Comparison of Different Approaches to Atrioventricular Junction Ablation and Pacemaker Implantation in Patients with Atrial Fibrillation NISHA ARENJA, M.D., SVEN KNECHT, PH.D., BEAT SCHAER, M.D., TOBIAS REICHLIN, M.D., NIKOLA PAVLOVIC, M.D., STEFAN OSSWALD, M.D., ¨ CHRISTIAN STICHERLING, M.D., and MICHAEL KUHNE, M.D. From the Department of Cardiology/Electrophysiology, University Hospital Basel, Basel, Switzerland
Background: To compare the feasibility and efficiency of atrioventricular junction (AVJ) ablation and device implantation in patients with drug-refractory atrial fibrillation using three different approaches. Methods: Sixty-nine patients (57% male; age 72 ± 10; ejection fraction 45 ± 15%) undergoing device implantation and AVJ ablation were retrospectively studied at a tertiary referral center. In 20 patients (29%) AVJ ablation was performed via the femoral vein immediately following device implantation (group 1), whereas 33 patients (48%) underwent a staged procedure with AVJ ablation via the femoral vein >3 weeks after device implantation (group 2). In a third group of 16 patients (23%), AVJ ablation was performed during device implantation through the pocket using the same axillary vein access site (group 3). The main outcome measures were: procedure time, fluoroscopy time, laboratory occupancy time, and success rate. Results: There was a significant difference in procedure time (118 ± 45 minutes. in group 1, 133 ± 32 minutes in group 2, and 87 ± 26 minutes in group 3, P < 0.001) and the laboratory occupancy time (175 ± 48 minutes in group 1, 200 ± 32 minutes in group 2, and 121 ± 27 minutes in group 3, P < 0.001). There was no difference in fluoroscopy time (group 1: 20 ± 15 minutes, group 2: 27 ± 22 minutes, and group 3: 24 ± 9 minutes P = 0.4). The procedure was successfully completed in all patients, but cross-over to a femoral approach was required in one patient in group 3. Conclusion: The alternative approach of AVJ ablation during permanent pacemaker implantation from the same axillary vein access site is feasible and more efficient compared to the femoral approach. (PACE 2014; 37:1686–1693) atrial fibrillation, atrioventricular junction ablation, pacemaker implantation, alternative approach, axillary vein access site
Financial disclosures: Nisha Arenja, Sven Knecht, and Tobias Reichlin: none. Michael Kuhne has served on the speakers’ ¨ bureau for Boston Scientific, St. Jude Medical, and Biotronik and serves as a proctor for Medtronic. He has received lecture/consulting fees from Sorin, Boehringer Ingelheim, Bayer, Sanofi Aventis, Novartis, and MSD. He has received unrestricted grants from Sanofi Aventis, Bayer, and Boehringer Ingelheim. Beat Schaer has served on the speakers’ bureau for Medtronic and Sorin. Stefan Osswald has served on the speakers’ bureau for Medtronic, Boston Scientific, Biotronik, St. Jude Medical, Sanofi Aventis, and Astra Zeneca and has received unrestricted grants from Medtronic, Boston Scientific, Biotronik, St. Jude Medical, Sanofi Aventis, and Astra Zeneca. Christian Sticherling has served on the speakers’ bureau for Medtronic, Biotronik, Boston Scientific, Sorin, and Sanofi Aventis, has received study grants from Boston Scientific and Biotronik and has received consulting fees from Sanofi Aventis and Medtronic. Address for reprints: Michael Kuhne, M.D., Department ¨ of Cardiology/Electrophysiology, University Hospital Basel, Petersgraben 4 CH- 4031 Basel, Switzerland. Fax: 41 61 265 45 98; e-mail: [email protected] Received April 9, 2014; revised June 3, 2014; accepted June 17, 2014. doi: 10.1111/pace.12481
Introduction Atrial fibrillation (AF) is the most common arrhythmia with a prevalence of 1–2% in the general population and up to 10% in elderly subjects.1 Persistent or permanent AF with rapid ventricular response may lead to worsening of left ventricular (LV) function.2,3 Atrioventricular junction (AVJ) ablation in combination with permanent pacemaker (PM) implantation has been used as a method of rate control for patients with AF for over 25 years.4,5 It is a valid therapeutic option for patients with symptomatic, drug-refractory AF.6–8 The procedure is simple, may alleviate symptoms, and improves LV systolic function.9 After PM implantation, complete heart block is achieved by performing percutaneous radiofrequency (RF) catheter ablation at the level of the AV node. This can be achieved by different approaches. A frequently used approach to AVJ ablation involves vascular access for the ablation catheter via the femoral vein immediately following PM implantation, but some operators prefer AVJ ablation followed by pacemaker insertion.10 Another strategy is to perform a staged procedure
