Cryoballoon Versus High-Power, Short-Duration Radiofrequency Ablation for Pulmonary Vein Isolation in Patients With Paroxysmal Atrial Fibrillation: A Single-Center, Prospective, Randomized Study

Long-term Outcome of Cryoballoon Ablation in Korean Patients With Atrial Fibrillation: Real-World Experience From the Cryo Global Registry

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF), the most common atrial arrhythmia (AA), is an increasing healthcare burden in Korea. The objective of this sub-analysis of the Cryo Global Registry was to evaluate long-term efficacy, symptom burden, quality of life (QoL), and healthcare utilization outcomes and factors associated with AA recurrence in Korean patients treated with cryoballoon ablation (CBA).

METHODS

Patients were treated and followed up according to local standard-of-care in 3 Korean hospitals. Kaplan-Meier estimates were used in analyzing (1) efficacy defined as freedom from ≥30 second recurrence of AA at 24 months, (2) healthcare utilization, and (3) predictors of 24-month AA recurrence. Patient-reported QoL (using European Quality of Life-5 Dimensions-3 Levels) and predefined AF-related symptoms were assessed at baseline and 24-month follow-up.

RESULTS

Efficacy was 71.9% in paroxysmal AF (PAF) and 49.3% in persistent AF (PsAF) patients (p<0.01). A larger left atrial diameter (LAD), an increased time from AF diagnosis to CBA, and PsAF were independent predictors of AA recurrence. The percentage of patients with no AF symptoms significantly increased from baseline (24.5%) to 24-month (89.5%) follow-up (p<0.01). Improvement in QoL from baseline to 24 months was not statistically different between AF cohorts. PAF patients experienced greater freedom from repeat ablations (93.9% vs. 81.4%) and cardiovascular hospitalizations (91.3% vs. 72.5%, p<0.001 for both).

CONCLUSIONS

In alignment with global outcomes, CBA is an effective treatment for AF in the Korean population, with patients possessing a large LAD and not receiving ablation soon after diagnosis being the most at risk for AA recurrence.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02752737.

A meta-analysis and cost-minimization analysis of cryoballoon ablation versus radiofrequency ablation for paroxysmal atrial fibrillation

Background

Previous studies have shown inconsistent results in clinical effectiveness between cryoballoon ablation (CBA) and radiofrequency ablation (RFA), and cost assessment between the procedures is important. The aim of this study was to evaluate the clinical effectiveness and cost-effectiveness between the procedures in patients with paroxysmal atrial fibrillation (AF) refractory to antiarrhythmic drug therapy.

Methods

A systematic review and meta-analysis were performed. The primary outcome for the meta-analysis was long-term AF recurrence. Following the results of the meta-analysis, the cost-effectiveness of CBA versus RFA in Japan was assessed.

Results

The meta-analysis included 12 randomized controlled trials and six propensity-score matching cohort studies. AF recurrence was slightly lower in patients referred for CBA than for RFA, with an integrated risk ratio of 0.93 (95% confidence interval: 0.81-1.07) and an integrated hazard ratio of 0.96 (95% confidence interval: 0.77-1.19), but no significant difference was found. A cost-minimization analysis was conducted to compare the medical costs of CBA versus RFA because there was no significant difference in the risk of AF recurrence between the procedures. The estimated costs for CBA and RFA were JPY 4 858 544 (USD 32 390) and JPY 4 505 255 (USD 30 035), respectively, with cost savings for RFA of JPY 353 289 (USD 2355).

Conclusion

Our meta-analysis suggests that CBA provides comparable benefits with regard to AF recurrence compared with RFA, as shown in previous studies. Although the choice of treatment should be based on patient and treatment characteristics, RFA was shown that it might be cost saving as compared to CBA.

Using computed tomogram atrial myocardial thickness maps in high-power short-duration radiofrequency pulmonary vein isolation: UTMOST AF

Background

High-power short-duration (HPSD) ablation creates wide, shallow lesions using radiofrequency (RF) heating. It is uncertain if adjusting RF energy based on atrial wall thickness provides extra benefits. We studied the safety and effectiveness of tailored HPSD energy based on left atrial (LA) wall thickness (LAWT) for circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (PAF).

