Circumferential pulmonary vein isolation as index procedure for persistent atrial fibrillation: a comparison between radiofrequency catheter ablation and second-generation cryoballoon ablation

Global Research Progress on Radiofrequency Ablation in Cardiology

Radiofrequency ablation (RFA) has become a cornerstone in treating cardiac arrhythmias, offering a minimally invasive approach to managing conditions such as atrial fibrillation, ventricular tachycardia, and other rhythm disorders. The historical evolution of RFA, from its early inception to its current state, underscores the technological advancements that have significantly enhanced its efficacy and safety. Global trends indicate a steady increase in the adoption of RFA, with notable research contributions from North America, Europe, and Asia. Comparative studies reveal outcome variability driven by differences in patient populations, procedural techniques, and healthcare infrastructures. Despite its success, RFA faces challenges, including complications related to the procedure, patient selection, and long-term efficacy. Emerging technologies, such as integrating artificial intelligence and enhanced imaging modalities, hold promise for overcoming these barriers and further refining the procedure. Gaps in current research are identified, particularly in understanding the long-term outcomes of RFA and its application in complex arrhythmias. The critical role of RFA in modern cardiology is emphasized, along with the potential for future innovations that could expand its therapeutic utility. This synthesis of the latest evidence provides valuable insights for optimizing the use of RFA in managing cardiac arrhythmias.

Clinical impact of cryoballoon posterior wall isolation using the cross-over technique in persistent atrial fibrillation

BACKGROUND AND AIMS

Successful left atrial posterior wall isolation (LAPWI) using only the cryoballoon (CB) is technically challenging for the treatment of atrial fibrillation (AF). This study aimed to evaluate the efficacy of the cross-over technique, wherein an overlapped ablation is performed by placing the CB from both directions in contact with the LAPW.

METHODS

This was a single-center, retrospective, observational study of 194 consecutive patients with persistent atrial fibrillation (PerAF) who underwent a first-time procedure of pulmonary vein isolation (PVI) + PWI (108 patients) or PVI-only (86 patients) using the CB. The cross-over technique was applied in all LAPWI.

RESULTS

For ablation of the LA roof and bottom, respectively, a mean of 8.6 ± 1.0 (right to left [R→L] 4.3 ± 1.1 and left to right [L→R] 4.3 ± 1.1) and 9.1 ± 1.2 (R→L 4.6 ± 1.6 and L→R 4.5 ± 1.2) CB applications were delivered. LAPW was successfully isolated solely using the CB in 99.1% of patients. Although the PVI + PWI group had significantly longer procedure time, no severe adverse events were observed in either group. During a median follow-up of 19 months, freedom from recurrence of all atrial tachyarrhythmias was achieved in 93.5% of the PVI + PWI group and 72.9% of the PVI-only group (p = .011).

CONCLUSIONS

LAPWI performed solely with the CB using the cross-over technique is feasibly, safe, and was independently associated with a significantly higher freedom from recurrence of atrial tachyarrhythmias compared with PVI alone in patients with PerAF.

Relationship between sodium-glucose cotransporter 2 inhibitors and atrial fibrillation recurrence after pulmonary vein isolation in patients with type 2 diabetes and persistent atrial fibrillation

BACKGROUND

The impact of sodium-glucose cotransporter 2 (SGLT2) inhibitors on the postoperative recurrence of atrial fibrillation (AF) in patients with persistent AF undergoing an initial radiofrequency ablation is not yet established. The objective of this study is to assess the impact of SGLT2 inhibitors on the recurrence of AF after radiofrequency ablation in patients with type 2 diabetes complicated persistent AF.

METHODS

A total of 182 patients with type 2 diabetes and persistent AF, who underwent their first radiofrequency ablation for AF at our center, were enrolled and divided into two groups: the SGLT2 inhibitor group and the non-SGLT2 inhibitor group. The main outcome of the follow-up was the postoperative recurrence of AF.

RESULTS

A total of 49 participants experienced AF recurrence. The use of SGLT2 inhibitors in patients with type 2 diabetes who underwent AF ablation was associated with a significantly lower risk of AF recurrence (adjusted hazard ratio: 0.65; 95% confidence interval: 0.28-0.83; p < .01).

CONCLUSIONS

The use of SGLT2 inhibitors is associated with a decreased risk of arrhythmia recurrence after AF ablation in patients with type 2 diabetes complicated with persistent AF.

A bibliometric analysis from 2013 to 2024 reveals research hotspots and trends in the connection between atrial fibrillation and cryoballoon: An observational study

Using bibliometric analysis, this study attempted to provide an overview of the current state of research and key findings regarding the relationship between atrial fibrillation (AF) and cryoballoons in general. We gathered the literature from the Web of Science (WOS) database covering the last 11 years (2013-2024) pertaining to AF and cryoballoons, and we used Citespace to evaluate the mapping of knowledge. The findings demonstrated that there were 1986 articles concerning AF and cryoballoons, with a faster growth after 2018. The United States, Vrije Universiteit Brussel, and Chierchia, Gian-Battista are the nation, organization, and writer with the highest number of publications. Kuck KH (2016) is the most frequently mentioned reference as well (488). We know that Vrije Universiteit Brusse in the Belgium has emerged as 1 of this discipline's leading research forces based on a 10-year bibliometric investigation. Prominent universities and developed nations form the finest alliances for research on cryoballoons and AF.

Comparison of advanced generation cryoballoon ablation and ablation index-guided pulmonary vein isolation with non-pulmonary vein trigger induction test and additional ablation in paroxysmal atrial fibrillation

BACKGROUND

An ablation index (AI)-guided pulmonary vein isolation (PVI) or 2nd generation cryoballoon (CB)-PVI has been shown to reduce the atrial fibrillation (AF) burden by 99% despite the absence of ablation of non-pulmonary vein (PV) triggers in patients with paroxysmal AF. The purpose of this study was to investigate the effects of PVI alone strategy using 2nd generation CB compared with AI-guided PVI with an additional induction test and subsequent AF trigger ablation.

METHODS AND RESULTS

We investigated 223 patients with symptomatic paroxysmal AF who underwent an initial PVI between August 2018 and August 2020. The study patients were divided into 2 groups: CB-PVI without an induction test (CB-PVI alone group, n = 82) and AI-guided PVI with an induction test and subsequent additional ablation of non-PV triggers (AI-PVI plus group, n = 141). In the AI-PVI plus group, a total of 62 non-PV triggers were induced in 38 patients, and non-PV triggers in 22 patients were completely ablated. The procedure time and left atrium dwell time were significantly shorter in the CB-PVI alone group than AI-PVI plus group. There were no significant differences in the incidence of procedural complications between the 2 groups (P = 0.650). The AF free survival rate in the CB-PVI alone group and AI-PVI plus group was 80% vs. 80% at 24 months (P = 0.969).

CONCLUSIONS

An PVI alone strategy using advanced generation CB did not differ in the clinical outcomes compared with an AI-guided PVI strategy with an induction test and subsequent ablation of non-PV triggers in the patients with paroxysmal AF.

Effects of Inflammatory Cell Death Caused by Catheter Ablation on Atrial Fibrillation

Atrial fibrillation (AF) poses a serious healthcare burden on society due to its high morbidity and the resulting serious complications such as thrombosis and heart failure. The principle of catheter ablation is to achieve electrical isolation by linear destruction of cardiac tissue, which makes AF a curable disease. Currently, catheter ablation does not have a high long-term success rate. The current academic consensus is that inflammation and fibrosis are central mechanisms in the progression of AF. However, artificially caused inflammatory cell death by catheter ablation may have a significant impact on structural and electrical remodeling, which may affect the long-term prognosis. This review first focused on the inflammatory response induced by apoptosis, necrosis, necroptosis, pyroptosis, ferroptosis and their interaction with arrhythmia. Then, we compared the differences in cell death induced by radiofrequency ablation, cryoballoon ablation and pulsed-field ablation. Finally, we discussed the structural and electrical remodeling caused by inflammation and the association between inflammation and the recurrence of AF after catheter ablation. Collectively, pulsed-field ablation will be a revolutionary innovation with faster, safer, better tissue selectivity and less inflammatory response induced by apoptosis-dominated cell death.

Safety of a single bolus administration of heparin without the measurement of activated clotting time during cryoballoon ablation: a prospective randomized controlled trial

BACKGROUND

Single-shot ablation has emerged as an effective technique for index atrial fibrillation (AF) ablation, with an advantage of short procedure time. Although recent guidelines recommend peri-procedural uninterrupted oral anticoagulants (OACs), the intra-procedural anticoagulation strategy remains uncertain under non-vitamin K OACs (NOACs). We investigated procedural safety of a single bolus administration of heparin without activated clotting time (ACT) measurement during cryoballoon ablation (CBA).

