Mid-to-long-term recurrence of atrial fibrillation in surgical treatment vs. catheter ablation: a meta-analysis using aggregated survival data

Introduction

Atrial fibrillation (AF) is the most common cardiac arrhythmia and leading cardiac cause of stroke, with a worldwide prevalence of 1% and up to 10% in patients undergoing cardiac surgery (1). While predominately due to an underlying cardiac condition, AF is a tachyarrhythmia caused by ectopic neuronal excitation in the atria, usually at a focus surrounding the pulmonary veins as they enter the left atrium. This stimulates unsynchronized electrical impulse firing, leading to irregular atrial contraction and turbulent blood flow. As well as reducing the effective contraction of the myocardium, thrombus formation may occur, especially in the left atrial (LA) appendage, which is responsible for resultant thromboembolic complications.

AF exists in several categories which dictate treatment and prognosis. An initial episode greater than 30 seconds without a reversible cause is not deemed significant. Two or more of these episodes followed by spontaneous termination defines “paroxysmal” AF. If a single episode persists beyond seven days, it is termed “persistent” AF. This can be further characterized as “long-standing persistent” AF if the arrhythmic episode lasts longer than one year. Finally, in the case of failed or abandoned treatment following this long-standing episode, the patient is deemed to have “permanent” AF (2,3).

While AF is usually managed in an escalatory fashion, from conservative and lifestyle intervention, to pharmacotherapy, cardioversion and finally ablation, each of these treatment modalities differs in clinical success. Within the first year, anti-arrhythmic drug (AAD) therapy has a failure rate of up to 67%, with both AF recurrence and adverse events occurring in spite of treatment (4). Catheter ablation is the next recommended treatment as per European Society of Cardiology (ESC) guidelines, with a class Ia recommendation following failed drug therapy (5). As well as catheter ablation improving quality of life outcomes, when compared to AAD therapy alone, a recent meta-analysis of six randomized controlled trials (RCT) showed only 11.8% recurrence of symptomatic arrhythmias compared to 26.4% in the AAD group (6). Alternatively, the last measure for prevention of AF recurrence is surgical intervention, which instead of disrupting aberrant signals via endocardial tissue disruption, focuses on the epicardial aspect of the heart. This can be carried out in a number of different ways. The Maze procedure, utilizing a “cut and sew” technique, as well as the newer Cox-Maze IV procedure, which instead opts for radiofrequency (RF) ablation to facilitate tissue destruction, both exist as a concomitant treatment alongside planned open surgery via sternotomy. Minimally invasive techniques are also performed, namely a totally thoracoscopic video-assisted ablation or “mini-maze”, which does not require concomitant open surgery. A robotic technique has also recently been employed to advance the existing “mini-maze” procedure. Finally, a hybrid approach can also be undertaken, usually involving a staged catheter ablation on the endocardium in the months following a surgical epicardial ablation operation (7).

The aim of this systematic review and meta-analysis was to provide a graphical amalgamation of mid-to-long-term rhythm outcomes following transcatheter and surgical intervention. We sought to directly compare the 12-month freedom from AF recurrence between these two treatment modalities using aggregated Kaplan-Meier (KM) curves.

Methods

Literature search

Three electronic databases were selected to complete the initial literature search, specifically PubMed, Embase and Cochrane Central Register of Controlled Trials, from inception of records until 16^th April 2023. The search strategy employed Medical Subject Headings (MeSH) and focused keywords, with the specific input as follows: (atrial fibrillation and (ablation or radio* or catheter or laser or cryo*) and (surgical or thorascop* or robot*)).

After removal of duplicate records and those published before the year 2000, PRISMA guidelines were followed in accordance with pre-written inclusion and exclusion criteria to screen the remaining records (8). Screening was conducted by two authors independently (J.B. and B.T.M.) with any discrepancies being finalized through team discussion, with ultimate ruling by the leading author (B.T.M.). A PRISMA diagram of the search strategy and list of records at each stage is depicted in Figure 1. Once full-text review was completed, the reference lists of all included papers were searched to assess for previously missed publications fitting the inclusion criteria.

