Catheter ablation is less successful for persistent atrial fibrillation than for paroxysmal atrial fibrillation. Guidelines suggest that adjuvant substrate modification in addition to pulmonary-vein ...isolation is required in persistent atrial fibrillation.
We randomly assigned 589 patients with persistent atrial fibrillation in a 1:4:4 ratio to ablation with pulmonary-vein isolation alone (67 patients), pulmonary-vein isolation plus ablation of electrograms showing complex fractionated activity (263 patients), or pulmonary-vein isolation plus additional linear ablation across the left atrial roof and mitral valve isthmus (259 patients). The duration of follow-up was 18 months. The primary end point was freedom from any documented recurrence of atrial fibrillation lasting longer than 30 seconds after a single ablation procedure.
Procedure time was significantly shorter for pulmonary-vein isolation alone than for the other two procedures (P<0.001). After 18 months, 59% of patients assigned to pulmonary-vein isolation alone were free from recurrent atrial fibrillation, as compared with 49% of patients assigned to pulmonary-vein isolation plus complex electrogram ablation and 46% of patients assigned to pulmonary-vein isolation plus linear ablation (P=0.15). There were also no significant differences among the three groups for the secondary end points, including freedom from atrial fibrillation after two ablation procedures and freedom from any atrial arrhythmia. Complications included tamponade (three patients), stroke or transient ischemic attack (three patients), and atrioesophageal fistula (one patient).
Among patients with persistent atrial fibrillation, we found no reduction in the rate of recurrent atrial fibrillation when either linear ablation or ablation of complex fractionated electrograms was performed in addition to pulmonary-vein isolation. (Funded by St. Jude Medical; ClinicalTrials.gov number, NCT01203748.).
Current guidelines recommend pulmonary-vein isolation by means of catheter ablation as treatment for drug-refractory paroxysmal atrial fibrillation. Radiofrequency ablation is the most common method, ...and cryoballoon ablation is the second most frequently used technology.
We conducted a multicenter, randomized trial to determine whether cryoballoon ablation was noninferior to radiofrequency ablation in symptomatic patients with drug-refractory paroxysmal atrial fibrillation. The primary efficacy end point in a time-to-event analysis was the first documented clinical failure (recurrence of atrial fibrillation, occurrence of atrial flutter or atrial tachycardia, use of antiarrhythmic drugs, or repeat ablation) following a 90-day period after the index ablation. The noninferiority margin was prespecified as a hazard ratio of 1.43. The primary safety end point was a composite of death, cerebrovascular events, or serious treatment-related adverse events.
A total of 762 patients underwent randomization (378 assigned to cryoballoon ablation and 384 assigned to radiofrequency ablation). The mean duration of follow-up was 1.5 years. The primary efficacy end point occurred in 138 patients in the cryoballoon group and in 143 in the radiofrequency group (1-year Kaplan-Meier event rate estimates, 34.6% and 35.9%, respectively; hazard ratio, 0.96; 95% confidence interval CI, 0.76 to 1.22; P<0.001 for noninferiority). The primary safety end point occurred in 40 patients in the cryoballoon group and in 51 patients in the radiofrequency group (1-year Kaplan-Meier event rate estimates, 10.2% and 12.8%, respectively; hazard ratio, 0.78; 95% CI, 0.52 to 1.18; P=0.24).
In this randomized trial, cryoballoon ablation was noninferior to radiofrequency ablation with respect to efficacy for the treatment of patients with drug-refractory paroxysmal atrial fibrillation, and there was no significant difference between the two methods with regard to overall safety. (Funded by Medtronic; FIRE AND ICE ClinicalTrials.gov number, NCT01490814.).
Real‐Time Contact Force Sensing for Pulmonary Vein Isolation
Introduction
The additional benefit of contact force (CF) technology during pulmonary vein isolation (PVI) for paroxysmal atrial ...fibrillation (AF) to improve mid‐term clinical outcome is unclear.
Methods and Results
Eligible patients with symptomatic paroxysmal AF were enrolled in this prospective trial, comparing circular antral catheter ablation (guided by Carto 3 System, Biosense Webster) using either a new open‐irrigated CF catheter (SmartTouch Thermocool, Biosense Webster) (CF group) or a non‐CF open‐irrigated catheter (EZ Steer Thermocool, Biosense Webster) (control group). Overall, 30 patients were enrolled in each group, with a standardized 12‐month follow‐up, free of antiarrhythmic therapy. Demographic, cardiovascular and anatomic characteristics were similar in both groups. Though complete PVI was eventually achieved in all cases in both groups, success using an exclusive anatomic approach was 80.0% in CF group versus 36.7% in control group (P < 0.0001). CF use was associated with significant reductions in fluoroscopy exposure (P < 0.01) and radiofrequency time (P = 0.01). The incidence rates of AF recurrence were 10.5% (95% CI, 1.38–22.4) in the CF group, and 35.9% (95% CI, 12.4–59.4) in the control group (log rank test, P = 0.04). After adjustment on potential confounders, the use of CF catheter was found to be associated with a lower AF recurrence (OR 0.18, 95% CI 0.04–0.94, P = 0.04).
