Early Recurrence After Pulmonary Vein Isolation of Paroxysmal Atrial Fibrillation With Different Ablation Technologies - Prospective Comparison of Radiofrequency vs. Second-Generation Cryoballoon Ablation

Predictors of late recurrence after second catheter ablation for persistent atrial fibrillation

BACKGROUND

Little has been reported on the predictors of late recurrence (LR) after second radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (AF).

OBJECTIVE

This study aimed to identify the predictors of LR after second RFCA in patients with persistent AF.

METHODS

We retrospectively analyzed 123 patients who underwent a second RFCA because of LR after the initial RFCA for persistent AF. LR was defined as a recurrence of atrial tachyarrhythmia >3 months after the ablation procedure. The initial RFCA included pulmonary vein isolation alone or pulmonary vein isolation plus cavotricuspid isthmus block. The predictors of LR were evaluated by the Cox proportional hazards model.

RESULTS

In the univariate analysis, elevated brain natriuretic peptide levels, absence of pulmonary vein reconnections at the beginning of the second RFCA, and presence of early recurrence (ER, defined as a recurrence of atrial tachyarrhythmia within 3 months) after the second RFCA were associated with LR (P = .025, P = .018, and P < .001, respectively). The multivariate analysis revealed that absence of pulmonary vein reconnections and presence of ER were independent predictors of LR after the second RFCA (P = .004 and P < .001, respectively).

CONCLUSION

Absence of pulmonary vein reconnections and presence of ER were strongly associated with LR after the second RFCA in patients with persistent AF.

Impact of different energy sources on coagulation biomarkers and silent cerebral events in balloon-based ablation for atrial fibrillation

Background

Different energy sources of balloon-based ablation for pulmonary vein isolation cause different kinds of endothelial damage and coagulation responses associated with thromboembolic risk.

Objectives

The study sought to compare the impact of different balloon-based ablation, cryoballoon ablation (CBA) and laser balloon ablation (LBA), on coagulation/fibrinolysis biomarkers and silent cerebral events (SCEs) in paroxysmal atrial fibrillation.

Methods

Paroxysmal atrial fibrillation patients who underwent pulmonary vein isolation using either CBA (n = 52) or LBA (n = 53) without radiofrequency touch-up ablation were eligible. Time course (day 0 [before ablation], day 1, day 2, and day 28) of myocardial enzymes and inflammatory and coagulation/fibrinolysis biomarkers was evaluated during the perioperative period. Brain magnetic resonance imaging was performed within 2 days after the procedure to evaluate SCEs.

Results

There was no difference in patient characteristics between CBA and LBA.CBA had greater myocardial injury (troponin I and creatine kinase-MB) and lower inflammatory reaction (white blood cell count and neutrophil/lymphocyte ratio) than LBA. The coagulation biomarkers maximally increased by day 2 and then decreased in both groups. In day 28, the serum prothrombin fragment 1+2 and D-dimer levels in LBA were significantly higher than the values in CBA. The fibrinolysis biomarker (plasmin-α2 plasmin inhibitor complex) did not increase after the procedure in either group. The incidence of SCEs was comparable between CBA and LBA (11% vs 15%; P = .591). No thromboembolic event was observed.

Conclusion

CBA and LBA had different effects on myocardial injury, inflammatory reaction, and coagulation activity but did not affect the incidence of thromboembolic events. LBA had significantly higher coagulation activity in day 28 and may require more careful postprocedural anticoagulation than CBA.

Myocardial injury and inflammation following pulsed-field ablation and very high-power short-duration ablation for atrial fibrillation

INTRODUCTION

Pulmonary vein isolation (PVI) using radiofrequency ablation (RFA) is an established treatment strategy for atrial fibrillation (AF). To improve PVI efficacy and safety, high-power short-duration (HPSD) ablation and pulsed-field ablation (PFA) were recently introduced into clinical practice. This study aimed to determine the extent of myocardial injury and systemic inflammation following PFA, HPSD, and standard RFA using established biomarkers.

METHODS

We included 179 patients with paroxysmal AF receiving first-time PVI with different ablation technologies: standard RFA (30-40 W/20-30 s, n = 52), power-controlled HPSD (70 W/5-7 s, n = 60), temperature-controlled HPSD (90 W/4 s, n = 32), and PFA (biphasic, bipolar waveform, n = 35). High-sensitivity cardiac troponin T (hs-cTnT), creatine kinase (CK), CK MB isoform (CK-MB), and white blood cell (WBC) count were determined before and after ablation.

RESULTS

Baseline characteristics were well-balanced between groups (age 63.1 ± 10.3 years, 61.5% male). Postablation hs-cTnT release was significantly higher with PFA (1469.3 ± 495.0 ng/L), HPSD-70W (1322.3 ± 510.6 ng/L), and HPSD-90W (1441.2 ± 409.9 ng/L) than with standard RFA (1045.9 ± 369.7 ng/L; p < .001). CK and CK-MB release was increased with PFA by 3.4-fold and 5.8-fold, respectively, as compared to standard RFA (p < .001). PFA was associated with the lowest elevation in WBC (Δ1.5 ± 1.5 × 109 /L), as compared to standard RFA (Δ3.8 ± 2.5 × 109 /L, p < .001), HPSD-70W (Δ2.7 ± 1.7 × 109 /L, p = .037), and HPSD-90W (Δ3.6 ± 2.5 × 109 /L, p < .001).

