Ablation Strategy For Persistent Atrial Fibrillation Research Articles

Abstract 4137964: Electrical Gaps and Outcomes After Redo AF Ablation: Comparative Analysis from the EARNEST-PVI Trial

Introduction: The efficacy of extensive ablation strategies in addition to pulmonary vein (PV) isolation is still controversial in persistent atrial fibrillation (AF) ablation. Gaps in previously ablated lesions can induce arrhythmias, potentially decreasing the effectiveness of extensive ablation. Purpose: To evaluate the incidence of gaps, gap-related reentry, and subsequent recurrence following redo AF ablation in the EARNEST-PVI trial (NCT03514693). Methods: The analysis was performed using the extended data of the EARNEST-PVI trial (N=512), a randomized controlled trial evaluating ablation strategies for persistent AF. Patients were randomized 1:1 to either the PVI-plus or PVI-alone group. During a median follow-up of 47 months, 126 (25%) patients underwent redo AF ablation. Among them, we enrolled patients who underwent PVI-alone (N=69), or PVI-plus left atrial (LA) linear ablations (LA roof and mitral isthmus) (N=46) during the index ablation. Results: In the previous PVI-alone group, electrical PV gaps were observed in 38 (57%) patients. In the previous PVI-plus group, 19 (41%), 10 (22%), and 11 (24%) patients had electrical gaps in the PVs, LA linear lines, or both, respectively. During the redo session, 19 atrial tachycardias (ATs) were observed/induced in 15 patients. ATs were more frequently observed in the PVI-plus group than in the PVI-alone group (23.9% vs. 5.8%, p=0.005). While 7 ATs were not associated with gaps, 2 were related to PV gaps, and 10 were related to gaps in the linear lesions. In the redo AF ablation, PVI was re-completed in all patients, and any induced ATs were eliminated by additional ablation. During a median follow-up of 32 months post-redo, patients with gaps had a lower clinical recurrence rate than those without (44.3 vs. 47.2%, log-rank p=0.033). However, the Cox regression analysis revealed that AF recurrence post-redo was associated only with PV gaps, and not with linear ablation gaps (hazard ratio, 0.57; 95% confidence interval, 0.32–0.99; p = 0.049). Conclusions: In redo AF ablations, electrical gaps were more prevalent in patients who underwent extensive ablation during the index procedure. While all gaps during redo were potentially arrhythmogenic, PV gaps alone were associated with AF recurrence after redo AF ablation.

Evaluation of the effectiveness and safety of a novel substrate-based radiofrequency ablation for persistent atrial fibrillation: a prospective, randomised, parallel-controlled, single-blinded study protocol

IntroductionPulmonary vein isolation (PVI) is the cornerstone of radiofrequency (RF) ablation for atrial fibrillation (AF). However, a single ablation strategy does not always achieve the desired therapeutic effect in all...

Abstract 11697: Combined-Energy Pulmonary Vein Isolation and Posterior Wall Isolation for Persistent Atrial Fibrillation: Results of a 3-year Follow-Up

Introduction: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation for paroxysmal atrial fibrillation (AF), but the optimal ablation strategy for persistent AF (PsAF) remains controversial. Hypothesis: The purpose of this study was to investigate whether combined-energy cryoballoon (CB) PVI and radiofrequency (RF) left atrial posterior wall isolation (LAPWI) at index ablation of PsAF yields higher success than PVI alone. Methods: Patients with persistent AF (n = 186) who underwent catheter ablation between 2016 and 2019 at a single large academic medical center were retrospectively reviewed. Patients with congenital heart disease or prior left atrial ablation or surgery were excluded. Combined-energy ablation (n=92) consisted of CB antral PVI followed by RF roof and floor lines to achieve LAPWI, along with isolation inside the box as needed. The control group had PVI only (n=94) with either CB (n=57) or RF (n=37). The primary endpoint was 12-, 24-, and 36-month freedom from any documented atrial tachyarrhythmia over 30 seconds after a 90-day blanking period following catheter ablation, compared by Kaplan-Meier analysis. Secondary endpoints included AF burden, procedural parameters, and complications. Results: The primary endpoint of 12-month freedom from any atrial tachyarrhythmia was higher for the combined-energy group vs the control group (79.1% vs 58.2%, p = 0.009). This improvement was sustained at 24 months (63.0% vs 45.8%) and at 36 months (60.3% vs 43.1%) and remained significant after adjustment for clinical covariates (adjusted HR 0.45, 95% confidence interval 0.22-0.95; p = 0.03). There was no significant difference in procedure time or complication rates, however fluoroscopy time was shorter with combined-energy ablation (p<.001). Conclusions: In this single center experience, combined-energy CB-PVI and RF-LAPWI was associated with reduced AF recurrence compared to PVI with a single energy source.

