Cryoballoon Versus Open Irrigated Radiofrequency Ablation in Patients With Paroxysmal Atrial Fibrillation: The Prospective, Randomized, Controlled, Noninferiority FreezeAF Study

Comparison of Cryoballoon and Ablation Index-Guided Radiofrequency Ablation in Paroxysmal Atrial Fibrillation

Background: Atrial fibrillation is the most common sustained arrhythmia worldwide. Pulmonary vein isolation (PVI) is the most effective catheter ablation technique for treating paroxysmal atrial fibrillation (pAF). Common ablation methods include point-by-point radiofrequency (RF) ablation and single-shot techniques such as cryoballoon ablation (CB). This single-center, prospective study aimed to compare the efficacy of ablation index-guided RF ablation (AI-RF) and CB in patients with symptomatic, antiarrhythmic-resistant pAF. Methods: A total of 154 patients undergoing initial PVI were divided into two groups (CB: 51, AI-RF: 103), based on the operators' decision. Procedural data (total procedure time, fluoroscopy time, radiation dose, complication rate) and recurrence rates were analyzed over a 12-month follow-up period. Results: The CB group had a significantly shorter total procedure time compared to the AI-RF group (64 [57; 74.8] minutes vs. 92 [76; 119] minutes; p < 0.001). However, the CB group experienced higher fluoroscopy times (559 [395; 868] seconds vs. 167 [126; 224] seconds; p < 0.001) and a greater fluoroscopy dose (21.8 [11.7; 40.1] mGy vs. 7.65 [5.21; 14.5] mGy; p < 0.001). Recurrence rates were similar during both the blanking period (11.7% vs. 10.7%; p = 0.84) and the 12-month follow-up period (22.7% vs. 13.4%; p = 0.22). No major complications were reported during this study. Conclusions: In this single-center study, there were no significant differences in long-term recurrence or complication rates between the CB and AI-RF groups for patients with antiarrhythmic-refractory, symptomatic pAF. While the CB group benefited from a significantly shorter procedure time, it required a higher fluoroscopy dose and a longer fluoroscopy time.

Catheter Ablation of Atrial Fibrillation: Technique and Future Perspectives

Atrial fibrillation is the most common sustained cardiac arrhythmia with a significant impact on quality of life in terms of symptoms and reduction of functional status. Also, it is associated with an increased risk of mortality, stroke, and peripheral embolism. Catheter ablation for atrial fibrillation has become a well-established treatment, improving arrhythmia outcomes without increasing the risk of serious adverse events compared to antiarrhythmic drug therapy. The field has undergone significant advancements in recent years, yet pulmonary vein isolation continues to be the cornerstone of any atrial fibrillation ablation procedure. The purpose of this review is to provide an overview of the current techniques, emerging technologies, and future directions.

Comparison of P-wave parameter changes after radiofrequency ablation and cryoballoon ablation for paroxysmal atrial fibrillation: An observational cohort study

BACKGROUND

Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) can be performed using one-shot cryoballoon ablation (cryo) or point-by-point radiofrequency ablation (RF). This study compares the changes in P-wave parameters between both ablation methods.

METHODS

This single-centre retrospective study included contact force RF and second-generation cryo for PAF between 2018 and 2019. Procedure success was defined by freedom of ECG-documented AF at 12 months. Digital 12‑leads ECGs with 1-50 hertz bandpass filters were monitored directly during the procedure. Corrected P-wave duration (PWDc), P-wave voltage (PWV), P-wave dispersion (PWDisp), and P-wave terminal force in V1 (PTFV1) were measured and compared between RF and cryo. Additional ablations outside pulmonary veins were excluded.

RESULTS

The final analysis included 226 patients, and the freedom of AF rate was similar at the 12-month follow-up between RF and cryo (76 % vs 74 %, P = 0.12). PWDc and PWV increased and decreased, respectively in both arms. PTFV1 decreased in RF (-3.3 mm.s to -4.6 mm.s, P < 0.001) and cryo (-3.4 mm.s to -5.3 mm.s,P = 0.002). There were similar changes after RF and cryo in PWDc (F11, 1032 = 0.80, P = 0.85), PWV (F11, 1032 = 0.19,P = 0.06), and PWDisp (F11, 1032 = 0.16,P = 0.34) and PTFV1 (P = 0.39). Increased PWDc was correlated with failure of RF (hazard ratio [2.3], 95 % confidence interval [CI]: 1.4-5.9, p = 0.01) and cryo (HR: 2.1, 95 % CI (1.3-4.6), p = 0.02). Results were similar when patients on antiarrhythmic drugs were excluded.

CONCLUSION

RF and cryo caused similar freedom of AF rate at 12 months in PAF and similar P-wave parameter changes.

In-hospital safety of cryoballoon and radiofrequency ablation in patients with atrial fibrillation-German nationwide analysis of more than 300,000 procedures

BACKGROUND

Pulmonary vein isolation can be performed by radiofrequency (RF) or cryoballoon (CB) ablation. Guidelines do not favor one technique, and knowledge about complication rates is limited.

OBJECTIVE

We aimed to report the procedural safety of RF and CB ablation using data from a German nationwide real-world registry.

METHODS

By use of health records, all left atrial catheter ablation procedures with RF or CB ablation in Germany from 2013 to 2021 were analyzed. After adjustment for confounders, safety performance end points were compared.

RESULTS

From 2013 to 2021, RF ablation was performed in 184,616 patients and CB ablation in 118,984 patients with increasing trends in patient numbers and performing centers for both procedures. Patients with RF ablation had slightly more comorbidities. In-hospital mortality (RF, 0.08%; CB, 0.06%) and other investigated complications were rare. After adjustment for patient baseline characteristics, the risk of in-hospital mortality, serious bleeding, stroke, intracerebral bleeding, and acute kidney injury did not differ. The risk of pericardiocentesis (relative risk, 0.50; 95% confidence interval, 0.46-0.55; P < .001), vascular complication (0.36; 0.33-0.39; P < .001), and ventilation >48 hours (0.81; 0.66-0.99; P = .042) was significantly lower for CB ablation. Pericardiocentesis risk negatively correlated with annual procedure numbers per center with a faster learning curve for CB ablation (both P < .01).

CONCLUSION

RF and CB ablation had low overall procedural complication rates, with CB ablation showing a 50% reduced risk of pericardiocentesis. Centers with higher volume provided a better in-hospital safety with a faster learning curve for CB ablation.

Global Research Progress on Radiofrequency Ablation in Cardiology

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

Representation of Women in Atrial Fibrillation Ablation Randomized Controlled Trials: Systematic Review

BACKGROUND

Sex inequality in randomized controlled trials (RCTs) related to cardiovascular disease has been observed. This study examined the proportion of women enrolled in atrial fibrillation (AF) ablation RCTs and the potential risks of underrepresentation of women.

METHODS AND RESULTS

We systematically searched PubMed and Embase for AF ablation RCTs published from 2015 to 2022. Participant characteristics were compared among trials with higher and lower proportions of women. Of 147 AF ablation RCTs (30,055 participants), only 10 trials had enrolled women ≥50% of the total participants. Additionally, 42 trials (28.57%) excluded pregnant/breastfeeding women; 6 (4.1%) excluded reproductive-age women without reliable birth control. The proportion of women in AF RCTs ranged from 9% to 71% (median 31.5%), whereas the median proportion of men was 67.7%. The rate of women included in the trials was stable from 2015 to 2022 (P=0.49). Study characteristics, including funding source, showed no correlation with the rate of inclusion of women. RCTs with a higher proportion of female participants enrolled older patients with AF, had a higher prevalence of hypertension but less persistent AF, and smaller left atrium size (P<0.05 for all). Biological sex was evaluated as a risk factor or in a subgroup analysis in 28 RCTs; 10.7% of these trials observed the implication of sex on their results.

CONCLUSION

Women were underrepresented in contemporary AF ablation RCTs. Additionally, women enrolled in AF RCTs were likely to have more comorbidities but less advanced AF, limiting the applicability of the results to women with AF.

