Second generation cryoballoon ablation for persistent atrial fibrillation: an updated meta-analysis

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.

Radiofrequency versus cryoballoon catheter ablation in patients with persistent atrial fibrillation: A randomized trial

INTRODUCTION

Patients with persistent atrial fibrillation (AF) represent a challenging population for rhythm control therapies. Catheter ablation (CA) with pulmonary vein isolation (PVI) is an effective treatment option for the reduction of the arrhythmic burden. Data regarding the comparability between radiofrequency (RF) and cryoballoon ablation (CRYO) in persistent AF are limited.

METHODS

This is a prospective, randomized, single-center study designed to compare the efficacy in terms of rhythm control between RF and CRYO in persistent AF. Eligible participants were randomized 2:1 in two arms: RF and CRYO. The primary endpoint of the study was arrhythmia relapse in the early postprocedural period (first 3 months) and in the middle term follow-up (3 months to 12 months). Secondary endpoints included procedure duration, fluoroscopy time, and complications.

RESULTS

A total of 199 patients participated in the study (133 patients in the RF arm, 66 in the CRYO arm). No statistically significant difference occurred between the two groups regarding the primary endpoint (recurrences ≤3 months: 35.5% RF vs. 37.9% CRYO, p .755, recurrences >3 months: 26.3% RF vs. 27.3% CRYO, p .999). From the secondary endpoints, CRYO was a procedure of significantly shorter duration (75.15 ± 17.21 in CRYO vs. 136.6 ± 43.33 in RF group, p < .05).

CONCLUSION

CRYO and RF ablation appear to be equally effective for rhythm control in patients with persistent AF. CRYO ablation is advantageous in terms of procedure duration.

Left atrial appendage volume is an independent predictor of atrial arrhythmia recurrence following cryoballoon pulmonary vein isolation in persistent atrial fibrillation

Purpose

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation in persistent AF (persAF), and cryoballoon PVI emerged as an initial ablation strategy. Symptomatic atrial arrhythmia recurrence following successful PVI in persAF is observed more frequently than in paroxysmal AF. Predictors for arrhythmia recurrence following cryoballoon PVI for persAF are not well described, and the role of left atrial appendage (LAA) anatomy is uncertain.

Methods

Patients with symptomatic persAF and pre-procedural cardiac computed tomography angiography (CCTA) images undergoing initial second-generation cryoballoon (CBG2) were enrolled. Left atrial (LA), pulmonary vein (PV) and LAA anatomical data were assessed. Clinical outcome and predictors for atrial arrhythmia recurrence were evaluated by univariate and multivariate regression analysis.

Results

From May 2012 to September 2016, 488 consecutive persAF patients underwent CBG2-PVI. CCTA with sufficient quality for measurements was available in 196 (60.4%) patients. Mean age was 65.7 ± 9.5 years. Freedom from arrhythmia was 58.2% after a median follow-up of 19 (13; 29) months. No major complications occurred. Independent predictors for arrhythmia recurrence were LAA volume (HR 1.082; 95% CI, 1.032 to 1.134; p = 0.001) and mitral regurgitation ≥ grade 2 (HR, 2.49; 95% CI 1.207 to 5.126; p = 0.013). LA volumes ≥110.35 ml [sensitivity: 0.81, specificity: 0.40, area under the curve (AUC) = 0.62] and LAA volumes ≥9.75 ml (sensitivity: 0.56, specificity 0.70, AUC = 0.64) were associated with recurrence. LAA-morphology, classified as chicken-wing (21.9%), windsock (52.6%), cactus (10.2%) and cauliflower (15.3%), did not predict outcome (log-rank, p = 0.832).

Conclusion

LAA volume and mitral regurgitation were independent predictors for arrhythmia recurrence following cryoballoon ablation in persAF. LA volume was less predictive and correlated with LAA volume. LAA morphology did not predict the clinical outcome. To improve outcomes in persAF ablation, further studies should focus on treatment strategies for persAF patients with large LAA and mitral regurgitation.

Best Practice Guide for Cryoballoon Ablation in Atrial Fibrillation: The Compilation Experience of More than 1000 Procedures

Nowadays, the cryoballoon (CB) constitutes an established alternative to radio frequency (RF) ablation for pulmonary vein isolation (PVI), which offers the possibility to isolate the PVs with a single application. Since the introduction of the second-generation CB, we prospectively collected our data to optimize the procedure on >1000 consecutive patients who underwent CB PVI performed in our center. It is expected that subsequent guidelines will suggest first-line PVI through CB in patients with paroxysmal AF with a class I indication. Indeed, in the long-term follow-up (36 months) of the EARLY-AF trial, CB had a lower incidence of persistent atrial fibrillation episodes compared to the anti-arrhythmic drugs group. We now review the current best practices in an effort to drive consistent outcomes and minimize complications. PV isolation through CB is the most studied single-shot technique for atrial fibrillation ablation, having shown the potential to alter the natural history of the arrhythmia. Several procedural tips and tricks can improve procedural flow and effectiveness. In the present article we provided not only technical details but measurable biophysical parameters that can reliably guide the operator into achieving the best outcome for his patients.

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.

