Cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: an updated meta-analysis of randomized and observational studies

Prospective evaluation of antral lesion size of the 31-mm size of a novel size-adjustable cryoballoon: Results of the BETTER-FIT study

Background

A novel size-adjustable cryoballoon can deliver cryotherapy with a 28- or 31-mm balloon size. However, data on antral lesion size with the 31-mm balloon size are scarce.

Objective

The purpose of this study was to evaluate the antral lesion size of cryoablation with the 31-mm balloon size.

Methods

This prospective single-center study included patients with paroxysmal atrial fibrillation undergoing first-time pulmonary vein isolation (PVI). All pulmonary veins (PVs) were first ablated with the 31-mm balloon size. The 28-mm balloon size was only used as bailout. Pre- and postablation left atrial ultrahigh-definition mapping was performed to assess the antral lesion area. Secondary outcome measures were procedural efficacy including balloon occlusion grade.

Results

Complete PVI was achieved in all 80 PVs in 20 patients (mean age 59.7 ± 10.7 years, 75% male). More than one-third of the posterior wall was ablated (35.4% ± 13.8%), and the isolated surface area was 68.7% ± 8.5%. Lateral and septal circumferential antral lesion areas were 12.1 ± 2.0 cm2 and 19.1 ± 4.7 cm2, respectively. One patient demonstrated inadvertent overlap of the antral lesions on the roof. There was a trend toward lower complete balloon occlusion in the right superior PV with the 31-mm balloon size in comparison to the 28-mm size (75% and 90%, P = .08).

Conclusion

Cryoablation with the 31-mm size of a novel size-adjustable cryoballoon results in a large antral lesion. In small atria there is the potential for leaving a small nonablated corridor on the roof when using the 31-mm balloon in both superior PVs, which may be proarrhythmogenic.

Feasibility and safety of zero-fluoro, "apron-less" approach to repeat pulmonary vein isolation procedures using radiofrequency energy after initial cryoballoon ablation

We aimed to investigate the feasibility and safety of zero-fluoro approach for the repeat atrial fibrillation (AF) procedures after initial cryoballoon (CB) ablation. We have performed a retrospective study on patients that have undergone repeat pulmonary vein isolation (PVI) procedures in our institution since zero-fluoro program was initiated in 2020. All patients received CB ablation for the initial procedure. Repeat procedures were performed under conscious sedation and with intracardiac echo (ICE) and 3D mapping system - without the use of fluoroscopy and lead aprons. We have analysed in total 50 patients (76% male, 57.9 ± 10.2 years old), 50% of which suffered from paroxysmal AF. All procedures were successfully performed without the use of fluoroscopy. The mean procedure time was 93.9 ± 27.1 min and the mean RF time was 825 ± 468 s. The mean of 0.98 ± 0.91 veins was reconnected per patient and 36% of patients did not have PV reconnections. In all patients successful PV isolation was performed, confirmed by entry and exit block. No major periprocedural complications were observed. After the mean follow up of 12.5 ± 3.4 months: 68% of mixed AF population patients were free from AF after one year. In our cohort of patients, zero-fluoro, apron-less approach for repeat PVI procedures after index cryoballoon ablation proved to be feasible and safe. Index CB ablation resulted with low rates of PV reconnections and mid-term results after repeat procedures are favourable.

Comparative safety and effectiveness of cryoballoon versus radiofrequency ablation for atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Over the past fifty years, the incidence of atrial fibrillation (AF) has tripled. Traditionally, the main treatment for this condition has been pulmonary vein isolation (PVI) performed using radiofrequency catheter ablation (RFCA). However, another technique known as cryoballoon ablation (CBA) has been developed as another option for managing this heart rhythm disorder. This study evaluated the efficacy and safety of CBA and RFCA for the treatment of AF.

METHODS

This study compared the safety and effectiveness of CBA and RFCA for the treatment of AF using a thorough review of randomized controlled trials up until June 1, 2023.

RESULTS

The results revealed that CBA and RFCA had similar effectiveness and safety profiles in achieving freedom from AF (RR: 1.00; 95% CI: 0.93 to 1.07, p = 0.99) and paroxysmal atrial fibrillation (PAF) (RR: 0.99; 95% CI: 0.89 to 1.10, p = 0.79). CBA was faster (MD =  - 23.99; 95% CI: - 32.98 to - 15.00; p < 0.00001) with a higher risk of phrenic nerve palsy (RR = 6.88; 95% CI: 3.26 to 14.50, p < 0.00001). Acute PVI rate (RR = 1.0; 95% CI: 0.99 to 1.01, p = 0.95), overall complications (RR = 1.37; 95% CI: 0.93 to 2.01, p = 0.11), pericardial effusion (RR = 0.59; 95% CI: 0.25 to 1.41, p = 0.24), and fluoroscopy time (MD = 1.63; 95% CI: - 2.06 5.32; p = 0.39) did not significantly differ between the two procedures.

