European Journal of Cardio-Thoracic Surgery Advance Access published June 18, 2015
EDITORIAL COMMENT
European Journal of Cardio-Thoracic Surgery (2015) 1–2 doi:10.1093/ejcts/ezv225
Re: Thoracoscopic surgical ablation versus catheter ablation for atrial fibrillation Mark La Meir* Department of Cardiac Surgery, UZ Brussel, Brussels, Belgium * Corresponding author. Department of Cardiac Surgery, UZ Brussel, Laarbeeklaan 101, Brussels 1090, Belgium. Tel: +32-24776008; fax: +32-24776851; e-mail: [email protected] (M. La Meir).
Keywords: Atrial fibrillation • Thoracoscopic • Video-assisted • Surgical ablation • Catheter ablation
In their paper, Phan et al. [1] studied the relative merits and risks of stand-alone surgical ablation (SA) versus percutaneous atrial fibrillation (AF) catheter ablation (CA) by performing a systematic review of the literature and a meta-analysis on the available data. Invasive treatment of AF, whether percutaneous or surgical, aims at eliminating the symptoms and the potential complications related to this arrhythmia. According to the recent guidelines, CA is useful for symptomatic paroxysmal AF refractory or intolerant to at least one Class I or III anti-arrhythmic medication when a rhythm-control strategy is desired (Class I, Level of Evidence A). For symptomatic persistent AF refractory or intolerant to at least one Class I or III anti-arrhythmic medication, AF CA is reasonable (Class IIa, Level of Evidence A) [2]. Stand-alone SA may be considered for patients who have not had a failed CA but prefer a surgical approach or for patients who have had one or more failed attempts at CA (Class IIb, Level of Evidence C) [3]. An ablation procedure in itself has a potential risk for complications related to the invasiveness of the procedure. Therefore, less invasive thoracoscopic procedures on the beating heart have been developed in an attempt to reduce potential complications, while preserving the success rates of open heart procedures. There are no studies comparing open heart maze procedures to thoracoscopic procedures. But, there are studies comparing minimally invasive thoracoscopic SA with CA for patients with AF. Phan et al. [1] did a systematic review and meta-analysis of these studies. This is the first meta-analysis of comparative studies in this field. Three of the included studies are prospectively randomized single-centre studies, and five articles were retrospective observation studies. A total of 321 video-assisted thoracoscopic SA patients are compared with 378 CA patients. Two studies treated paroxysmal AF patients, two studies treated persistent AF patients and the remainder of the studies had a mixed AF study population. Stand-alone SA was demonstrated to be superior to CA at 12-month (78 vs 53%) follow-up for freedom from arrhythmias, both on and off anti-arrhythmic drugs. This trend was maintained for both paroxysmal (82 vs 63%) and non-paroxysmal (74 vs 51%)
AF subgroups. Repeat ablations were lower in the SA group, but major complications were higher (28 vs 8%). In their discussion, the authors describe possible reasons for the higher SR rate in the SA group compared with CA. Catheter technology, a more extensive lesion set, ganglionated plexi ablation, left atrial appendage (LAA) occlusion and the included population with high numbers of redo patients are mentioned. In regard to this, it is important to acknowledge that current ablation technology, whether it is used in SA or CA, still has certain limitations in achieving continuous transmurality of the created lesions. We have demonstrated that in a single-step hybrid procedure, an endocardial touch-up of epicardial ablation lesions was necessary in 23% of patients [4]. In regard to the lesion set in CA, the recently published STAR AF2 trial showed that among patients with persistent AF, there was no reduction in the rate of recurrent AF when either linear ablation or ablation of complex fractionated electrograms was performed in addition to pulmonary vein isolation [5]. This is an important finding since more ablation lesions in CA apparently do not necessarily improve success rates. These findings could also be related to the inconsistent transmurality of lesions created by CA. The potential reconnection of linear lesions around the pulmonary veins has been demonstrated in the GAP-AF trial [6]. The higher success rates of the SA come with a higher risk of procedural adverse events. This difference was predominantly driven by higher rates of pleural effusions and pneumothorax. As seen with CA (CA of symptomatic paroxysmal AF is considered a Class 1 indication only when performed by an electrophysiologist who has received appropriate training and is performing the procedure in an experienced centre), also there is a steep-learning curve involved. This could partially explain the higher complication rate since surgeons in general have less referral for SA compared with CA by electrophysiologists. The small sample sizes and relatively short duration of follow-up are significant limitations of the majority of included studies. The reviewed articles did not mention detailed patient anticoagulation data. These data could be important because stroke prevention
© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
ADULT CARDIAC
Cite this article as: La Meir M. Re: Thoracoscopic surgical ablation versus catheter ablation for atrial fibrillation. Eur J Cardiothorac Surg 2015; doi:10.1093/ejcts/ ezv225.
