Current role of atrioventricular junction (AVJ) ablation

Atrioventricular Nodal Ablation and Pacing in Refractory Atrial Fibrillation and Heart Failure

Atrioventricular nodal ablation (AVNA) represents a critical intervention in the management of refractory atrial fibrillation (AF) and heart failure (HF). When combined with biventricular pacing or conduction system pacing, particularly His bundle pacing and left bundle branch area pacing, this strategy offers distinct and complementary benefits. While each pacing modality presents unique advantages and potential limitations, their combination with AVNA offers a comprehensive and individualized treatment strategy for addressing associated HF. This integrated approach can enhance symptom control, improve hemodynamic performance, and contribute to better long-term outcomes in patients with advanced HF and AF.

Low-Power Long-Duration Versus High-Power Short-Duration Radiofrequency Ablation of the Atrioventricular Node

BACKGROUND

Atrioventricular node (AVN) radiofrequency (RF) ablation is a highly effective treatment of atrial tachyarrhythmias that are resistant to other management modalities. To date, there is limited research that compares the properties of different RF ablation catheters. The current study aims to compare the effectiveness of several types of RF catheters in AVN ablation.

METHODS

A total of 66 patients, with a mean age of 73.27 years, underwent AVN RF ablation. The catheters used were categorized as unirrigated (UI), externally irrigated, and contact force sensing with 10 to 20 g of force. Externally-irrigated catheters were divided into 2 different settings: low-power long-duration (LPLD) (30 W, 45°C, and 60 seconds) and high-power short-duration (HPSD) (50 W, 43°C, and 12 seconds). We compared the success rate of the different RF catheters using logistic regression and lesion times using linear regression.

RESULTS

The distribution of the types of catheters used is UI in 48%, LPLD in 16%, and HPSD in 36% of patients. All ablation procedures were successful, with no immediate postprocedure complications. HPSD had a significantly shorter lesion time than UI catheters by 403.42 seconds (-631.67 to -175.17).

CONCLUSIONS

UI catheters, LPLD, and HPSD were equally safe and effective in ablation procedures. The HPSD catheter had a significantly shorter lesion time and, thus, overall decreased procedure time.

Comparison of His-Purkinje Conduction System Pacing with Atrial-Ventricular Node Ablation and Pharmacotherapy in HFpEF Patients with Recurrent Persistent Atrial Fibrillation (HPP-AF study)

BACKGROUND

There is currently no particularly effective strategy for patients with persistent atrial fibrillation accompanying heart failure with preserved ejection fraction (HFpEF), especially with recurrent atrial fibrillation after ablation. In this study, we will evaluate a new treatment strategy for patients with persistent atrial fibrillation who had at least two attempts (≧2 times) of radio-frequency catheter ablation but experienced recurrence, and physiologic conduction was reconstructed after atrioventricular node ablation or drug therapy, to control the patient's ventricular rate to maintain a regular heart rhythm, which is called His-Purkinje conduction system pacing (HPCSP) with atrioventricular node ablation.

METHODS AND RESULTS

This investigator-initiated, multicenter prospective randomized controlled trial aimed to recruit 296 randomized HFpEF patients with recurrent atrial fibrillation. All the enrolled patients were randomly assigned to the pacing group or the drug treatment group. The primary endpoint is differences in cardiovascular events and clinical composite endpoints (all-cause mortality) between patients in the HPCSP and drug-treated groups. Secondary endpoints included heart failure hospitalization, exercise capacity assessed by cardiopulmonary exercise tests, quality of life, echocardiogram parameters, 6-minute walk distance, NT-ProBNP, daily patient activity levels, and heart failure management report recorded by the CIED. It is planned to compete recruitment by the end of 2023 and report in 2025.

CONCLUSIONS

The study aims to determine whether His-Purkinje conduction system pacing with atrioventricular node ablation can better improve patients' symptoms and quality of life, postpone the progression of heart failure, and reduce the rate of rehospitalization and mortality of patients with heart failure.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR1900027723, URL: http://www.chictr.org.cn/edit.aspx?pid=46128&htm=4.

Leadless pacemaker implant with concomitant atrioventricular node ablation: Experience with the Micra transcatheter pacemaker

Background

The feasibility and outcomes of concomitant atrioventricular node ablation (AVNA) and leadless pacemaker implant are not well studied. We report outcomes in patients undergoing Micra implant with concomitant AVNA.

Methods

Patients undergoing AVNA at the time of Micra implant from the Micra Transcatheter Pacing (IDE) Study, Continued Access (CA) study, and Post‐Approval Registry (PAR) were included in the analysis and compared to Micra patients without AVNA. Baseline characteristics, acute and follow‐up outcomes, and electrical performance were compared between patients with and without AVNA during the follow‐up period.