CONCLUSIONS

CBA and RFCA offer similar outcomes for patients with AF and PAF, with CBA being quicker but carrying a slightly higher risk of phrenic nerve palsy.

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.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

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.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Initial clinical experience with the novel POLARx FIT cryoballoon system for pulmonary vein isolation in patients with atrial fibrillation

Background

The POLARx FIT system (Boston Scientific, MA, USA) is a novel cryoballoon (CB) ablation technology in which the balloon diameter can be expanded from 28 to 31 mm. The aim of this study was to compare the benefits and safety of the new POLARx FIT system to those of the existing POLARx system currently in use for pulmonary vein (PV) isolation (PVI) in patients with atrial fibrillation.

Methods

The first 70 consecutive patients who underwent CB-based PVI with the POLARx FIT system were retrospectively compared with 200 consecutive patients treated with the POLARx system at Sakakibara Heart Institute from October 2021 to May 2023.

Results

The POLARx FIT system yielded a higher mean ± standard deviation nadir temperature in the right inferior PV (-59.2 ± 5.29 °C vs. - 62.0 ± 5.08 °C, p = 0.006), but this required a balloon size reduction to 28 mm in 30 % of cases. No significant differences were detected in the time to isolation and thaw time of any PV between the two groups. After the CB-based PVI procedure, no residual PV carina potentials were observed with the POLARx FIT system, whereas 4/20 were with the POLARx system (p = 0.04).

Conclusions

The POLARx FIT system had comparable effectiveness and safety to the basic POLARx system. This technology may improve the ablation area, including the PV carina. However, the 31-mm balloon alone was not sufficient to isolate certain PVs.

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.

Efficacy of Catheter Ablation for Atrial Fibrillation in Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Catheter ablation (CA) has emerged as an effective therapy for AF. We conducted a meta-analysis to update the current clinical evidence on the efficacy of CA for AF in patients with HCM. We searched PubMed, Embase, Cochrane and Clinicaltrials.gov for interventional and observational studies assessing single and multiple procedure success rate of CA in HCM patients. Our meta-analysis included 25 studies involving 1817 patients. Success rate following single procedure was 40.4% (95% CI 33.1 to 48.0%) at latest follow-up. The pooled success rate following multiple procedures was 51.4% (95% CI 42.9% to 60.0%) at latest follow-up. In the subgroup analysis for AF subtype, TCA was more successful for paroxysmal AF compared to non-paroxysmal AF. For the subset of studies reporting drug-free success rate, single and multiple procedures had a success rate of 33.4% (95% CI 19.3 to 49.1%) and 51.8% (95% CI 41.3 to 62.2%) at latest follow-up, respectively. CA is a suitable option for AF in patients with HCM. Success rate is greater in paroxysmal AF, after multiple procedures and with antiarrhythmic drugs.

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

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

Radiation dose reduction in the setting of cryoballoon ablation for atrial fibrillation: the value of optimized fluoroscopy settings and intracardiac echocardiography

Cryoballoon (CB) has proven to be very effective in the percutaneous treatment of atrial fibrillation (AF). CB ablation is still hampered by X-ray exposure and the doses applied are consistently higher if compared to radiofrequency ablation. All patients who underwent CB ablation between 2015 and 2020 were analysed. Intracardiac echography was consistently used for transeptal puncture. To demonstrate the differences in radiation exposure 3 groups of 50 consecutive patients were selected. In the first group (G1) 3D rotational angiography (3DRA) was used as an intraprocedural imaging method. In the second group (G2), traditional X-ray imaging was used and frame rates both for fluoro and cine modes of diascopy were lowered. In the third group (G3) only 2-3 frames per second were used, cine mode was abandoned and the grid was removed from the X-ray detector. A total of 150 patients were included (76% males, mean age 57.3 ± 11.5 years). A dramatic reduction of radiation dose was obtained from 9585 ± 5610 µGy/m² in G1 to 2469 ± 2002 µGy/m² in G2 and finally 227.1 ± 360 µGy/m² in G3 (p < 0.0001). There was also a significant decrease of procedural and fluoroscopy times. No difference in major complications and midterm outcomes was found between the groups. By following a few relatively simple steps (omitting the pre-procedural imaging, removing grid from the X-ray detector and using very low frame rates) CB ablation could be performed with ultralow radiation exposure without compromising the safety of efficacy of the procedure.

