Electrically Guided Bachmann's Bundle Pacing: A Lead Placement Strategy With Potential Antiarrhythmic Benefits

Study Overview
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Brief Summary
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Despite identification of optimal ventricular pacing sites, which not only avoid dyssynchronous activation but can restore ventricular synchrony, optimal atrial pacing sites have not yet been identified. Specialized conduction tracts do not exist in the atria as they do in the ventricle. Activating the atria in a manner that preserves or improves interatrial synchrony may provide clinical benefit based on recent data. Prior site-selective right atrial septal pacing (RAS) pacing studies relied on non-specific fluoroscopic guidance during lead placement. These studies were limited by the lack of an electrogram target and electrical measures of successful atrial resynchronization. The goal of this study is to prospectively evaluate Bachmann's bundle lead placement guided by fluoroscopy and electrical markers (an endocardial electrogram target and paced P-wave criteria) and determine its anti-arrhythmic efficacy compared with right atrial appendage (RAA) pacing. Patients presenting for pacemaker placement with an indication for an atrial lead are randomized to either electrically-guided BB lead placement or RAA lead placement and then followed for 15 months.

Official Title
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Electrically Guided Bachmann's Bundle Pacing Pilot Study: A Novel Lead Placement Strategy With Potential Antiarrhythmic Benefits

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Procedure: Bachmann's bundle lead placement
* Procedure: Right atrial appendage lead placement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject is >18 years old Subject is referred for permanent pacemaker implantation with an indication for an atrial lead Subject has either paroxysmal atrial fibrillation or baseline intra-atrial conduction delay (P-wave duration >120ms on a 12-lead ECG) Subject is expected to remain available for standard-of-care pacemaker follow-up visits and study questionnaires Exclusion Criteria: Subject has permanent atrial fibrillation or is in atrial fibrillation in the pre-operative area prior to the procedure (inability to assess paced P-wave morphology) Subject has pacemaker implantation prior to planned atrioventricular nodal ablation Subject has resting spontaneous sinus rate >85 beats-per-minute Subject has left ventricular ejection fraction <45% Subject is unable or unwilling to complete baseline or follow up quality of life questionnaires Subject is currently enrolled in a potentially confounding trial Subject is pregnant Subject's anticipated life expectancy is less than 1 year

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Bachmann's bundle area pacing<br>Lead placement in Bachmann's bundle area | Procedure: Bachmann's bundle lead placement<br>* Atrial lead placement at Bachmann's bundle area<br>|
| Active Comparator: Right atrial appendage pacing<br>Lead placement in the right atrial appendage | Procedure: Right atrial appendage lead placement<br>* Atrial lead placement in the right atrial appendage<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Atrial arrhythmia burden from pacemaker counters | Derived from pacemaker counters and expressed as the average percentage of time per day in atrial fibrillation/tachycardia. | Over 15 month follow up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in P-wave duration from sinus P-wave to paced P-wave in Bachmann's bundle and right atrial appendage lead groups |  | At implant | 
| Atrial lead procedure time |  | At implant | 
| Atrial lead fluoroscopy time |  | At implant | 
| Atrial lead complications |  | Over 15 month follow up | 
| Atrial lead capture threshold (Volts) |  | Over 15 month follow up | 
| Atrial lead sensing threshold (millivolts) |  | Over 15 month follow up | 
| Atrial lead impedance threshold (Ohms) |  | Over 15 month follow up | 
| Atrial Fibrillation Severity Scale Version 2.0 | Change in quality of life. The Atrial Fibrillation Severity Scale (AFSS) is composed of 19 items investigating four domains: AF burden (comprised of AF frequency + AF duration + AF severity): score range is 3-10, higher score = greater burden Health care utilization: score range is 0-7 for each question, higher score = more utilization Symptoms: score range is 0-35, higher score = greater symptom severity Global well-being: score range is 1-10, higher score = better quality of life | Over 15 month follow up | 
| EQ-5D-3L survey (*EQ-5D-3L is the name of the instrument and is not an acronym) | Change in quality of life. The EQ-5D-3L is a standardized instrument to assess generic health-related quality of life and contains questions on five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. For each of the five dimension, respondents are offered three response categories (no problems, some problems, extreme problems), leading to 243 possible health states. These health states are then converted into index based values (utilities) ranging from 0 to 1 by applying a valuation algorithm. The EQ-5D instrument includes a visual analogue scale (VAS), on which the patient is asked to score his/her current health state between 0 (worst imaginable health state) and 100 (best imaginable health state). | Over 15 month follow up | 
| Hospitalization or urgent outpatient visit for atrial fibrillation |  | Within 15 months follow-up post pacemaker | 
| Hospitalization or urgent outpatient visit for heart failure |  | Within 15 months follow-up post pacemaker | 
| Cerebrovascular accident |  | Within 15 months follow-up post pacemaker | 
| Atrial Fibrillation Ablation |  | Within 15 months follow-up post pacemaker | 
| New start or up-titration of medications for the primary diagnosis of atrial fibrillation |  | Within 15 months follow-up post pacemaker |