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Catheter ablation of supraventricular tachycardia after tricuspid valve surgery in patients with congenital heart disease: A multicenter comparative study
Catheter ablation of supraventricular tachycardia after tricuspid valve surgery in patients with congenital heart disease: A multicenter comparative study Jeremy P. Moore, MD, MS, FHRS,* Roberto G. Gallotti, MD,* Anca Chiriac, MD, PhD,† Christopher J. McLeod, MBChB, PhD, FHRS,† Elizabeth A. Stephenson, MD, FHRS,‡ Khadijah Maghrabi, MD,x Frank A. Fish, MD,k Orhan U. Kilinc, MD,{ David Bradley, MD, FHRS,{ Ulrich Krause, MD,# Seshadri Balaji, MBBS, PhD,** Kevin M. Shannon, MD* From the *Division of Cardiology, Department of Medicine, UCLA Medical Center, Ahmanson/UCLA Adult Congenital Heart Disease Center, Los Angeles, California, †Department of Cardiovascular Diseases, Mayo Clinic, Jacksonville, Florida, ‡Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, Canada, xDepartment of Pediatrics, King Abdulaziz University, Jeddah, Saudia Arabia, k Division of Pediatric Cardiology, Vanderbilt University Medical Center, Nashville, Tennessee, { Division of Cardiology, CS Mott Children’s Hospital, University of Michigan, Ann Arbor, Michigan, # Division of Pediatric Cardiology, University Hospital, Goettingen, Germany, and **Department of Pediatrics, Division of Pediatric Cardiology, Oregon Health & Science University, Portland, Oregon. BACKGROUND Tricuspid valve (TV) surgery is often required for adult congenital heart disease (ACHD), but may hinder catheter ablation when an artificial material or imbricated tissue covers the tricuspid annulus. OBJECTIVE The purpose of this study was to determine the outcomes of catheter ablation after TV surgery in a large ACHD cohort. METHODS An international retrospective study involving 7 centers was conducted. Patients who did and did not undergo TV surgery were matched for age, lesion classification, and postsurgical duration. TV operations were classified as valve ring/replacement vs repair. RESULTS One hundred thirty-six patients (42 ring/replacement, 39 repair, and 55 no TV surgery; median 32 years [IQR 20 - 46]) underwent 180 procedures targeting 239 tachycardias (cavotricuspid-isthmus dependent intraatrial reentrant tachycardia 36%, other intraatrial reentrant tachycardia 29%, focal atrial tachycardia 18%, and other supraventricular tachyarrhythmia 17%). Post-TV surgery, procedures were longer (4.3 hours vs 3.3 hours; P 5 .003) and required longer fluoroscopy time (31 minutes vs 18 minutes; P 5 .001). At least partial
Introduction Adult patients with congenital heart disease (ACHD) commonly develop atrial arrhythmias that are typically surgical scar-related reentry.1 Cavotricuspid isthmus (CTI)– related atrial flutter is the most commonly identified type of Address reprint requests and correspondence: Dr Jeremy P. Moore, UCLA Medical Center, Ahmanson/UCLA Adult Congenital Heart Disease Center, 100 Medical Plaza Dr Suite 770, Los Angeles, CA 90095. E-mail address: [email protected].
acute success was achieved in 81% of procedures in the TV ring/ replacement group vs 94% in both TV repair and no TV surgery groups (P 5 .03). The difference was driven mainly by ablation of annular substrates, with acute success in 73% of TV ring/replacement, 92% of TV repair, and 94% of no TV surgery groups (P 5 .01). Over a median of 3.0 years, tachycardia recurred after 26% of procedures. TV ring/replacement predicted recurrence in the multivariable analysis (hazard ratio 2.4; 95% confidence interval 1.2–5.2; P 5 .009). CONCLUSION After surgery for ACHD, catheter ablation success was lower and tachycardia recurrence was higher after TV valve ring/replacement surgery. The findings of this retrospective report support future larger multicenter series and prospective evaluation to determine the role of empirical annular substrate ablation. KEYWORDS Catheter ablation; Congenital heart disease; Ebstein’s anomaly; Ring annuloplasty; Tricuspid valve repair; Tricuspid valve replacement (Heart Rhythm 2019;-:1–8) Published by Elsevier Inc. on behalf of Heart Rhythm Society.
arrhythmia,2 yet other atrial arrhythmias can occur that are related to the atriotomy, atrial scar, and damaged tissue. Transection of the CTI using radiofrequency energy is still commonly used despite the type of congenital heart disease, and success rates are generally excellent. Surgical intervention on the tricuspid valve (TV) is often required in ACHD, with reports suggesting that this surgery may complicate subsequent catheter ablation of the CTI.3 There are no comparative data after TV repair,3,4 and there is a distinct paucity of data after TV replacement.
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https://doi.org/10.1016/j.hrthm.2019.07.020
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Figure 1 Illustration of technical difficulty with catheter ablation after tricuspid valve replacement. A portion of the atrial myocardium participating in the reentry circuit may be variably covered by the prosthetic material, hindering attempts to achieve permanent isthmus block.
Conceptually, after TV ring annuloplasty or replacement, a portion of the CTI may become covered by the bioprosthetic material and prevent complete linear ablation of this isthmus (Figure 1).5–9 Despite these considerations, the impact of TV surgery on procedural complexity has not been systematically studied.10–12 In order to clarify the effect of TV surgery on catheter ablation outcomes, a multicenter collaboration involving several experienced ACHD centers was developed. We sought to compare catheter ablation outcomes and procedural techniques for patients with atrial arrhythmias, with and without prior TV surgery.
Methods This was a retrospective study of patients with ACHD undergoing catheter ablation of supraventricular tachyarrhythmia between 2006 and 2018. Centers with experience in ACHD catheter ablation were provided the study protocol in October 2016, after which 7 centers agreed to participate. Data on all TV operations were collected and were recorded as either (1) isolated valve repair, (2) suture annuloplasty with or without valve repair, (3) ring annuloplasty with or without valve repair, or (4) TV replacement. Given the similar consequence of both TV replacement and ring annuloplasty on catheter ablation at the tricuspid annulus, patients undergoing these 2 surgical techniques were combined as 1 group. Similarly, those who underwent either suture annuloplasty or isolated TV repair were combined as 1 group, so ultimately 3 groups were considered for the purpose of the study: (1) TV ring/ replacement, (2) TV repair, and (3) no TV surgery. Patients with and without TV surgery were matched for age, class (biventricular, systemic right ventricular, or single ventricular heart disease), and time elapsed after surgery. Lesion severity was classified according to conventional criteria.13 Annular substrates were defined as those tachycardias that required catheter ablation of myocardium at the TV annulus. These included tricuspid annular focal atrial tachycardias (ATs), right-sided accessory pathways, atrioventricular nodal
reentrant tachycardia, and CTI-dependent intraatrial reentrant tachycardia (CTI-IART). After local ethics committee approval, all centers transmitted clinical data securely to the coordinating center at the University of California, Los Angeles through the Research Electronic Data Capture (REDCap) web application. One of the participating centers reported its own subgroup analysis separately during manuscript preparation, and these patients were included in the present report.14 The clinical variables of interest included patient demographic characteristics, congenital diagnoses, surgical indications, and details of TV surgery including concomitant Maze operation, need for cardiac implantable electronic device (CIED) placement, and administration of antiarrhythmic drug therapy. Catheter ablation details were collected and included the mechanism and location of the targeted arrhythmia for all cases. Particular attention was paid to any unique procedural approaches that were used in order to target tachycardia substrates near the surgically altered TV.
