An interventional study of Left bundle branch pacing and Right ventricular pacing in Atrioventricular Block, sponsored by The First Affiliated Hospital with Nanjing Medical University. Active, not recruiting at 1 site in China. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-14.
Sponsored by The First Affiliated Hospital with Nanjing Medical University · Not applicable, Interventional, and Treatment
Among 15 studies in Atrioventricular Block with a site in China — 5 open to participants now, 6 under way, none of them phase 3. Atrioventricular Block · China.
Among the 15 studies in Atrioventricular Block with a site in China, this one is one of 2 that started in 2021, is one of 8 with no phase, and was the 3rd registered.
117 studies on the registry are indexed under Atrioventricular Block; 43 are open to participants now.
This study's planned enrollment of 683 is above the median of 127 across 78 interventional studies indexed under Atrioventricular Block.
Browse Atrioventricular Block studies →5 of the 15 studies in Atrioventricular Block with a site in China are open now.
A study can be open while its sites in China have not opened yet or have stopped. Only those recruiting at a site in China →
Of the 29 Atrioventricular Block studies recruiting now, 21 (72%) set no upper age limit and 4 (14%) stop at 75 or younger; 1 take children under 18; 1 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →15 studies; the count open now beside each. This study's row is marked.
First in 2015; this study’s year is marked. 2 started in 2021.
Median enrollment 387 across the 8 interventional studies, 60 across the 7 observational. Of the 4 that completed or were terminated, 1 (25%) have results posted.
2 of 15 have an industry lead sponsor. The 10 most frequent:
The First Affiliated Hospital with Nanjing Medical University is the lead sponsor of 568 studies on the registry; 317 are open to participants now.
The First Affiliated Hospital with Nanjing Medical University has 1 study filed under Atrioventricular Block — fewer than ten, so there is no comparison to draw.
2 of the studies in Atrioventricular Block with a site in China that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07378124Ningbo No.2 HospitalLLL vs. SDL for LBBP: A Non-inferiority RCT | 2027-06-30 |
| NCT07802119Min ShenTransjugular Approach for Implantation of Active Fixation Leadless Pacemakers | 2027-09-30 |
Among the 15 studies in Atrioventricular Block with a site in China, from their registry updates:
OptimPacing study has been designed as a prospective, multi-center, randomized, controlled trial. A total of 11 medical centers across China will enroll 683 patients over an estimated recruitment period of 2 years. An LBBP group will be compared with a group of conventional RVP in the follow-up of at least 3 years. The study aimed to demonstrate (1) the superiority of LBBP in preserving LV systolic function over RVP and (2) the feasibility and long-term safety of LBBP in patients with AV block.
Introduction
Right ventricular pacing (RVP) has been the standard-of-care therapy for patients with bradycardia for sixty years. However, the selection of optimal pacing site is still controversial. Right ventricular septal or outflow tract pacing has not resulted in improved outcomes. RVP is considered to result in electrical and mechanical dyssynchrony and an increased risk of pacing-induced cardiomyopathy (PICM), heart failure and mortality. Biopace (Biventricular Pacing for Atrioventricular Block to Prevent Cardiac Desynchronization) study is a randomized controlled trial with a large population evaluating biventricular pacing versus RVP in patients with atrioventricular (AV) block. But biventricular pacing was not shown superiority in clinical outcomes compared with RVP. As biventricular pacing is delivered at two non-physiological sites, it actually creates ventricular dyssynchrony in patients with narrow QRS durations. Thus, seeking for the optimal pacing site has been the ultimate goal of doctors who specialize in cardiac pacing.
His-bundle pacing (HBP) is thought to be the most physiological pacing modality, which was initial applied by Deshmukh et al in 2000. HBP activates native His-Purkinje system and produces favorable electrical and mechanical synchrony. Clinical observations have shown HBP could reduce the incidence of PICM and improve combined clinical outcomes. However, HBP is not widely applied because of challenging operating techniques, unstable long-term pacing parameters and risk of loss of ventricular capture in a significant number of patients.
Left bundle branch pacing (LBBP) was first introduced by Huang et al in 2017. Since then, LBBP has been carried out boomingly in China. Similar with HBP, LBBP could activate left bundle branch (LBB) fibers and provide narrower paced QRS duration and better left ventricular (LV) mechanical synchrony than RVP. Animal studies also confirmed the physiological characteristics and anatomical lead locations of LBBP. Several clinical studies showed that LBBP could produce significantly narrower paced QRS duration and better echocardiographic response than biventricular pacing in patients with heart failure and LBB block. Furthermore, the implantation procedure appears easier and capture threshold is lower when compared with HBP. LBBP has appeared to be a promising approach in the clinical practice. However, no randomized controlled studies have been reported to compare the efficacy of LBBP and other pacing modalities.
Objectives
The study aimed to demonstrate (1) the superiority of LBBP in preserving LV systolic function over RVP and (2) the feasibility and long-term safety of LBBP in patients with AV block.