CONCLUSION

Among the four investigated ablation technologies, PFA was associated with the highest myocardial injury and the lowest inflammatory reaction.

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.

Impact of very early recurrence of atrial fibrillation after cryoballoon ablation

BACKGROUND

Although much has been discussed about the early recurrence of atrial fibrillation (ERAF) after cryoballoon ablation (CBA), the clinical impact of very early recurrence of atrial fibrillation (VERAF) after CBA remains unclear. This study aimed to investigate the impact of VERAF after CBA.

METHODS

We enrolled 236 consecutive patients who underwent an initial CBA for paroxysmal atrial fibrillation between February 2017 and December 2020 in our hospital. These patients were categorized into three groups: VERAF group who experienced an initial recurrence of atrial tachyarrhythmia within 48 hours after CBA, late-ERAF (LERAF) group who experienced an initial recurrence of atrial tachyarrhythmia between 48 hours and 3 months after CBA, and non-ERAF (NERAF) group who did not experience a recurrence of atrial tachyarrhythmia within 3 months after CBA. We investigated the late recurrence of AF (LRAF, defined as recurrence of atrial tachyarrhythmia more than 3 months after CBA), and the incidence of non-pulmonary vein (PV) triggers in the patients who experienced a repeat ablation procedure due to LRAF.

RESULTS

VERAF group had a higher incidence of freedom from LRAF than LERAF group (P = 0.032) and a lower incidence of freedom from LRAF than NERAF group (P = 0.002). Moreover, VERAF group had the highest incidence of non-PV triggers at repeat ablation procedure among the three groups (P = 0.003).

CONCLUSIONS

While ERAF was a predictor of LRAF, VERAF was less related to LRAF among the patients with ERAF after CBA. Furthermore, VERAF might be associated with non-PV triggers. This article is protected by copyright. All rights reserved.

Early arrhythmia recurrence after cryoballoon ablation in atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Early arrhythmia recurrence within the three-month blanking period is a common event that historically has been attributed to reversible phenomena. While its' mechanistic links remain obscure, accumulating evidence support the argument of shortening the blanking period. We aimed to elucidate the association between early and late arrhythmia recurrence after atrial fibrillation cryoablation.

METHODS

The MEDLINE database, ClinicalTrials.gov, medRxiv and Cochrane Library were searched for studies evaluating early and late arrhythmia recurrence rates in patients undergoing cryoablation for AF. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was late arrhythmia recurrence.

RESULTS

Early arrhythmia recurrence was found predictive of decreased arrhythmia-free survival after evaluating 3975 patients with paroxysmal or persistent atrial fibrillation who underwent cryoablation (OR: 5.31; 95% CI: 3.75-7.51). This pattern remained unchanged after sub-analyzing atrial fibrillation type (paroxysmal; OR: 7.16; 95% CI: 4.40-11.65 and persistent; OR: 7.63; 95% CI: 3.62-16.07) as well as cryoablation catheter generation (first generation; OR: 5.15, 95% CI: 2.39-11.11 and advanced generation; OR: 5.83, 95% CI: 3.68-9.23). Studies permitting anti-arrhythmic drug utilization during blanking period or examining early recurrence as a secondary outcome were found to be a significant source of statistical heterogeneity.

CONCLUSION

Our findings suggest that early arrhythmia recurrence is predictive of late outcomes after cryoablation for atrial fibrillation. Identifying which patients deserve earlier re-intervention is an open research avenue. This article is protected by copyright. All rights reserved.

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.

The association between late-phase early recurrence within the blanking period after atrial fibrillation catheter ablation and long-term recurrence: Insights from a large-scale multicenter study

BACKGROUND

The relationship between the timing of the first early recurrence and late recurrence after a single catheter ablation procedure for atrial fibrillation is controversial.

METHODS

The Efficacy of Short-Term Use of Antiarrhythmic Drugs After Catheter Ablation for Atrial Fibrillation trial followed 2038 patients who underwent radiofrequency catheter ablation for atrial fibrillation.

RESULTS

Of the patients, 907 (45%) had early recurrences within 90 days after the initial ablation. We divided these patients into two groups according to the timing of the first early recurrence episode, namely the ER₁ group (early recurrence during the early phase; 0-30 days, n = 814) and ER₂ group (early recurrence during the late phase; 31-90 days, n = 93). Three years after ablation, patients with early recurrences had a significantly lower event-free rate from late recurrences after a 90-day blanking period than patients without early recurrences (36.2% and 74.2%, respectively; log-rank, P < 0.0001). Three years after ablation, the event-free rate was significantly higher in the ER₁ than the ER₂ group (38.3% and 17.1%, respectively; log-rank, P < 0.0001). Moreover, the event-free rate at 3 years in the ER₂ group was extremely low (5.6%) in patient with non-paroxysmal atrial fibrillation.