Figure 1 PRISMA flowchart of included studies. KM, Kaplan-Meier.

Inclusion and exclusion criteria

Eligibility criteria was established a priori, and focused on inclusion of high-quality prospective studies. Only English language studies were included. Studies were included if they met the following criteria: (I) included data for AF recurrence or return to sinus rhythm at 12 months; (II) were prospective in design; (III) KM graphs of time-to-event data for AF recurrence were present, notably, with numbers-at-risk available; (IV) demographic and operative data was matched to the graphed cohort. Studies were excluded if they: (I) did not provide a KM curve; (II) had a sample size smaller than one hundred patients; (III) had overlapping cohorts with larger included studies. All conference abstracts, reviews, editorials and animal studies were also excluded.

Outcome measures

The primary outcome of this study was mid-to-long-term recurrence of AF following either surgical or catheter ablation for patients undergoing treatment for paroxysmal, persistent or permanent AF. It was a requirement for this data to be graphically depicted in included studies, using a KM curve for non-parametric survival estimation. There was no restriction on the length of follow-up for survival analysis.

The secondary outcome was procedural time with comparisons being drawn between the larger categories of surgical vs. catheter ablation as well as between subgroups of these interventions. These subgroups include thoracoscopic, cryoballoon and RF procedures.

Quality assessment

The quality of each study was assessed using the modified Canadian National Institute of Health Economics (CNIHE) assessment tool for case series (9). Of a possible total of 20 criteria to be met from the CNIHE tool, a study was considered high quality if it scored 17 or higher, moderate quality if it scored between 13 and 16, and low quality if it scored 12 or below. Study quality was independently assessed by two investigators (B.T.M. and J.B.) with review and consensus completed by the senior author (B.T.M.).

Statistical analysis

Baseline characteristics and operative details were extracted from the text, tables and figures of included papers by two independent authors (B.T.M. and J.B.). Discrepancies were discussed then finally reviewed by the senior author (B.T.M.). Statistical analysis was carried out using Stata (version 17.0, StataCorp, Texas, USA) and R (Version 4.1.1. R Core Team, Vienna, Austria) utilizing meta-analysis of proportions and means with a random-effects model where necessary. Values were considered statistically significant if the reported P value was less than 0.05. For continuous data with central tendency described using median values and interquartile range (IQR), the mean and standard deviation were estimated using calculations described by Wan and colleagues (10). Survival data were calculated using aggregated KM curves collected from included studies, where reported, using the methods described by Guyot and colleagues (11). Digitization of source KM curves was performed using DigitizeIt (version 2.5.9, Braunschweig, Germany) and in the case where multiple cohorts were represented on the same curve, individual KM curves were first generated then subsequently merged with the rest of the data, to be analyzed together.

Results

Following independent screening, 36 studies were included for analysis, of which 5 described surgical ablation and 31 reported on catheter ablation techniques (Table 1). There was considerable overlap between patient population and center-based data in published studies on this topic, and as a result, 18 papers were excluded from analysis prior to inclusion in this review.

Quality analysis using the CNIHE tool found a large majority of high-quality studies fitting all inclusion criteria, revealing 32 publications receiving scores of 17 or more and being classed as high quality. Only four studies were scored as medium quality, whilst zero included studies were low quality (Table 1). Therefore, no further sub-group analysis for outcome data or heterogeneity was required as low quality evidence was not a confounding factor in this meta-analysis.

