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Pulmonary vein isolation without assessing pulmonary vein potentials: Not there yet
Author’s Accepted Manuscript Pulmonary vein isolation without assessing pulmonary vein potentials – not there yet Christian Sticherling, Michael Kühne, Christian Sticherling www.elsevier.com/locate/buildenv
PII: DOI: Reference:
S1547-5271(16)31163-8S1547-5271(16)31068-2 http://dx.doi.org/10.1016/j.hrthm.2016.12.007 HRTHM6949
To appear in: Heart Rhythm Cite this article as: Christian Sticherling, Michael Kühne and Christian Sticherling, Pulmonary vein isolation without assessing pulmonary vein potentials – not there yet, Heart Rhythm, http://dx.doi.org/10.1016/j.hrthm.2016.12.007 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Editorial commentary Pulmonary vein isolation without assessing pulmonary vein potentials – not there yet
Christian Sticherling, MD and Michael Kühne, MD University Hospital Basel, Switzerland
M.K. has received lecture fees and fees for proctoring from Medtronic.
Christian Sticherling, M.D. Cardiology University Hospital Basel Petersgraben 4 4031 Basel [email protected] Phone:+41-61-328 7526 Fax: +41-61-265 4598
Everything should be made as simple as possible, but not simpler -
Albert Einstein
Isolating the pulmonary veins (PVI) is the cornerstone of contemporary catheter based ablation therapy of paroxysmal atrial fibrillation (PAF) and non-longstanding persistent atrial fibrillation1, 2. Hopes to achieve similar success rates in patients with longstanding atrial fibrillation by means of modifying the substrate by creating lines or ablating putative triggers have been dampened by the negative results of the STAR-AF II trial 2. Consequently, the vast majority of electrophysiologists now only perform PVI during the first procedure. This has been traditionally carried out in a point-by-point fashion using irrigated radiofrequency ablation catheters3. The advent of contact force measurement (CFM) catheters provides more information about the catheter tissue interface4, so far without resulting in superior long-term results5. However, in contrast to single-shot devices, this modality allows for the concurrent treatment of incidental arrhythmias like atrial flutter or atrial tachycardia. Cryoballoon (CB) ablation has been introduced as a successful single shot device. Whilst the first generation balloon was more difficult to employ in certain anatomies6, the second generation balloon is more versatile, obviating the need for pre-procedural imaging for many operators. Recently, CB has been compared to radiofrequency (RF) ablation of PAF in the FIRE AND ICE trial7, 8. The trial showed no difference in the clinical outcome after a mean follow-up of 1.5 years. This result is important because from an electrophysiological standpoint the CB is a rather crude tool which does not allow for analysis of local signals. Moreover, it has been 2
shown that with the inner lumen spiral mapping catheter (ILMC; AchieveTM) used for PV assessment, recording of a real-time signal is only possible in 50% of the veins 9. The study by Iacoponi et al. in this issue of Heart Rhythm provides evidence that under certain conditions the CB ablation result is so predictable that recording PV potentials may not be necessary10. They studied a series of 52 unselected patients undergoing PVI for PAF with the second generation CB without the use of an ILMC and compared it to a propensity score matched control group of 52 patients undergoing CB ablation with the use of an ILMC. If a target temperature of -40°C was not achieved within 60 seconds of the 180 secondsfreeze, a bonus freeze was applied. In a total of 26 patients (50%) the cut-off temperature of 40°C was not achieved in at least one PV. Subsequently, a circumferential mapping catheter was advanced to the left atrium to assess the PV. In the end, 99% of the veins were isolated in 96.2% of the patients. Using this approach, the 12 months freedom of AF without antiarrhythmic drugs was high and did not differ from the group using ILMC (85% vs. 88%). The results of Iacopino et al. indicate that, in least in some patients, energy delivery can become so reliable and reproducible that proof of PVI by assessing intracardiac signals may not be necessary in the future. Data from recent trials using point-by-point RF ablation showed that by integration of CFM predictable complete isolation of the PV is possible in the majority of patients 11. However, time is not ripe yet to perform PVI without assessing PV potentials. First of all, the study was not powered for efficacy. Although unlikely, it is conceivable that a strategy using real-time signals to monitor time-to-effect could result in a higher rate of durable PVI and better outcomes. Secondly, the cut-off temperature of -40° C could not be reached in all PV in 50% of the patients. Like in all CB series, the right inferior PV proved to be the most difficult 3
to isolate. Based on the presented data, we do not know whether the chosen temperature cutoff or the time to achieve it is optimal. Due to the different catheter orientation and the location of the temperature sensor different cut-off temperatures may apply for different veins. Finally, the study is too small to address the potential for increased collateral damage (phrenic nerve palsy, atrio-oesophageal fistula) that may incur from deeper temperatures. Recent registry data indicate that PVI decreases mortality and stroke rates in AF patients12. If this observational data can be confirmed by the results of ongoing randomized controlled trials, the number of ablation procedures for PAF and non-longstanding persistent AF will continue to rise. In order to cope with a tide of PVI ablation procedures safe, easy, costeffective and quick strategies are urgently needed. CB ablation is technically less challenging than point-by-point ablation procedures. There is no need for a complex mapping system and if intracardiac signals do not have to be assessed anymore, only a simple diagnostic catheter would be needed for phrenic nerve pacing besides the CB. The work by Iacopini and colleagues shows that in some patients the use of a mapping catheter is superfluous, but there is still a long way to go before we can abandon the use of intracardiac electrograms to prove PVI.
