| Atrial fibrillation(AF)is the most common cardiac arrhythmia.2019 data show that globally,the number of people with AF is about 59.7 million;in 2050,the number of people with AF in Asia is expected to reach 72 million.The presence of genetic susceptibility,poor lifestyle such as alcohol consumption and smoking,and comorbidities such as hypertension,diabetes mellitus,and respiratory sleep apnea syndrome makes the mechanism of AF complex,and there is a trend toward younger age of onset and complexity of the disease.The occurrence of AF increases the risk of stroke,heart failure and death,which seriously threatens the life and health of patients.How to convert patients’AF rhythm to sinus rhythm(SR)and improve the success rate has been an important topic of attention in the field of AF treatment.Current treatment strategies for the conversion of AF include pharmacotherapy,percutaneous endocardial ablation,and surgical ablation(SA).Class III antiarrhythmic drugs are the most commonly used medications,but long-term use in patients with AF is difficult due to adverse event and efficacy issues.Percutaneous endocardial ablation is currently the first-line intervention for treatment of drug intolerance or ineffectiveness.In paroxysmal AF,percutaneous endocardial ablation has a good success rate;however,in persistent AF(PerAF),the 1-year SR maintenance rate is 40%with percutaneous endocardial ablation and only 60%after multiple percutaneous endocardial ablations.Cox maze procedure is the cornerstone of surgical treatment of AF,resulting in a high rate of SR maintenance in patients with AF.However,the complexity and trauma of Cox maze procedure,as well as the need for cardiopulmonary bypass support,have limited its widespread use in patients with AF.With the development of minimally invasive techniques,a variety of minimally invasive ablation strategies have emerged,including thoracoscopic epicardial ablation,and hybrid ablation(HA).Previous retrospective studies and meta-analyses have shown that the 1-year SR maintenance rate for thoracoscopic epicardial ablation is 63%for PerAF,and the 1-year SR maintenance rate for HA can reach more than 80%.Currently,thoracoscopic epicardial ablation is performed worldwide including pulmonary vein isolation,box lesion,and bi-atrial(BA)ablation,with widely varying clinical outcomes.Guidelines related to the treatment of AF have a Class Ⅱb recommendation for catheter ablation/thoracoscopic epicardial ablation/HA for PerAF,with Level C evidence,and no recommendation for specific ablation lesion set.In response to the above lack of evidence for the clinical efficacy of different thoracoscopic epicardial ablation lesion sets and different interventions,this study first investigated the comparative efficacy of different ablation lesion sets of thoracoscopic epicardial ablation,then evaluated the comparative efficacy of thoracoscopic epicardial ablation versus percutaneous catheter endocardial ablation,and finally evaluated the comparative efficacy of HA versus thoracoscopic epicardial ablation.The purpose of this study is to provide evidence for AF treatment guidelines and clinical decisions,and to explore the best ablation lesion set and ablation strategy for the treatment of PerAF or longstanding PerAF.Chapter 1 Box Lesion Versus Bi-atrial Lesion Set for Atrial Fibrillation During Thoracoscopic Epicardial AblationObjectiveThoracoscopic epicardial ablation with a limited lesion set led to suboptimal results for advanced paroxysmal AF or PerAF.Whether additional right atrial lesions improve the result is unclear.MethodsWe conducted a retrospective study involving 80 consecutive patients with paroxysmal or PerAF,left atrial(LA)dilation(LA diameter>40 mm)and failed prior interventional ablation(40 patients,50%)who underwent thoracoscopic epicardial ablation with box lesions(36 patients)or BA lesion(44 patients)in our institution.The probability of freedom from atrial tachyarrhythmias after the procedures was compared between the box lesion group and BA lesion group.Atrial tachyarrhythmia recurrence was defined as any atrial tachyarrhythmias longer than 30s documented by 24-hour Holter monitoring after the 3-month blanking period.ResultsBaseline differences included more patients with PerAF(86.4%vs 47.2%)and larger left atrium[48.00(44.00-50.75)vs 42.00(41.25-44.00)mm]in