Baseline study characteristics

Baseline cohort characteristics are reported in Table 2, along with reporting frequencies for each of the operative methods. A total of 6,700 patients were followed in this systematic review, of whom 4,863 (72.6%) were male. The studies ranged in cohort size from 100 to 611. The mean age of the overall cohort was 61.1±9.2 years with no significant difference between the surgical and catheter groups. Patient comorbidities were not reported in this review. Study details are shown in Table 1, with widespread representation from centers in Europe, Asia, North America and Australia. Most studies were multicenter, usually as part of an international clinical trial investigating catheter ablation compared to surgical or medical therapy alone. Notably, the duration of AF before intervention was substantially longer in the surgical cohort over the catheter cohort (54.9 vs. 35.6 months, respectively), suggesting a more chronic disease presentation in the surgical group. Other proxies for disease severity are reported in Table 2, including the LA diameter and left ventricular ejection fraction (LVEF). Both were more severe in the surgical group, which saw a 2.5-mm larger average LA and a 3.9% further reduced LVEF than the catheter group, at 44.8 vs. 42.3 mm and 54.0% vs. 57.9%, respectively. The apparent difference in chronicity of patient population is also reflected in the reported category of AF between groups. The surgical repair group was predominately made up of patients with persistent AF, refractive to medical therapy, while the catheter group was more evenly split, with a marginally more dominant proportion of paroxysmal AF patients.

Primary outcome: long-term freedom from AF

Freedom from AF was evaluated through meta-analysis of reported recurrence at the 12-month interval, as well as through aggregated KM survival curves created using techniques by Guyot and colleagues, which extended beyond the 5-year mark. Overall pooled freedom from AF was 71.0% (95% CI: 67.1–74.8%; I²=91.8%; Figure 2) at 12 months, with surgical and catheter subgroups attributing a freedom from AF of 77.2% (95% CI: 66.3–86.5%; I²=92.4%) and 70.0% (95% CI: 65.7–74.1%; I²=91.7%), respectively (Table 3). No significant difference was found when comparing pooled results between subgroups (P>0.05).

Figure 2 Forest plot showing freedom from atrial fibrillation at 12 months, by subgroup. ES, effect size; CI, confidence interval.

Freedom from AF recurrence at 1, 3 and 5 years for the surgical cohort was 71.7%, 57.6% and 47.6%, respectively (Figure 3). When compared to the recurrence rates of the catheter ablation cohort at 1, 3 and 5 years, which were 71.5%, 56.5% and 50.3%, respectively, no definitive conclusions could be made due to the overlapping confidence intervals when curves were superimposed (Figure 3).

Figure 3 Aggregated Kaplan-Meier curve of freedom from AF recurrence, using methods by Guyot and colleagues (11). AF, atrial fibrillation.

Secondary outcome: procedural time between groups and subgroups

The pooled procedural times for surgical vs. catheter ablation groups were 218.2 minutes (IQR: 193.1–243.4) and 169.0 minutes (IQR: 136.7–185.3), respectively. There was a non-significantly longer procedural time in the surgical group, which can be visualized in Figure 4. When comparing subgroups, specifically the type of ablation used, differences were found between the catheter ablation types. Procedural times for thoracoscopic, RF and cryoballoon ablation techniques were 218.2 minutes (IQR: 193.1–243.4), 173.9 minutes (IQR: 145.3–186.5) and 103.5 minutes (IQR: 52.6–159.2), respectively. Differences between subgroups were found to be statistically significant, specifically comparisons of procedural time between thoracoscopic and cryoballoon (P=0.002) and between RF and cryoballoon (P=0.006). Figure 5 shows the comparative difference between procedural length by subgroup.

Figure 4 Box plot showing procedural time by group.

Figure 5 Boxplot showing procedural time by subgroup. Cryo, cryoballoon; RF, radiofrequency; TS, thoracoscopic.

Differences between groups in time taken for each procedure were only found between smaller cohorts in subgroup analysis. Larger cohort comparisons showed no significant differences.

Publication bias

Our objective was to explore the possibility of publication bias using both a funnel plot and Egger’s test. However, no indication of publication bias was noted in Egger’s test following meta-analysis of outcomes (P=0.468) or in the funnel plot (Figure 6). Risk of bias was also assessed for each included study using the RoB2 tool (48) (Figure S1).

Figure 6 Funnel plot of procedural time following atrial fibrillation ablation (grouped). CI, confidence interval.

