A Hybrid Approach for Persistent Atrial Fibrillation
© 2024 HMP Global. All Rights Reserved.
Any views and opinions expressed are those of the author(s) and/or participants and do not necessarily reflect the views, policy, or position of EP Lab Digest or HMP Global, their employees, and affiliates.
EP LAB DIGEST. 2024;24(8):22-23.
Sunthosh V Parvathaneni, MD, FACC, FHRS; and Dante A Dali, DO, FACS
Mercy Hospital Springfield, Springfield, Missouri
Atrial fibrillation (AF) has become increasingly prevalent, affecting approximately 6 million people in the United States and 33 million worldwide. Of those affected, 70% are considered to have persistent AF (PAF), which is defined as continuous AF lasting >7 days, or long-standing persistent AF (LSPAF), defined as lasting >12 months. Pulmonary vein isolation (PVI) with catheter ablation has been shown to be effective in paroxysmal AF, but catheter ablation for PAF has been less efficacious, likely due to pathology related to both trigger and substrate. The Cox-Maze procedure has shown success for treating PAF; however, it is usually performed concomitantly with an open-chest cardiac surgical procedure. Its success has led to the need to develop a minimally invasive alternative that can offer similar results but performed safely as a stand-alone procedure. Because of this, hybrid ablation therapies have become more prevalent within the last decade. Hybrid options encompass a totally thoracoscopic approach and include the hybrid Convergent procedure, in which epicardial ablation of the posterior wall is performed from a pericardial approach followed by an endocardial approach via percutaneous catheter ablation. The results of the CONVERGE trial showed the success of the approach, with hybrid Convergent ablation having improved efficacy compared to catheter ablation in LSPAF through 12-month follow-up, with the difference maintained through 18 months postprocedure, with the understanding that posterior wall isolation was not included in the control arm, but linear roof and complex fractionated atrial electrogram lesions were allowed.1,2 Herein, we present a case illustrating a successful hybrid Convergent approach.
Case Presentation
A 49-year-old man was referred to the electrophysiology (EP) clinic with complaints of chronic fatigue, dizziness, chest pain, and exercise intolerance, including during the jujitsu class that he taught. While he had been experiencing these symptoms for the past 6 years, the duration of symptoms had grown progressively longer, and he was now feeling them constantly. His relevant past medical history included hypertension, dyslipidemia, obstructive sleep apnea, and obesity. His relevant medications included apixaban 5 mg twice daily, metoprolol 50 mg twice daily, diltiazem 180 mg twice daily, and flecainide 100 mg twice daily. On presentation, the patient was in AF. An additional attempt at rhythm restoration with amiodarone was made, but this failed cardioversion resulted in persistence of AF. He had not had prior catheter ablation.
The patient was then referred to cardiac surgery for evaluation for the hybrid Convergent procedure. The patient underwent routine preoperative evaluation with review of the chart for any recent cardiac risk stratification, evaluation with echocardiogram, and cardiac computed tomography angiography (CTA). The cardiac CTA revealed normal coronary arteries and a left atrial (LA) size of 4.9 cm along with 4 distinct PVs. He was deemed a candidate for the hybrid Convergent procedure.
The hybrid Convergent procedure is performed as a staged approach. The cardiac surgeon performs epicardial PV and LA posterior wall ablation
and epicardial LA appendage (LAA) closure; then, 45 days later, the electrophysiologist performs endocardial LA ablation to address gaps and additional LA substrate along with a right-sided cavotricuspid isthmus (CTI) ablation, if needed. Prior to procedure, the patient underwent intraoperative transesophageal echocardiogram (TEE) to evaluate for the presence of thrombus in the LA. During the surgical portion of the procedure, an endoscopic subxiphoid approach was used through the pericardial space and a 23-lesion set was completed, some of which were double applications utilizing the EPi-Sense system (AtriCure, Inc) (Figure 1). During ablation, some anatomical difficulties were noted due to the prominence of the patient’s spine and oblique sinus reflections. After completion of the epicardial ablation, the LAA was excluded with the AtriClip (AtriCure, Inc) via a thoracoscopic approach. At the end of the surgical portion of the procedure, the patient was successfully cardioverted to sinus bradycardia. The patient did well postoperatively, all drains and chest tubes were removed, and he was discharged home in sinus rhythm on postoperative day 2. There were no complications from the surgical portion of the procedure.
The endocardial portion of the procedure occurred 45 days later in the EP laboratory. The patient underwent routine preoperative TEE to assess
the LA, LA thrombus, and success of the LAA closure. The patient presented in AF. The patient was placed under general anesthesia and successfully cardioverted to sinus rhythm. Radiofrequency (RF) ablation of the CTI with the TactiCath Contact Force Ablation Catheter, Sensor Enabled (Abbott) was performed, which demonstrated medial to lateral block of about 151 ms. Block across the linear ablation line was confirmed with the EnSite X System (Abbott). We then proceeded to the LA via transseptal puncture with the VersaCross Transseptal Platform (Baylis Medical). Mapping of the LA was performed utilizing the Advisor HD Grid Mapping Catheter, Sensor Enabled (Abbott). The pre-LA endocardial ablation map (Figure 2) showed areas of scar creation near the middle of the posterior wall but healthier tissue near the veins, as well as areas of the epicardial region where there was some difficulty. The Advisor HD Grid catheter was then exchanged for the Arctic Front cryoballoon catheter (Medtronic) to allow for single-shot ablation of the PVs. After PVI, the system was exchanged for the Advisor HD Grid catheter and mapping was again performed in the LA. The additional lesion sets from PVI were displayed on the map and the Advisor HD Grid catheter was exchanged for the TactiCath catheter. Linear RF lesions were then made across the roof connecting the left and right superior PVs as well as the floor of the LA connecting the left and right inferior PVs. There were a few areas of presumed epicardial breakthrough points on the posterior wall, and further RF applications in those areas resulted in complete posterior wall isolation (Figure 3). Once complete, another EP study was performed with isoproterenol infusion and no additional arrhythmias were inducible. All catheters and sheaths were removed, and hemostasis was achieved with a figure-of-8 suture. There were no complications from the endocardial portion of the procedure. The patient was ambulatory within 2 hours and discharged home the day of the procedure.