CONCLUSION

Early recurrences were strongly associated with late recurrences, especially in patients with the first recurrence episode at >1 month within the blanking period after a single ablation procedure. Therefore, these patients should undergo close observation during follow-up, when they had especially with non-paroxysmal atrial fibrillation.

Prevalence and outcome of early recurrence of atrial tachyarrhythmias in the Cryoballoon vs Irrigated Radiofrequency Catheter Ablation (CIRCA-DOSE) study

BACKGROUND

Early recurrence of atrial tachyarrhythmia (ERAT) is common after pulmonary vein isolation (PVI) and has been associated with an increased risk of late atrial fibrillation (AF) recurrence.

OBJECTIVE

The purpose of this study was to determine the incidence and outcomes of patients experiencing ERAT after PVI using advanced-generation ablation technologies.

METHODS

This is a prespecified substudy of the CIRCA-DOSE (Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double-Short vs Standard Exposure Duration) trial, a prospective, randomized, multicenter study comparing PVI with contact force-guided radiofrequency ablation to secondary-generation cryoballoon ablation for paroxysmal AF. All study patients received an implantable cardiac monitor to allow continuous rhythm monitoring. ERAT was defined as any recurrent atrial tachyarrhythmia within the first 90 days after AF ablation.

RESULTS

ERAT occurred in 61% of the 346 patients at a median of 12 days (range 1-90 days) after ablation. ERAF was a significant predictor of late recurrence (60.1% with ER vs 25.9% without ER; P <.001) and symptomatic atrial tachyarrhythmia (31.6% with ERAF vs 6.7% without ERAF; P <.001). Receiver operating curve analyses revealed a strong correlation between ERAT timing and burden and late recurrence. Multivariate analysis identified ER timing (hazard ratio [HR] 2.90; 95% confidence interval [CI] 1.41-5.95; P = .004) and burden (HR 1.05 per 1% ER burden; 95% CI 1.04-1.07; P <.001) as strong independent predictors of late recurrence. Incidence rate, timing, burden, and prognostic significance of ER did not differ between the study groups.

CONCLUSION

ERAT remains common after PVI despite use of advanced-generation ablation technologies. Early AF recurrence beyond 3 weeks after ablation is associated with increased risk of late recurrence.

Predictive role of early recurrence of atrial fibrillation after cryoballoon ablation

Aims

The aims of this study were to determine the rate and the predictors of early recurrences of atrial fibrillation (ERAF) after cryoballoon (CB) ablation and to evaluate whether ERAF correlate with the long-term outcome.

Methods and results

Three thousand, six hundred, and eighty-one consecutive patients (59.9 ± 10.5 years, female 26.5%, and 74.3% paroxysmal AF) were included in the analysis. Atrial fibrillation recurrence, lasting at least 30 s, was collected during and after the 3-month blanking period. Three-hundred and sixteen patients (8.6%) (Group A) had ERAF during the blanking period, and 3365 patients (Group B) had no ERAF. Persistent AF and number of tested anti-arrhythmic drugs ≥2 resulted as significant predictors of ERAF. After a mean follow-up of 16.8 ± 16.4 months, 923/3681 (25%) patients had at least one AF recurrence. The observed freedom from AF recurrence, at 24-month follow-up from procedure, was 25.7% and 64.8% in Groups A and B, respectively (P &lt; 0.001). ERAF, persistent AF, and number of tested anti-arrhythmic drugs ≥2 resulted as significant predictors of AF. In a propensity score matching, the logistic model showed that ERAF 1 month after ablation are the best predictor of long-term AF recurrence (P = 0.042).

Conclusion

In patients undergoing CB ablation for AF, ERAF are rare and are a strong predictor of AF recurrence in the follow-up, above all when occur &gt;30 days after the ablation.

Early recurrence during the blanking period and left atrial reverse remodeling after catheter ablation for non-paroxysmal atrial fibrillation

Background

Early recurrence of atrial tachyarrhythmia (ERAT) during a 90-day blanking period (BP) often occurs after atrial fibrillation (AF) ablation. Left atrial reverse remodeling (LARR), which is the reduction in LA volume (LAV), also occurs during the BP. Both ERAT and LARR are associated with late recurrence (LR, greater than 90 days after ablation). We investigated the association between ERAT and LARR following non-paroxysmal AF (NPAF) ablation.

Methods

We retrospectively reviewed 330 consecutive patients undergoing initial NPAF ablation (median follow-up: 4.0 years). Based on the timing of the final ERAT, we divided the patients into No-ERAT (N = 154, without ERAT), Early (N = 39, 0–7 days after ablation), Intermediate (N = 67, 8–30), and Late-ERAT (N = 70, 31–90) groups. We assessed the extent of LARR, defined as the percentage of decrease in LAV (%ΔLAV). The %ΔLAV cutoff value was determined by receiver operating characteristic analysis, and incorporated into a multivariate analysis to assess the association between ERAT and LARR.

