Phrenic nerve injury in atrial fibrillation ablation using balloon catheters: Incidence, characteristics, and clinical recovery course

Phrenic nerve injury after atrial fibrillation ablation: different recovery courses among cryoballoon, laser balloon, and radiofrequency ablation

BACKGROUND

Phrenic nerve injury (PNI) is one of the common complications in atrial fibrillation (AF) ablation, which often recovers spontaneously. However, the course of its recovery has not been examined fully, especially in regard to the different ablation methods. We sought to compare the recovery course of PNI in cryoballoon, laser balloon, and radiofrequency ablation.

METHODS

This multicenter retrospective study analyzed 355 patients who suffered from PNI during AF ablation. PNI occurred during cryoballoon ablation (CB group) and laser balloon ablation (LB group) for a pulmonary vein isolation in 288 and 20 patients, and radiofrequency ablation for a superior vena cava (SVC) isolation (RF-SVC group) in 47 patients, respectively RESULTS: There was a significant difference in the estimated probability of PNI recovery after the procedure between the methods (p = 0.01). PNI recovered significantly earlier in the CB group, especially within 24 h and 3 months post-procedure (the percentage of the recovery within 24 h and 3 months: 49.7% and 71.5% in the CB group, 15.0% and 22.2% in the LB group, and 23.4% and 41.9% in the RF-SVC group, respectively). Persistent PNI after 12 months was observed in only seven patients in the CB group, one in the LB group, and four in the RF-SVC group, respectively.

CONCLUSION

PNI rarely persists over 12 months after AF ablation; however, there is a difference in the timing of its recovery. PNI recovers quicker with cryoballoon ablation than with laser balloon ablation or radiofrequency ablation of the SVC.

Cryoballoon vs. laser balloon ablation for atrial fibrillation: a meta-analysis

Background

Cryoballoon ablation (CBA) and laser balloon ablation (LBA) are two innovative ways for the treatment of atrial fibrillation (AF). This study aimed to evaluate the efficacy and safety of cryoballoon ablation and laser balloon ablation in patients with AF.

Methods

We searched Pubmed, Embase, Ovid, Web of Science and other databases for comparative trials comparing CB and LB ablation in the treatment of AF, from establishment of database to August, 2023.

Results

A total of 13 studies and 3,582 patients were included (CBA, n = 2,308; LBA, n = 1,274). There was no difference between CBA and LBA in acute PVI rate per vein, 12-months recurrence rate of AF, 12-months recurrence rate of atrial arrhythmia, occurrence rate of pericardial tamponade, occurrence rate of inguinal complications. LBA presented a lower acute PVI rate per patients (CBA 97.0% vs. LBA 93.4%, RR = 1.04, 95%CI: 1.01-1.07). Transient nerve palsy was more likely to occur after CBA (CBA 2.7% vs. LBA 0.7%, RR = 4.25, 95%CI: 2.06-8.76). However, the occurrence of persistent nerve palsy between CBA and LBA groups were similar (CB 1.4% vs. LB 1.0%, RR = 1.09, 95%CI: 0.55-2.14). In terms of procedural duration, the procedural time of CBA was shorter than that of LBA (WMD = -26.58, 95%CI: -36.71-16.46).

Conclusions

Compared with LBA, CBA had a shorter procedural duration. There was a higher incidence of transient but not persistent phrenic nerve palsy after CBA.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=272607 Identifier (CRD42021272607).

Impact of Pulsed-Field Ablation on Intrinsic Cardiac Autonomic Nervous System After Pulmonary Vein Isolation

BACKGROUND

Although the autonomic reaction such as bradycardia is observed frequently during pulsed-field ablation (PFA)-guided pulmonary vein isolation (PVI), its mechanism and effect on the adjacent intrinsic cardiac autonomic nervous system (ICANS) are unclear.

OBJECTIVES

This study aimed to reveal the clinical impact of PFA on ICANS by investigating the serum S100 increase (ΔS100), a well-known denervation relevant biomarker.

METHODS

Pre- and postprocedural serum S100 analyses were systematically conducted in patients undergoing PVI using either the pentaspline PFA or cryoballoon ablation (CBA) system. ΔS100 release kinetics were compared between both technologies. Cerebral magnetic resonance imaging was conducted to eliminate the effect of central nervous system release.

RESULTS

A total of 97 patients (PFA: n = 54 and CBA: n = 43) were enrolled. Overall S100 increased in both groups with a lower amount in PFA (0.035 μg/L; IQR: 0.02-0.063 μg/L) compared with CBA (0.12 μg/L; IQR: 0.09-0.17 μg/L; P < 0.0001). In cerebral magnetic resonance imaging, silent emboli were detected in 10 patients (18.5%) in PFA and 7 patients (16.3%) in CBA (P = 0.773). Even after excluding patients with cerebral emboli, ΔS100 was lower in PFA. During PFA PVI, 30 patients (56%) demonstrated transient bradycardia in 70 of 210 PVs (35%). ΔS100 was similar between patients with or without transient bradycardia.