Outcomes Acute complete procedural success was defined as elimination of all stable inducible ATs during catheter ablation. Procedures in which 1 targeted tachycardia was eliminated but inducible tachycardia remained at the end of the procedure were labeled as acute partial success. Procedural complications were noted and specified in detail to the coordinating center for review. After catheter ablation, all patients were typically followed at the participating center at least annually. Symptoms possibly attributable to atrial tachyarrhythmia were evaluated by the treating physician per institutional protocol. Recurrence was defined as any sustained tachyarrhythmia (ie, lasting .30 seconds) demonstrated electrocardiographically or by CIED after an acutely successful catheter ablation procedure. Patients undergoing failed catheter ablation (ie, lack of partial or complete success at the index procedure) were excluded from the recurrence analysis.
Statistical analysis Data are presented as median (interquartile range [IQR]) for continuous variables and as frequency (percentage) for dichotomous variables. For surgical group comparisons, the Wilcoxon rank-sum method was used for continuous variables and the Fisher exact test for categorical variables. To evaluate an association between surgical groups and acute procedural success, the Pearson c2 test was used. For tachycardia recurrence, a Cox proportional hazards model was created that incorporated class of TV surgery as a covariate, with adjustment for additional covariates associated with a P value of ,.1 in the univariable analysis. In order to assess the validity of treating each catheter ablation procedure as an independent event, generalized estimating equation analysis was used in the multivariable analysis. A P value of ,.05 is regarded as significant. Statistical analyses were performed with JMP software version 14.0 and SAS version 9.4 (SAS Institute Inc., Cary, NC).
Moore et al Table 1
Catheter Ablation After Tricuspid Surgery
3
Baseline population characteristics grouped by prior surgical strategy
Patient characteristic
TV ring/replacement (n 5 42)
TV repair (n 5 39)
No TV surgery (n 5 55)
P
Sex: male Age at catheter ablation (y) CHD type Ebstein’s anomaly Tetralogy of Fallot/VSD Single ventricle Systemic RV Other CHD severity Simple Moderate Severe/complex Number of CHD operations Tricuspid valve surgery Surgical indication Regurgitation Stenosis Mixed disease Number of TV operations Valve size (mm) Valve type Mechanical Bioprosthetic Ring annuloplasty Maze operation Antiarrhythmic drugs b-Blocker Amiodarone Digoxin Other* CIED placement Age at implantation (y) CIED type Pacemaker Pacemaker indication SND AVB ICD ICD indication Primary prevention Secondary prevention Lead location Atrium Ventricle Coronary sinus Death/transplant during follow-up
25 (60) 39 (23–48)
22 (56) 25 (18–41)
27 (49) 32 (23–48)
27 (64) 11 (26) 0 (0) 5 (12) 4 (10)
17 (44) 14 (36) 5 (13) 1 (3) 8 (21)
5 (9) 36 (65) 9 (16) 8 (15) 14 (25)
0 31 (74) 11 (26) 2 (1–2)
0 27 (69) 12 (31) 2 (1–3)
4 (7) 25 (45) 26 (47) 2 (1–3)
.568 .112 ,.001 – – – – – .011 – – – .267
39 (93) 1 (2) 2 (5) 1 (1–1) 31 (29–33)
35 (90) 1 (3) 3 (8) 1 (1–2) –
– – – – –
– – – – – –
5 (12) 27 (64) 10 (24) 19 (45) 30 (71) 13 4 2 11 23 (55) 40 (23–55)
– – – 16 (38) 26 (67) 12 5 1 8 14 (34) 33 (23–51)
– – – 5 (9) 27 (49) 2 13 2 7 12 (22) 33 (20–47)
13 (31)
10 (26)
9 4 7 (17)
8 2 4 (10)
8 0 4 (7)
– – –
6 1
1 3
1 3
– –
18 (43) 17 (40) 5 (12) 1 (2)
13 (33) 11 (28) 1 (3) 4 (10)
10 (18) 9 (16) 0 1 (2)
– – – .108
8 (15)
– – – ,.001 .956 – – – – .048 .803 .923 –
Values are presented as median (interquartile range) or as n (%). AVB 5 atrioventricular block; CHD 5 congenital heart disease; CIED 5 cardiac implantable electronic device; ICD 5 implantable cardioverter-defibrillator; RV 5 right ventricle; SND 5 sinus node dysfunction; TV 5 tricuspid valve; VSD 5 ventricular septal defect. *Flecainide, dronedarone, and sotalol.
Results One hundred thirty-six patients (42 ring/replacement, 39 repair, and 55 no TV surgery; median age 32 years [IQR 20 - 46]) were identified. Baseline patient characteristics are summarized in Table 1. Ebstein’s anomaly was the most common lesion after TV ring/replacement and TV repair (64% and 44%, respectively) and less frequently observed after no TV surgery (9%). Patients after TV surgery were characterized by less severe forms of congenital heart disease than those without TV surgery (28% vs 47% severe,
respectively; P 5 .03). Most patients underwent a single TV operation, although 21% underwent 2 operations (range 1–4). Overall, 180 catheter ablation procedures involving 239 tachycardias (mean 1.3 tachycardias per procedure) were performed and are listed in Table 2. The most commonly targeted substrate was CTI-IART in 87 (36%) of cases, non–CTI-IART in 69 (29%), focal AT in 42 (18%), and other forms of supraventricular tachyarrhythmia in 41 (17%). Procedures in patients with vs those without prior TV surgery
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Catheter ablation characteristics
Procedural characteristic
TV ring/replacement (n 5 64)
TV repair (n 5 50)
No TV surgery (n 5 66)
P
Number of procedures Number of ablation targets per procedure Isoproterenol used for induction 3D mapping system CARTO EnSite Other Long vascular sheath Procedure duration (h) Fluoroscopy time (min) Ablation characteristics Number of lesions Energy delivery (s) Irrigated energy Peak power (W)
2 (1–2) 1 (1–2)
1 (1–2) 1 (1–2)
1 (1–2) 1 (1–1)
.002 .03
15 (23) 59 (92) 40 14 5 23 (36) 4.3 (3.3–6.3) 29 (15–55)
14 (28) 47 (94) 36 9 2 14 (28) 4.4 (3.3–6.5) 20 (7–48)
12 (18) 63 (95) 43 18 2 25 (38) 3.4 (2.7–4.7) 14 (7–28)
.438 .522 – – – .503 .011 .003
23 (14–41) 991 (575–2204) 37 (58) 49 (40–50)
25 (14–38) 936 (529–1626) 25 (50) 40 (40–40)
20 (12–35) 947 (458–1620) 39 (59) 40 (40–40)
.421 .648 .499 .846
Values are presented as median (interquartile range) or as n (%). 3D 5 3-dimensional; TV 5 tricuspid valve.