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with PM implantation several weeks after AVJ ablation via the femoral vein. This approach may be considered the safest because AV nodal conduction is still intact during the early phase after PM implantation when the risk of acute lead dislodgement is the highest. Alternatively, AVJ ablation can be performed during PM implantation through the pocket using the same axillary vein access site. This procedure has the advantage that it can be performed in the same session, from the same site, and by the same operator, which can potentially shorten total procedure time. The reduction of total electrophysiology (EP) laboratory occupancy time may have a positive impact on costs. The purpose of this study was therefore to compare the feasibility and efficiency of AVJ ablation using three different approaches. Methods Setting and Study Population This retrospective study used data from a series of consecutive patients with symptomatic, drug-refractory AF referred to the University Hospital Basel, Switzerland, for device implantation and AVJ ablation. The series consisted of 69 consecutive patients who underwent singleor dual-chamber PM, implantable cardioverter defibrillator (ICD), or cardiac resynchronization therapy (CRT) device implantation and AVJ ablation. In 20 patients (29%), AVJ ablation was performed via the femoral vein immediately after device implantation (group 1). Thirty-three patients (48%) underwent a staged procedure with AVJ ablation via the femoral vein >3 weeks after device implantation (group 2). In a third group of 16 patients (23%), AVJ ablation was performed during PM implantation through the pocket using the same axillary vein access site (group 3). Device Implantation Device implantation was performed in a dedicated EP laboratory. We used a standard technique with vascular access via the axillary vein under local anesthesia. In patients with permanent AF, a single-chamber rate-responsive pacemaker (VVIR) was implanted whereas a dual-chamber pacemaker (DDDR) was implanted in patients with paroxysmal AF. The right ventricular lead was commonly implanted in an apical position, but septal lead placement could be performed at the discretion of the operator. Both active and passive fixation leads were used. Additionally, in patients with reduced LV ejection fraction, an ICD or CRT device was implanted based on the current guidelines. The generator was placed subcutaneously in the left infraclavicular
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region. Oral anticoagulation was not interrupted for device implantation or AVJ ablation. AV Junction Ablation Group 1: Femoral Approach
After implantation, the device was interrogated and appropriate values for sensing, pacing, and impedance were documented before proceeding with AV junction ablation. The device was programmed to VOO with a lower rate limit of 30 beats/min. During that time, the right groin was prepped and draped in the usual fashion. Ablation of the AV junction was performed using a standard technique as described before.11,12 Briefly, the right femoral vein was punctured using the Seldinger technique and an 8-French introducer sheath was inserted. RF catheter ablation was performed using a 4-mm-tip catheter. The catheter was advanced across the tricuspid valve annulus under fluoroscopic guidance (using the right anterior and left anterior oblique view (Figs. 1 A and B). The catheter was withdrawn with a septal torque until a large His signal was found and then withdrawn further until atrial signals could clearly be identified.13 The endpoint of ablation was complete atrioventricular (AV) block. After ablation and documentation of complete AV block, a minimal interval of 15 minutes was used as a waiting period. Proper device function was ensured, and the device was programmed to a lower rate limit of 90 beats/min for 24 hours and then to 80 beats/min for 6 weeks. After 6 weeks, the lower rate limit was set to 60 beats/min in the VVIR mode (or DDDR mode with mode switch activated). Group 2: Staged Femoral Approach
The second group of patients underwent the same procedure as described above, but AVJ ablation was performed during a second procedure more than 3 weeks after device implantation. As in group 1, a minimal interval of 15 minutes after ablation was used as a waiting period. Group 3: Axillary Vein Approach
When using a single-chamber device (VVIR pacemaker or ICD), the axillary vein was punctured twice. A peel-away introducer sheath was inserted over the guidewire, and the ventricular lead was positioned at the right ventricular apex or septum under fluoroscopic guidance. Once satisfactory sensing and pacing thresholds and impedance values were obtained, the lead was tied down at its entry to the vein and connected to the pulse generator. The device was programmed to a VOO mode at a rate of 30 beats/min. An introducer sheath was then advanced over the
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Figure 1. Top: Right anterior (Panel A) and left anterior (Panel B) oblique view in a patient undergoing AV junction ablation using the femoral approach 4 weeks after device implantation. Note the relatively direct (horizontal) approach to the His region with the inferior approach. Bottom: Right anterior (Panel C) and left anterior (Panel D) oblique view in a patient undergoing AV junction ablation using the axillary vein approach during implantation of a biventricular pacemaker. Note the infero-superior orientation of the distal part of the ablation catheter with the superior approach. AV = atrioventricular.