CONCLUSIONS

We report a significantly lower S100 release following PFA PVI vs CBA PVI even if silent cerebral emboli were excluded. Notably, vagal response during PFA was not associated with S100 release. These observations are in line with lower nervous tissue destruction of PFA compared with CBA.

Bayesian network meta-analysis comparing hot balloon, laser balloon and cryoballoon ablation as initial therapies for atrial fibrillation

BACKGROUND

Balloon-based catheter ablation (CA) technologies, including hot balloon ablation (HBA), laser balloon ablation (LBA) and cryoballoon ablation (CBA) have been introduced in recent years as alternatives to conventional radiofrequency ablation therapy for atrial fibrillation (AF). However, the results remain controversial concerning the optimal approach. Thus, we conducted a network meta-analysis (NMA) to comprehensively evaluate the efficacy and safety of HBA, LBA and CBA.

METHODS

Clinical trials comparing the efficacy and safety of HBA, LBA and CBA were identified through a systematic search up to October 2022. The primary outcomes of interest were the recurrence of AF and procedure-related complications.

RESULTS

Twenty clinical trials with a total of 1,995 patients were included in the meta-analysis. The NMA results demonstrated that HBA, LBA and CBA had comparable AF recurrence rates (HBA vs. CBA: odds ratio OR = 0.88, 95% credible interval CrI: 0.56-1.4; LBA vs. CBA: OR = 1.1, 95% CrI: 0.75-1.5; LBA vs. HBA: OR = 1.2, 95% CrI: 0.70-2.0) and procedure-related complications (HBA vs. CBA: OR = 0.93, 95% CrI: 0.46-2.3; LBA vs. CBA: OR = 1.1, 95% CrI: 0.63-2.1; LBA vs. HBA: OR = 1.2, 95% CrI: 0.44-2.8). The surface under the cumulative ranking curve (SUCRA) suggested that HBA may be the optimal approach concerning the primary outcomes (SUCRA = 74.4%; 61.1%, respectively). However, HBA (40.1%) had a significantly higher incidence of touch-up ablation (TUA) than LBA (8.5%, OR = 2.8, 95% CrI: 1.1-7.1) and CBA (11.9%, OR = 3.7, 95% CrI: 1.9-7.5). LBA required more procedure time than CBA [mean difference (MD = 32.0 min, 95% CrI: 19.0-45.0 min)] and HBA (MD = 26.0 min, 95% CrI: 5.6-45.0 min), but less fluoroscopy time than HBA (MD = -9.4 min, 95% CrI: -17.0--2.4 min).

CONCLUSIONS

HBA, LBA and CBA had comparable efficacy and safety as initial treatments for AF. HBA ranked highest in the primary outcomes, but at the cost of a higher incidence of TUA and longer fluoroscopy time.

SYSTEMATIC REVIEW REGISTRATION

www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022381954, identifier: CRD42022381954.

Efficacy and safety in patients treated with a novel radiofrequency balloon: a two centres experience from the AURORA collaboration

AIMS

A novel irrigated radiofrequency (RF) balloon (RFB) for pulmonary vein (PV) isolation (PVI) was released in selected centres. We pooled the procedural data on efficacy and safety of RFB-PVI from two high volume German centres.

METHODS AND RESULTS

Consecutive patients with RFB procedures were enrolled. A 3D electroanatomical left atrial map guided the RFB navigation. Every RF delivery lasted 60 s, and duration was automatically reduced to 20 s for electrodes facing the posterior wall. Procedural data and post-procedural endoscopy data (<48 h) were analysed. Data from 140 patients were collected (57% male, 67 ± 11 years, 57% paroxysmal atrial fibrillation). There were 547 PVs identified, and 99.1% could be isolated using solely the RFB. Single-shot PVI was recorded in 330/547 (60%) PVs. Median time to isolation during the first application was 10 s (IQR 8-13). A total of 2.1 ± 1.8 applications per PV were delivered, with the left superior PV requiring more application compared to other PVs. Median procedure and fluoroscopy time were 77 min (61-99) and 13 min (10-17), respectively. Major safety events were recorded only in the first 25 cases at each centre and included 1/140(0.7%) cardiac tamponade, 1/140(0.7%) phrenic nerve palsy, and 2/140 strokes (1.4%). An oesophageal temperature rise was recorded in 81/547 (15%) PVs, and endoscopy detected oesophageal lesions in 7/85 (8%) patients undergoing endoscopy.

CONCLUSION

The RFB showed a high efficacy allowing for fast PVI procedures, and 60% of PVs could be isolated at the first application. Most safety events were recorded during the learning phase. An oesophageal temperature monitoring is suggested: oesophageal lesions were detected in 8% of patients.

