Predictive Analysis Of Recurrence After Catheter Ablation Of Atrial Fibrillation

Part I Impact of Mitral Isthmus Anatomy on the SuccessRate of Catheter Ablation of Persistent Atrial FibrillationObjective: Few studies have examined the impact of mitral isthmus (MI) anatomy onthe success rate of radiofrequency catheter ablation (RFCA) of persistent AF. Thepurpose of the study was to identify morphological characteristics of the MI that mayinfluence the outcome of persistent AF patients who underwent RFCA.Methods:96consecutive persistent AF patients (72males) who underwent RFCAprocedure in our center from June,2011to January,2012were enrolled. All patientsunderwent echocardiography and cardiac computed tomography (CT) before catheterablation. When left circumflex artery (LCX) passes through between the MI and theCS, it was defined as “Interposed LCX”. We classified these patients into interposedLCX group and non-interposed LCX group. These patients were followed up2years.Recurrence was defined as any episode of atrial tachyarrhythmias (ATAs), includingAF, atrial flutter or atrial tachycardia, that lasted longer than30seconds after ablanking period of3months.Result: After2years follow-up,60.4%(29/48) in non-interposed LCX group and41.7%(20/48) in interposed LCX group were in sinus rhythm. The success grouphave a lower prevalence of interposed LCX (27.9%VS67.9%, p<0.001), a smallerleft atrial volume (LAV)(126.0±20.4VS136.0±18.0mm3, p=0.013) and a shorter MIdepth (6.8±2.0VS7.6±1.7mm, p=0.033). In multivariable analysis, the patients who have interposed LCX had a1.43-fold (OR:1.43,95%CI:1.22-1.91, p=0.001)increased rate of recurrence; as variables, LAV (OR:2.76,95%CI:2.72-2.80,p=0.0037) was independent predictor of recurrence of AF.Conclusions: Interposed LCX was modest independent risk factor of AF recurrenceafter RFCA. Part II Predictors of recurrence after a repeat ablationprocedure for paroxysmal atrial fibrillation: role of leftatrial enlargementObjective:This study sought to explore the predictors of recurrence in patients withparoxysmal AF undergoing repeat catheter ablation, especially the impact of left atrial(LA) remodeling after the original procedure on the outcome of repeat procedure.Methods: Ninety five patients undergoing repeat ablation were enrolled in this study.Repeat procedure endpoints were pulmonary vein isolation, linear block when linearablation is performed and non-inducibility of atrial tachyarrhythmia by burst pacing.Patients with LA enlargement between pre-original procedure and pre-repeatprocedure were categorized as group1(35pts), while individuals with no change ordecrease of LA diameter were categorized as group2(60pts). The mean durationfrom the original procedure to the repeat procedure was12months (1-40months).Results: After29.6±20.5(3-73) months follow-up from the repeat procedure,33patients experienced recurrence (34.7%). The recurrence rate was significantly higherin group1than in group2(51.4%VS25.0%, P=0.017). In univariable analysis, LAremodeling was the only predictor of recurrence. In multivariate analysis, afteradjustment for age and left ventricular end-diastolic dimension, group1had a greaterrisk of recurrence after repeat procedure (hazard ratio=2.48,95%confidence interval1.18-5.21, P=0.016).Conclusions: LA enlargement after undergoing the original catheter ablation ofparoxysmal AF was an independent risk factor of recurrence after repeat ablation.