second guidewire and a large curve 4-mm-tip ablation catheter was positioned near the His bundle region. An anteroseptal position on the tricuspid annulus was reached by deflection of the tip superiorly to form a “J-shape” and then advancing the catheter with septal torque (Figs. 1 C and D). The goal was to find a His potential at a site where atrial signals could also clearly be identified. After successful AVJ ablation, the ablation catheter was withdrawn, the 8-French sheath was removed, and hemostasis was achieved by applying local pressure. In patients who required an atrial lead, a peel-away sheath was used and the atrial lead was implanted through this sheath after retracting the ablation catheter. In patients who received CRT, the LV lead was implanted after placing the right ventricular lead, but before AVJ ablation. The time required for
1688
additional lead implant (if necessary) and pocket closure was counted as a waiting period after documentation of complete AV block. Main Outcome Measures The primary outcome measures of this study were total net procedure time (“skin to skin”: defined as the actual time the operator required to complete both device implantation and AVJ ablation), total fluoroscopy time (for both procedures), total EP laboratory occupancy time (time the patient spent in the EP laboratory), the acute success rate of the three approaches, and the permanency of AV block 3 months after AVJ ablation. Secondary outcome measures were net RF ablation duration, periprocedural complications (e.g., pneumothorax, tamponade), and
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procedure-related complications (e.g., groin hematoma, pocket hematoma, lead dislodgement, infection). Statistical Analysis Continuous variables are described as the mean ± standard deviation (SD) for the normally distributed and as median for the nonnormally distributed variables. Comparisons were made using the unpaired t-test for normally distributed continuous variables and the Mann-Whitney U test for nonnormally distributed continuous variables. Fisher’s exact test for categorical variables with any field including less than six patients, and χ 2 test for the other categorical variables. Statistical difference between the three AVJ ablation groups was performed by one-way analysis of variance (one-way ANOVA) and post hoc Tukey’s test. A P-value < 0.05 was considered statistically significant. The statistical analyses were performed using the SPSS/PC (version 20.0, IBM Corp., Armonk, NY, USA) software package. Results Baseline Characteristics The mean age of all patients was 72 ± 10 years and 39 of 69 patients (57%) were men. The baseline characteristics of the patients and the three treatment groups are depicted in Table I. With the exception of body mass index, there were no significant differences between the three groups. Forty-five of 69 patients (65%) underwent single or DDDR implantation, whereas CRT-pacemaker and CRT-ICD implantation was performed in 14 (21%) and 10 (15%) patients, respectively. Primary Outcome Measures The procedure of device implantation and AVJ ablation was successful in 20 of 20 (100%) in the femoral group, in 33 of 33 (100%) in the staged femoral group, and 15 of 16 patients (94%) in the axillary vein approach group. In one patient, presumably due to the presence of severely dilated atria, the true His bundle region could not be reached with the superior approach despite the use of a large curve RF ablation catheter. Ablation was attempted, but unsuccessful despite delivering RF energy for >10 minutes. The procedure was successfully completed after crossing over to a conventional femoral approach in this case. The data of this patient were included in the analysis of the axillary vein approach group (group 3). Comparison of the total net procedure time between the three groups demonstrates that the shortest time was achieved with the axillary vein