3D mapping of phrenic nerve course for radiofrequency pulmonary vein isolation

INTRODUCTION

Phrenic nerve (PN) injury is a rare but severe complication of radiofrequency (RF) pulmonary vein isolation (PVI). The objective of this study was to characterize the typical intracardiac course of the PN with a three-dimensional electroanatomic mapping system, to quantify the need for modification of the ablation trajectory to avoid delivering an ablation lesion on sites with PN capture, and to identify very circumscribed areas of common PNC on the routine ablation trajectory of a RF-PVI, allowing fast and effective PN screening for everyday usage.

METHODS

We enrolled 137 consecutive patients (63 ± 9 years, 64% men) undergoing PVI. A detailed high output (20 mA) pace-mapping protocol was performed in the right (RA) and left atrium (LA) and adjacent vasculature.

RESULTS

The right PN was most commonly captured in the superior vena cava at a lateral (50%) or posterolateral (23%) position before descending along the RA either straight (29%) or with a posterolateral bend (20%). In the LA, beginning deep within the right superior pulmonary vein (RSPV), the right PN is most frequently detectable anterolateral (31%), then descends to the lateral proximal RSPV (23%), and further towards the lateral antral region (15%) onto the medial LA wall (12%). To avoid delivering an ablation lesion on sites with PN capture, modification of ablation trajectory was necessary in 23% of cases, most commonly in the lateral RSPV antrum (81%). No PN injury occurred.

CONCLUSION

PN mapping frequently reveals the close proximity of the PN to the ablation trajectory during PVI, particularly in the lateral RSPV antrum. Routine PN pacing should be considered during RF PVI procedures.

Evolving Role of Catheter Ablation for Atrial Fibrillation: Early and Effective Rhythm Control

Catheter Ablation (CA) is an effective therapeutic option in treating atrial fibrillation (AF). Importantly, recent data show that CA as a rhythm control strategy not only significantly reduces AF burden, but also substantially improves clinical hard endpoints. Since AF is a progressive disease, the time of Diagnosis-to-Intervention appears crucial. Recent evidence shows that earlier rhythm control is associated with a lower risk of adverse cardiovascular outcomes in patients with early AF. Particularly, CA as an initial first line rhythm control strategy is associated with significant reduction of arrhythmia recurrence and rehospitalization in patients with paroxysmal AF. CA is shown to significantly lower the risk of progression from paroxysmal AF to persistent AF. When treating persistent AF, the overall clinical success after ablation remains unsatisfactory, however the ablation outcome in patients with "early" persistent AF appears better than those with "late" persistent AF. "Adjunctive" ablation on top of pulmonary vein isolation (PVI), e.g., ablation of atrial low voltage area, left atrial posterior wall, vein of Marshall, left atrial appendage, etc., may further reduce arrhythmia recurrence in selected patient group. New ablation concepts or new ablation technologies have been developing to optimize therapeutic effects or safety profile and may ultimately improve the clinical outcome.

5S Study: Safe and Simple Single Shot Pulmonary Vein Isolation With Pulsed Field Ablation Using Sedation

BACKGROUND

Pulsed field ablation represents an energy source specific for ablation of cardiac arrhythmias including atrial fibrillation. The aim of the study was to describe the adoption and the process of streamlining procedures with a new ablation technology.

METHODS

All-comer atrial fibrillation patients (n=191; mean age 69±12 years) underwent catheter ablation with a pulsed field ablation ablation device exclusively using analog-sedation. In the validation phase (n=25), device electrogram quality was compared with a circular mapping catheter to assess pulmonary vein isolation and esophageal temperature monitoring was used. In the streamline phase (n=166), a single-catheter approach was implemented. Postprocedural cerebral magnetic resonance imaging was performed in 53 patients. In 52 patients, esophageal endoscopy was performed at day 1 after the procedure. Follow-up was performed using 72 hours Holter ECGs.

RESULTS

On a pulmonary vein basis, pulmonary vein isolation rate was 100% including a single shot isolation rate of 99.5%. The electrogram information of the pulsed field ablation catheter and the circular mapping catheter were 100% congruent. Neither esophageal temperature rises nor esophageal thermal injury were observed. Two minor strokes occurred, presumable due to air embolism during catheter exchanges through the large bore sheath (13.8 F ID). In the streamline phase, reduced procedure times (46±14 versus 38±13 minutes, P=0.004), no further strokes and a low incidence of silent cerebral injury (10/53 patients; 19%) were noted. During short-term follow-up, 17/191 patients (9%) had a atrial tachyarrhythmia recurrence.

CONCLUSIONS

The pulsed field ablation device allows for simple and safe simple single shot pulmonary vein isolation using standard sedation protocols. Procedural speed and efficacy are remarkable and streamlining measures have added safety.