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.

Atrial fibrillation ablation: the position of computed tomography in pre-procedural imaging

Atrial fibrillation (AF) is the most common supraventricular arrhythmia. Despite significant advances in its treatment, it still remains one of the leading causes of cardiovascular morbidity and mortality. In the last two decades, pulmonary vein isolation (PVI) was developed as the most effective treatment option. The reported effectiveness of a single ablation procedure ranges from 40% to 69% with single, and up to 88% with repeated procedures, with acceptable safety profile. The PubMed database was searched, using terms including ‘atrial fibrillation ablation’, ‘pulmonary vein isolation’, ‘computed tomography’, ‘pulmonary vein anatomy’ and ‘ovality index’. Papers were reviewed for relevance and scientific merit. Different imaging techniques are used for pre-procedural assessment of left atrial (LA) anatomy, of which computed tomography (CT) is the most common. It allows assessing pulmonary vein (PV) anatomy, the LA wall thickness in different regions and the left atrial appendage (LAA) anatomy, together with excluding the presence of intracardiac thrombi. Pre-procedural PVs imaging is important regardless of the selected ablation technique, however, cryoballoon (CB) ablation seems to be particularly anatomy-dependent. Additionally, CT also permits assessment of several PVs characteristics (geometry, dimensions, angulations, the ostium area, orientation and ovality index (OI), which are essential for the patients’ qualification and designing the strategy of AF ablation. In this paper, we have reviewed the role of CT imaging in patients undergoing ablation procedure due to recurrent/symptomatic atrial fibrillation. Moreover, we discussed the relevant literature.

Impact of very early recurrence of atrial fibrillation after cryoballoon ablation

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Treatment success and its predictors as well as the complications of catheter ablation for atrial fibrillation in a high-volume centre

PURPOSE

Catheter ablation for atrial fibrillation (AF) is a standard procedure for maintaining sinus rhythm. The aim of this study was to evaluate treatment success and its predictors and to provide quality control data on complications and redo operations in a centre with an initially a low but currently high annual volume.

METHODS

Data on patients (n = 1,253) treated with catheter ablation for AF in Tays Heart Hospital between January 2010 and May 2018 was evaluated (n = 1178 ablation-naïve patients and n = 1514 AF ablations). Comprehensive data on patient characteristics, treatment results, redo operations and complications were collected. Treatment success (maintenance of sinus rhythm at 1 year) was evaluated among patients residing within the hospital district (45% of the entire study population).

RESULTS

Treatment success was observed in approximately 62.9% of the ablation-naïve patients. Preoperative predictors of treatment success were paroxysmal AF type, previous use of antiarrhythmic drugs, left atrium diameter and age. The experience at the centre did not associate with the 1-year outcome. A relapse during the first 3-month blanking period was associated with a nine-fold risk of failure at 1 year (unadjusted OR 9.1, 95% CI 5.5-15.1, p < 0.001). The major complication rate was 4.5% (68/1514) with no deaths. Ten percent of the patients needed a redo procedure within the first year.

CONCLUSIONS

Patient-related factors are the most significant predictors of treatment success. A relapse during a 3-month blanking period is associated with a very high risk of failure at 1 year.

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.

Catheter ablation superiority over the pharmacological treatments in atrial fibrillation: a dedicated review

Atrial fibrillation globally affects roughly 33.5 million people, making it the most common heart rhythm disorder. It is a crucial arrhythmia, as it is linked with a variety of negative outcomes such as strokes, heart failure and cardiovascular mortality. Atrial fibrillation can reduce quality of life because of the potential symptoms, for instance exercise intolerance, fatigue, and palpitation. There are different types of treatments aiming to prevent atrial fibrillation and improve quality of life. Currently, the primary treatment for atrial fibrillation is pharmacology therapy, however, these still show limited effectiveness, which has led to research on other alternative strategies. Catheter ablation is considered the second line treatment for atrial fibrillation when the standard treatment has failed. Moreover, catheter ablation continues to show significant results when compared to standard therapy. Hence, this review will argue that catheter ablation can show superiority over current pharmacological treatments in different aspects. It will discuss the most influential aspects of the treatment of atrial fibrillation, which are recurrence and burden of atrial fibrillation, quality of life, atrial fibrillation in the setting of heart failure and mortality and whether catheter ablation can be the first line treatment for patients with atrial fibrillation.

Higher FT4 level within the normal range predicts the outcome of cryoballoon ablation in paroxysmal atrial fibrillation patients without structural heart disease

BACKGROUND

Accumulated evidence has indicated that a high-normal FT4 level is an independent risk factor for the clinical progression of AF. However, the association between elevated FT4 concentration within the normal range and AF recurrence after cryoballoon ablation in China is unknown.

