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Left Bundle Branch Versus Minimized Ventricular Pacing in Patients With Sick Sinus Syndrome and Prolonged AV Interval

Comparison of Left Bundle Branch Area Pacing and Minimized Ventricular Pacing in Patients With Sinus Node Dysfunction and Atrioventricular Conduction Delay: A Multicenter, Randomized Controlled Clinical Trial

Status
Recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07314008
Acronym
CLOSE-AV
Enrollment
440
Registered
2026-01-02
Start date
2025-05-02
Completion date
2029-01-31
Last updated
2026-01-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Atrioventricular Nodal Dysfunction, Sick Sinus Syndrome

Brief summary

The goal of this clinical trial is to compare two pacemaker strategies: Left Bundle Branch Area Pacing (LBBAP) and Minimized Ventricular Pacing (MVP) in patients requiring a permanent pacemaker for sick sinus syndrome and prolonged AV interval. It will also evaluate the safety and feasibility of the LBBAP method in these patients. The main questions it aims to answer is: \*Is LBBAP with physiological AV interval better than Minimized Ventricular Pacing? Researchers will compare the LBBAP group (aiming for conduction system capture with physiological AV intervals) to the MVP group (aiming to minimize ventricular pacing with prolonged AV intervals) to evaluate the optimal pacing strategy. Participants will: * Be randomly assigned to either the LBBAP group or the MVP group. * Undergo a pacemaker implantation procedure according to the specific criteria for their assigned group. * Visit the clinic for regular checkups to measure pacing function and ensure the device settings remain compliant with the study protocol.

Detailed description

Eligible subjects who provide written informed consent will be randomly assigned in a 1:1 ratio to either the LBBAP group or the MVP group. Randomization will be available 24 hours a day using an Interactive Web Response System (IWRS). Randomization will be stratified by the presence of a history of AF. For patients who meet the inclusion and exclusion criteria before the procedure, randomization will be performed beforehand. For patients with SSS requiring PPM implantation, whose AV conduction status cannot be evaluated before the procedure due to conditions such as junctional rhythm, marked bradycardia (\<50 bpm), or isorhythmic dissociation, randomization can be performed after the demonstration of PR with atrial pacing at a targeted atrial rate of 60 bpm during the procedure. LBBAP group * All pacemaker implantation should be performed in a standard manner. * A lead should be placed in the right atrial appendage or septum where acceptable sensing (P wave \>1mV) and pacing threshold (\<1V at 0.4ms width) are achieved. * V lead should be placed in the right ventricular septum where conduction system pacing can be achieved with acceptable sensing and pacing threshold. The pacing morphology should be compatible with His bundle pacing, right ventricular pacing, selective and non-selective left bundle branch pacing, or left fascicular pacing. LBB pacing -Lead position deep in the interventricular septum, \ 1-2cm from the distal His bundle potential, LBB potential to QRS interval in the range of 15-34 ms, normal QRS axis, fulfilled criteria for conduction system capture. Left fascicular pacing -Capture of the LBB fascicles or its distal arborization, short potential to QRS interval (\<25ms), abnormal paced QRS axis with presence of criteria for conduction system capture. Pacing is more distant from the His bundle (2-4cm), defined as left anterior, mid-septal, and posterior fascicle. Left ventricular septal pacing) * Capture of the left side of the interventricular septum without direct activation of the left conduction system. * Terminal R-wave in V1, deep septal position of the pacing lead in the basal to mid-septal area, absence of criteria for conduction system capture. The primary objective for the LBBAP group is the achievement of conduction system capture with LBBAP. However, based on the physician's discretion or the situations in the operating room, His bundle pacing can be accepted as alternatives to LBBAP. MVP group * All pacemaker implantation should be performed in a standard manner. * A lead should be placed in the right atrial appendage or septum where acceptable sensing (P wave \>1mV) and pacing threshold (\<1V at 0.4ms width). * V lead should be placed in the right ventricular apex or septum where acceptable sensing (R wave \>5mV) and pacing threshold (\<1V at 0.4ms width). * The RythmiQ™ mode should be turned on. * Sensing and pacing AV intervals recommended to be \>300ms (default value or more), and should not be \<200ms to minimize the ventricular pacing.

