Left Bundle Branch Area Pacing Versus Right Ventricular Pacing in Atrioventricular Block With Preserved Ejection Fraction (NOVEL II)

Left Bundle Branch Area Pacing With a Stylet-Driven Lead Versus Right Ventricular Pacing in Patients With Atrioventricular Block and Preserved Ejection Fraction: A Multicenter Randomized Trial

Conventional right ventricular pacing (RVP) has been associated with ventricular dyssynchrony and an increased risk of pacing-induced cardiomyopathy, which may lead to worse clinical outcomes. These adverse effects are more pronounced in patients with pre-existing left ventricular dysfunction. To overcome these limitations, left bundle branch area pacing (LBBAP), which directly engages the cardiac conduction system to preserve physiological ventricular activation, has been increasingly adopted in clinical practice.

However, in patients with atrioventricular block and preserved left ventricular ejection fraction (LVEF ≥50%), evidence demonstrating the long-term clinical superiority of LBBAP over conventional RVP remains limited. As a result, both pacing strategies continue to be used in current practice. This multicenter randomized trial aims to compare the efficacy, safety, and lead stability of LBBAP using a stylet-driven extendable screw-in lead versus conventional RVP in patients with atrioventricular block and preserved ejection fraction.

Study Overview

• Status: Recruiting
• Conditions: Atrioventricular Block; Conduction System Pacing; Left Bunde Branch Area Pacing
• Intervention / Treatment: Device: Left Bundle Branch Area Pacing; Device: Right venticular pacing

Detailed Description

Right ventricular pacing (RVP) has been the conventional pacing strategy for patients requiring permanent pacemaker implantation due to bradyarrhythmias. However, chronic RVP has been shown to induce non-physiological ventricular activation, resulting in ventricular dyssynchrony, an increased incidence of pacing-induced cardiomyopathy, and higher long-term morbidity and mortality. These detrimental effects are particularly evident in patients with impaired baseline cardiac function.

Left bundle branch area pacing (LBBAP) has emerged as an alternative physiological pacing strategy that directly captures the cardiac conduction system, thereby preserving synchronized ventricular contraction. Owing to its favorable electrical and hemodynamic characteristics, LBBAP has been increasingly adopted in contemporary clinical practice. Nevertheless, in patients with atrioventricular block and preserved left ventricular ejection fraction (LVEF >50%), robust evidence demonstrating the long-term clinical benefits of LBBAP compared with conventional RVP is lacking. Consequently, both pacing strategies are currently used interchangeably in real-world practice.

Two main types of pacing leads are currently used for LBBAP: lumen-less fixed screw leads (LLFS leads) and stylet-driven extendable screw-in leads (SDES leads). Although several studies have compared short-term clinical outcomes between LBBAP and RVP, the majority of these investigations have utilized LLFS leads. Data evaluating LBBAP performed with SDES leads, particularly in comparison with conventional RVP, remain extremely limited.

Therefore, the present multicenter randomized controlled trial is designed to compare the efficacy, safety, and lead stability of LBBAP using a stylet-driven extendable screw-in lead versus conventional right ventricular pacing in patients with atrioventricular block and preserved left ventricular ejection fraction. The findings of this study are expected to provide clinically relevant evidence to guide optimal pacing strategy selection in this patient population.

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Seung-Jung Park, MD, PhD; Phone Number: 82-2-3410-3419; Email: orthovics@gmail.com

Study Locations

• South Korea
  • Changwon, South Korea
    • Recruiting
    • Samsung Changwon Hospital
    • Contact: Hye Bin Gwag, MD; Phone Number: 82-10-4761-9395; Email: tgfbk@naver.com
  • Seoul, South Korea
    • Recruiting
    • Veterans Health Service Medical Center
    • Contact: Jin Kyung Hwang, MD; Phone Number: 82-10-8870-0768; Email: dangtong@naver.com
  • Gangwon-do
    • Wŏnju, Gangwon-do, South Korea
      • Recruiting
      • Wonju Severance Christian Hospital
      • Contact: Young Jun Park, MD; Phone Number: 82-10-9842-0369; Email: pyj@yonsei.ac.kr
  • Seoul
    • Seoul, Seoul, South Korea, 06351
      • Recruiting
      • Samsung Medical Center
      • Contact: Seung-Jung Park, MD, PhD; Phone Number: 82-2-3410-3419; Email: orthovics@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Patients requiring permanent pacemaker implantation for the following indications:

• Third-degree AV block
• First- or second-degree AV block with an expected ventricular pacing burden ≥40%
• Atrial fibrillation with slow ventricular response with an expected ventricular pacing burden ≥40%

Exclusion Criteria:

• Prior implantation of a cardiac pacemaker or implantable cardioverter-defibrillator
• Left ventricular ejection fraction ≤50%
• Indication for cardiac resynchronization therapy
• Life expectancy ≤1 year (e.g., patients not eligible for heart transplantation due to end-stage heart failure, patients with DNR orders, those receiving hospice care after refusal of life-sustaining treatment, or patients with terminal cancer not eligible for chemotherapy or radiotherapy)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Left bundle branch area pacing; Left bundle branch area pacing performed using a stylet-driven extendable screw-in lead for treatment of atrioventricular block.	Device: Left Bundle Branch Area Pacing; Left bundle branch area pacing performed using a stylet-driven extendable screw-in pacing lead to achieve physiological ventricular activation in patients with atrioventricular block.
Active Comparator: Right ventricular pacing; Conventional right ventricular pacing using a transvenous pacing lead for treatment of atrioventricular block.	Device: Right venticular pacing; Conventional right ventricular pacing performed with a standard transvenous pacing lead for treatment of atrioventricular block.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
LV ejection fraction	% at echocardiography	at 1 years after PPM implantation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
all cause death	incidence (%)	at 1 years after PPM implantation
Cardiac death	incidence (%)	at 1 years after PPM implantation
HF admission	incidence (%)	at 1 years after PPM implantation
Lead dislodgement	incidence (%)	at 1 years after PPM implantation
T wave alternans	during 24 holter monitoring	at 1 years after PPM implantation
NTproBNP	pg/mL	at 1 years after PPM implantation

Collaborators and Investigators

• Sponsor: Samsung Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): April 29, 2024
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: March 6, 2026
• First Submitted That Met QC Criteria: March 6, 2026
• First Posted (Actual): March 11, 2026

Study Record Updates

• Last Update Posted (Actual): March 11, 2026
• Last Update Submitted That Met QC Criteria: March 6, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Heart Block; Pathological Conditions, Signs and Symptoms; Atrioventricular Block
• Other Study ID Numbers: SMC-2023-07-102; FF091 (Other Grant/Funding Number: Biotronik SE & Co. KG)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No