METHODS

Two hundred patients (64.2 ± 10.0 years, 70% with non-paroxysmal AF) who underwent CBA with uninterrupted NOACs were randomly assigned to No-ACT group and ACT group. A bolus of heparin (100 U/kg) was routinely administered immediately after transseptal puncture. In the ACT group, an additional injection of heparin (30 U/kg) was administered if ACT at 30 min after the initial bolus was < 300 s.

RESULTS

There were no differences in baseline characteristics including CHA₂DS₂-VASc score between the two groups. The left atrium indwelling and procedure times were 60.4 ± 13.1 min and 78.9 ± 13.9 min, respectively, and not significantly different between the two groups. The mean ACT was 335.2 ± 59.9 s in the ACT group. Any bleeding rate was 3.2% in all patients and there was no statistically significant difference in bleeding complications between the two groups. In the ACT group, groin hematoma, laryngopharyngeal bleeding, and hemoptysis occurred in 3, 1, and 1 patient, respectively. Cardiac tamponade occurred in 1 patient in the No-ACT group. No thromboembolic events occurred during the 30-day follow-up after CBA.

CONCLUSIONS

Single bolus administration of heparin without ACT measurement is a feasible anticoagulation strategy for CBA in patients with uninterrupted NOAC intake.

Safety and efficacy of cryoablation for atrial fibrillation in young patients: A multicenter experience in the 1STOP project

BACKGROUND

Atrial fibrillation (AF) is an uncommon arrhythmia in young adults without structural heart disease, and cryoballoon pulmonary vein isolation (CB-PVI) is an important therapeutic strategy for rhythm control in patients with drug-refractory AF. The aim of this analysis was to evaluate efficacy and safety of CB-PVI in a large cohort of young patients in comparison with middle-aged adults in a real-world setting.

METHODS

From 2012 to 2020, a total of 3033 patients with AF underwent CB-PVI and were followed prospectively in the framework of the 1STOP Clinical Service project, involving 34 Italian centers. Out of 3033 total 1STOP project subjects, a subgroup of 1318 patients were defined which included a YOUNG group (age ≤ 45 years; n = 368) and a MIDDLE-AGED group (age 60-65 years; n = 950).

RESULTS

The acute success rate of PVI did not differ between the two cohorts (99.9 ± 1.3% vs. 99.8 ± 3.2%, p = 0.415). There was no difference in procedural characteristics, and periprocedural complication rates were similar among the two cohort (1.9% vs. 2.3%, p = 0.646). The 12-month freedom from AF recurrence was 88.9% (95% confidence interval [CI]: 84.7-92.0) in the YOUNG cohort and 85.6% (95% CI: 82.9-88.0) in the MIDDLE-AGED group. At 36-month follow-up, freedom from AF recurrence was 72.4% (65.5%-78.2%) and 71.8% (67.7%-75.6%), respectively with no significant difference among groups (p = 0.550).

CONCLUSION

CB-PVI had similar efficacy and safety in YOUNG and MIDDLE-AGED patients. Younger age did not affect acute procedural results, complication rate, or AF recurrence after a single procedure.

Efficacy of left atrial posterior wall isolation guided by lesion size prediction module for non-paroxysmal atrial fibrillation

AIMS

The efficacy of left atrial posterior wall isolation (PWI) is controversial. Lesion durability may be a major cause of arrhythmia recurrence. The use of the lesion size prediction module improves lesion durability. This study aimed to compare the clinical outcomes of pulmonary vein isolation (PVI) alone and PWI in addition to PVI (PVI + PWI) in patients with non-paroxysmal atrial fibrillation (AF) using a lesion size prediction module.

METHODS AND RESULTS

This study is a sub-analysis of the recently published prospective multicentre observational study called ALCOHOL-AF (association of alcohol consumption with outcome of catheter ablation of AF). In this sub-analysis, patients with non-paroxysmal AF in whom PVI alone or PVI + PWI was performed using the lesion size prediction module were included. Freedom from atrial tachyarrhythmia was compared between PVI alone and PVI + PWI groups using propensity score analyses. Of the 3474 patients registered in the ALCOHOL-AF study, 572 patients (age 65.6 ± 10.1 years, male 77.4%, longstanding persistent AF 25.5%) were included in this sub-analysis. We selected 212 patients treated with PVI alone and 212 treated with PVI + PWI using one-to-one propensity score matching. During the follow-up period, atrial tachyarrhythmia recurrence was documented in 92 (43.4%) and 50 (23.6%) patients in the PVI alone and PVI + PWI groups, respectively. Freedom from atrial tachyarrhythmia recurrence without anti-arrhythmic drugs after a single procedure was significantly higher in PVI + PWI than in PVI alone groups (hazard ratio: 0.452, 95% confidence interval: 0.308-0.664, P < 0.001).

CONCLUSION

In this hypothesis-generating study, lesion size prediction module-guided PVI + PWI was associated with better clinical outcomes than PVI alone in patients with persistent or longstanding persistent AF.

Evolving Role of Catheter Ablation for Atrial Fibrillation: Early and Effective Rhythm Control

Catheter Ablation (CA) is an effective therapeutic option in treating atrial fibrillation (AF). Importantly, recent data show that CA as a rhythm control strategy not only significantly reduces AF burden, but also substantially improves clinical hard endpoints. Since AF is a progressive disease, the time of Diagnosis-to-Intervention appears crucial. Recent evidence shows that earlier rhythm control is associated with a lower risk of adverse cardiovascular outcomes in patients with early AF. Particularly, CA as an initial first line rhythm control strategy is associated with significant reduction of arrhythmia recurrence and rehospitalization in patients with paroxysmal AF. CA is shown to significantly lower the risk of progression from paroxysmal AF to persistent AF. When treating persistent AF, the overall clinical success after ablation remains unsatisfactory, however the ablation outcome in patients with "early" persistent AF appears better than those with "late" persistent AF. "Adjunctive" ablation on top of pulmonary vein isolation (PVI), e.g., ablation of atrial low voltage area, left atrial posterior wall, vein of Marshall, left atrial appendage, etc., may further reduce arrhythmia recurrence in selected patient group. New ablation concepts or new ablation technologies have been developing to optimize therapeutic effects or safety profile and may ultimately improve the clinical outcome.

Cryoballoon ablation of persistent atrial fibrillation for de novo pulmonary vein isolation: a single-center follow-up study

BACKGROUND

Pulmonary vein isolation (PVI) alone for persistent atrial fibrillation (PersAF) remains controversial. The characteristics of cryoballoon ablation (CBA) to treat PersAF and the blanking period recurrence are underreported.

METHODS

This study retrospectively analyzed patients with PersAF undergoing second-generation CBA for de novo PVI. The post-procedural efficacy and survival analysis were compared between patients with different PersAF durations. The multivariate Cox regression analysis was used to detect the risk factors for recurrence. Early and long-term recurrence were analyzed relative to each other.

RESULTS

A total of 329 patients were enrolled, with a median PersAF duration of 4.0 months (interquartile range: 2.0-12.0 months); 257 patients (78.1%) were male. Kaplan-Meier analysis of freedom from atrial fibrillation recurrence at 12, 24, and 30 months showed 71.0%, 58.5%, and 54.9%, respectively. Early PersAF had a relatively favorable survival rate and a narrow P-wave duration of restoring sinus rhythm compared with that of PersAF lasting more than three months (P < 0.05). The multivariate Cox regression analysis revealed that PersAF duration and left atrial anteroposterior diameter ≥ 42 mm were the risk factors for atrial fibrillation recurrence after CBA [hazard ratio (HR) = 1.89, 95% CI: 1.01-1.4, P = 0.042; HR = 3.6, 95% CI: 2.4-5.4, P < 0.001, respectively]. The blanking period recurrence predicted the long-term recurrence (P < 0.0001).

CONCLUSIONS

CBA of PersAF had safety and efficacy to reach de novo PVI. The PersAF duration and left atrial size were risk factors for atrial fibrillation recurrence after CBA. Blanking period recurrence was associated with long-term recurrence.

Comparison of cryoballoon and radiofrequency ablation for persistent atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

There is limited data comparing radiofrequency (RF) and cryoballoon (CB) ablation for persistent atrial fibrillation (AF), which tends to have higher recurrence rates following ablation compared to paroxysmal AF.

