A Comparison Of Clinical Effect Between Two Strategies Of Therapy For Catheter Ablation On Patients With Short Course Persistent Atrial Fibrillation

Objective: As a kind of treatment for atrial fibrillation，the effectivenessof radiofrequency catheter ablation has been verified constantly，and widelyapplied clinically in recent ten years. The indication has extended from theparoxysmal AF to the persistent AF. For persistent AF, as the course of thedisease extends，the substrate plays a more important role in the maintainingof AF in duration to atrial electrical/organizational restructure. At present,most electrophysiology centers used to take circumferential pulmonary veinisolation (CPVI）in alliance with roof linear、mitral isthmus linear andtricuspid isthmus linear ablation. Mitral isthmus ablation can especiallyincrease the success rate, but at the same time increase the left atrial macrore-entrant atrial tachycardia so as to reduce therapeutic effect. This study is toevaluate and compare the clinical effect of different strategies of catheterablation therapy on patients with short course persistent AF.Method:56patients with persistent atrial fibrillation（AF）and AF history no longerthan two years were continuously elected to this study. All cases conformed tothe diagnostic criteria of the Expert consensus on AF catheter ablation andbeing treated with radiofrequency catheter ablation.All patients finished thefollow-up visit. They were randomly divided into group A and group Baccording to different catheter ablation strategies. Group A contained24cases，treated with circumferential pulmonary vein isolation （CPVI）+leftatrium （LA） roof linear+mitral isthmus linear+tricuspid isthmuslinear(CPVI+3linear) ablation；Group B contained32cases，treated withCPVI+LA roof linear+tricuspid isthmus linear(CPVI+2linear) ablation. Thebaseline data between the two groups had no statistical difference，such as age、gender structure、the course of atrial fibrillation、mergers of hypertension and organic heart disease scale, preoperative leftatrial diameter （LAD）and left ventricular ejection fraction (LVEF). Twogroups are scheduled to complete the operation strategy as ablation terminal，and during the3months after ablation without lasted for more than30s atrialfibrillation attack defined as ablation success, if not，defined as AF recurrence.All patients were subcutaneous injected of low molecular heparin（LMH）postoperative for anticoagulation for5days, recepted oral anticoagulant（warfarin） for3months, keep the international normalized ratio（INR)2.0-3.0. Applicated anti-arrhythmic drugs for3months, discontinuated if norecurrence. All cases recepted oral proton pump inhibitors for1month.Observed the total ablation time (started from venipuncture), CPVItime (from performed localization of the ostium of the pulmonary vein toLasso electrode confirmed pulmonary vein isolation), linear ablation time,X-ray exposure time between the two groups；compared the incidence ofintraoperative complications、linear block rate. In addition to routine follow-up(18.1±6.3months) by the referring cardiologist, patients were hospitalized at3,6,9,12months following the ablation procedure for clinical interview andambulatory24h dynamic electrocardiogram（DEG）.Compared AF recurrencerate after the first time ablation and incidence of postoperative atrialtachycardia or atrial flutter three months after the first time ablation betweenthe two groups. Continuous variables are expressed as mean±SD except forcount and time variables which are expressed as median and interquartile (IQ)range. Statistical significance was assessed using the unpaired Student’s t-testor Mann–Whitney test if necessary. Categorical variables, expressed asnumbers or percentages, were analysed with the χ2test or Fisher’s exact test.All tests were two-tailed and a P-value <0.05was considered statisticallysignificant.Results:1For group B(CPVI+2linear), the total ablation time（164±19VS 211±24min， P=0.015）、 linear ablation time （48±8VS87±12min，P=0.001）、and x-ray exposure time(24±7VS41±9min，P=0.008）aresignificantly shorter than group A(CPVI+3linear). No statistical difference ofsignificance in CPVI time（51±9VS50±11min,P=1.000）, roof linear blockrate（93.8%VS87.5%，P=0.642）, tricuspid linear block rate（90.6%VS91.7%，P=1.000）, and intraoperative AF termination rate（12.5%VS9.4%，P=1.000） between the two groups.2In group A,16cases(66.7%) attained to mitralvalve linear double block;9patients (56.3%) in addition to the endocardial ablation still need thecoronary sinus （CS）distal ablation. Complications appeared in2cases ofgroup A，both related to mitralvalve linear ablation. Pericardial effusionappeared in1case during the ablation of CS in operation，recovered underintense observation; chest pain intraoperative with ST segment elevationtemporarily appeared in1case, dued to left circumflex spasm comfirmed bycoronary angiography, symptom disappeared after injected calciumantagonists intravascularly.3During the follow-up of18.1±6.3months，group B is found to havesignificant reduction in the incidence of atrial tachycardia/atrial flutter (3.1%vs25%,P=0.035). there was no significant statistical difference in AFrecurrence rate between the two groups (group B40.6%VS group A37.5%, P=0.517).Conclusion:1For patients with persistent AF whose duration less than2years, on thebasis of CPVI, compared with combine the roof linear、mitral isthmus and thetricuspid spondylolysis ablation strategy,only addition in roof linear andtricuspid spondylolysis, can significantly reduce the total ablation time, linearablation time and X-ray exposure time, and reduce the incidence ofintraoperative complications; No statistical difference of significance in CPVItime, roof linear block rate, tricuspid linear block rate, and intraoperative AFtermination rate between the two two strategies.2Postoperative follow-up showed that there is no statistical difference between the two strategies in terms of postoperative atrial fibrillationrecurrence, but CPVI+left roof linear+tricuspid spondylolysis strategy hasless incidence of postoperative atrial tachycardia/atrial flutter, thereforeimprove the postoperative quality of life for patients, at the same time be freeof secondary even multiple ablation.3Comprehensive the above results, this study assume that for patientswith persistent AF whose duration less than2years, adopt CPVI+left rooflinear+tricuspid spondylolysis ablation strategy will attain highereffectiveness and safety. With better comprehensive clinical effectiveness，this strategy is suitable for popularization and application.