The Efficacy and Safety of Cryoballoon Versus Radiofrequency Ablation for the Treatment of Atrial Fibrillation: A Meta-Analysis of 15 International Randomized Trials

The purpose of this study was to evaluate the efficacy and safety of cryoballoon versus radiofrequency ablation for the treatment of atrial fibrillation (AF) by systematically reviewing randomized controlled trials (RCTs). Databases of Pubmed, Web of science, Embase, and Cochrane Library were searched for published studies up to June 31, 2022. Only RCTs comparing the efficacy and safety of cryoballoon vs radiofrequency ablation for the treatment of AF were enrolled in meta-analysis. Fifteen RCTs characterizing 2709 patients were finally included. Meta-analysis found that cryoballoon ablation was associated with a similar proportion of patients free from AF [risk ratio (RR): 1.02; 95% confidence interval (CI): 0.93 to 1.12, P = 0.65]. Acute pulmonary vein isolation rate [RR: 1.0; 95% CI: 0.98 to 1.01, P = 0.64] and fluoroscopy time (weighted mean difference: -0.03; 95% CI: -4.35 to 4.28; P = 0.99) were not statistically significant difference. The procedure time was shorter in the cryoballoon ablation (CBA) group (weighted mean difference : -18.76; 95% CI: -27.27 to -10.25; P < 0.0001). Transient phrenic nerve palsy was uniquely observed in the CBA group (RR = 6.66; 95% CI: 2.82 to 15.7, P < 0.0001) and resolved in all during the follow-up period, total complication was similar in both groups (RR = 1.24; 95% CI: 0.86 to 1.79, P = 0.24). Although the procedure time was shorter in CBA group, the efficacy and safety were similar in each group. Compared with radiofrequency ablation for the treatment of AF, patients receiving cryoballoon ablation have similar outcomes. CBA is associated with a shorter duration of procedure.

Safety of different therapies for atrial fibrillation: a network meta-analysis

OBJECTIVE

Most published studies have aimed to compare the effectiveness of different treatment strategies for atrial fibrillation (AF), while few articles have comprehensively compared the safety of therapeutic measures.The aim of the article was to assess the safety of different therapeutic measures (different ablation techniques, antiarrhythmic drugs and surgery) in patients with AF.

METHOD

A comprehensive and systematic search was undertaken across various databases, namely PubMed, Embase, Cochrane Library, and Web of Science, with the aim of identifying pertinent randomized controlled trials (RCTs) that delve into the safety aspects of diverse atrial fibrillation treatment strategies. The search was conducted up until December 1st, 2023. R4.2.3 software gemtc package was used for data analysis, Review Manager 5.3 was used for quality assessment of included studies, and stata15.0 was used for publication bias.Safety is defined as the adverse outcomes that occur in different treatment strategies for atrial fibrillation, with specific adverse events as described below.

RESULT

22 RCTs (involving 5073 subjects) with interventions including cryoballoon ablation (CA), radiofrequency ablation (RF), laser balloon ablation (LB), pulmonary vein ablation catheter (PVAC), antiarrhythmic drugs (AADS), and surgery (SA) were included in this study. In this article, medication and surgery were combined into the same intervention (non-traditional treatment measure, UT). UT was not associated with pericardial effusion (OR:4.27e-10, 95%CI:4.91e-30-0.0663), infections (OR:0.248, 95%CI:0.0584-0.89), arrhythmias (OR:0.609,95%CI:0.393-0.936), pseudoaneurysms (OR:5.57e-10, 95%CI:1.16e-31-0.934) and pulmonary vein stenosis (OR:1.16e-09, 95%CI:6.56e-24-0.194). Complications of the procedure were mainly mechanical injuries. Among the various ablation strategies, radiofrequency ablation had a lower incidence of phrenic nerve palsy and pain (OR:4.01e-06, 95%CI:1.18e-17-0.710) than cryoballoon ablation, which was superior to radiofrequency ablation in terms of infection rates. Finally, there were no significant differences between the various ablation techniques in terms of other complication rates.

CONCLUSION

Because the interventions in the UT group were predominantly AADS and antiarrhythmic drug therapy didn't have some of the common aggressive complications of ablation strategies, the UT group had a low rate of complications such as pericardial effusion, postprocedural arrhythmia, pseudoaneurysm, and pulmonary vein stenosis compared with various catheter ablation strategies. Additionally, we also discovered between the various ablation technology groups, there was no significant difference in the incidence of major adverse events.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registry number:CRD42024566530.

Efficacy and safety of high-power short-duration ablation for atrial fibrillation: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

High-power short-duration (HPSD) ablation has emerged as an alternative to conventional standard-power long-duration (SPLD) ablation. We aim to assess the efficacy and safety of HPSD versus SPLD for atrial fibrillation (AF) ablation.

METHODS

A systematic review and meta-analysis of randomized controlled trials (RCTs) retrieved from PubMed, WOS, SCOPUS, EMBASE, and CENTRAL were performed through August 2023. We used RevMan V. 5.4 to pool dichotomous data using risk ratio (RR) and continuous data using mean difference (MD) with a 95% confidence interval (CI).

PROSPERO ID

CRD42023471797.

RESULTS

We included six RCTs with a total of 694 patients. HPSD was significantly associated with a decreased total procedure time (MD: -22.88 with 95% CI [-36.13, -9.63], P = 0.0007), pulmonary vein isolation (PVI) time (MD: -19.73 with 95% CI [-23.93, -15.53], P < 0.00001), radiofrequency time (MD: -10.53 with 95% CI [-12.87, -8.19], P < 0.00001). However, there was no significant difference between HPSD and SPLD ablation with respect to the fluoroscopy time (MD: -0.69 with 95% CI [-2.00, 0.62], P = 0.30), the incidence of esophageal lesions (RR: 1.15 with 95% CI [0.43, 3.07], P = 0.77), and the incidence of first pass isolation (RR: 0.98 with 95% CI [0.88, 1.08], P = 0.65).

CONCLUSION

HPSD ablation was significantly associated with decreased total procedure time, PVI time, and radiofrequency time compared with SPLD ablation. On the contrary, SPLD ablation was significantly associated with low maximum temperature.

Atrial Fibrillation in Hypertrophic Cardiomyopathy

Atrial fibrillation (AF) is common among patients with hypertrophic cardiomyopathy (HCM) with a prevalence greater than 25%. AF in HCM is associated with a high risk of stroke and can be a marker of more advanced cardiomyopathy. Although, it frequently results in cardiac hemodynamic changes which are poorly tolerated, it can be subclinical. Thus, prompt diagnosis and adequate management of AF are essential to minimizing AF-related adverse outcomes in HCM. All HCM patients should be screened for AF regularly, and those with high-risk features should be screened more frequently preferably with extended ambulatory monitoring. Once AF is detected, oral anticoagulation should be initiated. Both general and HCM-specific modifiable risk factors should be addressed and assessment for cardiomyopathy progression should be performed. Although no randomized controlled studies have compared rate versus rhythm control in HCM, early rhythm control could be considered to prevent further LA remodeling.

Method, safety, and outcomes of persistent AF ablation without a circular mapping catheter: 3 years experience of a Belgian Tertiary Centre

BACKGROUND

We aimed to share our methods and experience of persistent AF ablation without a circular mapping catheter (CMC), thereby avoiding femoral venous and transseptal punctures, decreasing the cost of the procedure, and possibly reducing the duration of the procedure and fluoroscopy time.

METHODS

We report our experience with 261 persistent AF ablations performed without a CMC over the past 3 years.

RESULTS

The procedures were performed with no apparent loss of efficacy or safety. Freedom from recurrence was defined as a 1-year absence of AF/atrial flutter (AFL) episodes >30 s, beyond the 3-month blanking period. At 1 year, 72% of the patients were free from arrythmias.

CONCLUSIONS

Persistent AF ablation is feasible without a CMC, reducing the need for venous and transseptal punctures and the cost of the procedure. We suggest that prospective studies should aim to characterise the reduction in procedure and fluoroscopy times as a result of this technique.

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

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

Catheter Ablation for Atrial Fibrillation-Influence of Modifiable Risk Factors and Ablation Modality on Procedural Efficacy and Safety

BACKGROUND

Modifiable lifestyle risk factors, in particular obesity and related conditions, are important drivers of atrial fibrillation (AF), impacting the severity of symptoms and influence the efficacy and safety of treatment.

