 vs.-87.34±4.49 HU,P=0.028),higher left atrial EAT density(-76.92±4.57 vs.-80.82±5.14 HU,P<0.001)and larger left atrial EAT volume(12.00±4.52 vs.9.71±3.66 cm~3,P=0.004)than those of the non-recurrence group.There was no significant difference in Total EAT volume between non-recurrence group and recurrence group(P=0.061).The left atrial EAT density was significantly higher than the total EAT density in both the non-recurrence and recurrence groups(-80.82±5.14 vs.-87.34±4.49 HU,P<0.001;-76.92±4.57 vs.-85.33±4.57 HU,P<0.001).The correlation analysis of EAT and other indicators showed a moderately strong positive correlation between left atrial EAT volume and LAD(r=0.586,P<0.001).The indicators Age,LAD,left atrial EAT density,left atrial EAT volume and total EAT density with P<0.05 in the univariate analysis were all included in the logistic regression analysis,and the results showed that age(OR=1.070,95%CI:1.008-1.135,P=0.026),left atrial EAT volume(OR=1.231,95%CI:1.066-1.420,P=0.005)and left atrial EAT density(OR=1.177,95%CI:1.045-1.326,P=0.007)were independent predictors of atrial fibrillation recurrence after radiofrequency ablation.ROC curve showed that the area under the curve(AUC)of age,left atrial EAT volume and left atrial EAT density were 0.651,0.659,0.720 on predicting AF recurrence and the best cut-off values were 68.5 years old for age,10.93 cm~3 for left atrial EAT volume and-78.44 HU for left atrial EAT density.The AUC for the combination of left atrial EAT volume and left atrial EAT density to predict AF recurrence was 0.760,and when age was added,the combined AUC of the three indicators increased to 0.798.Conclusion:Age,left atrial EAT volume and left atrial EAT density were independent predictors for recurrence of atrial fibrillation after RFA and their combined indicator could increase the predictive value of AF recurrence.The results of this study suggest that left atrial EAT could be used as a noninvasive imaging marker that can predict atrial fibrillation recurrence to help clinicians optimize treatment strategies and improve the success rate of radiofrequency ablation.It could also be used as a secondary prevention to screen out people who need priority follow-up and then intensify management to reduce the recurrence rate and improve the prognosis of patients.