Durability of posterior wall isolation after catheter ablation among patients with recurrent atrial fibrillation

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

Left atrial posterior wall isolation using pulsed-field ablation: procedural characteristics, safety, and mid-term outcomes

BACKGROUND

Non-pulmonary vein (PV) ablation targets such as posterior wall isolation (PWI) have been tested in patients with persistent atrial fibrillation (AF). Pulsed-field ablation (PFA) offers a novel ablation technology possibly able to overcome the obstacles of incomplete PWI and concerns of damage to adjacent structures compared to thermal energy sources. Our aim was to assess procedural characteristics, safety, and mid-term outcomes of patients undergoing PWI using PFA in a clinical setting.

METHODS

Patients undergoing PFA-PVI with PWI were included. First-pass isolation was controlled using a multipolar mapping catheter.

RESULTS

One hundred consecutive patients were included (median age 69 [IQR 63-75] years, 33 females (33%), left atrial size 43 [IQR 39-47] mm, paroxysmal AF 24%). Median procedure time was 66 (IQR 59-77) min, and fluoroscopy time was 11 (8-14) min. PWI using PFA was achieved in 100% of patients with a median of 19 applications (IQR 14-26). There were no major complications. Overall, in 15 patients (15%), recurrent AF/AT was noted during a median follow-up of 144 (94-279) days.

CONCLUSIONS

PWI using PFA appears safe and results in high acute isolation rates and high arrhythmia survival during mid-term follow-up. Further randomized trials are essential and warranted.

Safety and effectiveness of additional left atrial posterior wall ablation using pulsed field ablation for persistent and long-standing persistent atrial fibrillation patients

INTRODUCTION

The unique safety profile of pulsed field ablation (PFA) has made pulmonary vein isolation (PVI) + left atrial posterior wall (LAPW) ablation promising for treating persistent atrial fibrillation (PerAF). The goal of this study was to assess long-term freedom from atrial fibrillation, atrial flutter, and atrial tachycardia (AF/AFL/AT), as well as the safety and feasibility of LAPW PFA using multipolar, pentaspline Farawave catheter.

METHODS

Retrospective observational study at a single institution. Data for 94 patients were collected from a prespecified intraprocedural registry. The long-term AF/AFL/AT recurrence assessment was based on an analysis of medical history; 24-h Holter ECGs at 3, 6, and 12 months postablation; and 12-lead ECGs recorded during symptomatic episodes or visits.

RESULTS

Half of the patients had ls-PerAF, and half had a history of catheter ablation-mostly RF PVI. The acute ablation success rate was 100%, and the primary safety outcome was observed in 2 patients. Fifty patients experienced AF/AFL/AT recurrence (54.3%). An increase in LAPW low-voltage areas and AF classification were associated with arrhythmia recurrence. After a median follow-up of 13 months, the Kaplan‒Meier estimated median time free of AF/AFL/AT after a single procedure was 14.7 months.

CONCLUSION

PFA PVI + PWA had the best outcome in perAF patients without extensive LA fibrosis. AF recurrence was paroxysmal in significant part of the cohort. The addition of PWA to PVI using multipolar PFA was safe and did not significantly influence the transpired ablation time.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

High-frequency low-tidal volume ventilation improves procedural and long-term clinical outcomes in persistent atrial fibrillation ablation: Prospective multicenter registry

BACKGROUND

High-frequency, low-tidal volume (HFLTV) ventilation increases the efficacy and efficiency of radiofrequency catheter ablation (RFCA) of paroxysmal atrial fibrillation. Whether those benefits can be extrapolated to RFCA of persistent atrial fibrillation (PeAF) is undetermined.

OBJECTIVE

The purpose of this study was to evaluate whether using HFLTV ventilation during RFCA in patients with PeAF is associated with improved procedural and long-term clinical outcomes compared to standard ventilation (SV).

METHODS

In this prospective multicenter registry (REAL-AF), patients who had undergone pulmonary vein isolation (PVI) + posterior wall isolation (PWI) for PeAF using either HFLTV ventilation or SV were included. The primary efficacy outcome was freedom from all-atrial arrhythmias at 12 months. Secondary outcomes included procedural and long-term clinical outcomes and complications.

RESULTS

A total of 210 patients were included (HFLTV=95 vs. SV=115) in the analysis. There were no differences in baseline characteristics between the groups. Procedural time (80 [66-103.5] minutes vs 110 [85-141] minutes; P <.001), total radiofrequency (RF) time (18.73 [13.93-26.53] minutes vs 26.15 [20.30-35.25] minutes; P <.001), and pulmonary vein RF time (11.35 [8.78-16.69] minutes vs 18 [13.74-24.14] minutes; P <.001) were significantly shorter using HFLTV ventilation compared with SV. Freedom from all-atrial arrhythmias was significantly higher with HFLTV ventilation compared with SV (82.1% vs 68.7%; hazard ratio 0.41; 95% confidence interval [0.21-0.82]; P = .012), indicating a 43% relative risk reduction and a 13.4% absolute risk reduction in all-atrial arrhythmia recurrence. There was no difference in long-term procedure-related complications between the groups (HFLTV 1.1% vs SV 0%, P = .270).

CONCLUSION

In patients undergoing RFCA with PVI + PWI for PeAF, the use of HFLTV ventilation was associated with higher freedom from all-atrial arrhythmias at 12-month follow-up, with significantly shorter procedural and RF times compared to SV, while reporting a similar safety profile.

Incidence, distribution, and electrogram characteristics of endocardial-epicardial connections identified by ultra-high-resolution mapping during a left atrial posterior wall isolation of atrial fibrillation

PURPOSE

The left atrial posterior wall (LAPW) can be a target for atrial fibrillation (AF) catheter ablation but is sometimes difficult to completely isolate due to the presence of endocardial-epicardial connections. We aimed to investigate the incidence and distribution of epicardial residual connections (epi-RCs) and the electrogram characteristics at epi-RC sites during an initial LAPW isolation.