Methods

We enrolled 212 patients (68.4% male, mean age: 59.5 ± 11.0 years) and randomly assigned them to two groups: LAWT-guided CPVI (WT, n = 108) and conventional CPVI (control, n = 104). Both groups used an open irrigated-tip deflectable catheter to apply 50 W for 10 s to the posterior LA, while controls used 60 W for 15 s on other LA regions. RF delivery time in WT was titrated (15 s at LAWT > 2.1 mm, 13 s at 1.4-2.1 mm, and 11 s at <1.4 mm) according to the computed tomogram-myocardial thickness color map.

Results

After a mean follow-up of 13.4 ± 7.0 months, the WT and control groups showed no significant difference regarding clinical recurrence rate (13.9% vs. 5.8%, respectively; p = .061) and major complication rate (4.6% vs. 3.8%, respectively; p > .999). The total procedure time, cardioversion rate, and post-procedural AAD prescription rates did not significantly differ between the groups.

Conclusions

The LAWT-guided energy titration strategy did not result in improved procedural safety and efficacy compared to the conventional 50-60 W-HPSD CPVI in patients with PAF.

Cryoablation versus hybrid radiofrequency with high- and very-high-power short-duration catheter ablation for the treatment of paroxysmal atrial fibrillation

BACKGROUND

High-power short-duration (HPSD) and very-high-power short-duration (vHPSD-90 W/4 s) radiofrequency (RF) technology has reduced the procedure time of pulmonary vein isolation (PVI) using RF without compromising the efficacy of the technique. The current study compares the novel technology of HPSD/vHPSD with cryoablation (CRYO) in terms of efficacy, safety, and procedure time in a cohort of symptomatic patients with paroxysmal atrial fibrillation (pAF).

METHODS

This is a prospective, non-randomized trial. Patients with pAF received either CRYO or HPSD/vHPSD RF PVI. The primary endpoint of the study was arrhythmia recurrence in a 12 month follow-up period. Secondary endpoints included procedure time, fluoroscopy time, and safety.

RESULTS

104 patients were included (45 in HPSD/vHPSD and 59 in CRYO), with comparable characteristics between groups. The follow-up was 12.4 ± 0.5 months. There was no significant difference regarding arrhythmia recurrences during the early post-procedural period of the first 3 months (8.9% recurrences in HPSD/vHPSD versus 5.1% in CRYO-p 0.463) and in the mid-term follow-up of 12 months (17.8% recurrences in HPSD/vHPSD versus 10.2% in CRYO-p 0.385). Safety was excellent for both procedures. CRYO was a procedure of significantly shorter duration (64.64 ± 8.94 min versus 75.29 ± 18.30 min, p = 0.0001) at the expense of longer fluoroscopy time (HPSD/vHPSD 5.34 ± 1.83 versus 7.89 ± 3.70 min CRYO, p 0.001).

CONCLUSIONS

HPSD/vHPSD and CRYO in pAF were comparable regarding the arrhythmia recurrence rates in a 12-month follow-up with excellent safety. The hybrid approach of HPSD/vHPSD has accelerated RF-PVI compared to conventional RF, but CRYO remains a procedure of significantly shorter duration at the expense of longer fluoroscopy time.

Anti- and pro-fibrillatory effects of pulmonary vein isolation gaps in human atrial fibrillation digital twins

Although pulmonary vein isolation (PVI) gaps and extrapulmonary vein triggers contribute to recurrence after atrial fibrillation (AF) ablation, their precise mechanisms remain unproven. Our study assessed the impact of PVI gaps on rhythm outcomes using a human AF digital twin. We included 50 patients (76.0% with persistent AF) who underwent catheter ablation with a realistic AF digital twin by integrating computed tomography and electroanatomical mapping. We evaluated the final rhythm status, including AF and atrial tachycardia (AT), across 600 AF episodes, considering factors including PVI level, PVI gap number, and pacing locations. Our findings revealed that antral PVI had a significantly lower ratio of AF at the final rhythm (28% vs. 56%, p = 0.002) than ostial PVI. Increasing PVI gap numbers correlated with an increased ratio of AF at the final rhythm (p < 0.001). Extra-PV induction yielded a higher ratio of AF at the final rhythm than internal PV induction (77.5% vs. 59.0%, p < 0.001). In conclusion, our human AF digital twin model helped assess AF maintenance mechanisms. Clinical trial registration: https://www.clinicaltrials.gov ; Unique identifier: NCT02138695.

