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.

Late arrhythmia recurrence after atrial fibrillation ablation: incidence, mechanisms and clinical implications

Background and objectives Catheter ablation of atrial fibrillation (AF) has become a well-established and widely used therapy, with pulmonary vein isolation (PVI) being the key modality of ablation. However, arrhythmia recurrences after PVI are common, with a relevant number of patients undergoing repeat ablation. Arrhythmia recurrence after PVI may vary regarding time point and mode of recurrence. While early arrhythmia recurrences of AF after PVI are mostly found to be the product of electrical reconnection of the pulmonary veins, the exact mechanisms of very late arrhythmia recurrence, occurring later than 12 months after successful PVI, remain unclear. This review provides an overview on the current evidence on time point and mechanisms of arrhythmia recurrence after PVI focussing on late arrhythmia recurrence. Recent findings The incidence of late arrhythmia recurrence after PVI can lie at a rate of up to 30% according to long-term follow-up studies. Mechanisms of recurrence include electrical reconnection of previously isolated pulmonary veins and development of atrial fibrosis. The use of cryoballoon ablation is likely to be more effective in reducing late arrhythmia recurrences compared to radiofrequency ablation. Novel scores such as the MB-LATER score or the APPLE score may become useful tools in predicting arrhythmia recurrence after PVI. Results and conclusion Late arrhythmia recurrence after PVI is common and leads to a relevant impairment of long-term success. Relevant data are currently limited and exact mechanisms of arrhythmia recurrence remain unclear. Further studies are needed to elucidate pathogenetic mechanisms of late arrhythmia recurrence after PVI in order to improve treatment strategies.

Characteristics of anatomical difficulty for cryoballoon ablation: insights from CT

BackgroundThe 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.MethodA 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’.ResultsOverall, 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.ConclusionThis 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.

Safety and Efficacy of Cryoballoon Ablation of Atrial Fibrillation in relation to the Patients’ Age: Results from a Large Real-World Multicenter Observational Project

Background. The real-world efficacy and safety of atrial fibrillation (AF) ablation in particularly young and elderly patients are still under debate. The aim of the analysis was to investigate the effect of age on the efficacy and safety of cryoballoon ablation (CBA). Methods. 2,534 patients underwent pulmonary vein isolation (PVI) by way of CBA for paroxysmal or persistent drug-resistant and symptomatic AF. The population was divided into age quartiles for evaluation, including (1) <53 years, (2) ≥53 and <61 years, (3) ≥61 and <67 years, and (4) ≥67 years. Furthermore, outcomes were analyzed in patients <41 years, ≥41 and ≤74, and >74 years old. Procedural data and complications were collected, and atrial fibrillation recurrences were evaluated during follow-up. Results. Procedural-related complications (4.1%) were similar in the four subgroups according to age. At the 12-month follow-up, freedom from AF recurrence was 79.2%, 77.4%, 76.8%, and 75.2% ( p = 0.21 ), respectively (with increasing age). At 24-month follow-up, similar incidences of AF recurrence were observed in the four subgroups. When the sample was arbitrarily divided into the three age groups, a higher rate of recurrence was observed in older patients with regard to long-term follow-up (freedom from AF recurrence was 71.8% and 40.9%, respectively, at 12 and 24-month follow-up). In the univariate and multivariate analysis, age did not result in a significant predictor of AF recurrence during follow-up; however, a trend toward higher AF recurrences rates in patients ≥67 years was observed. Conclusion. The data demonstrated a high degree of safety during CBA across all patient ages. Procedural performance and complications were similar between different ages; AF recurrences seem to be more frequent in patients over 74 years.

A Novel Alternately Energy Source Strategy for Re-Ablation of Patients with Recurrent Atrial Fibrillation—Cryoballoon or Radiofrequency Current Energy Ablation. A Case-Control Study

Background: Atrial fibrillation recurrence after circumferential pulmonary vein (PV) isolation was common. Which ablation technique is better for repeat ablation in patients with recurrent atrial fibrillation (AF) remains unclear. We aimed to investigate long-term efficacy of repeat ablation using a novel alternately energy source sequence for re-ablation of patients with recurrent atrial fibrillation: cryoballoon (CB) re-ablation for patients with a failed radiofrequency (RFC) ablation (RFC-CB redo group); radiofrequency energy re- ablation for patients with a failed cryoballoon ablation (CB-RFC redo group).Method: Recurrent AF patients received a repeat ablation procedure in our hospital were enrolled into the study. Demographic and re-ablation procedural characteristics and outcomes were compared among groups.Results: A total of 156 patients were enrolled into the study, 60 patients (38.5%) were in the CB-RFC-redo group and 96 patients (61.5%) were in the RFC-CB-redo group. Longer duration of AF (69.31±64.69 vs 50.78 ±51.48 months; P=0.039) and longer time from first ablation to re-ablation (54.02 ±38.10 vs 14.2 ±10.5 months; P=0.001) were observed in the RFC-CB-redo group as compared with the CB-RFC redo group. Early recurrence rates of atrial fibrillation following initial ablation were equal among groups (RFC-CB-redo group: 42.7% vs CB-RFC-redo group:48.3% , p=0.515).The number of reconnected PVs was significantly higher in the RFC-CB redo group than the CB-RFC redo group (3.36 ± 0.96 vs 1.50 ± 0.81, p=0.01). During the average follow-up of 10.7 ±2.41 months, significantly less AF recurrence was observed in the CB-RFC redo group (16.7% vs 31.3%, p=0.045). In the multivariate analysis, different energy ablation sequence, AF type and early recurrence after the initial ablation were independent predictors of AF recurrence after re-ablation.Conclusions: Alternate energy source sequence strategy for re-ablation of patients with recurrent atrial fibrillation was safe and moderately effective. However, Large multi-center studies must be warranted to provide conclusive evidence.