Results

A total of 192 patients (mean age 77.4 ± 8.9 years, 72% female) underwent AVNA at the time of Micra implant and were followed for 20.4 ± 15.6 months. AVNA patients were older, more frequently female, and tended to have more co‐morbid conditions compared with non‐AVNA patients (N = 2616). Implant was successful in 191 of 192 patients (99.5%). The mean pacing threshold at implant was 0.58 ± 0.35 V and remained stable during follow‐up. Major complications within 30 days occurred more frequently in AVNA patients than non‐AVNA patients (7.3% vs. 2.0%, p < .001). The risk of major complications through 36‐months was higher in AVNA patients (hazard ratio: 3.81, 95% confidence interval: 2.33–6.23, p < .001). Intermittent loss of capture occurred in three AVNA patients (1.6%), all were within 30 days of implant and required system revision. There were no device macrodislodgements or unexpected device malfunctions.

Conclusion

Concomitant AVN ablation and leadless pacemaker implant is feasible. Pacing thresholds are stable over time. However, patient comorbidities and the risk of major complications are higher in patients undergoing AVNA.

Safety and Efficacy Outcomes of Combined Leadless Pacemaker and Atrioventricular Nodal Ablation for Atrial Fibrillation Using a Single Femoral Puncture Approach

BACKGROUND

Atrioventricular nodal (AVN) ablation with permanent pacemaker (PPM) insertion is indicated for rate control in patients with atrial fibrillation (AF) who remain unresponsive to rate or rhythm control strategies. The leadless PPM (Micra Transcatheter Pacing System [TPS], Medtronic, Minneapolis, MN, USA) has the advantage of eliminating transvenous lead and pacemaker pocket-related complications. The aim of this case series was to determine the outcomes of patients who had undergone combined Micra TPS and AVN ablation, performed via a single femoral approach.

METHOD

A retrospective review was undertaken on patients who had undergone concurrent procedures, across two major hospitals in Perth, Western Australia. Procedural details were obtained from a cardiac devices database whilst patient demographics and clinical information were determined from medical records.

RESULTS

Fourteen (14) patients underwent concurrent Micra TPS insertion and AVN ablation for symptomatic AF. The average age was 73±9.2 years, and 43% of them were males. There was no acute procedural/device related complication. Over a median follow-up duration of 9 months (36% completing 12-month follow-up), there was no incidence of device complications, in particular device dislodgement, malfunction or infection. One patient had a resuscitated ventricular fibrillation (VF) arrest event with new onset cardiomyopathy during follow-up and required Micra TPS removal. One patient died at 33 days post procedure from a non-cardiac cause. Device performance was excellent with stable sensing and pacing thresholds during the follow-up period.

CONCLUSION

Our study has shown that combined leadless PPM (Micra TPS) implantation and AVN ablation using a single femoral approach is feasible, with good safety and efficacy profile in the short-medium term. Long-term data involving larger cohorts is needed to confirm the findings of this study and determine the clinical usefulness of this combined approach.

Acute and long-term outcomes of simultaneous atrioventricular node ablation and leadless pacemaker implantation

AIMS

Leadless pacemaker (LDP) allows implantation using a femoral approach. This access could be utilized for conventional atrioventricular nodal ablation (AVNA). It could facilitate unifying the two procedural components. Data regarding its feasibility and long-term outcomes remain lacking. We aim to evaluate the feasibility and long-term outcomes of sequential LDP and AVNA.

METHODS

Prospective, observational multicenter study including consecutive patients with indication for single-chamber pacemaker placement. In those with additional indication for AVNA, ablation was performed immediately after the LPD through the same sheath.

RESULTS

A total of 137 patients were included. Mean age was 77.9 ± 10.5 years; 74 (54%) were men. Immediately following LDP implantation, 27 patients (19.7%) underwent concurrent AVNA. There were six (5.5%) complications in patients referred for LDP procedures and three (11%) in those who underwent a combined approach. None of these complications were solely attributable to the added AVNA component. No mechanical dislodgement, electrical damage to any device, or electromagnetic interference ever took place. During a mean follow-up period of 123 ± 48 days, three patients (3.6%) died of noncardiovascular causes. The remaining population stayed alive without significant arrhythmias. There were no relevant differences with regard to sensing and pacing thresholds between patients in the two groups.

CONCLUSIONS

AVNA can safely be performed immediately following LDP. A combined approach obviates the need for additional vascular access and optimizes feasibility and comfort for patients and healthcare providers. It offers an acceptable safety and efficacy profile, both acutely and upon intermediate-term follow-up.

Atrioventricular Junction Ablation for Atrial Fibrillation

Atrioventricular junction (AVJ) ablation is an effective therapy in patients with symptomatic atrial fibrillation who are intolerant to or unsuccessfully managed with rhythm control or medical rate control strategies. A drawback is that the procedure mandates a pacing system. Overall, the safety and efficacy of AVJ ablation is high with a majority of the patients reporting significant improvement in symptoms and quality-of-life measures. Risk of sudden cardiac death after device implantation is low, especially with an appropriate postprocedure pacing rate. Mortality benefit with AVJ ablation has been shown in patients with heart failure and cardiac resynchronization therapy devices.