Multi-centre, prospective randomized comparison of three different substrate ablation strategies for persistent atrial fibrillation.

The optimal strategy for persistent atrial fibrillation (PerAF) is poorly defined. We conducted a multicentre, randomized, prospective trial to compare the outcomes of different ablation strategies for PerAF. We enrolled 450 patients and randomly assigned them in a 1:1:1 ratio to undergo pulmonary vein isolation and subsequently undergo the following three different ablation strategies: anatomical guided ablation (ANAT group, n = 150), electrogram guided ablation (EGM group, n = 150), and extensive electro-anatomical guided ablation (EXT group, n = 150). The primary endpoint was freedom from atrial fibrillation (AF) lasting longer than 30 s at 12 months after a single ablation procedure. After 12 months of follow-up, 72% (108) of patients in the EXT group were free from AF recurrence, as compared with the 64% (96) in the EGM group (P = 0.116), and 54% (81) in the ANAT group (P = 0.002). The EXT group showed less AF/atrial tachycardia recurrence than the EGM group (60% vs. 50%, P = 0.064) and the ANAT group (60% vs. 37.3%, P < 0.001). The EXT group showed the highest rate of AF termination (66.7%), followed by 56.7% in the EGM group, and 20.7% in the ANAT group. The AF termination signified less AF recurrence at 12 months compared to patients without AF termination (30.1% vs. 42.7%, P = 0.008). Safety endpoints did not differ significantly between the three groups (P = 0.924). Electro-anatomical guided ablation achieved the most favourable outcomes among the three ablation strategies. The AF termination is a reliable ablation endpoint.

Abstract 11177: Pulmonary Vein Reconnections Predict Good Clinical Outcomes After a Second Catheter Ablation of Persistent Atrial Fibrillation: Insight From the EARNEST-PVI Trial

Introduction: The effect of an extensive ablation strategy in addition to pulmonary vein (PV) isolation is still controversial in persistent atrial fibrillation (AF) ablation. Electrical PV reconnection is an important confounder affecting the trial results. Objectives: To evaluate the PV reconnection rate and association between the reconnection and AF recurrence after a re-do AF ablation in the EARNEST-PVI trial (NCT03514693). Methods: The analysis was performed using the extended data of the EARNEST-PVI trial (N=512), a randomized controlled trial to evaluate ablation strategies for persistent AF, which was conducted in the Osaka region of Japan. During a median follow-up of 47 months, a total of 126 (25%) patients underwent a re-do AF ablation. Among them, 120 (median age, 68 years; 36% female; 31% long-standing persistent AF, 95% contact force-sensing catheter use) whose follow-up data were available after the 2 nd AF ablation were enrolled in this study. Results: PV reconnections were observed in 75 (63%) patients. Although there was no difference in age, gender, long-standing persistent AF, and CA strategy during the index procedure, AF recurrence within 1 year was more frequent in patients with PV reconnections (81.3% vs. 64.4%, p = 0.039). During a median follow-up of 31 months after the re-do AF ablation, patients with PV reconnections had a lower clinical recurrence rate than those without (38.7 vs. 44.4%, log-rank p = 0.047). However, additional linear ablation did not affect the recurrence rate. Even after adjustment for age, gender, long-standing persistent AF, and presence of non-PV triggers, Cox regression analysis revealed that a number of reconnected PVs of ≥2 was independently associated with a lower recurrence of AF after the 2 nd AF ablation (hazard ratio, 0.36; 95% confidence interval, 0.19-0.67; p = 0.001). Conclusions: Among patients who underwent a redo-AF ablation in the EARNEST-PVI trial, about two-thirds exhibited PV reconnections. Patients with ≥2 PV reconnections had better clinical outcomes than those with ≤1 PV reconnections. A durable PV isolation is an important pre-requisite before exploring any additional ablation strategies for persistent AF.

