Sick Sinus SyndromeCLOSE-AVNCT07314008
Left Bundle Branch Versus Minimized Ventricular Pacing in Patients With Sick Sinus Syndrome and Prolonged AV Interval
A study testing LBBAP and MVP in people with Sick Sinus Syndrome and Atrioventricular Nodal Dysfunction, run by Asan Medical Center at 1 site in South Korea.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Sick Sinus Syndrome, Atrioventricular Nodal Dysfunction
- What is being tested?
- LBBAP and MVP
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 440 participants
- Where
- 1 siteSouth Korea
- Study dates
- 2 May 2025to 31 Jan 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- >18 years old
- Sinus node dysfunction with symptoms
- Atrioventricular conduction delay (PR interval > 200ms)
Who cannot join
- 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
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- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
South Korea1 site, 1 recruiting
- Recruiting
Asan Medical Center
Seoul, Songpa-gu, 05505
Gi-byoung Nam, +82 2-3010-3167, gbnam1@gmail.com
About this study
Official title: 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
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:
Read more
*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.
Read the 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.
- Being tested
- LBBAP, MVP
- Medical subject headings
- Sick Sinus Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LBBAPDevice
- 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.
MVPDevice
- 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.
| Study group | Role | What they receive |
|---|---|---|
| LBBAP | Experimental | Not described Receives: Device: LBBAP |
| MVP | Active comparator | Not described Receives: Device: MVP |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of composite of all-cause mortality, heart failure hospitalization and persistent atrial fibrillation
- 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.
Measured: 2 years
Secondary outcomes (8)
- All cause mortality
All cases of mortality after randomization will be counted.
Measured: 2 years
- Ischemic stroke or systemic embolism
Composite of ischemic stroke or systemic embolism during follow-up
Measured: 2 years
Heart failure rehospitalization
- 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
Measured: 2 years
Any rehospitalization
Any rehospitalization after randomization
Measured: 2 years
Rehospitalization from cardiac cause
Rehospitalization for the deterioration of cardiovascular conditions
Measured: 2 years
Quality of life measurement
Quality 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.
Measured: 2 years
Incidence of Clinical AF
AF detected on 12-lead or other forms of ECG
Measured: 2 years
Quality of life measurement
Quality of life questionnaire and baseline and 24 months. Quality of life will be assessed using the 36-Item Short Form Health Survey (SF-36). This instrument comprises 36 questions covering 8 health domains. Each domain is scored on a scale from 0 to 100, with higher scores indicating a better quality of life/health status
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jan 2026
- Study start2 May 2025
- Primary completion31 Jan 2029 (estimated)
- Study completion31 Jan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sick Sinus SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 440 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Asan Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- Severance Hospital, Samsung Medical Center, Seoul National University Hospital
- Responsible party
- Principal investigator, Gi-Byoung Nam, Asan Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07314008
- Sponsor's protocol ID
- AMC2024-0579
- Acronym
- CLOSE-AV
- Status last verified
- May 2025
- First submitted
- 24 Nov 2025
- Last updated
- 2 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT07314008
- Acronym / sponsor ID
- CLOSE-AV / AMC2024-0579
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 440 participants (estimated)
- Lead sponsor
- Asan Medical CenterUniversity, hospital or other
- Collaborators
- Severance Hospital, Samsung Medical Center, Seoul National University Hospital
- Study start
- 2 May 2025 (actual)
- Primary completion
- 31 Jan 2029 (estimated)
- Study completion
- 31 Jan 2029 (estimated)
- First posted
- 2 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| LBBAP | Experimental | Device: LBBAP |
| MVP | Active comparator | Device: MVP |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- >18 years old
- Sinus node dysfunction with symptoms
- Atrioventricular conduction delay (PR interval > 200ms)
Key exclusion criteria (11 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| LBBAP* 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. | Device | LBBAP |
| MVP* 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. | Device | MVP |
Primary outcome
Rate of composite of all-cause mortality, heart failure hospitalization and persistent atrial fibrillation
Time frame: 2 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.
8 secondary outcomes
- All cause mortality
Time frame: 2 years
- Ischemic stroke or systemic embolism
Time frame: 2 years
Heart failure rehospitalization
Time frame: 2 years
Any rehospitalization
Time frame: 2 years
Rehospitalization from cardiac cause
Time frame: 2 years
Quality of life measurement
Time frame: 2 years
Incidence of Clinical AF
Time frame: 2 years
Quality of life measurement
Time frame: 2 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Jan 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing LBBAP and MVP in people with Sick Sinus Syndrome and Atrioventricular Nodal Dysfunction, run by Asan Medical Center at 1 site in South Korea.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rate of composite of all-cause mortality, heart failure hospitalization and persistent atrial fibrillation (time frame: 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jan 2026.