Discussion

AF is a potentially life-long condition with a variety of management options, all of varying invasiveness and effectiveness. Usually following the failure of rate control alone, as well as pharmacological rhythm control, the abnormal electrical activity is isolated from the pulmonary veins using a circumferential ablation (49). While many different types of lesion sets have been reported, including both endo- and epicardial ablation, there has been no consensus as to which pattern is most effective. This was shown in the STAR-AF II trial, a high-quality multicenter RCT involving nearly 600 patients, which compared pulmonary vein isolation (PVI) alone to PVI with addition of active areas and PVI with atrial roof ablation, showing no significant difference between lesion sets (50). Due to the variation in the characteristic abnormal electrical activity of AF, current understanding is that the level of ablation should be matched to the individual (51,52).

This meta-analysis summarized all available large prospective studies displaying adequate KM curve data for catheter and surgical cohorts, totaling 6,700 patients and 36 publications. The results of our study showed a non-significant improvement in freedom from AF recurrence at 12 months in surgical patients, with roughly 7% improvement over the endovascular alternative. High heterogeneity (I²=91.8%) and a stark imbalance in cohort size were two major factors impairing the generalizability of these results. However, patient demographic data and study endpoints were largely similar between included studies, allowing effective comparisons to be made between ablation strategies and subtypes. Due to lack of reporting, further detail into lesion set analysis, including surgical LA appendage occlusion, was not conducted and is a target for future research in this area.

The primary question to be answered in this meta-analysis was whether an epicardial lesion set showed superiority to an endocardial lesion set in preventing recurrence of AF at 12 months following initial ablation. These lesion sets correlate to surgical and catheter ablation, respectively, both of which come with their own risks and benefits. The indication for each of these approaches vary according to the guidelines published by the ESC and Society of Thoracic Surgeons (STS). According to the 2020 ESC guidelines, ordered treatment sees the implementation of catheter ablation first, recommended for rhythm control after failed drug therapy (Class I), with thoracoscopic ablation only to follow should the percutaneous approach fail (Class II) (5). The 2017 STS guidelines also only give Class I evidence for the use of surgical ablation in combination with concomitant mitral procedures or aortic valve replacement (53). This suggests that surgical ablation patients may have more complex pathology or be subject to additional co-morbidities resulting in initial failure of prior medical and ablative therapy. Catheter ablation, however, received an ESC Class I indication for initial therapy for patients refractory to anti-arrhythmic medication alone, provided the operator was skilled and the procedure was undertaken in an experienced center (5). The implication of these guideline recommendations is reflected in the results of this meta-analysis, which saw a cohort of surgical candidates with a potentially higher degree of co-morbidities perform just as well as the catheter ablation candidates. Moreover, four of the five included surgical cohorts reported failed previous catheter ablation in a proportion of their patients (12,13,15,16), whereas none of the 31 catheter ablation papers reported this variable. The reported surgical group had a more chronic AF duration, larger LA diameter and poorer LVEF (Table 2), yet showed almost identical long-term freedom from recurrence when overlaid on the aggregated KM curve of the catheter group in Figure 3. This time-to-event data reconstruction represents the largest in current literature and also provides a graphical comparison of long-term freedom from recurrence between catheter and surgical ablation cohorts.

Despite the potential for more extensive coverage of ablation, the procedural time for surgical ablation was not significantly different to the catheter ablation cohort (Figure 4). A previous meta-analysis revealed a difference between these groups in a smaller cohort and with fewer studies selected, however this statistically significant finding was lost when correcting for high heterogeneity in a leave-one-out analysis (54). When isolating length of procedure by ablation technique, the cryoballoon ablation was significantly shorter than both RF and thoracoscopic alternatives (P=0.006 and P=0.002, respectively). This is consistent with findings from Mörtsell et al., who conducted a large analysis of 4,657 patients from Swedish and European Heart Rhythm Association registries, showing a 41-minute reduction in procedural time between cryoballoon and RF cohorts (P<0.001) (55).

It should be noted that a single hybrid ablation study was included under the ’surgical’ group in our analysis and aided in the reduction of the overall procedural time for this group. The paper in question, the CONVERGE trial by DeLurgio et al., found that during hybrid procedures conducted in 102 patients, the epicardial ablation time was only 42.9±13.7 minutes compared to the 135.8±49.9 minutes of the endocardial portion of the procedure (14). While this study showed no superiority in AF recurrence over others included in this analysis, at 29.4% at 12 months post-op, it poses an interesting opportunity for future analysis when compared to traditional catheter and surgical ablation techniques. Hybrid ablation may not only be able to more completely isolate conductive tissue in the atria, but also may be able to reach areas, such as Bachmann’s bundle, which are more difficult to access without it (56). It appears that hybrid ablation may have benefits for AF-free survival and reduced re-operation rates, however it is yet to be definitively proven in the literature (57).

