A prospective randomized single-center study on the risk of asymptomatic cerebral lesions comparing irrigated radiofrequency current ablation with the cryoballoon and the laser balloon.

BACKGROUND: Asymptomatic cerebral lesions (ACL) may occur during atrial fibrillation (AF) ablation. We sought to compare the ACL incidence between 3 contemporary technologies: (1) irrigated radiofrequency current (RFC), (2) the single big cryoballoon (CB), and (3) the endoscopic laser-balloon (LB) in a prospective randomized pilot study. METHODS AND RESULTS: Ninety-nine patients were treated in 3 groups. Diffusion weighted MRI was acquired pre- (n = 20) and 24-48 h postablation (n = 99). After ablation, new ACL were detected in 22% of patients without significant differences between groups (RFC 8/33; CB 6/33; LB 8/33; P = 0.8). The presence of hypertension was identified as the only independent predictor of ACL by univariate regression analysis. During LB ablation, more ablation lesions (140 ± 19 vs 119 ± 18; P = 0.007) were applied during longer procedures (166 ± 36 vs 143 ± 32 min; P = 0.05) in patients with ACL. Univariate analysis revealed that a higher number of ablation lesions predicted ACL (P = 0.02). CONCLUSION: In this prospective, randomized, single-center pilot study, ablation technology did not influence the occurrence of ACL during AF ablation.

Energy titration strategies with the endoscopic ablation system: lessons from the high-dose vs. low-dose laser ablation study.

AIMS: To assess the effects of low-dose (LD) and high-dose (HD) ablation on acute and chronic success in patients with atrial fibrillation (AF). While the concept of visually guided pulmonary vein isolation (PVI) has been established little is known on energy titration using laser ablation. METHODS AND RESULTS: In 60 patients with AF, PVI using the endoscopic ablation system (EAS) was performed in two groups. Visually guided ablation was carried out after obtaining optimal tissue contact with 5.5-8.5 W in the LD group and with >8.5 W in the HD group. Acute PVI after a single visually guided circular lesion set was achieved in 89% (HD) and 69% (LD), respectively, (P = 0.0004). In 70 and 39% of patients all PVs were isolated after a single ablation circle in the HD and LD group, respectively, (P = 0.009). After gap ablation all PVs were isolated with the EAS. More energy was deployed (6483 ± 1834 vs. 5306 ± 2258 Ws; P ≤ 0.0001) with less applications (31.6 ± 8 vs. 35.2 ± 15 applications per PV; P = 0.03) leading to shorter procedure times (128 ± 17 vs. 154 ± 38 min; P = 0.001). During median follow-up of 311 days (261-346) recurrence rate was 17 and 40% in the HD and LD group, respectively. In both groups one phrenic nerve palsy was observed. CONCLUSION: For the first time, it was demonstrated that high ablation power affects acute and chronic outcomes. High-dose laser balloon ablation allows for an acute PVI rate of 89% solely by visually guided circular ablation and is associated with a chronic success rate of 83% after a single procedure.

Visually guided sequential pulmonary vein isolation: insights into techniques and predictors of acute success.

INTRODUCTION: Pulmonary vein isolation (PVI) is a challenging procedure most often requiring sophisticated technical aids such as electroanatomical mapping, double transseptal access, and the use of a circular mapping catheter. We sought to develop a PVI strategy solely based on visual guidance with a single ablation device as well as a single transseptal puncture using the endoscopic ablation system (EAS). METHODS AND RESULTS: In 35 patients with drug-refractory atrial fibrillation (18 male, mean age: 62 ± 9 years) ablation was performed. PVI was achieved in 96 of 137 PVs (70%) purely by visually guided circular ablation. Predictors of acute isolation were the degree of PV occlusion by EAS as well as the number of catheter repositionings but not total ablation energy or the number of laser applications. Conduction gaps were detected at sites with suboptimal occlusion as well as esophageal temperature elevations. Further EAS ablation resulted in a 98% acute isolation rate. Mean procedure and fluoroscopy times were 154 ± 38 minutes and 16 ± 6 minutes, respectively. Between the first and last 12 cases, a reduction in procedure times (175 ± 48 minutes vs 138 ± 26 minutes; P = 0.05) was observed. One pericardial tamponade and 1 right-sided phrenic nerve palsy occurred. During a median follow-up of 266 days (q-q3: 218-389), 27 of 35 patients (77%) remained free of any tachyarrhythmia recurrence off antiarrhythmic drugs. CONCLUSIONS: Sequential PVI based solely on endoscopic visual information with a single device and a single transseptal puncture is feasible. Optimal PV occlusion and few controlled repositionings facilitate PVI.

Single transseptal big Cryoballoon pulmonary vein isolation using an inner lumen mapping catheter.

BACKGROUND: The single big cryoballon technique for pulmonary vein isolation (PVI) has been limited by the need for two transseptal punctures (TP). We therefore investigated feasibility and safety of a simplified approach using a single TP and a novel circumferential mapping catheter (CMC). METHODS: Patients underwent 28-mm cryoballoon PVI using a single TP. The CMC (Achieve(©) Medtronic Inc., Minneapolis, MN, USA) served as (1) guidewire and (2) as a PV mapping tool. Primary endpoint was PVI without switching to a regular guidewire. Secondary endpoints included: (1) PV signal quality during freezing, (2) time to PVI, (3) classification of successful ablation technique, (4) complications, and (5) procedural data. RESULTS: A total of 32 patients (126 PVs) were studied (mean age: 62 ± 11 years, 24 males, left atrium: 40 ± 4 mm). The primary endpoint was achieved in 29/32 patients (91%) and 123/126 PVs (98%) with a procedure and fluoroscopy time of 126 ± 26 minutes and 18.9 ± 7.5 minutes, respectively. Real-time visualization of PVI could be observed in 61/126 (48%) PVs. Time to sustained PVI versus nonsustained PVI was 66 ± 56 seconds versus 129 ± 76 seconds (P < 0.001). One phrenic nerve palsy was observed. After a follow-up of 250 ± 84 days 23/32 patients (72%) remained in sinus rhythm. CONCLUSION: The "simplified single big cryoballoon" PVI strategy appears to be safe and feasible. However, real-time PV recording was achieved in <50% of PVs. Therefore, further catheter refinements are warranted. (PACE 2012; 35:1304-1311).