Effects of Hot Balloon vs. Cryoballoon Ablation for Atrial Fibrillation: A Systematic Review, Meta-Analysis, and Meta-Regression

Background: Balloon-based catheter ablations, including hot balloon ablation (HBA) and cryoballoon ablation (CBA), have rapidly emerged as alternative modalities to conventional catheter atrial fibrillation (AF) ablation owing to their impressive procedural advantages and better clinical outcomes and safety. However, the differences in characteristics, effectiveness, safety, and efficacy between HBA and CBA remain undetermined. This study compares the characteristic and prognosis differences between HBA and CBA.Methods: Electronic search was conducted in six databases (PubMed, Embase, Cochrane Library, Web of Science, ClinicalTrial.gov, and medRxiv) with specific search strategies. Eligible studies were selected based on specific criteria; all records were identified up to June 1, 2021. The mean difference, odds ratios (ORs), and 95% confidence intervals (CIs) were calculated to evaluate the clinical outcomes. Heterogeneity and risk of bias were assessed using predefined criteria.Results: Seven studies were included in the final meta-analysis. Compared with CBA, more patients in the HBA group had residual conduction and required a higher incidence of touch-up ablation (TUA) [OR (95% CI) = 2.76 (2.02–3.77), P = 0.000]. The most frequent sites of TUA were the left superior pulmonary veins (PVs) in the HBA group vs. the right inferior PVs in the CBA group. During HBA surgery, the left and right superior PVs were more likely to have a higher fluid injection volume. Furthermore, the procedure time was longer in the HBA group than in the CBA group [weighted mean difference (95% CI) = 14.24 (4.39–24.09), P = 0.005]. Patients in the CBA group could have an increased risk of AF occurrence, and accepted more antiarrhythmic drug therapy; however, the result was insignificant.Conclusions: HBA and CBA are practical ablation approaches for AF treatment. Patients who received HBA had a higher incidence of TUA and longer procedure time. Clinical outcomes during the mid-term follow-up between HBA and CBA were comparable.Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=259487, identifier: CRD42021259487.

Cryoballoon Ablation for the Treatment of Atrial Fibrillation in Patients With Concomitant Heart Failure and Either Reduced or Preserved Left Ventricular Ejection Fraction: Results From the Cryo AF Global Registry

Background Heart failure (HF) and atrial fibrillation (AF) often coexist; yet, outcomes of ablation in patients with AF and concomitant HF are limited. This analysis assessed outcomes of cryoablation in patients with AF and HF. Methods and Results The Cryo AF Global Registry is a prospective, multicenter registry of patients with AF who were treated with cryoballoon ablation according to routine practice at 56 sites in 26 countries. Patients with baseline New York Heart Association class I to III (HF cohort) were compared with patients without HF. Freedom from atrial arrhythmia recurrence ≥30 seconds, safety, and health care utilization over 12‐month follow‐up were analyzed. A total of 1303 patients (318 HF) were included. Patients with HF commonly had preserved left ventricular ejection fraction (81.6%), were more often women (45.6% versus 33.6%) with persistent AF (25.8% versus 14.3%), and had a larger left atrial diameter (4.4±0.9 versus 4.0±0.7 cm). Serious procedure‐related complications occurred in 4.1% of patients with HF and 2.6% of patients without HF ( P =0.188). Freedom from atrial arrhythmia recurrence was not different between cohorts with either paroxysmal AF (84.2% [95% CI, 78.6–88.4] versus 86.8% [95% CI, 84.2–89.0]) or persistent AF (69.6% [95% CI, 58.1–78.5] versus 71.8% [95% CI, 63.2–78.7]) ( P =0.319). After ablation, a reduction in AF‐related symptoms and antiarrhythmic drug use was observed in both cohorts (HF and no‐HF), and freedom from repeat ablation was not different between cohorts. Persistent AF and HF predicted a post‐ablation cardiovascular rehospitalization ( P =0.032 and P =0.001, respectively). Conclusions Cryoablation to treat patients with AF is similarly effective at 12 months in patients with and without HF. Registration URL: https://www.clinicaltrials.gov ; Unique Identifier: NCT02752737.