Limitations

This meta-analysis was not free from limitations, and was most prominently restricted by relative underreporting of surgical patients compared to catheter ablation patients. The discrepancy in patient populations, shown graphically by the wider confidence interval in Figure 3, reveals the necessity for further high-quality research to be performed in this cohort. There was also heterogeneity in the ablation technique between studies of the same group for analysis. In the surgical group, included studies used either mini-thoracotomy, thoracoscopy or hybrid ablation, limiting the homogeneity of combined results. In the catheter group, studies reported RF, cryoballoon or mixed cohorts, with similar issues in combined data validity. Finally, when creating the aggregated KM curves, data were obtained from estimated patient data as opposed to real data provided individually by each author. This accounts for the slight error between total patients in Table 2 and numbers at risk in Figure 3.

Conclusions

As depicted in the provided composite KM curve, this systematic review and meta-analysis has shown that despite potentially more complex disease, surgical ablation patients have non-inferior long-term AF recurrence when compared to those undergoing catheter ablation. Recurrence at 12 months as well as procedural time are also similar between these groups, yet with the development of both technologies currently underway and into the future, improvement of these endpoints will likely continue. Ultimately, both ablation methods were able to prevent recurrence of AF in approximately 50% of patients at five years following the procedure.

Acknowledgments

Funding: None.

