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Predictors and Characteristics of Multiple (More Than 2) Catheter Ablation Procedures for Atrial Fibrillation LI-WEI LO, M.D.,∗ ,† YENN-JIANG LIN, M.D.,∗ ,† SHIH-LIN CHANG, M.D.,∗ ,† YU-FENG HU, M.D.,∗ ,† TZE-FAN CHAO, M.D.,∗ ,† FA-PO CHUNG, M.D.,∗ ,† JO-NAN LIAO, M.D.,∗ ,† CHEUN-WANG CHIOU, M.D.,∗ ,† HSUAN-MING TSAO, M.D.,†,‡ and SHIH-ANN CHEN, M.D.∗ ,† From the ∗ Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; †Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan; and ‡National Yang-Ming University Hospital, Ilan, Taiwan
Characteristics of Multiple AF Ablation Procedures. Background: The recurrence of atrial fibrillation (AF) is not uncommon in the era of catheter ablation. This study aimed to evaluate the characteristics of AF patients who underwent multiple (>2) ablation procedures. Methods and Results: Of 666 consecutive patients (53 ± 11 y/o, 484 men) who underwent catheter ablation of AF (paroxysmal AF, n = 530), 144 (22%) underwent 2 procedures and 52 (8%) underwent more than 2 procedures due to symptomatic recurrences refractory to medication during 48 ± 23 months of follow-up. Baseline and procedural characteristics at the index procedure were investigated to determine their impact on the necessity of multiple procedures. After 2 procedures, 48 (92%) of 52 patients had pulmonary vein (PV) ectopic beats initiating AF. Coexisting PV and non-PV triggers were found in 23 of 48 patients. In a multivariate analysis, the presence of non-PV triggers (P = 0.004; odds ratio 2.69, 95% CI 1.37–5.28) at the index procedure was the only independent predictor of necessary multiple procedures. Among patients with non-PV ectopic beats initiating AF at the index procedure, the presence of ligament of Marshall triggers (P = 0.001, odds ratio 6.74, 95% CI 2.13–21.32) could predict the necessity of multiple procedures. Conclusions: The need for multiple catheter ablation procedures can be predicted by the presence of non-PV ectopic beats initiating AF at the index procedure. However, PV-initiated AF remains the major cause of AF recurrence despite multiple catheter ablation procedures. (J Cardiovasc Electrophysiol, Vol. 26, pp. 1048-1056, October 2015) atrial fibrillation, catheter ablation, nonpulmonary vein ectopy, pulmonary vein isolation, recurrence Introduction A decade ago, catheter ablation of atrial fibrillation (AF) was introduced as a method of maintaining sinus rhythm.1,2 The past 10 years of AF ablation have been characterized by a better understanding of the mechanisms of AF and by the evolution of new concepts associated with technological innovations. The updated worldwide survey of catheter ablation for AF reported that catheter ablation is effective in approximately 80% of patients after 1.3 procedures.3 Recently, long-term follow-up results after catheter ablation have been reported, and the single procedure results are not satisfactory. Ouyang et al. reported that in the majority of paroxysmal AF patients with normal left ventricular function, The present work was supported by the Taipei Veterans General Hospital (V101B-010, V102B-002, V102E7-003, V103C-042, V103C-126, V103E7-002, VGHUST103-G1-3-1), Ministry of Science and Technology (NSC100-2314-B-075-054-MY3, NSC 101-2911-I-008-001, NSC1022325-B-010-005, MOST 103-2314-B-075-062-MY3), and Research Foundation of Cardiovascular Medicine (RFCM 100-02-011, 101-01-001).
