A frozen decade: Ten years outcome of atrial fibrillation ablation using a single shot device for pulmonary vein isolation

A new stepwise approach to minimize phrenic nerve injury during cryoballoon pulmonary vein isolation

BACKGROUND

A phrenic nerve injury (PNI) during cryoballoon (CB) pulmonary vein isolation (PVI) continues to represent a limitation of this technique. The objective of this study was to develop a novel technique with the aim of reducing the incidence of PNI.

METHODS

We performed a retrospective analysis of data from two hospitals in patients with symptomatic, drug-resistant atrial fibrillation (AF) over 7 years to evaluate the incidence and clinical characteristics of PNI during cryoballoon PVI. Patients in the intervention group were treated with a new technique consisting of the following consecutive steps: (A) phrenic nerve stimulation near stimulation threshold instead of 10 V stimulation; (B) advanced ablation to the right superior pulmonary vein (PV) using a pre-freezing technique; (C) "pulling away" of the CB after vein isolation and/or after reaching - 40 °C for both right PVs. Two subtypes of PNI were studied: persistent (no recovery to discharge) and transient (recovery to discharge) PNI.

RESULTS

Nine hundred patients with a mean age of 62.3 (± 10.9) years (38% female) were analyzed. Transient PNI occurred in 8/250 patients (3.2%) in the intervention group compared to 39/750 patients (6%) in the control group (p = 0.09). Persistent PNI occurred in one patient (0.4%) in the intervention group compared to 18 (2.8%) in the control group (p = 0.03). Any PNI occurred in 9 patients in the intervention group (3.6%) compared to 57 patients (8.8%) in the control group (p = 0.008).

CONCLUSION

In this retrospective analysis, a new cryo-PVI technique significantly reduces the incidence of PNI, particularly persistent PNI.

Pressure waveform analysis for occlusion assessment significantly reduces contrast medium use in cryoballoon pulmonary vein isolation

BACKGROUND

Pulmonary vein (PV) occlusion is crucial for adequate lesion formation during cryoballoon-guided pulmonary vein isolation (CB-PVI). PV occlusion is usually confirmed by angiographies over the inflated balloon device. The aim of our study was to analyze the safety and efficacy of pressure waveform-based PV occlusion assessment during CB-PVI utilizing a novel fully integrated pressure analysis tool.

METHODS

Consecutive patients with symptomatic atrial fibrillation (AF) scheduled for CB-PVI were prospectively enrolled for pressure waveform-based PV occlusion assessment. A patient cohort receiving conventional angiographies served as control group. Patients with common PV ostia were excluded.

RESULTS

The study group consisted of 40 patients (16 females, mean age was 64.5 ± 9.7, 45% persistent AF). The control group consisted of 40 matched patients. All 160 PVs in the study group were successfully isolated without the use of additional venograms confirming PV occlusion. The mean procedure duration was 69 ± 12 min in the study group with a mean fluoroscopy duration of 11.5 ± 4.4 min. The mean contrast medium volume was 22 ± 9 ml in the study group and 36 ± 12 ml in the control group (p = 0.0001). Mean procedure duration, mean balloon temperatures, and mean ablation application durations did not differ significantly between the study and the control group. No periprocedural complications occurred.

CONCLUSION

CB-PVI utilizing a fully integrated pressure waveform analysis tool to assess PV occlusion is feasible and safe and significantly reduces the amount of contrast medium without impact on procedural parameters and freedom from arrhythmia recurrence.

The Role of P Wave Parameters in Predicting Pulmonary Vein Isolation Outcomes for Paroxysmal Atrial Fibrillation: An Observational Cohort Study

BACKGROUND

Pulmonary vein isolation (PVI) is an effective management method for paroxysmal atrial fibrillation (PAF). The P wave in the 12-lead electrocardiogram (ECG) represents atrial depolarisation. This study aims to utilise the P wave to predict PVI outcomes for PAF.

METHODS

This single-centre retrospective study aimed to predict PVI outcomes using P wave parameters. It included 211 consecutive patients with first PVI for PAF between 2018 and 2019 and targeted the pulmonary veins (PVs). Procedure success was defined by freedom of ECG-documented AF at 12 months. Digital 12-lead ECGs with 1-50 hertz bandpass filters were monitored before the procedure. Corrected P wave duration (PWDc), P wave amplitude (PWV), P wave dispersion (PWDisp), intra-atrial block (IAB), P wave area (PWA), and P wave terminal force in V1 (PTFV1) were measured before ablation and correlated with the outcomes.