Footnote

Conflicts of Interest: The authors have no conflicts of interest to declare.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Markides V, Schilling RJ. Atrial fibrillation: classification, pathophysiology, mechanisms and drug treatment. Heart 2003;89:939-43. [Crossref] [PubMed]
2. European Heart Rhythm Association. ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation--executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation). J Am Coll Cardiol 2006;48:854-906. Erratum in: J Am Coll Cardiol 2007;50:562. [Crossref] [PubMed]
3. January CT, Wann LS, Calkins H, et al. 2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society in Collaboration With the Society of Thoracic Surgeons. Circulation 2019;140:e125-51. [Crossref] [PubMed]
4. Valembois L, Audureau E, Takeda A, et al. Antiarrhythmics for maintaining sinus rhythm after cardioversion of atrial fibrillation. Cochrane Database Syst Rev 2019;9:CD005049. [Crossref] [PubMed]
5. Hindricks G, Potpara T, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Eur Heart J 2021;42:373-498. [Crossref] [PubMed]
6. Turagam MK, Musikantow D, Whang W, et al. Assessment of Catheter Ablation or Antiarrhythmic Drugs for First-line Therapy of Atrial Fibrillation: A Meta-analysis of Randomized Clinical Trials. JAMA Cardiol 2021;6:697-705. [Crossref] [PubMed]
7. Wolf RK. Surgical Treatment of Atrial Fibrillation. Methodist Debakey Cardiovasc J 2021;17:56-64. [Crossref] [PubMed]
8. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372: [Crossref] [PubMed]
9. Moga C, Guo B, Schopflocher D, et al. Development of a Quality Appraisal Tool for Case Series Studies Using a Modified Delphi Technique. Edmonton AB: Institute of Health Economics; 2012.
10. Wan X, Wang W, Liu J, et al. Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range. BMC Med Res Methodol 2014;14:135. [Crossref] [PubMed]
11. Guyot P, Ades AE, Ouwens MJ, et al. Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves. BMC Med Res Methodol 2012;12:9. [Crossref] [PubMed]
12. Ad N, Holmes SD, Friehling T. Minimally Invasive Stand-Alone Cox Maze Procedure for Persistent and Long-Standing Persistent Atrial Fibrillation: Perioperative Safety and 5-Year Outcomes. Circ Arrhythm Electrophysiol 2017;10:e005352. [Crossref] [PubMed]
13. Baalman SWE, van den Berg NWE, Neefs J, et al. Left atrial strain and recurrence of atrial fibrillation after thoracoscopic surgical ablation: a subanalysis of the AFACT study. Int J Cardiovasc Imaging 2022;38:2615-24. [Crossref] [PubMed]
14. DeLurgio DB, Crossen KJ, Gill J, et al. Hybrid Convergent Procedure for the Treatment of Persistent and Long-Standing Persistent Atrial Fibrillation: Results of CONVERGE Clinical Trial. Circ Arrhythm Electrophysiol 2020;13:e009288. [Crossref] [PubMed]
15. Neefs J, Wesselink R, van den Berg NWE, et al. Thoracoscopic surgical atrial fibrillation ablation in patients with an extremely enlarged left atrium. J Interv Card Electrophysiol 2022;64:469-78. [Crossref] [PubMed]
16. Saini A, Hu YL, Kasirajan V, et al. Long-term outcomes of minimally invasive surgical ablation for atrial fibrillation: A single-center experience. Heart Rhythm 2017;14:1281-8. [Crossref] [PubMed]
17. Boveda S, Metzner A, Nguyen DQ, et al. Single-Procedure Outcomes and Quality-of-Life Improvement 12 Months Post-Cryoballoon Ablation in Persistent Atrial Fibrillation: Results From the Multicenter CRYO4PERSISTENT AF Trial. JACC Clin Electrophysiol 2018;4:1440-7. [Crossref] [PubMed]
18. Buist TJ, Adiyaman A, Smit JJJ, et al. Arrhythmia-free survival and pulmonary vein reconnection patterns after second-generation cryoballoon and contact-force radiofrequency pulmonary vein isolation. Clin Res Cardiol 2018;107:498-506. [Crossref] [PubMed]
19. Chun JKR, Bordignon S, Last J, et al. Cryoballoon Versus Laserballoon: Insights From the First Prospective Randomized Balloon Trial in Catheter Ablation of Atrial Fibrillation. Circ Arrhythm Electrophysiol 2021;14:e009294. [Crossref] [PubMed]
20. Deftereos S, Giannopoulos G, Efremidis M, et al. Colchicine for prevention of atrial fibrillation recurrence after pulmonary vein isolation: mid-term efficacy and effect on quality of life. Heart Rhythm 2014;11:620-8. [Crossref] [PubMed]
