A Hybrid Maze Procedure for Long-Standing Persistent Atrial Fibrillation

Concurrent vs Staged Hybrid Ablation for Long-Standing Persistent Atrial Fibrillation: A Propensity-Matched Cohort Study

BACKGROUND

Long-term success rates of catheter ablation (CA) for long-standing persistent atrial fibrillation (LSPAF) are less than satisfactory. Further improvement of ablation methods is crucial for enhancing the treatment of LSPAF.

OBJECTIVES

This study sought to compare the outcomes of concurrent vs staged minimally invasive surgical-catheter hybrid ablation for LSPAF.

METHODS

From December 2015 to December 2021, 104 matched patients (concurrent and staged, 1:1) were included in study. In the concurrent group, both left unilateral thoracoscopic epicardial ablation (EA) and CA were performed simultaneously in one procedure. In the staged group, EA was performed at the first hospitalization. If the patients experienced atrial fibrillation (AF) recurrence, CA was performed between 3 months and 1 year after EA.

RESULTS

In the concurrent group, 4 patients were restored to sinus rhythm after EA, and 41 were patients restored to sinus rhythm during CA; 86.5% (45 of 52) achieved intraprocedural AF termination during concurrent hybrid ablation. In the staged group, all 52 patients underwent staged CA because of the recurrence of AF or atrial tachycardia (AT). Forty-seven (90.4%) patients achieved intraprocedural AF or AT termination during CA. Freedom from AF or AT off antiarrhythmic drugs at 2 years after hybrid ablation was 79.9% ± 5.7% in the concurrent group and 86.0% ± 4.9% in the staged group (P = 0.390). Failure of intraprocedural AF termination (HR: 14.378) was an independent risk factor for AF recurrence after hybrid ablation.

CONCLUSIONS

Both concurrent and staged hybrid ablation could be safely and effectively applied to treat LSPAF. Improving the intraprocedural AF termination rate predicted better outcomes.

Hybrid Totally Thoracoscopic Maze and Catheter Ablation for Persistent Atrial Fibrillation: Initial Experience

Atrial fibrillation is now a pandemic in our ageing community. Although James L. Cox devised a surgical procedure with near-universal curative success in 1987, catheter-based interventions have flourished. For persistent atrial fibrillation (AF), however, an isolated endocardial approach has limitations: procedural times are long, carry risk, and the outcomes are not durable. By combining left atrial endocardial and epicardial interventions with staged mapping, we optimise the benefits of both approaches. Our initial series of hybrid ablation for persistent atrial fibrillation reports excellent early outcomes, freedom from complications and excellent success at follow-up.

Short-term results of two strategies in thoracoscopic ablation for lone atrial fibrillation

Background: Thoracoscopic ablation is an effective treatment of patients with atrial fibrillation. Nowadays, 2 types of ablative devices are available in clinical practice allowing one to perform the thoracoscopic procedure Medtronic and AtriCure. However, the contemporary clinical literature does not have enough data that would compare these two approaches. Aims: to perform a comparative analysis of the short-term results of two minimally invasive strategies in thoracoscopic ablation for atrial fibrillation. Methods: 232 patients underwent thoracoscopic ablation for atrial fibrillation in two clinical centers for the period from 2016 to August 2021. The patients were divided into 2 groups. The first group was represented by those patients to whom a Medtronic device was applied (n=140), the second group was treated with an AtriCure device (n=92). The patients were comparable in their age, gender, initial severity of the condition. The follow-up consisted of laboratory tests, chest Х-ray, electrocardiography, 24-hour Holter monitor, echocardiography. The structure and prevalence of postoperative and intraoperative complications, specifics of the postoperative period were compared between the two groups. Results: According to the structure and prevalence of intraoperative complications the 2 groups are comparable to each other: 4.3% and 1.1% for the 1st group and 2nd group, respectively (p 0.05). The postoperative complications had developed in 6 (4.3%) and 5 (5.4%) patients in groups 1 and 2, respectively (p 0.05). At the time of discharge from hospital, a sinus rhythm was registered in 93.6% of patients (1st group), and 85.9% (2nd group) (p 0.05). Conclusions: Both strategies have demonstrated comparable short-term results in patients with lone atrial fibrillation. A further research is needed to evaluate the effectiveness of this strategy in a long-term period.

Box lesion or bi-atrial lesion set for atrial fibrillation during thoracoscopic epicardial ablation

OBJECTIVES

Thoracoscopic epicardial ablation with a limited lesion set led to suboptimal results for advanced paroxysmal atrial fibrillation (AF) or persistent AF. Whether additional right atrial lesions improve the result is unclear.