METHODS

This retrospective and observational study included 453 AF patients who underwent cryoballoon ablation from January 2016 to August 2018. Patients were classified into quartiles based on preprocedural serum FT4 concentration. The clinical characteristics of the patients and the long-term rate of AF recurrence after ablation were assessed.

RESULTS

After a mean follow-up period of 17.4 ± 9.0 months, 91 (20.1%) patients suffered from AF recurrence. The AF recurrence rate by FT4 quartile was 17.7%, 19.0%, 21.4%, and 22.3% for participants with FT4 in quartile 1, 2, 3, and 4, respectively (p < .001). On multivariate Cox regression, FT4 concentration (HR: 1.187, 95% CI: 1.093-1.290, p < .001) and left atrial diameter (HR: 1.052, 95% CI: 1.014-1.092, p = .007) were significant predictors of AF recurrence. When stratifying for AF type, the rate of postoperative recurrence was independently increased as FT4 concentration increased in paroxysmal AF, but not in persistent AF (p < .001 in paroxysmal AF and p = .977 in persistent AF).

CONCLUSION

Higher FT4 level within the normal range predicted the outcome of cryoballoon ablation in Chinese paroxysmal AF patients without structural heart disease.

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

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

Reconnection Sites in Redo Ablation after Cryoballoon Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation

Fundamento

Na fibrilação atrial paroxística (FAP), o isolamento das veias pulmonares com criobalão (IVP-CB) tem eficácia semelhante à da ablação por radiofrequência (IVP-RF). Em procedimentos de reablação após IVP-RF, a reconexão das VPs é alta, ao passo que em pacientes com reablação após IVP-CB, as informações são escassas.

Objetivo

Determinar os locais de reconexão das VPs em pacientes que foram submetidos à reablação após IVP-CB inicial.

Métodos

Pacientes que foram submetidos a um procedimento de reablação de fibrilação atrial, após um IVP-CB inicial para FAP foram incluídos. O mapeamento eletroanatômico do AE foi utilizado. Um local de reconexão foi definido com a presença de uma voltagem de 0,3mV ou maior nas VPs e condução unidirecional ou bidirecional nas VPs durante o ritmo sinusal. Os locais de reconexão foram identificados por meio de corte paraesternal longitudinal e posteriormente ablacionados com radiofrequência.

Resultados

Dos 165 pacientes submetidos ao IVP inicial, 27 necessitaram reablações, dos quais 18 (66,6%) eram do sexo masculino, com média de idade de 55+12,3 anos. O tempo de recorrência foi de 8,9+6,4 meses. A reconexão das VPs foi encontrada em 21 (77,8%) pacientes. Houve um total de 132 lacunas de condução, seis por paciente, 3,6 por VP. Um número significativo de lacunas ocorreu na região ântero-superior da VP superior esquerda (VPSE) e nas regiões septal e inferior da VP superior direita (VPSD).

Conclusões

As VPs superiores apresentaram os locais de maior reconexão, principalmente na região anterior da VPSE e na região septal da VPSD. A razão por trás disso pode ser devido à maior espessura da parede atrial e à dificuldade em alcançar o contato de criobalão adequado.

Comparison of procedural efficacy, balloon nadir temperature, and incidence of phrenic nerve palsy between two cryoballoon technologies for pulmonary vein isolation: A systematic review and meta-analysis

Introduction

In May 2020, a novel cryoballoon system (POLARx; Boston Scientific) became available for catheter ablation of atrial fibrillation (AF). The design of the cryoballoon is comparable to the Arctic Front Advance Pro (AFA‐Pro; Medtronic), but it is more compliant during freezing. We compared the procedural efficacy, biophysical parameters, and risk of phrenic nerve palsy (PNP) between the two cryoballoons.

Methods

Embase, MEDLINE, Web of Science, Cochrane, and Google Scholar databases were searched until June 1, 2021 for relevant studies comparing POLARx versus AFA‐Pro in patients undergoing pulmonary vein isolation (PVI) for AF.

Results

A total of four studies, involving 310 patients were included. There was no difference between the two groups for outcomes regarding procedural efficacy: acute PVI (odds ratio [OR]: 0.43; 95% confidence interval [CI]: 0.06 to 3.03; p = .40), procedure time (mean difference [MD]: 8.15 min; 95% CI: −8.09 to 24.39; p = .33), fluoroscopy time (MD: 1.32 min; 95% CI: −1.61 to 4.25; p = .38) and ablation time (MD: 1.00 min; 95% CI: −0.20 to 2.20; p = .10). The balloon nadir temperature was lower for all individual pulmonary veins (PV) in POLARx compared with AFA‐Pro (MD: −9.74°C, −9.98°C, −6.72°C, −7.76°C, for left superior PV, left inferior PV, right superior PV, and right inferior PV, respectively; all p < .001). The incidence of PNP was similar between groups (OR: 0.79; 95% CI: 0.22 to 2.85; p = .72).