2
M. La Meir / European Journal of Cardio-Thoracic Surgery
can be managed through occlusion of the LAA that could limit the need for anticoagulation [7]. The patients with higher CHAD2VASC scores could be guided towards an SA procedure, since this approach nearly always excludes or excises the LAA without leaving any intra-cardiac foreign material, a potential cause for thrombus formation [8]. Another important limitation is the lack of data on quality of life. As symptomatic improvement is a primary objective in the treatment of patients with AF, studying the quality of life should play an important role in the evaluation of ablation outcomes. Several studies have described the costs of CA of AF and few data are available on cost-effectiveness. In the process of becoming an available alternative for CA, these data should also become available for SA. The paper by Phan et al. is important because not only it gives us the necessary meta-analysis to understand the potential role of SA in the treatment of stand-alone AF, but most importantly, this paper has the potential to play a role in improving the Level of Evidence in SA. Data derived from multiple randomized clinical trials or meta-analyses will bring the Level of Evidence of stand-alone thoracoscopic ablation to a Level of Evidence A. Conflict of interest: Mark La Meir is a consultant for AtriCure.
REFERENCES [1] Phan K, Phan S, Thiagalingam A, Medi C, Yan TD. Thoracoscopic surgical ablation versus catheter ablation for atrial fibrillation. Eur J Cardiothorac Surg; in this issue. [2] January CT, Wann LS, Alpert JS, Calkins H, Cigarroa JE, Cleveland JC Jr et al. 2014 AHA/ACC/HRS guideline 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 Heart Rhythm Society. Circulation 2014;130:2071–104. [3] Calkins H, Kuck KH, Cappato R, Brugada J, Camm AJ, Chen SA et al. 2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design. Europace 2012;14:528–606. [4] Pison L, La Meir M, van Opstal J, Blaauw Y, Maessen J, Crijns HJ. Hybrid thoracoscopic surgical and transvenous catheter ablation of atrial fibrillation. J Am Coll Cardiol 2012;60:54–61. [5] Verma A, Jiang CY, Betts TR, Chen J, Deisenhofer I, Mantovan R et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med 2015;372:1812–22. [6] Kuck K. Gap-AF Trial. Breaking trial session, EHRA EUROPACE 2013, 25 June 2013, Athens, Greece. [7] Reddy VY, Sievert H, Halperin J, Doshi SK, Buchbinder M, Neuzil P et al. Percutaneous left atrial appendage closure vs warfarin for atrial fibrillation: a randomized clinical trial. JAMA 2014;312:1988–98. [8] Schiettekatte S, Czapla J, Nijs J, La Meir M. Unmasking a naked left atrial appendage closure device: a case of a silent embolic threat. Heart Rhythm 2014;11:2314–5.
EDITORIAL COMMENT
European Journal of Cardio-Thoracic Surgery (2015) 1–2 doi:10.1093/ejcts/ezv225
Re: Thoracoscopic surgical ablation versus catheter ablation for atrial fibrillation Mark La Meir* Department of Cardiac Surgery, UZ Brussel, Brussels, Belgium * Corresponding author. Department of Cardiac Surgery, UZ Brussel, Laarbeeklaan 101, Brussels 1090, Belgium. Tel: +32-24776008; fax: +32-24776851; e-mail: [email protected] (M. La Meir).
Keywords: Atrial fibrillation • Thoracoscopic • Video-assisted • Surgical ablation • Catheter ablation
In their paper, Phan et al. [1] studied the relative merits and risks of stand-alone surgical ablation (SA) versus percutaneous atrial fibrillation (AF) catheter ablation (CA) by performing a systematic review of the literature and a meta-analysis on the available data. Invasive treatment of AF, whether percutaneous or surgical, aims at eliminating the symptoms and the potential complications related to this arrhythmia. According to the recent guidelines, CA is useful for symptomatic paroxysmal AF refractory or intolerant to at least one Class I or III anti-arrhythmic medication when a rhythm-control strategy is desired (Class I, Level of Evidence A). For symptomatic persistent AF refractory or intolerant to at least one Class I or III anti-arrhythmic medication, AF CA is reasonable (Class IIa, Level of Evidence A) [2]. Stand-alone SA may be considered for patients who have not had a failed CA but prefer a surgical approach or for patients who have had one or more failed attempts at CA (Class IIb, Level of Evidence C) [3]. An ablation procedure in itself has a potential risk for complications related to the invasiveness of the procedure. Therefore, less invasive thoracoscopic procedures on the beating heart have been developed in an attempt to reduce potential complications, while preserving the success rates of open heart procedures. There are no studies comparing open heart maze procedures to thoracoscopic procedures. But, there are studies comparing minimally invasive thoracoscopic SA with CA for patients with AF. Phan et al. [1] did a systematic review and meta-analysis of these studies. This is the first meta-analysis of comparative studies in this field. Three of the included studies are prospectively randomized single-centre studies, and five articles were retrospective observation studies. A total of 321 video-assisted thoracoscopic SA patients are compared with 378 CA patients. Two studies treated paroxysmal AF patients, two studies treated persistent AF patients and the remainder of the studies had a mixed AF study population. Stand-alone SA was demonstrated to be superior to CA at 12-month (78 vs 53%) follow-up for freedom from arrhythmias, both on and off anti-arrhythmic drugs. This trend was maintained for both paroxysmal (82 vs 63%) and non-paroxysmal (74 vs 51%)