METHODS

A systematic search of the Embase, PubMed, and Cochrane database was performed for studies comparing RF vs CB ablation for persistent AF. An inverse-variance random-effects model was used to calculate the composite effects.

RESULTS

One randomized and 9 observational studies were identified, with 1650 patients receiving CB and 1706 patients receiving RF ablation. Mean follow-up time ranged from 12 to 48 months. Freedom from recurrent atrial tachyarrhythmia was similar with the two modalities (HR 0.93, 95% CI 0.80 to 1.08, I² 0%). Total complications were similar in both groups (RR 1.05, 95% CI 0.73 to 1.53, I² 0%) although rates of phrenic nerve palsy (PNP) were greater with CB (RR 4.13, 95% CI 1.49 to 11.46, I² 0%). Shorter procedure times were observed with CB (mean reduction 43.77 min, 95% CI 66.45 to 21.09 min, I² 96%) with no difference in fluoroscopy time (mean difference 0.82 min, 95% CI - 11.92 to 13.55 min, I² 100%).

CONCLUSIONS

In persistent AF patients, CB ablation has similar efficacy and overall safety as compared to RF ablation. While CB is associated with significantly shorter procedure times, the improved procedural efficiency with CB is offset by increased rates of PNP and the potential need for touch-up RF ablation.

Clinical Impact of Posterior Wall Isolation in Catheter Ablation for Persistent Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND

The clinical outcomes of pulmonary venous isolation alone for persistent atrial fibrillation (PerAF) remain unclear. Adjuvant posterior wall isolation (PWI) has become a potential supplementary strategy for improving the outcome of PerAF ablation. This meta-analysis aimed to evaluate the effect of PWI added to catheter ablation for PerAF.

METHODS

PubMed, EMBASE, and Cochrane Library databases were searched for studies comparing the outcomes of PerAF ablation with and without PWI. The efficacy outcomes were recurrence of atrial arrhythmia (AA), atrial fibrillation (AF), and atrial tachycardia (AT), and the safety outcome was adverse events.

RESULTS

In total, 8 studies with 1428 patients were included in the pooled analyses. The results showed that PWI significantly reduced the recurrence of AA (RR = 0.69, 95% CI = 0.55-0.87, p = 0.002, I² = 63%) and AF (RR = 0.57, 95% CI = 0.40 - 0.80, p = 0.001, I² = 70%). AT recurrence (RR = 0.92, 95% CI = 0.67 - 1.27, p = 0.63, I² = 42%) and adverse events (RR = 1.11, 95% CI = 0.67-1.84, p = 0.70, I² = 0%) were comparable between the two groups. In the sub-analyses, the efficacy of PWI in reducing AA recurrence was consistent in patients who underwent cryoablation or debulking ablation.

CONCLUSION

PWI effectively decreased AA recurrence after PerAF ablation without increasing the risk of AT or procedure-related complications. However, more randomized studies are needed to confirm these results. This article is protected by copyright. All rights reserved.

Pathophysiology of Atypical Atrial Flutters

Atypical atrial flutters are complex supraventricular arrhythmias that share different pathophysiological aspects in common. In most cases, the arrhythmogenic substrate is essentially embodied by slow-conducting areas eliciting re-entrant circuits. Although atrial scarring seems to promote slow conduction, these arrhythmias may occur even in the absence of structural heart disease. To set out the ablation strategy in this setting, three-dimensional mapping systems have proved invaluable over the last decades, helping the cardiac electrophysiologist understand the electrophysiological complexity of these circuits and easily identify critical areas amenable to effective catheter ablation.

Efficacy and Safety of Radiofrequency Ablation of Thyroid Nodules: A Multi-institutional Prospective Cohort Study

BACKGROUND

Radiofrequency ablation (RFA) has been recently adopted into the practice of thyroidology in the United States, although its use as an alternative to traditional thyroid surgery in Asia and Europe came near the turn of the 21st century. In the United States, only a few studies with small sample sizes have been published to date. We examined outcomes of benign thyroid nodules treated with RFA from two North American institutions.

METHODOLOGY

We performed a prospective, multi-institutional cohort study of thyroid nodules treated with RFA between July 2019 and January 2022. Demographics, sonographic characteristics of thyroid nodules, thyroid function profiles, procedural details, complications, and nodule volume measurements at 1, 3, 6, and 12 months follow-up were evaluated. Adjusted multivariate logistic regression analysis was performed to identify sonographic features associated with treatment failure.

RESULTS

A total of 233 nodules were included. The median and interquartile range of volume reduction rate (VRR) at 1, 3, 6, and 12 months were 54% (IQR: 36%-73%), 58% (IQR: 37%-80%), 73% (IQR: 51%-90%), and 76% (IQR: 52%-90%), respectively (P<0.001). Four patients presented with toxic adenomas. All patients were confirmed euthyroid at 3-month post-procedure follow-up. Two patients developed temporary hoarseness of voice, but no hematoma or nodular rupture occurred post-procedure. Elastography was significantly associated with VRR. Compared to soft nodules, stiff nodules were more likely to have a lower VRR (OR: 11.64, 95%CI: 3.81-35.53, P<0.05), and mixed elasticity was also more likely to have a lower VRR (OR: 4.9; 95%CI: 1.62-14.85, P<0.05).

CONCLUSION

This is the largest multi-institutional North American study examining thyroid nodule treatment response to RFA. RFA is a safe and effective treatment option that allows preservation of thyroid function with minimal risk of procedural complications.

Procedural Feasibility and Long-Term Efficacy of Catheter Ablation of Atypical Atrial Flutters in a Wide Spectrum of Heart Diseases: An Updated Clinical Overview

Atypical atrial flutters (AAFL) are difficult-to-manage atrial arrhythmias, yet potentially amenable to effective radiofrequency catheter ablation (CA). However, data on CA feasibility are only sparingly reported in the literature in different clinical settings, such as AAFL related to surgical correction of congenital heart disease. The aim of this review was to provide an overview of the clinical settings in which AAFL may occur to help the cardiac electrophysiologist in the prediction of the tachycardia circuit location before CA. Moreover, the role and proper implementation of cutting-edge technologies in this setting were investigated as well as which procedural and clinical factors are associated with long-term failure to maintain sinus rhythm (SR) to find out which patients may, or may not, benefit from this procedure. Not only different surgical and non-surgical scenarios are associated with peculiar anatomical location of AAFL, but we also found that CA of AAFL is generally feasible. The success rate may be as low as 50% in surgically corrected congenital heart disease (CHD) patients but up to about 90% on average after pulmonary vein isolation (PVI) or in patients without structural heart disease. Over the years, the progressive implementation of three-dimensional mapping systems and high-density mapping tools has also proved helpful for ablation of these macro-reentrant circuits. However, the long-term maintenance of SR may still be suboptimal due to the progressive electroanatomic atrial remodeling occurring after cardiac surgery or other interventional procedures, thus limiting the likelihood of successful ablation in specific clinical settings.

Comparison of Cryoballoon and Contact Force-Sensing Radiofrequency Ablation for Persistent Atrial Fibrillation in Clinical Practice

BACKGROUND

Outcomes of cryoballoon ablation for persistent atrial fibrillation (AF) are unclear, especially in Japanese patients, so the effectiveness and safety of cryoballoon ablation in clinical practice were retrospectively compared with those of contact force-sensing radiofrequency (CFRF) ablation including the high-power protocol.

METHODS AND RESULTS

Consecutive patients with persistent AF were reviewed, and 253 and 265 patients who underwent cryoballoon and CFRF ablation, respectively, were enrolled. The primary endpoint was atrial arrhythmia recurrence. The secondary endpoints were periprocedural complications and repeat ablation. The rate of additional left atrial (LA) ablation after pulmonary vein isolation (PVI) was similar between groups (68.8% cryoballoon vs. 74.0% CFRF, P=0.19). Freedom from atrial arrhythmia recurrence was comparable between groups over a follow-up of 25.5±12.5 months (72.3% cryoballoon vs. 69.8% CFRF; adjusted hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.59-1.21, P=0.36). Outcomes were similar in the subgroups of PVI alone and PVI plus additional LA ablation. LA posterior wall isolation, absence of defragmentation, and low creatine clearance, but not catheter selection, were associated with the primary endpoint. Periprocedural complications (adjusted HR 0.73, 95% CI 0.34-1.54, P=0.41) and repeat ablation (adjusted HR 1.11, 95% CI 0.71-1.74, P=0.64) were similar for both procedures.

CONCLUSIONS

Cryoballoon ablation for persistent AF in Japanese clinical practice had acceptable outcomes comparable to those of advanced CFRF ablation.

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.