Conclusion

In AF patients undergoing PVI, POLARx and AFA‐Pro had a similar procedural efficacy. Balloon nadir temperatures were lower with POLARx, however, the incidence of PNP was similar.

Comparison of procedural efficacy and biophysical parameters between two competing cryoballoon technologies for pulmonary vein isolation: Insights from an initial multicenter experience

INTRODUCTION

Recently a novel cryoballoon system (POLARx, Boston Scientific) became available for the treatment of atrial fibrillation. This cryoballoon is comparable with Arctic Front Advance Pro (AFA-Pro, Medtronic), however, it maintains a constant balloon pressure. We compared the procedural efficacy and biophysical characteristics of both systems.

METHODS

One hundred and ten consecutive patients who underwent first-time cryoballoon ablation (POLARx: n = 57; AFA-Pro: n = 53) were included in this prospective cohort study.

RESULTS

Acute isolation was achieved in 99.8% of all pulmonary veins (POLARx: 99.5% vs. AFA-Pro: 100%, p = 1.00). Total procedure time (81 vs. 67 min, p < .001) and balloon in body time (51 vs. 35 min, p < .001) were longer with POLARx. After a learning curve, these times were similar. Cryoablation with POLARx was associated with shorter time to balloon temperature -30°C (27 vs. 31 s, p < .001) and -40°C (32 vs. 54 s, p < .001), lower balloon nadir temperature (-55°C vs. -47°C, p < .001), and longer thawing time till 0°C (16 vs. 9 s, p < .001). There were no differences in time-to-isolation (TTI; POLARx: 45 s vs. AFA-Pro 43 s, p = .441), however, POLARx was associated with a lower balloon temperature at TTI (-46°C vs. -37°C, p < .001). Factors associated with acute isolation differed between groups. The incidence of phrenic nerve palsy was comparable (POLARx: 3.5% vs. AFA-Pro: 3.7%).

CONCLUSION

The novel cryoballoon is comparable to AFA-Pro and requires only a short learning curve to get used to the slightly different handling. It was associated with faster cooling rates and lower balloon temperatures but TTI was similar to AFA-Pro.

Radiation exposure in cryoballoon ablation compared to radiofrequency ablation with three-dimensional electroanatomic mapping in atrial fibrillation patients

BACKGROUND

Catheter ablation for atrial fibrillation (AF) has become an established treatment to control symptoms. AF ablation either by cryoballoon or radiofrequency using three-dimensional (3D) electroanatomical mapping exposes patients and medical staff to increased doses of radiation.

AIM

To compare radiation exposure in patients during cryoballoon ablation compared to 3D electro-anatomic mapping catheter ablation in AF patients.

METHODS

A total of 30 patients referred for AF ablation underwent full history taking, 12-lead ECG, echocardiogram, and pulmonary vein isolation either by 3D mapping system or cryoballoon. Procedure duration and fluoroscopy time were collected and analyzed. Radiation exposure was measured using thermoluminescent dosimeters placed at different sites related to patients and medical staff.

RESULT

The procedural time was statistically significantly longer with 3D mapping compared to cryoballoon but showed no significant difference regarding fluoroscopy time. There was a significantly higher radiation skin dose at the right scapular area in the cryoballoon ablation group, in addition to higher peak skin dose compared to the 3D mapping ablation group. There was no statistically significant correlation between peak skin doses and fluoroscopy duration but a statistically significant correlation between peak skin dose and usage of high frame rate and the high dose area product.

CONCLUSION

Cryoballoon ablation was found to be associated with higher peak skin radiation doses especially in the right scapular area. Knowing dose area product and peak skin dose is more important than fluoroscopy time alone.

The impact of left atrium size on selection of the pulmonary vein isolation method for atrial fibrillation: Cryoballoon or radiofrequency catheter ablation

BACKGROUND

Pulmonary vein isolation (PVI) is the cornerstone of ablation strategies for atrial fibrillation (AF), and noninferiority of cryoballoon (CB) over radiofrequency (RF) ablation has been previously reported. One of the risk factors of recurrence is left atrium (LA) enlargement. This study aimed to analyze the impact of LA enlargement on the selection of CB or RF ablation for AF patients.

