Pacing of Left Bundle Branch Area and Atroventricular Node ablatIon in Patients With Symptomatic Atrial Fibrillation

Overview

This study aimed to compare the clinical outcomes of left bundle branch area pacing combined with atrioventricular node ablation and pharmacologic treatment optimized according to guidelines in patients with symptomatic atrial fibrillation refractory or intolerant to drug therapy or catheter ablation.

Detailed description

* Multicenter, randomized, open-label clinical trial * Randomization 1:1 fashion A randomly permuted-block randomization list was generated by computer at a central location and was stratified by center. * Study duration:

1. 6 months (for primary outcome) 2. 24 months (for secondary outcomes) * Study subjects number: 50 patients (25 patients per group) * Procedures

* Atrioventricular node ablation after successful left bundle branch area pacing at the same procedure time. * Left bundle branch area pacing will be performed in all patients (using lumenless or stylet-driven lead, on the operator's discretion) * Atrioventricular node ablation will be performed using the quadripolar 7-Fr 3.5-mm tip ablation catheter and the use of 8.5-F sheath (SR0 or SL1, St. Jude Medical Inc., St. Paul, MN, USA) depending on the operator's experience, and if not stable or failed, a deflectable sheath (Agilis, Abbott Electrophysiology, Menlo Park, CA, USA) will be used. Repeated ablation procedures will be recommended during follow-up if regression of atrioventricular block has occurred. * Immediately after implant, devices were programmed to achieve the shortest QRS duration. Unipolar pacing was initially used to determine left bundle branch capture.

Interventions

• Procedure Pacemaker implantation with Left bundle branch area pacing (LBBAP)
  Left bundle branch pacing is a novel pacing modality that can bypass the pathological or disease-vulnerable region in the cardiac conduction system, to provide physiological pacing modality for patients. The procedure involves the implantation of a permanent pacemaker with a pacing lead positioned at the left bundle branch area to achieve physiological conduction system pacing. LBBAP-Pacemaker device and leads should be implanted according to the physician's standard practice.
• Procedure Atrioventricular node ablation (AVNA)
  Atrioventricular node ablation uses heat energy, called radiofrequency energy, to destroy the area between the upper and lower heart chambers. This area is called the atrioventricular node.
• Drug Pharmacologic therapy optimized for Atrial Fibrillation management
  Pharmacologic therapy includes rate control with beta-blockers (e.g., bisoprolol), calcium channel blockers (e.g., diltiazem), or antiarrhythmic drugs (e.g., flecainide, propafenone, dronedarone, amiodarone) along with anticoagulation therapy (e.g., apixaban) as per current clinical guidelines (e.g., ESC 2024 or ACC/AHA/HRS 2023) in patients with permanent atrial fibrillation refractory or intolerant to drug therapy or catheter ablation. Treatment is tailored based on patient tolerance and clin

Primary outcome measures

• Change in NT-proBNP concentration (pg/ml) from baseline to 6-month follow-up [Time frame: 6 months after intervention.]

Secondary outcome measures (12)

• Change in NT-proBNP concentration (pg/ml) at 12, and 24 months [Time frame: 12 months and 24 months after intervention.]
• Change in health-related quality of life measured by 36-item short form survey (SF-36) questionnaire at 6, 12, 24 months [Time frame: 6, 12 and 24 months after intervention.]
• Change in health-related quality of life measured by EuroQol 5-Dimension Questionnaire (EQ-5D) at 6, 12, 24 months [Time frame: 6, 12 and 24 months after intervention.]
• Change in left ventricular ejection fraction (LV-EF, %) at 6, 12, and 24 months [Time frame: 6, 12 and 24 months after intervention]
• Change in left ventricular end-diastolic diameter (LVEDD, mm) at 6, 12, and 24 months [Time frame: 6, 12 and 24 months after intervention.]
• Change in left ventricular end systolic diameter (LVESD, mm) at 6, 12, and 24 months [Time frame: 6, 12 and 24 months after intervention.]
• Change in New York Heart Association (NYHA) functional class at 6, 12, and 24 months [Time frame: 6, 12 and 24 months after intervention.]
• Change in 6 min walk test at 6, 12, and 24 months [Time frame: 6, 12, and 24 months after intervention]
• Change in cognitive function measured by Montreal Cognitive Assessment (MoCA) score at 6, 12, and 24 months [Time frame: 6, 12 and 24 months after intervention.]
• Procedure-related complications (tamponade, device infection, re-intervention, pneumothorax, vascular complications, others) [Time frame: 24 months after intervention.]
• The all-cause mortality at 24 months [Time frame: 24 months after intervention.]
• Worsening Heart Failure (HF) at 24 Months [Time frame: 24 months after intervention.]

Eligibility criteria

Inclusion:

Patients who meet all of the following inclusion criteria 1)-6).

• Permanent atrial fibrillation
• Age ≥ 65 years
• Refractory or intolerant to antiarrhythmic drugs, rate control medications, or catheter ablation
• New York Heart Association (NYHA) functional class II- IV
• LVEF > 40% (within the past 3 months)
• Patients with at least one of the following:

• HF hospitalization (defined as HF as the major reason for hospitalization or treatment for HF lasting ≥12 hours and including treatment with intravenous (IV) diuretics at a healthcare facility) within 12 months
• Elevated NT-proBNP (>900 pg/ml) in the 30 days prior to enrollment

Exclusion:

Patients who meet at least one of the following exclusion criteria 1)-11).

• Asymptomatic atrial fibrillation
• Life expectancy to < 12 months.
• Primary moderate to severe valvular disease (except for functional mitral valve regurgitation or tricuspid valve regurgitation)
• Mechanical tricuspid valve replacement
• Severe chronic kidney disease (estimated Glomerular Filtration Rate ≤ 15 ml/1,73 m2 or receiving renal replacement treatment including hemodialysis or peritoneal dialysis)
• Obstructive hypertrophic cardiomyopathy
• Infiltrative cardiomyopathy (amyloidosis, sarcoidosis, Fabry disease, others)
• Acute coronary syndrome or coronary revascularization (CABG or PCI) <3 months
• Severe primary pulmonary disease such as cor pulmonale, irreversible lung disease requiring inhalers, oxygen supplementation
• Pacemaker/ICD/CRT treatment ongoing, or current pacemaker indication
• Simultaneous participation in a different randomized clinical trial

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

South Korea · 1 center

• Seoul National University Hospital — Seoul

Identifiers

NCT: NCT06699342 · PALLIATE-AF

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