AF subgroups. Repeat ablations were lower in the SA group, but major complications were higher (28 vs 8%). In their discussion, the authors describe possible reasons for the higher SR rate in the SA group compared with CA. Catheter technology, a more extensive lesion set, ganglionated plexi ablation, left atrial appendage (LAA) occlusion and the included population with high numbers of redo patients are mentioned. In regard to this, it is important to acknowledge that current ablation technology, whether it is used in SA or CA, still has certain limitations in achieving continuous transmurality of the created lesions. We have demonstrated that in a single-step hybrid procedure, an endocardial touch-up of epicardial ablation lesions was necessary in 23% of patients [4]. In regard to the lesion set in CA, the recently published STAR AF2 trial showed that among patients with persistent AF, there was no reduction in the rate of recurrent AF when either linear ablation or ablation of complex fractionated electrograms was performed in addition to pulmonary vein isolation [5]. This is an important finding since more ablation lesions in CA apparently do not necessarily improve success rates. These findings could also be related to the inconsistent transmurality of lesions created by CA. The potential reconnection of linear lesions around the pulmonary veins has been demonstrated in the GAP-AF trial [6]. The higher success rates of the SA come with a higher risk of procedural adverse events. This difference was predominantly driven by higher rates of pleural effusions and pneumothorax. As seen with CA (CA of symptomatic paroxysmal AF is considered a Class 1 indication only when performed by an electrophysiologist who has received appropriate training and is performing the procedure in an experienced centre), also there is a steep-learning curve involved. This could partially explain the higher complication rate since surgeons in general have less referral for SA compared with CA by electrophysiologists. The small sample sizes and relatively short duration of follow-up are significant limitations of the majority of included studies. The reviewed articles did not mention detailed patient anticoagulation data. These data could be important because stroke prevention
© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
ADULT CARDIAC
Cite this article as: La Meir M. Re: Thoracoscopic surgical ablation versus catheter ablation for atrial fibrillation. Eur J Cardiothorac Surg 2015; doi:10.1093/ejcts/ ezv225.
2
M. La Meir / European Journal of Cardio-Thoracic Surgery
can be managed through occlusion of the LAA that could limit the need for anticoagulation [7]. The patients with higher CHAD2VASC scores could be guided towards an SA procedure, since this approach nearly always excludes or excises the LAA without leaving any intra-cardiac foreign material, a potential cause for thrombus formation [8]. Another important limitation is the lack of data on quality of life. As symptomatic improvement is a primary objective in the treatment of patients with AF, studying the quality of life should play an important role in the evaluation of ablation outcomes. Several studies have described the costs of CA of AF and few data are available on cost-effectiveness. In the process of becoming an available alternative for CA, these data should also become available for SA. The paper by Phan et al. is important because not only it gives us the necessary meta-analysis to understand the potential role of SA in the treatment of stand-alone AF, but most importantly, this paper has the potential to play a role in improving the Level of Evidence in SA. Data derived from multiple randomized clinical trials or meta-analyses will bring the Level of Evidence of stand-alone thoracoscopic ablation to a Level of Evidence A. Conflict of interest: Mark La Meir is a consultant for AtriCure.
REFERENCES [1] Phan K, Phan S, Thiagalingam A, Medi C, Yan TD. Thoracoscopic surgical ablation versus catheter ablation for atrial fibrillation. Eur J Cardiothorac Surg; in this issue. [2] January CT, Wann LS, Alpert JS, Calkins H, Cigarroa JE, Cleveland JC Jr et al. 2014 AHA/ACC/HRS guideline 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 Heart Rhythm Society. Circulation 2014;130:2071–104. [3] Calkins H, Kuck KH, Cappato R, Brugada J, Camm AJ, Chen SA et al. 2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design. Europace 2012;14:528–606. [4] Pison L, La Meir M, van Opstal J, Blaauw Y, Maessen J, Crijns HJ. Hybrid thoracoscopic surgical and transvenous catheter ablation of atrial fibrillation. J Am Coll Cardiol 2012;60:54–61. [5] Verma A, Jiang CY, Betts TR, Chen J, Deisenhofer I, Mantovan R et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med 2015;372:1812–22. [6] Kuck K. Gap-AF Trial. Breaking trial session, EHRA EUROPACE 2013, 25 June 2013, Athens, Greece. [7] Reddy VY, Sievert H, Halperin J, Doshi SK, Buchbinder M, Neuzil P et al. Percutaneous left atrial appendage closure vs warfarin for atrial fibrillation: a randomized clinical trial. JAMA 2014;312:1988–98. [8] Schiettekatte S, Czapla J, Nijs J, La Meir M. Unmasking a naked left atrial appendage closure device: a case of a silent embolic threat. Heart Rhythm 2014;11:2314–5.