METHODS

A total of 2,224 AF patients (64.4 ± 10.7 years, 65.5% male) who underwent PVI were analyzed retrospectively. Left atrial diameter (LAD) and volume (LAV) were measured using echocardiography before the procedures. LA enlargement was defined as LAD ≥40 mm and LAV index (LAVI) ≥35 mL/m². Patients undergoing CB and RF ablation were propensity score matched, and 376 matched pairs were evaluated.

RESULTS

Cox proportional hazard analysis revealed that LAD (95% CI, 1.01-1.05), LAV (95% CI, 1.01-1.02), and LAVI (95% CI, 1.01-1.03) were independent predictors of recurrence. CB showed equivalent clinical outcomes to those of RF with shorter procedure time required for patients without LA enlargement. CB was inferior to RF in patients with LA enlargement (LAD, 74.5% vs 84.6%, P = .028; LAVI, 74.7% vs 83.4%, P = .015), and large LAVI was associated with a higher prevalence of non-PV foci (35% vs 29%, P = .008).

CONCLUSIONS

CB ablation may be recommended for patients without enlarged LA based on the short procedure time and efficacy, whereas RF would be more appropriate in large LAs. LAVI may be a valuable reference to predict PVI outcomes and in selecting the ablation method.

Outcomes of cryoballoon or radiofrequency ablation in symptomatic paroxysmal or persistent atrial fibrillation

Aims

To evaluate the effectiveness and safety of cryoballoon ablation (CBA) compared with radiofrequency ablation (RFA) for symptomatic paroxysmal or drug-refractory persistent atrial fibrillation (AF).

Methods and results

Prospective cluster cohort study in experienced CBA and RFA centres. Primary endpoint was ‘atrial arrhythmia recurrence’, secondary endpoints were as follows: procedural results, safety, and clinical course. A total of 4189 patients were included: CBA 2329 (55.6%) and RFA 1860 (44.4%). Cryoballoon ablation population was younger, with fewer comorbidities. Procedure time was longer in the RFA group (P = 0.01). Radiation exposure was 2487 (CBA) and 1792 cGycm² (RFA) (P < 0.001). Follow-up duration was 441 (CBA) and 511 days (RFA) (P < 0.0001). Primary endpoint occurred in 30.7% (CBA) and 39.4% patients (RFA) [adjusted hazard ratio (adjHR) 0.85, 95% confidence interval (CI) 0.70–1.04; P = 0.12). In paroxysmal AF, CBA resulted in a lower risk of recurrence (adjHR 0.80, 95% CI 0.64–0.99; P = 0.047). In persistent AF, the primary outcome was not different between groups. Major adverse cardiovascular and cerebrovascular event rates were 1.0% (CBA) and 2.8% (RFA) (adjHR 0.53, 95% CI 0.26–1.10; P = 0.088). Re-ablations (adjHR 0.46, 95% CI 0.34–0.61; P < 0.0001) and adverse events during follow-up (adjHR 0.64, 95% CI 0.48–0.88; P = 0.005) were less common after CBA. Higher rehospitalization rates with RFA were caused by re-ablations.

Conclusions

The primary endpoint did not differ between CBA and RFA. Cryoballoon ablation was completed rapidly; the radiation exposure was greater. Rehospitalization due to re-ablations and adverse events during follow-up were observed significantly less frequently after CBA than after RFA. Subgroup analysis suggested a lower risk of recurrence after CBA in paroxysmal AF.

Trial Registration

ClinicalTrials.gov (NCT01360008), https://clinicaltrials.gov/ct2/show/NCT01360008.

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

INTRODUCTION

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

METHODS AND RESULTS

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

CONCLUSION

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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

Background

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

Hypothesis

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

Method

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

Results

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

Conclusions

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

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

Purpose

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

Methods

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

Results

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

Conclusions

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

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.

Touch-up and recurrence rates after voltage mapping for verification of pulmonary vein isolation following cryoablation of paroxysmal atrial fibrillation

PURPOSE

The procedural endpoint following cryoballoon ablation (CA) for paroxysmal atrial fibrillation (PAF) is pulmonary vein isolation (PVI), which is typically confirmed by entrance/exit block using a circular mapping catheter. The present study added an assessment of ablation gaps with high-density voltage mapping after standard confirmation of PVI. Relationships between the need for touch-up ablation, patient characteristics, and atrial arrhythmia recurrence were explored.

METHODS

PAF patients received CA through standard of care treatment, with PVI assessed by bidirectional block confirmation, followed by voltage mapping. Radiofrequency ablation was performed as needed for voltage breakthrough and or additional rhythms. Freedom from atrial arrhythmia recurrence through 12-month follow-up was analyzed retrospectively with statistical survival models.