Results

Late-ERAT was associated with LR (hazard ratio: 6.31, 95% confidence interval (CI): 4.21–9.47, p = 0.0001). The %ΔLAV in the Late-ERAT group was significantly smaller than the other groups (p < 0.0001). The predictive power of %ΔLAV for LR was slight (AUC, 0.604; best cutoff, 18.8% decrease; p = 0.0011). In the multivariate logistic regression analysis, Late-ERAT was associated with poor LARR (%ΔLAV < 18.8% decrease) (odds ratio, 0.13; 95%CI, 0.06–0.27; p < 0.001), whereas Early- and Intermediate-ERAT did not show any correlation.

Conclusions

Late-ERAT was strongly associated with poor LARR after NPAF ablation. Both Late-ERAT and poor LARR might reflect a residual arrhythmogenic substrate causing LR.

Re-definition of blanking period in radiofrequency catheter ablation of atrial fibrillation in the contact force era

INTRODUCTION

Early recurrence (ER) of atrial fibrillation (AF) is defined as the recurrence of atrial tachyarrhythmias within 3 months after AF ablation, however, this definition is based on data from the era of radiofrequency catheter ablation (RFCA), without contact force (CF) technology. We investigated the significance of ER as a risk factor for late recurrence (LR) in paroxysmal AF (PAF) patients treated with CF and non-CF-guided ablation.

METHODS AND RESULTS

We studied 395 patients with PAF who underwent RFCA. Of these, 97 patients underwent RFCA without-CF technology (non-CF group) and 298 underwent with CF technology (CF group). Over a 2-year postablation follow-up period, LR occurred in 54 (55.7%) patients in the non-CF group, and in 105 (35.2%) patients in the CF group. ER had a more significant relationship with LR in the CF group, and all patients in the CF group with ER in the third month developed LR.

CONCLUSION

PAF patients with ER who have undergone CF-guided ablation have a greater risk of LR than those who have undergone non-CF-guided ablation. ER in the third month after CF-guided ablation may indicate an absolute risk of LR. Blanking period could be defined as 2 months in the CF era.

Cryoballoon or radiofrequency ablation? Alternating technique for repeat procedures in patients with atrial fibrillation

BACKGROUND

Which technique is better for repeat ablation in patients with atrial fibrillation (AF) remains unclear. The aim of the study was to compare long-term efficacy of repeat ablation using the alternative technique for the first redo ablation procedure: (a) cryoballoon (CB) re-ablation after a failed index pulmonary vein isolation (PVI) with radiofrequency (RF) ablation, RF-then-CB group or (b) RF repeat ablation following a failed CB ablation, CB-then-RF group.

METHODS

Within the 1STOP Italian Project, consecutive patients undergoing repeat ablation with a different technique from the index procedure were included.

RESULTS

We studied 474 patients, 349 in RF-then-CB and 125 in CB-then-RF group. Less women (21% vs 30%; P = .041), more persistent AF (33% vs 22%; P = .015), longer duration of AF (60 vs 31 months; P < .001), and more hypertension (50% vs 36%; P = .007) were observed in the RF-then-CB cohort as compared with the CB-then-RF group. The number of reconnected PVs was 3.7 ± 0.7 and 1.4 + 1.3 in RF-then-CB and CB-then-RF group, respectively (P < .001). During the follow-up, significantly less AF recurrence occurred in the CB-then-RF group (22% vs 8%, HR = 0.46; 95% CI: 0.24-0.92; P = .025). Cohort designation was the only independent predictor of AF recurrence.

CONCLUSION

Alternation of energy source for repeat ablation was safe and effective, regardless the energy used first. However, patients initially treated with CB PVI undergoing repeat ablation with RF current had less AF recurrence at long-term follow-up as compared with those originally treated by RF ablation receiving a CB repeat ablation.

Cryoballoon pulmonary vein isolation-mediated rise of sinus rate in patients with paroxysmal atrial fibrillation

Background

Modulation of the cardiac autonomic nervous system by pulmonary vein isolation (PVI) influences the sinoatrial nodal rate. Little is known about the causes, maintenance and prognostic value of this phenomenon. We set out to explore the effects of cryoballoon PVI (cryo-PVI) on sinus rate and its significance for clinical outcome.

Methods and results

We evaluated 110 patients with paroxysmal atrial fibrillation (AF), who underwent PVI using a second-generation 28 mm cryoballoon by pre-, peri- and postprocedural heart rate acquisition and analysis of clinical outcome. Ninety-one patients could be included in postinterventional follow-up, indicating that cryo-PVI resulted in a significant rise of sinus rate by 16.5% (+ 9.8 ± 0.9 beats/min, p < 0.001) 1 day post procedure compared to preprocedural acquisition. This effect was more pronounced in patients with initial sinus bradycardia (< 60 beats/min.) compared to patients with faster heart rate. Increase of rate was primarily driven by ablation of the right superior pulmonary vein and for a subset of patients, in whom this could be assessed, persisted ≥ 1 year after the procedure. AF recurrence was neither predicted by the magnitude of the initial rate, nor by the extent of rate change, but postprocedural sinus bradycardia was associated with higher recurrence of AF in the year post PVI.

