Efficacy And Safety Of Repeat Ablation Vs.initial Ablation In Atrial Fibrillation:Results From A Six-years Follow-up

Background:Atrial fibrillation(AF)recurrence is common after catheter ablation,with many patients requiring repeat procedures.Few studies reported the prognostic outcomes of redo-ablation,including the risks of recurrence,stroke,and death.Thus,our objective was to assess the efficacy and safety associated with the repeat ablations and investigate the previous ablations as a predictor of AF recurrence in a long-term follow-up.Methods:The retrospective cohort study enrolled consecutive patients who underwent AF ablation at our institution from January 2015 to December 2018 and divided them into the repeat catheter ablation(RECA)and the first-time catheter ablation(FTCA)groups.A follow-up continued for six years with the endpoints of AF recurrence,stroke,and death.Scheduled and symptom-driven 12-lead electrocardiography(ECG)and 24h Holter-monitoring were performed to diagnose AF recurrence,and the recurrence was defined as AP,atrial flutter or atrial tachycardia,lasting ≥30 seconds outside the 90-day blanking period.Results:A total of 867 patients were included in our analysis,of which 78 patients were included in the RECA group and 789 in the FTCA group.Entire cohort was with a mean age of 59.24±10.68 years,male predominance(n=561,64.71%),more commonly with paroxysmal AF(n=763,88.00%),mean duration time 47.56±61.00 months.Only 29(3.34%)patients lost to follow-up.Procedural complications were observed in 32(3.69%)patients involving life-threatening complications:cardiac tamponade and major gastrointestinal bleeding.Over an average of 42.57±15.26 months,AF recurrence occurred in 267(31.86%)patients,40(52.63%)patients in the RECA group compared with 227(29.79%)patients in the FTCA group,P<0.001.This difference was observed not only in one-year recurrence[37.33%(28/75)vs.20.82%(163/783);P=0.001]but also very late recurrence[21.74%(10/46)vs.10.68%(64/599);P=0.023],New-onset stroke and death arose after ablation was equal between the two groups.Kaplan-Meier curves illustrated the significant differences of AF-free survival between RECA and FTCA groups with more risk of AF recurrence linked with patients in the RECA group(log-rank test,P<0.001).By univariate and multivariate Cox regression,we found previous ablation was an independent predictor of AF recurrence.In multivariate Cox regression,patients in RECA group have more risks of AF recurrence with HR=1.731[95%CI(1.171-2.559);P=0.006],have more risks of one-year AF recurrence with HR=1.643[95%CI(1.066-2.531);P=0.024],have more risks of very late AF recurrence with HR=2.213[95%CI(1.132-4.325);P=0.020].Conclusions:The repeat ablation was associated with a significant increase of AF recurrence compared with the first-time procedure,but the endpoints of stroke and death were equal regardless of the number of ablations.Furthermore,the previous ablation predicted AF recurrence independently no matter when the recurrence occurred.