Initial clinical experience of pulmonary vein isolation using the ultra-low temperature cryoablation catheter for patients with atrial fibrillation

BACKGROUND

The iCLAS ultra-low temperature cryoablation (ULTC) system has recently brought to the market. A combination of a newly exploited cryogen and interchangeable stylet enables flexible and continuous lesion creation in atrial fibrillation (AF) ablation. The use of an esophageal warming balloon is recommended when using the system to reduce the potential for collateral esophageal injury.

OBJECTIVE

To describe the initial clinical experience when using ULTC in the AF treatment without general anesthesia (GA).

METHODS

Consecutive patients undergoing AF ablation using ULTC under deep sedation without GA were enrolled. We assessed the procedural data focusing on "single-shot isolation" defined as successful pulmonary vein (PV) isolation after the first application. Esophagogastroduodenoscopy was systematically performed the day after ablation.

RESULTS

A total of 27 AF patients (67% paroxysmal AF) were analyzed. One-hundred-four out of 106 PVs (98.1%) were isolated solely using ULTC. The mean procedure time was 79 ± 30 min. The mean number of applications per PV was 2.6 ± 1.0. Single-shot isolation was achieved in 57 PVs (54%) varying across PVs from left superior- to inferior PVs (40-64%). Single procedure six-month recurrence free rate was 84%. No major complication (cerebrovascular event, pericardial effusion/tamponade, esophageal damage on esophagogastroduodenoscopy) occurred. A single transient phrenic nerve palsy occurred during the right superior PV ablation which had recovered by the 3-month follow up appointment.

CONCLUSIONS

AF ablation using the novel ULTC system seemed feasible without GA and enabled >50% single-shot isolation rate. The promising safety profile has to be confirmed in large-scaled studies. This article is protected by copyright. All rights reserved.

Evaluation of linear lesion formation and thermodynamics by dragging ablation with the third-generation laser balloon

Background

The lesion formation properties of a motorized rotational delivery (RAPID) mode, third-generation laser balloon (LB3) ablation compared to point-by-point laser ablation in patients with atrial fibrillation remain unclear.

Objective

The purpose of this study was to assess lesion characteristics and thermodynamics in LB3 ablation with a RAPID mode in vitro model.

Methods

Chicken muscles were cauterized using LB3 in RAPID mode with 13 W and 15 W and 50% overlapped point-by-point fashion with 7 W/30 seconds, 8.5 W/20 seconds, 10 W/20 seconds, and 12 W/20 seconds. Lesion depth, width, and continuity were compared. Lesion continuity was classified by the visible gap degree categorized from 1 (perfect) to 3 (poor). Thermodynamics and maximum tissue temperatures were assessed under infrared thermographic monitoring. Fifteen and 5 lesions were evaluated per ablation protocol for measurement of lesion size and continuity and for thermographic assessment, respectively.

Results

Lesion depth and width were smaller in RAPID mode laser ablation than point-by-point laser ablation (P <.001). However, RAPID mode laser ablation revealed sufficient mean lesion depth of 5 mm or more. Lesion continuity was 1 (perfect) in all samples in RAPID mode laser ablation and point-by-point laser ablation (P = 1). Infrared thermographic observation demonstrated fast and gapless linear lesion formation with thermal stacking in RAPID mode laser ablation. Maximum tissue temperature was lower in RAPID mode laser ablation than point-by-point laser ablation (P <.001).

Conclusion

RAPID mode LB3 ablation could provide fast, gapless, and acceptable lesion formation with thermal stacking and moderate tissue temperature rise.

Persistent Phrenic Nerve Palsy after Atrial Fibrillation Ablation: Follow-up Data from the Netherlands Heart Registration

Background

Persistent phrenic nerve palsy (PNP) is an established complication of atrial fibrillation (AF) ablation, especially during cryoballoon and thoracoscopic ablation. Data on persistent PNP reversibility is limited because most patients recover <24 h. This study aims to investigate persistent PNP recovery, freedom of PNP‐related symptoms after AF ablation and identify baseline variables associated with the occurrence and early PNP recovery in a large nationwide registry study.

Methods

In this study, we used data from the Netherlands Heart Registration, comprising data from 9549 catheter and thoracoscopic AF ablations performed in 2016 and 2017. PNP data was available of 7433 procedures, and additional follow‐up data were collected for patients who developed persistent PNP.

Results

Overall, the mean age was 62 ± 10 years, and 67.7% were male. Fifty‐four (0.7%) patients developed persistent PNP and follow‐up was available in 44 (81.5%) patients. PNP incidence was 0.07%, 0.29%, 1.41%, and 1.25%, respectively for patients treated with conventional‐RF, phased‐RF, cryoballoon, and thoracoscopic ablation respectively. Seventy‐one percent of the patients fully recovered, and 86% were free of PNP‐related symptoms after a median follow‐up of 203 (113–351) and 184 (82–359) days, respectively. Female sex, cryoballoon, and thoracoscopic ablation were associated with a higher risk to develop PNP. Patients with PNP recovering ≤180 days had a larger left atrium volume index than those with late or no recovery.