Interventions

DEVICELBBAP

* All pacemaker implantation should be performed in standard manner. * A lead should be placed in the right atrial appendage or septum where acceptable sensing (P wave \>1mV) and pacing threshold (\<1V at 0.4ms width). * V lead should be placed in the right ventricular septum where conduction system pacing can be achieved with acceptable sensing and pacing threshold. The pacing morphology should be compatible with His bundle pacing, right ventricular pacing, selective and non-selective left bundle branch pacing, or left fascicular pacing. * The primary objective for the LBBAP group is the achievement of conduction system capture with LBBAP. However, based on the physician's discretion or the situations in the operating room, His bundle pacing can be accepted as alternatives to LBBAP.

DEVICEMVP

* All pacemaker implantation should be performed in standard manner. * A lead should be placed in the right atrial appendage or septum where acceptable sensing (P wave \>1mV) and pacing threshold (\<1V at 0.4ms width). * V lead should be placed in the right ventricular apex or septum where acceptable sensing (R wave \>5mV) and pacing threshold (\<1V at 0.4ms width) * The rhythmiQTM mode should be turned on * Sensing and pacing AV intervals recommended to be \>300ms (default value or more), and should not be \<200ms to minimize the ventricular pacing.

Sponsors

Severance Hospital
CollaboratorOTHER
Samsung Medical Center
CollaboratorOTHER
Seoul National University Hospital
CollaboratorOTHER
Asan Medical Center
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* \>18 years old * Sinus node dysfunction with symptoms * Atrioventricular conduction delay (PR interval \> 200ms)

Exclusion criteria

* Subject was unable to provide written informed consent or participate in long-term follow-up. * Permanent atrial fibrillation * Pre-existing cardiac implantable electronic device * Persistent advanced atrioventricular conduction disturbance (2:1 block, Mobitz type II, or 3rd degree) * Mechanical tricuspid valve * Ventricular septal defect or scar * Left ventricular ejection fraction \< 35% who indicated cardiac resynchronization therapy * Previous heart transplantation * Pregnant and/or lactating women * Life expectancy \<2 year * Patients who are actively participating in another drug or device investigational study, which have not completed the primary endpoint follow-up period

Design outcomes

Primary

MeasureTime frameDescription
Rate of composite of all-cause mortality, heart failure hospitalization and persistent atrial fibrillation2 years* All cases of mortality after randomization will be counted. * Worsening heart failure includes heart failure hospitalization or urgent heart failure visit (outpatient or emergency department) * Persistent atrial fibrillation is defined when there are at least seven consecutive days with 22 hours of device-recorded AF per day or at least one day with an episode of AF lasting at least 22 hours, which is interrupted by electrical or chemical cardioversion.

Secondary

MeasureTime frameDescription
- All cause mortality2 yearsAll cases of mortality after randomization will be counted.
Heart failure rehospitalization2 years* The patient is admitted to the hospital with a primary diagnosis of HF * The patient's length-of-stay in hospital extends for at least 24 hours * The patient exhibits documented at least one new or worsening symptoms due to HF on presentation * The patient has objective evidence of new or worsening HF, consisting of at least two physical examination findings or one physical examination and one laboratory criterion. * The patient receives at least one of the following treatments specifically for HF
Quality of life measurement2 yearsQuality of life questionnaire and baseline and 24 months. Quality of life is assessed using: 1) 36-Item Short Form Health Survey (SF-36), and 2) Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12). Both scales range from 0 to 100, with higher scores indicating better health status.
Incidence of Clinical AF2 yearsAF detected on 12-lead or other forms of ECG
Rehospitalization from cardiac cause2 yearsRehospitalization for the deterioration of cardiovascular conditions
Any rehospitalization2 yearsAny rehospitalization after randomization
- Ischemic stroke or systemic embolism2 yearsComposite of ischemic stroke or systemic embolism during follow-up

Other

MeasureTime frameDescription
Procedural successPeriproceduralAchievement of LBB area pacing (%)
Periprocedural complicationsPeriproceduralComplications related to the procedure
Incidence of subclinical AF with pre-specified durations2 yearsAF lasting \>5min, \>1 hour, \>6 hours, \>1 day, and \>7 days

Countries

South Korea

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026