Conclusion
Our findings suggest a potential benefit of real‐time CF sensing technology, in reducing AF recurrence during the first year after PVI.
Introduction
Pulmonary vein isolation (PVI) is effective at treating 50% of unselected patients with persistent atrial fibrillation (AF). Alternatively, PVI combined with a new ablation strategy ...entitled the Marshall‐PLAN ensures a 78% 1‐year sinus rhythm (SR) maintenance rate in the same population. However, a substantial subset of patients could undergo the Marshall‐PLAN unnecessarily. It is therefore essential to identify those patients who can be treated with PVI alone versus those who may truly benefit from the Marshall‐PLAN before ablation is performed. In this context, we hypothesized that electrical cardioversion (EC) could help to select the most appropriate strategy for each patient.
Methods
In this multicentre, prospective, randomized study, patients with AF recurrence within 4 weeks after EC will be randomized 1:1 to PVI alone or the Marshall‐PLAN. Conversely, patients in whom SR is maintained for ≥4 weeks after EC will be treated with PVI only and included in a prospective registry. The primary endpoint will be the 1‐year SR maintenance rate after a single ablation procedure.
Results and Conclusion
The Marshall‐PLAN might be necessary in patients with an advanced degree of persistent AF (i.e., where SR is not maintained for ≥4 uninterrupted weeks after EC). Conversely, in patients with mild or moderate persistent AF (i.e., where SR is maintained for ≥4 weeks after EC), PVI alone might be a sufficient ablation strategy. The PACIFIC trial is the first study designed to assess whether rhythm monitoring after EC could help to identify patients who should undergo adjunctive ablation strategies beyond PVI.
The primary safety and efficacy endpoints of the randomized FIRE AND ICE trial have recently demonstrated non-inferiority of cryoballoon vs. radiofrequency current (RFC) catheter ablation in patients ...with drug-refractory symptomatic paroxysmal atrial fibrillation (AF). The aim of the current study was to assess outcome parameters that are important for the daily clinical management of patients using key secondary analyses. Specifically, reinterventions, rehospitalizations, and quality-of-life were examined in this randomized trial of cryoballoon vs. RFC catheter ablation.
Patients (374 subjects in the cryoballoon group and 376 subjects in the RFC group) were evaluated in the modified intention-to-treat cohort. After the index ablation, log-rank testing over 1000 days of follow-up demonstrated that there were statistically significant differences in favour of cryoballoon ablation with respect to repeat ablations (11.8% cryoballoon vs. 17.6% RFC; P = 0.03), direct-current cardioversions (3.2% cryoballoon vs. 6.4% RFC; P = 0.04), all-cause rehospitalizations (32.6% cryoballoon vs. 41.5% RFC; P = 0.01), and cardiovascular rehospitalizations (23.8% cryoballoon vs. 35.9% RFC; P < 0.01). There were no statistical differences between groups in the quality-of-life surveys (both mental and physical) as measured by the Short Form-12 health survey and the EuroQol five-dimension questionnaire. There was an improvement in both mental and physical quality-of-life in all patients that began at 6 months after the index ablation and was maintained throughout the 30 months of follow-up.
Patients treated with cryoballoon as opposed to RFC ablation had significantly fewer repeat ablations, direct-current cardioversions, all-cause rehospitalizations, and cardiovascular rehospitalizations during follow-up. Both patient groups improved in quality-of-life scores after AF ablation.
ClinicalTrials.gov identifier: NCT01490814.
Cryoballoon ablation (Cryoballoon) has emerged as a new alternative for the treatment of symptomatic drug-refractory atrial fibrillation (AF). Whether the results of Cryoballoon are more reproducible ...than those of radiofrequency (RF) ablation remains to be proved.
A total of 860 consecutive patients undergoing a first ablation procedure for paroxysmal AF (467 treated with RF and 393 treated with Cryoballoon) were selected from a prospective multicentre survey of AF ablation (FrenchAF). Radiofrequency and Cryoballoon were compared regarding mid-term efficacy and safety. During a median follow-up of 14 months (interquartile range 8-23), patients treated with Cryoballoon displayed similar rates of freedom from atrial arrhythmia relapse in centres performing this technique (68-80% at 18 months). However, in centres performing RF, a greater heterogeneity in procedural results was observed (46-79% were free from atrial arrhythmia relapse at 18 months). On multivariate analysis, Cryoballoon (HR = 0.47, 95% CI 0.35-0.65, P < 0.001) and annual AF ablation caseload (HR = 0.87 per every 100 AF ablation procedures per year; 95% CI 0.80-0.96, P = 0.003) were independent predictors of procedural success. However, on sensitivity analysis, according to the ablation method, annual AF ablation caseload predicted only sinus rhythm maintenance in the subgroup of patients treated with RF. Analysis of interoperator results with Cryoballoon and RF confirmed lower reproducibility of RF, but suggested that besides caseload, other operator-related factors may play a role.