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approach in group 3 (118 ± 45 minutes in group 1, 133 ± 32 minutes in group 2, and 87 ± 26 minutes in group 3, respectively P < 0.001). The shortest total EP laboratory occupancy time was also seen with the axillary vein approach in group 3 (175 ± 48 minutes in group 1, 200 ± 32 minutes in group 2, and 121 ± 27 minutes in group 3, respectively P < 0.001). However, the total fluoroscopy time was not different between the three groups (group 1: 20 ± 15 minutes, group 2: 27 ± 22 minutes, and group 3: 24 ± 9 minutes; P = 0.4, Table II). All patients in the femoral approach and axillary approach groups had permanent complete AV block 3 months after AVJ ablation. In two of 33 patients (6%) in the staged femoral approach group, recovery of AV conduction with recurrence of symptomatic AF occurred one and 81 days after AVJ ablation, respectively. In the latter case, persistent mechanical interruption of AV conduction had occurred during the index attempt of AVJ ablation, and ablation had then been performed with the RF ablation catheter at that site. Repeat AVJ ablation resulted in permanent AV block in both patients. Secondary Outcome Measures The median net RF ablation time to achieve complete AV block was 300 (interquartile range [IQR] 122; 542) seconds and there was no difference between the three groups. There were no periprocedural complications. No lead dislodgements during or after ablation occurred in this patient series. In particular, the axillary approach did not result in acute lead dislodgement in any case. Cardiac tamponade, pocket hematoma, pneumothorax, infection, or thromboembolism were not observed in any patient. Only one procedure-related complication (groin hematoma) was observed in one of 20 patients (5%) in the femoral approach group. Discussion Main Findings To our knowledge, this is the first study reporting the feasibility and efficiency of AVJ ablation and device implantation through the pocket using the same axillary vein access site. The main findings of this study are the alternative strategy of AVJ ablation and device implantation using a vascular access site via the axillary vein is feasible and safe with acute success in 94% of patients (and 100% of patients after cross-over to a standard femoral approach to AVJ ablation in one patient) and no procedure-related complications. Ablation of the AVJ with the axillary approach
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Table I. Baseline Characteristics
Age, mean ± SD Male, n (%) BMI (kg/m2 ), mean ± SD History, n (%) Hypertension Diabetes mellitus Dyslipidemia NYHA Class NYHA 2 NYHA 3 NYHA 4 Medication, n (%) Aspirin Vitamin K antagonists β-Blockers ACE inhibitors /AT-2receptor blockers Calcium channel blockers Diuretics Digoxin Antiarrhythmic drugs Left Atrial Dilatation, n (%) LV Ejection Fraction, mean ± SD Underlying Rhythm, n (%) Paroxysmal AF Permanent AF
All (n = 69)
Group 1: Femoral Approach (n = 20)
Group 2: Staged Femoral (n = 33)
Group 3: Axillary Approach (n = 16)
P Value (between the Three Groups)
72 ± 10 39 (57) 27 ± 4
71 ± 12 11 (55) 28 ± 5
73 ± 8 20 (61) 25 ± 3
72 ± 10 8 (50) 28 ± 5
0.6 0.8 0.01
53 (77) 11 (16)
16 (80) 5 (25)
25 (76) 5 (15)
12 (75) 1 (6)
0.9 0.3
28 (41)
9 (45)
14 (42)
5 (31)
0.7 0.1
35 (51) 30 (44) 4 (6)
12 (60) 7 (35) 1 (5)
19 (58) 11 (33) 3 (9)
4 (25) 12 (75) 0 (0)
12 (17) 62 (90)
2 (10) 19 (95)
7 (21) 30 (91)
3 (19) 13 (81)
0.6 0.4
62 (90) 48 (70)
17 (85) 15 (75)
31 (94) 21 (64)
14 (88) 12 (75)
0.5 0.6
7 (10)
2 (10)
3 (9)
2 (13)
0.9
49 (71) 14 (20) 26 (38)
14 (70) 6 (30) 5 (25)
24 (73) 4 (12) 14 (42)
11 (69) 4 (25) 7 (44)
0.9 0.3 0.4
54 (78)
17 (85)
26 (79)
11 (69)
0.5
45 ± 15
47 ± 14
45 ± 16
42 ± 16
0.7
15 (22)
3 (15)
9 (27)
3 (19)
0.3
54 (78)
17 (85)
24 (73)
13 (81)
0.9
ACE = angiotensin-converting enzyme; AF = atrial fibrillation; BMI = body mass index; LV = left ventricular; NYHA = New York Heart Association; SD = standard deviation.