Persistent Atrial Fibrillation in Elderly Patients: Limited Efficacy of Pulmonary Vein Isolation

(1) Background: Cryoballoon pulmonary vein isolation (cryoPVI) is established for symptomatic paroxysmal atrial fibrillation (AF) treatment, but its value in persistent AF is less clear. In particular, limited data are available on its efficacy in elderly patients (≥75 years) with persistent AF. Age is an important modifier of AF progression and represents a risk-factor for AF recurrence. (2) Methods: Prospective, single-center observational study to evaluate the impact of age on efficacy and safety of cryoPVI in elderly patients. Primary efficacy endpoint was symptomatic AF recurrence after 90-day blanking period. Primary safety endpoints were death from any cause, procedure-associated complications or stroke/transient ischemic attack. Median follow-up was 17 months (range 3−24). (3) Results: We included 268 patients with persistent AF (94 ≥ 75 years of age). Multivariate Cox regression analysis identified age as the only independent factor influencing AF recurrence in the overall cohort (p = 0.006). To minimize confounding bias in efficacy and safety analysis of cryoPVI, we matched younger and elderly patients with respect to baseline characteristics. At 24 months, primary efficacy endpoint occurred in 13/69 patients <75 years and 31/69 patients ≥75 years of age (24 months Kaplan−Meier event-rate estimates, HR 0.34; 95% CI, 0.19 to 0.62; log-rank p = 0.0004). No differences were observed in the occurrence of safety end points. (4) Conclusions: Elderly (≥75 years) patients with persistent AF undergoing cryoPVI had an approximately threefold higher risk of symptomatic AF recurrence than matched younger patients. Accordingly, other treatment modalities may be evaluated in this population.

The Long-Term Outcomes of Ablation With Vein of Marshall Ethanol Infusion vs. Ablation Alone in Patients With Atrial Fibrillation: A Meta-Analysis

Background

The long-term outcomes of ablation with vein of Marshall ethanol infusion (VOM-ABL) compared with ablation alone in patients with atrial fibrillation (AF) remains elusive. We aimed to explore whether VOM-ABL showed better long-term benefits and screen the potential determinants of outcome impact of VOM-ABL procedure.

Methods

PubMed, Cochrane Library, Web of Science, and Embase were searched up to 1st September 2021. Studies comparing the long-term (one-year or longer) outcomes between VOM-ABL and ablation alone were included. Subgroup analysis identified potential determinants for VOM-ABL procedure.

Results

Compared with ablation alone, VOM-ABL was associated with a significantly higher rate of long-term freedom from AF/AT (risk ratio [RR], 1.28; 95% confidence interval [CI], 1.12–1.47; p = 0.00) and successful mitral isthmus (MI) block (RR, 1.52; 95% CI, 1.16–1.99; p = 0.00), whereas, there was no significant difference in pericardial effusion, stroke/transient ischemic attack (TIA), and all-cause death. Subgroup analysis identified two significant treatment-covariate interactions: one was ablation strategy subgroup (pulmonary vein isolation plus linear and/or substrate ablation [PVI+]; RR, 1.41; 95% CI, 1.27–1.56 vs. PVI; RR, 1.05; 95% CI, 0.92–1.19, p = 0.00 for interaction) for freedom from AF/AT, while the other was VOM-ABL group sample size subgroup (≥ 100; RR, 1.98; 95% CI, 1.24–3.17 vs. <100; RR, 1.20; 95% CI, 1.10–1.30, p = 0.04 for interaction) for MI block.

Conclusions

This meta-analysis demonstrates that VOM-ABL has superior efficacy and comparable safety over ablation alone in AF patients with long-term follow-up. Moreover, PVI+ and VOM-ABL group sample size ≥ 100 may be associated with a great impact on freedom from AF/AT and MI block, respectively.

Cryoballoon Ablation for Persistent and Paroxysmal Atrial Fibrillation: Procedural Differences and Results from the Spanish Registry (RECABA)

Introduction: Cryoballoon ablation (CBA) has become a standard treatment for paroxysmal atrial fibrillation (PaAF) but limited data is available for outcomes in patients with persistent atrial fibrillation (PeAF). Methods: We analyzed the first 944 patients included in the Spanish Prospective Multi-center Observation Post-market Registry to compare characteristics and outcomes of patients undergoing CBA for PeAF versus PaAF. Results: A total of 944 patients (57.8 ± 10.4 years; 70.1% male) with AF (27.9% persistent) were prospectively included from 25 centers. PeAF patients were more likely to have structural heart disease (67.7 vs. 11.4%; p < 0.001) and left atrium dilation (72.6 vs. 43.3%; p < 0.001). CBA of PeAF was less likely to be performed under general anesthesia (10.7 vs. 22.2%; p < 0.001), with an arterial line (32.2 vs. 44.6%; p < 0.001) and assisted transeptal puncture (11.9 vs. 17.9%; p = 0.025). During an application, PeAF patients had a longer time to −30 °C (35.91 ± 14.20 vs. 34.93 ± 12.87 s; p = 0.021) and a colder balloon nadir temperature during vein isolation (−35.04 ± 9.58 vs. −33.61 ± 10.32 °C; p = 0.004), but received fewer bonus freeze applications (30.7 vs. 41.1%; p < 0.001). There were no differences in acute pulmonary vein isolation and procedure-related complications. Overall, 76.7% of patients were free from AF recurrences at 15-month follow-up (78.9% in PaAF vs. 70.9% in PeAF; p = 0.09). Conclusions: Patients with PeAF have a more diseased substrate, and CBA procedures performed in such patients were more simplified, although longer/colder freeze applications were often applied. The acute efficacy/safety profile of CBA was similar between PaAF and PeAF patients, but long-term results were better in PaAF patients.

