Closed-Loop Stimulation in Left Bundle Branch Area Pacing

NCT07812935 | Completed

• 1 other identifier: 039/05/2025
• Study Type: interventional
• Target: 33
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective, single-center, crossover study evaluated the effects of closed-loop stimulation (CLS) compared with conventional accelerometer-based rate-adaptive pacing (VVIR) in patients with permanent atrial fibrillation undergoing left bundle branch area pacing (LBBAP). Chronotropic responses were evaluated during standardized mental and physical stress testing. Heart rate distribution during daily activity, functional capacity, quality of life, and device-related parameters were also assessed.

Conditions

Block Complete Heart; Atrial Fibrillation (AF); Chronotropic Incompetence

Keywords

left bundle branch area pacing; closed loop stimulation; LBBAP; CLS; Rate adaptive pacing; cardiac pacing

Outcome Measures

Primary Outcomes (3)

• Change in Heart Rate During Mental Stress

  Change in heart rate (ΔHR) during the Paced Auditory Serial Addition Test (PASAT), calculated as the peak heart rate recorded during the test minus the baseline heart rate. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing and expressed in beats per minute (bpm).

  At the end of each 1-month pacing period

• Change in Heart Rate During Isometric Handgrip

  Change in heart rate (ΔHR) during the 5-minute isometric handgrip test performed at 30% of maximal voluntary contraction, calculated as the peak heart rate recorded during the test minus the baseline heart rate. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing and expressed in beats per minute (bpm).

  At the end of each 1-month pacing period

• Change in Heart Rate During Treadmill Exercise

  Change in heart rate (ΔHR) during the symptom-limited treadmill exercise test using the modified Bruce protocol, calculated as the peak heart rate achieved during exercise minus the baseline heart rate. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing and expressed in beats per minute (bpm).

  At the end of each 1-month pacing period

Secondary Outcomes (7)

• Exercise Duration During Treadmill Testing

  At the end of each 1-month pacing period

• Metabolic Equivalents Achieved During Treadmill Testing

  At the end of each 1-month pacing period

• Heart Rate Score During Daily Activity

  At the end of each 1-month pacing period

• Health-Related Quality of Life Assessed With the EQ-5D-5L Index

  At the end of each 1-month pacing period

• Self-Rated Health Assessed With the EQ VAS

  At the end of each 1-month pacing period

Study Arms (2)

CLS followed by VVIR

EXPERIMENTAL

Participants received closed-loop stimulation (CLS) during the first study period, followed by accelerometer-based VVIR pacing during the second study period.

Device: Closed-Loop Stimulation; Device: Accelerometer-Based VVIR Pacing

VVIR followed by CLS

EXPERIMENTAL

Participants received accelerometer-based VVIR pacing during the first study period, followed by closed-loop stimulation (CLS) during the second study period.

Device: Closed-Loop Stimulation; Device: Accelerometer-Based VVIR Pacing

Interventions

Accelerometer-Based VVIR Pacing DEVICE

The pacemaker was programmed to VVIR mode with accelerometer-based rate-adaptive pacing. The pacing rate was adjusted according to physical activity detected by the device's accelerometer.

CLS followed by VVIR; VVIR followed by CLS

Closed-Loop Stimulation DEVICE

The pacemaker was programmed to closed-loop stimulation (CLS), an impedance-based rate-adaptive pacing algorithm that adjusts the pacing rate in response to changes in intracardiac impedance associated with cardiac contractile dynamics.

CLS followed by VVIR; VVIR followed by CLS

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥18 years
• Permanent atrial fibrillation
• Chronotropic incompetence
• Permanent pacemaker with left bundle branch area pacing (LBBAP)
• Ventricular pacing burden \>50%
• Ability to provide written informed consent

You may not qualify if:

• Age \<18 years
• Inability or unwillingness to provide informed consent

Sponsors & Collaborators

• Bartlomiej Wrobel: lead

Study Sites (1)

Clinical Provincial Hospital No. 2 in Rzeszow

Rzeszów, Podkarpackie Voivodeship, 35-302, Poland

Location

MeSH Terms

Conditions

Atrial Fibrillation

Condition Hierarchy (Ancestors)

Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants were blinded to the programmed pacing mode. Investigators and outcome assessors were not blinded.
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Assistant

Model Details: Participants underwent two consecutive pacing periods, one with closed-loop stimulation (CLS) and one with accelerometer-based VVIR pacing. Seventeen participants started with CLS followed by VVIR, whereas 16 participants started with VVIR followed by CLS. The order of pacing modes was not randomized.

Study Record Dates

• First Submitted: August 29, 2026
• First Posted: September 10, 2026
• Study Start: June 23, 2025
• Primary Completion: July 27, 2026
• Study Completion: July 27, 2026
• Last Updated: September 10, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

PL (1)