Comparison of pulmonary vein isolation using cryoballoon, high-power short-duration, and conventional radiofrequency ablation for atrial fibrillation: a propensity score-weighted study

Background

The comparative efficacy, saftey, and heart rate variability (HRV) parameters after pulmonary vein isolation using cryoballoon (Cryo-PVI), high-power short-duration (HPSD-PVI), and conventional radiofrequency ablation (conventional-PVI) for atrial fibrillation (AF) is unclear.

Materials and methods

In this propensity score-weighted, retrospective analysis of a single-center cohort, we analyzed 3,395 patients (26.2% female, 74.5% paroxysmal AF) who underwent AF catheter ablation without an empirical left atrial ablation. Procedural factors, recurrence rates, complication rates, and the post-procedural HRV parameters were compared across the Cryo-PVI (n = 625), HPSD-PVI (n = 748), and conventional-PVI (n = 2,022) groups.

Results

Despite the shortest procedural time in the Cryo-PVI group (74 min for Cryo-PVI vs. 104 min for HPSD-PVI vs. 153 min for conventional-PVI, p < 0.001), the major complication (p = 0.906) and clinical recurrence rates were similar across the three ablation groups (weighted log-rank, p = 0.824). However, the Cryo-PVI group was associated with a significantly lower risk of recurrent AF in patients with paroxysmal AF [weighted hazard ratio (WHR) 0.57, 95% confidence interval (CI) 0.37-0.86], whereas it was associated with a higher risk of recurrent AF in patients with persistent AF (WHR 1.41, 95% CI 1.06-1.89, p for interaction of <0.001) compared with the conventional-PVI group. In the subgroup analysis for the HRV, the Cryo-PVI group had the highest low-frequency-to-high-frequency ratio at 1-year post-procedure, whereas the HPSD-PVI group had the lowest low-frequency-to-high-frequency ratio at 1-year post-procedure (p < 0.001).

Conclusions

The Cryo-PVI group had better rhythm outcomes in patients with paroxysmal AF but worse rhythm outcomes in patients with persistent AF and a higher long-term post-procedural sympathetic nervous activity and sympatho-vagal balance compared with the conventional-PVI group.

Comparison of efficacy of pulmonary vein isolation between cryoballoon ablation and high-power short-duration ablation

BACKGROUND

High-power short-duration (HPSD) and cryoballoon ablation (CBA) has been used for pulmonary vein isolation (PVI).

OBJECTIVE

We aimed to compare the efficacy of PVI between CBA and HPSD ablation in patients with paroxysmal atrial fibrillation (PAF).

METHODS

We retrospectively analyzed 251 consecutive PAF patients from January 2018 to July 2020. Of them, 124 patients (mean age 57.2 ± 10.1 year) received HPSD and 127 patients (mean age 59.6 ± 9.4 year) received CBA. In HPSD group, the radiofrequency energy was set as 50 W/10 s at anterior wall and 40 W/10 s at posterior wall. In CBA group, 28 mm s generation cryoballoon was used for PVI according the guidelines.

RESULTS

There was no significant difference in baseline characteristics between these 2 groups. The time to achieve PVI was significantly shorter in cryoballoon ablation group than in HPSD group (20.6 ± 1.7 min vs 51.8 ± 36.3, P = 0.001). The 6-month overall recurrence for atrial tachyarrhythmias was not significantly different between the two groups (HPSD:14.50% vs CBA:11.0%, P = 0.40). There were different types of recurrent atrial tachyarrhythmia between these 2 groups. Recurrence as atrial flutter was significantly more common in CBA group compared to HPSD group (57.1% vs 12.5%, P = 0.04).

CONCLUSION

In PAF patients, CBA and HPSD had a favourable and comparable outcome. The recurrence pattern was different between CBA and HPSD groups.