BA lesion group.There was no difference in procedural complications between the 2 groups.After a mean follow-up of 32 months,the probability of freedom from atrial tachyarrhythmias off antiarrhythmic drugs(AADs)at 6,12 and 24 months was 77.2%,77.2%and 77.2%in BA lesion group and 69.4%,50.0%and 40.6%in the box lesion group,respectively(P=0.006).After adjustment for AF type and previous interventional ablation,BA lesion was an independent predictor of lower atrial tachyarrhythmia recurrence(HR 0.447,95%Cl 0.208-0.963;P=0.040).ConclusionsCompared with the box lesion set,thoracoscopic epicardial ablation with BA lesion sets might provide better freedom from atrial tachyarrhythmias for paroxysmal or PerAF with LA dilation.Randomized control trials are warranted to confirm the benefit of BA lesion sets in these patients.Chapter 2 Thoracoscopic Surgical Bi-atrial Ablation Versus Catheter Ablation in Patients with Persistent Atrial FibrillationObjectiveLimited randomized controlled studies showed that thoracoscopic surgical LA ablation was not superior to catheter ablation(CA)in patients with PerAF.Right atrium might play an important role in triggering and maintaining AF in patients with PerAF.This study aimed to compare the efficacy of thoracoscopic surgical BA ablation versus CA in patients with PerAF.MethodsPatients with PerAF underwent thoracoscopic surgical BA ablation or CA were included in this study.Propensity score matching(1:2)was applied to select patients in CA group and S A group.The primary endpoint was to compare the probability of freedom from atrial tachyarrhythmias between SA and CA off AADs.Atrial tachyarrhythmia recurrence was defined as any atrial tachyarrhythmias longer than 30s documented by 24-hour Holter monitoring after the 3-month blanking period.ResultsAfter propensity score matching,51 patients in SA group and 102 patients in CA group were enrolled(mean LA diameter:45.8mm).The probability of freedom from atrial tachyarrhythmias on AADs was 62.7%,60.6%and 60.6%in SA group and 42.0%,39.6%,and 36.7%in CA group at 12,24,and 36 months,respectively(P=0.011),and off AADs was 56.9%,52.5%and 52.5%in SA group and 36.0%,31.4%and 27.5%in CA group at 12,24,and 36 months,respectively(P=0.007).Perioperative complications occurred in four patients(7.8%)in SA group and in three patients(2.9%)in CA group(P=0.223).ConclusionsCompared with CA,thoracoscopic surgical BA ablation might achieve superior effectiveness for patients with PerAF.Chapter 3 One-stage Hybrid Ablation Versus Thoracoscopic Surgical Ablation for the Treatment of Atrial FibrillationObjectiveThoracoscopic epicardial SA has shown unsatisfactory results for the treatment of longstanding persistent AF(LSPAF)and/or PerAF with enlarged left atrium.HA with epicardial surgical and endocardial CA has shown promising efficacy in AF.This study aimed to verify whether HA was superior to SA as the first interventional strategy in LSPAF or PerAF with enlarged left atrium.MethodsPatients with LSPAF or PerAF with enlarged left atrium were randomized to HA or SA at a 1:1 allocation ratio.The primary endpoint was the probability of freedom from any recurrence of AF off AADs 12 months after operation.Secondary endpoints included the probability of freedom from any recurrence of atrial tachyarrhythmias on/off AADs 12 months after operation,procedure-associated adverse events,AF burden,quality of life,cardiac function,and major adverse cardiovascular and cerebral events.The primary endpoint events were monitored by 7-day electrocardiogram monitoring devices,ResultsOne hundred patients were enrolled.The mean age was 58.5±7.6 years,and the mean LA diameter was 50.1±6.1 mm.At 12 months,freedom from AF was recorded in 71.4%(35/49)of patients in HA group and 45.8%(22/48)in SA group[OR 2.955,95%CI(1.275-6.848),P=0.014].There was no significant difference in procedure-associated adverse events between the two groups(8.2%in HA group and 2.1%in SA group,P=0.362).Compared with SA,HA significantly reduced patients’ AF burden(30.2%in SA group and 14.8%in HA group,P=0.048)and the LA diameter(mean differences:-5.53±4.97mm in HA group and-3.27±5.20mm in SA group,P=0.037)at 12 months after operation.ConclusionsIn patients with LSPAF or PerAF with enlarged left atrium,HA is superior to SA in achieving freedom from AF after 12 months of follow-up. |
