Two-year clinical outcome after a single cryoballoon ablation procedure: A comparison of first- and second-generation cryoballoons

Association between baseline glycated hemoglobin level and atrial fibrillation recurrence following cryoballoon ablation among patients with and without diabetes

OBJECTIVES

The study aims to assess the effect of baseline glycated hemoglobin (HbA1c) levels on atrial fibrillation (AF) recurrence following cryoballoon ablation in patients with and without diabetes.

METHODS

Consecutive AF patients receiving first cryoballoon ablation between April 2018 and April 2021 were included. AF recurrence and other clinical outcomes were recorded for a minimum of 12 months post-ablation, with regular assessments at 3, 6, and 12 months, followed by annual check-ups. The primary outcome was AF recurrence after ablation at longest follow-up. Multivariate Cox proportional hazards regression models were utilized to calculate the hazard ratio (HR) and 95% CI per standard deviation (SD) increase of baseline HbA1c level.

RESULTS

335 patients were included in the analysis. The mean age was 61.7 years, 61.8% were male. 12.8% had type 2 diabetes, and 81.7% of patients had paroxysmal AF. The median level of HbA1c was 5.3%, and the mean CHA2DS2-VASc score was 1.8. All cryoballoon ablation procedures, utilizing a 28-mm balloon, achieved successful pulmonary vein isolation. Over a median follow-up of 18 months, 105 patients (31.3%) experienced AF recurrence. In multivariate Cox proportional hazards analysis, a higher HbA1c level, persistent AF (HR 1.91, 95% CI 1.08 to 3.39, P = 0.026), alcohol consumption (HR 2.67, 95% CI 1.33 to 5.37, P = 0.006), and Nadir RSPV (HR 1.04, 95% CI 1.00 to 1.08, P = 0.005) were significant predictors of AF recurrence. Per-SD increase of HbA1c was associated with a 1.75-fold increase risk of AF recurrence (HR 1.75, 95% CI 1.39 to 2.21, P < 0.001). Subgroup analysis revealed that a higher HbA1c level was associated with a higher risk of AF recurrence in patients with and without diabetes, and in patients with paroxysmal and persistent AF.

CONCLUSION

Baseline HbA1c level was an independent predictor of AF recurrence following cryoablation, both in patients with and without diabetes.

Predictive value of premature atrial complex characteristics in pulmonary vein isolation for patients with paroxysmal atrial fibrillation

BACKGROUND

Premature atrial complexes from pulmonary veins are the main triggers for atrial fibrillation in the early stages. Thus, pulmonary vein isolation is the cornerstone of catheter ablation for paroxysmal atrial fibrillation. However, the success rate remains perfectible.

AIM

To assess whether premature atrial complex characteristics before catheter ablation can predict pulmonary vein isolation success in paroxysmal atrial fibrillation.

METHODS

We investigated consecutive patients who underwent catheter ablation for paroxysmal atrial fibrillation from January 2013 to April 2017 in two French centres. Patients were included if they were treated with pulmonary vein isolation alone, and had 24-hour Holter electrocardiogram data before catheter ablation available and a follow-up of≥6 months. Catheter ablation success was defined as freedom from any sustained atrial arrhythmia recurrence after a 3-month blanking period following catheter ablation.

RESULTS

One hundred and three patients were included; all had an acute successful pulmonary vein isolation procedure, and 34 (33%) had atrial arrhythmia recurrences during a mean follow-up of 30±15 months (group 1). Patients in group 1 presented a longer history of atrial fibrillation (71.9±65.8 vs. 42.9±48.4 months; P=0.008) compared with those who were "free from arrhythmia" (group 2). Importantly, the daily number of premature atrial complexes before catheter ablation was significantly lower in group 1 (498±1413 vs. 1493±3366 in group 2; P=0.028). A daily premature atrial complex cut-off number of<670 predicted recurrences after pulmonary vein isolation (41.1% vs. 13.3%; sensitivity 88.2%; specificity 37.7%; area under the curve 0.635; P=0.017), and was the only independent predictive criterion in the multivariable analysis (4-fold increased risk).

CONCLUSION

Preprocedural premature atrial complex analysis on 24-hour Holter electrocardiogram in paroxysmal atrial fibrillation may improve patient selection for pulmonary vein isolation.

Are routine cryoballoon procedural characteristics predictive of atrial arrhythmia recurrence in the long term?

BACKGROUND

Cryoballoon ablation is an effective procedure to treat atrial fibrillation (AF). However, AF recurrence rate at 1-year follow-up is approximately 20% despite improvements in ablation technique.

AIM

To find factors predictive of AF recurrence following a first pulmonary vein isolation procedure using a second-generation cryoballoon (PVI-2CB).