METHODS

We retrospectively studied 102 AF patients who underwent LAPW mapping before and after a first-pass linear ablation along the superior and inferior LAPW (pre-ablation and post-ablation maps) using an ultra-high-resolution mapping system (Rhythmia, Boston Scientific).

RESULTS

Epi-RCs were observed in 41 patients (40.2%) and were widely distributed in the middle LAPW area and surrounding it. The sites with epi-RCs had a higher bipolar voltage amplitude and greater number of fractionated components than those without (median, 1.09 mV vs. 0.83 mV and 3.9 vs. 3.4 on the pre-ablation map and 0.38 mV vs. 0.27 mV and 8.5 vs. 4.2 on the post-ablation map, respectively; P < 0.001). Receiver operating characteristic analyses demonstrated that the number of fractionated components on the post-ablation map had a larger area under the curve of 0.847 than the others, and the sensitivity and specificity for predicting epi-RCs were 95.4% and 62.1%, respectively, at an optimal cutoff of 5.0.

CONCLUSIONS

Among the patients with epi-RCs after a first-pass LAPW linear ablation, areas with a greater number of fractionated components (> 5.0 on the post-ablation LAPW map) may have endocardial-epicardial connections and may be potential targets for touch-up ablation to eliminate the epi-RCs.

Pulsed field ablation technology for pulmonary vein and left atrial posterior wall isolation in patients with persistent atrial fibrillation

INTRODUCTION

Limited data exist on pulsed-field ablation (PFA) in patients with persistent atrial fibrillation (PeAF) undergoing left atrial posterior wall isolation (LAPWI).

METHODS

The Advanced TecHnologies For SuccEssful AblatioN of AF in Clinical Practice (ATHENA) prospective registry included consecutive patients referred for PeAF catheter ablation at 9 Italian centers, treated with the FARAPULSETM-PFA system. The primary efficacy and safety study endpoints were the acute LAPWI rate, freedom from arrhythmic recurrences and the incidence of major periprocedural complications. Patients undergoing pulmonary vein isolation (PVI) alone, PWI + LAPWI and redo procedures were compared.

RESULTS

Among 249 patients, 21.7% had long-standing PeAF, 79.5% were male; mean age was 63 ± 9 years. LAPWI was performed in 57.6% of cases, with 15.3% being redo procedures. Median skin-to-skin times (PVI-only 68 [60-90] vs. PVI + LAPWI 70 [59-88] mins) did not differ between groups. 45.8% LAPWI cases were approached with a 3D-mapping system, and 37.3% with intracardiac echocardiography. LAPWI was achieved in all patients by means of PFA alone, in 88.8% cases at first pass. LAPWI was validated either by an Ultrahigh-density mapping system or by recording electrical activity + pacing maneuvers. No major complications occurred, while 2.4% minor complications were detected. During a median follow-up of 273 [191-379] days, 41 patients (16.5%) experienced an arrhythmic recurrence after the 90-day blanking period, with a mean time to recurrence of 223 ± 100 days and no differences among ablation strategies.

CONCLUSION

LAPWI with PFA demonstrates feasibility, rapidity, and safety in real-world practice, offering a viable alternative for PeAF patients. LAPWI is achievable even with a fluoroscopy-only method and does not significantly extend overall procedural times.

Repeat catheter ablation for atrial fibrillation

Catheter ablation of atrial fibrillation (AF) is an established therapy that reduces AF burden, improves quality of life, and reduces the risks of cardiovascular outcomes. Although there are clear guidelines for the application of de novo catheter ablation, there is less evidence to guide recommendations for repeat catheter ablation in patients who experience recurrent AF. In this review, we examine the rationale for repeat ablation, mechanisms of recurrence, patient selection, optimal timing, and procedural strategies. We discuss additional important considerations, including treatment of comorbidities and risk factors, risk of complications, and effectiveness. Mechanisms of recurrent AF are often due to non-pulmonary vein (non-PV) triggers; however, there is insufficient evidence supporting the routine use of empiric lesion sets during repeat ablation. The emergence of pulsed field ablation may alter the safety and effectiveness of de novo and repeat ablation. Extrapolation of data from randomized trials of de novo ablation does not optimally inform efficacy in cases of redo ablation. Additional large, randomized controlled trials are needed to address important clinical questions regarding procedural strategies and timing of repeat ablation.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Posterior wall isolation via a multi-electrode radiofrequency balloon catheter: feasibility, technical considerations, endoscopic findings and comparison with cryoballoon technologies

BACKGROUND

Posterior wall (PW) isolation is an important adjunctive ablation target in patients with non-paroxysmal atrial fibrillation (AF). Traditionally performed with point-by-point radiofrequency (RF) ablation, PW isolation has also been performed with different cryoballoon technologies. We aimed at assessing the feasibility of PW isolation with the novel RF balloon catheter Heliostar™ (Biosense Webster, CA, USA).

METHODS

We prospectively enrolled 32 consecutive patients with persistent AF scheduled for first-time ablation with the Heliostar™ device. Procedural data were compared with those from 96 consecutive persistent AF patients undergoing pulmonary vein (PV) plus PW isolation with a cryoballoon device. The ratio RF balloon/cryoballoon was 1:3 for each operator involved in the study, aiming at avoiding any imbalance related to different experience.

RESULTS

Single-shot PV isolation was documented in a significantly higher number of cases with the RF balloon technology compared to cryoballoon ablation (89.8% vs. 81.0%; p = 0.02, respectively). PW isolation was achieved with a similar number of balloon applications between the two groups (11 ± 4 with the RF balloon versus 11 ± 2 with the cryoballoon; p = 0.16), but in a significantly shorter time among RF balloon patients (228 ± 72 s versus 1274 ± 277 s with cryoballoon; p < 0.001). Primary safety endpoint occurred in none of the RF balloon patients versus 5 (5.2%) patients in the cryoballoon group (p = 0.33). Primary efficacy endpoint was achieved in all (100%) RF balloon patients versus 93 (96.9%) cryoballoon ones (p = 0.57). Oesophageal endoscopy did not show any signs of thermal lesions in RF balloon patients with luminal temperature rise.