RESULTS

A total of 77 PAF patients (age 66.1 ± 11.6, CHADS₂ 1.8 ± 1.0) were followed for 1.2 ± 0.3 years after CA. During the index procedure, pulmonary vein (PV) touch-up was required in 59 patients (76.6%) and ablation of additional atrial fibrillation targets beyond PV was required in 26 patients (33.8%). Kaplan-Meier estimates of freedom from atrial arrhythmia recurrence at 1 year were 62 ± 6%. Rates were lower for patients requiring touch-up ablation (58 ± 6% vs. 78 ± 10%) or with CHADS₂ scores > 2 (33 ± 12% vs. 69 ± 6%). Cox regression models showed that the need for touch-up ablation increased recurrence (p = .045, HR = 2.6) after adjusting for hypertension and heart failure.

CONCLUSION

The high rate of PV touch-up suggests that initial CA lesions may be less durable than previously assumed, while the higher recurrence rate in patients requiring touch-up may indicate that additional factors make these patients more difficult to treat.

Single freeze per vein strategy with the second-generation cryoballoon for atrial fibrillation: a propensity score-matched study between 180- and 240-s application time in a large cohort of patients

AIMS

The single-freeze strategy using the second-generation cryoballoon (CB-A, Arctic Front Advance, Medtronic, Minneapolis, MN, USA) has been reported to be as effective as the recommended double-freeze approach in several single-centre studies. In this retrospective, international, multicentre study, we compare the 3-min single-freeze strategy with the 4-min single-freeze strategy.

METHODS AND RESULTS

Four hundred and thirty-two patients having undergone pulmonary vein isolation (PVI) by means of CB-A using a single-freeze strategy were considered for this analysis. A cohort of patients who were treated with a 3-min strategy (Group 1) was compared with a propensity score-matched cohort of patients who underwent a 4-min strategy (Group 2). Pulmonary vein isolation was successfully achieved in all the veins using the 28-mm CB-A. The procedural and fluoroscopy times were lower in Group 1 (67.8 ± 17 vs. 73.8 ± 26.3, P < 0.05; 14.9 ± 7.8 vs. 24.2 ± 10.6 min, P < 0.05). The most frequent complication was PNP, with no difference between the two groups (P = 0.67). After a mean follow-up of 13 ± 8 months, taking into consideration a blanking period of 3 months, 85.6% of patients in Group 1 and 87% of patients in Group 2 were free from arrhythmia recurrence at final follow-up (P = 0.67).

CONCLUSION

There is no difference in acute success, rate of complications, and freedom from atrial fibrillation recurrences during the follow-up between 3-min and 4-min per vein freeze strategies. The procedural and fluoroscopy times were significantly shorter in 3-min per vein strategy.

Pulmonary vein orientation is independently associated with outcomes following cryoballoon-based atrial fibrillation ablation

AIMS

Several studies have investigated the influence of pulmonary vein (PV) anatomy on outcomes of atrial fibrillation (AF) ablation. We aimed to evaluate the relationship between PV orientation and AF-free survival following cryoablation.

METHODS

160 patients scheduled for cryoablation between September 2012-March 2014 were included. Patients underwent a pre-procedural cardiac CT scan with retrospective ECG gating. PV orientation was assessed according to the position of the PV orifice relative to the sagittal plane with reference to coronal and horizontal planes.

RESULTS

160 patients (57 ± 9 years, 54% male, 33% persistent AF) were included and followed for a median of 17 (12-36) months. Excluding a blanking period of 3 months, freedom from AF after a single ablation procedure was 76%. Ventral-caudal left upper PV (p = 0.044) and ventral-caudal left lower PV orientation (p = 0.001) were more common in patients with AF recurrence. In multivariate Cox regression analysis, only left lower PV orientation [particularly dorsal-caudal (HR: 3.447, 95% CI: 1.180-10.070, p = 0.024) and ventral-caudal (HR: 3.391, 95% CI: 1.088-10.571, p = 0.035) orientations compared to dorsal-cranial orientation] as well as LA diameter (HR: 3.420, 95% CI: 1.809-6.465, p < 0.001) were significantly associated with AF recurrence.

CONCLUSION

This is the first study to demonstrate the impact of PV orientation on prediction of AF recurrence following cryoablation. Preprocedural assessment of PV orientation may modify operator preferences on treatment strategies in AF.