only 47% remained in stable sinus rhythm 4.8 years after circumferential pulmonary vein (PV) isolation.4 The Bordeaux group reported that the AF-free survival rate after a single ablation procedure was only 29% after 5 years.5 Similarly, studies from the Taipei and Hamburg groups reported longterm recurrence-free rates lower than 30% in nonparoxysmal AF patients after a single ablation procedure.6,7 Patients with AF originating from non-PV ectopy have worse outcomes than patients with PV ectopy alone.8 A portion of patients require multiple procedures. It has been reported that PV connections are the major cause of AF recurrences despite multiple (>2) ablation procedures. Repeat PV isolation can effectively eliminate the AF with a satisfactory outcome.9 Recently, a study from Lin et al. also reported the importance of repeat PV isolation and non-PV triggers during recurrence after multiple repeat procedures.10 However, predictors in patients who require multiple ablation procedures have not been previously clarified. Thus, the aim of this study was to evaluate characteristics and predictors in AF patients who received multiple (>2) ablation procedures.
Disclosures: None. Address for correspondence: Shih-Ann Chen, M.D., Division of Cardiology, Taipei Veterans General Hospital, 201, Sec. 2, Shih-Pai Road, Taipei, Taiwan. Fax: 886-2-2873-5656; E-mail: [email protected] Manuscript received 21 April 2015; Revised manuscript received 13 June 2015; Accepted for publication 17 June 2015. doi: 10.1111/jce.12748
Methods Patient Population Of 666 consecutive AF patients (paroxysmal/nonparo xysmal 530/136) who underwent catheter ablation, 144 (22%) received 2 procedures and 52 (8%) received more than 2 procedures due to symptomatic recurrences refractory to medication. During the index and repeat
Lo et al.
procedures, the same mapping (electroanatomical mapping using NavX, St. Jude Medical, St. Paul, MN, USA) and ablation techniques were used in all patients. Paroxysmal AF was defined as AF of less than 7 days’ duration while chronic AF included patients with persistent (sustained beyond 7 days) and long-lasting persistent (continuous AF for more than 1 year) AF.11 The study protocol was reviewed and approved by the hospital’s institutional review board. Patients were divided into 2 groups: group 1 comprised patients who received 1 or 2 procedures and group 2 included patients who received more than 2 ablation procedures. Baseline characteristics, medications, serum biochemistry, echocardiographic results, AF types, AF durations, triggers, and procedural durations at the index procedure were investigated to determine their impact on the necessity of multiple procedures.
Electrophysiological Study and Stepwise Ablation Procedure The details have been described in our previous work.2,12-18 In brief, after providing written informed consent, each patient underwent an electrophysiological study and catheter ablation while in the fasting nonsedated state. All antiarrhythmic drugs except for amiodarone were withdrawn for at least 5 half-lives before the electrophysiological study and ablation procedure. Local anesthesia was used for all ablation procedures. All patients received the stepwise catheter ablation procedure for AF. The stepwise procedure of the catheter ablation of AF involved the following steps:12-17 Step 1 (isolation of the pulmonary veins): In the patients presenting to the lab in sinus rhythm, we did try to induce AF with burst atrial pacing or medication. We first tried to find the spontaneous onset of the ectopy triggering the AF during the baseline or after an infusion of isoproterenol (up to 4 µg/min). If spontaneous AF did not appear, short duration burst pacing from the right atrium, coronary sinus, and PVs was used to facilitate spontaneous AF under isoproterenol infusion. If AF could not be induced, high current burst pacing from the right atrium and coronary sinus or administration of high-dose adenosine (18–24 mg) was performed to induce AF. PV triggers were considered when burst electrical activity was observed inside the PVs from the circular catheter recordings or intermittent PV tachycardia observed with faster tachycardia cycle length inside the PVs when compared to that of the rest of the atrium or coronary sinus (CS) recordings.18 