CONCLUSIONS

RF balloon-based PW isolation was safe and promoted shorter procedure times compared to similar cryoballoon-based ablation procedures.

Safety and Effectiveness of Adjunctive Posterior Wall Isolation in Atrial Fibrillation Patients: An Updated Meta-Analysis

As the atrial fibrillation (AF) recurrence rate remains high after pulmonary vein isolation (PVI), additional left atrial posterior wall isolation (PWI) has been studied in randomized controlled trials, however, the results are conflicting. We performed an updated meta-analysis by searching online databases for the randomized controlled trials comparing the PWI + PVI group to the PVI alone group in patients with AF. The outcomes of interest were AF recurrence, all atrial arrhythmia recurrence, and atrial flutter/atrial tachycardia (AT) recurrence. Risk ratio (RR) with a 95% confidence interval (CI) was estimated using a random effects model. A total of 1,612 patients, with 807 in the PWI + PVI group and 805 in the PVI alone group were included. The mean age was 60 (9) years, 75% were men and 71% had persistent AF. The PWI + PVI group had lower AF recurrence as compared with the PVI alone group (25% vs 32%, RR 0.73, 95% CI 0.56 to 0.96, p = 0.02). There were no significant differences in all atrial arrhythmia recurrence (RR 0.90, 95% CI 0.78 to 1.04, p = 0.16), atrial flutter/AT recurrence (RR 1.19, 95% CI 0.92 to 1.55, p = 0.19) or adverse event rates in the 2 groups (36 vs 31; RR 1.09, 95% CI 0.67 to 1.77, p = 0.73). In conclusion, adjunctive PWI in addition to PVI can be achieved with lower AF recurrence but with a nonsignificant increase in atrial flutter/AT recurrence, resulting in an overall similar rate of all atrial arrhythmia recurrence without increasing the risk of adverse events, when compared with PVI alone strategy.

High-Frequency Low-Tidal Volume Ventilation Improves Long-Term Outcomes in AF Ablation: A Multicenter Prospective Study

BACKGROUND

High-frequency, low-tidal-volume (HFLTV) ventilation is a safe and simple strategy to improve catheter stability and first-pass isolation during pulmonary vein (PV) isolation. However, the impact of this technique on long-term clinical outcomes has not been determined.

OBJECTIVES

This study sought to assess acute and long-term outcomes of HFLTV ventilation compared with standard ventilation (SV) during radiofrequency (RF) ablation of paroxysmal atrial fibrillation (PAF).

METHODS

In this prospective multicenter registry (REAL-AF), patients undergoing PAF ablation using either HFLTV or SV were included. The primary outcome was freedom from all-atrial arrhythmia at 12 months. Secondary outcomes included procedural characteristics, AF-related symptoms, and hospitalizations at 12 months.

RESULTS

A total of 661 patients were included. Compared with those in the SV group, patients in the HFLTV group had shorter procedural (66 [IQR: 51-88] minutes vs 80 [IQR: 61-110] minutes; P < 0.001), total RF (13.5 [IQR: 10-19] minutes vs 19.9 [IQR: 14.7-26.9] minutes; P < 0.001), and PV RF (11.1 [IQR: 8.8-14] minutes vs 15.3 [IQR: 12.4-20.4] minutes; P < 0.001) times. First-pass PV isolation was higher in the HFLTV group (66.6% vs 63.8%; P = 0.036). At 12 months, 185 of 216 (85.6%) in the HFLTV group were free from all-atrial arrhythmia, compared with 353 of 445 (79.3%) patients in the SV group (P = 0.041). HLTV was associated with a 6.3% absolute reduction in all-atrial arrhythmia recurrence, lower rate of AF-related symptoms (12.5% vs 18.9%; P = 0.046), and hospitalizations (1.4% vs 4.7%; P = 0.043). There was no significant difference in the rate of complications.

CONCLUSIONS

HFLTV ventilation during catheter ablation of PAF improved freedom from all-atrial arrhythmia recurrence, AF-related symptoms, and AF-related hospitalizations with shorter procedural times.

Efficacy and safety of hybrid epicardial and endocardial ablation versus endocardial ablation in patients with persistent and longstanding persistent atrial fibrillation: a randomised, controlled trial

Background

Endocardial catheter ablation (CA) has limited long-term benefit for persistent and longstanding persistent atrial fibrillation (PersAF/LSPAF). We hypothesized hybrid epicardial-endocardial ablation (HA) would have superior effectiveness compared to CA, including repeat (rCA), in PersAF/LSPAF.

Methods

CEASE-AF (NCT02695277) is a prospective, multi-center, randomized controlled trial. Nine hospitals in Poland, Czech Republic, Germany, United Kingdom, and the Netherlands enrolled eligible participants with symptomatic, drug refractory PersAF and left atrial diameter (LAD) > 4.0 cm or LSPAF. Randomization was 2:1 to HA or CA by an independent statistician and stratified by site. Treatment assignments were masked to the core rhythm monitoring laboratory. For HA, pulmonary veins (PV) and left posterior atrial wall were isolated with thoracoscopic epicardial ablation including left atrial appendage exclusion. Endocardial touch-up ablation was performed 91-180 days post-index procedure. For CA, endocardial PV isolation and optional substrate ablation were performed. rCA was permitted between days 91-180. Primary effectiveness was freedom from AF/atrial flutter/atrial tachycardia >30-s through 12-months absent class I/III anti-arrhythmic drugs except those not exceeding previously failed doses. It was assessed in the modified intention-to-treat (mITT) population who had the index procedure and follow-up data. Major complications were assessed in the ITT population who had the index procedure. Thirty-six month follow-up continues.