OBJECTIVE

The study aimed to assess the impact of modifiable lifestyle factors on the effectiveness and safety of AF ablation, and examine the procedural characteristics, efficacy, safety and cost outcomes of cryoballoon vs radiofrequency ablation, in a real-world clinical setting.

METHOD

Patients undergoing catheter ablation for AF (June 2017 to December 2020) were included in this retrospective analysis. Efficacy and safety outcomes were obtained from electronic medical records and state-wide databases. The primary outcome was successful isolation of the pulmonary veins and freedom from AF without repeat ablation or ongoing antiarrhythmic therapy at 12 months.

RESULTS

The study included 141 patients (mean age 60±11 years, 57% male). The average body mass index (BMI) was 29.2±5.6 kg/m2. Ablation by cryoballoon was undertaken in 59% (radiofrequency 41%). Acutely successful pulmonary vein isolation was achieved in 92%, however, only 52% (n=74) met the primary outcome (successful isolation of the pulmonary veins and freedom from AF without repeat ablation or ongoing antiarrhythmic therapy) at 12 months. Successful management of AF was more likely in patients with lower BMI (p=0.006; particularly with BMI <27 kg/m2; p=0.004) and weight (p=0.003), and in those without obstructive sleep apnoea (p=0.032). The only independent predictor of the primary outcome was BMI (β=0.25, p=0.004). Over 75% of complications occurred in those with BMI ≥27 kg/m2.

CONCLUSIONS

Catheter ablation for AF is more likely to be unsuccessful in patients with uncontrolled risk factors, particularly obesity. Risk factor optimisation may improve procedural success and reduce the risk of procedural complications.

2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF.

Pulsed Field Energy in Atrial Fibrillation Ablation: From Physical Principles to Clinical Applications

Atrial fibrillation, representing the most prevalent sustained cardiac arrhythmia, significantly impacts stroke risk and cardiovascular mortality. Historically managed with antiarrhythmic drugs with limited efficacy, and more recently, catheter ablation, the interventional approach field is still evolving with technological advances. This review highlights pulsed field ablation (PFA), a revolutionary technique gaining prominence in interventional electrophysiology because of its efficacy and safety. PFA employs non-thermal electric fields to create irreversible electroporation, disrupting cell membranes selectively within myocardial tissue, thus preventing the non-selective damage associated with traditional thermal ablation methods like radiofrequency or cryoablation. Clinical studies have consistently shown PFA's ability to achieve pulmonary vein isolation-a cornerstone of AF treatment-rapidly and with minimal complications. Notably, PFA reduces procedure times and has shown a lower incidence of esophageal and phrenic nerve damage, two common concerns with thermal techniques. Emerging from oncological applications, the principles of electroporation provide a unique tissue-selective ablation method that minimizes collateral damage. This review synthesizes findings from foundational animal studies through to recent clinical trials, such as the MANIFEST-PF and ADVENT trials, demonstrating PFA's effectiveness and safety. Future perspectives point towards expanding indications and refinement of techniques that promise to improve AF management outcomes further. PFA represents a paradigm shift in AF ablation, offering a safer, faster, and equally effective alternative to conventional methods. This synthesis of its development and clinical application outlines its potential to become the new standard in AF treatment protocols.

Comparison of Second-Generation Cryoballoon Ablation and Quantitative Radiofrequency Ablation Guided by Ablation Index for Atrial Fibrillation

We compared the efficacy and complication rates of quantitative radiofrequency ablation guided by ablation index (RFCA-AI) with those of second-generation cryoballoon ablation (CBA-2). Consecutive patients (n = 230) with symptomatic atrial fibrillation (AF) undergoing a first ablation CBA-2 (92 patients) or RFCA-AI (138 patients) procedure were enrolled in this study. The late recurrence rate in the CBA-2 group was higher than that in the RFCA-AI group (P = .012). Subgroup analysis showed the same result in patients with paroxysmal AF (PAF) (P = .039), but no difference was found in patients with persistent AF (P = .21). The average operation duration in the CBA-2 group (85 [75-99.5] minutes) was shorter than that in the RFCA-AI group (100 [84.5-120] minutes) (P < .0001), but the average exposure time (17.36(13.87-22.49) vs 5.49(4.00-8.24) minutes) in the CBA-2 group and X-ray dose (223.25(149.15-336.95) vs 109.15(80.75-168.7) mGym) were significantly longer than those in RFCA-AI group (P < .0001). Multivariate logistic regression analysis showed that left atrial diameter (LAD), early recurrence, and methods of ablation (cryoballoon ablation) were independent risk factors for late recurrence after AF ablation. Early recurrence of AF and LAD were independent risk factors for predicting late recurrence after AF ablation.

Pentaspline Pulsed Field Ablation Catheter Versus Cryoballoon for Atrial Fibrillation Ablation: Results From a Prospective Comparative Study

BACKGROUND

Cryoballoon ablation is currently the gold standard technique for single-shot pulmonary vein isolation (PVI). Pulsed field ablation (PFA) has recently emerged as an interesting nonthermal alternative energy for PVI. The purpose of our study was to evaluate the safety and long-term efficacy of PVI using the pentaspline PFA catheter in comparison to cryoballoon ablation.

METHODS AND RESULTS

Between January 2021 and December 2022, we included all consecutive patients of our center in whom a first PVI-only procedure was performed using PFA or cryoballoon. The choice of the energy was based on patients' preference between general anesthesia (PFA) and local anesthesia (cryoballoon). The primary end point was freedom from documented atrial arrhythmia recurrence after a 3-month blanking period. A total of 301 patients (paroxysmal atrial fibrillation in 220 patients) underwent a first PVI procedure performed using PFA (n=151) or cryoballoon (n=150). Complete short-term PVI was obtained in 144 of 150 patients (96%) in the cryoballoon group and in all patients of the PFA group (P=0.01). Procedure duration was significantly longer in the cryoballoon group. Transient and persistent phrenic nerve injuries were observed in the cryoballoon group only (13/150 and 2/150, respectively). One-year freedom from atrial arrhythmia was significantly higher in the PFA group compared with the cryoballoon group (87.9% versus 77.7%; adjusted hazard ratio, 0.53 [95% CI, 0.30-0.96]; P=0.037).

CONCLUSIONS

This prospective, comparative, real-life study suggested that PFA could overcome safety limitations of cryoballoon with optimal effectiveness. Randomized controlled studies are required to further investigate the potential superiority of PFA over cryoballoon.

Prognostic implication of early recurrence after cryoballoon ablation in patients with atrial fibrillation

BACKGROUND

It remains uncertain whether the implication of early recurrence and blanking period can be applied to patients with atrial fibrillation (AF) treated with cryoballoon ablation (CBA). We aimed to explore the prognostic value of early recurrence in patients with AF treated with CBA.

METHODS

We studied consecutive AF patients who were treated with CBA between April 2019 and September 2020 in two tertiary medical institutes and followed for up to 12 months. The endpoint was the late recurrence of atrial arrhythmia, including AF, atrial flutter, and atrial tachycardia, following a 90-day blanking period. Atrial arrhythmia during the blanking period was defined as early recurrence and was not considered as an endpoint.

RESULTS

This study included 406 patients with AF who underwent CBA. During the follow-up, 147 (36.2%) cases of late recurrence were observed. Of the 104 patients with early recurrence, 85 experienced late recurrence during follow-up. Early recurrence was associated with an increased risk of late recurrence in the univariate and multivariate analyses (P < 0.001). When we classified the patients into paroxysmal AF and persistent AF groups, early recurrence was still significantly associated with a higher risk of late recurrence (P = 0.005 and P < 0.001, respectively).

CONCLUSION

Early recurrence after CBA was an independent risk factor for late recurrence in all patients as well as in those with paroxysmal AF and persistent AF. Therefore, further prospective studies could be considered to verify the risks and benefits of early rhythm control in patients with early recurrence.

Rationale and design of the VAST-AF trial: A randomized controlled, blinded, clinical trial to evaluate transcutaneous vagal nerve stimulation for the prevention of persistent atrial fibrillation recurrence

BACKGROUND

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and is linked to significant symptoms and an elevated risk of heart failure, thromboembolism and disabling stroke. Not only do patients suffer from AF and the concomitant complications, but it is a great economic burden for healthcare systems all over the world. Despite remarkable progress in the field of AF, the basic mechanisms of AF development remain unresolved. Data suggests that the (cardiac) autonomous nervous system (ANS) plays a significant role in AF. Recent studies have shown that stimulating the ANS could have a beneficial effect on paroxysmal and postoperative AF. Consequently, this therapy could provide another viable target for treating persistent AF, as well.

