Safety and Efficacy Using the Second-Generation Cryoballoon in Patients With Atrial Fibrillation and a Common Ostium of Inferior Pulmonary Veins

Novel cryoballoon technology for atrial fibrillation ablation: Impact of pulmonary vein variant anatomy, cooling characteristics, and 1-year outcome from the CHARISMA registry

BACKGROUND

No data have been reported on cooling characteristics and the impact of variant pulmonary vein (PV) anatomy on atrial fibrillation (AF) recurrences after POLARx cryoballoon (CB) ablation.

OBJECTIVE

The purpose of this study was to analyze the impact of PV anatomy variants and cooling characteristics after CB ablation from a large multicenter prospective registry.

METHODS

The primary end point was defined as 1-year absence of any atrial tachyarrhythmias (ATAs: AF/atrial flutter/atrial tachycardia). Correlation between ATA recurrences and anatomy variants/cooling characteristics were evaluated. The secondary outcome was the rate of major periprocedural complications.

RESULTS

A total of 429 consecutive patients diagnosed with paroxysmal AF (83.4%) or persistent AF (peAF; 16.6%) were enrolled. Twenty-eight patients (6.6%) exhibited an anatomical variant (common ostium: 4.0%; adjunctive PV: 2.6%). Nadir temperature, thaw time, and total deflation time were different between standard PVs and PV variants. After the blanking period, over a mean of 431 ± 99 days of follow-up, 63 patients (14.7%) suffered an ATA recurrence. Patients with recurrences had both a shorter thaw time (18.5 ± 7 seconds vs 19.8 ± 7 seconds; P = .0012) and a shorter total deflation time, whereas time to isolation was longer (57.4 ± 42 seconds vs 49.1 ± 33 seconds; P = .04). Patients with anatomy variants showed a similar ATA recurrence rate (5 of 28 [17.9%]) to the standard PV anatomy group (58 of 401 [14.5%]) (P = .584), with a hazard ratio (HR) of 1.43 (95% confidence interval [CI] 0.49-4.13; log-rank, P = .4384). After adjusting for confounders, heart failure (HR 4.12; 95% CI 1.75-9.73; P = .0013) and peAF (HR 1.81; 95% CI 1.03-3.18; P = .0433) remained associated with ATA recurrence during follow-up.

CONCLUSION

The POLARx CB system demonstrated long-term efficacy, along with a safe profile, in both patients with paroxysmal AF and those with peAF, regardless of the presence PV variants. Time to isolation was longer in patients with ATA recurrences during follow-up.

CLINICAL TRIAL REGISTRATION

Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA).

CLINICALTRIALS

gov identifier: NCT03793998. Registration date: January 4, 2019.

Best practices IV in cryoballoon ablation of atrial fibrillation: Important clinical and practical differences for new compliant and size-adjustable cryoballoon systems

BACKGROUND

This paper aims to review and compare the mechanical and technical similarities and differences between the Arctic Front series cryoballoons from Medtronic and the next-generation cryoballoons, including POLARx and POLARx FIT from Boston Scientific and Nordica from Synaptic. As cryoballoon technology continues to evolve, the introduction of lower-pressure and selectable-size balloons presents new considerations for both safety and efficacy of cryoablation of atrial fibrillation.

Catheter Ablation of Atrial Tachycardia after Pulmonary Vein Isolation in a Patient with Common Ostium of Inferior Pulmonary Veins: Case Report

Background and Objectives: Atrial fibrillation (AF), a prevalent cardiac arrhythmia, significantly impacts the quality of life of those affected. The preferred treatment for symptomatic AF, particularly when pharmacological methods fall short, is catheter ablation with pulmonary vein isolation (PVI). While common pulmonary vein (PV) anatomical variants, such as the right accessory pulmonary vein and the common ostium of left pulmonary veins (LCPV), have been studied extensively, their impact on the long-term outcome of PVI is known to be minimal. However, data on less common anomalies, like the common ostium of the left and right inferior pulmonary vein (CIPV), remain scarce in the medical literature. This report aims to shed light on the challenges and outcomes of catheter ablation in a patient with a rare CIPV anomaly. By presenting this case, we contribute to the limited knowledge about the management of such unique anatomical variations in AF treatment and discuss the importance of individualized treatment approaches. Case Presentation: We present a case involving a 56-year-old male diagnosed with AF in 2018. Initial PVI treatment was successful, but the patient experienced symptom recurrence after three years. A preprocedural CT scan before the second ablation revealed a CIPV anomaly. During the repeat procedure, a right superior pulmonary vein (RSPV) reisolation was performed due to identified gaps in the previous ablation line. Post-procedure, the patient maintained a sinus rhythm and reported no further symptoms. Conclusions: This case highlights the importance of recognizing rare PV anatomies like CIPV in the effective management of AF. Tailored ablation strategies, accounting for unique anatomical conditions, can lead to successful long-term outcomes, reinforcing the need for personalized approaches in AF treatment, especially in cases involving complex anatomical variations.

