Setting Up a Convergent Hybrid Atrial Fibrillation Ablation Program

The electrophysiologists at St. Francis Hospital, a member of Trinity Health of New England, have been performing catheter ablation procedures to treat atrial fibrillation for the past 15 years. In parallel, our cardiothoracic surgeons have treated atrial fibrillation using surgical techniques, from the full surgical Maze procedure to radiofrequency or cryothermal pulmonary vein isolation, in select patients. Unsurprisingly, the volume of patients treated surgically has declined over the years as the techniques for catheter-based treatment of atrial fibrillation have developed and outcomes improved.

Over the past year, we have developed a program for hybrid surgical/catheter ablation for atrial fibrillation utilizing the Convergent procedure. With the limited efficacy of catheter ablation for patients with persistent atrial fibrillation, and the publication of the CONVERGE trial demonstrating the superiority of this approach compared with standard catheter-based ablation for patients with persistent and longstanding persistent atrial fibrillation, this approach provides us with an excellent new option for the treatment of select patients. With a close collaboration between the cardiac arrhythmia service and the cardiothoracic surgical team, we have been able to develop an efficient approach for the use of this procedure.

Case Presentation

The patient is a 79-year-old male who has enjoyed a high level of physical activity, including ongoing participation in competitive rowing. In 2006, he presented with symptomatic typical right atrial flutter and underwent successful catheter ablation of the right atrial cavotricuspid isthmus. His outcome rhythm was sinus, but with asymptomatic second-degree and intermittent high-grade or complete heart block. Electrophysiologic testing confirmed block at the level of the atrioventricular (AV) node with normal infranodal conduction (His-ventricular [HV] interval 54 msec); it was presumed that AV block was physiologic due to his high level of physical conditioning, and improvement in AV conduction was demonstrated during exercise. Therefore, we felt pacemaker insertion was not indicated.

He remained asymptomatic until 2016 when he returned for evaluation of highly symptomatic, persistent atrial fibrillation, which limited his ability to exercise. After cardioversion, he was in sinus rhythm with complete heart block; therefore, it was felt that antiarrhythmic drug therapy could not be offered without backup pacing support. The patient opted to proceed to catheter ablation.

His first ablation for atrial fibrillation was performed in September 2018. He was in atrial fibrillation on presentation. All four pulmonary veins were isolated using radiofrequency ablation. In addition, mapping with the FIRMap and RhythmView Workstation (Abbott) was performed for 2 rotors in the right atrium at the lateral free wall and the posterior septum.

Atrial fibrillation recurred and the patient underwent cardioversion in February 2019. Atrial fibrillation recurred early after cardioversion and a second ablation was performed in March 2019. All 4 pulmonary veins were confirmed to be isolated. The FIRMap and RhythmView Workstation were again used to locate and ablate 2 rotors in the right atrium at the posterior septum and anterolateral free wall. One rotor was ablated between the left atrial appendage and the mitral valve annulus. An atrial tachycardia involving the left superior and inferior veins was treated with ablation anterior to the left pulmonary veins. A posterior wall ablation line was created between the left and right superior pulmonary veins.

Atrial fibrillation recurred again shortly after ablation. Monitoring showed that atrial fibrillation was now paroxysmal, and spontaneous conversion to sinus rhythm was associated with symptom relief. However, his atrial fibrillation later became persistent again, and cardioversion was performed once more in August 2019. A third ablation was then performed in January 2020; at this time, spontaneous atypical left atrial flutter was present, but mapping and ablation were unsuccessful. Subsequent ambulatory monitoring showed that atrial fibrillation continued to be paroxysmal, with symptoms confirmed to be associated with the arrhythmia.

Ultimately, we discussed additional treatment options such as pacemaker insertion and antiarrhythmic drug therapy, surgical Maze, and the Convergent procedure. Despite his multiple previous ablation procedures, we hoped that effective ablation of the posterior left atrial wall would eliminate atrial fibrillation and his multiple atrial tachycardias, as well as allow him to maintain sinus rhythm while avoiding the need for pacemaker insertion and long-term drug therapy. He opted to proceed with the Convergent procedure and, aware of our plans to develop this program at our institution, opted to be our first Convergent patient.

The Convergent procedure was performed in April 2021. The electroanatomic map was available from his previous (third) ablation attempt and showed extensive scarring of the left atrial anterior wall, with largely preserved voltage and islands of low voltage in the posterior wall (Figure 1).