21. Di Biase L, Mohanty P, Mohanty S, et al. Ablation Versus Amiodarone for Treatment of Persistent Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted Device: Results From the AATAC Multicenter Randomized Trial. Circulation 2016;133:1637-44. [Crossref] [PubMed]
22. Gal P, Aarntzen AE, Smit JJ, et al. Conventional radiofrequency catheter ablation compared to multi-electrode ablation for atrial fibrillation. Int J Cardiol 2014;176:891-5. [Crossref] [PubMed]
23. Giannopoulos G, Vrachatis D, Kossyvakis C, et al. Effect of Postablation Statin Treatment on Arrhythmia Recurrence in Patients With Paroxysmal Atrial Fibrillation. J Cardiovasc Pharmacol 2018;72:285-90. [Crossref] [PubMed]
24. Inoue K, Hikoso S, Masuda M, et al. Pulmonary vein isolation alone vs. more extensive ablation with defragmentation and linear ablation of persistent atrial fibrillation: the EARNEST-PVI trial. Europace 2021;23:565-74. [Crossref] [PubMed]
25. Jiang R, Chen M, Fan J, et al. Efficacy of ablation index-guided pulmonary vein isolation in patients with paroxysmal atrial fibrillation. Pacing Clin Electrophysiol 2022;45:1186-93. [Crossref] [PubMed]
26. Kang KW, Pak HN, Park J, et al. Additional linear ablation from the superior vena cava to right atrial septum after pulmonary vein isolation improves the clinical outcome in patients with paroxysmal atrial fibrillation: prospective randomized study. Europace 2014;16:1738-45. [Crossref] [PubMed]
27. Kistler PM, Chieng D, Sugumar H, et al. Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The CAPLA Randomized Clinical Trial. JAMA 2023;329:127-35. [Crossref] [PubMed]
28. Kuniss M, Pavlovic N, Velagic V, et al. Cryoballoon ablation vs. antiarrhythmic drugs: first-line therapy for patients with paroxysmal atrial fibrillation. Europace 2021;23:1033-41. [Crossref] [PubMed]
29. Lee JM, Shim J, Park J, et al. The Electrical Isolation of the Left Atrial Posterior Wall in Catheter Ablation of Persistent Atrial Fibrillation. JACC Clin Electrophysiol 2019;5:1253-61. [Crossref] [PubMed]
30. Lee KN, Roh SY, Baek YS, et al. Long-Term Clinical Comparison of Procedural End Points After Pulmonary Vein Isolation in Paroxysmal Atrial Fibrillation: Elimination of Nonpulmonary Vein Triggers Versus Noninducibility. Circ Arrhythm Electrophysiol 2018;11:e005019. [Crossref] [PubMed]
31. Macle L, Khairy P, Weerasooriya R, et al. Adenosine-guided pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation: an international, multicentre, randomised superiority trial. Lancet 2015;386:672-9. [Crossref] [PubMed]
32. Marrouche NF, Wazni O, McGann C, et al. Effect of MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The DECAAF II Randomized Clinical Trial. JAMA 2022;327:2296-305. [Crossref] [PubMed]
33. McLellan AJ, Ling LH, Azzopardi S, et al. A minimal or maximal ablation strategy to achieve pulmonary vein isolation for paroxysmal atrial fibrillation: a prospective multi-centre randomized controlled trial (the Minimax study). Eur Heart J 2015;36:1812-21. [Crossref] [PubMed]
34. Packer DL, Kowal RC, Wheelan KR, et al. Cryoballoon ablation of pulmonary veins for paroxysmal atrial fibrillation: first results of the North American Arctic Front (STOP AF) pivotal trial. J Am Coll Cardiol 2013;61:1713-23. [Crossref] [PubMed]
35. Pokushalov E, Romanov A, Katritsis DG, et al. Ganglionated plexus ablation vs linear ablation in patients undergoing pulmonary vein isolation for persistent/long-standing persistent atrial fibrillation: a randomized comparison. Heart Rhythm 2013;10:1280-6. [Crossref] [PubMed]
36. Rillig A, Schmidt B, Di Biase L, et al. Manual Versus Robotic Catheter Ablation for the Treatment of Atrial Fibrillation: The Man and Machine Trial. JACC Clin Electrophysiol 2017;3:875-83. [Crossref] [PubMed]
37. Spitzer SG, Miller JM, Sommer P, et al. Randomized evaluation of redo ablation procedures of atrial fibrillation with focal impulse and rotor modulation-guided procedures: the REDO-FIRM study. Europace 2023;25:74-82. [Crossref] [PubMed]
38. Steinberg JS, Shabanov V, Ponomarev D, et al. Effect of Renal Denervation and Catheter Ablation vs Catheter Ablation Alone on Atrial Fibrillation Recurrence Among Patients With Paroxysmal Atrial Fibrillation and Hypertension: The ERADICATE-AF Randomized Clinical Trial. JAMA 2020;323:248-55. [Crossref] [PubMed]