Findings

Enrollment began November 20, 2015 and ended May 22, 2020. In 154 ITT patients (102 HA; 52 CA), 75% were male, mean age was 60.7 ± 7.9 years, mean LAD was 4.7 ± 0.4 cm, and 81% had PersAF. Primary effectiveness was 71.6% (68/95) in HA versus 39.2% (20/51) in CA (absolute benefit increase: 32.4% [95% CI 14.3%-48.0%], p < 0.001). Major complications through 30-days after index procedures plus 30-days after second stage/rCA were similar (HA: 7.8% [8/102] versus CA: 5.8% [3/52], p = 0.75).

Interpretation

HA had superior effectiveness compared to CA/rCA in PersAF/LSPAF without significant procedural risk increase.

Funding

AtriCure, Inc.

Outcomes of adjunct posterior wall isolation in atrial fibrillation patients with cardiac implantable electronic devices

BACKGROUND

Although pulmonary vein isolation (PVI) remains the cornerstone of catheter ablation of atrial fibrillation (AF), several studies have illustrated clinical benefits associated with PVI with posterior wall isolation (PWI).

METHODS

This retrospective study investigated the outcomes of PVI alone versus PVI+PWI performed using the cryoballoon in patients with cardiac implantable electronic devices (CIEDs) and paroxysmal AF (PAF) or persistent AF (PersAF).

RESULTS

Acute PVI was achieved in all patients using cryoballoon ablation. Compared to PVI alone, PVI+PWI was associated with longer cryoablation, fluoroscopy, and total procedure times. Adjunct radiofrequency was required to complete PWI in 29/77 patients (37.7%). Adverse events were similar with PVI alone versus PVI+PWI. But at 24 ± 7 months of follow-up, not only cryoballoon PVI+PWI was associated with improved freedom from recurrent AF (74.3% vs. 46.0%, P = .007) and all atrial tachyarrhythmias (71.4% vs. 38.1%, P = .001) in patients with PersAF, cryoballoon PVI+PWI also yielded greater freedom from AF (88.1% vs. 63.7%, P = .003) and all atrial tachyarrhythmias (83.3% vs. 60.8%, P = .008) in those with PAF. Additionally, PVI+PWI was associated with higher reductions in atrial tachyarrhythmia burden (97.9% vs. 91.6%, P < .001), need for cardioversion (5.2% vs. 23.6%, P < .001) and repeat catheter ablation (10.4% vs. 26.1%, P = .005), and a longer time-to-arrhythmia recurrence (16 ± 6 months vs. 8 ± 5 months, P < .001) in both PersAF and PAF patients.

CONCLUSION

In CIED patients with PersAF or PAF, cryoballoon PVI+PWI is associated with a greater freedom from recurrent AF and atrial tachyarrhythmias, as compared to PVI alone during long-term follow-up.

Hybrid epicardial-endocardial ablation for long-standing persistent atrial fibrillation: A subanalysis of the CONVERGE Trial

Background

Favorable clinical outcomes are difficult to achieve in long-standing persistent atrial fibrillation (LSPAF) with catheter ablation (CA). The CONVERGE (Convergence of Epicardial and Endocardial Ablation for the Treatment of Symptomatic Persistent Atrial FIbrillation) trial evaluated the effectiveness of hybrid convergent (HC) ablation vs endocardial CA.

Objective

The study sought to evaluate the safety and effectiveness of HC vs CA in the LSPAF subgroup from the CONVERGE trial.

Methods

The CONVERGE trial was a prospective, multicenter, randomized trial that enrolled 153 patients at 27 sites. A post hoc analysis was performed on LSPAF patients. The primary effectiveness was freedom from atrial arrhythmias off new or increased dose of previously failed or intolerant antiarrhythmic drugs (AADs) through 12 months. The primary safety endpoint was major adverse event incidence through 30 days with HC. Key secondary effectiveness measures included (1) percent of patients achieving ≥90% AF burden reduction vs baseline and (2) AF freedom.

Results

Sixty-five patients (42.5% of total enrollment) had LSPAF; 38 in HC and 27 in CA. Primary effectiveness was 65.8% (95% confidence interval [CI] 50.7%-80.9%) with HC vs 37.0% (95% CI 5.1%-52.4%) with CA (P = .022). Through 18 months, these rates were 60.5% (95% CI 50.0%-76.1%) with HC vs 25.9% (95% CI 9.4%-42.5%) with CA (P = .006). Secondary effectiveness rates were higher than CA with HC at 12 and 18 months. Freedom from atrial arrhythmias off AADs was 52.6% (95% CI 36.8%-68.5%) and 47.4% (95% CI 31.5%-63.2%) with HC at 12 and 18 months vs 25.9% (95% CI 9.4%-42.5%) and 22.2% (95% CI 6.5%-37.9%) with CA, respectively (12 months: P = .031; 18 months: P = .038). Three (7.9%) major adverse events occurred within 30 days of HC.

Conclusion

Post hoc analysis demonstrated effectiveness and acceptable safety of HC compared with CA in LSPAF.

Efficacy and Safety Ablation Index-Guided High-Energy Linear Ablation for Persistent Atrial Fibrillation: PVI Plus Linear Ablation of Mitral Isthmus and Posterior Box Isolation

BACKGROUND

For patients with persistent atrial fibrillation (AF), whether linear ablation should be performed remains controversial, and the efficacy and safety for ablation index (AI)-guided high-energy linear ablation of mitral isthmus (MI) and left atrial (LA) posterior box isolation is still unclear. The aims of this study were to assess the feasibility and clinical success rate of pulmonary veins isolation (PVI) combined with linear ablation of LA roof and posterior inferior (posterior wall isolation) and MI compare with the PVI-alone method in patients of persistent AF.