After a successful transseptal procedure, continuous circumferential lesions were created encircling the right and left PV ostia guided by the NavX system using an irrigated 4.0-mm tipped ablation catheter (Chilli II, EPT, Boston Scientific Corporation, Natick, MA, USA or CoolPath, St. Jude Medical). Radiofrequency (RF) energy was applied continuously while repositioning the catheter tip every 40 seconds with a target temperature of 35–40 °C and maximum power of 25–30 W. Supplementary ablation applications were applied along the circumferential lines close to the earliest ipsilateral PV potentials. Furthermore, ablation of the residual PV potentials was performed from the atrial side of the PV antrum using the electrogram-guided approach to obtain entrance block. Successful circumferential PV isolation was demonstrated by the absence of any
Characteristics of Multiple AF Ablation Procedures
1049
electrical activity inside the PV or dissociated PV activity during AF. Step 2 (linear ablation): If AF did not stop after the first step, additional linear ablation was performed at both the anterior roof and lateral mitral isthmus with an irrigated 4.0-mm tipped ablation catheter (Chilli II, EPT, Boston Scientific Corporation or CoolPath, St. Jude Medical). RF energy was applied continuously while repositioning the catheter tip every 40 seconds with a target temperature of 35–40 °C and maximum power of 25–30 W. Ablation was guided by the NavX system with the creation of split potentials or an electrogram voltage reduction of >50% after each application of radiofrequency energy. An RA cavotricuspid isthmus ablation was performed with an 8 mm-tip EPT ablation catheter (Boston Scientific Corporation) with a maximum power of 70 W, temperature of 70 °C, and duration of 120 seconds. Bi-directional conduction block of the cavotricuspid isthmus was confirmed after restoration to sinus rhythm. Step 3 (defragmentation): In the patients with nonparoxysmal AF, if AF did not stop after steps 1–2 of the ablation procedure, an additional complex fractionated atrial electrogram (CFAE) ablation was performed sequentially based on the results of the CFAE maps after the circumferential PV isolation. The CFAE ablation was confined to the maximal CFAEs (Fractionation interval, FI < 50 milliseconds) in the left and right atrium.14,15 The endpoint of the CFAE ablation was to obtain a prolongation of the cycle length, eliminate the CFAEs (thus, an FI >120 milliseconds), or abolish the local fractionated potentials (bipolar voltage
Predictors and Characteristics of Multiple (More Than 2) Catheter Ablation Procedures for Atrial Fibrillation LI-WEI LO, M.D.,∗ ,† YENN-JIANG LIN, M.D.,∗ ,† SHIH-LIN CHANG, M.D.,∗ ,† YU-FENG HU, M.D.,∗ ,† TZE-FAN CHAO, M.D.,∗ ,† FA-PO CHUNG, M.D.,∗ ,† JO-NAN LIAO, M.D.,∗ ,† CHEUN-WANG CHIOU, M.D.,∗ ,† HSUAN-MING TSAO, M.D.,†,‡ and SHIH-ANN CHEN, M.D.∗ ,† From the ∗ Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; †Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan; and ‡National Yang-Ming University Hospital, Ilan, Taiwan
Characteristics of Multiple AF Ablation Procedures. Background: The recurrence of atrial fibrillation (AF) is not uncommon in the era of catheter ablation. This study aimed to evaluate the characteristics of AF patients who underwent multiple (>2) ablation procedures. Methods and Results: Of 666 consecutive patients (53 ± 11 y/o, 484 men) who underwent catheter ablation of AF (paroxysmal AF, n = 530), 144 (22%) underwent 2 procedures and 52 (8%) underwent more than 2 procedures due to symptomatic recurrences refractory to medication during 48 ± 23 months of follow-up. Baseline and procedural characteristics at the index procedure were investigated to determine their impact on the necessity of multiple procedures. After 2 procedures, 48 (92%) of 52 patients had pulmonary vein (PV) ectopic beats initiating AF. Coexisting PV and non-PV triggers were found in 23 of 48 patients. In a multivariate analysis, the presence of non-PV triggers (P = 0.004; odds ratio 2.69, 95% CI 1.37–5.28) at the index procedure was the only independent predictor of necessary multiple procedures. Among patients with non-PV ectopic beats initiating AF at the index procedure, the presence of ligament of Marshall triggers (P = 0.001, odds ratio 6.74, 