Procedural Safety and Efficacy for Pulmonary Vein Isolation with the Novel Polarx™ Cryoablation System: A Propensity Score Matched Comparison with the Arctic Front™ Cryoballoon in the Setting of Paroxysmal Atrial Fibrillation

Background

The novel Polarx™ cryoablation system is currently being studied for atrial fibrillation (AF) ablation. To the best of our knowledge, no study comparing the novel cryoablation system with the standard Arctic Front™ cryoballoon is available in today's literature. This study aims to compare Polarx™ and Arctic Front™ cryoballoon in terms of safety and efficacy.

Methods

From a total cohort of 202 patients who underwent pulmonary vein (PV) isolation for paroxysmal AF through cryoablation, a population of 30 patients who used Polarx™ were compared with 30 propensity-score matched patients who used Arctic Front™.

Results

Pulmonary vein occlusion and electrical isolation were achieved in all (100%) veins with a mean number of 1.09 ± 0.3 occlusion per vein using Polarx™ and 1.19 ± 0.5 occlusion per vein using Arctic Front™ (p = 0.6). Shorter procedure and fluoroscopy time were observed with Polarx™ group (60.5 ± 14.23 vs 73.43 ± 13.26 mins, p = 0.001; 12.83 ± 6.03 vs 17.23 ± 7.17 mins, p = 0.01, respectively). Lower cumulative freeze duration per vein was also observed with Polarx™ (203.38 ± 72.03 vs 224.9 ± 79.35 mins, p = 0.02). There was no significant difference in isolation time between the two groups (34.47 ± 21.23 vs 34.18 ± 26.79 secs, p = 0.9).

Conclusions

The novel Polarx™ cryoablation system showed similar efficacy in vein occlusion and isolation and safety profile when compared to Arctic Front™ cryoablation system. Procedure time, fluoroscopy time, and cumulative freeze duration were significantly lower with Polarx™ cryoablation system.

Second-generation cryoballoon versus contact force radiofrequency ablation for atrial fibrillation: an updated meta-analysis of evidence from randomized controlled trials

Catheter ablation has been recommended for patients with symptomatic atrial fibrillation (AF), with pulmonary vein isolation being the cornerstone of the ablation procedure. Newly developed technologies, such as cryoballoon ablation with a second-generation cryoballoon (CB2) and the contact force radiofrequency (CF-RF) ablation, have been introduced in recent years to overcome the shortcomings of the widely used RF ablation approach. However, high-quality results comparing CB2 and CF-RF remain controversial. Thus, we conducted this meta-analysis to assess the efficacy and safety between CB2 and CF-RF using evidence from randomized controlled trials (RCTs). Databases including Embase, PubMed, the Cochrane Library, and ClinicalTrials.gov were systematically searched from their date of inception to January 2021. Only RCTs that met the inclusion criteria were included for analysis. The primary outcome of interest was freedom from atrial tachyarrhythmia (AT) during follow-up. Secondary outcomes included procedure-related complications, procedure time and fluoroscopy time. Six RCTs with a total of 987 patients were finally enrolled. No significant differences were found between CB2 and CF-RF in terms of freedom from AT (relative risk [RR] = 1.03, 95% confidence interval [CI] 0.92-1.14, p = 0.616) or total procedural-related complications (RR = 1.25, 95% CI 0.69-2.27, p = 0.457). CB2 treatment was associated with a significantly higher risk of phrenic nerve palsy (PNP) than CF-RF (RR = 4.93, 95% CI 1.12-21.73, p = 0.035). The occurrences of pericardial effusion/tamponade and vascular complications were comparable between the CB2 and CF-RF treatments (RR = 0.41, p = 0.398; RR = 0.82, p = 0.632). In addition, CB2 treatment had a significantly shorter procedure time than CF-RF (weighted mean difference [WMD] = - 20.75 min, 95% CI - 25.44 ~ - 16.05 min, P < 0.001), whereas no difference was found in terms of fluoroscopy time (WMD = 4.63 min, p = 0.179). CB2 and CF-RF treatment are comparable for AF patients regarding freedom from AT and procedure-related complications. Compared to CF-RF, CB2 treatment was associated with a shorter procedure time but a higher incidence of PNP. Further large-scale studies are warranted to compare these two techniques and provide an up-to-date recommendation.

Single procedural outcomes in the setting of percutaneous ablation for persistent atrial fibrillation: a propensity-matched score comparison between different strategies

BACKGROUND

Catheter ablation for persistent atrial fibrillation (persAF) is associated with less favorable outcomes than for paroxysmal AF. To improve success rates, left atrial (LA) substrate modification is frequently performed in addition to pulmonary vein isolation (PVI). The purpose of the study was to compare 4 different ablation approaches using radiofrequency catheter ablation (RFCA) or cryoballoon ablation (CB-A) for persAF and to evaluate the respective outcomes on a midterm follow-up of 12 months.

METHODS

We did a propensity score-matched comparison of 30 patients undergoing PVI + LA posterior wall isolation (LAPWI) with CB-A, 30 patients who underwent PVI + linear ablation (roof and mitral lines) using RFCA, 60 patients with PVI alone using CB-A, and 60 patients who had PVI alone using RFCA. The endpoint was recurrence of documented atrial tachyarrhythmias (ATas) > 30 s at 1-year follow-up.

RESULTS

After 12 months, freedom from ATas after a single procedure was 83.3% in the PVI + LAPWI group, 46.7% in the PVI + linear ablation group, 58.3% in the PVI-alone CB-A group, and 61.6% PVI-alone RFCA (p = 0.03). Moreover, freedom from ATas was significantly higher comparing the PVI + LAPWI group with each of the other groups.

CONCLUSIONS

In this propensity-matched comparison of strategies for persAF, LAPW ablation in addition to PVI with CB-A seems to improve 1-year outcome in comparison to PVI + linear ablation using RFCA and to PVI alone using RFCA or CB-A. Randomized comparisons are eagerly awaited.

[Success rate of one-stop procedure for atrial fibrillation ablation and its impact on cardiac function: a propensity-matched study]

OBJECTIVE

To investigate the effect of the combination of atrial fibrillation (AF) ablation and left atrial appendage closure (LAAC) on cardiac function and the success rate of AF ablation.

METHODS

We retrospectively analyzed the data of 56 patients with AF undergoing a one-stop procedure for AF ablation and LAAC in our hospital between May, 2015 and May, 2019. Propensity score matching (PSM) at the ratio of 1:1 was used to select 56 control patients undergoing AF ablation at high risk of stroke, for matching with the hybrid procedure group. The perioperative complications, thromboembolic events, recurrence of atrial arrhythmia and cardiac function were compared between the groups.

RESULTS

The two groups of patients were comparable for age, gender, BMI, duration and type of AF, concomitant diseases, CHA2DS2-VASc and HAS-BLED scores (P > 0.05). The incidence of complications did not differ significantly between the hybrid procedure group and AF ablation group (17.9% vs 12.5%, P=0.430). Compared with the control patients with AF ablation alone, the patients undergoing the hybrid procedure had a lowered incidence of thromboembolic events, but the difference was not statistically significant (1.8%vs 3.6%, P=1.000). The hybrid procedure did not improve the success rate of AF ablation (OR: 1.338, 95%CI: 0.451-3.973, P= 0.600) but significantly improved the cardiac function parameters including NT-pro BNP (945.3±1401.6 pg/mL vs 1520.7±2089.1 pg/mL, P=0.010), LVEF[(60.8±7.0)% vs (58.6±7.8)%, P=0.044], and left atrial diameter (43.9±7.5 mm vs 45.6±6.3 mm, P=0.076); but the improvement of cardiac function was more obvious in the control patients undergoing AF ablation alone (P < 0.039).

CONCLUSIONS

The combination of AF ablation and LAAC is safe but does not improve the success rate of AF ablation. The one-stop procedure can improve cardiac function of the patients, but AF ablation alone can achieve better improvement of cardiac function.

Voltage-guided ablation in persistent atrial fibrillation-favorable 1-year outcome and predictors

INTRODUCTION

Pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF) has a low success rate. A newer ablation concept targets left atrial (LA) low voltage zones (LVZ) which correlate with fibrosis and predict recurrence after PVI. We aimed to determine the success of combined PVI- and LVZ-guided ablation and to identify the predictors for LVZ and for ablation success.