were longer (4.3 hours vs 3.3 hours; P 5 .003) and required longer fluoroscopy time (31 minutes vs 18 minutes; P 5 .001). Complete procedural success was achieved in 51 (80%) of TV ring/replacement, 43 (86%) of TV repair, and 58 (88%) of no TV surgery group procedures. At least partial catheter ablation success was achieved in 51 (80%) of TV ring/replacement vs 47 and 62 (94% for both) TV repair and no TV surgery group procedures (P 5 .03). The difference in partial acute success was primarily driven by catheter ablation of annular substrates, with acute success of these targets in 33 (73%) of TV ring/replacement, 34 (92%) of TV repair, and 45 (94%) of no TV surgery procedures (P 5 .009) (Table 3). Successful catheter ablation of annular substrates required a modified approach in 19 (58%) TV ring/replacement vs 3 (10%) TV repair procedures (P , .001). These techniques were almost exclusively used for catheter ablation at the CTI in 18 of 19 procedures. Figure 2 depicts the chronological course and technical approach for catheter ablation of annular substrates in TV ring/replacement and TV repair group procedures. Despite additional lesion delivery from the ventricular aspect of the TV (with the catheter retroflexed under the valve), complete CTI block was not possible in 6 (33%) patients with TV ring/replacement. Of these, 3 could still be successfully targeted using previously described subvalvular approaches (2 subvalvular needle puncture and 1 coronary vein ablation).8,14 Table 3
Successful ablation of annular targets for those with a mechanical valve required a modified approach in only 1 patient, consisting of increased energy delivery. Overall, procedural complications occurred in 2 cases and 1 control, consisting of increased coronary sinus lead pacing threshold (n51), sinus node dysfunction requiring pacemaker implantation (n51), and skeletal muscular strain due to a prolonged procedure (n51). No TV damage related to these procedures was noted by routine echocardiography. Over a median follow-up duration of 3.0 years (IQR 2.0– 4.6 years), there were 48 (26%) recurrent tachycardias. Seventeen patients (6 TV ring/replacement, 4 TV repair, and 7 no TV surgery) were not followed at the participating centers after their procedure and were not included in the recurrence analysis. Multivariable analysis adjusting for patient age, lesion severity, and presence of CIED demonstrated an association between TV ring/replacement group status and recurrent tachycardia during follow-up (replacement vs no TV surgery: hazard ratio [HR] 2.4; 95% confidence interval [CI] 1.2–5.2; P 5 .009) but not between TV repair group status and recurrent tachycardia during follow-up (repair vs no TV surgery: HR 1.2; 95% CI 1.01–4.0; P 5 .604). There was an association between severe forms of congenital heart disease and tachycardia recurrence in the multivariable analysis (simple vs severe: HR 0.01; 95% CI 0.04–0.22; P , .001 and moderate vs severe: HR 1.0; 95% CI 0.8–1.5; P 5 .991).
Acute success for annular substrates by surgical category
Surgical category
Overall
Accessory pathway
AVNRT
CTI-IART
Focal AT
Ring/replacement Repair No TV surgery
33/45 (73)* 34/37 (92) 45/48 (94)
2/2 (100) 8/9 (89) 5/6 (83)
4/4 (100) 3/3 (100) 9/9 (100)
25/35 (71) 20/22 (91) 29/31 (94)
2/4 (50) 3/3 (100) 2/2 (100)
Values are presented as n/total n (%). AT 5 atrial tachycardia; AVNRT 5 atrioventricular nodal reentrant tachycardia; CTI 5 cavotricuspid isthmus; IART 5 intraatrial reentrant tachycardia; TV 5 tricuspid valve. *P 5 .001.
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Figure 2 Chronological flowchart for annular substrate ablation after tricuspid valve surgery. Modified approaches used to achieve successful catheter ablation are shown. “Ventricular aspect” refers to catheter ablation performed by passage of the catheter through the tricuspid valve annulus and prolapse of the catheter under the sewing ring. “Subvalvar approach” refers to puncture below the tricuspid valve or entry into a coronary vein in order to advance the ablation catheter under the sewing ring. “Higher power” refers to 50 W irrigated energy delivery. LOB 5 line of block; pt 5 patient.
The results of the unadjusted survival analysis depicting the relationship between surgical type and recurrence are presented in Figure 3. For patients with recurrent tachycardia undergoing repeat electrophysiology study, the proportions of initially targeted tachycardia substrates were not significantly different among the 3 surgical groups. Likewise, for repeat procedures, targeted arrhythmias were similarly distributed, albeit with CTI-IART responsible for a nonsignificantly higher proportion of recurrent tachycardias in replacement group patients
Figure 3
(11 [37%]) than in TV repair and no TV surgery groups (3 [30%] and 4 [31%], respectively) (see Figure 4 for a description of recurrent tachycardia characteristics).
Discussion
Key findings
The principal finding of this study is that catheter ablation of arrhythmia substrates in the vicinity of a surgically protected TV is more challenging than in those patients without prior
Kaplan-Meier curve depicting the development of recurrent tachycardia during follow-up. TV 5 tricuspid valve.
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Figure 4 Graph demonstrating the ablation targets for patients who underwent repeat procedures during the study period. Dark gray indicates tachycardia substrates at the index catheter ablation procedure, and light gray indicates those substrates targeted during the repeat procedure. CTI 5 cavotricuspid isthmus; IART 5 non-CTI intraatrial reentrant tachycardia; TV 5 tricuspid valve.
valve surgery. In particular, prosthetic valves or annuloplasty rings over the tricuspid annulus are associated with more complex procedures and suboptimal outcomes as compared with standard forms of surgical repair. These findings may be pertinent to the optimal perioperative management of patients with ACHD undergoing TV surgery.
this study was potentially underpowered to detect small differences between these groups, the present results are nonetheless encouraging. It is possible that the effect of suture annuloplasty and resulting tissue imbrication around the tricuspid annulus can be overcome with most forms of radiofrequency energy delivery, leading to adequate disruption of the underlying myocardial substrate in the majority of cases.