Conclusion

After AF ablation, persistent PNP recovers in the majority of patients, and most are free of symptoms. Female patients and patients treated with cryoballoon or thoracoscopic ablation are more prone to develop PNP.

Predicting Phrenic Nerve Palsy in Patients Undergoing Atrial Fibrillation Ablation With the Cryoballoon-Does Sex Matter?

Background: Phrenicus nerve palsy (PNP) is a typical complication during pulmonary vein isolation (PVI) using the cryoballoon with the ominous potential to counteract the clinical benefit of restored sinus rhythm. According to current evidence incidence of PNP is about 5–10% of patients undergoing Cryo-PVI and is more frequent during ablation of the RSPV compared to the RIPV. However, information on patient specific characteristics predicting PNP and long-term outcome of patients suffering from this adverse event is sparse.

Aim of the Study: To evaluate procedural and clinical characteristics of AF patients with PNP during cryoballoon PVI compared to patients without PNP.

Methods and Results: Between 2013 and 2019 we included 632 consecutive AF patients undergoing PVI with the cryoballoon in our study. 84/632 (13.3%) patients experienced a total number of 89 PNP during the ablation procedure. 75/89 (84%) cryothermal induced PNP recovered until the end of the procedure (transient PNP, tPNP), whereas 14/89 (16%) PNP hold beyond the end of the procedure (non-transient PNP, ntPNP). Using multivariate logistic regression, we found that sex and BMI are strong and independent predictors of cryothermal induced non-transient PNP during cryoballoon PVI with an odds ratio of 3.9 (CI: 95%, 1.1–14.8, p = 0.04) for female gender. Interestingly, all patients (14/14, 100%) with a non-transient PNP experienced complete PNP resolution after a mean recovery time of 68 ± 79 days.

Conclusion: Our data indicate for the first time, that female sex and lower BMI are independent predictors for non-transient PNP caused by cryoballoon PVI. Fortunately, during follow up all PNP patients resolved completely with a median recovery time of 35 days.

Phrenic Nerve Injury During Cryoballoon-Based Pulmonary Vein Isolation: Results of the Worldwide YETI Registry

Supplemental Digital Content is available in the text.

Background:

Cryoballoon-based pulmonary vein isolation (PVI) has emerged as an effective treatment for atrial fibrillation. The most frequent complication during cryoballoon-based PVI is phrenic nerve injury (PNI). However, data on PNI are scarce.

Methods:

The YETI registry is a retrospective, multicenter, and multinational registry evaluating the incidence, characteristics, prognostic factors for PNI recovery and follow-up data of patients with PNI during cryoballoon-based PVI. Experienced electrophysiological centers were invited to participate. All patients with PNI during CB2 or third (CB3) and fourth-generation cryoballoon (CB4)-based PVI were eligible.

Results:

A total of 17 356 patients underwent cryoballoon-based PVI in 33 centers from 10 countries. A total of 731 (4.2%) patients experienced PNI. The mean time to PNI was 127.7±50.4 seconds, and the mean temperature at the time of PNI was −49±8°C. At the end of the procedure, PNI recovered in 394/731 patients (53.9%). Recovery of PNI at 12 months of follow-up was found in 97.0% of patients (682/703, with 28 patients lost to follow-up). A total of 16/703 (2.3%) reported symptomatic PNI. Only 0.06% of the overall population showed symptomatic and permanent PNI. Prognostic factors improving PNI recovery are immediate stop at PNI by double-stop technique and utilization of a bonus-freeze protocol. Age, cryoballoon temperature at PNI, and compound motor action potential amplitude loss >30% were identified as factors decreasing PNI recovery. Based on these parameters, a score was calculated. The YETI score has a numerical value that will directly represent the probability of a specific patient of recovering from PNI within 12 months.

Conclusions:

The incidence of PNI during cryoballoon-based PVI was 4.2%. Overall 97% of PNI recovered within 12 months. Symptomatic and permanent PNI is exceedingly rare in patients after cryoballoon-based PVI. The YETI score estimates the prognosis after iatrogenic cryoballoon-derived PNI.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03645577.

Graphic Abstract:

A graphic abstract is available for this article.

Cryoballoon Ablation Strategy in Persistent Atrial Fibrillation

Background: Cryoballoon ablation is established for pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (AF). The objective was to evaluate CBA strategy in consecutive patients with persistent AF in the initial AF ablation procedure.

Material and Methods: Prospectively, patients with symptomatic persistent AF scheduled for AF ablation all underwent cryoballoon PVI. Technical enhancements, laboratory management, safety, single-procedure outcome, predictors of recurrence, and durability of PVI were evaluated.