Conclusions

Cryo-PVI causes a significant rise of sinus rate that is more pronounced in subjects with previous sinus bradycardia. Patient follow-up indicates persistence of this effect and suggests an increased risk of AF recurrence in patients with postprocedural bradycardia.

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01659-0) contains supplementary material, which is available to authorized users.

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.

Cryothermal atrial linear ablation in patients with atrial fibrillation: An insight from the comparison with radiofrequency atrial linear ablation

BACKGROUND

Atrial linear lesions are generally created with radiofrequency energy. We sought to evaluate the feasibility of cryothermal atrial linear ablation.

METHODS AND RESULTS

Twenty-one atrial fibrillation (AF) patients underwent linear ablation on the left atrial (LA) roof, mitral isthmus (MI), and cavotricuspid isthmus (CTI) with 8-mm-tip cryocatheters following pulmonary vein isolation. The data were compared with those of 31 patients undergoing linear ablation with irrigated-tip radiofrequency catheters. Conduction block was successfully created in 18 of 20 (90%), 9 of 21 (43%), and 20 of 20 (100%) on the LA roof, MI, and CTI by endocardial cryoablation alone with 19.0 (12.0-24.0), 30.0 (23.0-34.0), and 14.0 (14.0-16.0) minute cryo applications, respectively. The presence of either an interposed circumflex artery or pouch at the MI was significantly associated with failed MI block (P = .04). Conduction block was created in 25 of 31 (83.9%), 27 of 31 (87.1%), and 30 of 31 (96.8%) on the roof, MI, and CTI, respectively, by radiofrequency ablation. During the 17.5 (13.0-31.7) months of follow-up, freedom from AF/atrial tachycardia (AT) was significantly higher in the cryo group (P = .05); especially, recurrent AT was more frequent in the RF group (8/31 vs 1/21; P = .03). Conduction block across the roof, MI, and CTI was durable in 6 of 12 (50.0%), 4 of 12 (33.3%), and 9 of 12 (75.0%) patients during second procedures. All nine patients (except one) with recurrent ATs had at least one roof or MI conduction resumption.

CONCLUSIONS

Cryoablation is effective for creating a roof and CTI linear block, however, creating MI block by endocardial ablation alone was often challenging. Conduction resumption of LA linear block is common and recurrent arrhythmias, especially iatrogenic ATs, are more frequently observed after radiofrequency linear ablation.

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.

Radiofrequency versus cryoballoon ablation for atrial fibrillation: an argument for a 'cryo-first' approach

PURPOSE OF REVIEW

Radiofrequency and cryoballoon ablation are the two most common modalities for catheter ablation of atrial fibrillation. Radiofrequency, being more prevalent and having existed for a longer period, is often utilized for patients' first ablations, despite the efficiency and efficacy of the cryoballoon tool. Here we examine the advantages of the cryoballoon for its use in first-time ablation of atrial fibrillation.

RECENT FINDINGS

The FIRE & ICE trial is established as conclusive evidence of the noninferiority of cryoballoon ablation to radiofrequency ablation in terms of efficacy. Since the study, cryoballoon has evolved in both form and technique, suggesting need for repeat consideration of the advantages of cryoablation over radiofrequency ablation. The second-generation cryoballoon has led to greater efficiency in achieving permanent pulmonary vein isolation, reducing complications, and reducing procedure times.

SUMMARY

There are advantages to the use of cryoballoon which could increase success of first-time ablations, delaying need for repeat procedure and lowering overall burden on patients and the healthcare system. Cryoballoon ablation should be considered for first-time ablation in patients with paroxysmal or persistent atrial fibrillation.

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.

High-sensitive cardiac troponin T as a predictor of efficacy and safety after pulmonary vein isolation using focal radiofrequency, multielectrode radiofrequency and cryoballoon ablation catheter

Introduction

Myocardial injury markers such as high-sensitive cardiac troponin T (hs-cTnT) and creatine kinase MB (CK-MB) reflects the amount of myocardial injury with ablation. The aim of the study was to identify the value of myocardial injury markers to predict outcomes after pulmonary vein isolation (PVI) using three different ablation technologies.

Methods

Consecutive patients undergoing PVI using a standard 3.5 mm irrigated-tip radiofrequency catheter (RF-group), an irrigated multielectrode radiofrequency catheter (IMEA-group) and a second-generation cryoballoon (CB-group) were analysed. Blood samples to measure injury markers were taken before and 18-24 hours after the ablation. Procedural complications were collected and standardised follow-up was performed. Logistic regression was used to identify predictors of recurrence and complications.

