Cryoballoon ablation of the left atrial posterior wall reduces recurrence of persistent atrial fibrillation in patients with non-paroxysmal atrial fibrillation

Comparative Study of Arctic Front Advance Pro and POLARx Cryoballoons for Linear Ablation of the Left Atrial Roof

BACKGROUND

The effectiveness of cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to pulmonary vein isolation (PVI) using a novel cryoballoon catheter, POLARx, remains unclear.

METHODS

This study compared the efficacy of LA roof line ablation and PVI using POLARx (Boston Scientific) or AFA-Pro (Medtronic) in 100 patients with persistent atrial fibrillation. The right superior pulmonary vein (PV) anchoring and raise-up techniques were consistently used for LA roof line ablation, and rapid right ventricular pacing was applied if the cryoballoon temperature did not reach -40°C.

RESULTS

Complete conduction block at the LA roof could be obtained in all patients with POLARx and in 98.0% of patients with AFA-Pro. Rapid right ventricular pacing was needed in 64.0% of patients with AFA-Pro and in no patients with POLARx. During LA roof line ablation, the nadir cryoballoon temperature was significantly lower with POLARx than with AFA-Pro (right: -54.2°C ± 4.4°C vs. -46.0°C ± 5.4°C; central: -56.8°C ± 4.4°C vs. -45.7°C ± 4.8°C; left: -56.1°C ± 4.3°C vs. -46.1°C ± 5.7°C), and the cryoballoon temperature reached -40°C earlier with POLARx than with AFA-Pro (right: 30.8 ± 7.4 s vs. 74.1 ± 37.7 s; central: 28.2 ± 5.2 s vs. 62.9 ± 30.9 s; left: 29.8 ± 5.8 s vs. 69.6 ± 40.7 s).

CONCLUSION

The nadir cryoballoon temperature with POLARx was approximately 10°C lower than with AFA-Pro, consistently dropping below -40°C during LA roof line CBA. Thus, a complete conduction block of the LA roof line can be easily accomplished using right superior PV anchoring and the raise-up techniques without the need for rapid right ventricular pacing with POLARx.

Pentaspline catheter or cryoballoon for pulmonary vein plus posterior wall isolation in persistent atrial fibrillation: 1-Year outcomes

BACKGROUND

Left atrial posterior wall isolation (LAPWI) plus pulmonary vein isolation (PVI) can be performed with radiofrequency ablation, cryoballoon ablation (CB-A), or, recently, pulsed field ablation (PFA).

OBJECTIVE

The aims of this study were to evaluate efficacy and safety of the pentaspline PFA catheter for PVI + LAPWI in patients with persistent AF undergoing an index ablation procedure and to compare 1-year outcomes of PVI + LAPWI with PFA vs CB-A.

METHODS

All consecutive patients undergoing an index ablation for persistent atrial fibrillation (AF) at Universitair Ziekenhuis Brussel, Belgium, between 2021 and 2023 were retrospectively screened. Inclusion criteria were persistent AF diagnosis following current guidelines, first AF ablation procedure with PVI + LAPWI using the CB-A or the pentaspline PFA catheter, and 1-year follow-up completed.

RESULTS

A total of 160 patients were included (80 with CB-A and 80 with the pentaspline PFA catheter). PVI + LAPWI was performed with success in 160 (100%) patients, and isolation was confirmed at postprocedure high-density mapping in all. Compared with CB-A, PFA was associated with shorter skin-to-skin procedure time, shorter left atrium dwell time, and shorter fluoroscopy time. At survival analysis, freedom from recurrent atrial tachyarrhythmias at 1-year follow-up was similar between the CB-A and PFA groups (76.2% vs 78.8%; log-rank P = .63).

CONCLUSION

In patients with persistent AF undergoing an index catheter ablation, the pentaspline PFA catheter is safe and effective for PVI + LAPWI. Outcomes after pentaspline PFA catheter ablation at 1 year are favorable and similar to those with the CB-A catheter.

Clinical impact of cryoballoon posterior wall isolation using the cross-over technique in persistent atrial fibrillation

BACKGROUND AND AIMS

Successful left atrial posterior wall isolation (LAPWI) using only the cryoballoon (CB) is technically challenging for the treatment of atrial fibrillation (AF). This study aimed to evaluate the efficacy of the cross-over technique, wherein an overlapped ablation is performed by placing the CB from both directions in contact with the LAPW.

METHODS

This was a single-center, retrospective, observational study of 194 consecutive patients with persistent atrial fibrillation (PerAF) who underwent a first-time procedure of pulmonary vein isolation (PVI) + PWI (108 patients) or PVI-only (86 patients) using the CB. The cross-over technique was applied in all LAPWI.

RESULTS

For ablation of the LA roof and bottom, respectively, a mean of 8.6 ± 1.0 (right to left [R→L] 4.3 ± 1.1 and left to right [L→R] 4.3 ± 1.1) and 9.1 ± 1.2 (R→L 4.6 ± 1.6 and L→R 4.5 ± 1.2) CB applications were delivered. LAPW was successfully isolated solely using the CB in 99.1% of patients. Although the PVI + PWI group had significantly longer procedure time, no severe adverse events were observed in either group. During a median follow-up of 19 months, freedom from recurrence of all atrial tachyarrhythmias was achieved in 93.5% of the PVI + PWI group and 72.9% of the PVI-only group (p = .011).