METHODS

We conducted a retrospective study involving 80 consecutive patients with paroxysmal or persistent AF, left atrial (LA) dilation (LA diameter >40 mm) and failed prior interventional ablation (40 patients, 50%) who underwent thoracoscopic epicardial ablation with box lesions (36 patients) or bi-atrial (BA) lesion (44 patients) in our institution. Freedom from atrial tachyarrhythmias after the procedures was compared between the box lesion group and BA lesion group.

RESULTS

Baseline differences included more patients with persistent AF (86.4% vs 47.2%) and larger left atrium [48.00 (44.00-50.75) vs 42.00 (41.25-44.00) mm] in the BA lesion group. There was no difference in procedural complications between the 2 groups. After a mean follow-up of 32 months, the freedom from atrial tachyarrhythmias off antiarrhythmic drugs at 6, 12 and 24 months was 77.2%, 77.2% and 77.2% in the BA lesion group and 69.4%, 50.0% and 40.6% in the box lesion group, respectively (P = 0.006). After adjustment for sex, age, body mass index, LA diameter, AF type, history of AF, and previous interventional ablation, BA lesion was an independent predictor of lower atrial tachyarrhythmia recurrence (hazard ratio 0.447, 95% confidential interval 0.208-0.963; P = 0.040).

CONCLUSIONS

Compared with the box lesion set, thoracoscopic epicardial ablation with BA lesion sets might provide better freedom from atrial tachyarrhythmias for paroxysmal or persistent AF with LA dilation. Randomized control trials are warranted to confirm the benefit of BA lesion sets in these patients.

Catheter, surgical, or hybrid procedure: what future for atrial fibrillation ablation?

BACKGROUND

The debate on the best treatment strategy for atrial fibrillation (AF) has expanded following the introduction of the so-called "hybrid procedure" that combines minimally invasive epicardial ablation with endocardial catheter ablation. However, the advantage of the hybrid approach over conventional epicardial ablation remains to be established.

METHODS

From June 2008 to December 2020, 609 surgical AF ablation procedures through a right minithoracotomy were performed at our institution. From 2008 to 2011, a unipolar radiofrequency (RF) device was used, whereas from 2011 to 2020 a bipolar RF device was used. In addition, between September 2016 and April 2017, 60 patients underwent endocardial completion of epicardial linear ablation. In 30 of these latter patients, surgical isolation of the Bachmann's bundle (BB) was also performed. Starting from 2021, surviving patients at follow-up were asked to undergo electrocardiographic evaluation and left ventricular function assessment and to complete a questionnaire addressing quality of life and predisposing factors for recurrent AF.

RESULTS

The ablation procedure was completed in all patients. Upon discharge, 30 (4.9%) patients showed recurrence of AF, whereas the remaining patients (95.1%) were in sinus rhythm. All patients in whom a hybrid approach was used either with or without BB ablation were discharged in sinus rhythm. After a mean follow-up of 74 months, 122 (20%) patients developed recurrent AF, including 19.9% in whom a unipolar RF device was used, 21% in whom a bipolar RF device was used, 23% who had undergone a hybrid procedure without BB ablation and 3.3% who had undergone a hybrid procedure with BB ablation. On multivariate analysis, reduced left ventricular ejection fraction, worsening of European Heart Rhythm Association symptom class, and cognitive impairment or depression during follow-up were found to be significantly associated with AF recurrence.

CONCLUSIONS

Surgical AF ablation through a right minithoracotomy is safe and may allow the creation of additional linear lesions, particularly in the BB. The placement of adjunctive linear lesions in the setting of a hybrid procedure can be more effective in reducing the risk for AF recurrence than isolated surgical ablation or hybrid ablation without the addition of further linear lesions, with no incremental risk to the patient.

Immediate electrophysiological characteristics following modified thoracoscopic ablation via unilateral approach for non-valvular atrial fibrillation

BACKGROUND

Thoracoscopic ablation has emerged as an effective therapy for patients with long-standing persistent Atrial fibrillation (LsPAF). We aimed to investigate the immediate electrophysiological characteristics following modified ablation with 3 circular and 3 linear lesions in the thoracoscopic procedure via a unilateral approach.

METHODS

Between May 2015 and October 2018, 40 patients underwent the one-stage hybrid procedure for LsPAF. Isolation of the pulmonary veins (PV) and left atrium posterior wall (LAPW), excision of the left atrial appendage (LAA), and high-density endocardial mapping and individualized percutaneous catheter ablation for AF termination were performed.