METHODS

The VAST-AF trial is a prospective, double-blinded, randomized, and sham-controlled clinical trial. One hundred and twenty patients diagnosed with persistent AF and cardioversion in sinus rhythm (SR) will be randomly assigned to either transcutaneous vagal nerve stimulation (tVNS) or sham treatment in a 1:1 ratio. The primary objective of this study is to examine whether a daily tVNS reduces the recurrence rate of AF. Secondary endpoints include quality of life, time to first AF recurrence and ECG parameters of the ANS. Follow-up is scheduled at 30 days, 3 and 6 months. After 3 months, stimulation is withdrawn, and patients evaluated regarding a still detectable effect of tVNS.

CONCLUSION

The VAST-AF trial represents the first randomized and sham-controlled study to investigate the potential benefits of transcutaneous vagal nerve stimulation on the recurrence of atrial fibrillation. Patients with persistent atrial fibrillation and successful electrical cardioversion will be assessed. A decrease in the rate of recurrence and consecutive hospitalizations could decidedly enhance the quality of life of patients and decrease healthcare expenses. Nevertheless, it does not compete with treatments such as catheter ablation, but rather serves as an additional tool in the armamentarium of the electrophysiologist.

Characteristics of two different cryoballoon systems for treatment of paroxysmal atrial fibrillation: study protocol for a multicenter randomized controlled trial (CONTRAST-CRYO Trial)

BACKGROUND

Single-shot pulmonary vein isolation (PVI) utilizing cryothermal energy is an effective and safe treatment for atrial fibrillation (AF) patients. A novel cryoballoon system, POLARx™, has been recently introduced. The aim of this study was to compare the efficacy, safety, and biophysical parameters of PVI between the novel cryoballoon system, POLARx™, and the standard cryoballoon system, Arctic Front Advance Pro™ (AFA-Pro), in patients with paroxysmal AF.

METHODS

The CONTRAST-CRYO trial is a prospective, multicenter, open-label, randomized controlled study performed at seven large cardiac centers. This study was approved by the central ethics committee or the local ethics committee of each participating hospital and has been registered at UMIN Clinical Trials Registry (UMIN000049948). The trial will assign 200 patients with paroxysmal AF undergoing PVI to POLARx™ and AFA-Pro in a 1:1 randomization. The primary endpoint is the one-shot acute success rate of the right inferior pulmonary vein. Second endpoints include freedom from documented atrial fibrillation, atrial flutter, or atrial tachycardia without antiarrhythmic drugs at 12 months after the procedure, freedom from re-do procedures, the incidence of procedure-related adverse events, freezing duration, and the biophysical parameters during applications for each PV, total procedure and fluoroscopy time, and PVI durability during re-do procedures.

CONCLUSION

The CONTRAST-CRYO trial is a prospective, multicenter, randomized study designed to elucidate the difference in the efficacy, safety, and biophysical parameters between POLARx™ and AFA-Pro in paroxysmal AF patients undergoing PVI. The findings from this trial may provide a valuable indication for selecting the optimal cryoballoon system.

CLINICAL TRIAL REGISTRATION

 UMIN000049948.

Current Balloon Devices for Ablation of Atrial Fibrillation

Balloon-based catheter ablation is a valuable option for the treatment of atrial fibrillation (AF) because contiguous lesions can be created to achieve pulmonary vein isolation (PVI), and the method is less dependent than traditional ablation methods on the operator's skill and experience. Cryoballoon ablation is used universally worldwide, with its efficacy and safety being comparable to the efficacy and safety of standard radiofrequency ablation, and the procedure can be completed in a relatively short time. Hot balloon ablation was developed in Japan. The balloon maintains its compliance even during the energy delivery, and a large areal ablation lesion is created. Furthermore, the hot balloon system is the only system for which oesophageal cooling is a standard feature. Laser balloon ablation, which is performed under direct endoscopic vision, has proven to be effective and safe for achieving a PVI. The laser balloon system provides an improved field of view and automated circumferential ablation for a rapid and effective PVI. The authors have reviewed the currently available balloon systems as used for AF ablation, i.e., PVI, and have provided detailed insight and perspectives on the currently available cryoballoon and hot balloon technologies, plus laser balloon technology.

Efficacy and safety of pulmonary vein isolation with pulsed field ablation vs. novel cryoballoon ablation system for atrial fibrillation

AIMS

Pulsed-field ablation (PFA) has emerged as a novel treatment technology for patients with atrial fibrillation (AF). Cryoballoon (CB) is the most frequently used single shot technology. A direct comparison to a novel CB system is lacking. We aimed to compare pulmonary vein isolation (PVI) using PFA vs. a novel CB system regarding efficiency, safety, myocardial injury, and outcomes.

METHODS AND RESULTS

One hundred and eighty-one consecutive patients underwent PVI and were included (age 64 ± 9.7 years, ejection fraction 0.58 ± 0.09, left atrial size 40 ± 6.4 mm, paroxysmal AF 64%). 106 patients (59%) underwent PFA (FARAPULSE, Boston Scientific) and 75 patients (41%) underwent CB ablation (PolarX, Boston Scientific). The median procedure time, left atrial dwell time and fluoroscopic time were similar between the PFA and the CB group with 55 [interquartile range (IQR) 43-64] min vs. 58 (IQR 48-69) min (P < 0.087), 38 (30-49) min vs. 37 (31-48) min, (P = 0.871), and 11 (IQR 9.3-14) min vs. 11 (IQR 8.7-16) min, (P < 0.81), respectively. Three procedural complications were observed in the PFA group (two tamponades, one temporary ST elevation) and three complications in the CB group (3× reversible phrenic nerve palsies). During the median follow-up of 404 days (IQR 208-560), AF recurrence was similar in the PFA group and the CB group with 24 vs. 30%, P = 0.406.

CONCLUSION

Procedural characteristics were very similar between PFA and CB in regard to procedure duration fluoroscopy time and complications. Atrial fibrillation free survival did not differ between the PFA and CB groups.

Robotic magnetic navigation-guided catheter ablation establishes highly effective pulmonary vein isolation in patients with paroxysmal atrial fibrillation when compared to conventional ablation techniques

INTRODUCTION

Pulmonary vein isolation (PVI) is a pivotal part of ablative therapy for atrial fibrillation (AF). Currently, there are multiple techniques available to realize PVI, including: manual-guided cryoballoon (MAN-CB), manual-guided radiofrequency (MAN-RF), and robotic magnetic navigation-guided radiofrequency ablation (RMN-RF). There is a lack of large prospective trials comparing contemporary RMN-RF with the more conventional ablation techniques. This study prospectively compared three catheter ablation techniques as treatment of paroxysmal AF.

METHODS

This multicenter, prospective study included patients with paroxysmal AF who underwent their first ablation procedure. Procedural parameters (including procedural efficiency), complication rates, and freedom of AF during 12-month follow-up, were compared between three study groups which were defined by the utilized ablation technique.

RESULTS

A total of 221 patients were included in this study. Total procedure time was significantly shorter in MAN-CB (78 ± 21 min) compared to MAN-RF (115 ± 41 min; p < .001) and compared to RMN-RF (129 ± 32 min; p < .001), whereas it was comparable between the two radiofrequency (RF) groups (p = .062). A 3% complication rate was observed, which was comparable between all groups. At 12-month follow-up, AF recurrence was observed in 40 patients (19%) and was significantly lower in the robotic group (MAN-CB 19 [24%], MAN-RF 16 [23%], RMN-RF 5 [8%] AF recurrences, p = .045) (multivariate hazard ratio of RMN-RF on AF recurrence 0.32, 95% confidence interval: 0.12-0.87, p = .026).

CONCLUSION

RMN-guided PVI results in high freedom of AF in patients with paroxysmal AF, when compared to cryoablation and manual RF ablation. Cryoablation remains the most time-efficient ablation technique, whereas RMN nowadays has comparable efficiency with manual RF ablation.

