Impact of Pulmonary Vein Anatomy on Long-term Outcome of Cryoballoon Ablation for Atrial Fibrillation

The Influence of Pulmonary Veins' Anatomic Features and Catheter Coaxiality on Cryoballoon Ablation Results for Paroxysmal Atrial Fibrillation

A total of 172 consecutive patients with sympathetic paroxysmal atrial fibrillation who received cryoballoon (CB) ablation from 2020 to 2021 were retrospectively analyzed in this study. Catheter coaxiality and anatomic features of pulmonary veins (PVs) on computed tomography images were explored by several parameters and their influence on the cryoablation results was then analyzed. The rate of incomplete CB occlusion was significantly higher for inferior than superior PVs. A multivariate analysis revealed that a short distance (<6.3 mm) from PV ostium to first branch (D-PVB) and a small angle (<32.5°) of first branch were independent predict factors for an incomplete CB occlusion in right inferior PVs (RIPVs). A combination of D-PVB and angle of first branch could elevate the predictor value for an incomplete balloon occlusion with a sensitivity of 0.85 and specificity of 1.0 for RIPVs. For PVs with a perfect balloon occlusion, the best catheter coaxiality was observed in right superior PV while the worst catheter coaxiality was observed in RIPV. A more aggressive catheter manipulation with a "7" or "reverse-U" shape of long sheath could obtain a better catheter coaxiality compared with conventional manipulation strategy for RIPVs. In Conclusion, a short D-PVB and a small angle of first branch were independent predict factors for an incomplete CB occlusion in RIPVs. A more aggressive catheter manipulation strategy was recommended to achieve a complete balloon occlusion and a better catheter coaxiality for RIPVs.

Cryoballoon Ablation for Treatment of Atrial Fibrillation in a Chinese Population: Five-Year Outcomes and Predictors of Recurrence After a Single Procedure

Background

The 5-year outcomes and predictors of atrial fibrillation (AF) recurrence following cryoballoon (CB) ablation in Chinese population remain scarce. Our aim was to report 5-year outcomes and predictors of AF recurrence following a single CB ablation procedure in a Chinese population.

Methods

From December 2013 to August 2016, we included 256 consecutive patients (mean age: 58 ± 10.9 years old; female: 41.0%) with paroxysmal or persistent AF successfully underwent first-generation CB ablation at Fuwai hospital in this prospective study. All patients were followed at least 5 years or when there was recurrent AF. Independent predictors of AF recurrence were determined by Cox proportional hazards regression analysis.

Results

The 5-year success rate after pulmonary vein isolation (PVI) by a single procedure was 59.4%. The recurrence rate was the highest (14.5%) within the first year after the index procedure, and then stabilized. Patients with paroxysmal AF had a higher incidence of freedom from AF recurrence than patients with persistent AF (63.2% vs. 36.4%, log-rank P &lt; 0.01). The overall incidence of complications related to CB ablation was 7.8%. Phrenic nerve injury (PNI) was the most common complication, with an incidence of 3.5%, and patients with PNI were recovered within the 1-year follow-up. Only persistent AF (HR 1.72, 95%CI 1.028–2.854, P &lt; 0.05) was significantly and independently associated with an increased risk of AF recurrence after adjusting for other factors.

Conclusion

Pulmonary vein isolation using CB ablation was safe and effective with an acceptable complication and 5-year success rate in a Chinese population with AF, and persistent AF was the independent predictor for 5-year AF recurrence after a single CB ablation procedure.

