Midterm outcomes of two-staged hybrid ablation of persistent and long-standing persistent atrial fibrillation using the versapolar epicardial surgical device and subsequent catheter ablation

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.

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.

Ablation Modalities for Therapeutic Intervention in Arrhythmia-Related Cardiovascular Disease: Focus on Electroporation

Targeted cellular ablation is being increasingly used in the treatment of arrhythmias and structural heart disease. Catheter-based ablation for atrial fibrillation (AF) is considered a safe and effective approach for patients who are medication refractory. Electroporation (EPo) employs electrical energy to disrupt cell membranes which has a minimally thermal effect. The nanopores that arise from EPo can be temporary or permanent. Reversible electroporation is transitory in nature and cell viability is maintained, whereas irreversible electroporation causes permanent pore formation, leading to loss of cellular homeostasis and cell death. Several studies report that EPo displays a degree of specificity in terms of the lethal threshold required to induce cell death in different tissues. However, significantly more research is required to scope the profile of EPo thresholds for specific cell types within complex tissues. Irreversible electroporation (IRE) as an ablative approach appears to overcome the significant negative effects associated with thermal based techniques, particularly collateral damage to surrounding structures. With further fine-tuning of parameters and longer and larger clinical trials, EPo may lead the way of adapting a safer and efficient ablation modality for the treatment of persistent AF.

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.

Invasive therapies for patients with concomitant heart failure and atrial fibrillation

Atrial fibrillation (AF) and heart failure (HF) are two clinical entities that can present either separately or concurrently. One entity can lead to the other and vice versa as AF can not only be the underlying etiology of HF but also exacerbate HF due to other cardiac diseases. Besides prevention of cerebral and systemic embolism and elimination of AF-related symptoms, restoration of sinus rhythm for AF patients helps to avoid or reduce HF, irrespective of their underlying heart disease. Successful rates of medical therapy for AF are low in persistent AF, and much lower in long-standing AF, while invasive procedures for AF yield promising results. In this review, the authors evaluate the value of invasive therapies for HF patients complicated with non-valvular AF. We examine this clinical problem by interpreting the relationships between these two entities: the mechanism of tachycardia-induced cardiomyopathy (TIC), past opinions about rhythm control and rate control of AF, discrimination of HF-related AF and AF-induced HF, how to identify the AF patients that could benefit from invasive therapies, and how to select invasive therapies for different AF patients and peri-operative treatments.