Results

96 patients (RF group: n=40, IMEA-group: n=17, CB-group: n=39) undergoing PVI only were analysed (82% male, age 59±10 years). After a follow-up of 12 months, atrial fibrillation (AF) recurred in 45% in the RF-group, 29% in the IMEA-group and 36% in the CB-group (p=0.492). Symptomatic pericarditis was observed in 20% of patients in the RF-group, 15% in the IMEA-group and 5% in the CB-group (p=0.131). None of the injury markers was predictive of AF recurrence or PV reconnection after a single procedure. However, hs-cTnT was identified as a predictor of symptomatic pericarditis (OR: 1.003 [1.001 to 1.005], p=0.015).

Conclusion

Hs-cTnT and CK-MB were significantly elevated after PVI, irrespective of the ablation technology used. None of the myocardial injury markers were predictive for AF recurrence or PV reconnection, but hs-cTnT release predicts the occurrence of symptomatic pericarditis after PVI.

Influence of energy source on early atrial fibrillation recurrences: a comparison of cryoballoon vs. radiofrequency current energy ablation with the endpoint of unexcitability in pulmonary vein isolation

Introduction

Comparative data of early recurrence rates of atrial fibrillation (ERAF) following second-generation cryoballoon (CB-G2) and radiofrequency current (RFC) ablation for pulmonary vein isolation (PVI) in paroxysmal AF (PAF) are rare. We randomized PAF patients into either PVI with CB-G2 (group 1) or PVI with a combined RFC-approach applying contact force (CF) with the endpoint of unexcitability (group 2) to investigate ERAF.

Methods and results

In group 1 (n = 30), CB-G2-PVI was performed. After CF-PVI in group 2 (n = 30), bipolar pacing on the ablation line and additional ablation until unexcitability was conducted. Follow-up included 48 h of in-hospital monitoring followed by 5-day Holter ECGs 1, 2, 3, 6, 12 months postablation to evaluate ERAF. Acute PVI was reached in 100% of group 2 and in 99% of group 1. Shorter procedure durations (98.0 ± 21.9 vs. 114.3 ± 18.7 min, P < 0.05) but extended fluoroscopy times (15.4 ± 3.9 vs. 10.0 ± 4.3 min, P < 0.05) were found in the CB-G2 group. Ten non-severe complications occurred (6 vs. 4 in group 1 and 2, P = 0.73). In group 2, five patients suffered from ERAF vs. seven patients in group 1 (P = 0.67). The time until the occurrence of ERAF was shorter in group 2 (1 day (q1-q3: 1-4.5)) when compared with group 1 (22 (q1-q3: 6-54) days, P = 0.025).

Conclusion

ERAF rates were equal among groups; however, they occurred earlier in the initial phase after RFC ablation when compared with CB-G2. PVI utilizing cryoablation is associated with shorter procedure durations but extended fluoroscopy time while being similarly secure.

The importance of extrapulmonary vein triggers and atypical atrial flutter in atrial fibrillation recurrence after cryoablation: Insights from repeat ablation procedures

INTRODUCTION

It has not been previously investigated whether the recurrence mechanism after cryoballoon ablation (CBA) of paroxysmal atrial fibrillation (AF) is similar to that of radiofrequency catheter ablation (RFCA). We aimed to evaluate the differences of recurrence characteristics between RFCA and CBA after the index procedure.

METHODS

A total of 210 patients were enrolled in the study, and 69 patients underwent pulmonary vein (PV) isolation using a 28-mm second-generation CBA. The control group comprising 140 patients underwent PV isolation using an open-irrigated radiofrequency ablation catheter. A total of 69 patients in the CBA group and 69 patients in the RFCA group were investigated after propensity score matching. Recurrence patterns of AF were studied in the repeated procedure.

RESULTS

During the index procedure, there was no difference in PV or non-PV triggers between the two groups. Nineteen (27.5%) patients in the CBA group and 19 (27.5%) patients in the RFCA group had recurrence after a follow-up of 11.3 ± 7 months. The Kaplan-Meier curve did not reveal significant difference in recurrence (log-rank, P = 0.364) between the two groups. In the second procedure, the CBA group had more non-PV triggers (63.6%, P = 0.009) and left atrial (LA) flutters (54.5%, P = 0.027) compared with the RFCA group (12.5% and 12.5%, respectively). The PV reconnection rates were similar between both groups.

CONCLUSIONS

There was no difference in AF recurrence after catheter ablation between CBA and RFCA, but significant increases of non-PV triggers and LA flutter during the second procedure suggest the importance of the atrial substrate in maintaining AF during the second procedure after previous CBA.

Transient manifestation of left ventricular diastolic dysfunction following ablation in patients with paroxysmal atrial fibrillation

BACKGROUND

In patients with atrial fibrillation, ablation decreases left atrial (LA) compliance, which may lead to left ventricular (LV) diastolic dysfunction. We aimed to examine serial changes in LV diastolic function after 2 ablation procedures and their related factors in patients with paroxysmal atrial fibrillation (PAF).