Cryoballoon seems to be less operator-dependent and more reproducible than RF in the setting of paroxysmal AF ablation.
Contact force (CF) is a major determinant of lesion size and transmurality and has the potential to improve efficacy of atrial fibrillation ablation. This study sought to evaluate the safety and ...effectiveness of a novel irrigated radiofrequency ablation catheter that measures real-time CF in the treatment of patients with paroxysmal atrial fibrillation.
A total of 300 patients with symptomatic, drug-refractory, paroxysmal atrial fibrillation were enrolled in a prospective, multicenter, randomized, controlled trial and randomized to radiofrequency ablation with either a novel CF-sensing catheter or a non-CF catheter (control). The primary effectiveness end point consisted of acute electrical isolation of all pulmonary veins and freedom from recurrent symptomatic atrial arrhythmia off all antiarrhythmic drugs at 12 months. The primary safety end point included device-related serious adverse events. End points were powered to show noninferiority. All pulmonary veins were isolated in both groups. Effectiveness was achieved in 67.8% and 69.4% of subjects in the CF and control arms, respectively (absolute difference, -1.6%; lower limit of 1-sided 95% confidence interval, -10.7%; P=0.0073 for noninferiority). When the CF arm was stratified into optimal CF (≥90% ablations with ≥10 g) and nonoptimal CF groups, effectiveness was achieved in 75.9% versus 58.1%, respectively (P=0.018). The primary safety end point occurred in 1.97% and 1.40% of CF patients and control subjects, respectively (absolute difference, 0.57%; upper limit of 1-sided 95% confidence interval, 3.61%; P=0.0004 for noninferiority).
The CF ablation catheter met the primary safety and effectiveness end points. Additionally, optimal CF was associated with improved effectiveness.
http://www.clinicaltrials.gov. Unique identifier: NCT01278953.
Type-2 diabetes mellitus (DM) is associated with an increased risk of atrial fibrillation (AF). It is unclear whether DM is a risk factor for arrhythmia recurrence following catheter ablation of AF. ...We performed a nonrandomised, observational study in 7 high-volume European centres. A total of 2,504 patients who underwent catheter ablation of AF were included, and procedural outcomes were compared among patients with or without DM. Patients with DM (234) accounted for 9.3% of the sample, and were significantly older, had a higher BMI and suffered more frequently from persistent AF. Arrhythmia relapses at 12 months after AF ablation occurred more frequently in the DM group (32.0% vs 25.3%, p = 0.031). After adjusting for type of AF (i.e., paroxysmal vs persistent), during a median follow-up of 17 ± 16 months, atrial arrhythmia free-survival was lower in the diabetics with persistent AF (log-rank p = 0.003), and comparable for paroxysmal AF (log-rank p = 0.554). These results were confirmed in a propensity-matched analysis, and DM was also an independent predictor of AF recurrence on the multivariate analysis (hazard ratio 1.39; 95% confidence interval 95%1.07 to 1.88; p = 0.016). There was no significant difference in the rate of periprocedural complications among DM and non-DM patients (3.8% vs 6.3%, p = 0.128). Efficacy and safety of cryoballoon ablation were comparable to radiofrequency ablation in both DM and no-DM groups. In conclusion, catheter ablation of AF appears to be safe in patients with DM. However, DM is associated with higher rate of atrial arrhythmia relapse, particularly for patients with persistent AF.
Introduction
The aim of this study was to evaluate a spatial correlation between active atrial fibrillation (AF) drivers measured by electrocardiographic imaging and complex fractionated atrial ...electrograms (CFAEs) in patients with persistent AF.
Methods
Sixteen patients with persistent AF were included. A biatrial geometry relative to an array of 252‐body‐surface‐electrodes was obtained from a noncontrast computed tomography scan. The reconstructed unipolar AF electrograms were signal‐processed (ECVUE™, CardioInsight Technologies Inc., Cleveland, OH, USA) to identify AF drivers. Before driver ablation, a biatrial mapping using the NavX system (St. Jude Medical, St. Paul, MN, USA) was performed to identify CFAEs. CFAE and driver regions were then quantified and compared.
Results
AF was terminated by driver ablation in 11/16 (70%) patients. The mean number of ablated driver regions was 4 ± 1 per patient. The most frequent driver locations were the inferior left atrium and coronary sinus, the right pulmonary veins, and the right atrium. In 49/63 (78%) of the driver locations, more than 75% of the driver site showed CFAEs. The mean ablated driver area was 58 ± 24 cm2 (19 ± 11% of total surface area). The mean CFAE area was 178 ± 59 cm2 (49 ± 16%). The percentage of non‐ablated CFAE area was 76 ± 13% of total CFAEs. In 9/11 patients with AF termination, the termination site showed CFAEs.
Conclusions
There is a significant overlap between AF driver regions identified by the ECVUE™ system and CFAE areas identified by the NavX system. AF driver regions are smaller and mostly embedded in larger CFAE areas. Selective ablation of drivers in CFAE areas seems sufficient to terminate persistent AF in the majority of patients.
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