Results: From 2007 to 2020, a total of 1,140 patients with persistent AF, median age 68 years, underwent cryoballoon ablation (CBA). Median left atrial (LA) diameter was 45 mm (interquantile range, IQR, 8), and Congestive heart failure, Hypertension, Age ≥75 years (doubled), Diabetes mellitus, prior Stroke or TIA or thromboembolism (doubled), Vascular disease, Age 65 to 74 years, Sex category (CHA₂DS₂-VASc) score was 3. Acute isolation was achieved in 99.6% of the pulmonary veins by CBA. Median LA time and median dose area product decreased significantly over time (p < 0.001). Major complications occurred in 17 (1.5%) patients including 2 (0.2%) stroke/transitory ischemic attack (TIA), 1 (0.1%) tamponade, relevant groin complications, 1 (0.1%) significant ASD, and 4 (0.4%) persistent phrenic nerve palsy (PNP). Transient PNP occurred in 66 (5.5%) patients. No atrio-esophageal fistula was documented. Five deaths (0.4%), unrelated to the procedure, occurred very late during follow-up. After initial CBA, arrhythmia recurrences occurred in 46.6% of the patients. Freedom from atrial arrhythmias at 1-, and 2-year was 81.8 and 61.7%, respectively. Independent predictors of recurrence were LA diameter, female sex, and use of the first cryoballoon generation. Repeat ablations due to recurrences were performed in 268 (23.5%) of the 1,140 patients. No pulmonary vein (PV) reconduction was found in 49.6% of the patients and 73.5% of PVs. This rate increased to 66.4% of the patients and 88% of PVs if an advanced cryoballoon was used in the first AF ablation procedure.

Conclusion: Cryoballoon ablation for symptomatic persistent AF is a reasonable strategy in the initial AF ablation procedure.

[Practical guide for safe and efficient cryoballoon ablation for atrial fibrillation : Practical procedure, tips and tricks]

In the current guidelines on treatment of atrial fibrillation, cryoballoon-based catheter ablation of atrial fibrillation is recommended in addition to radiofrequency ablation and has become established as a standard procedure in the clinical routine of many centers for index pulmonary vein isolation. A safe, simplified and often durable pulmonary vein isolation can be achieved by a systematic approach. This review article provides a practical guide for all steps of cryoballoon-based pulmonary vein isolation, including preprocedural preparation and postinterventional follow-up. Both cryoballoon systems currently available on the market are considered.

Laser balloon in pulmonary vein isolation for atrial fibrillation: current status and future prospects

INTRODUCTION

Visually guided laser balloon (LB) catheter has been an established modality dedicated for pulmonary vein (PV) isolation in patients with atrial fibrillation. The newly updated version of this novel device has technically evolved recent years.

AREAS COVERED

This review will summarize the contemporary technical evolution of LB catheter. Available efficacy outcomes and the historical change of ablation style will be evaluated. Furthermore, the future perspectives for clinical practice are discussed.

EXPERT COMMENTARY

The initial LB ablation system provided comparable clinical results in PV isolation with other technologies, but with a unique strategical concept enabling the direct visualization of the tissue to cauterize. With multigenerational development, the LB catheter has been equipped with more compliant balloon for favorable PV occlusion and a robotically motor driven continuous ablation mode (RAPID mode). These technical innovations changed the concept of the ablation strategy using LB catheter as 'point-by-point' into 'single-shot' fashion. The remaining tasks are further improvements such as equipping with real-time recording system of intracardiac electrogram, durable structured balloon and the instrument for visualizing the cauterization area in a 360-degree panoramic view, which includes potential possibilities to develop this novel device to the more optimal device for PV isolation.

Single-sweep pulmonary vein isolation using the new third-generation laser balloon-Evolution in ablation style using endoscopic ablation system

BACKGROUND

The endoscopic ablation system (EAS) is an established ablation device for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). The novel X3 EAS is now equipped with a contiguous circumferential ablation mode (RAPID mode).

AIM

To determine the feasibility of single-shot fashioned ablation using X3.

METHODS

Consecutive patients who underwent AF ablation using X3 were enrolled. We assessed the acute procedural data focusing on "Single-sweep PVI" defined as successful PVI with a single RAPID mode energy application, and on "first-pass isolation" defined as successful PVI after initial circular lesion set.

RESULTS

One hundred AF patients (56% male, age: 68 ± 10 years, 66% paroxysmal AF) were analyzed. A total of 379 of 383 PVs (99%) were isolated with X3. Single-sweep PVI and first-pass-isolation were achieved in 214 PVs (56%) and in 362 PVs (95%), respectively. Single-sweep PVI rates varied across PVs with higher rates at the superior PVs (61.2% vs. inferior PVs: 49.5%, p = .0239) and at PVs with maximal ostial diameter <24 mm (57.6% vs. >24 mm: 36.8%, p = .0151). The mean total procedure and fluoroscopy times were 43.0 ± 10 and 4.0 ± 2 min, respectively. In none of the patients an acute thromboembolic event (stroke or transient ischemic attack) or a pericardial effusion/tamponade occurred. A single transient phrenic nerve palsy was observed.