METHODS AND RESULTS

362 consecutive persistent AF patients were enrolled from two electrophysiology centers. A total of 200 cases were in PVI-plus group and 162 cases were in PVI-alone group. The PVI-alone group received wide circumferential isolation of both ipsilateral pulmonary veins. PVI combined with linear ablation of left atrial posterior wall isolation (LAPWI)and MI were performed in the PVI-plus group. The primary study end point was the first recurrence of an atrial arrhythmia. After 24 months, freedom from the primary endpoint was achieved in 73.5% of the patients in the PVI-plus group and 62.5% in the PVI-alone group (hazard ratio = 0.62, 95% confidence interval: 0.43-0.91, log rank p = 0.012). The procedure-related complication rates were 2.5% in PVI-plus group and 1.9% in PVI-alone group (p = 0.808).

CONCLUSION

In this study, the ablation strategy of ablation (PVI plus linear ablation of mitral isthmus and posterior box isolation) was feasible and safe for persistent AF patients. Compared with the PVI-alone method, it improved outcomes in patients with persistent AF.

Gaps after linear ablation of persistent atrial fibrillation (Marshall-PLAN): Clinical implication

BACKGROUND

Beyond pulmonary vein (PV) isolation, anatomic isthmus transection is an adjunctive strategy for persistent atrial fibrillation. Data on the durability of multiple lines of block remain scarce.

OBJECTIVE

The purpose of this study was to evaluate the impact of gaps within such a lesion set.

METHODS

We followed 291 consecutive patients who underwent (1) vein of Marshall ethanol infusion, (2) PV isolation, and (3) mitral, cavotricuspid, and dome isthmus transection. Dome transection relied on 2 distinct strategies over time: a single roof line with touch-ups applied in case of gap demonstrated by conventional maneuvers (first leg), and an alternative floor line if the roof line exhibited a gap during high-density mapping with careful electrogram reannotation (second leg).

RESULTS

Twelve-month sinus rhythm maintenance was 70% after 1 procedure and 94% after 1 or 2 procedures. Event-free survival after the first procedure was lower in case of residual gaps within the lesion set (log-rank, P = .004). Delayed gaps were found in 94% of a second procedure performed in the 69 patients relapsing despite a complete lesion set with PV gaps increasing the risk of recurrence of atrial fibrillation (67% vs 34%; P = .02) and anatomic isthmus gaps supporting a majority of atrial tachycardias (60%). Between the first leg and the second leg, a significant decrease was found in roof lines considered blocked during the first procedure (99% vs 78%; P < .001) and in delayed dome gaps observed during a second procedure (68% vs 43%; P = .05).

CONCLUSION

Gaps are arrhythmogenic and can be reduced by optimized ablation and assessment of lines of block. Closing these gaps improves sinus rhythm maintenance.

Efficacy of left atrial posterior wall isolation guided by lesion size prediction module for non-paroxysmal atrial fibrillation

AIMS

The efficacy of left atrial posterior wall isolation (PWI) is controversial. Lesion durability may be a major cause of arrhythmia recurrence. The use of the lesion size prediction module improves lesion durability. This study aimed to compare the clinical outcomes of pulmonary vein isolation (PVI) alone and PWI in addition to PVI (PVI + PWI) in patients with non-paroxysmal atrial fibrillation (AF) using a lesion size prediction module.

METHODS AND RESULTS

This study is a sub-analysis of the recently published prospective multicentre observational study called ALCOHOL-AF (association of alcohol consumption with outcome of catheter ablation of AF). In this sub-analysis, patients with non-paroxysmal AF in whom PVI alone or PVI + PWI was performed using the lesion size prediction module were included. Freedom from atrial tachyarrhythmia was compared between PVI alone and PVI + PWI groups using propensity score analyses. Of the 3474 patients registered in the ALCOHOL-AF study, 572 patients (age 65.6 ± 10.1 years, male 77.4%, longstanding persistent AF 25.5%) were included in this sub-analysis. We selected 212 patients treated with PVI alone and 212 treated with PVI + PWI using one-to-one propensity score matching. During the follow-up period, atrial tachyarrhythmia recurrence was documented in 92 (43.4%) and 50 (23.6%) patients in the PVI alone and PVI + PWI groups, respectively. Freedom from atrial tachyarrhythmia recurrence without anti-arrhythmic drugs after a single procedure was significantly higher in PVI + PWI than in PVI alone groups (hazard ratio: 0.452, 95% confidence interval: 0.308-0.664, P < 0.001).

CONCLUSION

In this hypothesis-generating study, lesion size prediction module-guided PVI + PWI was associated with better clinical outcomes than PVI alone in patients with persistent or longstanding persistent AF.

Impact of high frequency stimulation to confirm a complete box isolation in catheter ablation of non-paroxysmal atrial fibrillation

INTRODUCTION

Pulmonary vein (PV) isolation (PVI) including the left atrial posterior wall (LAPW) (Box-PVI) is proposed as an additional strategy for non-paroxysmal atrial fibrillation (NPAF), however, the efficacy remains controversial. The more reliable and durable the Box-PVI we can create, the better the rhythm outcomes might be than with a conventional PVI alone. This study focused on the potential exit conduction of the box lesion and investigated whether the conventional Box-PVI would be sufficient.

METHODS AND RESULTS

We enrolled 350 consecutive patients with NPAF that underwent a conventional encircling Box-PVI and examined whether latent exit conduction and dormant "exit" conduction independently remained on the LAPW and in the PVs using high frequency stimulation (HFS) and an adenosine triphosphate (ATP) injection. All electrograms inside the box lesion were eliminated in all cases, however, HFS inside the box propagated outward in 23 cases (6.6%) without any exit conduction by conventional burst stimulation, and 24 cases (6.9%) exhibited only dormant "exit" conduction of the LAPW. Additional ablation where positive HFSs were observed created a complete bidirectional Box-PVI in 43 (41.3%) of the cases without a first pass Box-PVI. The recurrence rates depended on the groups classified according to the HFS response.

CONCLUSION

HFS delivered with an ATP injection on the LAPW and in the PVs following a Box-PVI could not only elucidate true exit block but also identified possible incomplete lesions or connections outside the ablation line, whose elimination could achieve a complete Box-PVI leading to a better rhythm outcome.