Atrial Fibrillation Ablation in Patients With Chronic Kidney Disease: A Review of Literature

Atrial fibrillation (AF) is a common arrhythmia among patients with chronic kidney disease (CKD), which leads to increased cardiovascular complications. Catheter ablation (CA) has emerged as an effective and safe treatment for AF in CKD patients. CA offers tailored treatment strategies and presents a safer alternative with fewer adverse outcomes than anti-arrhythmic agents. Although CKD patients undergoing ablation have similar complication rates to non-CKD patients, they face a higher risk of hospitalization due to heart failure. Furthermore, CA shows promise in improving kidney function, particularly in individuals who maintain sinus rhythm. Future research should address limitations by including advanced CKD patients, conducting longer-term follow-ups, and developing individualized treatment approaches.

Evaluation of Pulmonary Vein Fibrosis Following Cryoballoon Ablation of Atrial Fibrillation: A Semi-Automatic MRI Analysis

Current guidelines recommend the use of cardiac magnetic resonance imaging (MRI) for the management of atrial fibrillation (AF). However, the widespread use of cardiac MRI in clinical practice is difficult to achieve. The aim of the present study is to assess whether cardiac MRI can be adopted to identify ablation-induced fibrosis, and its relationship with AF recurrences. Fifty patients undergoing AF cryoballoon ablation were prospectively enrolled. Cardiac MRI was performed before and 30 days after the index ablation. Commercially available software and a specifically designed image processing workflow were used to quantify left atrium (LA) fibroses. Thirty-six patients were finally included in the analysis; twenty-eight were analyzed with the dedicated workflow. Acute electrical isolation was achieved in 98% of the treated pulmonary veins (PVs). After a median follow-up of 16 months, AF recurrences occurred in 12 patients (33%). In both analyses, no differences were found between the subgroups of patients with and without recurrence in the variation of either LA fibrosis or fibrosis at the ostium of the PV, before and after ablation. The ability to predict arrhythmic recurrences evaluated via the ROC curve of the variations in both LA fibrosis (AUC 0.566) and PV fibrosis (AUC 0.600) was low. Cardiac MRI holds the potential to provide clinically significant information on LA disease and AF progression; however, LA fibrosis cannot be easily identified, either by currently available commercial programs or custom tools.

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.

Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during cryoballoon ablation of atrial fibrillation: the SWEET-Cryo strategy

AIMS

Cryoballoon pulmonary vein isolation (CB-PVI) offers similar efficacy to point-by-point radiofrequency PVI for patients with atrial fibrillation (AF), but generally with higher X-ray exposure. Strategies aimed at reducing fluoroscopy mostly rely on other costly imaging techniques, limiting their applicability. We designed a Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during CB-PVI (SWEET-Cryo) strategy and analysed its impact on fluoroscopy use and acute procedural and clinical outcomes.

METHODS AND RESULTS

We enrolled 100 patients with paroxysmal or persistent AF undergoing CB-PVI by two operators with different levels of expertise. Patients treated with the SWEET-Cryo strategy (prospective cohort; n = 50) or conventional fluoroscopy (retrospective control cohort; n = 50) were compared. When applied by the senior operator, the SWEET-Cryo strategy significantly reduced the mean fluoroscopy time (FT) (2.6 ± 1.25 vs. 20.3 ± 10.8 min) and mean dose area product (DAP) (5.1 ± 3.8 vs. 35.3 ± 22.3 Gy cm2) compared with those of the control group, respectively (P < 0.001). Significant reductions in FT (6.4 ± 2.5 min vs. 32.5 ± 10.05) and DAP (13.9 ± 7.7 vs. 92.3 ± 63.8) were also achieved by the less experienced operator (P < 0.001). No difference was observed in acute and long-term complications or freedom from AF between fluoroscopy strategies during a 33-month median follow-up. Mean FT was maintained below 3 min in randomly selected cases performed during the follow-up period.

CONCLUSION

In contrast to conventional protocols and regardless of the operator's experience, the optimized SWEET-Cryo strategy dramatically reduced fluoroscopy exposure during CB-PVI. The efficacy, safety, or added costs of the ablation procedure were not compromised.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Feasibility, safety and effectiveness of mapping system assisted conduction system pacing: a single-center prospective study

To assess pacing and electrophysiological parameters, as well as mid-term outcomes, among patients undergoing His bundle pacing (HBP) guided by KODEX-EPD (a novel mapping system). Consecutive patients undergoing conduction system pacing (CSP) for bradycardia indications were evaluated. Procedural and fluoroscopic times and pacing characteristics were compared between conventional fluoroscopy (the standard group, N = 20 cases) and KODEX-EPD mapping system guided group (the KODEX group, N = 20cases) at CSP implantation and all patients were followed at 6-month. HBP was achieved in all patients (the standard group 20/20 and the KODEX group 20/20). There was no difference in the mean procedure time between the two groups (63.7 ± 9.3 vs. 78.2 ± 25.1 min, p = 0.33). Compared with the standard group, the KODEX group significantly reduced the intraoperative X-ray exposure time (3.8 ± 0.5 vs. 19.3 ± 5.1 min, p < 0.05) and X-ray dose (23.6 ± 5.4 vs. 120.2 ± 38.3 mGy, p < 0.05). There were no significant differences in atrial impedance (643.0 ± 98.8 vs. 591.5 ± 92.1 Ω, p = 0.09), atrial sensing (2.9 ± 0.8 vs. 2.5 ± 0.8 mV, p = 0.08), ventricular sensing (12.8 ± 2.4 vs. 13.3 ± 3.3 mV, p = 0.63),atrial pacing threshold (1.0 ± 0.2 vs. 1.0 ± 0.1 V/0.4 ms, p = 0.81) and ventricular pacing threshold (1.0 ± 0.2 vs. 0.9 ± 0.1 V/0.4 ms, p = 0.63) between two groups, There were statistical differences in ventricular impedance (640.0 ± 80.3 vs. 702.0 ± 86.1 Ω, p < 0.05). There was no statistical significance in pacing parameters between the two groups at 6 months after procedure (p > 0.05). During the 6-months follow-up period, no adverse events occurred in the two groups. It can be concluded that KODEX-EPD can safely guide His bundle branch pacing lead implantation with reduced fluoroscopic time and dose without lengthening the procedure time.

A Novel Case of Acute Respiratory Distress Syndrome Following Radiofrequency Ablation for Atrial Fibrillation

Radiofrequency ablation (RFA) is a minimally invasive cardiac catheterization procedure employed in patients whose atrial fibrillation (AF) is not well-controlled on medical therapy. While serious complications after the RFA are uncommon, we present the unique case of a 71-year-old male who suffered from acute respiratory distress syndrome (ARDS) and pneumomediastinum post-procedure. He presented to the ED with dyspnea, non-massive hemoptysis, and fever three days following RFA. Admission CT thorax demonstrated patchy ground glass opacities (GGOs) and stable fibrotic changes. He was admitted for suspected pneumonia, however, he failed to significantly improve on broad-spectrum antibiotics. Bronchoscopy found blood in proximal airways, however, lavage with serial aliquots were without worsening hemorrhage, ruling out suspected diffuse alveolar hemorrhage. Cytology resulted in rare iron polymorphonuclear neutrophils and no malignant cells. With worsening clinical status, the patient was eventually intubated. Repeat CT thorax showed new moderate pneumopericardium, small pneumomediastinum, and progressed GGOs. The respiratory course continued to worsen, and the patient passed away approximately one month after admission. We also present a brief literature review with the aim of identifying prognostic risk factors regarding post-RFA ARDS development. Additionally, this case identifies a novel complication of RFA, as post-procedural pneumomediastinum has not been previously described.

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.

Clinical outcome of a single procedure cryoballoon ablation for the treatment of atrial fibrillation: A real-world multicenter experience in Portugal

BACKGROUND

Cryoballoon ablation (CBA) for pulmonary vein isolation (PVI) has been growing as an alternative technique, not only in patients with paroxysmal atrial fibrillation (PAF) but also in persistent atrial fibrillation (AF). Cryoballoon ablation has demonstrated encouraging acute and mid-term results. However, data on long-term follow-up of CB-based PVI are scarce.

OBJECTIVE

We sought to examine efficacy, safety, and long-term outcomes of CBA in PAF and persistent AF in four Portuguese centers.