Comparing the efficacy of catheter ablation strategies for persistent atrial fibrillation: a Bayesian analysis of randomized controlled trials.

Catheter ablation has been recommended as the first-line treatment option for selected patients with atrial fibrillation (AF). However, a widely accepted ablation strategy for persistent AF (perAF) has not yet been established. The benefits of ablation strategies are not conclusive for perAF. There is an urgent need to systematically analyze the results of previous studies and rank these treatment strategies to guide clinical practice. Randomized controlled trials (RCTs) on ablation for perAF were included. The primary outcome was recurrence of atrial tachyarrhythmia (AT) after a single ablation procedure. A Bayesian random-effects network meta-analysis model was fitted. Twenty-three studies were included in the analysis. A total of 3394 patients and 22 ablation strategies were found in the involved studies. The ablation strategy of pulmonary vein isolation (PVI) + electrical box isolation of the left atrial posterior wall (PBOX) + non-PV trigger ablation (NPV) showed the best treatment effect in terms of the primary outcome. The individualized ablation strategies of mapping and ablation combined with PVI, such as PVI + rotors, PVI + dispersion areas, and PVI + low voltage zone (LVZ) also showed a better ablation effect in perAF. PVI ablation is a widely used strategy in perAF and is recognized as a cornerstone procedure for perAF. The PVI + PBOX + NPV strategy showed the highest rank in our analysis. Mapping and ablation strategies that could provide individualized substrate modification also showed a better rank in our analysis and are believed to be a promising direction for the treatment of perAF.

Abstract 16499: Hybrid Cryoballoon Pulmonary Vein Isolation and Radiofrequency Posterior Wall Isolation for Persistent Atrial Fibrillation

Introduction: Catheter ablation of persistent atrial fibrillation (AF) is associated with less successful outcomes compared to paroxysmal AF. The optimal ablation strategy for persistent AF is not well established. We report our center’s experience utilizing a hybrid ablation approach of cryoballoon (CB) pulmonary vein isolation (PVI) followed by radiofrequency (RF) left atrial posterior wall isolation (LAPWI). Methods: 134 patients with persistent AF who underwent catheter ablation between 2016 and 2019 at our center were retrospectively reviewed. Patients with congenital heart disease or prior left atrial ablation or surgery were excluded. Hybrid ablation (n=62) consisted of CB PVI followed by RF roof and floor lines resulting in LAPWI. The control group (n=72) had PVI ±LAPWI with either CB (n=38) or RF (n=34). Outcomes were monitored with office visits and 7-day Holter monitors at 3, 6, 12, and 24 months post-ablation. The primary endpoint was freedom from any documented atrial tachyarrhythmia over 30 seconds. Results: Concomitant atrial flutter ablation was performed in 19/62 (31%) and 5/72 (7%) of hybrid and control cases, respectively. There was no significant difference in procedure time, however fluoroscopy time was shorter with hybrid ablation compared to control (p&lt;.01). 18-month freedom from atrial tachyarrhythmias was 70.4% with hybrid ablation and 51.6% with PVI±LAPWI with a single energy source (p=.048). Among those with recurrence, mean AF burden was significantly lower with hybrid ablation (7%) than with a single-energy approach (60%). Conclusion: In this single center experience with multiple operators, hybrid CB-RF PVI and LAPWI reduced AF recurrence (incidence and burden) compared to PVI±LAPWI with a single energy source.

Left Atrial Appendage Electrical Isolation as a Target in Atrial Fibrillation.