95% CI 2.13–21.32) could predict the necessity of multiple procedures. Conclusions: The need for multiple catheter ablation procedures can be predicted by the presence of non-PV ectopic beats initiating AF at the index procedure. However, PV-initiated AF remains the major cause of AF recurrence despite multiple catheter ablation procedures. (J Cardiovasc Electrophysiol, Vol. 26, pp. 1048-1056, October 2015) atrial fibrillation, catheter ablation, nonpulmonary vein ectopy, pulmonary vein isolation, recurrence Introduction A decade ago, catheter ablation of atrial fibrillation (AF) was introduced as a method of maintaining sinus rhythm.1,2 The past 10 years of AF ablation have been characterized by a better understanding of the mechanisms of AF and by the evolution of new concepts associated with technological innovations. The updated worldwide survey of catheter ablation for AF reported that catheter ablation is effective in approximately 80% of patients after 1.3 procedures.3 Recently, long-term follow-up results after catheter ablation have been reported, and the single procedure results are not satisfactory. Ouyang et al. reported that in the majority of paroxysmal AF patients with normal left ventricular function, The present work was supported by the Taipei Veterans General Hospital (V101B-010, V102B-002, V102E7-003, V103C-042, V103C-126, V103E7-002, VGHUST103-G1-3-1), Ministry of Science and Technology (NSC100-2314-B-075-054-MY3, NSC 101-2911-I-008-001, NSC1022325-B-010-005, MOST 103-2314-B-075-062-MY3), and Research Foundation of Cardiovascular Medicine (RFCM 100-02-011, 101-01-001).
only 47% remained in stable sinus rhythm 4.8 years after circumferential pulmonary vein (PV) isolation.4 The Bordeaux group reported that the AF-free survival rate after a single ablation procedure was only 29% after 5 years.5 Similarly, studies from the Taipei and Hamburg groups reported longterm recurrence-free rates lower than 30% in nonparoxysmal AF patients after a single ablation procedure.6,7 Patients with AF originating from non-PV ectopy have worse outcomes than patients with PV ectopy alone.8 A portion of patients require multiple procedures. It has been reported that PV connections are the major cause of AF recurrences despite multiple (>2) ablation procedures. Repeat PV isolation can effectively eliminate the AF with a satisfactory outcome.9 Recently, a study from Lin et al. also reported the importance of repeat PV isolation and non-PV triggers during recurrence after multiple repeat procedures.10 However, predictors in patients who require multiple ablation procedures have not been previously clarified. Thus, the aim of this study was to evaluate characteristics and predictors in AF patients who received multiple (>2) ablation procedures.
Disclosures: None. Address for correspondence: Shih-Ann Chen, M.D., Division of Cardiology, Taipei Veterans General Hospital, 201, Sec. 2, Shih-Pai Road, Taipei, Taiwan. Fax: 886-2-2873-5656; E-mail: [email protected] Manuscript received 21 April 2015; Revised manuscript received 13 June 2015; Accepted for publication 17 June 2015. doi: 10.1111/jce.12748
Methods Patient Population Of 666 consecutive AF patients (paroxysmal/nonparo xysmal 530/136) who underwent catheter ablation, 144 (22%) received 2 procedures and 52 (8%) received more than 2 procedures due to symptomatic recurrences refractory to medication. During the index and repeat
Lo et al.
procedures, the same mapping (electroanatomical mapping using NavX, St. Jude Medical, St. Paul, MN, USA) and ablation techniques were used in all patients. Paroxysmal AF was defined as AF of less than 7 days’ duration while chronic AF included patients with persistent (sustained beyond 7 days) and long-lasting persistent (continuous AF for more than 1 year) AF.11 The study protocol was reviewed and approved by the hospital’s institutional review board. Patients were divided into 2 groups: group 1 comprised patients who received 1 or 2 procedures and group 2 included patients who received more than 2 ablation procedures. Baseline characteristics, medications, serum biochemistry, echocardiographic results, AF types, AF durations, triggers, and procedural durations at the index procedure were investigated to determine their impact on the necessity of multiple procedures.