Cryoballoon Ablation Strategy in Persistent Atrial Fibrillation

Background: Cryoballoon ablation is established for pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (AF). The objective was to evaluate CBA strategy in consecutive patients with persistent AF in the initial AF ablation procedure.

Material and Methods: Prospectively, patients with symptomatic persistent AF scheduled for AF ablation all underwent cryoballoon PVI. Technical enhancements, laboratory management, safety, single-procedure outcome, predictors of recurrence, and durability of PVI were evaluated.

Results: From 2007 to 2020, a total of 1,140 patients with persistent AF, median age 68 years, underwent cryoballoon ablation (CBA). Median left atrial (LA) diameter was 45 mm (interquantile range, IQR, 8), and Congestive heart failure, Hypertension, Age ≥75 years (doubled), Diabetes mellitus, prior Stroke or TIA or thromboembolism (doubled), Vascular disease, Age 65 to 74 years, Sex category (CHA₂DS₂-VASc) score was 3. Acute isolation was achieved in 99.6% of the pulmonary veins by CBA. Median LA time and median dose area product decreased significantly over time (p < 0.001). Major complications occurred in 17 (1.5%) patients including 2 (0.2%) stroke/transitory ischemic attack (TIA), 1 (0.1%) tamponade, relevant groin complications, 1 (0.1%) significant ASD, and 4 (0.4%) persistent phrenic nerve palsy (PNP). Transient PNP occurred in 66 (5.5%) patients. No atrio-esophageal fistula was documented. Five deaths (0.4%), unrelated to the procedure, occurred very late during follow-up. After initial CBA, arrhythmia recurrences occurred in 46.6% of the patients. Freedom from atrial arrhythmias at 1-, and 2-year was 81.8 and 61.7%, respectively. Independent predictors of recurrence were LA diameter, female sex, and use of the first cryoballoon generation. Repeat ablations due to recurrences were performed in 268 (23.5%) of the 1,140 patients. No pulmonary vein (PV) reconduction was found in 49.6% of the patients and 73.5% of PVs. This rate increased to 66.4% of the patients and 88% of PVs if an advanced cryoballoon was used in the first AF ablation procedure.

Conclusion: Cryoballoon ablation for symptomatic persistent AF is a reasonable strategy in the initial AF ablation procedure.

Cryoballoon vs. radiofrequency catheter ablation: insights from NOrwegian randomized study of PERSistent Atrial Fibrillation (NO-PERSAF study)

Aims

Pulmonary vein isolation (PVI) is still regarded as a cornerstone for treatment of persistent atrial fibrillation (AF). This study evaluated the effectiveness of PVI performed with cryoballoon ablation (CBA) in comparison with radiofrequency ablation (RFA) in patients with persistent AF.

Methods and results 

A total of 101 patients with symptomatic persistent AF were enrolled and randomized (1:1) to CBA or RFA groups and followed up for 12 months. The primary endpoint was any documented recurrent atrial tachyarrhythmia (ATA) lasting longer than 30 s following a 3-month blanking period. Secondary endpoints were procedure-related complications, procedure and ablation duration, and fluoroscopy time. The ATA-free survival curves were estimated by Kaplan–Meier method and analysed by the log-rank test. According to intention-to-treat analysis, freedom from ATA was achieved in 36 out of 52 patients in the CBA group and 30 out of 49 patients in the RFA group (69.2% vs. 61.2%, P = 0.393). No difference in AF recurrence was found between the two groups (27.5% in CBA vs. 38.0% in RFA, P = 0.258), and less atrial flutter recurrence was documented in the CBA group compared with the RFA group (3.9% vs. 18.0%, P = 0.020). The procedure and ablation duration were significantly shorter in the CBA group (160 ± 31 vs. 197 ± 38 min, P < 0.0001; 36.7 ± 9.5 vs. 55.3 ± 16.7 min, P < 0.0001). There was no difference regarding fluoroscopy time (21.5 ± 7.8 vs. 23.4 ± 11.2 min, P > 0.05).

Conclusion 

Compared with RFA, PVI performed by CBA led to shorter procedure and ablation duration, with less atrial flutter recurrence and similar freedom from ATA at 12-month follow-up.