Efficacy of catheter ablation after TV repair Recently, there has been interest in the consequences of the cone operation for Ebstein’s anomaly and the subsequent ability to target postoperative supraventricular arrhythmias. Thus far, consensus has been mixed,3,4 with uncertainty regarding the optimal perioperative management for these patients. Importantly, there have been no large-scale comparative studies examining this issue, so a definite recommendation on whether to target potential electrophysiological substrates near the tricuspid annulus with catheter ablation before planned surgery has not been reached (currently a class IIb indication).15 The present investigation involved several large ACHD centers with extensive experience in catheter ablation in order to more definitively address this issue. Despite the multicenter study design, no difference in acute procedural success in patients with prior TV repair vs those without prior TV surgery was detected, suggesting that postoperative catheter-based interventions are likely to be similarly effective for these groups of patients. Although
Efficacy of catheter ablation after TV annuloplasty rings or TV replacement Catheter ablation after TV replacement or ring annuloplasty has not been well described, even though it may portend a significantly worse outcome in terms of catheter ablation efficacy. In theory, placement of a rigid surgical material over the tricuspid annulus could impair the operator’s ability to adequately target an underlying arrhythmia substrate, whether this be CTI-IART, other forms of AT, or a previously untreated accessory pathway.16 Such operations have become more common as patients with ACHD age, and anticipation of the potential ramifications of this surgery has become increasingly recognized. Overall, the present data support that surgery involving TV replacement or ring annuloplasty is an impediment to catheter ablation and that more complex procedures and inferior outcomes can be expected for this group. Procedures after TV surgery were longer and required greater fluoroscopy
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exposure and energy delivery, and those after TV ring/ replacement tended to be more invasive, often requiring more aggressive techniques for successful ablation. In particular, catheter ablation outcomes for annular substrates were significantly inferior after TV ring/replacement as compared with those after TV repair, despite similar baseline characteristics of these groups. Given these considerations, patients expected to undergo TV replacement or ring annuloplasty could be considered for preoperative electrophysiology study for the evaluation and treatment of existing tachycardia substrates near the TV annulus. Moreover, given the fact that CTI-IART may develop de novo postoperatively even in the face of a negative preoperative study,4 empirical catheter ablation of the CTI could be considered for these patients in order to prevent the unintended consequences of a future highly invasive or failed ablation. It is important to appreciate key differences in methodology between this study and those describing single-center case reports or series.5–7,14 Whereas the present study considered all catheter ablation procedures after TV ring annuloplasty or replacement (including those performed at outside institutions before catheter ablation at the participating center), single-center reports generally have only described local results. The present study may thus be more generalizable to the real-world experience after tricuspid replacement in patients with ACHD. Similar to these other reports, the present multicenter experience confirms that a modified approach is often necessary for successful catheter ablation of the CTI, highlighting the inherent complexities of catheter ablation for this group. In addition, successful catheter ablation was still not achieved despite rigorous ablation of both the atrial and ventricular components of the TV annulus in 6 patients in this multicenter study, with 3 patients proceeding to subvalvar ablation in order to achieve procedural success. Given potentially elevated risks associated with these extreme measures, careful preoperative assessment and empirical ablation of the CTI may be a reasonable approach before intended TV ring annuloplasty or replacement for patients with ACHD.
7 This afforded the opportunity to evaluate the impact of this type of surgery on tachycardia recurrence. These data suggest that despite acutely successful catheter ablation, tachycardia recurrence is particularly common after TV replacement or ring annuloplasty. The reasons for this finding are likely multifactorial. For instance, in patients who underwent repeat electrophysiological evaluation, tachycardia mechanisms were multiple and often involved regions other than those near the TV annulus. Moreover, the effects of valve degeneration and ensuing tricuspid stenosis or regurgitation likely contributed to atrial dilation and arrhythmogenesis during follow-up.
Limitations Within this case-control design, patients were matched as closely as possible according to major clinical factors, yet significant intergroup differences were still observed. Although many of these could be adjusted in the multivariable model, other unknown confounders could have potentially existed and could have affected the study results. In addition, because of its retrospective design, study data such as hemodynamic variables and preoperative electrophysiology study findings were inconsistently available. Future studies intended to investigate these additional issues may therefore be warranted after TV surgery for ACHD.
Conclusion After TV surgery, acute catheter ablation success was lower and tachycardia recurrence was higher for patients undergoing valve replacement or ring annuloplasty. Difficulty with access to annular substrates, especially the CTI, can be problematic in this population, and preoperative empirical ablation of this isthmus could be of value. The findings of this retrospective report support future larger multicenter series and prospective evaluation to determine the role of empirical annular substrate ablation in ACHD.
References TV surgery and recurrent tachycardia An unexpected finding was higher than anticipated recurrence in the surgical group undergoing TV replacement or ring annuloplasty. Recently, studies of catheter ablation outcomes in the population with ACHD have examined risk factors for recurrent tachycardia after successful catheter ablation.10–12 Predictors have included non–CTI-IART,10,11 atrial fibrillation history,10 lack of previous surgical Maze operation,11 or complex anatomy.12 Recurrence in these contemporary studies is reportedly in the range of 45%– 55% over a median follow-up duration of 3.5–4.5 years as compared with the 26% recurrence over 3.0 years noted in the present study. Unlike prior studies, the present study examined a large number of patients undergoing TV surgery and included a comparator group after TV replacement or ring annuloplasty.
1. Bouchardy J, Therrien J, Pilote L, et al. Atrial arrhythmias in adults with congenital heart disease. Circulation 2009;120:1679–1686. 2. Chan DP, Van Hare GF, Mackall JA, Carlson MDMD, Waldo AL. Importance of atrial flutter isthmus in postoperative intra-atrial reentrant tachycardia. Circulation 2000;102:1283–1289. 3. Shivapour JK, Sherwin ED, Alexander ME, et al. Utility of preoperative electrophysiologic studies in patients with Ebstein’s anomaly undergoing the cone procedure. Heart Rhythm 2014;11:182–186. 4. Wackel P, Cannon B, Dearani J, et al. Arrhythmia after cone repair for Ebstein anomaly: the Mayo Clinic experience in 143 young patients. Congenit Heart Dis 2018;13:26–30. 5. Traykov VB, Pap R, Bencsik G, Makai A, Forster T, Saghy L. Ventricular location of a part of the right atrial isthmus after tricuspid valve replacement for Ebstein’s anomaly: a challenge for atrial flutter ablation. J Interv Card Electrophysiol 2009;25:199–201. 6. Li CH, Lin YJ, Chen SA. Cavotricuspid isthmus ablation guided by electroanatomic mapping in a patient with a mechanical tricuspid valve replacement after a total correction of tetralogy of Fallot. J Cardiovasc Electrophysiol 2011; 22:938–940. 7. Yoshida N, Yamada T, McElderry HT, Kay GN. Successful cavotricuspid isthmus ablation in a patient with a Senning operation and prosthetic tricuspid valve replacement. J Cardiovasc Electrophysiol 2014;25:329–330.
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8 8. Gallotti RG, Shannon KM, Moore JP. Subvalvular catheter ablation of the cavotricuspid isthmus in a patient with Ebstein’s anomaly and tricuspid valve replacement. HeartRhythm Case Rep 2017;3:336–339. 9. Moore JP, Russell M, Mandapati R, Aboulhosn JA, Shannon KM. Catheter ablation of tachycardia arising from the pulmonary venous atrium after surgical repair of congenital heart disease. Heart Rhythm 2015;12:297–304. 10. Roca-Luque I, Rivas-Gandara N, Dos Subira L, et al. Long-term follow-up after ablation of intra-atrial re-entrant tachycardia in patients with congenital heart disease: types and predictors of recurrence. JACC Clin Electrophysiol 2018; 4:771–780. 11. Grubb CS, Lewis M, Whang W, et al. Catheter ablation for atrial tachycardia in adults with congenital heart disease. JACC Clin Electrophysiol 2019;5:438–447. 12. Klehs S, Schneider HE, Backhoff D, Paul T, Krause U. Radiofrequency catheter ablation of atrial tachycardias in congenital heart disease: results with special reference to complexity of underlying anatomy. Circ Arrhythm Electrophysiol 2017;10. 13. Warnes CA, Williams RG, Bashore TM, et al. ACC/AHA 2008 guidelines for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Develop Guidelines on the Management of Adults With Congenital Heart Disease). Developed in Collaboration With the American
14.