How the new technologies and tools will change the electrophysiology of the future

Novel technologies and therapies are evolving rapidly in the field of electrophysiology and cardiac ablation, particularly with the aim of improving the management of atrial fibrillation (AF) where pharmacologic treatment fails. High-power short-duration radiofrequency (RF) ablation, in association with the optimized cooling process of the electrode-tissue interface, is one of the most promising approaches for treating durable lesions and pulmonary vein isolation (PVI). Cryo energy, laser, and RF current are examples of novel tools used by competitive balloon catheter platforms and these tools are specifically created to properly promote an effective PVI. Specific mention deserves to be made on the linear array ablation with ultra-low temperature cryoablation that appears promising for durable lesions. It is needless to remind here about the novel evolving energy source in the form of pulsed electrical field (PFA), which results in an irreversible electroporation of myocardial tissue, sparing the surrounding tissue, and thus, apparently with a significant reduction of potential untoward effects. Furthermore, intensive research is in place to specifically investigate the activation pattern of AF so as to devise a patient-('tailored') target ablation, although with inhomogeneous results. Overall, it seems that technologies and therapies are evolving so rapidly than ever with the hope of achieving better long-term clinical results and an improved quality of life for our patients.

Left atrial appendage occlusion combined with cryoballoon or radiofrequency ablation: One-year follow-up comparison

Background

A one-stop procedure involving catheter ablation and left atrial appendage occlusion (LAAO) is an option for high-risk atrial fibrillation patients. Few studies have reported the efficacy and safety of cryoballoon ablation (CBA) combined with LAAO, and no studies have compared the combination of LAAO with CBA or radiofrequency ablation (RFA).

Methods

A total of 112 patients were enrolled in the present study; 45 patients received CBA combined with LAAO (group 1), and 67 patients received RFA combined with LAAO (group 2). Patient follow-up was performed for 1 year to detect peri-device leaks (PDLs) and safety outcomes (defined as a composite of peri-procedural and follow-up adverse events).

Results

The number of PDLs at the median 59 days follow-up was comparable between the two groups (33.3% in group 1 vs. 37.3% in group 2, p = 0.693). Safety outcomes were also comparable between the two groups (6.7% in group 1 vs. 7.5% in group 2, p = 1.000). Multivariable regression showed that PDLs risk and safety outcomes were all similar between the two groups. Subgroup analysis of PDLs indicated no significant differences. Follow-up safety outcomes were related to anticoagulant medication, and patients without PDLs were more likely to discontinue antithrombotic therapy. The total procedure and ablation times were all significantly shorter for group 1.

Conclusion

When compared with left atrial appendage occlusion combined with radiofrequency, left atrial appendage occlusion combined with cryoballoon ablation has the same risk of peri-device leaks and safety outcomes, but the procedure time was significantly reduced.

Pulmonary vein isolation for atrial fibrillation using true high-power short-duration vs. cryoballoon ablation

AIMS

Pulmonary vein isolation (PVI) is achievable and effective using radiofrequency (RF) catheter (CA) or cryoballoon (CB) ablation. The newly introduced high RF-power short-duration ablation (HPSD) technique has shown promising results. Data comparing HPSD- to CB-PVI is sparse. We sought to investigate success rates and procedural differences of HPSD-PVI vs. CB-PVI in patients undergoing ablation for PAF and persAF.

METHODS

Consecutive patients undergoing de novo PVI (HPSD or CB) were included. A power setting of 70W/7 s (70W/5 s at posterior wall) using a flexible tip catheter with enhanced irrigation was considered as true HPSD. Follow-up consisted of out-clinic pts visits, tele-consultation, 48-h Holter ECG, app-based telemonitoring and cardiac implanted electronic devices (CIED) interrogation.

RESULTS

721 patients (46 HPSD, 675 CB) were analyzed. In all HPSD (27 persAF [59%]) and CB patients (423 persAF [63%]), PVI was successfully achieved. Procedure duration was significantly longer for HPSD (91 ± 19 min vs. 72 ± 18 min, p < 0.01). Ablation time was similar in both groups (HPSD: 44 ± 19 min vs. CB: 40 ± 17 min; p = 0.347). No major complications occurred in HPSD. For CB-PVI, in 25 (3.7%; p = 0.296) patients, complications occurred. At a follow-up of 290 ± 135 days, arrhythmia-free survival using HPSD was non-inferior to CB-PVI in the Kaplan-Meier survival analysis (p = 0.096).

CONCLUSION

PVI using HPSD is equally effective and safe to CB-PVI. This analysis revealed a similar arrhythmia-free survival after HPSD and CB with low complication rates. Procedure duration for CB was significantly shorter while LA dwell time excluding mapping was equal. Currently, a prospective trial is conducted to corroborate these findings.