“through the pocket” is not more complicated or time-consuming than the standard method via the femoral vein. In contrast, the procedure time and the total EP laboratory occupancy times
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were shorter with the axillary vein approach to AVJ ablation. Of note, net RF ablation duration and total fluoroscopy time did not increase with the use of the axillary vein approach. Finally,
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Table II. Procedure Data
All All Devices, n Net procedure time (minutes) Total electrophysiology laboratory time (minutes) Total fluoroscopy time (minutes) Total RF ablation time (seconds)—median (IQR) VVIR-PM, n (%) Net procedure time (minutes) Total electrophysiology laboratory time (minutes) Total fluoroscopy time (minutes) DDDR-PM, n (%) Net procedure time (minutes) Total electrophysiology laboratory time (minutes) Total fluoroscopy time (minutes) CRT-PM/CRT-ICD, n (%) Net procedure time (minutes) Total electrophysiology laboratory time (minutes) Total fluoroscopy time (minutes)
Group 1: Femoral Approach
Group 2: Staged Femoral
Group 3: Axillary Approach
P Value (between the Three Groups)
69 118 ± 39
20 118 ± 45
33 133 ± 32
16 87 ± 26
Background: To compare the feasibility and efficiency of atrioventricular junction (AVJ) ablation and device implantation in patients with drug-refractory atrial fibrillation using three different approaches. Methods: Sixty-nine patients (57% male; age 72 ± 10; ejection fraction 45 ± 15%) undergoing device implantation and AVJ ablation were retrospectively studied at a tertiary referral center. In 20 patients (29%) AVJ ablation was performed via the femoral vein immediately following device implantation (group 1), whereas 33 patients (48%) underwent a staged procedure with AVJ ablation via the femoral vein >3 weeks after device implantation (group 2). In a third group of 16 patients (23%), AVJ ablation was performed during device implantation through the pocket using the same axillary vein access site (group 3). The main outcome measures were: procedure time, fluoroscopy time, laboratory occupancy time, and success rate. Results: There was a significant difference in procedure time (118 ± 45 minutes. in group 1, 133 ± 32 minutes in group 2, and 87 ± 26 minutes in group 3, P < 0.001) and the laboratory occupancy time (175 ± 48 minutes in group 1, 200 ± 32 minutes in group 2, and 121 ± 27 minutes in group 3, P < 0.001). There was no difference in fluoroscopy time (group 1: 20 ± 15 minutes, group 2: 27 ± 22 minutes, and group 3: 24 ± 9 minutes P = 0.4). The procedure was successfully completed in all patients, but cross-over to a femoral approach was required in one patient in group 3. Conclusion: The alternative approach of AVJ ablation during permanent pacemaker implantation from the same axillary vein access site is feasible and more efficient compared to the femoral approach. (PACE 2014; 37:1686–1693) atrial fibrillation, atrioventricular junction ablation, pacemaker implantation, alternative approach, axillary vein access site
Financial disclosures: Nisha Arenja, Sven Knecht, and Tobias Reichlin: none. Michael Kuhne has served on the speakers’ ¨ bureau for Boston Scientific, St. Jude Medical, and Biotronik and serves as a proctor for Medtronic. He has received lecture/consulting fees from Sorin, Boehringer Ingelheim, Bayer, Sanofi Aventis, Novartis, and MSD. He has received unrestricted grants from Sanofi Aventis, Bayer, and Boehringer Ingelheim. Beat Schaer has served on the speakers’ bureau for Medtronic and Sorin. Stefan Osswald has served on the speakers’ bureau for Medtronic, Boston Scientific, Biotronik, St. Jude Medical, Sanofi Aventis, and Astra Zeneca and has received unrestricted grants from Medtronic, Boston Scientific, Biotronik, St. Jude Medical, Sanofi Aventis, and Astra Zeneca. Christian Sticherling has served on the speakers’ bureau for Medtronic, Biotronik, Boston Scientific, Sorin, and Sanofi Aventis, has received study grants from Boston Scientific and Biotronik and has received consulting fees from Sanofi Aventis and Medtronic. Address for reprints: Michael Kuhne, M.D., Department ¨ of Cardiology/Electrophysiology, University Hospital Basel, Petersgraben 4 CH- 4031 Basel, Switzerland. Fax: 41 61 265 45 98; e-mail: [email protected] Received April 9, 2014; revised June 3, 2014; accepted June 17, 2014. doi: 10.1111/pace.12481
Introduction Atrial fibrillation (AF) is the most common arrhythmia with a prevalence of 1–2% in the general population and up to 10% in elderly subjects.1 Persistent or permanent AF with rapid ventricular response may lead to worsening of left ventricular (LV) function.2,3 Atrioventricular junction (AVJ) ablation in combination with permanent pacemaker (PM) implantation has been used as a method of rate control for patients with AF for over 25 years.4,5 It is a valid therapeutic option for patients with symptomatic, drug-refractory AF.6–8 The procedure is simple, may alleviate symptoms, and improves LV systolic function.9 After PM implantation, complete heart block is achieved by performing percutaneous radiofrequency (RF) catheter ablation at the level of the AV node. This can be achieved by different approaches. A frequently used approach to AVJ ablation involves vascular access for the ablation catheter via the femoral vein immediately following PM implantation, but some operators prefer AVJ ablation followed by pacemaker insertion.10 Another strategy is to perform a staged procedure