RESULTS

The modified thoracoscopic procedure may enable successful PV and LAPW isolation and LAA removal. Endocardial electrophysiological examination showed 6 out of 40 (15%) patients with a right PV gap, 3 (7.5%) patients with incomplete roof lesions, and 8 (20%) patients with incomplete Dallas lesions. A total of 44 driving areas were mapped and ablated. Thirty-five patients achieved procedural AF termination. After a mean follow-up period of 26 months, the success rate of a single procedure was 85%. Cox regression analysis demonstrated that the failure of procedural AF termination may be a risk factor in atrial tachyarrhythmia recurrence.

DISCUSSION

Endocardial electrophysiological examination is a necessary partner to thoracoscopic ablation. Our modified thoracoscopic ablation and driving areas-based ablation contribute to high rates of procedural AF termination, which may lead to reduced recurrence rate. The hybrid procedure may be an effective strategy for the management of LsPAF.

Targeting Bachmann's bundle in hybrid ablation for long-standing persistent atrial fibrillation: a proof of concept study

BACKGROUND

Catheter-based or surgical procedures in patients with long-standing persistent atrial fibrillation (LSPAF) remain a challenge. As a result, different approaches including hybrid (surgical and endocardial) ablation have been developed. Bachmann's bundle (BB) is a mainly epicardial structure capable of sustaining arrhythmic reentry that could be involved in the development and perpetuation of atrial fibrillation. We investigated the efficacy and safety of an adjunctive BB ablation in LSPAF patients undergoing hybrid ablation.

METHODS

In a two-arm non-randomized study, consecutive LSPAF patients undergoing epicardial isolation of pulmonary veins with left atrial posterior wall (box lesion) with (n = 30, BB group) and without additional BB ablation (n = 30, CONV group) were enrolled in the study. All patients underwent an endocardial procedure within 6 weeks post-surgery to assess for potential lesion gaps and additional atrial substrate modification. The primary endpoint was freedom from AF through 12 months of follow-up.

RESULTS

The two-staged hybrid ablation was successfully completed in all patients. One-year freedom from atrial arrhythmias recurrence rates was 96.6% in the BB group vs 76.6% in the CONV group (p = 0.025). At procedure completion, 30 (100%) and 17 (56%) patients had a spontaneous cardioversion in BB and CONV group, respectively (p < 0.001). No significant differences in quality of life or complication rates were observed.

CONCLUSIONS

This initial experience shows, for the first time, that adjunctive BB ablation in the setting of hybrid ablation for LSPAF is a feasible and effective approach in increasing maintenance of sinus rhythm without increasing complication rates.

Comprehensive evaluation of electrophysiological and 3D structural features of human atrial myocardium with insights on atrial fibrillation maintenance mechanisms

Atrial fibrillation (AF) occurrence and maintenance is associated with progressive remodeling of electrophysiological (repolarization and conduction) and 3D structural (fibrosis, fiber orientations, and wall thickness) features of the human atria. Significant diversity in AF etiology leads to heterogeneous arrhythmogenic electrophysiological and structural substrates within the 3D structure of the human atria. Since current clinical methods have yet to fully resolve the patient-specific arrhythmogenic substrates, mechanism-based AF treatments remain underdeveloped. Here, we review current knowledge from in-vivo, ex-vivo, and in-vitro human heart studies, and discuss how these studies may provide new insights on the synergy of atrial electrophysiological and 3D structural features in AF maintenance. In-vitro studies on surgically acquired human atrial samples provide a great opportunity to study a wide spectrum of AF pathology, including functional changes in single-cell action potentials, ion channels, and gene/protein expression. However, limited size of the samples prevents evaluation of heterogeneous AF substrates and reentrant mechanisms. In contrast, coronary-perfused ex-vivo human hearts can be studied with state-of-the-art functional and structural technologies, such as high-resolution near-infrared optical mapping and contrast-enhanced MRI. These imaging modalities can resolve atrial arrhythmogenic substrates and their role in reentrant mechanisms maintaining AF and validate clinical approaches. Nonetheless, longitudinal studies are not feasible in explanted human hearts. As no approach is perfect, we suggest that combining the strengths of direct human atrial studies with high fidelity approaches available in the laboratory and in realistic patient-specific computer models would elucidate deeper knowledge of AF mechanisms. We propose that a comprehensive translational pipeline from ex-vivo human heart studies to longitudinal clinically relevant AF animal studies and finally to clinical trials is necessary to identify patient-specific arrhythmogenic substrates and develop novel AF treatments.