METHODS AND RESULTS

A total of 119 consecutive patients who underwent their first ablation procedure due to persistent AF were included. After acquisition of a high-resolution LA voltage map, PVI- and LVZ-guided ablation were performed. Mean age was 69 ± 8 years, 53% were men, and 8% had longstanding persistent AF. We found LVZ in 55% of patients. Twelve-month freedom from recurrences off drugs was 69%. The only independent predictor for recurrence was the existence of LVZ (OR 4.2, 95% CI 1.54-11.41, p = 0.005). Existence of LVZ was predicted positively by age ≥ 67 years (OR 4.4, 95% CI 1.4-13.7, p = 0.011), LA volume index ≥ 68 ml/m² (OR 3.9, 95% CI 1.4-10.5, p = 0.008), and GFR ≤ 85 ml/min/1.73 m² (OR 12.5, 95% CI 2.0-76.6, p = 0.006). BMI ≥ 26 kg/m² (OR 0.06, 95% CI 0.01-0.30, p = 0.001) was a negative predictor of LVZ.

CONCLUSION

LVZ-guided ablation in combination with PVI results in comparably high success rates. However, the existence of LVZ remains the strongest predictor of ablation success.

Comparative efficacy and safety of catheter ablation interventions for atrial fibrillation: comprehensive network meta-analysis of randomized controlled trials

PURPOSE

Point-by-point radiofrequency (RF) ablation has been the cornerstone of pulmonary vein isolation (PVI) for patients with atrial fibrillation (AF); however, it remains a complex and time-consuming procedure. Many novel AF catheter ablation (CA) techniques have been introduced, but whether they represent valuable alternatives remains controversial. Thus, we conducted a network meta-analysis to comprehensively evaluate the efficacy and safety of different CA interventions.

METHODS

We systematically searched several databases (Embase, PubMed, the Cochrane Library, and ClinicalTrials.gov ) from inception to March, 2020. The primary outcomes of interest were freedom from atrial tachyarrhythmia (AT) and procedure-related complications; secondary outcomes included procedure time and fluoroscopy time.

RESULTS

Finally, 33 randomized controlled trials (RCTs) with a total of 4801 patients were enrolled. No significant differences were found among the different interventions in terms of primary efficacy or safety outcomes. PVAC was most likely to have the shortest procedure time (Prbest = 61.5%) and nMARQ the shortest fluoroscopy time (Prbest = 60.6%); compared with conventional irrigated RF (IRF) ablation, cryoballoon ablation (CBA) showed comparable clinical efficacy and safety; CBA with second-generation CB (CB2) had a significantly shorter procedure time than IRF with contact force technology (CF-IRF) (WMD = - 20.75; p = 0.00).

CONCLUSION

There is insufficient evidence to suggest that one CA technique is superior to another. However, PVAC may be associated with a shorter procedural duration, and the CB2 catheters also seemed to reduce the procedure time compared with that of CF-IRF. Further large-scale studies are warranted to compare the available CA techniques and provide an up-to-date optimum recommendation.

A systematic review and meta-analysis comparing second-generation cryoballoon and contact force radiofrequency ablation for initial ablation of paroxysmal and persistent atrial fibrillation

INTRODUCTION

Cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the preferred modalities for catheter ablation of atrial fibrillation (AF). Technological advances have improved procedural outcomes, warranting an updated comparison. We sought to evaluate the efficacy and safety of CBA-2nd generation (CBA-2G) in comparison to RFA-contact force (RFA-CF) in patients with AF.

METHODS

MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched until 03/01/2020 for relevant studies comparing CBA-2G versus RFA-CF in patients undergoing initial catheter ablation for AF.

RESULTS

A total of 17 studies, involving 11 793 patients were included. There was no difference between the two groups in the outcomes of freedom from atrial arrhythmia (p = .67) and total procedural complications (p = .65). There was a higher incidence of phrenic nerve palsy in CBA-2G (odds ratio: 10.7; 95% confidence interval [CI]: 5.85 to 19.55; p < .001). Procedure duration was shorter (mean difference: -31.32 min; 95% CI: -40.73 to -21.92; p < .001) and fluoroscopy duration was longer (+3.21 min; 95% CI: 1.09 to 5.33; p = .003) in CBA-2G compared to RFA-CF. In the subgroup analyses of patients with persistent AF and >1 freeze lesion delivered per vein, there was no difference in freedom from atrial arrhythmia.

CONCLUSIONS

In AF patients undergoing initial ablation, CBA-2G and RFA-CF were equally efficacious. The procedure duration was shorter, but with a higher incidence of phrenic nerve palsy in CBA-2G. In patients with persistent AF, there was no difference in the efficacy between CBA-2G or RFA-CF techniques.

Clinical outcome of pulmonary vein isolation alone ablation strategy using VISITAG SURPOINT in nonparoxysmal atrial fibrillation

BACKGROUND

Recent studies have shown the improvement in long-term effectiveness with standardized pulmonary vein isolation (PVI) aimed at creating durable and contiguous lesions with VISITAG SURPOINT (VS) in paroxysmal atrial fibrillation (PAF).

OBJECTIVE

We aimed to assess efficacy of PVI alone strategy using VS in non-PAF patients and evaluate factors associated with corresponding clinical outcomes.

METHODS

Consecutive patients who underwent PVI for persistent/long-standing persistent AF between May 2017 to July 2019 were studied retrospectively. PVI was performed with 30-50 W guided by VS (posterior target: 400-500, anterior target: 500). Left atrial voltage maps were created during atrial pacing after PVI.

RESULTS

A total of 140 patients (119 males, age 62 ± 10 years, long-standing persistent AF: 35) were included and followed for median of 454 days. No adverse events were reported in any patients during periprocedural and follow-up period of up to 28 months. Kaplan-Meier analysis estimated that freedom from atrial tachycardia or AF (AT/AF) without antiarrhythmics at 1-year was 70%. Radiofrequency delivery with higher power was associated with increased first-pass isolation rate, but not with freedom from AT/AF. In multivariate analysis, long-standing persistent AF and % low-voltage zone (%LVZ) were independent predictors of clinical outcome. The best cut-off value of %LVZ for predicting AT/AF recurrence was 3.24%. Freedom from AT/AF was 88% in patients with persistent AF and %LVZ < 3.24%, while 27% in those with long-standing persistent AF and %LVZ ≥ 3.24%.

CONCLUSIONS

PVI alone using VS was associated with excellent 1-year success in patients with persistent AF and %LVZ < 3.24%, but was insufficient in those with long-standing persistent AF and/or %LVZ ≥ 3.24%.

Lesion characteristics between cryoballoon ablation and radiofrequency ablation with a contact force-sensing catheter: Late-gadolinium enhancement magnetic resonance imaging assessment

BACKGROUND

Pulmonary vein isolation (PVI) lesions after cryoballoon ablation (CBA) are characterized as a wider and more continuous than that after conventional radiofrequency catheter ablation (RFCA) without the contact force (CF)-sensing technology. However, the impact on the lesion characteristics of ablation with a CF-sensing catheter has not been well discussed. We sought to assess the lesions using late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) and to compare the differences between the two groups (CB group vs. RF group).

METHODS

A total of 30 consecutive patients who underwent PVI were enrolled (CB group, 18; RF group, 12). The RF applications were delivered with a target lesion size index (LSI) of 5. The PVI lesions were assessed by LGE-MRI 3 months after the PVI. The region around the PV was divided into eight segments: roof, anterior-superior, anterior carina, anterior inferior, bottom, posterior inferior, posterior carina, and posterior superior segment. The lesion width and visual gap of each segment were compared between the two groups. The visual gaps were defined as no-enhancement site of >4 mm.

RESULTS

The mean LSI was 4.7 ± 0.7. The lesion width was significantly wider but the visual gaps were more frequently documented at the bottom segment of right PV in the CBA group (lesion width: 8.1 ± 2.2 vs. 6.3 ± 2.2 mm; p = .032; visual gap at the bottom segment or right PV: 39% vs. 0%; p = .016).

CONCLUSIONS

The PVI lesion was wider after CBA, while the visual gaps were fewer after RFCA with a CF-sensing catheter.

Real-world safety of catheter ablation for atrial fibrillation with contact force or cryoballoon ablation

Purpose

Real-world data can help medical administrators, physicians, and payers make evidence-based decisions regarding treatment choices. The objective of this study was to compare real-world safety outcomes with the latest catheter technologies used for the treatment of atrial fibrillation (AF).

Methods

The Vizient Health Systems database, a large US hospital database, was used to compare acute complications in AF ablation with the contact force sensing THERMOCOOL SMARTTOUCH® Catheter or the THERMOCOOL SMARTTOUCH® SF Catheter (ST) versus the second-generation Arctic Front Advance™ Cryoablation Catheter (CB2) between September 2015 and June 2017. The primary outcome was a composite safety endpoint of acute ablation-related complications defined via ICD-10 diagnosis and procedure codes, including tamponade and other pericardial events, respiratory complications, stroke, cerebral or pre-cerebral occlusion/stenosis without infarction, vascular access complications, hemorrhage, phrenic nerve injury, myocardial infarction, and pulmonary embolism.