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with PM implantation several weeks after AVJ ablation via the femoral vein. This approach may be considered the safest because AV nodal conduction is still intact during the early phase after PM implantation when the risk of acute lead dislodgement is the highest. Alternatively, AVJ ablation can be performed during PM implantation through the pocket using the same axillary vein access site. This procedure has the advantage that it can be performed in the same session, from the same site, and by the same operator, which can potentially shorten total procedure time. The reduction of total electrophysiology (EP) laboratory occupancy time may have a positive impact on costs. The purpose of this study was therefore to compare the feasibility and efficiency of AVJ ablation using three different approaches. Methods Setting and Study Population This retrospective study used data from a series of consecutive patients with symptomatic, drug-refractory AF referred to the University Hospital Basel, Switzerland, for device implantation and AVJ ablation. The series consisted of 69 consecutive patients who underwent singleor dual-chamber PM, implantable cardioverter defibrillator (ICD), or cardiac resynchronization therapy (CRT) device implantation and AVJ ablation. In 20 patients (29%), AVJ ablation was performed via the femoral vein immediately after device implantation (group 1). Thirty-three patients (48%) underwent a staged procedure with AVJ ablation via the femoral vein >3 weeks after device implantation (group 2). In a third group of 16 patients (23%), AVJ ablation was performed during PM implantation through the pocket using the same axillary vein access site (group 3). Device Implantation Device implantation was performed in a dedicated EP laboratory. We used a standard technique with vascular access via the axillary vein under local anesthesia. In patients with permanent AF, a single-chamber rate-responsive pacemaker (VVIR) was implanted whereas a dual-chamber pacemaker (DDDR) was implanted in patients with paroxysmal AF. The right ventricular lead was commonly implanted in an apical position, but septal lead placement could be performed at the discretion of the operator. Both active and passive fixation leads were used. Additionally, in patients with reduced LV ejection fraction, an ICD or CRT device was implanted based on the current guidelines. The generator was placed subcutaneously in the left infraclavicular
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region. Oral anticoagulation was not interrupted for device implantation or AVJ ablation. AV Junction Ablation Group 1: Femoral Approach
After implantation, the device was interrogated and appropriate values for sensing, pacing, and impedance were documented before proceeding with AV junction ablation. The device was programmed to VOO with a lower rate limit of 30 beats/min. During that time, the right groin was prepped and draped in the usual fashion. Ablation of the AV junction was performed using a standard technique as described before.11,12 Briefly, the right femoral vein was punctured using the Seldinger technique and an 8-French introducer sheath was inserted. RF catheter ablation was performed using a 4-mm-tip catheter. The catheter was advanced across the tricuspid valve annulus under fluoroscopic guidance (using the right anterior and left anterior oblique view (Figs. 1 A and B). The catheter was withdrawn with a septal torque until a large His signal was found and then withdrawn further until atrial signals could clearly be identified.13 The endpoint of ablation was complete atrioventricular (AV) block. After ablation and documentation of complete AV block, a minimal interval of 15 minutes was used as a waiting period. Proper device function was ensured, and the device was programmed to a lower rate limit of 90 beats/min for 24 hours and then to 80 beats/min for 6 weeks. After 6 weeks, the lower rate limit was set to 60 beats/min in the VVIR mode (or DDDR mode with mode switch activated). Group 2: Staged Femoral Approach
The second group of patients underwent the same procedure as described above, but AVJ ablation was performed during a second procedure more than 3 weeks after device implantation. As in group 1, a minimal interval of 15 minutes after ablation was used as a waiting period. Group 3: Axillary Vein Approach
When using a single-chamber device (VVIR pacemaker or ICD), the axillary vein was punctured twice. A peel-away introducer sheath was inserted over the guidewire, and the ventricular lead was positioned at the right ventricular apex or septum under fluoroscopic guidance. Once satisfactory sensing and pacing thresholds and impedance values were obtained, the lead was tied down at its entry to the vein and connected to the pulse generator. The device was programmed to a VOO mode at a rate of 30 beats/min. An introducer sheath was then advanced over the
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Figure 1. Top: Right anterior (Panel A) and left anterior (Panel B) oblique view in a patient undergoing AV junction ablation using the femoral approach 4 weeks after device implantation. Note the relatively direct (horizontal) approach to the His region with the inferior approach. Bottom: Right anterior (Panel C) and left anterior (Panel D) oblique view in a patient undergoing AV junction ablation using the axillary vein approach during implantation of a biventricular pacemaker. Note the infero-superior orientation of the distal part of the ablation catheter with the superior approach. AV = atrioventricular.