Variations in human pulmonary vein ostia morphology: A systematic review with meta-analysis

This study aimed to establish the most accurate and up-to-date anatomical knowledge of pulmonary veins (PV), ostia variations, diameters and ostial area, to provide physicians, especially heart and thoracic surgeons with exact knowledge concerning this area. The main online medical databases, such as PubMed, Embase, Scopus, Web of Science, and Google Scholar, were searched to gather all studies in which the variations, maximal diameter, and ostial area of the PVs were investigated. During the study, the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Additionally, the critical appraisal tool for anatomical meta-analysis (CATAM) was used to provide the highest quality findings. The most common ostia variation is the classical one, which contains the left superior pulmonary vein (LSPV), left inferior pulmonary vein (LIPV), right superior pulmonary vein (RSPV) and right inferior pulmonary vein (RIPV). The mean diameter and ostial area of each pulmonary vein were established in the general population and in multiple variations considering the method of collecting the data and geographical location. Significant variability in PV ostia is observed. Left-sided PVs have smaller ostia than the corresponding right-sided PVs, and the inferior PVs ostia are smaller than the superior. The LCPV ostium size is the largest among all veins analyzed, while the RMPV ostium is the smallest. The results of this meta-analysis are hoped to help clinicians in planning and performing procedures that involve the pulmonary and cardiac areas, especially catheter ablation for atrial fibrillation.

Impact of the left common ostium following pulmonary vein isolation in AF : Systematic review and meta‐analysis

Purpose

Pulmonary vein isolation (PVI) through catheter ablation is the basis for the treatment of atrial fibrillation (AF). The left common ostium (LCO) is a high prevalence anatomical variation and has conflicting results in the effects on the prognosis following ablation. We undertook a systematic review and meta‐analysis of studies that compared the arrhythmia recurrence rate after radiofrequency ablation or cryoablation balloon between patients with normal pattern pulmonary vein and patients with LCO.

Methods and Results

Results were pooled using a fixed or random effect, at the discretion of heterogeneity (>25%), in addition, we associated subgroup analysis in these cases and when clinically indicated. Fourteen non‐randomized studies totaling 3278 patients were included. In analyses using the two energies all patients: OR 1.01 (95% CI 0.84–1.23; P = .90, I² = 67%) and excluding patients with any type of persistent AF (PeAF) and those submitted to linear atrial lesion (LAL) OR 0.80 (95% CI 0.52–1.22; P = .30, I² = 71%). Using CRYO: all patients OR 1.34 (95% CI 1.03–1.74; P = .03, I² = 0%). Using RF: all patients—OR 0.55 (95% CI 0.32–0.95; P = .03, I² = 49%); excluding studies with long duration PeAF and the performance of LAL concomitant—OR 0.45 (95% CI 0.23–0.91; P = .03, I² = 44%).

Conclusion

The results suggest a better prognosis in patients with LCO, submitted to PVI without additional LAL under RF energy in paroxysmal AF and short‐duration PeAF. In patients undergoing CRYO, the presence of LCO suggests a worse prognosis.

Presence of a left common pulmonary vein and pulmonary vein anatomical characteristics as predictors of outcome following cryoballoon ablation for paroxysmal atrial fibrillation

PURPOSE

Pulmonary vein (PV) isolation using cryoballoon ablation (CBA) is a common therapy for patients with drug-refractory paroxysmal atrial fibrillation (PAF). However, initial CBA is successful in only 70-80% of patients. The role of an atypical left common PV (LCPV) and PV anatomical indices on CBA outcomes remains unclear.

METHODS

We followed 80 patients (age 60.7 ± 9.7, 31 % women) with PAF undergoing CBA for 1-year post-procedure for the development of recurrent atrial arrhythmias (AA). Recurrence was assessed by documented AA on EKG or any form of long-term cardiac rhythm monitoring. The presence of an LCPV and individual PV diameters were evaluated using cardiac CT. Based on the maximum and minimum PV ostial diameters, the eccentricity index (EI), ovality index (OI), and PV ostial area (PVA) were calculated for all the veins. A multivariable Cox-proportional hazard model assessed whether the presence of an LCPV or PV anatomic indices (EI, OI, and PVA) predicted recurrence of AA following CBA.

