Left Bundle Branch Pacing on Outcomes and Ventricular Remodeling in Biventricular CRT Nonresponders

Summary

Heart failure (HF) is the most common nosology encountered in clinical practice. Its incidence and prevalence increase exponentially with increasing age and it is associated with the increased mortality, more frequent hospitalization and decreased quality of life. An initial approach to the treatment of HF patients with reduced left ventricular (LV) systolic function and left bundle branch block (LBBB) was implantation of device for cardiac resynchronization therapy using biventricular pacing. This has resulted in long-term clinical benefits such as improved quality of life, increased functional capacity, reduced HF hospitalizations and overall mortality. However, conventional cardiac resynchronization therapy (CRT) is effective in only 70% of patients. And the remaining 30% of patients are non-responders to conventional CRT. Cardiac conduction system pacing is currently a promising technique for these patients. Particularly, His bundle pacing (HBP) has been developed to achieve the same results. According to other studies HBP has shown greater improvement in hemodynamic parameters comparing with conventional biventricular CRT. But, nevertheless, there are significant clinical troubles with HBP, especially high pacing threshold. In this regard, in 2017, the left bundle branch pacing (LBBP) was developed, which demonstrated clinical advantages compared to conventional biventricular CRT. Also, since 2019, left bundle branch pacing-optimized CRT (LBBPO CRT) has been used in clinical practice. These methods have become an alternative to HBP due to the stimulation of LBB outside the blocking site, a stable pacing threshold and a narrow QRS complex duration on electrocardiogram. A series of case reports and observational studies have demonstrated the efficacy and safety of LBBP and LBBPO CRT in patients with CRT indications. However, it is not enough data about impact of CRT with LBBP and combined CRT with LBBP and LV pacing on myocardial remodeling, reducing mortality and complications. According to our hypothesis, CRT with LBBP and combined CRT with LBBP and LV pacing compared with conventional biventricular pacing will significantly improve the clinical outcomes and reverse myocardial remodeling in patients who are non-responders to biventricular CRT with HF, reduced LV ejection fraction and with indications to CRT devices with defibrillator function (CRT-D) or one of the CRT-D leads replacement.

Conditions

• Heart Failure
• Left Bundle-Branch Block
• Ischemic Cardiomyopathy
• Non-ischemic Dilated Cardiomyopathy
• Left Ventricular Dysfunction
• Left Ventricle Remodeling

Interventions

DEVICE

Cardiac Resynchronization Therapy Devices with Defibrillator Function (CRT-D) or CRT-D Leads Replacement

The local anesthesia will be performed on the left/right subclavian area after prepping the skin. The device pocket will be opened, the old CRT-D will be removed and disconnected from the leads. The pacing threshold, intracardiac signal amplitude and impedance (pacing and shock) on the atrial, defibrillation and left ventricular leads will be performed. If there is a lead dysfunction, the new lead will be implanted. The new CRT-D will be connected with leads and placed back into the pocket. The pocket will be closed by separate stitches (2-4 suffice) using the resorbable braided suture.

DEVICE

CRT-D or CRT-D Leads Replacement with New Lead Implantation to Left Bundle Branch and Inactivation of Conventional Right and Left Ventricular Pacing

The local anesthesia will be performed on the left/right subclavian area after prepping the skin. The device pocket will be opened, the old CRT-D will be removed and disconnected from the leads. The pacing threshold, intracardiac signal amplitude and impedance (pacing and shock) on the atrial, defibrillation and left ventricular leads will be performed. If there is a lead dysfunction, the new lead will be implanted. The lead implantation to the left bundle branch (LBB) will be performed by transvenous approach and special delivery system. The new CRT-D will be connected with the leads (LBB pacing lead will be connected to defibrillation lead (DL) IS-1 connector of CRT-D and IS-1 tip of DL will be capped) and placed back into pocket. The pocket will be closed by separate stitches (2-4 suffice) using the resorbable braided suture. RV and LV pacing will be inactivated and only LBB pacing will be switched on.

DEVICE

CRT-D or CRT-D Leads Replacement with New Lead Implantation to Left Bundle Branch and Inactivation of Conventional Right Ventricular Pacing

The local anesthesia will be performed on the left/right subclavian area after prepping the skin. The device pocket will be opened, the old CRT-D will be removed and disconnected from the leads. The pacing threshold, intracardiac signal amplitude and impedance (pacing and shock) on the atrial, defibrillation and left ventricular leads will be performed. If there is a lead dysfunction, the new lead will be implanted. The lead implantation to the left bundle branch (LBB) will be performed by transvenous approach and special delivery system. The new CRT-D will be connected with the leads (LBB pacing lead will be connected to defibrillation lead (DL) IS-1 connector of CRT-D and IS-1 tip of DL will be capped) and placed back into pocket. The pocket will be closed by separate stitches (2-4 suffice) using the resorbable braided suture. LBB and LV pacing will be switched on.

Sponsors & Collaborators

• Tomsk National Research Medical Center of the Russian Academy of Sciences

  lead OTHER

Principal Investigators

• Tariel A Atabekov, Ph.D. · Cardiology Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences

• Roman E Batalov, M.D. · Cardiology Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-11-01

Primary Completion

2028-06-01

Completion

2028-09-01

Countries

• Russia

Study Locations