Radiofrequency versus Cryoballoon Ablation of Atrial Fibrillation: An Evaluation Using ECG, Holter Monitoring, and Implantable Loop Recorders to Monitor Absolute and Clinical Effectiveness

Introduction

While several studies have compared the radiofrequency current (RFC) and cryoablation for the treatment of patients with atrial fibrillation (AF), no study has monitored the long-term outcomes with the usage of implantable loop recorders (ILRs).

Methods

We enrolled 89 consecutive patients with nonvalvular paroxysmal AF (N = 44 for RFC and N = 45 for cryoballoon). The primary efficacy end point was the assessment of effectiveness for each group (RFC versus cryoballoon) when examining freedom from arrhythmia by monitoring with ECG, Holter, and implantable loop recoder (ILR). The primary safety end point compared rates of adverse events between both groups. The secondary efficacy end point examined the duration of the postablation blanking period from ILR retrieved data.

Results

The mean age of the study population was 56.6 ± 10.2 years, and the follow-up duration was 12 months. There were no differences in baseline patient characteristics between groups. At 12 months, the absolute effectiveness (measured by ILR) was 65.9% in the RFC group and 51.1% in the cryoballoon group (OR = 1.85; 95% CI: 0.79-4.35; p = 0.157), and the clinical effectiveness (measured by ECG and Holter) was 81.8% in the RFC group and 55.6% in the cryoballoon group (OR = 3.6; 95% CI: 1.37-9.46; p = 0.008). There was no difference in safety between both groups. Asymptomatic episodes were significantly more present in the RFC group as measured by ILRs (p < 0.010). In cryoballoon group, arrhythmia episodes were recorded equally irrespective of the follow-up method (i.e., ECG and Holter versus ILR (p > 0.010)). The blanking period does not seem to be as important in cryoballoon as compared to RFC.

Conclusion

RFC and cryoballoon ablation had similar absolute effectiveness at 12 months. ECG and Holter were effective when assessing the efficacy of the cryoballoon ablation; however, in the RFC group, ILR was necessary to accurately assess long-term efficacy.

Integrating new approaches to atrial fibrillation management: the 6th AFNET/EHRA Consensus Conference

There are major challenges ahead for clinicians treating patients with atrial fibrillation (AF). The population with AF is expected to expand considerably and yet, apart from anticoagulation, therapies used in AF have not been shown to consistently impact on mortality or reduce adverse cardiovascular events. New approaches to AF management, including the use of novel technologies and structured, integrated care, have the potential to enhance clinical phenotyping or result in better treatment selection and stratified therapy. Here, we report the outcomes of the 6th Consensus Conference of the Atrial Fibrillation Network (AFNET) and the European Heart Rhythm Association (EHRA), held at the European Society of Cardiology Heart House in Sophia Antipolis, France, 17-19 January 2017. Sixty-two global specialists in AF and 13 industry partners met to develop innovative solutions based on new approaches to screening and diagnosis, enhancing integration of AF care, developing clinical pathways for treating complex patients, improving stroke prevention strategies, and better patient selection for heart rate and rhythm control. Ultimately, these approaches can lead to better outcomes for patients with AF.

Retrospective review of Arctic Front Advance Cryoballoon Ablation: a multicenter examination of second-generation cryoballoon (RADICOOL trial)

BACKGROUND

Pulmonary vein isolation (PVI) via catheter ablation is an approved therapy for patients with drug-refractory and symptomatic atrial fibrillation (AF). Furthermore, cryoballoon is now considered to be as effective as focal radiofrequency catheter ablation. This study examines the second-generation cryoballoon performance in a US multicenter review of real-world practices.

METHODS

By retrospective chart collections, the long-term efficacy and safety of the cryoballoon procedure were assessed in 15 US centers. All patients had a history of drug-refractory symptomatic paroxysmal AF and were treated with a cryoballoon PVI strategy at the index ablation.

RESULTS

Four hundred fifty-two patients were evaluated, and acute PVI was achieved in 99% of patients by cryoballoon catheter ablation. In 0.88% of patients (4/452), an additional focal ablation catheter was used to achieve acute PVI during the ablation procedure. Average procedure time was 128 (range 82 to 260) min, using an average of 17 (range 1 to 19) min of fluoroscopy. The most frequent adverse event was transient phrenic nerve injury (1.5%; 7/452 patients) which all resolved by the end of the procedure with no diaphragmatic dysfunction at discharge. There were no strokes, transient ischemic attacks, cardiac tamponade, atrioesophageal fistulas, or deaths during the study. At the 12-month efficacy endpoint, single-procedure success of freedom from atrial arrhythmia was 87% (393/452 patients).

CONCLUSIONS

This real-world examination of the US practice demonstrates that second-generation cryoballoon ablation by PVI strategy is safe and effective among patients with paroxysmal AF.