Ablation therapies for paroxysmal atrial fibrillation: A systematic review and patient-level network meta-analysis

Introduction: Despite promising trials, catheter ablation is still regarded as an adjunct to antiarrhythmic drugs (AADs) in the treatment of paroxysmal atrial fibrillation (PAF). This study aimed to compare the effectiveness of various ablation therapies and AAD. Method: Randomised controlled trials or propensity score-matched studies comparing atrial tachyarrhythmia recurrence among any combination of ablation modalities or AAD were retrieved. Kaplan-Meier curves and risk tables for this outcome were graphically reconstructed to extract patient-level data. Frequentist network meta-analysis (NMA) using derived hazard ratios (HRs), as well as 2 restricted mean survival time (RMST) NMAs, were conducted. Treatment strategies were ranked using P-scores. Results: Across 24 studies comparing 6 ablation therapies (5,132 patients), Frequentist NMA-derived HRs of atrial fibrillation recurrence compared to AAD were 0.35 (95% confidence interval [CI]=0.25–0.48) for cryoballoon ablation (CBA), 0.34 (95% CI=0.25–0.47) for radiofrequency ablation (RFA), 0.14 (95% CI=0.07–0.30) for combined CBA and RFA, 0.20 (95% CI=0.10–0.41) for hot-balloon ablation, 0.43 (95% CI=0.15–1.26) for laser-balloon ablation (LBA), and 0.33 (95% CI=0.18–0.62) for pulmonary vein ablation catheter. RMST-based NMAs similarly showed significant benefit of all ablation therapies over AAD. The combination of CBA + RFA showed promising long-term superiority over CBA and RFA, while LBA showed favourable short-term efficacy. Conclusion: The advantage of ablation therapies over AAD in preventing atrial tachyarrhythmia recurrence suggests that ablation should be considered as the first-line treatment for PAF in patients fit for the procedure. The promising nature of several specific therapies warrants further trials to elicit their long-term efficacy and perform a cost-benefit analysis. Keywords: Atrial fibrillation, catheter ablation, network meta-analysis

Percutaneous Treatment Approaches in Atrial Fibrillation: Current Landscape and Future Perspectives

Atrial fibrillation (AF), the most common sustained arrhythmia in clinical practice, represents a major cause of morbidity and mortality, with an increasing prevalence. Pharmacologic treatment remains the cornerstone of its management through rhythm and rate control, as well as the prevention of thromboembolism with the use of oral anticoagulants. Recent progress in percutaneous interventional approaches have provided additional options in the therapeutic arsenal, however. The use of the different catheter ablation techniques can now lead to long arrhythmia-free intervals and significantly lower AF burden, thus reducing the rate of its complications. Particularly encouraging evidence is now available for patients with persistent AF or concomitant heart failure, situations in which catheter ablation could even be a first-line option. In the field of stroke prevention, targeting the left atrial appendage with percutaneous device implantation may reduce the risk of thromboembolism to lower rates than that predicted with conventional ischemic risk scores. Left atrial appendage occlusion through the approved Watchman or Amplatzer devices is a well-established, efficacious, and safe method, especially in high-ischemic and bleeding risk patients with contraindications for oral anticoagulation.

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 Usefulness of Virtual Ablation Guided Catheter Ablation of Atrial Fibrillation Targeting Restitution Parameter-Guided Catheter Ablation: CUVIA-REGAB Prospective Randomized Study

BACKGROUND AND OBJECTIVES

We investigated whether extra-pulmonary vein (PV) ablation targeting a high maximal slope of the action potential duration restitution curve (Smax) improves the rhythm outcome of persistent atrial fibrillation (PeAF) ablation.

METHODS

In this open-label, multi-center, randomized, and controlled trial, 178 PeAF patients were randomized with 1:1 ratio to computational modeling-guided virtual Smax ablation (V-Smax) or empirical ablation (E-ABL) groups. Smax maps were generated by computational modeling based on atrial substrate maps acquired during clinical procedures in sinus rhythm. Smax maps were generated during the clinical PV isolation (PVI). The V-Smax group underwent an additional extra-PV ablation after PVI targeting the virtual high Smax sites.