4
References 1.
2. 3.
4.
5.
6.
7. 8.
9.
10.
11.
12.
Cosedis Nielsen J, Johannessen A, Raatikainen P, Hindricks G, Walfridsson H, Kongstad O, Pehrson S, Englund A, Hartikainen J, Mortensen LS, Hansen PS. Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation. N Engl J Med Oct 25 2012;367:1587-1595. Verma A, Jiang CY, Betts TR, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med May 7 2015;372:1812-1822. Wilber DJ, Pappone C, Neuzil P, et al. Comparison of antiarrhythmic drug therapy and radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial. JAMA Jan 27 2010;303:333-340. Reichlin T, Knecht S, Lane C, et al. Initial impedance decrease as an indicator of good catheter contact: insights from radiofrequency ablation with force sensing catheters. Heart Rhythm Feb 2014;11:194-201. Ullah W, McLean A, Tayebjee MH, Gupta D, Ginks MR, Haywood GA, O'Neill M, Lambiase PD, Earley MJ, Schilling RJ, Group** UKMT. Randomized trial comparing pulmonary vein isolation using the SmartTouch catheter with or without real-time contact force data. Heart Rhythm Sep 2016;13:1761-1767. Knecht S, Kuhne M, Altmann D, Ammann P, Schaer B, Osswald S, Sticherling C. Anatomical predictors for acute and mid-term success of cryoballoon ablation of atrial fibrillation using the 28 mm balloon. J Cardiovasc Electrophysiol Feb 2013;24:132-138. Kuck KH, Brugada J, Furnkranz A, et al. Cryoballoon or Radiofrequency Ablation for Paroxysmal Atrial Fibrillation. N Engl J Med Apr 4 2016. Kuck KH, Furnkranz A, Chun KR, et al. Cryoballoon or radiofrequency ablation for symptomatic paroxysmal atrial fibrillation: reintervention, rehospitalization, and quality-oflife outcomes in the FIRE AND ICE trial. Eur Heart J Jul 5 2016. Kuhne M, Knecht S, Altmann D, Ammann P, Schaer B, Osswald S, Sticherling C. Validation of a novel spiral mapping catheter for real-time recordings from the pulmonary veins during cryoballoon ablation of atrial fibrillation. Heart Rhythm Feb 2013;10:241-246. Iacopino S, Mugnai G, Takarada K, Paparella G, Stroker E, De Regibus V, Coutino-Moreno HE, Choudhury R, de Torres JP, Brugada P, de Asmundis C, Chierchia GB. Second Generation Cryoballoon Ablation without the Use of Real-Time Recordings: A Novel Strategy based on a Temperature Guided Approach to Ablation. Heart Rhythm Nov 18 2016. Kautzner J, Neuzil P, Lambert H, Peichl P, Petru J, Cihak R, Skoda J, Wichterle D, Wissner E, Yulzari A, Kuck KH. EFFICAS II: optimization of catheter contact force improves outcome of pulmonary vein isolation for paroxysmal atrial fibrillation. Europace Aug 2015;17:1229-1235. Friberg L, Tabrizi F, Englund A. Catheter ablation for atrial fibrillation is associated with lower incidence of stroke and death: data from Swedish health registries. Eur Heart J Aug 2016;37:2478-2487.