Results

In total, 1473 ablations met all inclusion criteria (407 ST, 1066 CB2). Ablations for paroxysmal AF (PAF) had a lower complication rate than ablations for persistent AF (PsAF) (6.1% vs. 7.3%), as did ablations with ST compared with CB2 within each AF type (PAF 6.0% vs. 6.1%, PsAF 6.3% vs. 7.8%). Neither ablation catheter nor AF type was statistically significant after controlling for site volume, patient age, and comorbid conditions (ST vs. CB2: OR 0.86, p = 0.5544; PsAF vs. PAF: OR 1.08, p = 0.7376).

Conclusion

Acute ablation-related complication rates were low and were not significantly associated with catheter technology. Increased risk of complication was attributable to low-volume sites and baseline patient characteristics.

Meta-Analysis Comparing Cryoballoon Versus Radiofrequency as First Ablation Procedure for Atrial Fibrillation

Pulmonary vein isolation is the cornerstone of atrial fibrillation (AF) ablation. Radiofrequency (RF) represents a standard of care for pulmonary vein isolation, whereas cryoballoon (CB) ablation has emerged as a valid alternative. The aim of our meta-analysis was to explore the efficacy and safety of CB compared with RF as first ablation procedure for AF. We searched the literature for studies that investigated this issue. The primary efficacy outcome was AF recurrence. The safety outcomes were: pericardial effusion, cardiac tamponade, phrenic nerve palsy, vascular complications, and major bleedings. Fourteen randomized controlled studies and 34 observational studies were included in the analysis. A total of 7,951 patients underwent CB ablation, whereas 9,641 received RF ablation. Mean follow-up was 14 ± 7 months. Overall, CB reduced the incidence of AF recurrence compared with RF ablation (relative risk [RR] 0.86; 95% confidence interval [CI] 0.78 to 0.94; p = 0.001), and this result was consistent across different study design and AF type. CB had a significantly higher rate of phrenic nerve palsy, whereas it was related to a lower incidence of pericardial effusion, cardiac tamponade (RR 0.58; 95% CI 0.38 to 0.88; p = 0.011) and vascular complications (RR 0.61; 95% CI 0.48 to 0.77; p <0.001) compared with RF. There was no significant difference in major bleedings between the 2 strategies. CB ablation had a shorter procedural time compared with RF (mean difference -20.76 minutes; p <0.001). In conclusion, considered its efficacy/safety profile and short procedural time, CB ablation represents the preferable option for first AF ablation procedure.

Reducing radiation exposure in second-generation cryoballoon ablation without compromising clinical outcome

Purpose

Pulmonary vein isolation (PVI) using cryoballoon (CB) ablation is associated with an increased radiation exposure compared with radiofrequency ablation. Previous studies showed that radiation exposure in CB PVI can be reduced by optimizing the fluoroscopy protocol without comprising acute efficacy and safety. We evaluated the mid-term outcome of a modified fluoroscopy protocol in patients undergoing CB PVI.

Methods

The study population comprised 90 consecutive patients who underwent second-generation CB-based PVI. The first 46 patients underwent CB PVI with conventional fluoroscopy settings (group A, historic control group). In the following 44 patients (group B), a modified fluoroscopy protocol was applied consisting of (1) visualization of degree of PV occlusion only by fluoroscopy (no cine runs); (2) increased radiation awareness. Primary endpoints were the total dose area product (DAP), fluoroscopy time, and freedom from documented recurrence of atrial fibrillation (AF) after a single procedure.

Results

Group B had a lower median DAP (1393 cGycm² vs. 3232 cGycm², P < 0.001) and median fluoroscopy time (20 min vs. 24 min, P < 0.001) as compared with group A. The 1-year freedom from documented recurrence of AF after a single procedure was similar among groups (74% in group A vs. 77% in group B, P = 0.71). There were no significant differences between both groups for the secondary endpoints, including procedure duration, proportion of patients with complete electrical isolation, and complications.

Conclusion

Using a modified fluoroscopy protocol and increased radiation awareness, radiation exposure can be significantly reduced in CB PVI with a similar 1-year clinical outcome.

Comparing between second-generation cryoballoon vs open-irrigated radiofrequency ablation in elderly patients: Acute and long-term outcomes

Background

Limited comparative data are available regarding catheter ablation (CA) of atrial fibrillation (AF) using second‐generation cryoballoon (CB‐2) vs radiofrequency (RF) ablation in elderly patients (>75‐year‐old).

Hypothesis

CB‐2 ablation may demonstrate different outcomes compared with that using RF ablation for elderly patients with AF.

Method

Elderly patients with symptomatic drug‐refractory AF were included in the study. Pulmonary vein isolation was performed in all patients.

Results

A total of 324 elderly patients were included (RF: 176, CB‐2:148) from September 2016 to April 2019. The CB‐2 was associated with shorter procedure time and left atrial dwell time (112.9 ± 11.1 vs 135.1 ± 9.9 minutes, P < .001; 53.7 ± 8.9 vs 65.1.9 ± 9.0 minutes, P < .001), but marked fluoroscopy utilization (22.1 ± 3.3 vs 18.5 ± 3.6 minutes, P < .001). Complications occurred in 3.3% (CB‐2) and 6.2% (RF) of patients with no significant different (P = .307). The length of stay after ablation was shorter, but the costs were higher in the CB‐2 group (1.94 vs 2.53 days, P < .001 and 91 132.6 ± 3723.5 vs 81 149.4 ± 6824.1 CNY, P < .001) compared to the RF group. Additionally, the rate of early recurrence of atrial arrhythmia was lower in the CB‐2 group (14.2 vs 23.3%, P = .047), but the long‐term success rate was similar between two groups.

Conclusions

CB‐2 is associated with shorter procedure time, left atrial dwell time, and length of stay after ablation, but its costs and fluoroscopy time are greater than the RF group. Moreover, the rate of complications and long‐term success are similar between the two groups.

Costs and long-term outcomes following pulmonary vein isolation for atrial fibrillation in elderly patients using second-generation cryoballoon vs. open-irrigated radiofrequency in China

Purpose

Limited comparative data are available regarding catheter ablation (CA) of atrial fibrillation (AF) using second-generation cryoballoon (CB-2) vs. radiofrequency (RF) ablation in elderly patients (> 75 years old). The present study aimed to compare the costs and clinical outcomes in elderly patients using these two strategies.

Methods

Elderly patients with symptomatic drug-refractory paroxysmal/short-lasting persistent AF were included in the study. Pulmonary vein isolation (PVI) was performed in all patients.

Results

A total of 324 elderly patients were included (RF,176; CB-2,148) from September 2016 to April 2019. The CB-2 was associated with shorter procedure time and left atrial dwell time (112.9 ± 11.1 vs. 135.1 ± 9.9 min, P < 0.001; 53.7 ± 8.9 vs. 65.1.9 ± 9.0 min, P < 0.001) but marked fluoroscopy utilization (22.1 ± 3.3 vs. 18.5 ± 3.6 min, P < 0.001). Complications occurred in 3.3% (CB-2) and 6.2% (RF) of patients with no significant different (p = 0.307). The length of stay after ablation was shorter, but the costs were higher in the CB-2 group (1.94 vs. 2.53 days, P < 0.001 and 91,132.6 ± 3723.5 vs. 81,149.4 ± 6824.1 CNY, P < 0.001) compared to the RF group. Additionally, the rate of early recurrence of atrial arrhythmia (ERAA) was lower in the CB-2 group (14.2 vs. 23.3%, P = 0.047), but the long-term success rate was similar between two groups.

Conclusions

CB-2 is associated with shorter procedure time, left atrial dwell time, and length of stay after ablation, as well as lower ERAA, but its costs and fluoroscopy time are greater than the RF group. Moreover, the rate of complications and long-term success is similar between the two groups.

Cryoballoon or Radiofrequency Ablation for Atrial Fibrillation Assessed by Continuous Monitoring: A Randomized Clinical Trial

BACKGROUND

Advanced generation ablation technologies have been developed to achieve more effective pulmonary vein isolation (PVI) and minimize arrhythmia recurrence after atrial fibrillation (AF) ablation.