15.
16.
Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 2008; 52:e143–e263. Kella DK, Yasin OZ, Isath AM, et al. Radiofrequency ablation of the cavotricuspid isthmus for management of atrial flutter in patients with congenital heart disease after tricuspid valve surgery: a single-center experience. [published online ahead of print April 29, 2019]. Heart Rhythm, https://doi.org/10.1016/j.hrthm.2 019.04.045. Khairy P, Van Hare GF, Balaji S, et al. PACES/HRS expert consensus statement on the recognition and management of arrhythmias in adult congenital heart disease: developed in partnership between the Pediatric and Congenital Electrophysiology Society (PACES) and the Heart Rhythm Society (HRS). Endorsed by the governing bodies of PACES, HRS, the American College of Cardiology (ACC), the American Heart Association (AHA), the European Heart Rhythm Association (EHRA), the Canadian Heart Rhythm Society (CHRS), and the International Society for Adult Congenital Heart Disease (ISACHD). Heart Rhythm 2014; 11:e102–e165. Hassan A, Tan NY, Aung H, et al. Outcomes of atrial arrhythmia radiofrequency catheter ablation in patients with Ebstein’s anomaly. Europace 2018; 20:535–540.
Introduction Adult patients with congenital heart disease (ACHD) commonly develop atrial arrhythmias that are typically surgical scar-related reentry.1 Cavotricuspid isthmus (CTI)– related atrial flutter is the most commonly identified type of Address reprint requests and correspondence: Dr Jeremy P. Moore, UCLA Medical Center, Ahmanson/UCLA Adult Congenital Heart Disease Center, 100 Medical Plaza Dr Suite 770, Los Angeles, CA 90095. E-mail address: [email protected].
acute success was achieved in 81% of procedures in the TV ring/ replacement group vs 94% in both TV repair and no TV surgery groups (P 5 .03). The difference was driven mainly by ablation of annular substrates, with acute success in 73% of TV ring/replacement, 92% of TV repair, and 94% of no TV surgery groups (P 5 .01). Over a median of 3.0 years, tachycardia recurred after 26% of procedures. TV ring/replacement predicted recurrence in the multivariable analysis (hazard ratio 2.4; 95% confidence interval 1.2–5.2; P 5 .009). CONCLUSION After surgery for ACHD, catheter ablation success was lower and tachycardia recurrence was higher after TV valve ring/replacement surgery. The findings of this retrospective report support future larger multicenter series and prospective evaluation to determine the role of empirical annular substrate ablation. KEYWORDS Catheter ablation; Congenital heart disease; Ebstein’s anomaly; Ring annuloplasty; Tricuspid valve repair; Tricuspid valve replacement (Heart Rhythm 2019;-:1–8) Published by Elsevier Inc. on behalf of Heart Rhythm Society.
arrhythmia,2 yet other atrial arrhythmias can occur that are related to the atriotomy, atrial scar, and damaged tissue. Transection of the CTI using radiofrequency energy is still commonly used despite the type of congenital heart disease, and success rates are generally excellent. Surgical intervention on the tricuspid valve (TV) is often required in ACHD, with reports suggesting that this surgery may complicate subsequent catheter ablation of the CTI.3 There are no comparative data after TV repair,3,4 and there is a distinct paucity of data after TV replacement.
1547-5271/$-see front matter Published by Elsevier Inc. on behalf of Heart Rhythm Society.
https://doi.org/10.1016/j.hrthm.2019.07.020
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2
Figure 1 Illustration of technical difficulty with catheter ablation after tricuspid valve replacement. A portion of the atrial myocardium participating in the reentry circuit may be variably covered by the prosthetic material, hindering attempts to achieve permanent isthmus block.
Conceptually, after TV ring annuloplasty or replacement, a portion of the CTI may become covered by the bioprosthetic material and prevent complete linear ablation of this isthmus (Figure 1).5–9 Despite these considerations, the impact of TV surgery on procedural complexity has not been systematically studied.10–12 In order to clarify the effect of TV surgery on catheter ablation outcomes, a multicenter collaboration involving several experienced ACHD centers was developed. We sought to compare catheter ablation outcomes and procedural techniques for patients with atrial arrhythmias, with and without prior TV surgery.
Methods This was a retrospective study of patients with ACHD undergoing catheter ablation of supraventricular tachyarrhythmia between 2006 and 2018. Centers with experience in ACHD catheter ablation were provided the study protocol in October 2016, after which 7 centers agreed to participate. Data on all TV operations were collected and were recorded as either (1) isolated valve repair, (2) suture annuloplasty with or without valve repair, (3) ring annuloplasty with or without valve repair, or (4) TV replacement. Given the similar consequence of both TV replacement and ring annuloplasty on catheter ablation at the tricuspid annulus, patients undergoing these 2 surgical techniques were combined as 1 group. Similarly, those who underwent either suture annuloplasty or isolated TV repair were combined as 1 group, so ultimately 3 groups were considered for the purpose of the study: (1) TV ring/ replacement, (2) TV repair, and (3) no TV surgery. Patients with and without TV surgery were matched for age, class (biventricular, systemic right ventricular, or single ventricular heart disease), and time elapsed after surgery. Lesion severity was classified according to conventional criteria.13 Annular substrates were defined as those tachycardias that required catheter ablation of myocardium at the TV annulus. These included tricuspid annular focal atrial tachycardias (ATs), right-sided accessory pathways, atrioventricular nodal
reentrant tachycardia, and CTI-dependent intraatrial reentrant tachycardia (CTI-IART). After local ethics committee approval, all centers transmitted clinical data securely to the coordinating center at the University of California, Los Angeles through the Research Electronic Data Capture (REDCap) web application. One of the participating centers reported its own subgroup analysis separately during manuscript preparation, and these patients were included in the present report.14 The clinical variables of interest included patient demographic characteristics, congenital diagnoses, surgical indications, and details of TV surgery including concomitant Maze operation, need for cardiac implantable electronic device (CIED) placement, and administration of antiarrhythmic drug therapy. Catheter ablation details were collected and included the mechanism and location of the targeted arrhythmia for all cases. Particular attention was paid to any unique procedural approaches that were used in order to target tachycardia substrates near the surgically altered TV.
Outcomes Acute complete procedural success was defined as elimination of all stable inducible ATs during catheter ablation. Procedures in which 1 targeted tachycardia was eliminated but inducible tachycardia remained at the end of the procedure were labeled as acute partial success. Procedural complications were noted and specified in detail to the coordinating center for review. After catheter ablation, all patients were typically followed at the participating center at least annually. Symptoms possibly attributable to atrial tachyarrhythmia were evaluated by the treating physician per institutional protocol. Recurrence was defined as any sustained tachyarrhythmia (ie, lasting .30 seconds) demonstrated electrocardiographically or by CIED after an acutely successful catheter ablation procedure. Patients undergoing failed catheter ablation (ie, lack of partial or complete success at the index procedure) were excluded from the recurrence analysis.
