Anatomical and procedural predictors of pulmonary vein stenosis in the setting of second-generation cryoballoon ablation

Best Practice Guide for Cryoballoon Ablation in Atrial Fibrillation: The Compilation Experience of More than 1000 Procedures

Nowadays, the cryoballoon (CB) constitutes an established alternative to radio frequency (RF) ablation for pulmonary vein isolation (PVI), which offers the possibility to isolate the PVs with a single application. Since the introduction of the second-generation CB, we prospectively collected our data to optimize the procedure on >1000 consecutive patients who underwent CB PVI performed in our center. It is expected that subsequent guidelines will suggest first-line PVI through CB in patients with paroxysmal AF with a class I indication. Indeed, in the long-term follow-up (36 months) of the EARLY-AF trial, CB had a lower incidence of persistent atrial fibrillation episodes compared to the anti-arrhythmic drugs group. We now review the current best practices in an effort to drive consistent outcomes and minimize complications. PV isolation through CB is the most studied single-shot technique for atrial fibrillation ablation, having shown the potential to alter the natural history of the arrhythmia. Several procedural tips and tricks can improve procedural flow and effectiveness. In the present article we provided not only technical details but measurable biophysical parameters that can reliably guide the operator into achieving the best outcome for his patients.

Characteristics of anatomical difficulty for cryoballoon ablation: insights from CT

Background

The limited availability of balloon sizes for cryoballoon leads to anatomical limitations for pulmonary vein (PV) isolation. We conducted a comprehensive systematic analysis on procedural success rate, atrial fibrillation (AF) recurrence rate and complications of cryoballoon ablation in association with the anatomy of the left atrium and PV based on preprocedural CT to gain insights into proper treatments of patients with AF using cryoballoon.

Method

A systematic search of literature databases, including PubMed, Web of Science and Cochrane Library, from the inception of each database through February 2021 was conducted. Search keywords included ‘atrial fibrillation’, ‘cryoballoon ablation’ and ‘anatomy’.

Results

Overall, 243 articles were identified. After screening, 16 articles comprising 1396 patients were included (3, 5 and 8 for acute success, AF recurrence and complications, respectively). Regarding acute success and AF recurrences, thinner width of the left lateral ridge, higher PV ovality, PV ostium-bifurcation distance, shorter distance from the non-coronary cusp to inferior PVs, shallower angle of right PVs against the atrial septum and larger right superior PV (RSPV) were associated with poor outcomes. Regarding complications, shorter distance between the RSPV ostium and the right phrenic nerve, larger RSPV-left atrium angle, larger RSPV area and smaller right carina width were associated with incidences of phrenic nerve injury.

Conclusion

This study elucidated several key anatomical features of PVs possibly affecting acute success, AF recurrence and complications in patients with AF using cryoballoon ablation. CT analysis has helped to describe benefits and anatomical limitations for cryoballoon ablation.

Anatomical changes in the pulmonary veins and left atrium after cryoballoon ablation

BACKGROUND

The anatomical changes in pulmonary veins (PVs) after cryoballoon ablation (CBA) are unclear. We aimed to determine the morphological changes in the PVs and left atrium (LA) along with the predictive factors for clinical PV stenosis.

METHODS

We analyzed data of 320 PVs from 80 patients who underwent CBA for atrial fibrillation (age: 62 ± 10 years, 59 males). All patients underwent pre- and post-procedural cardiac computed tomography. We defined clinical PV stenosis when the cross-sectional area decreased by more than 50%.

RESULTS

The average ostial PV area and LA volume decreased significantly after CBA (pre- vs post-CBA; 2.4 ± 1.0 cm² vs 2.3±1.1 cm² , P < .001, 75.0 ± 23.2 cm³ vs 70.7 ± 21.9 cm³ , P < .001, respectively). There was a significant correlation between the reduction rates of the PV area and those of LA volume (R = 0.411, P < .001). The larger preoperative PV area and greater reduction in LA volume were associated with advanced PV narrowing. Clinical PV stenosis was observed in six PVs, was more common in females (male vs female; 0.8% vs 4.8%, P = .043), and tended to be more frequent in left PVs (left PVs vs right PVs; 3.1% vs 0.6%: P = .107), irrespective of the LA volume reduction.

CONCLUSIONS

The significant reduction of the ostial PV area occurred after CBA, which correlated with the reduction rate of LA volume. The narrowing of the PV was partly produced by the LA volume reduction. Clinical PV stenosis was more common in females and tended to be more frequent in left PVs.

Acute Procedural Complications of Cryoballoon Ablation: A Comprehensive Review

Catheter ablation is increasingly performed for treatment of atrial fibrillation (AF). Balloon based procedures have been developed aiming at safer, easier and more effective treatment as compared to point to point ablation. In the present review article, we aimed to discuss acute procedural complications of cryoballoon ablation.

The Impact of Advances in Atrial Fibrillation Ablation Devices on the Incidence and Prevention of Complications

The number of patients with atrial fibrillation currently referred for catheter ablation is increasing. However, the number of trained operators and the capacity of many electrophysiology labs are limited. Accordingly, a steeper learning curve and technical advances for efficient and safe ablation are desirable. During the last decades several catheter-based ablation devices have been developed and adapted to improve not only lesion durability, but also safety profiles, to shorten procedure time and to reduce radiation exposure. The goal of this review is to summarise the reported incidence of complications, considering device-related specific aspects for point-by-point, multi-electrode and balloon-based devices for pulmonary vein isolation. Recent technical and procedural developments aimed at reducing procedural risks and complications rates will be reviewed. In addition, the impact of technical advances on procedural outcome, procedural length and radiation exposure will be discussed.