The Effect of Diabetes Mellitus on the Recurrence of Atrial Fibrillation after Ablation

Diabetes mellitus (DM) plays a crucial role in the regulation of atrial fibrillation (AF). This study aimed to evaluate the outcome of pulmonary vein isolation (PVI) using a single-shot device in patients with AF and DM. A total of 531 consecutive patients undergoing initial cryoballoon (CB)-guided PVI were evaluated. Two hundred eighty-one patients (53%) suffered from paroxysmal AF (PAF; mean age 51 ± 23.2 years, 26% female), 250 patients (48%) from persistent AF (PERS; 64 ± 10.0 years old, 30% female) and 80 patients (15%) were diagnosed with coincidental DM (68 ± 19.6 years old, 30% female). Follow-up visits were performed at 3, 6 and 12 months including 7-day Holter ECGs. Primary endpoint was the first documented recurrence of atrial tachyarrhythmia. AF recurrence occurred in 26% (140 patients). PAF patients with DM presented with a significantly higher risk for arrhythmia recurrence (Kaplan Meier analysis; Log rank p < 0.001 *). Multivariate analyses found DM to be an independent predictor (IP) for AF recurrence (p = 0.009 *, hazard ratio (HR) 4.363, confidence interval (CI) 1.456–13.074). In PERS, DM was associated with a 43% increase in AF recurrence (p = 0.320, HR 1.427, CI 0.707–2.879). DM has relevant effects on AF recurrence after PVI-only ablation approaches for AF. Major differences were observed in PAF as DM seems to favor the development of individual arrhythmia substrate, which is usually not yet present in PAF. In PERS, DM effects are less pronounced as individual fibrosis has already developed. Thus, personalized paths addressing individual arrhythmia substrates are needed in this specific cohort of patients.

Anatomical targets and expected outcomes of catheter-based ablation of atrial fibrillation in 2020

Anatomical-based approaches, targeting either pulmonary vein isolation (PVI) or additional extra PV regions, represent the most commonly used ablation treatments in symptomatic patients with atrial fibrillation (AF) recurrences despite antiarrhythmic drug therapy. PVI remains the main anatomical target during catheter-based AF ablation, with the aid of new technological advances as contact force monitoring to increase safety and effective radiofrequency (RF) lesions. Nowadays, cryoballoon ablation has also achieved the same level of scientific evidence in patients with paroxysmal AF undergoing PVI. In parallel, electrical isolation of extra PV targets has progressively increased, which is associated with a steady increase in complex cases undergoing ablation. Several atrial regions as the left atrial posterior wall, the vein of Marshall, the left atrial appendage, or the coronary sinus have been described in different series as locations potentially involved in AF initiation and maintenance. Targeting these regions may be challenging using conventional point-by-point RF delivery, which has opened new opportunities for coadjuvant alternatives as balloon ablation or selective ethanol injection. Although more extensive ablation may increase intraprocedural AF termination and freedom from arrhythmias during the follow-up, some of the targets to achieve such outcomes are not exempt of potential severe complications. Here, we review and discuss current anatomical approaches and the main ablation technologies to target atrial regions associated with AF initiation and maintenance.

Two-Year Outcome From Combining Cryoballoon Ablation and Left Atrial Appendage Closure: CLACBAC Study

Objective: Catheter ablation combined with left atrial appendage closure (LAAC) has emerged as a promising strategy for atrial fibrillation (AF) patients at high risk for stroke or with contraindications for oral anticoagulants (OACs). But the evidence for the long-term safety and efficacy of a combined procedure using cryoballoon ablation (CBA) with LAAC is still insufficient.

Methods: From October 2015 to December 2017, a total of 76 consecutive non-valvular, drug-refractory AF patients who underwent a combined procedure of CBA and LAAC are included. Peri- and post-procedural safety and efficacy were evaluated through scheduled follow-ups and transesophageal echocardiography (TEE).

Results: A total of 74 patients (97.4%) underwent the combined procedure and achieved instant pulmonary vein isolation and satisfactory LAAC. With a mean follow-up time of 23.7 ± 11.0 months, the recurrence of atrial arrhythmia was recorded in 35 patients (48.0%). In addition, a survival analysis shows a non-significant higher recurrence in persistent AF (p = 0.48). The overall OAC withdrawal rate was 97.2%, and one patient (1.4%) had a lethal hemorrhagic stroke while on single antiplatelet therapy. For safety concerns, the overall mortality was 2.7%, which resulted from one case of myocardial infarction on OAC and one hemorrhagic stroke, as mentioned. No other major hemorrhagic events occurred. Among the 72 patients (94.7%) who underwent TEE, one patient (1.4%) had device-related thrombosis and one patient (1.4%) had prominent residual flow (over 3 mm). Both were prescribed long-term OACs without severe complications occurring.

Conclusions: Combining CBA with LAAC in a single procedure achieved considerable long-term safety and efficacy, providing a promising strategy for AF management.