Statistical analysis Data are presented as median (interquartile range [IQR]) for continuous variables and as frequency (percentage) for dichotomous variables. For surgical group comparisons, the Wilcoxon rank-sum method was used for continuous variables and the Fisher exact test for categorical variables. To evaluate an association between surgical groups and acute procedural success, the Pearson c2 test was used. For tachycardia recurrence, a Cox proportional hazards model was created that incorporated class of TV surgery as a covariate, with adjustment for additional covariates associated with a P value of ,.1 in the univariable analysis. In order to assess the validity of treating each catheter ablation procedure as an independent event, generalized estimating equation analysis was used in the multivariable analysis. A P value of ,.05 is regarded as significant. Statistical analyses were performed with JMP software version 14.0 and SAS version 9.4 (SAS Institute Inc., Cary, NC).
Moore et al Table 1
Catheter Ablation After Tricuspid Surgery
3
Baseline population characteristics grouped by prior surgical strategy
Patient characteristic
TV ring/replacement (n 5 42)
TV repair (n 5 39)
No TV surgery (n 5 55)
P
Sex: male Age at catheter ablation (y) CHD type Ebstein’s anomaly Tetralogy of Fallot/VSD Single ventricle Systemic RV Other CHD severity Simple Moderate Severe/complex Number of CHD operations Tricuspid valve surgery Surgical indication Regurgitation Stenosis Mixed disease Number of TV operations Valve size (mm) Valve type Mechanical Bioprosthetic Ring annuloplasty Maze operation Antiarrhythmic drugs b-Blocker Amiodarone Digoxin Other* CIED placement Age at implantation (y) CIED type Pacemaker Pacemaker indication SND AVB ICD ICD indication Primary prevention Secondary prevention Lead location Atrium Ventricle Coronary sinus Death/transplant during follow-up
25 (60) 39 (23–48)
22 (56) 25 (18–41)
27 (49) 32 (23–48)
27 (64) 11 (26) 0 (0) 5 (12) 4 (10)
17 (44) 14 (36) 5 (13) 1 (3) 8 (21)
5 (9) 36 (65) 9 (16) 8 (15) 14 (25)
0 31 (74) 11 (26) 2 (1–2)
0 27 (69) 12 (31) 2 (1–3)
4 (7) 25 (45) 26 (47) 2 (1–3)
.568 .112 ,.001 – – – – – .011 – – – .267
39 (93) 1 (2) 2 (5) 1 (1–1) 31 (29–33)
35 (90) 1 (3) 3 (8) 1 (1–2) –
– – – – –
– – – – – –
5 (12) 27 (64) 10 (24) 19 (45) 30 (71) 13 4 2 11 23 (55) 40 (23–55)
– – – 16 (38) 26 (67) 12 5 1 8 14 (34) 33 (23–51)
– – – 5 (9) 27 (49) 2 13 2 7 12 (22) 33 (20–47)
13 (31)
10 (26)
9 4 7 (17)
8 2 4 (10)
8 0 4 (7)
– – –
6 1
1 3
1 3
– –
18 (43) 17 (40) 5 (12) 1 (2)
13 (33) 11 (28) 1 (3) 4 (10)
10 (18) 9 (16) 0 1 (2)
– – – .108
8 (15)
– – – ,.001 .956 – – – – .048 .803 .923 –
Values are presented as median (interquartile range) or as n (%). AVB 5 atrioventricular block; CHD 5 congenital heart disease; CIED 5 cardiac implantable electronic device; ICD 5 implantable cardioverter-defibrillator; RV 5 right ventricle; SND 5 sinus node dysfunction; TV 5 tricuspid valve; VSD 5 ventricular septal defect. *Flecainide, dronedarone, and sotalol.
Results One hundred thirty-six patients (42 ring/replacement, 39 repair, and 55 no TV surgery; median age 32 years [IQR 20 - 46]) were identified. Baseline patient characteristics are summarized in Table 1. Ebstein’s anomaly was the most common lesion after TV ring/replacement and TV repair (64% and 44%, respectively) and less frequently observed after no TV surgery (9%). Patients after TV surgery were characterized by less severe forms of congenital heart disease than those without TV surgery (28% vs 47% severe,
respectively; P 5 .03). Most patients underwent a single TV operation, although 21% underwent 2 operations (range 1–4). Overall, 180 catheter ablation procedures involving 239 tachycardias (mean 1.3 tachycardias per procedure) were performed and are listed in Table 2. The most commonly targeted substrate was CTI-IART in 87 (36%) of cases, non–CTI-IART in 69 (29%), focal AT in 42 (18%), and other forms of supraventricular tachyarrhythmia in 41 (17%). Procedures in patients with vs those without prior TV surgery
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4 Table 2
Catheter ablation characteristics
Procedural characteristic
TV ring/replacement (n 5 64)
TV repair (n 5 50)
No TV surgery (n 5 66)
P
Number of procedures Number of ablation targets per procedure Isoproterenol used for induction 3D mapping system CARTO EnSite Other Long vascular sheath Procedure duration (h) Fluoroscopy time (min) Ablation characteristics Number of lesions Energy delivery (s) Irrigated energy Peak power (W)
2 (1–2) 1 (1–2)
1 (1–2) 1 (1–2)
1 (1–2) 1 (1–1)
.002 .03
15 (23) 59 (92) 40 14 5 23 (36) 4.3 (3.3–6.3) 29 (15–55)
14 (28) 47 (94) 36 9 2 14 (28) 4.4 (3.3–6.5) 20 (7–48)
12 (18) 63 (95) 43 18 2 25 (38) 3.4 (2.7–4.7) 14 (7–28)
.438 .522 – – – .503 .011 .003
23 (14–41) 991 (575–2204) 37 (58) 49 (40–50)
25 (14–38) 936 (529–1626) 25 (50) 40 (40–40)
20 (12–35) 947 (458–1620) 39 (59) 40 (40–40)
.421 .648 .499 .846
Values are presented as median (interquartile range) or as n (%). 3D 5 3-dimensional; TV 5 tricuspid valve.