39. Sun J, Chen M, Wang Q, et al. Adding six short lines on pulmonary vein isolation circumferences reduces recurrence of paroxysmal atrial fibrillation: Results from a multicenter, single-blind, randomized trial. Heart Rhythm 2022;19:344-51. [Crossref] [PubMed]
40. Valderrábano M, Peterson LE, Swarup V, et al. Effect of Catheter Ablation With Vein of Marshall Ethanol Infusion vs Catheter Ablation Alone on Persistent Atrial Fibrillation: The VENUS Randomized Clinical Trial. JAMA 2020;324:1620-8. [Crossref] [PubMed]
41. Wintgens LIS, Klaver MN, Maarse M, et al. Efficacy and safety of the GOLD FORCE multicentre randomized clinical trial: multielectrode phased radiofrequency vs. irrigated radiofrequency single-tip catheter with contact force ablation for treatment of symptomatic paroxysmal atrial fibrillation. Europace 2021;23:1931-8. [Crossref] [PubMed]
42. Wu G, Huang H, Cai L, et al. Long-term observation of catheter ablation vs. pharmacotherapy in the management of persistent and long-standing persistent atrial fibrillation (CAPA study). Europace 2021;23:731-9. [Crossref] [PubMed]
43. Yang B, Jiang C, Lin Y, et al. STABLE-SR (Electrophysiological Substrate Ablation in the Left Atrium During Sinus Rhythm) for the Treatment of Nonparoxysmal Atrial Fibrillation: A Prospective, Multicenter Randomized Clinical Trial. Circ Arrhythm Electrophysiol 2017;10:e005405. [Crossref] [PubMed]
44. Yao RJR, Macle L, Deyell MW, et al. Impact of Female Sex on Clinical Presentation and Ablation Outcomes in the CIRCA-DOSE Study. JACC Clin Electrophysiol 2020;6:945-54. [Crossref] [PubMed]
45. Xu Q, Ju W, Xiao F, et al. Circumferential pulmonary vein antrum ablation for the treatment of paroxysmal atrial fibrillation: A randomized controlled trial. Pacing Clin Electrophysiol 2020;43:280-8. [Crossref] [PubMed]
46. Yu HT, Shin DG, Shim J, et al. Unilateral versus Bilateral Groin Puncture for Atrial Fibrillation Ablation: Multi-Center Prospective Randomized Study. Yonsei Med J 2019;60:360-7. [Crossref] [PubMed]
47. Poole JE, Bahnson TD, Monahan KH, et al. Recurrence of Atrial Fibrillation After Catheter Ablation or Antiarrhythmic Drug Therapy in the CABANA Trial. J Am Coll Cardiol 2020;75:3105-18. [Crossref] [PubMed]
48. Sterne JAC, Savović J, Page MJ, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials. BMJ 2019;366:l4898. [Crossref] [PubMed]
49. Katritsis G, Calkins H. Catheter Ablation of Atrial Fibrillation - Techniques and Technology. Arrhythm Electrophysiol Rev 2012;1:29-33. [Crossref] [PubMed]
50. Verma A, Jiang CY, Betts TR, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med 2015;372:1812-22. [Crossref] [PubMed]
51. Rolf S, Kircher S, Arya A, et al. Tailored atrial substrate modification based on low-voltage areas in catheter ablation of atrial fibrillation. Circ Arrhythm Electrophysiol 2014;7:825-33. [Crossref] [PubMed]
52. Johner N, Namdar M, Shah DC. Individualised Approaches for Catheter Ablation of AF: Patient Selection and Procedural Endpoints. Arrhythm Electrophysiol Rev 2019;8:184-90. [Crossref] [PubMed]
53. Badhwar V, Rankin JS, Damiano RJ Jr, et al. The Society of Thoracic Surgeons 2017 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation. Ann Thorac Surg 2017;103:329-41. [Crossref] [PubMed]
54. Yonas E, Pranata R, Siswanto BB, et al. Comparison between surgical and catheter based ablation in atrial fibrillation, should surgical based ablation be implemented as first line? - A meta-analysis of studies. Indian Pacing Electrophysiol J 2020;20:14-20. [Crossref] [PubMed]
55. Mörtsell D, Arbelo E, Dagres N, et al. Cryoballoon vs. radiofrequency ablation for atrial fibrillation: a study of outcome and safety based on the ESC-EHRA atrial fibrillation ablation long-term registry and the Swedish catheter ablation registry. Europace 2019;21:581-9. [Crossref] [PubMed]
56. Nasso G, Lorusso R, Moscarelli M, et al. Catheter, surgical, or hybrid procedure: what future for atrial fibrillation ablation? J Cardiothorac Surg 2021;16:186. [Crossref] [PubMed]
57. Marchlinski F, Kumareswaran R. Hybrid Ablation for Atrial Fibrillation: Better or Just Different? JACC Clin Electrophysiol 2017;3:350-2. [Crossref] [PubMed]