METHODS

All patients that were treated with the cryoballoon catheter according to routine practices with a second-generation 28-mm CB in four centers were included. This was a retrospective, non-randomized analysis. Patients were followed-up for >12 months and freedom from atrial arrhythmias (AA) was evaluated at the end of follow-up.

RESULTS

Four hundred and six patients (57.7±12.4 years, 66% men) participated. AF was paroxysmal in 326 patients (80.2%) and persistent in 80 (19.7%). The mean procedure time duration was 107.7±50.9 min, and the fluoroscopy time was 19.5±9.7 min. Procedural/periprocedural complications occurred in 30 cases (7.3%), being transient phrenic nerve palsy the most frequent incident (2 out of 3 complications). Anatomic variations of the PV were present in 16.1% of cases. At a mean follow-up of 22.0±15.0 months, 310 patients (76.3%) remained in stable sinus rhythm, with at least one AF episode recurrence documented in 98 cases (24.1%). The recurrence rate was 20.5% in the PAF group and 37.8% in the persistent AF group.

CONCLUSION

In this multicenter experience, a single CBA procedure resulted in 75.9% freedom from AF at a 22-month follow-up. This technique was demonstrated to be a safe and effective option in experienced centers for the treatment of PAF and PersAF.

Efficacy and safety of a novel cryoballoon ablation system: multicentre comparison of 1-year outcome

AIMS

The aim of the study was to compare the 1-year efficacy and safety of a novel cryoballoon (NCB) ablation system (POLARx; Boston Scientific) for pulmonary vein isolation (PVI) compared with the standard cryoballoon (SCB) system (Arctic Front, Medtronic).

METHODS AND RESULTS

Consecutive patients with atrial fibrillation (AF) undergoing PVI using the NCB and the SCB at two centres were included. We report 1-year efficacy after 12 months, short-term safety and hospitalizations within the blanking period, and predictors for AF recurrence. In case of repeat procedures, pulmonary vein (PV) reconnection patterns were characterized. Eighty patients (age 66 ± 10 years, ejection fraction 57 ± 10%, left atrial volume index 39 ± 13 mL/m2, paroxysmal AF in 64%) were studied. After a single procedure and a follow-up of 12 months, 68% in the NCB group and 70% in the SCB group showed no recurrence of AF/atrial tachycardias (P = 0.422). One patient in the NCB group suffered a periprocedural stroke with full recovery. There were no differences regarding hospitalizations during follow-up between the groups. PV reconnection observed during 12 repeat procedures (4 NCB, 8 SCB) pattern was comparable between the groups with more reconnections in the right-sided compared with the left-sided PVs.

CONCLUSION

In this multicentre study comparing two currently available cryoballoon ablation systems for PVI, no differences were observed in the efficacy and safety during a follow-up of 12 months.

Reablation in Atrial Fibrillation Recurrence and Pulmonary Vein Reconnection: Cryoballoon versus Radiofrequency as Index Ablation Procedures

Pulmonary vein (PV) isolation is a well-established rhythm control therapy in atrial fibrillation (AF). Currently, there is no consensus on which ablation technique to use for the first procedure, cryoballoon (CB) or radiofrequency (RF). A retrospective cohort study was conducted on 1055 patients who underwent a first ablation, to assess both techniques based on the need for reablation. Patients with CB (n = 557) and RF (n = 498) ablations were clinically characterized and the need for reablation during a 30-month follow-up was used as the primary endpoint. Independent variables were analyzed to identify potential predictors. The need for reablation was significantly lower in the CB group than in the RF group (hazard ratio = 0.45 and 95% confident interval = 0.32−0.61; p < 0.001); in both paroxysmal and persistent AF, using a full-adjusted regression Cox model by age, sex, smoking, hypertension, diabetes mellitus, dyslipidemia, severe obstructive sleep apnea, dilated left atrium, persistent AF and early recurrence. RF ablation, dilated left atrium, persistent AF and early recurrence were identified as independent predictors of reablation. In addition, the CB-redo subgroup had a lower PV reconnection than the RF-redo subgroup. In conclusion, CB ablation suggests a reduction in the need for reablation and lower PV reconnection during the follow-up than RF ablation.

Comparison of the acute outcome of two cryoballoon technologies for pulmonary vein isolation: An updated systematic review and meta-analysis

Initial experience suggests that the POLARx cryoballoon system (Boston Scientific) has a similar procedural efficacy and safety as Arctic Front Advance Pro (AFA-Pro, Medtronic). We performed an updated systematic review and meta-analysis comparing POLARx and AFA-Pro. Embase, MEDLINE, Web of Science, Cochrane, and Google Scholar databases were searched until 12/01/2022 for studies comparing POLARx versus AFA-Pro in patients undergoing pulmonary vein (PV) isolation for AF. A total of 8 studies, involving 1146 patients from 11 European centers were included (POLARx n = 317; AFA-Pro n = 819). There were no differences in acute PV isolation, procedure time, fluoroscopy time, ablation time, minimal esophageal temperature, and risk of phrenic nerve palsy or thromboembolic events. Balloon nadir temperatures were lower for POLARx in all PVs. Compared with AFA-Pro, POLARx had a higher rate of first freeze isolation in the left inferior PV (LIPV) (odds ratio [OR]: 2.60; 95 % confidence interval [CI]: 1.06 to 6.43; P = 0.04), higher likelihood of time-to-isolation (TTI) recording in LIPV (OR: 2.91; 95 % CI: 1.54 to 5.49; P = 0.001) and right inferior PV (OR: 3.23; 95 % CI: 1.35 to 7.74; P = 0.008). In contrast, the TTI in LIPV was longer with POLARx in comparison to AFA-Pro (mean difference: 7.61 sec; 95 % CI 2.43 to 12.8 sec; P = 0.004). In conclusion, POLARx and AFA-Pro have a similar acute outcome. Interestingly, there was a higher rate of TTI recording in the inferior PVs with POLARx. This updated meta-analysis provides new safety data on esophageal temperature and thromboembolic events.

Impact of pulmonary vein variant anatomy and cross-sectional orifice area on freedom from atrial fibrillation recurrence after cryothermal single-shot guided pulmonary vein isolation

BACKGROUND

Cryoballoon (CB)-guided pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). This study aimed to evaluate ablation efficacy and freedom from arrhythmia recurrence using the novel POLARx compared to the Arctic Front Advance Pro (AFA) CB system including the analysis of individual PV characteristics.

METHODS

A total of 687 patients underwent CB-guided ablation for AF. Arrhythmia recurrence was defined as an ECG documented episode of any AF/atrial tachycardia (AT) > 30 s. Anatomical characteristics were assessed using magnetic resonance imaging (MRI). For each PV, the cross-sectional orifice area (CSOA) was determined. Follow-up examinations were scheduled after 3, 6, and 12 months.

RESULTS

Acute PVI was achieved in all patients. Twelve-month AF-free survival was similar between the groups (POLARx 43/86 (50%) vs. AFA 318/601 (53%), Log-rank (LR) p = 0.346). MRI found a comparable percentage of patients with normal PV anatomy (POLARx 71/86 (83%) vs. AFA 530/601 (85%), p = 0.162). Patients with variant PV characteristics presented with a significantly impaired 12-month AF-free survival (normal PVs 326/585 (56%) vs. variant PVs 27/102 (27%), LR p < 0.001) independent of the applied CB ablation system. PAF patients with AF recurrence presented with significantly larger CSOA of the left-sided PVs and the right superior PVs (LSPV: p < 0.001; LIPV: p < 0.001; RSPV: p < 0.001). In PERS AF, no association between CSOA and ablation outcome was observed. Multivariate analyses identified PERS AF (hazard ratio (HR) 2.504, confidence interval (CI), 1.900-3.299, p < 0.001) and variant PV anatomy (HR 2.124, CI 1.608-2.805, p < 0.001) as independent predictors for AF recurrence.

CONCLUSIONS

Both CB ablation systems are associated with comparable 12-month AF-free survival rates. Variant PV anatomy seems to be predictive for AF recurrence. An association between CSOA and the outcome after CB-guided PVI was demonstrated for PAF.

Catheter ablation and thoracoscopic ablation in long persistent atrial fibrillation with large left atrium

Background

Pulmonary vein antrum isolation (PVAI) is the cornerstone of atrial fibrillation (AF) ablation, but the clinical outcomes of PVAI are unsatisfactory in patients with persistent AF and a large left atrium (LA).