RESULTS

Successful PVI occurred in 154 patients (73%). Demographics were similar between both arms. P wave parameters correlated with PVI failure included increased PWDc in all leads except for lead III, aVR, and V3, decreased PWV in lead I (hazard ratio [HR]: 0.7, 95% confidence interval [CI]: 0.53-0.95), lead II (HR: 0.45, 95% CI: 0.22-0.65), aVL (HR: 0.58, 95% CI: 0.22-0.98), and aVF (HR: 0.67, 95% CI: 0.58-0.87), decreased PWA in lead I (HR: 0.55, 95% CI: 0.21-0.76), lead II (HR: 0.48, 95% CI: 0.34-0.87), aVL (HR: 0.65, 95% CI: 0.45-0.96), and aVF (HR: 0.61, 95% CI: 0.32-0.89), and the presence of IAB (HR: 2, 95% CI: 1.4-4.2, p = 0.02). PWDisp and PTFV1 were not correlated with PVI outcome.

CONCLUSIONS

PWDc, PWA, PWV, and IAB are valuable predictors for PVI outcome for PAF at 12 months.

Long-term efficacy and safety of cryoballoon ablation of atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

This meta-analysis evaluated long-term efficacy and safety of cryoballoon ablation (CB) of atrial fibrillation (AF).

METHODS

PubMed, Cochrane Library, and Web of Science were searched until July 31, 2023, for published works investigating efficacy and safety of CB of AF in which mean/median follow-up time was not less than 36 months. Safety was assessed by adverse events. Efficacy was assessed by AF recurrence, defined as any atrial arrhythmias lasting more than 30 s.

RESULTS

A total of 19 clinical studies were included. After an average of 58.1 months of follow-up, the overall AF recurrence rate was about 37%. The predictors of recurrence were duration of AF (HR 1.00; 95% CI [1.00 ∼ 1.01]), early recurrence of atrial fibrillation (HR 3.96; 95%CI [1.12 ∼ 14.02]), left atrial diameter (HR 1.04; 95%CI [1.02 ∼ 1.06]), and persistent AF (HR1.47; 95% CI [1.19 ∼ 1.82]). In terms of safety, the incidence of transient phrenic paralysis (PNP) was the highest, about 3%; followed by vascular complications (about 2%); pseudoaneurysm, permanent PNP, and all-cause death was (about 1%); and pericardial effusion and stroke / TIA was very low.

CONCLUSION

CB is associated with low rates of severe complications and reasonable success rates.

Impact of pulmonary vein anatomy and ostial dimensions on long-term outcome after single-shot device-guided cryoablation for paroxysmal atrial fibrillation

BACKGROUND

Cryoballoon (CB)-guided pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). This observational study aimed to assess the role of individual anatomical characteristics to predict long-term freedom from arrhythmia recurrence after CB-guided PVI for paroxysmal AF (PAF).

METHODS

Three hundred fifty three consecutive patients (58 ± 11 years, 56% males), undergoing PVI between 2012 and 2018 were analysed. Individual pulmonary vein (PV) anatomy was assessed using preprocedural cardiac magnetic resonance imaging (MRI). For each PV, the cross-sectional area (CSA) was calculated. The impact of PV characteristics and CSA on long-term AF-free survival was evaluated.

RESULTS

Acute PVI was achieved in all patients. Two hundred twenty-three patients (63%) had a normal PV anatomy (2 left- and 2 right-sided PV). Variant PV anatomy was present in 130 patients (37%). During the observation period of 48 months, AF-recurrence was documented in 167 patients (47 %). Patients with AF-recurrence presented with significantly enlarged right-sided PVs and left superior PVs (LSPVs) (p < 0.001). The presence of left common PVs (LCPVs) (n = 75, Log-rank p < 0.001) as well as right variant PVs (n = 35, Log rank p < 0.001) was associated with a significantly impaired long-term AF-free survival rate as compared to patients with normal PV characteristics.

CONCLUSION

Variant PV anatomy is a good predictor for AF-recurrence. A correlation between an enlarged CSA of right-sided PVs as well as LSPVs and AF-recurrence was documented.

A frozen decade: Ten years outcome after cryoballoon pulmonary vein isolation

Cryoballoon (CB) ablation has emerged as an established gold standard for PVI. Since its introduction into clinical practice, more than one million patients worldwide suffering from symptomatic AF have been treated with different versions of this first real single-shot device. High acute and midterm clinical success, a very beneficial safety profile, short learning curves and high procedural reproducibility are strongly associated with CB guided PVI. Though there is a great amount of data on acute efficacy and short- as well as midterm clinical outcome available, studies reporting on long-term arrhythmia-free survival and on long-term safety of CB-PVI is lacking. This article is protected by copyright. All rights reserved.