Intraprocedural Conversion Efficacy of Intravenous Nifekalant Administration for Persistent Atrial Fibrillation after Pulmonary Vein Isolation

The aim of this study was to prospectively assess the efficacy, safety, and predictive effect of intravenous nifekalant administration for persistent atrial fibrillation (PerAF) after pulmonary vein isolation (PVI) with second-generation cryoballoon ablation (CBA) on 1-year atrial tachyarrhythmia (ATa) -free survival by examining the pharmacological conversion rate.One hundred and two drug-refractory, consecutive PerAF patients undergoing PVI were enrolled in this prospective observational study. After PVI, nifekalant (50 mg) was given followed by 30 minutes of observation and no further intervention. PerAF was successfully converted to sinus rhythm (SR) in 60 patients (58.8%) after a median time of 7.75 (4.13-12) minutes (group N). In the remaining 42 patients (41.2%) (group C), PerAF was successfully converted to SR by external electrical cardioversion. Nonsustained ventricular tachycardia occurred in 1 patient in group N. The left atrial volume (LAV) in group C was larger than that in group N (128.2 ± 28.2 versus 111.8 ± 24.5 mL, P = 0.002). Phrenic nerve injury occurred in 4 of 102 patients (3.9%). No other complications occurred during the procedure or within the 1-year follow-up period. At the 1-year follow-up, after a 3-month blanking period (BP), ATa-free survival during 1-year follow-up in group C was significantly lower than that in group N (50.0% versus 71.7%, P = 0.026), and the overall ATa-free survival rate was 62.7%. Two patients in group C and 4 patients in group N underwent a second procedure with radiofrequency catheter ablation. Multivariate Cox regression analysis demonstrated that unsuccessful conversion to SR (P = 0.025), ATa relapse during the BP (P = 0.000), and larger LAV (P = 0.016) were independent predictors of ATa recurrence at the 1-year follow-up.In conclusion, at the 1-year follow-up, the ATa-free survival rate after PVI with CBA for PerAF patients was 62.7%, and successful conversion to SR with nifekalant could serve as a clinical predictor of reduced ATa recurrence.

Balloon-Based Ablation Technologies

Pulmonary vein isolation (PVI) is widely accepted as the mainstay of interventional treatment of atrial fibrillation. Ablation with radiofrequency (RF) point-by-point catheters is highly operator dependent and may fail because of ineffective lesions or gaps. Several balloon-based catheter ablation technologies have emerged as an alternative to effect PVI. Cryoballoon ablation is widely used, and current iterations of the technology show comparable acute and long-term efficacy to RF ablation. Techniques such as time to isolation have emerged to improve efficacy and safety. Laser balloon is a highly compliant variably sized balloon that has been validated as an effective strategy for PVI.

Conversion of atrial fibrillation to sinus rhythm during cryoballoon ablation: A favorable and not unusual phenomenon during second-generation cryoballoon pulmonary vein isolation

BACKGROUND

The prevalence and the clinical impact of conversion of atrial fibrillation (AF) to sinus rhythm (SR) during cryoballoon ablation (CB-A) are unknown.

OBJECTIVE

The purpose of this study was to evaluate the prevalence of restoration of SR during CB-A and the clinical impact of this phenomenon.

METHODS

Between January 2012 and September 2018, all patients who experienced conversion of AF to SR during CB-A were included. This group was subsequently matched for gender, age, type of AF, diagnosis-to-ablation time, and left atrial size with patients who underwent CB-A and did not experienced conversion of AF to SR. After discharge, patients were scheduled for follow-up visits at 1, 3, 6, and 12 months and 24 hours Holter recordings were obtained at each follow-up visit. All documented AF episodes of >30 seconds were considered as recurrence. A 3 month post-procedural blanking period (BP) was applied.

RESULTS

A total of 1559 patients underwent pulmonary veins isolation by CB-A between January 2012 and September 2018; among them, 58 patients (3.7%) experienced restoration of SR during CB-A. In total, 53 patients (41 males [77.3%], mean age 61.4 ± 13.3 years) were included in the case group. During CB-A, restoration of SR occurred more frequently during right-side PVs applications (right inferior pulmonary vein 39.6%, right superior pulmonary vein 30.2%). If considering a BP, at 2 year follow-up, freedom from recurrences was 86.5% in the case group and 68.0% in the control group (P = .036).

CONCLUSION

Conversion of AF to SR is a favorable and relatively frequent phenomenon during cryoballoon pulmonary vein isolation ablation.

Association of Obesity Measures with Atrial Fibrillation Recurrence After Cryoablation in Patients with Paroxysmal Atrial Fibrillation

BACKGROUND Obesity increases the risk of atrial fibrillation (AF) recurrence after ablation. This study explored the relationship between various obesity indexes and risk of recurrence after cryoablation of paroxysmal AF (PAF). MATERIAL AND METHODS Our prospective study included 100 patients with PAF who underwent first cryoablation. Physical examination and fasting blood lipids levels were measured at baseline. Seven obesity indexes were determined: body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), waist-hip ratio (WHR), cardiometabolic index (CMI), lipid accumulation product (LAP), and body adiposity index (BAI). AF recurrence was confirmed by electrocardiograms and Holter monitor at follow-up visits after the initial 3-month blanking period. Receiver operating characteristic (ROC) curves were drawn to assess the abilities of obesity indicators in predicting AF recurrence. Multivariable Cox regression analysis was used to examine independent predictors of AF recurrence. RESULTS During a mean follow-up of 13.4 months, 31 patients (31.0%) had recurrent AF. Patients with recurrence had higher BMI, WC, WHtR, LAP, and BAI compared with those without recurrence. ROC analysis indicated the potential predictive value of BAI with an AUC of 0.657 (95% confidence interval [CI]: 0.534-0.779), followed by WC, WHtR, LAP, and BMI (all P<0.05). Diagnosis-to-ablation time (HR 1.034, 95% CI: 1.002-1.068), left atrial diameter (HR 1.147, 95% CI: 1.026-1.281), and WC (HR 1.026, 95% CI: 1.000-1.053) were independent predictive factors for AF recurrence after multivariable adjustment. CONCLUSIONS In this study population, WC appears to be a potential indicator for the prediction of recurrence in patients with PAF after cryoablation.