Methods
Stratified randomization
A balanced randomization is applied according to the following stratifying criteria:
Lead implantation of LBBP
The lead implantation of LBBP has been well described previously. The implantation was performed using the Select Secure (3830) pacing lead delivered through a fixed-curve sheath. The 3830 lead was introduced transvenously into the right ventricle and screwed into the interventricular septum (IVS) until LV septum was reached, without protruding into the LV cavity.
Venous access was obtained via the left axillary vein or subclavian vein. The 3830 lead was inserted through the C315 HIS sheath. An intracardiac electrogram was recorded from the lead tip using the electrophysiological recording system. His-bundle electrogram was identified at the right anterior oblique 25° position and fluoroscopic image of the lead position was recorded as a reference. The sheath and lead tip were first advanced to the anterior lower site of the His-bundle position, and subsequently rotated in a counterclockwise fashion to place the lead tip in a perpendicular orientation to the IVS. A paced morphology of QS complex with a north in the nadir ("W"-shaped morphology) in surface lead V1 was usually observed at this location. As the lead tip was gradually screwed into the IVS, a rightward shift of the second notch in the "W"-shaped pacing morphology can be observed. The lead tip was considered to be in the final position once a paced morphology of right bundle branch delay (RBBD) in surface lead V1 was achieved. Moreover, a discrete potential before the QRS complex could be often recorded from the lead tip, and we defined this potential as the LBB potential. Left ventricular activation time (LVAT) was measured from the intracardiac pacing spike to the R-wave peak of QRS complex in lead V5 or V6. The penetration depth in the IVS was finally assessed by injecting a small amount of contrast medium through the sheath in left anterior oblique 45°. Echocardiography was routinely performed to evaluate the lead depth in the IVS before discharge.
Device programming
The devices are routinely programmed with a lower rate limit of 60 ppm. For DDD devices, the paced and sensed AV intervals are set as 150 and 120 ms, respectively.
Study organization
Echocardiographic core lab Echocardiographic examinations are performed at each study center before pacemaker implantation and at follow-up. All images are stored on DVD disks and sent to the core lab (Zhongshan Hospital, Fudan University) for central analysis.
Study Steering Committee
The study steering committee is composed of three experts who are not the investigators of this study. The committee is responsible for the academic issues including the judgment of LBBP or LVSP.
Independent Data Monitoring Committee (iDMC)
The iDMC is composed of three experts including at least one statistical expert. The committee is responsible for the data examination including mid-term evaluation during the study and also the patient privacy protection.
Safety Review Committee
The safety review committee is composed of three experts who are not the investigators of this study. In case of severe adverse events, including all-cause death, acute cardiovascular or cerebrovascular events and other lethal or disabling diseases, the committee will be responsible for the investigation of the events. The physicians should report the events to the principal investigator of each center and the committee within 2 hours. The committee should report the events to the hospital ethics committee in 24 hours. The committee may recommend the early termination of the study if an excessive rate of adverse events is suspected.
Statistical analysis
Intention-to-treat principle
Data analyses are performed according to the intention-to-treat principle. If LBBP or LVSP fails, RVP will be performed and the patient will not be crossed over to the other group. If LBBP fails but LVSP succeeds, the sub-group analysis for these patients with LVSP will be done.
Sample size
According to previous publications of HBP and RVP, we supposed that the rate of 5-year composite endpoints in RVP group was 25% and the rate in LBBP group was 15%. With a recruitment period of 2 years and follow-up time of at least 3 years, at least 100 events are required to achieve a power of 80%. With alpha as 0.05, rate of lost-of-follow-up rate as 10%, the final sample size was estimated as 683 by using PASS Version 15.
Endpoint analysis
Kaplan-Meier analysis was used to compare the rate of endpoints between the two groups over time. Cox proportional risk model will be applied to calculate the hazard ratio. A p-value less than 0.05 was considered statistically significant.
Mid-term analysis
Mid-term analysis is performed by iDMC when the rate of events reaches 50% (at least 50 events of primary endpoint). If LBBP group exhibits statistically significant superiority over RVP group with the significant level of 0.003, the study could be effectively early terminated. Otherwise, the sample size will be re-evaluated. The iDMC may determine if the study will continue according to the re-evaluation of the sample size. Eventually, the data prior to and after the mid-term analysis are put together for final analysis with the significant level of 0.047.
Statistical software
All statistical analyses were performed using SAS Version 9.4 or R Software Version 3.6.
Study timeframe
The study will start in October 2020 and the complete enrollment will be expected by the end of 2022. At least 11 medical centers across China will participate in the study. With a period of at least 3-year follow-up, the study is expected to finish at the end of 2025. The recruitment might be slower if the mid-term analysis does not reach the statistical significance and a larger population is required.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
In this arm, a left bundle branch pacing(LBBP) lead is attempted to be placed.
Procedure: Left bundle branch pacing
In this arm, a right ventricular pacing(RVP) lead are placed.