HYPOTHESIS

LV diastolic function is different after 2 ablation procedures.

METHODS

We enrolled 132 patients with PAF (76 males, mean age 67 years; cryoballoon [CB] ablation/radiofrequency [RF] ablation 60/72) who underwent a single ablation procedure. The transthoracic echocardiographic parameters were obtained before, 3 days after, and 6 months after ablation.

RESULTS

The afterload-related index of LV diastolic function, Ed/Ea = E/e' / (0.9 × systolic blood pressure), increased significantly at 3 days after ablation, especially after CB ablation (P <0.05), although no differences were observed in age, sex, LA size, LV size, and E/e' before ablation between CB ablation and RF ablation. Creatine kinase release after ablation was significantly higher in CB ablation than in RF ablation (P <0.001). The increment of Ed/Ea after CB ablation was positively correlated with LV ejection fraction (LVEF) before ablation (r =0.416; P <0.05). The elderly (age ≥ 75 years), females, and patients with hypertension were more likely to show impaired LV diastolic function transiently after 3 days of ablation, but the diastolic index was restored to baseline level after 6 months.

CONCLUSIONS

The increased Ed/Ea after CB ablation represented transient manifestation of underlying LV diastolic dysfunction in PAF patients with preserved LVEF with older age, female sex, and a history of hypertension.

The relationship of early recurrence of atrial fibrillation and the 3-month integrity of the ablation lesion set

Early recurrence of atrial fibrillation (ERAF) after catheter-ablation (CA) can be a transient phenomenon due to inflammation, or a harbinger of late AF recurrence due to CA lesion (re)conduction. We studied the relationship between ERAF and the 3-month CA lesions integrity. Forty one consecutive AF patients who underwent a pulmonary vein isolation (PVI), roof line (RL) and mitral isthmus line (MIL) CA were enrolled. At 3 months all patients underwent invasive assessment of the lesion set integrity irrespective of ERAF. The PVI, RL and MIL ablation was successful in 100.0%, 95.1% and 82.9% patients, respectively. At the 3-month remapping, a gap in PVI-lesion(s), RL or MIL was identified in 61.0%, 31.7% and 36.6% patients, respectively. Patients with (n = 17, 41.5%) compared to those without ERAF (n = 24) had a significantly higher rate of any PV-reconnection (88.2% vs. 41.7%), the right PV(s)-reconnection (82.5% vs. 29.2%) and the RL gap (52.9% vs. 16.7%), as well as a higher number of reconnected right PVI-segments, all p < 0.05. On multivariate analysis, only the number of reconnected right PVI-segments was associated with ERAF (OR 4.26, p = 0.004). The ERAF following PVI + RL + MIL ablation was significantly related to 3-month PV-reconnections and the presence of RL gaps.

Radiofrequency Ablation versus Cryoablation in the Treatment of Paroxysmal Atrial Fibrillation: A Meta-Analysis

Background

Pulmonary vein isolation is commonly performed using radiofrequency energy with cryoablation gaining acceptance. We performed a meta-analysis of randomized controlled trials which compared radiofrequency versus cryoablation for patients with atrial fibrillation.

Methods

A systematic search strategy identified both published and unpublished articles from inception to November 10, 2016, in multiple databases. The primary outcomes for this meta-analysis were long-term freedom from atrial fibrillation at 12-month follow-up and overall postoperative complication rates. For all included studies, the methodological quality was assessed through the Cochrane Collaboration's tool for risk of bias.

Results

A total of 247 articles were identified with eight being included in this review as they satisfied the prespecified inclusion criteria. Overall, there was no significant difference in freedom from atrial fibrillation at ≥12-month follow-up between those receiving cryoballoon and radiofrequency ablation, respectively (OR = 0.98, CI = 0.67–1.43, I² = 56%, p=0.90). Additionally, the secondary outcomes of duration of ablation, fluoroscopy time, and ablation time failed to reach significance. Cryoballoon ablation had significantly greater odds of postoperative phrenic nerve injury at 12-month follow-up.

Conclusions

Our meta-analysis suggests that cryoballoon ablation provides comparable benefits with regard to freedom from atrial fibrillation at medium-term follow-up, fluoroscopy time, ablation time, operative duration, and overall complication rate in comparison to radiofrequency ablation.

Early Recurrences During the Blanking Period after Atrial Fibrillation Ablation

Early recurrences of atrial arrhythmias (ERAA) after ablation are common and predict late recurrences and ablation failure.However,becausea proportion of patients with ERAA will have no subsequent arrhythmias after the blanking period, consensus guidelines recommend against immediate repeat ablation for ERAA episodes occurring during the first 3 months post-ablation. In this review, we summarize the predictors, significance, and treatment of ERAA after AF ablation.

Cryoballoon Ablation for Atrial Fibrillation: a Comprehensive Review and Practice Guide

The cryoballoon was invented to achieve circumferential pulmonary vein isolation more efficiently to compliment the shortcomings of point-by-point ablation by radiofrequency ablation (RFA). Its efficacy and safety were shown to be comparable to those of RFA, and the clinical outcomes have improved with the second-generation cryoballoon. The basic biophysics, implemental techniques, procedural recommendations, clinical outcomes, and complications of the cryoballoon are presented in this practical and systematic review.