This map can be compared with the endocardial voltage map obtained after the surgical portion of the Convergent procedure was performed, showing the previously confirmed pulmonary vein isolation, now with effective ablation and elimination of voltage in a homogenous pattern in the left atrial posterior wall (Figure 2).

During mapping, the patient developed a spontaneous left atrial tachycardia that was successfully mapped (Figure 3A; Video 1) and ablated with conversion to sinus rhythm (Figure 3B).

The patient made a rapid recovery following the Convergent procedure and was discharged on postoperative day 2. An echocardiogram on day 7 showed a small, asymptomatic pericardial effusion without evidence for tamponade. He remained asymptomatic and has remained in sinus rhythm since his most recent (6-month) follow-up visit.

Video 1

Video 1: Left atrial propagation map of the spontaneous left atrial tachycardia seen after the surgical portion of the Convergent procedure.

Developing a Convergent Program

In implementing the Convergent program at our institution, we had several goals in mind. We wanted to ensure that we provided a safe and effective procedure to improve the outcomes for ablation in our patients with symptomatic longstanding persistent atrial fibrillation, or as in the patient described above, patients who had previously undergone one or more ablation procedures for atrial fibrillation without successful control of their arrhythmia.

While the Convergent procedure can be performed in a staged manner, with the catheter portion being performed on the day following the surgical component or even several weeks later, we decided to perform both portions of the procedure on the same day to reduce the number of procedures and episodes of general anesthesia, and to provide the most convenient approach for our patients compared with multiple hospitalizations and procedures.

We decided to perform the Convergent procedure entirely in our electrophysiology laboratory, rather than performing the surgical component in our cardiac operating room (OR) and then transporting the patient to the EP lab for the catheter portion of the procedure. In doing so, we had the advantage of having already implemented our lead extraction program in the EP lab. As a result, our cardiac surgeons, nurses, scrub technicians, and perfusionists were already accustomed to supporting procedures in the EP lab. Also, the procedures for bringing the necessary surgical supplies and equipment to the EP lab had already been developed and were in regular use. In addition, our EP lab was evaluated to ensure that it met the necessary requirements for routine performance of an open chest surgical procedure.

We did consider using our hybrid OR for this procedure, but unfortunately, the heavy procedural volumes already taking place in that facility made the EP lab a more feasible location. We also found that it was simpler to bring the necessary surgical equipment from the operating room to the EP lab than to bring EP lab recording, mapping, and ablation equipment to the hybrid OR. Several “dry runs” were undertaken to ensure that the surgical equipment, including monitors for thoracoscopy, could be arranged in the EP lab to provide the surgeon with proper visualization and then removed from the EP lab to make room for the mapping and ablation equipment to be moved into place.

After reviewing the protocols and order sets that were kindly provided to us by several already established Convergent programs, we were able to develop our own protocols for preoperative assessment and postoperative management.

The result was a very smooth course for our first Convergent patients and for the patients who have undergone this procedure since then.

Conclusion

The Convergent procedure for combined surgical and catheter ablation for patients with longstanding persistent atrial fibrillation or unsuccessful rhythm control after prior catheter ablation can provide additional benefits compared with catheter ablation alone. With this hybrid approach, complete transmural ablation of the left atrial posterior wall is achieved safely with reduced risk of esophageal injury, leading to isolation of non-pulmonary vein triggers of recurrent atrial fibrillation. We have been able to successfully implement this procedure in our EP laboratory and provide a safe and effective procedure for our patients, including our first patient with highly symptomatic atrial fibrillation despite three prior catheter-based procedures. 

Disclosures: The authors have no conflicts of interest to report regarding the content herein.

Recommended Reading

1. Scherr D, Khairy P, Miyazaki S, et al. Five-year outcome of catheter ablation of persistent atrial fibrillation using termination of atrial fibrillation as a procedural endpoint. Circ Arrhythm Electrophysiol. 2015;8:18-24. Epub 2014 Dec 20. doi: 10.1161/CIRCEP.114.001943

2. Clarnette JA, Brooks AG, Mahajan R, et al. Outcomes of persistent and long-standing persistent atrial fibrillation ablation: a systematic review and meta-analysis. Europace. 2018;20(FI_3):f366-f376. doi: 10.1093/europace/eux297

3. 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:e009288. Epub 2020 Nov 13. doi: 10.1161/CIRCEP.120.009288