Atrioventricular Junction Ablation In Atrial Fibrillation: Choosing The Right Patient And Pacing Device

Atrial fibrillation (AF) is the most common cardiac arrhythmia and despite advancements in rhythm control through direct catheter ablation, maintaining sinus rhythm is not possible in a large proportion of AF patients, who therefore are subject to a rate control strategy only. Nonetheless, in some of these patients pharmacological rate control may be ineffective, often leaving the patient highly symptomatic and at risk of developing tachycardia-induced cardiomyopathy and heart failure (HF). Catheter ablation of the atrioventricular junction (AVJ) with subsequent permanent pacemaker implantation provides definite rate control and represents an attractive therapeutic option when pharmacological rate control is not achieved. In patients with reduced ventricular function, cardiac resynchronization therapy (CRT) should be considered over right ventricular apical (RVA) pacing in order to avoid the deleterious effects associated with a high amount of chronic RVA pacing. Another group of patients that may also benefit from AVJ ablation are HF patients with concomitant AF receiving CRT. In this patient cohort AVJ ablation ensures near 100% biventricular pacing, thus allowing optimization of the therapeutic effects of CRT.

Hybrid therapy in the management of atrial fibrillation

Atrial fibrillation is the most common sustained arrhythmia. Because of the sub-optimal outcomes and associated risks of medical therapy as well as the recent advances in non-pharmacologic strategies, a multitude of combined (hybrid) algorithms have been introduced that improve efficacy of standalone therapies while maintaining a high safety profile. Antiarrhythmic administration enhances success rate of electrical cardioversion. Catheter ablation of antiarrhythmic drug-induced typical atrial flutter may prevent recurrent atrial fibrillation. Through simple ablation in the right atrium, suppression of atrial fibrillation may be achieved in patients with previously ineffective antiarrhythmic therapy. Efficacy of complex catheter ablation in the left atrium is improved with antiarrhythmic drugs. Catheter ablation followed by permanent pacemaker implantation is an effective and safe treatment option for selected patients. Additional strategies include pacing therapies such as atrial pacing with permanent pacemakers, preventive pacing algorithms, and/or implantable dual-chamber defibrillators are available. Modern hybrid strategies combining both epicardial and endocardial approaches in order to create a complex set of radiofrequency lesions in the left atrium have demonstrated a high rate of success and warrant further research. Hybrid therapy for atrial fibrillation reviews history of development of non-pharmacological treatment strategies and outlines avenues of ongoing research in this field.

Comparison of different approaches to atrioventricular junction ablation and pacemaker implantation in patients with atrial fibrillation

BACKGROUND

To compare the feasibility and efficiency of atrioventricular junction (AVJ) ablation and device implantation in patients with drug-refractory atrial fibrillation using three different approaches.

METHODS

Sixty-nine patients (57% male; age 72 ± 10; ejection fraction 45 ± 15%) undergoing device implantation and AVJ ablation were retrospectively studied at a tertiary referral center. In 20 patients (29%) AVJ ablation was performed via the femoral vein immediately following device implantation (group 1), whereas 33 patients (48%) underwent a staged procedure with AVJ ablation via the femoral vein >3 weeks after device implantation (group 2). In a third group of 16 patients (23%), AVJ ablation was performed during device implantation through the pocket using the same axillary vein access site (group 3). The main outcome measures were: procedure time, fluoroscopy time, laboratory occupancy time, and success rate.

RESULTS

There was a significant difference in procedure time (118 ± 45 minutes. in group 1, 133 ± 32 minutes in group 2, and 87 ± 26 minutes in group 3, P < 0.001) and the laboratory occupancy time (175 ± 48 minutes in group 1, 200 ± 32 minutes in group 2, and 121 ± 27 minutes in group 3, P < 0.001). There was no difference in fluoroscopy time (group 1: 20 ± 15 minutes, group 2: 27 ± 22 minutes, and group 3: 24 ± 9 minutes P = 0.4). The procedure was successfully completed in all patients, but cross-over to a femoral approach was required in one patient in group 3.

CONCLUSION

The alternative approach of AVJ ablation during permanent pacemaker implantation from the same axillary vein access site is feasible and more efficient compared to the femoral approach.

Atrial fibrillation in heart failure in the older population

Atrial fibrillation (AF) is an important and often-underrecognized cause of cardiovascular morbidity and mortality. It is an arrhythmia that is commonly seen in the older patient; the median age of patients with AF in early studies was 75 years. Heart failure (HF) is also more frequently seen in the older patient with an approximate doubling of HF prevalence with each decade of life. There is clear interaction between AF and HF, with evidence that HF can lead to AF and AF exacerbates HF. This review focuses on the specific aspect of AF management in elderly patients with HF.