Mapping Atrial Fibrillation After Surgical Therapy to Guide Endocardial Ablation

BACKGROUND

Surgical ablation for atrial fibrillation (AF) can be effective, yet has mixed results. It is unclear which endocardial lesions delivered as part of hybrid therapy' will best augment surgical lesion sets in individual patients. We addressed this question by systematically mapping AF endocardially after surgical ablation and relating findings to early recurrence, then performing tailored endocardial ablation as part of hybrid therapy.

METHODS

We studied 81 consecutive patients undergoing epicardial surgical ablation (stage 1 hybrid), of whom 64 proceeded to endocardial catheter mapping and ablation (stage 2). Stage 2 comprised high-density mapping of pulmonary vein (PV) or posterior wall (PW) reconnections, low-voltage zones (LVZs), and potential localized AF drivers. We related findings to postsurgical recurrence of AF.

RESULTS

Mapping at stage 2 revealed PW isolation reconnection in 59.4%, PV isolation reconnection in 28.1%, and LVZ in 42.2% of patients. Postsurgical recurrence of AF occurred in 36 patients (56.3%), particularly those with long-standing persistent AF (P=0.017), but had no relationship to reconnection of PVs (P=0.53) or PW isolation (P=0.75) when compared with those without postsurgical recurrence of AF. LVZs were more common in patients with postsurgical recurrence of AF (P=0.002), long-standing persistent AF (P=0.002), advanced age (P=0.03), and elevated CHA₂DS₂-VASc (P=0.046). AF mapping revealed 4.4±2.7 localized focal/rotational sites near and also remote from PV or PW reconnection. After ablation at patient-specific targets, arrhythmia freedom at 1 year was 81.0% including and 73.0% excluding previously ineffective antiarrhythmic medications.

CONCLUSIONS

After surgical ablation, AF may recur by several modes particularly related to localized mechanisms near low voltage zones, recovery of posterior wall or pulmonary vein isolation, or other sustaining mechanisms. LVZs are more common in patients at high clinical risk for recurrence. Patient-specific targeting of these mechanisms yields excellent long-term outcomes from hybrid ablation.

Adjunctive Left Atrial Posterior Wall Isolation in Treating Atrial Fibrillation: Insight From a Large Secondary Analysis

OBJECTIVES

This study evaluated the role of adjunctive left atrium posterior wall isolation (PWI) in preventing atrial fibrillation (AF) recurrence.

BACKGROUND

The left atrium posterior wall is an arrhythmogenic substrate that contributes to the development of AF.

METHODS

This was an updated pooled analysis that included clinical data regarding PWI plus pulmonary vein isolation (PVI) in treating AF. The primary outcome was recurrence of atrial tachyarrhythmias.

RESULTS

A total of 26 studies with 3,287 patients with AF (age 61.7 ± 10.8 years) were included. Mean follow-up was 15.2 ± 8.4 months. Procedural success to achieve PWI was 92.8%. In paroxysmal AF, adjunctive PWI did not reduce the recurrence of all atrial arrhythmias (P = 0.21) or AF (P = 0.37); however, in persistent AF, adjunctive PWI was associated with substantially lower recurrence of all atrial arrhythmias (risk ratio: 0.74; P < 0.001) and AF (risk ratio: 0.67; P = 0.01), particularly when randomized data were included. Subgroup analyses based on meta-regression demonstrated that patients with older age, a larger left atrial diameter, and persistent AF benefited more significantly from the adjunctive PWI. Adjunctive PWI using either radiofrequency or a cryoballoon reduced AF recurrence, whereas using radiofrequency seemed to be associated with higher recurrence rate of atrial tachycardias and/or atrial flutter. Non-BOX adjunctive PWI rather than BOX PWI was associated with significantly lower recurrence of AF. The incidence of procedural adverse events between the PVI+PWI (3.2%) and PVI (2.8%) groups was low and similar. PVI+PWI needed longer ablation and/or procedural time but had similar fluoroscopy time.

CONCLUSIONS

Adjunctive PWI can be achieved in most patients without compromising safety. Patients with persistent AF appear to benefit from this approach. The ablation technology and/or approach may affect the clinical outcome of PWI.

The Hybrid Convergent Procedure for Persistent and Long-Standing Persistent Atrial Fibrillation From an Electrophysiologist's Perspective

In atrial fibrillation (AF), the pulmonary veins (PV) are central to arrhythmogenicity and are targeted by PV isolation (PVI). As AF progresses, triggers become more prevalent in non-PV areas including the left atrial posterior wall (LAPW). Reported benefits of LAPW isolation in Cox-maze IV led to exploration of ablation strategies using endocardial catheters. However, no single approach to endocardial LAPW isolation exists. Relative success in comparison to PVI alone has been mixed. The hybrid convergent procedure was developed to combine minimally invasive surgical and electrophysiology techniques to accomplish effective PVI and LAPW isolation. Epicardial LAPW isolation is performed by a cardiothoracic surgeon followed by endocardial ablation by an electrophysiologist who ensures PVI completion and targets any remaining gaps. Safety and effectiveness of hybrid convergent was evaluated in the prospective, multi-center, randomized controlled trial, Convergence of Epicardial and Endocardial Ablation for the Treatment of Symptomatic Persistent AF (CONVERGE). CONVERGE compared the effectiveness of the hybrid convergent procedure to endocardial catheter ablation for treatment of drug-refractory persistent and longstanding persistent AF and demonstrated primary effectiveness of higher freedom from atrial arrhythmias absent new/increased dose previously failed/intolerant anti-arrhythmic drugs through 12 months compared to endocardial catheter ablation. Greater freedom from AF and proportion of patients experiencing ≥90% burden reduction with hybrid convergent ablation were seen through 18 months follow-up. Improved electrophysiology lab efficiency was demonstrated by the reduction in endocardial ablation time with addition of epicardial ablation. This multi-disciplinary heart team procedure may improve outcomes in difficult-to-treat patients with advanced AF. This article is protected by copyright. All rights reserved.