second guidewire and a large curve 4-mm-tip ablation catheter was positioned near the His bundle region. An anteroseptal position on the tricuspid annulus was reached by deflection of the tip superiorly to form a “J-shape” and then advancing the catheter with septal torque (Figs. 1 C and D). The goal was to find a His potential at a site where atrial signals could also clearly be identified. After successful AVJ ablation, the ablation catheter was withdrawn, the 8-French sheath was removed, and hemostasis was achieved by applying local pressure. In patients who required an atrial lead, a peel-away sheath was used and the atrial lead was implanted through this sheath after retracting the ablation catheter. In patients who received CRT, the LV lead was implanted after placing the right ventricular lead, but before AVJ ablation. The time required for
1688
additional lead implant (if necessary) and pocket closure was counted as a waiting period after documentation of complete AV block. Main Outcome Measures The primary outcome measures of this study were total net procedure time (“skin to skin”: defined as the actual time the operator required to complete both device implantation and AVJ ablation), total fluoroscopy time (for both procedures), total EP laboratory occupancy time (time the patient spent in the EP laboratory), the acute success rate of the three approaches, and the permanency of AV block 3 months after AVJ ablation. Secondary outcome measures were net RF ablation duration, periprocedural complications (e.g., pneumothorax, tamponade), and
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procedure-related complications (e.g., groin hematoma, pocket hematoma, lead dislodgement, infection). Statistical Analysis Continuous variables are described as the mean ± standard deviation (SD) for the normally distributed and as median for the nonnormally distributed variables. Comparisons were made using the unpaired t-test for normally distributed continuous variables and the Mann-Whitney U test for nonnormally distributed continuous variables. Fisher’s exact test for categorical variables with any field including less than six patients, and χ 2 test for the other categorical variables. Statistical difference between the three AVJ ablation groups was performed by one-way analysis of variance (one-way ANOVA) and post hoc Tukey’s test. A P-value < 0.05 was considered statistically significant. The statistical analyses were performed using the SPSS/PC (version 20.0, IBM Corp., Armonk, NY, USA) software package. Results Baseline Characteristics The mean age of all patients was 72 ± 10 years and 39 of 69 patients (57%) were men. The baseline characteristics of the patients and the three treatment groups are depicted in Table I. With the exception of body mass index, there were no significant differences between the three groups. Forty-five of 69 patients (65%) underwent single or DDDR implantation, whereas CRT-pacemaker and CRT-ICD implantation was performed in 14 (21%) and 10 (15%) patients, respectively. Primary Outcome Measures The procedure of device implantation and AVJ ablation was successful in 20 of 20 (100%) in the femoral group, in 33 of 33 (100%) in the staged femoral group, and 15 of 16 patients (94%) in the axillary vein approach group. In one patient, presumably due to the presence of severely dilated atria, the true His bundle region could not be reached with the superior approach despite the use of a large curve RF ablation catheter. Ablation was attempted, but unsuccessful despite delivering RF energy for >10 minutes. The procedure was successfully completed after crossing over to a conventional femoral approach in this case. The data of this patient were included in the analysis of the axillary vein approach group (group 3). Comparison of the total net procedure time between the three groups demonstrates that the shortest time was achieved with the axillary vein