METHODS

We randomly assigned 346 patients with drug-refractory paroxysmal AF to contact force-guided radiofrequency ablation (CF-RF; n=115), 4-minute cryoballoon ablation (Cryo-4; n=115), or 2-minute cryoballoon ablation (Cryo-2; n=116). Follow-up was 12 months. The primary outcome was time to first documented recurrence of symptomatic or asymptomatic atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia) between days 91 and 365 after ablation or a repeat ablation procedure at any time. Secondary end points included freedom from symptomatic arrhythmia and AF burden. All patients received an implantable loop recorder.

RESULTS

One-year freedom from atrial tachyarrhythmia defined by continuous rhythm monitoring was 53.9%, 52.2%, and 51.7% with CF-RF, Cryo-4, and Cryo-2, respectively (P=0.87). One-year freedom from symptomatic atrial tachyarrhythmia defined by continuous rhythm monitoring was 79.1%, 78.2%, and 73.3% with CF-RF, Cryo-4, and Cryo-2, respectively (P=0.26). Compared with the monitoring period before ablation, AF burden was reduced by a median of 99.3% (interquartile range, 67.8%-100.0%) with CF-RF, 99.9% (interquartile range, 65.3%-100.0%) with Cryo-4, and 98.4% (interquartile range, 56.2%-100.0%) with Cryo-2 (P=0.36). Serious adverse events occurred in 3 patients (2.6%) in the CF-RF group, 6 patients (5.3%) in the Cryo-4 group, and 7 patients (6.0%) in the Cryo-2 group, with no significant difference between groups (P=0.24). The CF-RF group had a significantly longer procedure duration but significantly shorter fluoroscopy exposure (P<0.001 vs cryoballoon groups).

CONCLUSIONS

In this multicenter, randomized, single-blinded trial, CF-RF and 2 different regimens of cryoballoon ablation resulted in no difference in 1-year efficacy, which was 53% by time to first recurrence but >98% burden reduction as assessed by continuous cardiac rhythm monitoring.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01913522.

The industrialization of ablation: a highly standardized and reproducible workflow for radiofrequency ablation of atrial fibrillation

BACKGROUND OR PURPOSE

The purpose of this analysis was to report on efficacy of a standardized workflow for atrial fibrillation (AF) ablation using technology advances such as 3D imaging and contact force sensing in a real-world setting.

METHODS

Consecutive AF ablations from 2014 to 2015 at a high-volume site in Belgium were included. The workflow consisted of a pre-specified procedure sequence including 3D modeling followed by radiofrequency encircling of the pulmonary veins (25 W posterior wall, 35 W anterior wall) with a THERMOCOOL SMARTTOUCH® Catheter guided by CARTO VISITAG™ Module (2.5 mm/5 s stability, 50% > 7 g) and ablation index (targets: 550 anterior wall, 400 posterior wall). Efficiency endpoints were procedure time, fluoroscopy time, and radiation dose. The primary effectiveness endpoint was freedom from atrial arrhythmia recurrence.

RESULTS

A total of 605 paroxysmal AF (PAF) and 182 persistent AF (PsAF) patients were followed for 436 ± 199 days. Mean procedure times were short (PAF: 96.1 ± 26.2 min; PsAF: 109.2 ± 35.6 min) with most procedures (90.6% PAF; 81.3% PsAF) completed in ≤ 120 min. Minimal fluoroscopy was utilized (PAF: 6.1 ± 3.8 min, 5.9 ± 3.4 Gy*cm²; PsAF: 6.9 ± 4.7 min, 7.4 ± 4.9 Gy*cm²). Freedom from atrial arrhythmia recurrence was higher for PAF than PsAF patients (OR: 2.0, 95% CI: 1.4-2.9, p = 0.0003), but adjusted mean rates were high in both groups (81.0% vs. 67.9%). Rates were adjusted for prior ablation and age (at 65 years).

CONCLUSION

AF ablation using a standardized workflow resulted in low procedure times and variability, with minimal fluoroscopy exposure. Long-term freedom from atrial arrhythmia recurrence was high in both PAF and PsAF populations.

Cryoballoon Ablation in Patients With Paroxysmal Atrial Fibrillation: An Evaluation of Cohorts With and Without Structural Heart Disease

BACKGROUND

Pulmonary vein isolation (PVI) is the most widely adopted strategy for paroxysmal atrial fibrillation (PAF) ablation. Limited evidence on acute results and late outcomes of cryoballoon (CB)-PVI in patients with structural heart disease (SHD) exist. The aim of this analysis was to compare acute procedural results and the 1-year recurrence rate of a single CB-PVI procedure in a PAF population with and without SHD.

METHOD

From April 2012 to May 2017, a total of 2,031 patients with AF underwent CB-PVI and were followed prospectively in the framework of the One Shot TO Pulmonary vein isolation (1STOP) ClinicalService project, involving 36 Italian cardiology centres. We identified patients with SHD according to criteria proposed by current ESC guidelines: left ventricular (LV) systolic or diastolic dysfunction, long-standing hypertension with LV hypertrophy, and/or other structural heart disease. Data on procedural outcomes and long-term freedom from AF recurrence were evaluated.

RESULTS

Our population consisted of 1,452 patients, of whom 282 (19.4%) were classified as having SHD. Compared to non-SHD patients, the SHD cohort was older (mean ± standard deviation, 62.9 ± 9.0 vs 58.2 ± 11.4 years; p < 0.001), was more frequently male (79.1% vs 69.8%; p < 0.002), had a higher thrombo-embolic risk (CHA₂DS₂VASc ≥2: 63.4% vs 40.2%; p < 0.001), had a higher body mass index (27.7 ± 3.9 vs 26.4 ± 3.9 kg/m²; p < 0.001), had a larger atrial diameter (43.8 ± 7.0 vs 40.2 ± 5.8 mm; p < 0.001), and had a lower LV ejection fraction (57.2 ± 7.7% vs 60.7 ± 6.0%; p < 0.001). At the time of ablation, 73% of patients were on class Ic or III anti-arrhythmic drugs. Procedure time (106.9 ± 41.5 vs 112.1 ± 46.8 min; p = 0.248), fluoroscopic time (28.7 ± 14.7 vs 28.6 ± 15.2 min; p = 0.819), and complication rate (3.9% vs 4.8%; p = 0.525) were not different between the SHD and non-SHD cohorts. However, the acute success rate (98.9% vs 97.7%; p = 0.016) was higher in patients with SHD. After a follow-up of 13.4 ± 12.8 months, freedom from symptomatic recurrence was 78.0% for SHD and 78.4% for non-SHD (p = 0.895). Recurrence rate was not related to either left atrial size or LVEF. In the SHD cohort, Class Ic or III anti-arrhythmic drugs treatment decreased from 70.7% of patients before ablation to 28.7% of patients after CB-PVI (p = 0.001).

CONCLUSIONS

CB-PVI was extensively applied to treat patients with PAF. Unlike previous PVI experiences, the acute success and recurrence rate after a single procedure was not related to the presence of SHD or to the degree of cardiac remodelling. Further studies are required to define whether CB-PVI has a useful role in patients with a significantly reduced ejection fraction as those patients were under-represented in the current population.

Left Atrial Volume Index Predicts Arrhythmia-Free Survival in Patients with Persistent Atrial Fibrillation Undergoing Cryoballoon Ablation

Background

Pulmonary vein isolation (PVI) using cryoballoon ablation (PVI-C) is increasingly performed as a first-line strategy for the treatment of patients with persistent atrial fibrillation (PersAF); however, follow-up data and predictors of procedural success are lacking.

Objective

To study the efficacy of PVI-C in patients with PersAF, focusing on predictors of procedural success.

Methods

By retrospective review, 148 consecutive patients with PersAF who underwent PVI-C were analyzed. The impact of several variables on outcome was evaluated in univariate and multivariate analyses and Cox proportional hazards regression models.

Results

After a mean follow-up of 19.2±10.9 months, 75 (50.7%) patients remained arrhythmia-free without the need for antiarrhythmic drug therapy. Patients with a normal left atrial volume index (LAVI) achieved a 71.0% arrhythmia-free survival. LAVI was the most powerful predictor of procedural success.

Conclusions

Arrhythmia-free survival after PVI-C in select patients with PersAF are promising. Moreover, LAVI is a valuable measurement to help guide ablation strategy and predict outcome when using cryoballoon ablation.