5
PII: DOI: Reference:
S1547-5271(16)31163-8S1547-5271(16)31068-2 http://dx.doi.org/10.1016/j.hrthm.2016.12.007 HRTHM6949
To appear in: Heart Rhythm Cite this article as: Christian Sticherling, Michael Kühne and Christian Sticherling, Pulmonary vein isolation without assessing pulmonary vein potentials – not there yet, Heart Rhythm, http://dx.doi.org/10.1016/j.hrthm.2016.12.007 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Editorial commentary Pulmonary vein isolation without assessing pulmonary vein potentials – not there yet
Christian Sticherling, MD and Michael Kühne, MD University Hospital Basel, Switzerland
M.K. has received lecture fees and fees for proctoring from Medtronic.
Christian Sticherling, M.D. Cardiology University Hospital Basel Petersgraben 4 4031 Basel [email protected] Phone:+41-61-328 7526 Fax: +41-61-265 4598
Everything should be made as simple as possible, but not simpler -
Albert Einstein
Isolating the pulmonary veins (PVI) is the cornerstone of contemporary catheter based ablation therapy of paroxysmal atrial fibrillation (PAF) and non-longstanding persistent atrial fibrillation1, 2. Hopes to achieve similar success rates in patients with longstanding atrial fibrillation by means of modifying the substrate by creating lines or ablating putative triggers have been dampened by the negative results of the STAR-AF II trial 2. Consequently, the vast majority of electrophysiologists now only perform PVI during the first procedure. This has been traditionally carried out in a point-by-point fashion using irrigated radiofrequency ablation catheters3. The advent of contact force measurement (CFM) catheters provides more information about the catheter tissue interface4, so far without resulting in superior long-term results5. However, in contrast to single-shot devices, this modality allows for the concurrent treatment of incidental arrhythmias like atrial flutter or atrial tachycardia. Cryoballoon (CB) ablation has been introduced as a successful single shot device. Whilst the first generation balloon was more difficult to employ in certain anatomies6, the second generation balloon is more versatile, obviating the need for pre-procedural imaging for many operators. Recently, CB has been compared to radiofrequency (RF) ablation of PAF in the FIRE AND ICE trial7, 8. The trial showed no difference in the clinical outcome after a mean follow-up of 1.5 years. This result is important because from an electrophysiological standpoint the CB is a rather crude tool which does not allow for analysis of local signals. Moreover, it has been 2
shown that with the inner lumen spiral mapping catheter (ILMC; AchieveTM) used for PV assessment, recording of a real-time signal is only possible in 50% of the veins 9. The study by Iacoponi et al. in this issue of Heart Rhythm provides evidence that under certain conditions the CB ablation result is so predictable that recording PV potentials may not be necessary10. They studied a series of 52 unselected patients undergoing PVI for PAF with the second generation CB without the use of an ILMC and compared it to a propensity score matched control group of 52 patients undergoing CB ablation with the use of an ILMC. If a target temperature of -40°C was not achieved within 60 seconds of the 180 secondsfreeze, a bonus freeze was applied. In a total of 26 patients (50%) the cut-off temperature of 40°C was not achieved in at least one PV. Subsequently, a circumferential mapping catheter was advanced to the left atrium to assess the PV. In the end, 99% of the veins were isolated in 96.2% of the patients. Using this approach, the 12 months freedom of AF without antiarrhythmic drugs was high and did not differ from the group using ILMC (85% vs. 88%). The results of Iacopino et al. indicate that, in least in some patients, energy delivery can become so reliable and reproducible that proof of PVI by assessing intracardiac signals may not be necessary in the future. Data from recent trials using point-by-point RF ablation showed that by integration of CFM predictable complete isolation of the PV is possible in the majority of patients 11. However, time is not ripe yet to perform PVI without assessing PV potentials. First of all, the study was not powered for efficacy. Although unlikely, it is conceivable that a strategy using real-time signals to monitor time-to-effect could result in a higher rate of durable PVI and better outcomes. Secondly, the cut-off temperature of -40° C could not be reached in all PV in 50% of the patients. Like in all CB series, the right inferior PV proved to be the most difficult 3
to isolate. Based on the presented data, we do not know whether the chosen temperature cutoff or the time to achieve it is optimal. Due to the different catheter orientation and the location of the temperature sensor different cut-off temperatures may apply for different veins. Finally, the study is too small to address the potential for increased collateral damage (phrenic nerve palsy, atrio-oesophageal fistula) that may incur from deeper temperatures. Recent registry data indicate that PVI decreases mortality and stroke rates in AF patients12. If this observational data can be confirmed by the results of ongoing randomized controlled trials, the number of ablation procedures for PAF and non-longstanding persistent AF will continue to rise. In order to cope with a tide of PVI ablation procedures safe, easy, costeffective and quick strategies are urgently needed. CB ablation is technically less challenging than point-by-point ablation procedures. There is no need for a complex mapping system and if intracardiac signals do not have to be assessed anymore, only a simple diagnostic catheter would be needed for phrenic nerve pacing besides the CB. The work by Iacopini and colleagues shows that in some patients the use of a mapping catheter is superfluous, but there is still a long way to go before we can abandon the use of intracardiac electrograms to prove PVI.