The patient underwent routine follow-up visits at 3 and 6 months postprocedure, and has not experienced recurrence of AF or symptoms. Monitoring was performed with a 1-month event monitor. His CHA2DS2-VASc score is 1, and given his risk factors for stroke and the presence of the LA clip, the apixaban was stopped. He has returned to his usual activities, including teaching jujitsu.
Discussion
AF is a growing epidemic across the world, and the rates of new cases continue to rise. While PVI has been effective for treating paroxysmal AF,
treatment of PAF has proven difficult due to varying single-procedure success and the need for multiple procedures. In 2015, the STAR AF II investigators evaluated endocardial success with PVI alone versus PVI plus linear ablation or PVI plus complex electrogram ablation; the trial demonstrated no reduction in recurrence of AF when either linear ablation or ablation of complex fractionated electrograms was performed in addition to PVI.3 The randomized CAPLA trial also showed no significant decrease in recurrence with posterior wall isolation adjunctive to PVI for PAF.4 Therefore, a completely endocardial ablation may not be the best implemented strategy for PAF. With the positive results of the CONVERGE trial and other observational studies on hybrid Convergent ablation, more success is being seen with a hybrid approach with concomitant LA clip placement for advanced AF.1,2,5-7,10 Patient selection is important to the success of the procedure, and there are patient and anatomical limitations to consider for the hybrid Convergent procedure.8,9 Patients who have already had open chest procedures or those who have had pericardial access are excluded from the procedure. Anatomically, spinal and pericardial adhesions and epicardial fat along with the oblique sinus pose challenges.
Success of hybrid therapies over pure endocardial posterior wall isolation leaves questions about the impact of the epicardial component to AF management. The gold standard Cox-Maze procedure, with a cut-sew technique along with LAA ligation, showed high rates of effectiveness due to the true transmural nature of the lesion set. However, due to the increased morbidity of a stand-alone Cox-Maze procedure, a hybrid approach is more likely to mimic these results with much less morbidity, as demonstrated by the CONVERGE trial. Further, with newer technology such as pulsed field ablation on the horizon, there will still be a role for a collaborative hybrid approach in the future.
Conclusion
We reviewed a case of a patient with LSPAF who failed 2 antiarrhythmic medications and underwent successful hybrid Convergent ablation. A hybrid approach can address both triggers and the underlying endocardial and epicardial substrate for optimal success in reduction of AF burden in patients with LSPAF.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest and report no conflicts of interest regarding the content herein. Dr Parvathaneni reports participation on and consulting fees for the Medtronic Advisory Board.
References
1. DeLurgio DB, Crossen KJ, Gill J, et al. Hybrid Convergent procedure for the treatment of persistent and long-standing persistent atrial fibrillation: results of CONVERGE clinical trial. Circ Arrhythm Electrophysiol. 2020;13(12):e009288. doi:10.1161/CIRCEP.120.009288
2. DeLurgio DB, Blauth C, Halkos ME, et al. Hybrid epicardial-endocardial ablation for long-standing persistent atrial fibrillation: a subanalysis of the CONVERGE Trial. Heart Rhythm O2. 2023;4(2):111-118. doi:10.1016/j.hroo.2022.11.007
3. Verma A, Jiang CY, Betts TR, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med. 2015;372(19):1812-1822. doi:10.1056/NEJMoa1408288
4. Kistler PM, Chieng D, Sugumar H, et al. Effect of catheter ablation using pulmonary vein isolation with vs without posterior left atrial wall isolation on atrial arrhythmia recurrence in patients with persistent atrial fibrillation: the CAPLA randomized clinical trial. JAMA. 2023;329(2):127-135. doi:10.1001/jama.2022.23722
5. Shrestha S, Plasseraud KM, Makati K, et al. Hybrid Convergent ablation for atrial fibrillation: a systematic review and meta-analysis. Heart Rhythm O2. 2022;3(4):396-404. doi:10.1016/j.hroo.2022.05.006
6. Mannakkara NN, Porter B, Child N, et al. Convergent ablation for persistent atrial fibrillation: outcomes from a single-centre real-world experience. Eur J Cardiothorac Surg. 2022;63(1):ezac515. doi:10.1093/ejcts/ezac515
7. Carpenter A, Pannell LMK, Rizvi SIA, et al. Convergent approach to persistent atrial fibrillation ablation: long-term single-centre safety and efficacy. Front Cardiovasc Med. 2023;10:1336801. doi:10.3389/fcvm.2023.1336801
8. De Lurgio DB. Selection of patients for hybrid ablation procedure. J Cardiovasc Electrophysiol. 2023;34(10):2179-2187. doi:10.1111/jce.15901
9. De Lurgio DB, Meador MR. Hybrid ablation procedures of atrial fibrillation—how to optimize patient selection and improve the procedural approach. Curr Cardiovasc Risk Rep. 2023;17(7):133-141. doi:10.1007/s12170-023-00722-5
10. Gegechkori N, Yang F, Jacobowitz I, et al. The effect of left atrial appendage closure on patients undergoing hybrid / convergent atrial fibrillation ablation. J Atr Fibrillation. 2022;15(3):66-71.