CONCLUSION

The new X3 EAS allows for single-shot fashioned ablation in terms of single-sweep PVI in half or more of PVs. The new RAPID ablation mode leads to an improved rate of first-pass isolation associated with very short procedure times without compromising safety.

Catheter ablation vs. antiarrhythmic drugs as 'first-line' initial therapy for atrial fibrillation: a pooled analysis of randomized data

AIMS

Catheter ablation (CA) is recommended for patients with atrial fibrillation (AF) after failure of antiarrhythmic drugs (AADs). The role of CA as 'initial therapy' for AF is to be determined.

METHODS AND RESULTS

Following PRISMA guideline an up-to-date pooled analysis of randomized data comparing ablation vs. AADs as first-line therapy for symptomatic AF was performed. The primary outcome was recurrence of atrial tachyarrhythmia. The secondary outcomes were improvement in quality-of-life (QoL) and major adverse events. A total of 997 patients from five randomized trials were enrolled (mean age 57.4 years, 68.6% male patients, 98% paroxysmal AF, mean follow-up 1.4 years). The baseline characteristics were similar between the ablation and AADs group. Overall pooled analysis showed that, as compared with AADs, CA as first-line therapy was associated with significantly higher freedom from arrhythmia recurrence (69% vs. 48%, odds ratio: 0.36, 95% confidence interval: 0.27-0.48, P < 0.001). This significance was maintained in subgroup analyses of 1- and 2-year follow-up (P < 0.001). Catheter ablation was associated with significantly greater improvement in QoL regarding AFEQT score and 36-Item Short-Form Health Survey score. The incidence of serious adverse events between ablation and AADs group (5.6% vs. 4.9%, P = 0.62) was similar.

CONCLUSIONS

Catheter ablation as 'initial therapy' was superior to AADs in maintenance of sinus rhythm and improving QoL for patients with symptomatic paroxysmal AF, without increasing risk of serious adverse events.

Validation of lesion durability following pulmonary vein isolation using the new third-generation laser balloon catheter in patients with recurrent atrial fibrillation

BACKGROUND

The second- and third-generation endoscopic ablation systems (EAS2 and EAS3) have been launched in recent years. We aimed to assess the lesion durability as well as gap localization using the multigenerational novel technologies in patients with recurrent atrial fibrillation (AF).

METHODS

Consecutive patients who underwent second ablation for recurrent AF following the initial pulmonary vein isolation (PVI) with EAS2 or EAS3 were retrospectively investigated. The persistent durability of PVI, gap localization at the second procedure, and procedural/anatomical features of durable PVI were analyzed.

RESULTS

Among 225 patients treated with EAS3 (N = 125) and EAS2 (N = 100), 34 patients (EAS3: 13 patients, 50 PVs, EAS2: 21 patients, 82 PVs) underwent a second procedure because of recurrent AF mean 11.9 ± 9.3 months after the initial procedure. Persistent isolation of all four PVs was recorded in 6 (46.2%) patients in EAS3 group and 4 (19.1%) patients in EAS2 group (p = 0.130). Ninety-one out of 132 (68.9%) PVs were persistently isolated with a higher rate in EAS3 group (82.0% vs. EAS2 group: 61.0%, p = 0.0113). A total of 45 gaps were recorded in 41 PVs. Right superior PV (RSPV) was the predominantly common reconnected vein (15 gaps, 14 PVs) irrespective of generations (EAS3: 4 gaps in 3 PVs and EAS2: 12 gaps in 11 PVs). Logistic multivariate regression analysis revealed ablation without reduced energy dose (5.5-7 W) as an independent predictor of durable PVI [adjusted OR: 3.70, 95% CI (1.408-10.003)], p = 0.008].

CONCLUSION

The technical innovation resulted in a higher lesion durability in EAS3-guided PVI in patients with recurrent AF. The most common gap location was found at RSPV in successor EASs. Ablation without reduced energy was a predictor of durable PVI in successor EASs.

Increased procedural safety of cryoballoon pulmonary vein isolation with a double 120 s freeze protocol

BACKGROUND

Recently a double 120 s freeze cryoballoon (CB) pulmonary vein isolation (PVI) protocol proved to be non inferior to a double 240 s freeze protocol in terms of atrial fibrillation (AF) recurrences. We hypothesized that this approach could also result in an increased procedure safety.

