Left Bundle Branch Pacing Versus Conventional Pacing in Atrioventricular Block

Study Overview
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Brief Summary
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Recently, the concept of physiological pacing has emerged in the clinical practice, in an attempt to prevent the deteriorating effects of right ventricular pacing in the long-term. Left bundle branch pacing seems to be a safe procedure with promising results that may prevent intraventricular dyssynchony compared with the conventional right ventricular pacing.

Detailed Description
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In this prospective, randomized study the outcomes regarding echocardiographic indices of dyssynchrony in left bundle branch versus conventional right ventricular pacing in patients with atrioventricular node disease will be compared In recent years, His pacing has demonstrated better results regarding resynchronization compared to conventional biventricular pacing in trials of 3D mapping. However, technical difficulties that relate to unstable lead positioning or inability in succeeding low pacing threshold have led to low success rates. An alternative site of physiological pacing that could possibly overcome these issues, while maintaining ventricular synchrony is left bundle branch pacing. The lead implantation of LBB pacing is performed using the Select Secure (3830) pacing lead. The lead is screwed into the interventricular septum, until left bundle branch pacing is achieved. The randomized patients 24 hours after the procedure are echocardiographically evaluated and indices of mechanical dyssynchrony are recorded. Follow-up is conducted at 3 months, 6 months and one year post-procedure.

Official Title
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Left Bundle Branch Pacing Versus Conventional Pacing in Patients With Atrioventricular Node Disorders: a Randomized, Control Study

Conditions
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Atrioventricular Nodal Disease

Intervention / Treatment
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* Device: Left bundle branch pacing lead (Select Secure 3830 lead)
* Device: Right ventricular active fixation lead


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age>18 years old Patients with atrioventricular block and EF>50% with a predicted ventricular pacing rate>20% Patients with intraventricular septal diameter>8mm Written informed consent Exclusion Criteria: Indication for CRT or ICD device Patients with no subclavian approach, who are candidates for leadless devices Presence of severe tricuspid regurgitation Patients who are candidates for implantation from the right side, as currently the provided tools for left bundle branch pacing fascilitate only left sided pacemaker implantations

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Left Bundle Branch Pacing<br>Implantation of a left bundle branch lead via sheath, to perform left bundle branch pacing | Device: Left bundle branch pacing lead (Select Secure 3830 lead)<br>* Implantation of a left bundle branch pacing lead via sheath<br>|
| Active Comparator: Conventional Right Venticular Pacing<br>The ventricular lead will be implanted in the right ventricle in the conventional way | Device: Right ventricular active fixation lead<br>* Active fixation lead (standard)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Echocardiographic dyssynchrony index, as expressed with Global Left Ventricular Myocardial Work Efficiency (GWE) (%) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and the global left ventricular work efficiency- as a measure of dyssynchrony- will be recorded. | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Procedure Time (min) | The total time required for the completion of the procedure | 1 Day of procedure | 
| Fluoroscopy Time (min) | The total time of fluoroscopy | 1 Day of procedure | 
| Dose Area Product (DAP) (cGy/cm2) | Total Radiation Dose as expressed with DAP | 1 Day of procedure | 
| Implant success | Successful implantation with pacing threshold<2 V | 1 Day of procedure | 
| Complications associated with pacemaker implantation | General device related complications: pneumothorax, hemothorax, infection, tamponade, hematoma, lead reoperation Specific complications associated with the left bundle branch pacing procedure: intraventricular septum rupture, septal perforator branch injury with subsequent myocardial infarction or lead displacement | through study completion at 1 year post randomisation | 
| B natriuretic peptide measurement (pg/ml) | Blood samples are extracted in all patients at baseline, 3 months, 6 months and one year after the procedure | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Stroke volume index (SVi) (ml/m2) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and the SVi will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Ejection Fraction (EF) (%) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and the EF will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Global Longitudinal Strain (GLS) (%) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and the GLS will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Left Atrium Strain (%) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and the Left Atrium Strain will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Left Atrium Strain Rate (1/s) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and the Left Atrium Strain Rate will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Aortic Time- Velocity Integral (TVI) (cm) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and the aortic TVI will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Global Work Index (GWI) (mmHg%) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and GWI will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Global Constructive Work (GCW) (mmHg%) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and GCW will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Global Wasted Work (GWW) (mmHg%) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and GWW will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Segmental CW, WW at the mid septal wall | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and segmental WI, CW, WW at the mid septal wall will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Segmental CW, WW at the basal lateral wall | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and segmental WI, CW, WW at the basal lateral wall will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Peak Strain Dispersion (PSD) (msec) | Follow-up transthoracic echocardiography will be held 24 hours, 3 months, 6 months and one year after the procedure and PSD will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Changes in capture threshold (V) in the ventricular lead | The device will be interrogated at baseline, 3 months, 6 months and one year after the procedure and the potential changes in capture threshold in the ventricular lead will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure | 
| Changes in sense (mV) in the ventricular lead | The device will be interrogated at baseline, 3 months, 6 months and one year after the procedure and potential changes in sense in the ventricular lead will be recorded | 24 hours after the procedure as baseline and change at 3 months, 6 months and one year post-procedure |