Objectives

We investigated the clinical outcomes following radiofrequency ablation (RFCA), cryoballoon ablation (CBA), and thoracoscopic maze in patients with persistent AF and a large LA.

Methods

We included patients with consecutive persistent AF who had a large LA (LA diameter >50 mm) and underwent RFCA, CBA, or thoracoscopic maze surgery. In the RFCA group, additional linear ablation was performed at the physician’s discretion. The endpoint was 12 months without recurrence of an atrial arrhythmia, including AF, atrial flutter, and atrial tachycardia, following a 90-day blanking period.

Results

We recruited 89 persistent AF patients with a large LA who underwent RFCA (n = 32), CBA (n = 38), or the thoracoscopic maze procedure (n = 19). During the 12-month follow-up, 48 (53.9%) cases of AF recurrence were observed. There was no prognostic difference between groups (50.0% in RFCA vs. 52.6% in CBA vs. 63.2% in thoracoscopic maze, all P > 0.05). Early recurrence during the blanking period was a significant predictor of late recurrence for RFCA and CBA, but not for the thoracoscopic maze.

Conclusion

In persistent AF patients with a large LA, we did not find a prognostic difference RFCA, CBA, or a thoracoscopic maze procedure in recurrence of atrial arrhythmia. Early recurrence predicted late recurrence in catheter ablation, but not in thoracoscopic maze.

Treatment Options in AF Patients with Cancer; Focus on Catheter Ablation

Longer life expectancy along with advancements in cancer and atrial fibrillation (AF) therapies and treatment strategies have led to an increase in the number of individuals with both diseases. As a result, the complicated management of these patients has become crucial, necessitating individualised treatment that considers the bi-directional relationship between these two diseases. On the one hand, giving appropriate pharmaceutical therapy is exceptionally difficult, considering the recognised thromboembolic risk posed by AF and malignancy, as well as the haemorrhagic risk posed by cancer. The alternative pulmonary vein isolation (PVI) ablation, on the other hand, has been inadequately explored in the cancer patient population; there is yet inadequate data to allow the clinician to unambiguously select patients that can undertake this therapeutic intervention. The goal of this review is to compile the most valuable data and supporting evidence about the characteristics, care, and therapy of cancer patients with AF. Specifically, we will evaluate the pharmaceutical options for a proper anticoagulant therapy, as well as the feasibility and safety of PVI in this population.

Comparison of the Efficacy and Safety Endpoints of Five Therapies for Atrial Fibrillation: A Network Meta-Analysis

Introduction

Atrial fibrillation (AF) is a prevalent arrhythmia that occurs in 2–4% of adults and poses a threat to human health. Thus, comparison of the efficacy and safety of therapies for AF is warranted. Here, we used network analysis to compare efficacy (arrhythmia recurrence and re-hospitalization) and safety (ischemic cerebral vascular events, all-cause mortality, and cardiovascular mortality) endpoints among five major therapies for AF.

Methods

The PubMed, Cochrane, and Embase databases were searched, and relevant literature was retrieved. Only studies that made comparisons among the therapies of interest and involved patients with AF were included. Pairwise comparisons and frequentist method (SUCRA plot) analyses were conducted.

Results

In total, 62 studies were included in the pooled analysis. In pairwise comparisons, atrioventricular nodal ablation plus permanent pacemaker (AVN + PPM) was associated with a significantly higher risk of atrial arrhythmia recurrence than surgical ablation [odds ratio (OR): 23.82, 95% confidence interval (CI): 1.97–287.59, fixed-effect model; 3.82, 95% CI: 1.01–559.74, random-effects model]. Furthermore, radiofrequency ablation was associated with a significantly lower risk of cardiovascular mortality than medication in pairwise comparison (OR: 0.49, 95% CI: 0.29–0.83, fixed-effect model; OR: 0.49, 95% CI: 0.27–0.9, random-effects model). Frequentist analysis indicated that AVN + PPM had the best performance in reducing the risk of safety and efficacy endpoints.

Conclusion

Non-pharmaceutical therapies showed superior performance to traditional drug therapy in lowering the risk of safety and efficiency endpoint events. AVN + PPM performed best in reducing the risk of safety and efficacy endpoints.

Effect of air removal with extracorporeal balloon inflation on incidence of asymptomatic cerebral embolism during cryoballoon ablation of atrial fibrillation: A prospective randomized study

Background

It was previously reported, based on a retrospective study, that preliminary removal of air bubbles in heparinized saline water with extracorporeal balloon inflation reduced the incidence of asymptomatic cerebral embolism (ACE). The present study aims to compare the incidence of ACE between a conventional and pre-inflation method during cryoballoon ablation in a prospective randomized controlled study.

Methods

A total of 98 atrial fibrillation patients were enrolled and randomized into conventional and pre-inflation groups. Patients in the pre-inflation group received balloon massaging with preliminary extracorporeal balloon inflation in saline water before the cryoballoon was inserted into the body.

Results

The baseline characteristics were similar between the two groups. Post-procedural 3-Tesla MRI revealed CE in 27.6% of patients. Symptomatic CE only occurred in two patients in the pre-inflation group. One patient had transient dysarthria and mild muscle weakness in one hand; the other patient complained of transient left upper limb weakness, left lower limb paresthesia and dysarthria. The incidence of ACE detected by cerebral MRI did not differ between the two groups to a statistically significant extent (conventional vs. pre-inflation; 22.9% vs. 29.2%; P = 0.49). In the multivariable analysis, eGFR was independently associated with the presence of ACE (odds ratio 0.95; 95% confidence interval 0.907–0.995; P = 0.03).

Conclusion

In this prospective randomized study, the preliminary removal of air bubbles in heparinized saline water with extracorporeal balloon inflation had no impact on the incidence of ACE.

Catheter Ablation for Atrial Fibrillation in the Elderly > 75 Years old: Systematic Review and Meta-Analysis

INTRODUCTION

Atrial fibrillation (AF) ablation is increasingly performed worldwide. As comfort with AF ablation increases, the procedure is increasingly used in patients that are older and in those with more comorbidities. However, it is not well established whether AF ablation in the elderly, especially those >75 years old, has comparable safety and efficacy to younger populations.

OBJECTIVE

To compare the efficacy and safety profiles in patients older than 75years undergoing AF ablation with younger patients.

METHODS

Databases from EMBASE, Medline, PubMed and Cochrane, were searched from inception through September 2021. Studies that compared the success rates in AF catheter ablation and all complications rates between patients who were older vs under 75 years were included. Effect estimates from the individual studies were extracted and combined using random effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Twenty-seven observational studies were included in the analysis consisting of 363,542 patients who underwent AF ablation. Comparing patients older than 75 years old to younger patients, there was no difference in the success of ablation rates between elderly and younger patients (pooled OR 0.85: 95% CI:0.69 - 1.05, p=0.131). On the other hand, AF ablation in the elderly was associated with higher complication rates (pooled OR 1.43: 95% CI:1.21 - 1.68, p<0.001) CONCLUSION: As AF ablation is expanded to elderly populations, our study found that AF ablation success rates were similar in both elderly and younger patients. However, older patients experience higher rates of complications that should be considered when offering the procedure and as a means to improve outcomes with future innovations. This article is protected by copyright. All rights reserved.

Cryoballoon Ablation for Treatment of Atrial Fibrillation in a Chinese Population: Five-Year Outcomes and Predictors of Recurrence After a Single Procedure

Background

The 5-year outcomes and predictors of atrial fibrillation (AF) recurrence following cryoballoon (CB) ablation in Chinese population remain scarce. Our aim was to report 5-year outcomes and predictors of AF recurrence following a single CB ablation procedure in a Chinese population.

Methods

From December 2013 to August 2016, we included 256 consecutive patients (mean age: 58 ± 10.9 years old; female: 41.0%) with paroxysmal or persistent AF successfully underwent first-generation CB ablation at Fuwai hospital in this prospective study. All patients were followed at least 5 years or when there was recurrent AF. Independent predictors of AF recurrence were determined by Cox proportional hazards regression analysis.