METHODS

This was an observational, retrospective, single-centre study. From June 2012 to April 2017, all patients who had a PVI-2CB procedure and a scheduled follow-up at Rouen University Hospital were included. The primary endpoint was atrial arrhythmia (AA) recurrence (e.g. AF, flutter or tachycardia), considering a blanking period of 2 months following the procedure. Secondary endpoints were procedural variables for each pulmonary vein (successful isolation, time to disconnection, total cryoballoon application time, number of cryoballoon applications, level of occlusion during cryoballoon application leading to successful disconnection and lowest temperature reached during successful cryoballoon application), occurrence of redo procedures, use of antiarrhythmic drugs and adverse events.

RESULTS

The initial population consisted of 239 patients; six were excluded for lack of procedural variable data, giving an analysed population of 233 patients. The AA recurrence rate was 36.9% (mean follow-up 25±14 months). Mean time to AA recurrence was 10±12 months. No procedural variable was found to be predictive of AA recurrence. Only major left atrial enlargement (defined as diameter>50mm or left atrial area>30cm² or left atrial volume>50mL/m²) was predictive (odds ratio 2.70, 95% confidence interval 1.54-4.72; P=0.001). Forty-one patients had redo procedures (17.6% of analysed population); in this subgroup, 75.6% had at least one pulmonary vein reconnected, mainly the right inferior pulmonary vein.

CONCLUSIONS

At long-term follow-up, up to one-third of patients had AA recurrence after PVI-2CB. Important atrial remodelling was the only factor predictive of AA recurrence, whereas no procedural variable was found to be predictive.

Second-generation cryoballoon vs. contact-force sensing radiofrequency catheter ablation in atrial fibrillation: a meta-analysis of randomized controlled trials

OBJECTIVES

It is imperative to understand the influence of second-generation cryoballoon (CB-2) and contact-force sensing radiofrequency ablation (CF-RF) on clinical outcomes in atrial fibrillation (AF). This updated meta-analysis of randomized controlled trials (RCTs) examined the efficacy and safety of CB-2 vs. CF-RF in patients with AF.

METHODS

RCTs on the use of CB-2 vs. CF-RF in patients with AF were included. The primary outcome was the recurrence of AF, and the key secondary outcomes included serious complications, acute pulmonary vein isolation (PVI), procedure duration, and fluoroscopy time.

RESULTS

A total of 261 articles were identified, and five studies with a total of 845 participants were included in the study. A total of 93% of participants had paroxysmal AF, 7% of participants had persistent AF, and none of participants had permanent AF. There were 499 participants in the CB-2 arm and 346 in the CF-RF arm. AF recurrence was comparable in the CB-2 group (30.3%) and the CF-RF group (29.2%) (OR = 0.93; 95%CI = 0.56-1.54; P = 0.79; I² = 48%). There were no statistical differences in acute PVI (P = 0.92; I² = 0%) and serious complications (P = 0.87; I² = 47%) between the two groups. The procedure duration was shorter in the CB-2 group than in the CF-RF group (MD = - 13.39; 95%CI = - 15.58, - 7.19; P < 0.0001; I² = 59%).

CONCLUSION

Our study demonstrated that CB-2 and CF-RF had comparable recurrences of AF and similar incidences of serious complications in AF patients during the ablation process.

Strategies to Improve the Outcome of Cryoballoon Ablation in the Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is a common arrhythmia contributing to severe outcomes, including cardiac dysfunction and stroke, and it has drawn great attention around the world. Drug therapies have been available for many years to terminate AF and control heart rate. However, the results from clinical studies on drug therapies have been discouraging. Mounting evidence indicates that radiofrequency catheter ablation (RFCA) is a safe and effective method to maintain sinus rhythm, especially in patients who are drug intolerant or for whom the drugs are ineffective, although it is a technically demanding and complex procedure. Fortunately, a novel application, cryoballoon ablation (CBA), with outstanding characteristics has been widely used. Great outcomes based on CBA have manifested its significant role in the treatment of AF. However, how to improve the safety and efficacy of CBA is a question that has not been well-answered. Would it be helpful to develop a different generation of cryoballoon? Is bonus freezing beneficial, or not? Is it better to prolong freezing time? Dose CBA combined with RFCA bring higher success rates? In this review, we comprehensively summarized useful applications for improving outcomes of CBA in AF patients.

Treatment of Atrial Fibrillation Using Ablation Index-Guided Contact Force Ablation: A Matching-Adjusted Indirect Comparison to Cryoballoon Ablation

Introduction

Ablation Index, also known as VISITAG SURPOINT™, is a novel lesion-quality marker that improves outcomes in radiofrequency (RF) catheter ablation of atrial fibrillation (AF). There is no direct evidence on the comparative effectiveness of RF ablation with Ablation Index and cryoballoon (CB). The objective of the present study was to conduct a matching-adjusted indirect comparison (MAIC) using individual patient-level data (IPD) to compare the effectiveness of RF ablation with Ablation Index to that of CB on recurrence of atrial arrhythmias 12 months after catheter ablation in patients with paroxysmal AF (PAF).