METHODS

Eighty consecutive patients treated with a double 120 s freeze protocol (Group CB120) were compared with 80 previous consecutive patients treated with a single 240 s freeze protocol (Group CB240). Procedures were performed with a temperature probe to monitor the luminal esophageal temperature (LET), using a cut off for cryoenergy interruption of 15°C. During ablation at the septal pulmonary veins (PVs), the phrenic nerve (PN) function was monitored by pacing.

RESULTS

In CB120 and CB240 the rate of single shot isolation was similar in all PVs. Time to isolation was not different between the two groups. Mean minimal esophageal temperature was lower in LSPV and LIPV of the CB240 group. A total of 4/80 patients (5%) of the CB120 group experienced a PN injury, but no persistent form was recorded; 11/80 patients (14%) of the CB240 group experienced a PN injury, three in a persistent form (p = .10). A LET <15°C was recorded in 3/80 patients (4%) in the CB120 group and in 16/80 patients (20%) in the CB240 group (p < .01). Composite rate of energy-related safety events (LET <15°C and PN injury) was significantly lower in the CB120 (34% vs. 9%, p < .01).

CONCLUSIONS

Safety of second generation CB PVI can be increased using a double 120 s freeze protocol.

Pivotal Study of a Novel Motor-Driven Endoscopic Ablation System

[Figure: see text].

Cryoballoon Versus Laserballoon: Insights From the First Prospective Randomized Balloon Trial in Catheter Ablation of Atrial Fibrillation

BACKGROUND

Pulmonary vein isolation (PVI) represents the cornerstone in atrial fibrillation ablation. Cryoballoon and laserballoon catheters have emerged as promising devices but lack randomized comparisons. Therefore, we sought to compare efficacy and safety comparing both balloons in patients with persistent and paroxysmal atrial fibrillation (AF).

METHODS

Symptomatic AF patients (n=200) were prospectively randomized (1:1) to receive either cryoballoon or laserballoon PVI (cryoballoon: n=100: 50 paroxysmal atrial fibrillation + 50 persistent AF versus laserballoon: n=100: 50 paroxysmal atrial fibrillation + 50 persistent AF). All antiarrhythmic drugs were stopped after ablation. Follow-up included 3-day Holter-ECG recordings and office visits at 3, 6, and 12 months. Primary efficacy end point was defined as freedom from atrial tachyarrhythmia between 90 and 365 days after a single ablation. Secondary end points included procedural parameters and periprocedural complications.

RESULTS

Patient baseline parameters were not different between both groups. In all (n=200) complete PVI was obtained and the entire follow-up accomplished. Balloon only PVI was obtained in 98% (cryoballoon) versus 95% (laserballoon) requiring focal touch-up in 2 and 5 patients, respectively. Procedure but not fluoroscopy time was significantly shorter in the cryoballoon group (50.9±21.0 versus 96.0±20.4 minutes; P<0.0001 and 7.4±4.4 versus 8.4±3.2 minutes, P=0.083). Overall, the primary end point of no atrial tachyarrhythmia recurrence was met in 79% (cryoballoon: 80.0% versus laserballoon: 78.0%, P=ns). No death, atrio-esophageal fistula, tamponade, or vascular laceration requiring surgery occurred. In the cryoballoon group, 8 transient but no persistent phrenic nerve palsy were noted compared with 2 persistent phrenic nerve palsy and one transient ischemic attack in the laserballoon group.

CONCLUSIONS

Both balloon technologies represent highly effective and safe tools for PVI resulting in similar favorable rhythm outcome after 12 months. Use of the cryoballoon is associated with significantly shorter procedure but not fluoroscopy time.

Keeping it Simple: Balloon Devices for Atrial Fibrillation Ablation Therapy

Atrial fibrillation is a common disease of increasing prevalence. Catheter ablation has evolved into an established therapeutic option that mainly aims to electrically isolate the pulmonary veins from atrial myocardium. The traditional method comprises point-by-point radiofrequency current ablation guided by electroanatomical mapping and has proven to be effective and safe in experienced hands. However, this approach is technically highly demanding and associated with a long learning curve, limiting its widespread utilization. To address these shortcomings, simplified ablation tools for pulmonary vein isolation are needed. In this context, balloon devices promise to ease the procedure by approaching the entire orifice of a targeted pulmonary vein in a single maneuver. This requires less catheter manipulation in the left atrium and often allows ablation of a large volume of tissue with a single application of ablative energy. Two balloon devices-one using cryoenergy, the other laser energy-have already been established in clinical routine and have demonstrated noninferiority when compared with radiofrequency ablation in large randomized trials. More balloon devices are on the verge of being introduced into clinical practice and bear the potential to expand the interventional electrophysiologist's armamentarium when treating atrial fibrillation. The authors review the use of the established balloon devices available for atrial fibrillation ablation and provide a detailed outlook on upcoming balloon technologies, including 3 different balloons utilizing radiofrequency energy as well as a novel cryoballoon.