Results

The 5-year success rate after pulmonary vein isolation (PVI) by a single procedure was 59.4%. The recurrence rate was the highest (14.5%) within the first year after the index procedure, and then stabilized. Patients with paroxysmal AF had a higher incidence of freedom from AF recurrence than patients with persistent AF (63.2% vs. 36.4%, log-rank P &lt; 0.01). The overall incidence of complications related to CB ablation was 7.8%. Phrenic nerve injury (PNI) was the most common complication, with an incidence of 3.5%, and patients with PNI were recovered within the 1-year follow-up. Only persistent AF (HR 1.72, 95%CI 1.028–2.854, P &lt; 0.05) was significantly and independently associated with an increased risk of AF recurrence after adjusting for other factors.

Conclusion

Pulmonary vein isolation using CB ablation was safe and effective with an acceptable complication and 5-year success rate in a Chinese population with AF, and persistent AF was the independent predictor for 5-year AF recurrence after a single CB ablation procedure.

Improved procedural workflow for catheter ablation of paroxysmal AF with high-density mapping system and advanced technology: Rationale and study design of a multicenter international study

BACKGROUND

The antral region of pulmonary veins (PV)s seems to play a key role in a strategy aimed at preventing atrial fibrillation (AF) recurrence. Particularly, low-voltage activity in tissue such as the PV antra and residual potential within the antral scar likely represent vulnerabilities in antral lesion sets, and ablation of these targets seems to improve freedom from AF. The aim of this study is to validate a structured application of an approach that includes the complete abolition of any antral potential achieving electrical quiescence in antral regions.

METHODS

The improveD procEdural workfLow for cathETEr ablation of paroxysmal AF with high density mapping system and advanced technology (DELETE AF) study is a prospective, single-arm, international post-market cohort study designed to demonstrate a low rate of clinical atrial arrhythmias recurrence with an improved procedural workflow for catheter ablation of paroxysmal AF, using the most advanced point-by-point RF ablation technology in a multicenter setting. About 300 consecutive patients with standard indications for AF ablation will be enrolled in this study. Post-ablation, all patients will be monitored with ambulatory event monitoring, starting within 30 days post-ablation to proactively detect and manage any recurrences within the 90-day blanking period, as well as Holter monitoring at 3, 6, 9, and 12 months post-ablation. Healthcare resource utilization, clinical data, complications, patients' medical complaints related to the ablation procedure and patient's reported outcome measures will be prospectively traced and evaluated.

DISCUSSION

The DELETE AF trial will provide additional knowledge on long-term outcome following a structured ablation workflow, with high density mapping, advanced algorithms and local impedance technology, in an international multicentric fashion. DELETE AF is registered at ClinicalTrials.gov (NCT05005143).

Two competing cryoballoon technologies for single shot pulmonary vein isolation: first experiences with the novel system

Following its introduction into clinical practice, the cryoballoon (CB) has proved to be an alternative for pulmonary vein isolation (PVI) in patients with paroxysmal and persistent atrial fibrillation (AF). In comparison with the standard radiofrequency procedure, the CB method results in a shorter procedure time and learning curve as well as a higher degree of reproducibility. A new cryoballoon (NCB) was recently introduced on the market. In this review, we addressed the following questions: Is the new system technically similar to the previous one? Is there a difference in terms of periprocedural parameters? Are acute success and complication rates similar? Is the learning curve different?

A Systematic Review and Meta-Analysis of the Direct Comparison of Second-Generation Cryoballoon Ablation and Contact Force-Sensing Radiofrequency Ablation in Patients with Paroxysmal Atrial Fibrillation

The superiority of second-generation cryoballoon (2G-CB) ablation versus contact force-sensing radiofrequency (CF-RF) ablation in patients with paroxysmal atrial fibrillation (AF) was assessed in this systematic review and meta-analysis. Freedom from atrial tachyarrhythmias (ATAs) (OR = 0.89; 95% confidence interval [CI] = 0.68 to 1.17; p = 0.41), freedom from AF (OR = 0.93; 95% CI = 0.65 to 1.35; p = 0.72), and acute pulmonary vein isolation (PVI) (OR = 1.17; 95% CI = 0.54 to 2.53; p = 0.70) between 2G-CB ablation and CF-RF ablation were not different. The procedure time for the 2G-CB ablation was shorter (MD = −18.78 min; 95% CI = −27.72 to −9.85 min; p < 0.01), while the fluoroscopy time was similar (MD = 2.66 min; 95% CI = −0.52 to 5.83 min; p = 0.10). In the 2G-CB ablation group, phrenic nerve paralysis was more common (OR = 5.74; 95% CI = 1.80 to 18.31; p = < 0.01). Regarding freedom from ATAs, freedom from AF, and acute PVI, these findings imply that 2G-CB ablation is not superior to CF-RF ablation in paroxysmal AF. Although faster than CF-RF ablation, 2G-CB ablation has a greater risk of phrenic nerve paralysis.

Comparing Efficacy and Safety in Catheter Ablation Strategies for Paroxysmal Atrial Fibrillation: A Network Meta-Analysis of Randomized Controlled Trials

Although catheter ablation (CA) is an established treatment for paroxysmal atrial fibrillation (PAF), there is no consensus regarding the most efficient CA strategy. The objective of this network meta-analysis (NMA) was to compare the efficacy and safety of different CA strategies for PAF. A systematic search was performed in PubMed, Web of Science, and CENTRAL until the final search date, 5 October 2020. Randomised controlled trials (RCT) comparing different CA strategies and methods for pulmonary vein isolation (PVI) were included. Efficacy was defined as lack of arrhythmia recurrence after CA and safety as any reported complication related to the procedure during a minimum follow-up time of six months. In total, 43 RCTs comparing 11 different CA strategies involving 6701 patients were included. The risk of recurrence was significantly decreased in comparison with PVI with radiofrequency only for the following treatments: PVI with adjuvant ablation (RR: 0.79, CI: 0.65–0.97) and PVI with sympathetic modulation (RR: 0.64, CI: 0.46–0.88). However, PVI with radiofrequency was superior to non-PVI strategies (RR: 1.65, CI: 1.2–2.26). No statistically significant difference was found in safety between different CA strategies. Concerning different PVI strategies, no difference was observed either in efficacy or in safety between tested strategies. This NMA suggests that different PVI strategies are generally similar in terms of efficacy, while PVI with additional ablation or sympathetic modulation may be more effective than PVI alone. This study provides decision-makers with insights into the efficacy and safety of different CA strategies.

Diaphragmatic CMAP Monitoring During Cryoballoon Procedures: Surface vs. Hepatic Recording Comparison and Limitations of This Approach

Background

Compound motor action potential (CMAP) monitoring is a common method used to prevent right phrenic nerve palsy during cryoballoon ablation for atrial fibrillation.

Objective

We compared recordings simultaneously obtained with surface and hepatic electrodes.

Methods

We included 114 consecutive patients (mean age 61.7 ± 10.9 years) admitted to our department for cryoballoon ablation. CMAP was monitored simultaneously with a hepatic catheter and a modified lead I ECG, whilst right phrenic nerve was paced before (stage 1) and during (stage 2) the right-sided freezes. If phrenic threat was detected with hepatic recordings (CMAP amplitude drop >30%) the application was discontinued with forced deflation.

Results

The ratio of CMAP/QRS was 4.63 (2.67–9.46) for hepatic and 0.76 (0.55–1.14) for surface (p < 0.0001). Signal coefficients of variation during stage 1 were 3.92% (2.48–6.74) and 4.10% (2.85–5.96) (p = 0.2177), respectively. Uninterpretable signals were more frequent on surface (median 10 vs. 0; p < 0.0001). For the 14 phrenic threats, the CMAP amplitude dropped by 35.61 ± 8.27% on hepatic signal and by 33.42 ± 11.58% concomitantly on surface (p = 0.5417). Our main limitation was to achieve to obtain stable phrenic capture (57%). CMAP monitoring was not reliable because of pacing instability in 15 patients (13.16%). A palsy occurred in 4 patients (3.51%) because cryoapplication was halted too late.

Conclusion

Both methods are feasible with the same signal stability and amplitude drop precocity during phrenic threats. Clarity and legibility are significantly better with hepatic recording (sharper signals, less far-field QRS). The two main limitations were pacing instability and delay between 30% CMAP decrease and cryoapplication discontinuation.