RESULTS

After 1-year follow-up, 19 (23.7%) participants developed recurrence of AA. On multivariable regression, the presence of an LCPV did not predict the recurrence of AA (p = 0.38). Among the PV anatomical indices, on univariate analysis, only the area of the left inferior PV showed a trend towards predicting recurrence, though this result was not significant on multivariate analysis (p = 0.09).

CONCLUSIONS

In patients with PAF, neither the presence of an LCPV nor individual PV anatomical indices predicted recurrence of AA following CBA.

Anatomic predictors of recurrence after cryoablation for atrial fibrillation: a computed tomography based composite score

BACKGROUND

Effective pulmonary vein isolation (PVI) with cryoablation depends on adequate occlusion of pulmonary veins (PV) by the cryoballoon and is therefore likely to be affected by PV and left atrial (LA) anatomical characteristics and variants. Thus, the objective of this study was to investigate the effect of LA and PV anatomy, evaluated by computed tomography (CT), on acute and long-term outcomes of cryoablation for atrial fibrillation (AF).

METHODS

Fifty-eight patients (64.72 + 9.44 years, 60.3% male) undergoing cryoablation for paroxysmal or early persistent AF were included. Pre-procedural CT images were analyzed to evaluate LA dimensions and PV anatomical characteristics. Predictors of recurrence were identified using regression analysis.

RESULTS

60.3% of patients had two PVs on each side with separate ostia, whereas 29.3% and 10.3% had right middle and left common PVs, respectively. The following anatomic characteristics were found to be independent predictors of recurrence: right superior PV ostial max:min diameter ratio > 1.32, left superior PV ostial max:min diameter ratio > 1.2, right superior PV antral circumference > 69.1 mm, right inferior PV antral circumference > 61.38 mm, right superior PV angle > 22.7°. Using these factors, LA diameter and right middle PV, a scoring model was created for prediction of "unfavorable" LA-PV anatomy (AUC = 0.867, p = 0.000009, score range = 0-7). Score of ≥ 4 predicted need for longer cryoenergy ablation (p = 0.039) and more frequent switch to radiofrequency energy (p = 0.066) to achieve PVI, and had a sensitivity of 83.3% and specificity of 82.5% to predict clinical recurrence.

CONCLUSION

CT-based scoring system is useful to identify "unfavorable" anatomy prior to cryo-PVI, which can result in procedural difficulty and poor outcomes.

Supplemental Radiofrequency Ablation After Acutely Unsuccessful Cryoballoon Pulmonary Vein Isolation is Associated With Increased Risk of Recurrent Atrial Fibrillation

Background

Cryoballoon (CB) ablation is widely performed for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Anatomic variations in patient pulmonary vein (PV) anatomy are believed to impact short‐ and long‐term procedural success of CB PVI.

Methods and Results

We hypothesized that failure of initial PV isolation with a standard technique (ie, requiring >2 freeze cycles per PV and/or radiofrequency ablation [RFA] to achieve PV isolation) during index CB PVI procedures would be associated with decreased freedom from AF. We examined a cohort of 177 consecutive patients with drug‐refractory AF who underwent CB PVI with a 28‐mm balloon second‐generation CB device. Mean follow‐up time was 19±9 months. Forty‐three patients had AF recurrence after the 90‐day blanking period after ablation. In 40 patients, acute isolation of one or more PVs could not be achieved by CB ablation with the standard technique (single freeze with or without bonus freeze). To obtain complete acute PVI, 15 patients received extra freeze applications, 20 required supplemental RFA, and 5 received both extra freeze applications and supplemental RFA. Multivariate regression analysis revealed supplemental RFA use during index CB PVI procedures was independently associated with a threefold increased risk of AF recurrence (adjusted hazard ratio, 3.01; 1.45–10.87; P=0.003).

Conclusions

Use of supplemental RFA during CB PVI procedures to assist with isolation of one or more PVs was independently associated with increased risk of AF recurrence. Use of additional freezes to achieve PVI did not increase the risk for recurrent AF.