RESULTS

After a mean follow-up period of 12.3±5.2 months, the clinical recurrence rates (25.6% vs. 23.9% in the V-Smax and the E-ABL group, p=0.880) or recurrence appearing as atrial tachycardia (11.1% vs. 5.7%, p=0.169) did not differ between the 2 groups. The post-ablation cardioversion rate was higher in the V-Smax group than E-ABL group (14.4% vs. 5.7%, p=0.027). Among antiarrhythmic drug-free patients (n=129), the AF freedom rate was 78.7% in the V-Smax group and 80.9% in the E-ABL group (p=0.776). The total procedure time was longer in the V-Smax group (p=0.008), but no significant difference was found in the major complication rates (p=0.497) between the groups.

CONCLUSIONS

Unlike a dominant frequency ablation, the computational modeling-guided V-Smax ablation did not improve the rhythm outcome of the PeAF ablation and had a longer procedure time.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02558699.

New energy sources and technologies for atrial fibrillation catheter ablation

Ablation has become a cornerstone for the management of symptomatic atrial fibrillation (AF) in patients where anti-arrhythmic drugs fail. Electrical isolation of the pulmonary veins (PVs) is the basic step for every procedure but is still hampered by tools and energy sources that do not lead to durability of isolation. Novel therapies include high power short duration radiofrequency ablation in combination with optimal cooling of the electrode-tissue interface by irrigation or new electrode material to allow for optimal safe energy transfer. Novel tools include competitive balloon catheters using cryoenergy, laser, or radiofrequency current, or linear array ablation with ultralow temperature cryoablation to enhance durability of lesions. A novel energy source is rapidly evolving in the form of pulsed electrical field ablation resulting in irreversible electroporation of cardiac tissue, potentially without collateral side effects. Beyond PV isolation, ablation targets are still under study as standardized addition of lesion lines shows limited benefits. Mapping of the activation pattern during AF to guide patient-specific target ablation has been developing over the last decade, with mixed results by different platforms. The field of ablation for AF is evolving more rapidly than ever which will hopeful result in better long-term outcomes.

Association of ZFHX3 Genetic Polymorphisms and Extra-Pulmonary Vein Triggers in Patients With Atrial Fibrillation Who Underwent Catheter Ablation

Background: The ZFHX3 gene (16q22) is the second most highly associated gene with atrial fibrillation (AF) and is related to inflammation and fibrosis. We hypothesized that ZFHX3 is associated with extra-pulmonary vein (PV) triggers, left atrial (LA) structural remodeling, and poor rhythm outcomes of AF catheter ablation (AFCA). Methods: We included 1,782 patients who underwent a de novo AFCA (73.5% male, 59.4 ± 10.8 years old, 65.9% paroxysmal AF) and genome-wide association study and divided them into discovery (n = 891) and replication cohorts (n = 891). All included patients underwent isoproterenol provocation tests and LA voltage mapping. We analyzed the ZFHX3, extra-PV trigger-related factors, and rhythm outcomes. Result: Among 14 single-nucleotide polymorphisms (SNPs) of ZFHX3, rs13336412, rs61208973, rs2106259, rs12927436, and rs1858801 were associated with extra-PV triggers. In the overall patient group, extra-PV triggers were independently associated with the ZFHX3 polygenic risk score (PRS) (OR 1.65 [1.22-2.22], p = 0.001, model 1) and a low LA voltage (OR 0.74 [0.56-0.97], p = 0.029, model 2). During 49.9 ± 40.3 months of follow-up, clinical recurrence of AF was significantly higher in patients with extra-PV triggers (Log-rank p < 0.001, HR 1.89 [1.49-2.39], p < 0.001, model 1), large LA dimensions (Log-rank p < 0.001, HR 1.03 [1.01-1.05], p = 0.002, model 2), and low LA voltages (Log-rank p < 0.001, HR 0.73 [0.61-0.86], p < 0.001, model 2) but not the ZFHX3 PRS (Log-rank p = 0.819). Conclusion: The extra-PV triggers had significant associations with both ZFHX3 genetic polymorphisms and acquired LA remodeling. Although extra-PV triggers were an independent predictor of AF recurrence after AFCA, the studied AF risk SNPs intronic in ZFHX3 were not associated with AF recurrence.