Procedure: Right ventricular pacing
LBBP is defined if fulfilling criterion 1 and at least one in criteria 2: 1. Paced morphology of RBBD in surface lead V1 (QR, Qr, rSr', rSR' or Qrs); 2. One of the following should be met: 1. Selective LBBP with an iso-electrical window between the pacing spike and QRS onset; 2. If using dual-lead method with one at His-bundle and the other at LBB region, a retrograde His-bundle potential is recorded from His-bundle lead during LBBP; 3. LVATs at lead tip pacing of 1.5V/0.5ms and 10V/0.5ms are ≤ 80ms and the difference is \< 10ms; 4. A discrete LBB potential is recorded from lead tip and LVAT at tip pacing of 3V/0.5ms is ≤ 80ms19. If criterion 1 is fulfilled but none in criteria 2 is met, the procedure is considered to be left ventricular septal pacing (LVSP).
Implantation of a RV pacing lead is attempted using the standard-of-care technique first.
A combined clinical endpoint of all-cause mortality, hospitalization for heart failure(HF) and/or occurrence of pacing-induced cardiomyopathy(PICM)
Incidence of all-cause death, hospitalization for HF and/or PICM
Time frame: 6-month follow-up
A combined clinical endpoint of all-cause mortality, hospitalization for heart failure(HF) and/or occurrence of pacing-induced cardiomyopathy(PICM)
Incidence of all-cause death, hospitalization for HF and/or PICM
Time frame: 12-month follow-up
A combined clinical endpoint of all-cause mortality, hospitalization for heart failure(HF) and/or occurrence of pacing-induced cardiomyopathy(PICM)
Incidence of all-cause death, hospitalization for HF and/or PICM
Time frame: 24-month follow-up
A combined clinical endpoint of all-cause mortality, hospitalization for heart failure(HF) and/or occurrence of pacing-induced cardiomyopathy(PICM)
Incidence of all-cause death, hospitalization for HF and/or PICM
Time frame: 36-month follow-up
Left ventricular ejection fraction(LVEF)
Changes from baseline LVEF(unit: %) assessed by echocardiography at follow-up
Time frame: Baseline; 6-month, 12-month, 24-month and 36-month follow-up
Left ventricular end systolic volume(LVESV)
Changes from baseline LVESV(unit: mL) assessed by echocardiography at follow-up
Time frame: Baseline; 6-month, 12-month, 24-month and 36-month follow-up
Left ventricular end diastolic volume(LVEDV)
Changes from baseline LVEDV(unit: mL) assessed by echocardiography at follow-up
Time frame: Baseline; 6-month, 12-month, 24-month and 36-month follow-up
Left ventricular end systolic diameter(LVESD)
Changes from baseline LVESD(unit: mm) assessed by echocardiography at follow-up
Time frame: Baseline; 6-month, 12-month, 24-month and 36-month follow-up
Left ventricular end diastolic diameter(LVEDD)
Changes from baseline LVEDD(unit: mm) assessed by echocardiography at follow-up
Time frame: Baseline; 6-month, 12-month, 24-month and 36-month follow-up
Interventricular movement time difference(IVMD)
Changes from baseline IVMD(unit: ms) assessed by echocardiography at follow-up
Time frame: Baseline; 6-month, 12-month, 24-month and 36-month follow-up
Septal-to-posterior wall motion delay(SPWMD)
Changes from baseline SPWMD(unit: ms) assessed by echocardiography at follow-up
Time frame: Baseline; 6-month, 12-month, 24-month and 36-month follow-up
Changes in concentration of NT-proBNP in blood between baseline and follow-up
Blood test is performed at each time frame to determine the concentration of NT-proBNP(unit: pg/mL)
Time frame: Baseline; 6-month,12-month, 24-month and 36-month follow-up
Changes in New York Heart Association Heart Function Classification between baseline and follow-up
The higher the classification, the more severe the heart failure symptoms(four levels: I, II, III and IV)
Time frame: Baseline; 6-month,12-month, 24-month and 36-month follow-up
Changes in 6-minute Walk Distance between baseline and follow-up
Distance that a participant walk within 6 minutes
Time frame: Baseline; 6-month,12-month, 24-month and 36-month follow-up
Change in Quality Of Life Questionnaire score between baseline and follow-up
Reflect the effect of cardiac funtion on quality of life, and higher scores represent a worse outcome
Time frame: Baseline; 6-month,12-month, 24-month and 36-month follow-up
Pacing parameters
Percentage of ventricular pacing, burden of atrial fibrillation, events of NSVT or VT
Time frame: Before discharge; 1-month, 3-month, 6-month, 12-month, 24-month and 36-month follow-up
Incidence of other clinical adverse events
New-onset atrial fibrillation, stroke, Upgrade to CRT, ICD, CRTD or HBP
Time frame: 6-month, 12-month, 24-month and 36-month follow-up
Plan to share: No
Started Jun 2021 (actual). Primary completion is estimated for Jan 2028, 79 months after the start.
Of 44 interventional studies with no phase under Atrioventricular Block, half reached primary completion within 33 months of starting (the median), counting those still running; a quarter within 18 and three quarters within 55. This study's planned 79 months is above that.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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The First Affiliated Hospital with Nanjing Medical University →