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approach in group 3 (118 ± 45 minutes in group 1, 133 ± 32 minutes in group 2, and 87 ± 26 minutes in group 3, respectively P < 0.001). The shortest total EP laboratory occupancy time was also seen with the axillary vein approach in group 3 (175 ± 48 minutes in group 1, 200 ± 32 minutes in group 2, and 121 ± 27 minutes in group 3, respectively P < 0.001). However, the total fluoroscopy time was not different between the three groups (group 1: 20 ± 15 minutes, group 2: 27 ± 22 minutes, and group 3: 24 ± 9 minutes; P = 0.4, Table II). All patients in the femoral approach and axillary approach groups had permanent complete AV block 3 months after AVJ ablation. In two of 33 patients (6%) in the staged femoral approach group, recovery of AV conduction with recurrence of symptomatic AF occurred one and 81 days after AVJ ablation, respectively. In the latter case, persistent mechanical interruption of AV conduction had occurred during the index attempt of AVJ ablation, and ablation had then been performed with the RF ablation catheter at that site. Repeat AVJ ablation resulted in permanent AV block in both patients. Secondary Outcome Measures The median net RF ablation time to achieve complete AV block was 300 (interquartile range [IQR] 122; 542) seconds and there was no difference between the three groups. There were no periprocedural complications. No lead dislodgements during or after ablation occurred in this patient series. In particular, the axillary approach did not result in acute lead dislodgement in any case. Cardiac tamponade, pocket hematoma, pneumothorax, infection, or thromboembolism were not observed in any patient. Only one procedure-related complication (groin hematoma) was observed in one of 20 patients (5%) in the femoral approach group. Discussion Main Findings To our knowledge, this is the first study reporting the feasibility and efficiency of AVJ ablation and device implantation through the pocket using the same axillary vein access site. The main findings of this study are the alternative strategy of AVJ ablation and device implantation using a vascular access site via the axillary vein is feasible and safe with acute success in 94% of patients (and 100% of patients after cross-over to a standard femoral approach to AVJ ablation in one patient) and no procedure-related complications. Ablation of the AVJ with the axillary approach
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Table I. Baseline Characteristics
Age, mean ± SD Male, n (%) BMI (kg/m2 ), mean ± SD History, n (%) Hypertension Diabetes mellitus Dyslipidemia NYHA Class NYHA 2 NYHA 3 NYHA 4 Medication, n (%) Aspirin Vitamin K antagonists β-Blockers ACE inhibitors /AT-2receptor blockers Calcium channel blockers Diuretics Digoxin Antiarrhythmic drugs Left Atrial Dilatation, n (%) LV Ejection Fraction, mean ± SD Underlying Rhythm, n (%) Paroxysmal AF Permanent AF
All (n = 69)
Group 1: Femoral Approach (n = 20)
Group 2: Staged Femoral (n = 33)
Group 3: Axillary Approach (n = 16)
P Value (between the Three Groups)
72 ± 10 39 (57) 27 ± 4
71 ± 12 11 (55) 28 ± 5
73 ± 8 20 (61) 25 ± 3
72 ± 10 8 (50) 28 ± 5
0.6 0.8 0.01
53 (77) 11 (16)
16 (80) 5 (25)
25 (76) 5 (15)
12 (75) 1 (6)
0.9 0.3
28 (41)
9 (45)
14 (42)
5 (31)
0.7 0.1
35 (51) 30 (44) 4 (6)
12 (60) 7 (35) 1 (5)
19 (58) 11 (33) 3 (9)
4 (25) 12 (75) 0 (0)
12 (17) 62 (90)
2 (10) 19 (95)
7 (21) 30 (91)
3 (19) 13 (81)
0.6 0.4
62 (90) 48 (70)
17 (85) 15 (75)
31 (94) 21 (64)
14 (88) 12 (75)
0.5 0.6
7 (10)
2 (10)
3 (9)
2 (13)
0.9
49 (71) 14 (20) 26 (38)
14 (70) 6 (30) 5 (25)
24 (73) 4 (12) 14 (42)
11 (69) 4 (25) 7 (44)
0.9 0.3 0.4
54 (78)
17 (85)
26 (79)
11 (69)
0.5
45 ± 15
47 ± 14
45 ± 16
42 ± 16
0.7
15 (22)
3 (15)
9 (27)
3 (19)
0.3
54 (78)
17 (85)
24 (73)
13 (81)
0.9
ACE = angiotensin-converting enzyme; AF = atrial fibrillation; BMI = body mass index; LV = left ventricular; NYHA = New York Heart Association; SD = standard deviation.
“through the pocket” is not more complicated or time-consuming than the standard method via the femoral vein. In contrast, the procedure time and the total EP laboratory occupancy times
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were shorter with the axillary vein approach to AVJ ablation. Of note, net RF ablation duration and total fluoroscopy time did not increase with the use of the axillary vein approach. Finally,
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DIFFERENT APPROACHES TO AV NODE ABLATION
Table II. Procedure Data
All All Devices, n Net procedure time (minutes) Total electrophysiology laboratory time (minutes) Total fluoroscopy time (minutes) Total RF ablation time (seconds)—median (IQR) VVIR-PM, n (%) Net procedure time (minutes) Total electrophysiology laboratory time (minutes) Total fluoroscopy time (minutes) DDDR-PM, n (%) Net procedure time (minutes) Total electrophysiology laboratory time (minutes) Total fluoroscopy time (minutes) CRT-PM/CRT-ICD, n (%) Net procedure time (minutes) Total electrophysiology laboratory time (minutes) Total fluoroscopy time (minutes)
Group 1: Femoral Approach
Group 2: Staged Femoral
Group 3: Axillary Approach
P Value (between the Three Groups)
69 118 ± 39
20 118 ± 45
33 133 ± 32
16 87 ± 26
