Introduction: Catheter ablation of Paroxysmal Atrial Fibrillation (PAF) is associated with an important risk of early and late recurrence, necessitating repeat ablation procedures. The aim of this prospective randomized patient-blind study was to compare the efficacy and safety of Cryoballoon (Cryo) versus Radiofrequency (RF) ablation of PAF after failed initial RF ablation procedure. Methods: Patients with a history of symptomatic PAF after a previous failed first RF ablation procedure were eligible for this study. Patients were randomized to Cryo or RF redo ablation. The primary end-point of the study was recurrence of atrial tachyarrhythmia, including AF and left atrial flutter/tachycardia, after a second ablation procedure at 1 year of follow-up. All patients were implanted with a cardiac monitor (Reveal XT, Medtronic) to continuously track the cardiac rhythm. Patients with an AF burden (AF%) ≤ 0.5% were considered AF-free (Responders), while those with an AF% > 0.5% were classified as patients with AF recurrences (non-Responders). Results: Eighty patients with AF recurrences after a first RF Pulmonary Vein Isolation (PVI) were randomized to Cryo (N = 40) or to RF (N = 40). Electrical potentials were recorded in 77 mapped PVs (1.9±0.8 per patient) in Cryo Group and 72 PVs (1.7±0.8 per patient) in RF Group (p=0.62), all of which were targeted. In Cryo group, 68 (88%) of the 77 PVs were re-isolated using only Cryo technique; the remaining nine PVs were re-isolated using RF. In RF group, all 72 PVs were successfully re-isolated (p=0.003 vs Cryo). By intention-to-treat, 23 (58%) RF patients were AF-free vs 17 (43%) Cryo patients on no antiarrhythmic drugs at one year (p=0.06). Three patients had temporary phrenic nerve paralysis in the Cryo group; the RF group had no complications. Of the 29 patients who had only Cryo PVI without any RF ablation, 11 (38%) were AF-free vs 20 (59%) of the 34 patients who had RF only (p=0.021). Conclusions: When patients require a redo pulmonary vein isolation ablation procedure for recurrent PAF, RF appears to be the preferred energy source relative to Cryo.
Modification of left atrial ganglionated plexi (GP) is a promising technique for the treatment of paroxysmal atrial fibrillation (AF) but its therapeutic efficacy is not established. This study aimed at evaluating the effectiveness of anatomic GP modification by means of an implantable arrhythmia monitoring device.In 56 patients with paroxysmal AF, radiofrequency ablation at anatomic sites, where the main clusters of GP have been identified in the left atrium, was performed. In all patients, an electrocardiogram monitor (Reveal XT, Medtronic Inc., Minneapolis, MN, USA) was implanted before (n = 7) or immediately after (n = 49) AF ablation.Average duration of the procedure was 142 ± 18 min and average fluoroscopy time 20 ± 7 min. In total, 53-81 applications of RF energy were delivered (mean of 18.2 ± 3.8 at each of the four areas of GP ablation). Heart rate variability was assessed in 31 patients. Standard deviation of RR intervals over the entire analyzed period, the root mean square of differences between successive RR intervals, and high frequencies decreased, while HRmin, HRmean, and LF to HF ratio increased immediately postablation; these values returned to baseline 6 months after the procedure. At end of 12-month follow-up, 40 (71%) patients were free of arrhythmia recurrence. Ten patients had AF recurrence, two patients had left atrial flutter, and four patients had episodes of flutter as well as AF recurrence. Duration of episodes of AF after ablation gradually decreased over the follow-up period.Regional ablation at the anatomic sites of the left atrial GP can be safely performed and enables maintenance of sinus rhythm in 71% of patients with paroxysmal AF for a 12-month period.
Introduction: The optimal ablation technique for persistent and longstanding persistent Atrial Fibrillation (AF) is unclear. Both Linear Lesions (LL) and Ganglionated Plexi (GP) ablation have been used, in addition to Pulmonary Vein Isolation (PVI), but no direct comparison of the two methods exists. Methods: Two hundred sixty four consecutive patients with persistent/longstanding persistent AF were randomly assigned to 2 different ablation schemes: PVI+LL (n=132) and PVI+GP ablation (n=132). Consistent Sinus Rhythm (SR) off antiarrhythmic drug was assessed after follow-up of at least 3 years with the use of an implanted monitoring device (IMD). Results: All procedural endpoints were acutely achieved. At 12 months following a single procedure, 47% of patients treated with PVI+LL were in SR compared to 54% of patients treated with PVI+GP (p=0.29). At 3 years, 34% of patients with PVI+LL and 49% of patients with PVI+GP maintained SR (p=0.035). Atrial flutter was more frequent in PVI+LL than in PVI+GP ablation group (18% versus 6%, P=0.002). After a second procedure in 78 patients of the PVI+LL group and 55 patients of the PVI+GP group, the long-term overall success rate was 52% and 68%, respectively (p=0.006). Conclusions: PVI+GP ablation confers superior clinical results with less ablation-related left atrial flutter and reduced AF recurrence compared to PVI+LL at 3 years of follow-up.
Introduction: The aim of this study was to identify if there is a threshold of AF burden during the first months post-ablation obtained through continuous subcutaneous monitoring that can identify patients at risk of subsequent AF recurrences. Methods: 613 patients with symptomatic drug refractory AF (17% with persistent AF) were enrolled in this retrospective analysis. All patients underwent circumferential pulmunary vein isolation (PVI) and were implanted with an ILR for collecting data on AF burden during 12-month follow-up. AF freedom (Responders) was defined as AF%<0.5% during follow-up period. A ROC curve analysis was performed to identify the value of AF burden during the first 2 months post ablation (Blanking Period, BP) that was predictive of late recurrence of AF. Results: After the first ablation procedure, 396 (65%) of the 613 patients were AF-free at 12-month: 346 out of 508 (68%) in the paroxysmal AF group and 50 out of 105 (47%) in the persistent AF group. Using the ROC curve (Fig 1), the specificity corresponding to 90% sensitivity was 75%. The corresponding threshold in the AF burden during the blanking period able to identify patients at risk of late recurrences was 7.1%, corresponding to 102h (= 4.25 days) in AF during the 2 months BP. At the multivariate analysis, a threshold in the AF burden <7.1% during BP was still highly significant (p<0.0001) and the odds of responders/non-responders was 21.5 (10.8 - 42.9). Conclusions: The BP AF pattern predicted response to catheter ablation. An AF burden ≥7.1% assessed by continuous monitoring was a powerful predictor of subsequent AF recurrence after initial ablation, and thus be an appropriate guide for early re-intervention.