were longer (4.3 hours vs 3.3 hours; P 5 .003) and required longer fluoroscopy time (31 minutes vs 18 minutes; P 5 .001). Complete procedural success was achieved in 51 (80%) of TV ring/replacement, 43 (86%) of TV repair, and 58 (88%) of no TV surgery group procedures. At least partial catheter ablation success was achieved in 51 (80%) of TV ring/replacement vs 47 and 62 (94% for both) TV repair and no TV surgery group procedures (P 5 .03). The difference in partial acute success was primarily driven by catheter ablation of annular substrates, with acute success of these targets in 33 (73%) of TV ring/replacement, 34 (92%) of TV repair, and 45 (94%) of no TV surgery procedures (P 5 .009) (Table 3). Successful catheter ablation of annular substrates required a modified approach in 19 (58%) TV ring/replacement vs 3 (10%) TV repair procedures (P , .001). These techniques were almost exclusively used for catheter ablation at the CTI in 18 of 19 procedures. Figure 2 depicts the chronological course and technical approach for catheter ablation of annular substrates in TV ring/replacement and TV repair group procedures. Despite additional lesion delivery from the ventricular aspect of the TV (with the catheter retroflexed under the valve), complete CTI block was not possible in 6 (33%) patients with TV ring/replacement. Of these, 3 could still be successfully targeted using previously described subvalvular approaches (2 subvalvular needle puncture and 1 coronary vein ablation).8,14 Table 3
Successful ablation of annular targets for those with a mechanical valve required a modified approach in only 1 patient, consisting of increased energy delivery. Overall, procedural complications occurred in 2 cases and 1 control, consisting of increased coronary sinus lead pacing threshold (n51), sinus node dysfunction requiring pacemaker implantation (n51), and skeletal muscular strain due to a prolonged procedure (n51). No TV damage related to these procedures was noted by routine echocardiography. Over a median follow-up duration of 3.0 years (IQR 2.0– 4.6 years), there were 48 (26%) recurrent tachycardias. Seventeen patients (6 TV ring/replacement, 4 TV repair, and 7 no TV surgery) were not followed at the participating centers after their procedure and were not included in the recurrence analysis. Multivariable analysis adjusting for patient age, lesion severity, and presence of CIED demonstrated an association between TV ring/replacement group status and recurrent tachycardia during follow-up (replacement vs no TV surgery: hazard ratio [HR] 2.4; 95% confidence interval [CI] 1.2–5.2; P 5 .009) but not between TV repair group status and recurrent tachycardia during follow-up (repair vs no TV surgery: HR 1.2; 95% CI 1.01–4.0; P 5 .604). There was an association between severe forms of congenital heart disease and tachycardia recurrence in the multivariable analysis (simple vs severe: HR 0.01; 95% CI 0.04–0.22; P , .001 and moderate vs severe: HR 1.0; 95% CI 0.8–1.5; P 5 .991).
Acute success for annular substrates by surgical category
Surgical category
Overall
Accessory pathway
AVNRT
CTI-IART
Focal AT
Ring/replacement Repair No TV surgery
33/45 (73)* 34/37 (92) 45/48 (94)
2/2 (100) 8/9 (89) 5/6 (83)
4/4 (100) 3/3 (100) 9/9 (100)
25/35 (71) 20/22 (91) 29/31 (94)
2/4 (50) 3/3 (100) 2/2 (100)
Values are presented as n/total n (%). AT 5 atrial tachycardia; AVNRT 5 atrioventricular nodal reentrant tachycardia; CTI 5 cavotricuspid isthmus; IART 5 intraatrial reentrant tachycardia; TV 5 tricuspid valve. *P 5 .001.
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Catheter Ablation After Tricuspid Surgery
5
Figure 2 Chronological flowchart for annular substrate ablation after tricuspid valve surgery. Modified approaches used to achieve successful catheter ablation are shown. “Ventricular aspect” refers to catheter ablation performed by passage of the catheter through the tricuspid valve annulus and prolapse of the catheter under the sewing ring. “Subvalvar approach” refers to puncture below the tricuspid valve or entry into a coronary vein in order to advance the ablation catheter under the sewing ring. “Higher power” refers to 50 W irrigated energy delivery. LOB 5 line of block; pt 5 patient.
The results of the unadjusted survival analysis depicting the relationship between surgical type and recurrence are presented in Figure 3. For patients with recurrent tachycardia undergoing repeat electrophysiology study, the proportions of initially targeted tachycardia substrates were not significantly different among the 3 surgical groups. Likewise, for repeat procedures, targeted arrhythmias were similarly distributed, albeit with CTI-IART responsible for a nonsignificantly higher proportion of recurrent tachycardias in replacement group patients
Figure 3
(11 [37%]) than in TV repair and no TV surgery groups (3 [30%] and 4 [31%], respectively) (see Figure 4 for a description of recurrent tachycardia characteristics).
Discussion
Key findings
The principal finding of this study is that catheter ablation of arrhythmia substrates in the vicinity of a surgically protected TV is more challenging than in those patients without prior
Kaplan-Meier curve depicting the development of recurrent tachycardia during follow-up. TV 5 tricuspid valve.
6
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Figure 4 Graph demonstrating the ablation targets for patients who underwent repeat procedures during the study period. Dark gray indicates tachycardia substrates at the index catheter ablation procedure, and light gray indicates those substrates targeted during the repeat procedure. CTI 5 cavotricuspid isthmus; IART 5 non-CTI intraatrial reentrant tachycardia; TV 5 tricuspid valve.
valve surgery. In particular, prosthetic valves or annuloplasty rings over the tricuspid annulus are associated with more complex procedures and suboptimal outcomes as compared with standard forms of surgical repair. These findings may be pertinent to the optimal perioperative management of patients with ACHD undergoing TV surgery.
this study was potentially underpowered to detect small differences between these groups, the present results are nonetheless encouraging. It is possible that the effect of suture annuloplasty and resulting tissue imbrication around the tricuspid annulus can be overcome with most forms of radiofrequency energy delivery, leading to adequate disruption of the underlying myocardial substrate in the majority of cases.
Efficacy of catheter ablation after TV repair Recently, there has been interest in the consequences of the cone operation for Ebstein’s anomaly and the subsequent ability to target postoperative supraventricular arrhythmias. Thus far, consensus has been mixed,3,4 with uncertainty regarding the optimal perioperative management for these patients. Importantly, there have been no large-scale comparative studies examining this issue, so a definite recommendation on whether to target potential electrophysiological substrates near the tricuspid annulus with catheter ablation before planned surgery has not been reached (currently a class IIb indication).15 The present investigation involved several large ACHD centers with extensive experience in catheter ablation in order to more definitively address this issue. Despite the multicenter study design, no difference in acute procedural success in patients with prior TV repair vs those without prior TV surgery was detected, suggesting that postoperative catheter-based interventions are likely to be similarly effective for these groups of patients. Although
Efficacy of catheter ablation after TV annuloplasty rings or TV replacement Catheter ablation after TV replacement or ring annuloplasty has not been well described, even though it may portend a significantly worse outcome in terms of catheter ablation efficacy. In theory, placement of a rigid surgical material over the tricuspid annulus could impair the operator’s ability to adequately target an underlying arrhythmia substrate, whether this be CTI-IART, other forms of AT, or a previously untreated accessory pathway.16 Such operations have become more common as patients with ACHD age, and anticipation of the potential ramifications of this surgery has become increasingly recognized. Overall, the present data support that surgery involving TV replacement or ring annuloplasty is an impediment to catheter ablation and that more complex procedures and inferior outcomes can be expected for this group. Procedures after TV surgery were longer and required greater fluoroscopy
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exposure and energy delivery, and those after TV ring/ replacement tended to be more invasive, often requiring more aggressive techniques for successful ablation. In particular, catheter ablation outcomes for annular substrates were significantly inferior after TV ring/replacement as compared with those after TV repair, despite similar baseline characteristics of these groups. Given these considerations, patients expected to undergo TV replacement or ring annuloplasty could be considered for preoperative electrophysiology study for the evaluation and treatment of existing tachycardia substrates near the TV annulus. Moreover, given the fact that CTI-IART may develop de novo postoperatively even in the face of a negative preoperative study,4 empirical catheter ablation of the CTI could be considered for these patients in order to prevent the unintended consequences of a future highly invasive or failed ablation. It is important to appreciate key differences in methodology between this study and those describing single-center case reports or series.5–7,14 Whereas the present study considered all catheter ablation procedures after TV ring annuloplasty or replacement (including those performed at outside institutions before catheter ablation at the participating center), single-center reports generally have only described local results. The present study may thus be more generalizable to the real-world experience after tricuspid replacement in patients with ACHD. Similar to these other reports, the present multicenter experience confirms that a modified approach is often necessary for successful catheter ablation of the CTI, highlighting the inherent complexities of catheter ablation for this group. In addition, successful catheter ablation was still not achieved despite rigorous ablation of both the atrial and ventricular components of the TV annulus in 6 patients in this multicenter study, with 3 patients proceeding to subvalvar ablation in order to achieve procedural success. Given potentially elevated risks associated with these extreme measures, careful preoperative assessment and empirical ablation of the CTI may be a reasonable approach before intended TV ring annuloplasty or replacement for patients with ACHD.