Continuous and discontinuous radiofrequency energy delivery on the atrial free wall: Lesion transmurality, width, and biophysical characteristics

Background

Although lesion transmurality is required for durable pulmonary vein isolation, excess ablation is associated with increased risk of complications.

Objective

We sought to understand the impact of interrupted radiofrequency (RF) delivery conditions on lesion characteristics in the atrial free wall.

Methods

Thirty-three (11 left atrial, 22 right atrial) RF ablation lesions were created in the atria of 6 swine using power control mode (25 W, target contact force 15 g) with 1 of 3 conditions: 15 seconds ablation (n = 8), 30 seconds ablation (n = 14), or 2 15-second ablations at the same site separated by a 2-minute interruption (15 seconds × 2) (n = 11).

Results

Thirty of 33 lesions were transmural. Rates of transmurality (P = .45) and endocardial lesion width (5.6 ± 1.2 mm, P = .70) were similar between conditions. Mean tissue thickness was 1.7 ± 0.8 mm for transmural lesions. Wide variability in bipolar electrogram attenuation was observed across and within conditions and there were no significant between-group differences. Although impedance reductions were numerically greater in the 30-second and 15-second × 2 conditions (-14.6 ± 6.6 ohms and -14.0 ± 4.4 ohms, respectively) compared to the 15-second condition (-10.3 ± 6.4 ohms), variability was large, and differences were not statistically significant (P = .243). Impedance changes after ablation were largely transient.

Conclusion

A single 15-second ablation at 25 W (target contact force of 15 g) with good stability produced similarly sized lesions compared to 30-second ablations and 2 15-second ablations at the same site in atrial free wall tissue. These data suggest over-ablation in the atria is common, larger-diameter lesions may require greater power, and many clinically available parameters of lesion size may be unreliable on the posterior wall.

Differences in the durability of left atrial posterior wall isolation based on the isolation process

PURPOSE

The best strategy for durable left atrial posterior wall isolation (PWI) after completion of pulmonary vein isolation (PVI) is not yet determined. This study aimed to examine the differences in the durability of PWI based on the isolation process and the predictors of the reconduction of PWI.

METHODS

Among the 221 patients (mean age, 65 ± 11 years) with consecutive non-paroxysmal atrial fibrillation (AF) who completed PVI and PWI, 50 patients undergoing repeat AF ablation were enrolled and divided into the following groups based on how PWI was achieved at the initial procedure: by only the first line on the roof and floor line (group A), by additional gap ablation to the first line or second liner ablation next to the first line (group B), and by adjunct ablation inside the PW revealing the earliest activation (group C).

RESULTS

Reconduction of PWI occurred in 24 of the 50 patients (48%). The durability of PWI in groups A, B, and C was 81% (17 of 21 patients), 75% (6 of 8 patients), and 14% (3 of 21 patients), respectively (p < 0.01). In a multivariate analysis, the ablation inside the PW for PWI was the independent predictor of the reconduction of PWI (p < 0.001).

CONCLUSION

PWI achieved by the ablation inside the PW resulted in a high rate of reconduction. It may be necessary to aim to achieve the PWI without ablating the inside of the PW to prevent reconduction.

Contact-Force Guided Posterior Wall Isolation as an Adjunctive Ablation Strategy for Persistent Atrial Fibrillation

Background

The efficacy of posterior wall isolation (PWI) on top of pulmonary vein isolation (PVI) in patients affected by persistent atrial fibrillation (AF) is still controversial and little is known about the impact of contact-force (CF) technology.

Objective

In this retrospective study, we present our experience with PWI using CF sensing catheters and its efficacy and safety as an adjunctive ablation strategy on top of PVI for management of patients with persistent and longstanding persistent AF.

Methods

A total of 73 consecutive patients (20.5% female) affected by persistent atrial fibrillation (10.9% long-standing) underwent PWI as an adjunctive therapy to PVI using CF sensing catheters. Outcomes were reported as incidence of atrial arrhythmic recurrences (ARs) lasting >30 seconds at follow up and in addition, in patients provided with insertable cardiac monitors (ICM), as burden of AF or atrial tachycardias (AT) at relevant time points.

Results

PWI was successfully achieved in 65 (89.0%) patients. Two (2.7%) minor vascular procedural complications were observed. At 1 and 2-year follow-up, ARs free survival was observed in 80.5% and 64.1% of patients, respectively with 75.3% of patients off antiarrhythmic drugs at the last follow-up. Ten patients underwent repeat ablations during the follow-up. At multivariate analysis, early ARs within 3 months after procedure, were associated with a two-fold increased risk of late ARs at follow-up. Among patients provided with ICM, PWI on top of PVI was able to reduce the mean AT/AF burden of more than 50% compared with pre-ablation time, reporting very low levels (≤ 5%) over 2 years.

Conclusions

In persistent atrial fibrillation, PWI on top of PVI using CF sensing catheters is safe and effective, providing great reduction of burden of ARs. Early ARs are associated with a greater risk of late recurrences.

Hybrid Convergent Procedure for the Treatment of Persistent and Long-standing Persistent Atrial Fibrillation

Recent advances have been made in AF treatment, including the role of early rhythm control and landmark clinical trials using ablation therapy. However, some treatment gaps remain, including the creation of durable lesions outside the pulmonary veins and effective treatment of longstanding persistent AF. A novel epicardial-endocardial ablation approach - the hybrid convergent procedure - was developed to combine surgical and catheter ablation techniques into a collaborative, multidisciplinary approach to managing AF. In this review, the authors discuss recently published data on hybrid convergent ablation, including results of the CONVERGE clinical trial, in the context of current challenges to treatment of persistent and long-standing persistent AF. The review also aims to provide perspective on outstanding questions and future directions in this area.