Circulatory Dynamics During Pulmonary Vein Isolation Using the Second-Generation Cryoballoon

BACKGROUND

Circulatory dynamics change during pulmonary vein (PV) isolation using cryoballoons. This study sought to investigate the circulatory dynamics during cryoballoon-based PV isolation procedures and the contributing factors.

METHODS AND RESULTS

This study retrospectively included 35 atrial fibrillation patients who underwent PV isolation with 28-mm second-generation cryoballoons and single 3-minute freeze techniques. Blood pressures were continuously monitored via arterial lines. The left ventricular function was evaluated with intracardiac echocardiography throughout the procedure in 5 additional patients. Overall, 126 cryoapplications without interrupting freezing were analyzed. Systolic blood pressure (SBP) significantly increased during freezing (138.7±28.0 to 148.0±27.2 mm Hg, P<0.001) and sharply dropped (136.3±26.0 to 95.0±17.9 mm Hg, P<0.001) during a mean of 21.0±8.0 seconds after releasing the occlusion during thawing. In the multivariate analyses, the left PVs (P=0.008) and lower baseline SBP (P<0.001) correlated with a larger SBP rise, whereas a higher baseline SBP (P<0.001), left PVs (P=0.017), lower balloon nadir temperature (P=0.027), and female sex (P=0.045) correlated with larger SBP drops. These changes were similarly observed regardless of preprocedural atropine administration and the target PV order. PV occlusions without freezing exhibited no SBP change. PV antrum freezing without occlusions similarly increased the SBP, but the SBP drop was significantly smaller than that with occlusions (P<0.001). The SBP drop time-course paralleled the left ventricular ejection fraction increase (66.8±8.1% to 79.3±6.7%, P<0.001) and systemic vascular resistance index decrease (2667±1024 to 1937±513 dynes-sec/cm2 per m2, P=0.002).

CONCLUSIONS

With second-generation cryoballoon-based PV isolation, SBP significantly increased during freezing owing to atrial tissue freezing and dropped sharply after releasing the occlusion, presumably because of the peripheral vascular resistance decrease mainly by circulating chilled blood.

Autonomic nervous system modulation and clinical outcome after pulmonary vein isolation using the second-generation cryoballoon

BACKGROUND

The intrinsic cardiac autonomic nervous system (ANS) plays a significant role in atrial fibrillation (AF) mechanisms. This study evaluated the incidence and impact of intraprocedural vagal reactions and ANS modulation by pulmonary vein isolation (PVI) using second-generation cryoballoons on outcomes.

METHODS

One hundred three paroxysmal AF patients underwent PVI with one 28-mm second-generation balloon. The median follow-up was 15.0 (12.0-18.0) months. ANS modulation was defined as a >20% cycle length decrease on 3-minute resting electrocardiograms at 1, 3, 6, and 12 months postindex procedure relative to baseline if sinus rhythm was maintained.

RESULTS

Marked sinus arrests/bradycardia and atrioventricular block (intraprocedural vagal reaction) occurred in 14 and 2 patients, and all sinus arrest/bradycardia occurred in 44 patients with left superior pulmonary veins (PVs) targeted before right PVs. ANS modulation was identified in 66 of 95 (69.5%) patients, and it persisted 12-month postprocedure in 36 (37.9%) patients. Additional β-blocker administration was required in 9 patients for sinus tachycardia. ANS modulation was similarly observed in patients with and without intraprocedural vagal reactions (P = 0.443). Forty-eight (46.6%) patients experienced early recurrences, and the single procedure success at 12 months was 72.7%. Neither intraprocedural vagal reactions nor ANS modulation predicted AF freedom within or after the blanking period. Thirty-three patients underwent second procedures, and reconnections were detected in 39 of 130 (30.0%) PVs among 23 (69.7%) patients. The incidence of reconnections was similar in patients with and without ANS modulation.

CONCLUSIONS

Increased heart rate persisted in 37.9% of patients even at 12-month post-second-generation cryoballoon PVI. Neither intraprocedural vagal reactions nor increased heart rate predicted a single procedure clinical outcome.

Mechanisms and clinical significance of early recurrences of atrial arrhythmias after catheter ablation for atrial fibrillation

Early recurrence of atrial arrhythmias (ERAA) after ablation is common and strongly predicts late recurrences and ablation failure. However, since arrhythmia may eventually resolve in up to half of patients with ERAA, guidelines do not recommend immediate reintervention for ERAA episodes occurring during a 3-mo post-ablation blanking period. Certain clinical demographic, electrophysiologic, procedural, and ERAA-related characteristics may predict a higher likelihood of long-term ablation failure. In this review, we aim to discuss potential mechanisms of ERAA, and to summarize the clinical significance, prognostic implications, and treatment options for ERAA.