Electrophysiological Study and Stepwise Ablation Procedure The details have been described in our previous work.2,12-18 In brief, after providing written informed consent, each patient underwent an electrophysiological study and catheter ablation while in the fasting nonsedated state. All antiarrhythmic drugs except for amiodarone were withdrawn for at least 5 half-lives before the electrophysiological study and ablation procedure. Local anesthesia was used for all ablation procedures. All patients received the stepwise catheter ablation procedure for AF. The stepwise procedure of the catheter ablation of AF involved the following steps:12-17 Step 1 (isolation of the pulmonary veins): In the patients presenting to the lab in sinus rhythm, we did try to induce AF with burst atrial pacing or medication. We first tried to find the spontaneous onset of the ectopy triggering the AF during the baseline or after an infusion of isoproterenol (up to 4 µg/min). If spontaneous AF did not appear, short duration burst pacing from the right atrium, coronary sinus, and PVs was used to facilitate spontaneous AF under isoproterenol infusion. If AF could not be induced, high current burst pacing from the right atrium and coronary sinus or administration of high-dose adenosine (18–24 mg) was performed to induce AF. PV triggers were considered when burst electrical activity was observed inside the PVs from the circular catheter recordings or intermittent PV tachycardia observed with faster tachycardia cycle length inside the PVs when compared to that of the rest of the atrium or coronary sinus (CS) recordings.18 After a successful transseptal procedure, continuous circumferential lesions were created encircling the right and left PV ostia guided by the NavX system using an irrigated 4.0-mm tipped ablation catheter (Chilli II, EPT, Boston Scientific Corporation, Natick, MA, USA or CoolPath, St. Jude Medical). Radiofrequency (RF) energy was applied continuously while repositioning the catheter tip every 40 seconds with a target temperature of 35–40 °C and maximum power of 25–30 W. Supplementary ablation applications were applied along the circumferential lines close to the earliest ipsilateral PV potentials. Furthermore, ablation of the residual PV potentials was performed from the atrial side of the PV antrum using the electrogram-guided approach to obtain entrance block. Successful circumferential PV isolation was demonstrated by the absence of any
Characteristics of Multiple AF Ablation Procedures
1049
electrical activity inside the PV or dissociated PV activity during AF. Step 2 (linear ablation): If AF did not stop after the first step, additional linear ablation was performed at both the anterior roof and lateral mitral isthmus with an irrigated 4.0-mm tipped ablation catheter (Chilli II, EPT, Boston Scientific Corporation or CoolPath, St. Jude Medical). RF energy was applied continuously while repositioning the catheter tip every 40 seconds with a target temperature of 35–40 °C and maximum power of 25–30 W. Ablation was guided by the NavX system with the creation of split potentials or an electrogram voltage reduction of >50% after each application of radiofrequency energy. An RA cavotricuspid isthmus ablation was performed with an 8 mm-tip EPT ablation catheter (Boston Scientific Corporation) with a maximum power of 70 W, temperature of 70 °C, and duration of 120 seconds. Bi-directional conduction block of the cavotricuspid isthmus was confirmed after restoration to sinus rhythm. Step 3 (defragmentation): In the patients with nonparoxysmal AF, if AF did not stop after steps 1–2 of the ablation procedure, an additional complex fractionated atrial electrogram (CFAE) ablation was performed sequentially based on the results of the CFAE maps after the circumferential PV isolation. The CFAE ablation was confined to the maximal CFAEs (Fractionation interval, FI < 50 milliseconds) in the left and right atrium.14,15 The endpoint of the CFAE ablation was to obtain a prolongation of the cycle length, eliminate the CFAEs (thus, an FI >120 milliseconds), or abolish the local fractionated potentials (bipolar voltage