Contemporary Surgical Management of Atrial Fibrillation

Atrial fibrillation is a common arrhythmia which may cause symptoms that significantly impact quality of life and is associated with increased risk of stroke, heart failure, and sudden death. Over the past three decades many surgical techniques as well as catheter-bases procedures have been developed to treat atrial fibrillation. In this review we describe the indications, treatments, outcomes, surgical techniques, and technical advances reported in the literature.

Atrial fibrillation: Current and emerging surgical strategies

OBJECTIVE

(a) To provide a comprehensive review of current literature on the surgical management of atrial fibrillation (AF), highlighting surgical approaches and outcomes. (b) To summarize the latest guidelines pertinent to the surgical management of AF.

BACKGROUND

AF is associated with high rates of morbidity and mortality, primarily related to the associated risk of stroke. The mainstay of management is pharmacologic rate or rhythm control and catheter-based ablation. Surgical ablation (SA) is an alternative strategy that is effective in select patient populations. Recently, novel techniques and technologies have been introduced and this has expanded the surgical capacity to manage AF.

METHODS

A comprehensive review of the literature was conducted.

RESULTS

Surgery can be a highly effective alternative therapeutic option for the management of AF in the appropriate patient population. The need for permanent pacemaker implantation is controversial among patients undergoing surgical intervention for AF. Surgical outcomes are promising, with long-term control of AF and symptomatic relief achieved in select groups of patients.

CONCLUSIONS

This article provides a comprehensive review of the surgical management of AF. We have summarized the latest surgical outcomes and contextualized the most recent guidelines.

Comparison of Cryoballoon and Hybrid surgical Posterior Wall Isolation for Persistent Atrial Fibrillation to conventional ablation

Background

Optimalablation strategy for persistent atrial fibrillation (AF) is unclear;PWI of the left atrium may improve outcome.Our aim was to compare outcomes of posterior wall isolation (PWI) ablation for persistent AF achieved by cryoballoon ablation (CRYO) or hybrid surgical ablation (HABL) to matched patients undergoing conventional radiofrequency ablation (CRA).

Methods

In our single center retrospective study,patients underwent HABL and CRYO withcircumferential pulmonary vein ablation (CPVA),roof and floor lines to complete PW box lesion. CRA consisted of CPVA, roof line and lateral mitral isthmus line (MVI).

Results

Of 61 patients (mean duration of AF 1.3 ± 0.4 yrs)who underwent ablation, after follow-up of 366 ± 62 days, AF recurrence was 10.5% and 48% (p=0.001) and the need for repeat ablation 5% vs 30% (p=0.007) in PWI and CRA groups respectively, without a significant difference in incidence of AT/FL 18 vs 26 % or cardioversion 5.2 vs 7.1 %. Total procedure time and fluoroscopic time were 242 ±70 min vs 279 ±53 min (p=0.08) and 20±9 min vs 12 ± 4 min (p=0.003) for PWI and CRA respectively. CRYO had less AF recurrence and complications than HABL. Mean length of stayfor CRYO patients was 41 hrs compared to 145 hrs in HABL group, who underwent two procedures.

Conclusion

PWI in persistent AF patients decreases recurrence of AF and need for repeat procedure compared to CRA; PWI by CRYO is superior to HABL due to less LOS and complications.

The role of personalized atrial modeling in understanding atrial fibrillation mechanisms and improving treatment

Atrial fibrillation is the most common arrhythmia in humans and is associated with high morbidity, mortality and health-related expenses. Computational approaches have been increasingly utilized in atrial electrophysiology. In this review we summarize the recent advancements in atrial fibrillation modeling at the organ scale. Multi-scale atrial models now incorporate high level detail of atrial anatomy, tissue ultrastructure and fibrosis distribution. We provide the state-of-the art methodologies in developing personalized atrial fibrillation models with realistic geometry and tissue properties. We then focus on the use of multi-scale atrial models to gain mechanistic insights in AF. Simulations using atrial models have provided important insight in the mechanisms underlying AF, showing the importance of the atrial fibrotic substrate and altered atrial electrophysiology in initiation and maintenance of AF. Last, we summarize the translational evidence that supports incorporation of computational modeling in clinical practice for development of personalized treatment strategies for patients with AF. In early-stages clinical studies, AF models successfully identify patients where pulmonary vein isolation alone is not adequate for treatment of AF and suggest novel targets for ablation. We conclude with a summary of the future developments envisioned for the field of atrial computational electrophysiology.