Pulmonary vein isolation and beyond: Predictive value of vagal reactions in second-generation cryoballoon ablation for the outcome of persistent atrial fibrillation

BACKGROUND

Cryoballoon ablation (CBA) is gaining increasing acceptance in the treatment of persistent (per) atrial fibrillation (AF). The cardiac autonomic nervous system plays a pivotal role in the regulation of AF.

OBJECTIVE

We evaluated the impact of vagal reactions (VRs), as a surrogate marker for autonomic nervous system modulation, on the outcome of CBA in patients (pts) with perAF.

METHODS

A total of 250 consecutive pts (mean age 63.9 ± 10.0 years; 175 pts, 70% male) undergoing primary second-generation CBA for perAF were studied. VRs were defined as bradycardia <40 beats/min, asystole, or higher-degree atrioventricular block. Follow-up visits at 3, 6, and 12 months included 7-day Holter electrocardiograms.

RESULTS

VRs were recorded in 61 pts (24%). These pts showed a significantly reduced recurrence rate of AF (5%) than did those without VRs (log-rank, P < .01). Univariate Cox regression analyses confirmed VRs as a strong predictor of AF-free survival (hazard ratio [HR] 0.10; P < .01). Female sex (HR 1.71; P = .02), preprocedural tachycardia (HR 1.01; P = .01), and AF (HR 1.75; P = .01) before CBA at admission were revealed as predictors of AF recurrence. Multivariate regression model calculation solely identified VRs (HR 0.11; 95% confidence interval 0.03-0.34; P < .01) and male sex (HR 0.57; 95% confidence interval 0.36-0.89; P = .01) as independent predictors of AF-free survival.

CONCLUSION

VR is an independent predictor of AF-free survival after CBA for perAF.

Cryoablation for persistent and longstanding persistent atrial fibrillation: results from a multicentre European registry

Aims

Although cryoballoon pulmonary vein isolation is a well-established treatment for paroxysmal atrial fibrillation (AF), it’s role in persistent AF is unclear. We examined procedural success and long-term outcomes of cryoablation in persistent and longstanding persistent AF.

Methods and results

International multicentre registry from three UK and eight European centres. Consecutive patients undergoing cryoablation for persistent AF included. Procedural data, complications, and follow-up were prospectively recorded. Patients were followed-up at 3, 6, and 12 months with an electrocardiogram with open access to arrhythmia nurses thereafter. Ambulatory monitoring was dictated by symptoms. Success was defined as freedom from AF or atrial tachycardia lasting &gt;30 s off antiarrhythmic drugs (AADs). Six hundred and nine consecutive cryoablation procedures. Mean procedure and fluoroscopy times were 95 ± 65 and 13 ± 10 min. Single procedure success rates were 368/602 (61%) off AADs over a median of 2.4 (1.0–4.0) years. Arrhythmia-free survival off AADs was 64% and 57% for persistent and longstanding persistent AF at 24 months of follow-up (P = 0.02). Rate of repeat ablations was 20% in persistent and 32% in longstanding persistent AF (P = 0.006). Cox regression analyses showed a significant association between duration of AF and left atrial diameter and arrhythmia recurrence [hazard ratio (HR) 1.05, P-value 0.01 and HR 1.02, P-value 0.004].

Conclusion

Cryoablation for persistent AF is safe, fast and has good outcomes at long-term follow-up. Cryoablation is reasonable as a first line option for these patients. Short procedure times may help increase capacity of cardiac units to meet the rising demand for AF ablation. Randomised control trials are needed to compare outcomes with different techniques.

Ablation, rate or rhythm control strategies for patients with atrial fibrillation: how do they affect mid-term clinical outcomes?

BACKGROUND

Transcatheter ablation (Abl) of atrial fibrillation (AF) is regarded as the best therapeutic solution for severely symptomatic patients, in whom at least one antiarrhythmic drug has been tested.

METHODS

In the present retrospective study, 175 cases of paroxysmal, persistent or long-lasting persistent AF have been gathered, and grouped depending on therapeutic approach: Abl, isolated or followed by chronic use of antiarrhythmics (N.=74), drug treatment for rate control strategy (N.=60), and drug treatment for rhythm control strategy (N.=41). The effects respectively exerted by the three treatment modalities on the primary endpoint, namely a composite of death, disabling stroke, severe bleeding and cardiac arrest, have been compared through a median follow-up of 20 months (interquartile range: 18-24 months) using the Cox proportional-hazards regression analysis. Further exposure variables were hypertension, the A-P diameter of the left atrium, the left ventricular ejection fraction and AF relapses.