Although the benefit of catheter ablation of the pulmonary veins is well established in paroxysmal atrial fibrillation (AF), the optimal ablation strategy for persistent AF is yet to be determined. Pulmonary vein isolation in persistent AF often results in AF recurrence and the success rate may be low even after multiple procedures. Recurrent AF risk may besecondary to non-pulmonary vein triggers, and adjunctive therapies to better control persistent AF are under investigation. The left atrial appendage (LAA) is a complex structure with distinct physiological and electrical properties, and multiple studies have implicated the LAA as a potential contributor to persistence of AF. Therapies targeting the LAA for electrical isolation have demonstrated potential efficacy in freedom from AF. The overarching concept of this therapy is to isolate the atria electrically from the LAA via catheter ablation, surgical excision or ligation, or percutaneous ligation. LAA electrical isolation has already demonstrated benefit in reducing AF recurrence and AF burden. LAA electrical isolation has the potential to form a foundational piece in the optimal rhythm control management of AF and thereforewarrants further study and is the focus of this review.

Approaches to Catheter Ablation of Nonparoxysmal Atrial Fibrillation.

We describe the technical aspects and outcomes of several different ablation strategies for nonparoxysmal (persistent and long-standing persistent) atrial fibrillation (AF) and discuss our ablation strategy for these patients. Catheter ablation is an effective treatment strategy for patients with AF. Outcomes of ablation in patients with nonparoxysmal forms of AF tend to be worse than in patients with paroxysmal AF. Several recent studies have examined the long-term ablation success rates of different ablation approaches in patients with nonparoxysmal AF. While observational studies have suggested benefit of several different ablation strategies for persistent AF, large randomized controlled studies have shown similar success rates with pulmonary vein isolation (PVI) alone as compared versus PVI plus additional ablation. The optimal ablation strategy to achieve long-term freedom from recurrent arrhythmias in patients with nonparoxysmal AF remains controversial. Achieving durable PVI should be the cornerstone of AF ablation. Additional large-scale randomized controlled studies are necessary to determine whether additional ablation might result in improved long-term ablation success rates in these patients.

Strategy and Outcome of Catheter Ablation for Persistent Atrial Fibrillation - Impact of Progress in the Mapping and Ablation Technologies.

Pulmonary vein (PV) antrum isolation (PVAI) is effective in treating paroxysmal atrial fibrillation (AF) but is less so for persistent AF. A recent randomized study on the ablation strategies for persistent AF demonstrated that 2 common atrial substrate modifications, creation of linear lesions in the left atrium and ablation of complex fractionated electrogram sites, in addition to PVAI did not improve the outcome compared with stand-alone PVAI, suggesting the necessity of a more individualized, selective approach to persistent AF. There are emerging technologies, including high-resolution mapping with the use of multi-electrode catheter and auto mapping system and contact force (CF) guide ablation; the former allows rapid and accurate confirmation of the completeness of PVAI, and the latter enhances the achievement of durable ablation lesions more securely. Ablation for fibrotic area(s) has been proposed as a new approach for substrate modification, and high-resolution mapping is useful to define the area with low-voltage electrograms, a surrogate marker for atrial fibrosis. Ablation for non-PV triggers in addition to PVAI improves the outcome of persistent AF. Further, durable isolation of the left atrial posterior wall may reduce AF recurrence. These ablation strategies with concomitant use of the emerging technologies are strongly expected to enhance the effectiveness of catheter ablation for persistent AF.

Unanswered Questions in Complex Fractionated Atrial Electrogram Ablation.

Pulmonary vein isolation has been accepted as potential target for ablation of paroxysmal atrial fibrillation (AF) given that the pulmonary veins are the main source of AF triggers. However, ablation strategies for persistent AF are less well defined. Mapping and ablation of complex fractionated atrial electrograms (CFAEs) is one strategy that has been proposed as a strategy for substrate modification although there is no consensus on their definition and procedural end points. Results of clinical studies have been conflicting. In this review, we aimed to discuss yesterday, today, and tomorrow of CFAEs ablation in persistent AF ablation.