Methods

Individual patient-level data for RF ablation with Ablation Index were obtained from two studies: Solimene et al. [J Interv Card Electrophysiol 54(1):9–15, 2019] and Hussein et al. [J Cardiovasc Electrophysiol 28(9):1037–1047, 2017]. Comparable CB studies identified from a systematic literature review were pooled. Prognostic variables for adjustment were ranked a priori by several practicing electrophysiologists. In the absence of a common treatment arm between the Ablation Index and CB studies, an unanchored MAIC was conducted. Primary analysis compared the Solimene et al. study to pooled CB studies. A secondary analysis compared pooled RF ablation with Ablation Index studies to pooled CB studies. Several scenario and sensitivity analyses were conducted.

Results

Primary analyses showed statistically significant reductions in the rate of arrhythmia recurrence with RF ablation with Ablation Index compared to CB in unmatched, unadjusted (HR 0.50, 95% CI 0.27–0.95) and matched (0.42, 0.21–0.86) analyses. Greater reductions in the rate of arrhythmia recurrence that favored RF ablation with Ablation Index were observed after matching and adjusting for age (0.41, 0.20–0.85), age and left ventricular ejection fraction (0.37, 0.16–0.88), and age, sex, and left ventricular ejection fraction (0.30, 0.13–0.71). Secondary and sensitivity analyses showed similar reductions.

Conclusions

Radiofrequency ablation with Ablation Index was associated with reductions in recurrence of atrial arrhythmias at 12 months compared to CB in unmatched and unadjusted, matched, and matched and adjusted comparisons.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-019-01173-4) contains supplementary material, which is available to authorized users.

Comparative effectiveness of catheter ablation devices in the treatment of atrial fibrillation: a network meta-analysis

Atrial fibrillation (AF) ablation is most commonly performed using radiofrequency (RF) and cryoballoon (CB) catheters. Ablation Index is a novel lesion-quality marker associated with improved outcomes in RF ablation. Due to lack of direct comparative evidence between the latest generations of technologies, there is uncertainty regarding the best treatment option. Aim: To conduct a network meta-analysis to evaluate the comparative effectiveness of RF with Ablation Index to other catheter ablation devices in the treatment of AF. Methods: Searches for randomized and nonrandomized prospective comparative studies of ablation catheters were conducted in multiple databases. The outcome of interest was 12-month freedom from atrial arrhythmias after a single ablation procedure. Studies were grouped as high-, low- and unclear-quality based on study design and balanced baseline patient characteristics. Bayesian hierarchical network meta-analysis was conducted and results presented as relative risk ratios with 95% credible intervals (CrIs). Results: 12 studies evaluating five different catheter ablation devices were included. Radiofrequency ablation with Ablation Index was associated with statistically significantly greater probability of 12-month freedom from atrial arrhythmias than Arctic Front (relative risk: 1.77; 95% CrI: 1.21-2.87), Arctic Front Advance™ (1.41; 1.06-2.47), THERMOCOOL™ (1.34; 1.17-1.48) and THERMOCOOL SMARTTOUCH™ (1.09; 1-1.3). Results were robust in multiple sensitivity analyses. Conclusion: Radiofrequency catheter with Ablation Index is superior to currently available options for 12-month freedom from atrial arrhythmias after AF ablation. This study provides decision-makers with robust, pooled, comparative evidence of the latest ablation technologies.

Atrial fibrillation ablation using cryoballoon technology: Recent advances and practical techniques

Atrial fibrillation (AF) affects 1-2% of the population, and its prevalence is estimated to double in the next 50 years as the population ages. AF results in impaired patients' life quality, deteriorated cardiac function, and even increased mortality. Antiarrhythmic drugs frequently fail to restore sinus rhythm. Catheter ablation is a valuable treatment approach for AF, even as a first-line therapy strategy in selected patients. Effective electrical pulmonary vein isolation (PVI) is the cornerstone of all AF ablation strategies. Use of radiofrequency (RF) catheter in combination of a three-dimensional electroanatomical mapping system is the most established ablation approach. However, catheter ablation of AF is challenging even sometimes for experienced operators. To facilitate catheter ablation of AF without compromising the durability of the pulmonary vein isolation, "single shot" ablation devices have been developed; of them, cryoballoon ablation, is by far the most widely investigated. In this report, we review the current knowledge of AF and discuss the recent evidence in catheter ablation of AF, particularly cryoballoon ablation. Moreover, we review relevant data from the literature as well as our own experience and summarize the key procedural practical techniques in PVI using cryoballoon technology, aiming to shorten the learning curve of the ablation technique and to contribute further to reduction of the disease burden.