Laser balloon ablation of atrial fibrillation in a patient with a large common inferior trunk: a case report

Background

A balloon-based visually guided laser balloon (LB) ablation (LBA) is as effective and safe as radiofrequency ablation and cryoballoon ablation in curing patients with atrial fibrillation (AF). The third-generation LB is so compliant that it can be inflated to any pressure and size change of up to 41 mm with its maximal expansion, which enables maximum balloon/tissue contact regardless of the size or shape of each pulmonary vein (PV) ostium. A large common inferior trunk (CIT) with a structured, completely independent common ostium of both the right and the left inferior PVs completely conjoined prior to the junction with the left atrium is an extremely rare anatomical variant and an important triggering focus in paroxysmal AF.

Case summary

We present a case of an LBA of AF in a patient with a large CIT of 34 mm in diameter. The laser energy was individually deployed to the right-sided and left-sided antra of the large CIT with the LB positioned at the ostium of the CIT's right and left branches. The complete electrical isolation of the three PVs was achieved. The patient remained stable without any symptoms or AF recurrence 1 year post ablation.

Discussion

The LBA, which is individually deployed to the right-sided and left-sided antra of the large CIT with the third-generation LB positioned at the ostium of the right and left branches of the CIT without laser energy deployment to the posterior wall of the CIT, may be one of the effective strategies for patients with large CITs.

Single ring isolation of pulmonary veins combined with electrical isolation of the superior vena cava in patients with paroxysmal atrial fibrillation

Background

Single-ring isolation (SRI) of the pulmonary veins and the left atrial post wall (LAPW) is an accepted strategy in atrial fibrillation ablation. Whether SRI combined with superior vena cava isolation (SVCI) could further increase the success rate of paroxysmal atrial fibrillation (PAF) has not been reported.

Objective

This study aimed to investigate whether SRI combined with SVCI was feasible and whether it could improve the success rate of PAF ablation.

Methods and results

In our study, sixty patients with PAF from May 2019 to March 2021 were included. SRI plus SVCI was completed with ablation index (AI)-guided high-power ablation. The success rates of SRI and SVCI were 100% and 97%, respectively. One-pass SRI was achieved in 41 out of 60 patients, with 19 out of 60 patients requiring additional ablation to complete the SRI. SVC was not isolated in 2 out of the 60 cases due to concerns about the phrenic nerve (PN) injury. Among the enrolled patients, 2 patients had anomalous pulmonary veins (PVs) (common ostium of inferior PVs). SRI was applied to achieve the PV and PW isolation. After ablation, one patient had an ischemic stroke but recovered without severe morbidity. The average follow-up period was (20 ± 7) months, and single-procedure freedom from atrial arrhythmia was 91.7%. AT/AF recurred in five patients, and 2 out of 5 patients underwent redo ablation. The multi-procedure freedom from atrial arrhythmia was 95%.

Conclusion

Our novel ablation strategy, SRI combined with SVCI, in patients with PAF was feasible and safe, with a relatively high success rate.

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.

Comparison of Using Second-Generation Cryoballoon and Radiofrequency Catheter for Atrial Fibrillation Ablation in Patients With the Common Ostium of Inferior Pulmonary Veins

Aims: To compare the procedural outcomes of cryoballoon ablation (CBA) and radiofrequency ablation (RFA) in atrial fibrillation (AF) patients with the common ostium of inferior pulmonary veins (COIPV) and to explore the effect of COIPV on CBA performance through the assessment of anatomical factors.

Methods: A total of 18 AF patients with COIPV were included. Pulmonary vein isolation (PVI) was performed with second-generation CBA or RFA. The anatomical characteristics of COIPV and procedural outcomes were collected.

Results: The prevalence of COIPV was 0.82% in the enrolled population. PVI was achieved in all pulmonary veins (PVs) without any complications. The “tricircle” strategy was applied for RFA, and the segmental freeze strategy was performed for CBA. Compared with RFA, CBA had shorter procedural time (median: 53.0 vs. 78.0 min, p < 0.001) and longer fluoroscopy time (median: 13.5 vs. 6.0 min, p < 0.001). Higher ovality index of the ostium was seen in patients with ≥4 freezes in inferior PVs [IPVs; 0.95 (0.78–1.05) vs. 0.49 (0.21–0.83), p = 0.047]. During a median of 23.5 months of follow-up, the atrial arrhythmias-free survival after the procedure was comparable between CBA and RFA (p = 0.729).

Conclusion: The second-generation CBA is an efficient and safe alternative for RFA in AF patients with COIPV. Anatomical characteristics of COIPV bring the challenge to the procedure performance of RFA and CBA.