Recent advances in cryoballoon ablation for atrial fibrillation

Introduction: Pulmonary vein isolation (PVI), by catheter ablation, represents the current treatment for drug-resistant atrial fibrillation (AF). Nowadays cryoballoon (CB) is a recognized ablation method in patients with atrial fibrillation, mainly due to its ease of use, leading to reproducible and fast procedures. This novel single shot technology literally revolutionized the approach to AF ablation. Areas covered: The historical development of the cryoballoon, ablation techniques and new approaches beyond the ordinary PVI and complications are summarized here. Expert opinion: Although cryoballoon ablation has greatly standardized the approach to PVI a few critical points still need to be clarified scientifically in order to further uniform this procedure in cath labs worldwide. Duration and dosage of the cryoapplication is undoubtedly a topic of great interest.

Sex-specific efficacy and safety of cryoballoon versus radiofrequency ablation for atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is a growing healthcare burden, for which pulmonary vein isolation (PVI) using cryoballoon (CB) or radiofrequency (RF) represent attractive therapies. Women are at higher risk of recurrence after AF ablation and present a specific complications profile. Therefore, a systematic catheter-specific assessment of pulmonary vein isolation is urgently needed in women.

OBJECTIVE

Systematically assessing the sex-specific efficacy/safety of CB vs RF ablation.

METHODS

We performed a structured database search of the scientific literature for randomized controlled trials (RCTs) and observational prospective studies (OPS) comparing CB and RF ablation efficacy at 1 year. We investigated the reporting of sex-specific analyses and assessed the comparative sex-specific efficacy, safety and procedural characteristics of CB vs RF using random-effect meta-regression accounting for the proportion of enrolled women.

RESULTS

Twenty-three studies were included (18 OPS and 5 RCTs) for a total of 13 509 patients. Sex-specific outcomes by ablation device were reported in two and sex-specific regression in four studies, none of which took the ablation device into account. Meta-regression accounting for the proportion of enrolled women showed no significant difference in outcomes between RF or CB.

CONCLUSION

The sex-specific reporting in trials comparing CB to RF is extremely low. A quantitative meta-regression using the percentage of enrolled women as sex-specific indicator did not show any difference between CB and RF but acknowledging the low percentage of enrolled women and the lack of sex-specific data, further research including patient-level data is urgently needed to draw more definitive conclusions.

Cryoballoon Ablation for the Treatment of Atrial Fibrillation: A Meta-analysis

BACKGROUND

Ablation therapy is the treatment of choice in antiarrhythmic drugrefractory atrial fibrillation (AF). It is performed by either cryoballoon ablation (CBA) or radiofrequency ablation. CBA is gaining popularity due to simplicity with similar efficacy and complication rate compared with RFA. In this meta-analysis, we compare the recurrence rate of AF and the complications from CBA versus RFA for the treatment of AF.

METHODS

We systematically searched PubMed for the articles that compared the outcome of interest. The primary outcome was to compare the recurrence rate of AF between CBA and RFA. We also included subgroup analysis with complications of pericardial effusion, phrenic nerve palsy and cerebral microemboli following ablation therapy.

RESULTS

A total of 24 studies with 3527 patients met our predefined inclusion criteria. Recurrence of AF after CBA or RFA was similar in both groups (RR: 0.84; 95% CI: 0.65, 1.07; I2=48%, Cochrane p=0.16). In subgroup analysis, heterogeneity was less in paroxysmal AF (I2=0%, Cochrane p=0.46) compared to mixed AF (I2=72%, Cochrane p=0.003). Procedure and fluoroscopy time was less by 26.37 and 5.94 minutes respectively in CBA compared to RFA. Complications, pericardial effusion, and silent cerebral microemboli, were not different between the two groups, however, phrenic nerve palsy was exclusively present only in CBA group.

CONCLUSION

This study confirms that the effectiveness of CBA is similar to RFA in the treatment of AF with the added advantages of shorter procedure and fluoroscopy times.

Clinical significance of early recurrence of atrial fibrillation after cryoballoon vs. radiofrequency ablation-A propensity score matched analysis

Objectives

One of the mechanisms of early recurrence of atrial fibrillation (ERAF) after AF ablation is considered to be the inflammatory reaction of the atrial tissue. The aim of this study is to compare the clinical significance of ERAF at each stage for true AF recurrence between cryoballoon (CB) and radiofrequency (RF) ablation.

Methods

Among 798 paroxysmal AF patients who underwent an initial ablation, 460 patients (CB, n = 230; RF, n = 230) were selected by propensity score matching. Very ERAF (VERAF), ERAF-1M, ERAF-3M and true AF recurrence were defined as AF recurrence at 0–2, 3–30, 31–90 days and more than 90 days after the procedure, respectively.

Results

The patient characteristics of the two groups were similar. ERAF was observed 21% and 27% in the CB and RF groups, respectively. In both the CB and RF group, VERAF, ERAF-1M and ERAF-3M were more frequently observed in patients with true AF recurrence than in those without. In a multivariable analysis, ERAF-1M and ERAF-3M were found to be independent predictors of true AF recurrence in both the CB (P = 0.04 and P<0.001, respectively) and RF groups (P = 0.02 and P = 0.001, respectively). However, while VERAF was associated with true AF recurrence after RF ablation (P = 0.03), it was not associated with true AF recurrence after CB ablation (P = 0.19).

Conclusion

The relationship between ERAF and true AF recurrence differed between the RF and CB ablation groups. While VERAF was associated with true AF recurrence after RF ablation, it was not a predictor of true AF recurrence after CB ablation.

Cryoballoon ablation for persistent atrial fibrillation in patients without left atrial fibrosis

INTRODUCTION

The role of cryoballoon (CB) pulmonary vein isolation (PVI) for patients with persistent atrial fibrillation (AF) is controversial, since long-term success can be poor. We performed left atrial voltage mapping before CB PVI and determined AF-free survival depending on the extent of low-voltage areas (LVAs).

METHODS AND RESULTS

We consecutively enrolled 60 patients with persistent AF (average age, 60.6 ± 12.9 years; CHA₂ DS ₂ VASc score, 2.3 ± 1.6; and left atrial size 46.0 ± 5.2 mm) who were planned for CB PVI. Before ablation, we performed left atrial voltage mapping (Abbott EnSite Precision or Velocity). LVAs were defined if local bipolar signal amplitudes were less than 0.5 mV during sinus rhythm. Thirty-seven patients did not show significant LVAs (<10%), while 12 patients had LVAs between 10% and 30% and 11 patients showed substantial LVAs greater than 30% of the left atrial area. CB PVI could be successfully performed in all patients. A 7-day holter monitoring was obtained 3, 6, and 12 months after ablation. After a 12-month follow-up time, 83.8% of patients without LVAs (<10%) were free of atrial fibrillation, while 50.0% of patients with 10% to 30% LVAs and 9.1% of patients with LVAs more than 30% had stable sinus rhythm. The degree of atrial fibrosis correlated with the risk of AF recurrence.

CONCLUSION

In patients with persistent AF undergoing CB PVI, the extent of left atrial LVAs predicts an AF-free survival. CB PVI seems to be a highly effective treatment for patients with persistent AF without atrial fibrosis.

Patient characteristics as predictors of recurrence of atrial fibrillation following cryoballoon ablation

BACKGROUND

While several studies have evaluated predictors for atrial fibrillation (AF) recurrence following catheter ablation, there are limited data specific to cryoballoon ablation (CBA).

METHODS

We analyzed a prospective registry of patients at a single institution who underwent CBA. Recurrence of AF (RAF) was defined as recurrence of AF by 12-month follow-up, excluding the 3-month blanking period. Univariate analysis was performed to evaluate predictors of RAF. Receiver operating characteristic analysis was used to compare and evaluate the performance of various risk scores for discriminating risk of RAF.

RESULTS

There were 542 patients included in the analysis with mean age 61.3 ± 10.6 years, 67.9% male, and 51.6% paroxysmal AF (PAF). Overall, only left atrial diameter (LAD) > 40 mm and ERAF (early recurrence of AF within 0-3 month blanking period) were significant predictors of RAF. In the PAF specific subgroup, LAD > 40 mm, AF duration > 12 months, prior stroke or transient ischemic attack, ERAF, and having previously failed an antiarrhythmic drug were significant predictors of RAF. In persistent AF (PeAF) subgroup, obstructive sleep apnea (OSA) and ERAF were significant predictors of RAF. Out of clinical risk scores tested, BASEAF2 had the highest performance with area under the curve of 0.646 (95% confidence interval [0.548, 0.708]; P < .01).

CONCLUSIONS

In this single-center retrospective study of CBA, we found only LAD > 40 mm and ERAF to be predictors of RAF. We identified OSA as a potential targetable risk factor in PeAF patients undergoing CBA. Out of risk scores tested for discriminating risk of RAF, BASEAF2 had the best performance.