RESULTS

The rhythm control strategy and AF recurrences during the follow-up were associated with increased risk of the primary composite endpoint as documented by the Cox model (for the former, hazard ratio [HR]: 3.3159; 95% CI: 1.5415 to 7.1329; P=0.0023; for the latter, HR: 1.0448; 95% CI: 1.0020 to 1.0895; P=0.0410). Even hypertension was associated with an increased risk (HR: 1.1040; 95% CI: 1.0112 to 1.9662; P=0.0477). On the contrary, a rate control strategy predicted a decreased risk of experiencing the primary endpoint (HR: 0.0711; 95% CI: 0.0135 to 0.3738; P=0.0019) while Abl did not exert a statistically significant effect on the same outcome.

CONCLUSIONS

AF ablation is able to decrease the arrhythmic episodes but does not offer a statistically significant protection against the composite of death, disabling stroke, severe bleeding and cardiac arrest in the mid-term follow-up.

Association between atrial fibrillation and Helicobacter pylori

The connection between atrial fibrillation (AF) and H. pylori (HP) infection is still matter of debate. We performed a systematic review and metanalysis of studies reporting the association between AF and HF. A systematic review of all available reports in literature of the incidence of HP infection in AF and comparing this incidence with subjects without AF were analysed. Risk ratio and 95% confidence interval (CI) and risk difference with standard error (SE) were the main statistics indexes. Six retrospective studies including a total of 2921 were included at the end of the selection process. Nine hundred-fifty-six patients (32.7%) were in AF, whereas 1965 (67.3%) were in normal sinus rhythm (NSR). Overall, 335 of 956 patients with AF were HP positive (35%), whereas 621 were HP negative (65%). In addition, 643 of 1965 NSR patients (32.7%) were HP positive while 1,322 were negative (67.3%; Chi-square 2.15, p = 0.21). The Cumulative Risk Ratio for AF patients for developing an HP infection was 1.19 (95% CI 1.08-1.41). In addition, a small difference risk towards AF was found (0.11 [SE = 0.04]). Moreover, neither RR nor risk difference were influenced by the geographic area at meta-regression analysis. Finally, there was a weak correlation between AF and HP (coefficient = 0.04 [95% CI -0.01-0.08]). We failed to find any significant correlation between H. pylori infection and AF and, based on our data, it seems unlikely than HP can be considered a risk factor for AF. Further larger research is warranted.

Mapping and Imaging in Non-paroxysmal AF

Despite intense research efforts, maintenance of sinus rhythm in patients with non-paroxysmal AF remains challenging with suboptimal outcomes. A major limitation to the success of current ablation-based treatments is that our understanding of AF pathophysiology is incomplete. Advances in imaging and mapping tools have been reported to improve ablation outcomes. However, the role of these new approaches on the clinical care of patients with AF remains to be validated and better understood before wide adoption can occur. This article reviews the current techniques of imaging and mapping that can be applied in the management of patients with non-paroxysmal AF with a focus on their relevance to catheter ablation. Future applications and opportunities for new knowledge are also discussed.

Long-term development of radiation exposure, fluoroscopy time and contrast media use in daily routine in cryoballoon ablations after implementation of intracardiac echocardiography and other radioprotective measures: experiences from a large single-centre cohort

PURPOSE

The concern of higher radiation exposure during cryoballoon ablation (CBA) compared with radiofrequency ablation for atrial fibrillation (AF) was raised before. Previously, we compared CBA plus intracardiac echocardiography (ICE) to our former standard approach without ICE. A substantial reduction of radiation exposure without compromising safety or outcome was observed. We now investigate if at all and possibly to which amount radiation reduction can be achieved with growing experience.

METHODS

We retrospectively analysed procedure time, dose area product (DAP), fluoroscopy time (FT) and contrast media (CM) use for all patients receiving CBA between 2013 and 2017 for AF.

RESULTS

In 1131 procedures, procedure time decreased significantly between 2013 and 2017 (2013 111 ± 26 min, 2017 99 ± 25 min, p = 0.005). DAP halved between 2013 and 2014 without further significant decline (2013 1428 ± 1276 cGycm², 2014 725 ± 551 cGycm², p < 0.001). FT demonstrated a constant decrease from 2013 to 2017 (2013 11.7 ± 5.5 min, 2017 5.1 ± 3.5 min, p < 0.001). CM use did not show a significant reduction comparing 2013 to 2017 (2013 62 ± 19 ml, 2017 59 ± 18 ml, 2013/2017 p = 0.584).

CONCLUSION

Given the imminent negative effects of radiation, every effort should be undertaken for its reduction. Feasible protocols can be kept simple by technical changes as reducing frame rates and basic radiation reduction strategies such as collimation, but ICE might add additional benefit. With growing experience and awareness of radioprotection, DAP and FT as low as or lower than in radiofrequency ablations seem possible.

The safety and efficacy of second-generation cryoballoon ablation plus catheter ablation for persistent atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Growing evidence suggests that second-generation cryoballoon ablation (2G-CB) is effective in patients with persistent atrial fibrillation (PerAF). The cornerstone of atrial fibrillation (AF) ablation is pulmonary vein isolation (PVI). The purpose of this study was to summarize the available data on the safety and mid-term (≥ 12 months) effectiveness of a 'PVI-only' strategy vs. a 'PVI-plus' strategy using 2G-CB in patients with PerAF.