7 This afforded the opportunity to evaluate the impact of this type of surgery on tachycardia recurrence. These data suggest that despite acutely successful catheter ablation, tachycardia recurrence is particularly common after TV replacement or ring annuloplasty. The reasons for this finding are likely multifactorial. For instance, in patients who underwent repeat electrophysiological evaluation, tachycardia mechanisms were multiple and often involved regions other than those near the TV annulus. Moreover, the effects of valve degeneration and ensuing tricuspid stenosis or regurgitation likely contributed to atrial dilation and arrhythmogenesis during follow-up.
Limitations Within this case-control design, patients were matched as closely as possible according to major clinical factors, yet significant intergroup differences were still observed. Although many of these could be adjusted in the multivariable model, other unknown confounders could have potentially existed and could have affected the study results. In addition, because of its retrospective design, study data such as hemodynamic variables and preoperative electrophysiology study findings were inconsistently available. Future studies intended to investigate these additional issues may therefore be warranted after TV surgery for ACHD.
Conclusion After TV surgery, acute catheter ablation success was lower and tachycardia recurrence was higher for patients undergoing valve replacement or ring annuloplasty. Difficulty with access to annular substrates, especially the CTI, can be problematic in this population, and preoperative empirical ablation of this isthmus could be of value. The findings of this retrospective report support future larger multicenter series and prospective evaluation to determine the role of empirical annular substrate ablation in ACHD.
References TV surgery and recurrent tachycardia An unexpected finding was higher than anticipated recurrence in the surgical group undergoing TV replacement or ring annuloplasty. Recently, studies of catheter ablation outcomes in the population with ACHD have examined risk factors for recurrent tachycardia after successful catheter ablation.10–12 Predictors have included non–CTI-IART,10,11 atrial fibrillation history,10 lack of previous surgical Maze operation,11 or complex anatomy.12 Recurrence in these contemporary studies is reportedly in the range of 45%– 55% over a median follow-up duration of 3.5–4.5 years as compared with the 26% recurrence over 3.0 years noted in the present study. Unlike prior studies, the present study examined a large number of patients undergoing TV surgery and included a comparator group after TV replacement or ring annuloplasty.
1. Bouchardy J, Therrien J, Pilote L, et al. Atrial arrhythmias in adults with congenital heart disease. Circulation 2009;120:1679–1686. 2. Chan DP, Van Hare GF, Mackall JA, Carlson MDMD, Waldo AL. Importance of atrial flutter isthmus in postoperative intra-atrial reentrant tachycardia. Circulation 2000;102:1283–1289. 3. Shivapour JK, Sherwin ED, Alexander ME, et al. Utility of preoperative electrophysiologic studies in patients with Ebstein’s anomaly undergoing the cone procedure. Heart Rhythm 2014;11:182–186. 4. Wackel P, Cannon B, Dearani J, et al. Arrhythmia after cone repair for Ebstein anomaly: the Mayo Clinic experience in 143 young patients. Congenit Heart Dis 2018;13:26–30. 5. Traykov VB, Pap R, Bencsik G, Makai A, Forster T, Saghy L. Ventricular location of a part of the right atrial isthmus after tricuspid valve replacement for Ebstein’s anomaly: a challenge for atrial flutter ablation. J Interv Card Electrophysiol 2009;25:199–201. 6. Li CH, Lin YJ, Chen SA. Cavotricuspid isthmus ablation guided by electroanatomic mapping in a patient with a mechanical tricuspid valve replacement after a total correction of tetralogy of Fallot. J Cardiovasc Electrophysiol 2011; 22:938–940. 7. Yoshida N, Yamada T, McElderry HT, Kay GN. Successful cavotricuspid isthmus ablation in a patient with a Senning operation and prosthetic tricuspid valve replacement. J Cardiovasc Electrophysiol 2014;25:329–330.
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8 8. Gallotti RG, Shannon KM, Moore JP. Subvalvular catheter ablation of the cavotricuspid isthmus in a patient with Ebstein’s anomaly and tricuspid valve replacement. HeartRhythm Case Rep 2017;3:336–339. 9. Moore JP, Russell M, Mandapati R, Aboulhosn JA, Shannon KM. Catheter ablation of tachycardia arising from the pulmonary venous atrium after surgical repair of congenital heart disease. Heart Rhythm 2015;12:297–304. 10. Roca-Luque I, Rivas-Gandara N, Dos Subira L, et al. Long-term follow-up after ablation of intra-atrial re-entrant tachycardia in patients with congenital heart disease: types and predictors of recurrence. JACC Clin Electrophysiol 2018; 4:771–780. 11. Grubb CS, Lewis M, Whang W, et al. Catheter ablation for atrial tachycardia in adults with congenital heart disease. JACC Clin Electrophysiol 2019;5:438–447. 12. Klehs S, Schneider HE, Backhoff D, Paul T, Krause U. Radiofrequency catheter ablation of atrial tachycardias in congenital heart disease: results with special reference to complexity of underlying anatomy. Circ Arrhythm Electrophysiol 2017;10. 13. Warnes CA, Williams RG, Bashore TM, et al. ACC/AHA 2008 guidelines for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Develop Guidelines on the Management of Adults With Congenital Heart Disease). Developed in Collaboration With the American
14.
15.
16.
Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 2008; 52:e143–e263. Kella DK, Yasin OZ, Isath AM, et al. Radiofrequency ablation of the cavotricuspid isthmus for management of atrial flutter in patients with congenital heart disease after tricuspid valve surgery: a single-center experience. [published online ahead of print April 29, 2019]. Heart Rhythm, https://doi.org/10.1016/j.hrthm.2 019.04.045. Khairy P, Van Hare GF, Balaji S, et al. PACES/HRS expert consensus statement on the recognition and management of arrhythmias in adult congenital heart disease: developed in partnership between the Pediatric and Congenital Electrophysiology Society (PACES) and the Heart Rhythm Society (HRS). Endorsed by the governing bodies of PACES, HRS, the American College of Cardiology (ACC), the American Heart Association (AHA), the European Heart Rhythm Association (EHRA), the Canadian Heart Rhythm Society (CHRS), and the International Society for Adult Congenital Heart Disease (ISACHD). Heart Rhythm 2014; 11:e102–e165. Hassan A, Tan NY, Aung H, et al. Outcomes of atrial arrhythmia radiofrequency catheter ablation in patients with Ebstein’s anomaly. Europace 2018; 20:535–540.