4
References 1.
2. 3.
4.
5.
6.
7. 8.
9.
10.
11.
12.
Cosedis Nielsen J, Johannessen A, Raatikainen P, Hindricks G, Walfridsson H, Kongstad O, Pehrson S, Englund A, Hartikainen J, Mortensen LS, Hansen PS. Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation. N Engl J Med Oct 25 2012;367:1587-1595. Verma A, Jiang CY, Betts TR, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med May 7 2015;372:1812-1822. Wilber DJ, Pappone C, Neuzil P, et al. Comparison of antiarrhythmic drug therapy and radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial. JAMA Jan 27 2010;303:333-340. Reichlin T, Knecht S, Lane C, et al. Initial impedance decrease as an indicator of good catheter contact: insights from radiofrequency ablation with force sensing catheters. Heart Rhythm Feb 2014;11:194-201. Ullah W, McLean A, Tayebjee MH, Gupta D, Ginks MR, Haywood GA, O'Neill M, Lambiase PD, Earley MJ, Schilling RJ, Group** UKMT. Randomized trial comparing pulmonary vein isolation using the SmartTouch catheter with or without real-time contact force data. Heart Rhythm Sep 2016;13:1761-1767. Knecht S, Kuhne M, Altmann D, Ammann P, Schaer B, Osswald S, Sticherling C. Anatomical predictors for acute and mid-term success of cryoballoon ablation of atrial fibrillation using the 28 mm balloon. J Cardiovasc Electrophysiol Feb 2013;24:132-138. Kuck KH, Brugada J, Furnkranz A, et al. Cryoballoon or Radiofrequency Ablation for Paroxysmal Atrial Fibrillation. N Engl J Med Apr 4 2016. Kuck KH, Furnkranz A, Chun KR, et al. Cryoballoon or radiofrequency ablation for symptomatic paroxysmal atrial fibrillation: reintervention, rehospitalization, and quality-oflife outcomes in the FIRE AND ICE trial. Eur Heart J Jul 5 2016. Kuhne M, Knecht S, Altmann D, Ammann P, Schaer B, Osswald S, Sticherling C. Validation of a novel spiral mapping catheter for real-time recordings from the pulmonary veins during cryoballoon ablation of atrial fibrillation. Heart Rhythm Feb 2013;10:241-246. Iacopino S, Mugnai G, Takarada K, Paparella G, Stroker E, De Regibus V, Coutino-Moreno HE, Choudhury R, de Torres JP, Brugada P, de Asmundis C, Chierchia GB. Second Generation Cryoballoon Ablation without the Use of Real-Time Recordings: A Novel Strategy based on a Temperature Guided Approach to Ablation. Heart Rhythm Nov 18 2016. Kautzner J, Neuzil P, Lambert H, Peichl P, Petru J, Cihak R, Skoda J, Wichterle D, Wissner E, Yulzari A, Kuck KH. EFFICAS II: optimization of catheter contact force improves outcome of pulmonary vein isolation for paroxysmal atrial fibrillation. Europace Aug 2015;17:1229-1235. Friberg L, Tabrizi F, Englund A. Catheter ablation for atrial fibrillation is associated with lower incidence of stroke and death: data from Swedish health registries. Eur Heart J Aug 2016;37:2478-2487.
5