Persistent Atrial Fibrillation: The Role of Left Atrial Posterior Wall Isolation and Ablation Strategies

Atrial fibrillation (AF) is a global disease with rapidly rising incidence and prevalence. It is associated with a higher risk of stroke, dementia, cognitive decline, sudden and cardiovascular death, heart failure and impairment in quality of life. The disease is a major burden on the healthcare system. Paroxysmal AF is typically managed with medications or endocardial catheter ablation to good effect. However, a large proportion of patients with AF have persistent or long-standing persistent AF, which are more complex forms of the condition and thus more difficult to treat. This is in part due to the progressive electro-anatomical changes that occur with AF persistence and the spread of arrhythmogenic triggers and substrates outside of the pulmonary veins. The posterior wall of the left atrium is a common site for these changes and has become a target of ablation strategies to treat these more resistant forms of AF. In this review, we discuss the role of the posterior left atrial wall in persistent and long-standing persistent AF, the limitations of current endocardial-focused treatment strategies, and future perspectives on hybrid epicardial-endocardial approaches to posterior wall isolation or ablation.

The role of posterior wall isolation in catheter ablation of persistent atrial fibrillation

The left atrial posterior wall has many embryologic, anatomic, and electrophysiologic characteristics, that are important for the initiation and maintenance of persistent atrial fibrillation. The left atrial posterior wall is a potential target for ablation in patients with persistent atrial fibrillation, a population in whom pulmonary vein isolation alone has resulted in unsatisfactory recurrence rates. Published clinical studies report conflicting results on the safety and efficacy of posterior wall isolation. Emerging technologies including optimized use of radiofrequency ablation, pulse field ablation, and combined endocardial/epicardial ablation may optimize approaches to posterior wall isolation and reduce the risk of injury to nearby structures such as the esophagus. Critical evaluation of future and ongoing clinical studies of posterior wall isolation requires careful scrutiny of many characteristics, including intraprocedural definition of posterior wall isolation, concomitant extrapulmonary vein ablation, and study endpoints.

Marshall bundle elimination, Pulmonary vein isolation, and Line completion for ANatomical ablation of persistent atrial fibrillation (Marshall-PLAN): Prospective, single-center study

BACKGROUND

Beyond pulmonary vein isolation (PVI), the optimal ablation strategy for persistent atrial fibrillation (AF) remains poorly defined.

OBJECTIVE

The purpose of this study was to examine a novel comprehensive ablation strategy (Marshall bundle elimination, Pulmonary vein isolation, and Line completion for ANatomical ablation of persistent atrial fibrillation [Marshall-PLAN]) strictly based on anatomical considerations.

METHODS

Left atrial (LA) sites were sequentially targeted as follows: (1) coronary sinus and vein of Marshall (CS-VOM) musculature; (2) PVI; and (3) anatomical isthmuses (mitral, roof, and cavotricuspid isthmus [CTI]). The primary endpoint was 12-month freedom from AF/atrial tachycardia (AT).

RESULTS

Seventy-five consecutive patients were included (age 61 ± 9 years; 10 women; AF duration 9 ± 11 months; mean LA volume 197 ± 43 mL). VOM ethanol infusion was completed in 69 patients (92%). The full Marshall-PLAN lesion set (VOM, PVI, mitral, roof, and CTI with block) was successfully completed in 68 patients (91%). At 12 months, 54 of 75 patients (72%) were free from AF/AT after a single procedure (no antiarrhythmic drugs) in the overall cohort. In the subset of patients with a complete Marshall-PLAN lesion set (n = 68), the single procedure success rate was 79%. After 1 or 2 procedures, 67 of 75 patients (89%) remained free from AF/AT (no antiarrhythmic drugs). After 1 or 2 procedures, VOM ethanol infusion was complete in 72 of 75 patients (96%).

CONCLUSION

A novel ablation strategy that systematically targets anatomical atrial structures (VOM ethanol infusion, PVI, and prespecified linear lesions) is feasible, safe, and associated with a high rate of freedom from arrhythmia recurrence at 12 months in patients with persistent AF.

Hybrid Convergent Procedure for the Treatment of Persistent and Long-Standing Persistent Atrial Fibrillation

Background:

The limited effectiveness of endocardial catheter ablation (CA) for persistent and long-standing persistent atrial fibrillation (AF) treatment led to the development of a minimally invasive epicardial/endocardial ablation approach (Hybrid Convergent) to achieve a more comprehensive lesion set with durable transmural lesions. The multicenter randomized controlled CONVERGE trial (Convergence of Epicardial and Endocardial Ablation for the Treatment of Symptomatic Persistent AF) evaluated the safety of Hybrid Convergent and compared its effectiveness to CA for persistent and long-standing persistent AF treatment.

Methods:

One-hundred fifty-three patients were randomized 2:1 to Hybrid Convergent versus CA. Primary effectiveness was freedom from AF/atrial flutter/atrial tachycardia absent new/increased dosage of previously failed/intolerant class I/III antiarrhythmic drugs through 12 months. Primary safety was major adverse events through 30 days. CONVERGE permitted left atrium size up to 6 cm and imposed no limits on AF duration, making it the only ablation trial to substantially include long-standing persistent–AF, that is, 42% patients with long-standing persistent–AF.

Results:

Of 149 evaluable patients at 12 months, primary effectiveness was achieved in 67.7% (67/99) patients with Hybrid Convergent and 50.0% (25/50) with CA ( P =0.036) on/off previously failed antiarrhythmic drugs and in 53.5% (53/99) versus 32.0% (16/50; P =0.0128) respectively off antiarrhythmic drugs. At 18 months using 7-day Holter, 74.0% (53/72) Hybrid Convergent and 55% (23/42) CA patients experienced ≥90% AF burden reduction. A total of 2.9% (3/102) patients had primary safety events within 7 days, and 4.9% (5/102) between 8 and 30 days postprocedure. No deaths, cardiac perforations, or atrioesophageal fistulas occurred. All but one primary safety event resolved.

Conclusions:

The Hybrid Convergent procedure has superior effectiveness compared to the CA for the treatment of persistent and long-standing persistent atrial fibrillation.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01984346.