CONCLUSIONS

LAPWI performed solely with the CB using the cross-over technique is feasibly, safe, and was independently associated with a significantly higher freedom from recurrence of atrial tachyarrhythmias compared with PVI alone in patients with PerAF.

Catheter ablation using pulmonary vein isolation with versus without left atrial posterior wall isolation for persistent atrial fibrillation: an updated systematic review and meta-analysis

BACKGROUND

Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation of atrial fibrillation (AF); however, the results are suboptimal for persistent AF. The left atrial posterior wall (LAPW) is thought to be a major additional area in initiation and perpetuation of persistent AF. Therefore, adjunctive ablation of the posterior wall may reduce AF recurrence in patients with persistent AF.

OBJECTIVE

The objective of this study was to compare outcomes of catheter ablation in patients with persistent AF using PVI alone versus a combination of PVI and LAPW isolation.

METHODS

Literature search was conducted in PubMed, PubMed Central, Scopus, and Embase since inception to February 2023. Screening of studies was done via Covidence software. Risk of bias assessment was done using appropriate tools. Data extraction and a narrative synthesis were carried out accordingly.

RESULTS

Ten studies were included, of which five were randomized controlled trials. PVI with LAPW ablation group had significantly lower recurrence of overall atrial tachyarrhythmia (OR 0.47, CI 0.32-0.70) and AF (OR 0.39, CI 0.23-0.69). In sensitivity analysis, freedom from atrial arrhythmias was noted to be significantly higher in the PVI with LAPW ablation group (OR 2.22, CI 1.36-3.64). However, there was no significant difference in occurrence of atrial flutter (OR 1.36, CI 0.86-2.14) or with periprocedural adverse events (OR 1.10, CI 0.60-1.99).

CONCLUSION

LAPW ablation, in addition to PVI, significantly improves the rates of arrhythmia freedom and reduces the recurrence of overall atrial tachyarrhythmia. There was no significant difference in atrial flutter or periprocedural adverse events.

How to perform effective cryoballooon ablation of the left atrial roof: Considerations after experiencing more than 1000 cases

INTRODUCTION

Cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to a pulmonary vein isolation has been expected to improve the clinical outcomes post-atrial fibrillation (AF) ablation. We demonstrated the characteristics and efficacy of CBA of the LA roof through our experience with a large volume of procedures.

METHODS

Among 1036 AF ablation procedures with CBA of the LA roof, 834 patients who underwent a de novo ablation were analyzed.

RESULTS

Complete LA roof line conduction block was obtained in 767 patients (92.0%) solely by CBA (Group A). Compared with the other patients (Group B), the mean nadir balloon temperature during CBA of the LA roof (-44.5 ± 5.6°C for Group A vs. -40.5 ± 7.5°C for Group B, p < .01) and number of cryoballoon applications during the LA roof ablation with a circular mapping catheter located in the left superior pulmonary vein (1.3 ± 0.8 for Group A vs. 1.6 ± 1.0 for Group B, p = .02) were significantly lower in Group A. A multivariate analysis revealed that those were predictors of a complete LA roof conduction block after only CBA. The 1-year Kaplan-Meier atrial arrhythmia free rate estimates were 80.6% for Group A and 59.0% for Group B (p < .01).

CONCLUSION

Complete LA roof line conduction block could be obtained with a cryoballoon without touch-up ablation in most cases. The LA roof CBA with a circular mapping catheter located in the right superior pulmonary vein was preferable to obtaining complete LA roof conduction block, which was important with regard to the clinical outcomes.

Effect of pulmonary vein cryoballoon ablation in dogs with coolant-nitrogen

BACKGROUND

The Arctic Front Advance System with nitrous oxide (N2O) refrigerant is the leading system for the cryoballoon ablation of atrial fibrillation (AF). A novel cryoablation system with nitrogen (N2) refrigerant was developed with technical improvements seeking to improve outcomes. Cryoballoon ablation with the N2 refrigerant may be effective and safe for pulmonary vein isolation (PVI).

METHODS

In total, 16 dogs were included in the study, of which 13 underwent PVI procedures, and 3 served as baseline controls. Cryoballoons (Cryofocus, Int.) with N2 refrigerant were used for the study group, which comprised 8 dogs, and second-generation cryoballoons with N2O refrigerant (Arctic Front Advance; Medtronic, Inc., MN, USA) were used for the control group, which comprised 5 dogs. Three dogs of the study group and 2 dogs of the control group were euthanized on the same day post-ablation. The other 8 dogs of the two groups were euthanized 1 month post-ablation. The removed organs were examined for gross anatomy and histological review.

RESULTS

The average ablation times for each pulmonary vein (PV) in the study group were less than those in the control group (1.1±0.3 vs. 2.0±0.8; P=0.006). The procedure duration of the study group was shorter than that of the control group (379±46 vs. 592±162 s; P=0.013). And the time to isolation (TTI) was similar between the groups. The PVI rate of the single-ablation was higher in the study group than the control group (92.9% vs. 60.0%; P=0.05). In relation to safety, there was no evidence of thrombus, esophageal injury, or pericardial tamponade in any of the dogs. Only 1 incidence of self-limited phrenic nerve paralysis (PNP) was observed in the control group.

CONCLUSIONS

The novel cryoablation system with the N2 refrigerant had better efficacy than and similar safety to that of the system (Medtronic, Int.) with the N2O refrigerant.