METHODS

We searched the PubMed, EMBASE and Cochrane library databases for studies on 2G-CB for PerAF. Group analysis was based on the ablation approach: 'PVI-only' versus 'PVI-plus', the latter of which involved PVI plus other substrate modifications. Studies showing clinical success rates at a follow-up (FU) of ≥ 12 months were included. Complication rates were also assessed. Data were analyzed by applying a fixed effects model.

RESULTS

A total of 879 patients from 5 studies were analyzed. After a mid-term FU of 27 months, the overall success rate of 2G-CB for PerAF was 66.1%. In the 'PVI-plus' group, the success rate was 73.8%. In the 'PVI-only' group, the success rate was 53.6%. No heterogeneity was noted among studies (I2 = 0.0%, P = 0.82). Complications occurred in 5.2% of patients (P = 0.93), and the rate of phrenic nerve (PN) injury was 2.8% (P = 0.14). Vascular assess complications were the most frequent at 1.6% (P = 0.33). No death or myocardial infarction was reported.

CONCLUSION

'PVI-plus' involving 2G-CB seems to be safe and effective for treating PerAF.

Compass Mapping, Double Potentials, Activation Patterns Can Identify and Track Rotational Activity Sites in the Left Atrium of Humans with Persistent Atrial Fibrillation

BACKGROUND

Rotational circuits that occur between bipolar electrodes exhibit double potentials (DPs). It had been previously surmised that rotors could not be electrically tracked directly.

PURPOSE

Our purpose was twofold; first, to show that the use of compass mapping, one can regionally identify rotational activity; and second, to show that by combining simultaneous compass map recordings, standard narrow-adjacent bipolar, and unipolar recordings, that specific signature recording patterns emerge that allow one to identify the accurate time, location, and path of a rotational mechanism.

METHODS

This was an observational study in 20 patients with persistent atrial fibrillation in which the electrode configuration of a circular mapping catheter was changed to wide cross-circle electrode pairing (compass mapping). DPs were recorded and analyzed from 12 left atrial (LA) sites and identified electrical wavefront patterns and direction. A substudy analyzed transitions patterns with simultaneous narrow-adjacent bipolar and unipolar recordings.

RESULTS

Four wavefront patterns were identified: DPs, peripheral waves (PWs), distal peripheral waves and fibrillatory activity. DP wavefront patterns exhibited significantly shorter cycle lengths than PWs in 8 of 12 LA sites. Patients had 2.9± 2.1 regions that exhibited DPs. DPs of varying duration were found, few (25%) were of stable duration and location. Detailed electrical examination at the transition between a PW to a DP identified a highly consistent pattern of simultaneous reversal of activation sequence, a special form of Doppler effect for spiral waves as a rotor passes between 2 electrodes, and a ½ cycle drop-off of activation signals along the line of electrodes.

CONCLUSION

DP recordings in compass mode can provide a regional assessment for the existence of rotational activity. Simultaneous DP recordings in compass mode, narrow-adjacent bipolar, and unipolar recording provide an accurate assessment of the time, location, and path that a rotational mechanism breaches a perimeter of electrodes. Accurate time, location and path of perimeter breaches can be used to electrically track rotational mechanisms during atrial fibrillation.

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

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

Safety and efficacy of persistent atrial fibrillation ablation using the second-generation cryoballoon

BACKGROUND

The second-generation cryoballoon (CB) is increasingly used for treatment of persistent atrial fibrillation (AF). Data regarding the clinical outcome and mechanism of arrhythmia recurrence following persistent AF ablation using CB is sparse. In this study, we aimed to assess the efficacy of CB and mechanisms of atrial tachyarrhythmia (ATA) recurrence in patients with persistent AF.

METHODS AND RESULTS

A total of 133 patients (66 ± 10 years, 60% male) with symptomatic persistent AF, who were scheduled for PVI using the second-generation CB were enrolled. Follow-up included 24 h Holter recording at 3, 6 and 12 months. Any documented episode of ATA lasting more than 30 s was considered as a recurrent arrhythmic event. All targeted veins were isolated (100%). Phrenic nerve palsy with recovery during follow-up occurred in six patients (4.5%), no patient experienced tamponade or a cerebrovascular event. During 12.6 ± 5.4 months of follow-up, 89/133 (67%) patients were free of ATA recurrences. Multivariable analysis revealed recurrence in the blanking period (HR 11.46, 0.95 CI 3.92-33.49, p < 0.001), presence of cardiomyopathy (HR 2.75, 0.95 CI 1.09-6.96, p = 0.032) and PV abnormality (HR 3.56, 0.95 CI 1.21-10.43, p = 0.021) as predictors for late recurrence.

CONCLUSION

In patients with persistent AF, second-generation cryoballoon use is associated with an excellent safety profile and favorable outcomes. Arrhythmia recurrence during the blanking period, presence of cardiomyopathy and PV abnormality were independent predictors of long-term AF recurrence.