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 Catheter Ablation in Korean Patients With Paroxysmal and Persistent Atrial Fibrillation: One Year Outcome From the Cryo Global Registry

Catheter ablation using the cryoballoon is a well-established treatment strategy for patients with atrial fibrillation (AF). To our knowledge, the current sub-analysis of the Cryo Global Registry is the first multicenter study describing the outcomes of cryoballoon ablation (CBA) in real-world Korea clinical practice. Overall, 299 patients were enrolled in 3 Korean centers. Safety, efficacy, healthcare utilization, and arrhythmia disease burden outcomes were assessed. This study demonstrated that CBA according to standard-of-care usage in Korea is safe and effective in preventing AF recurrence, repeat ablation, cardiovascular-related hospitalization, and AF-related symptoms at 12 months after the index ablation.

Background and Objectives

Cryoballoon catheter ablation for the treatment of patients with symptomatic atrial fibrillation (AF) has been adopted globally, but there are limited multicenter reports of 12-month outcomes in the Korean patient population. This analysis evaluated the clinical performance and safety of cryoballoon ablation (CBA) according to standard-of-care practices in Korea.

Methods

This evaluation of Korean patients with AF was conducted within the larger Cryo Global Registry, which is a prospective, multicenter, post-market registry. Freedom from a ≥30-second recurrence of atrial arrhythmias (after a 90-day blanking period until 12 months) and procedural safety were examined in subjects treated with CBA at 3 Korean centers.

Results

Overall, 299 patients with AF (60±11 years old, 24.7% female, 50.5% paroxysmal AF) underwent CBA using the Arctic Front Advance cryoballoon. Of those, 298 were followed-up for at least 12 months. Mean procedure-, left atrial dwell- and fluoroscopy time was 76±21 minutes, 56±23 minutes, and 27±23 minutes, respectively. Freedom from AF recurrence at 12 months was 83.9% (95% confidence interval [CI], 76.9–88.9%) in the paroxysmal and 61.6% (95% CI, 53.1–69.0%) in the persistent AF cohort. Rhythm monitoring was performed on average 4.7±1.4 times during the follow-up period. Serious device- or procedure-related adverse events occurred in 2 patients (0.7%). The 12-month Kaplan-Meier estimate of freedom from repeat ablation and cardiovascular-related hospitalization was 93.8% (95% CI, 90.4–96.1%) and 89.7% (95% CI, 85.6–92.7%), respectively.

Conclusions

CBA is an efficient, effective, and safe procedure for the treatment of AF patients when used according to real-world practices in Korea.

Trial Registration

ClinicalTrials.gov Identifier: NCT02752737

Radiofrequency vs. Cryoballoon vs. Thoracoscopic Surgical Ablation for Atrial Fibrillation: A Single-Center Experience

Background and Objectives: Cryoballoon ablation (CBA) and totally thoracoscopic surgical ablation (TTA) have emerged as alternatives to radiofrequency catheter ablation (RFCA) for atrial fibrillation. In this study, we describe our experience comparing patient characteristics and outcomes of RFCA, CBA, and TTA. Materials and Methods: We retrospectively analyzed data from patients who underwent RFCA, CBA, or TTA. Both atrial fibrillation (AF)- and atrial tachyarrhythmia (ATa)-free survival rates were compared using time to recurrence after a 3-month blanking period (defined by a duration of more than 30 s). All patients were regularly followed using 12-lead ECGs or Holter ECG monitoring. Results: Of 354 patients in this study, 125 underwent RFCA, 97 underwent CBA and 131 underwent TTA. The TTA group had more patients with persistent AF, a larger LA diameter, and a history of stroke. The CBA group showed the shortest procedure time (p < 0.001). The CBA group showed significantly lower AF-free survival at 12 months than the RFCA and TTA groups (RFCA 84%, CBA 74% and TTA 85%, p = 0.071; p = 0.859 for TTA vs. RFCA, p = 0.038 for RFCA vs. CBA and p = 0.046 for TTA vs. CBA). There were no significant differences in ATa-free survival among the three groups (p = 0.270). There were no procedure-related adverse events in the RFCA group, but some complications occurred in the CBA group and the TTA group (6% and 5%, respectively). Conclusions: RFCA and CBA are effective and safe as first-line treatments for paroxysmal and persistent AF. In some high-risk stroke patients, TTA may be a viable option. It is important to consider patient characteristics when selecting an ablation method for AF.