Posterosuperior Bundle Pacing for Prevention of Atrial Fibrillation in Patients With Sinus Node Dysfunction (PSB-AF)

A Prospective, Multicenter, Randomized Controlled Trial Evaluating the Effect of Posterosuperior Bundle Pacing on Atrial Fibrillation Prevention in Patients With Sinus Node Dysfunction

This study aims to evaluate whether posterosuperior bundle (PSB) pacing reduces the incidence of atrial fibrillation (AF) in patients with sinus node dysfunction (SND) undergoing pacemaker implantation. Approximately 300 patients will be enrolled and randomized to receive atrial pacing at either the PSB region or the right atrial appendage (RAA). The primary endpoint is the occurrence of AF episodes lasting ≥6 minutes, as detected by device or surface electrocardiogram. Patients will be followed for up to 24 months.

Study Overview

• Status: Not yet recruiting
• Conditions: Cardiac Pacing; Pacing Therapy
• Intervention / Treatment: Procedure: PSB pacing; Procedure: RAA pacing

Detailed Description

Sinus node dysfunction (SND) is a common indication for permanent pacemaker implantation. Conventional right atrial appendage (RAA) pacing may result in delayed or dyssynchronous atrial activation, potentially increasing the risk of atrial arrhythmias. Posterosuperior bundle (PSB) pacing is a novel physiological atrial pacing approach. This study is a prospective, multicenter, open-label, randomized controlled trial. A total of approximately 300 eligible SND patients indicated for pacemaker implantation will be enrolled and randomly assigned (1:1) to PSB pacing or RAA pacing. Ventricular pacing will be performed using left bundle branch area pacing in both groups. Participants will be followed at 3, 6, 12, and 24 months after implantation. An interim analysis will be conducted after 100 patients complete the 6-month follow-up.

The primary endpoint is the occurrence of AF episodes lasting ≥6 minutes. Secondary endpoints include atrial high-rate episodes, AF burden, pacing parameters, ECG and echocardiographic indices, laboratory findings, and mortality outcomes. Safety endpoints include procedural complications and device-related adverse events.

• Study Type: Interventional
• Enrollment (Estimated): 300
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Zhaohui Qiu; Phone Number: +862152039999; Email: qzh3503@shtrhospital.com

Study Locations

• China
  • Anhui
    • Anqing, Anhui, China
      • China Medical University affiliated AnQing Municipal Hospital
      • Contact: Liangchuan Chen; Phone Number: +86 13956556381; Email: aqslyy@163.com
    • Tongling, Anhui, China
      • Tongling People's Hospital
      • Contact: Ying Zhang; Phone Number: +86 18005669636; Email: tlph@mail.wh.ah.cn
  • Guizhou
    • Zunyi, Guizhou, China
      • Affiliated Hospital of Zunyi Medical College
      • Contact: Xianping Long; Phone Number: +86 13885294999; Email: longxianping1201@163.com
  • Hubei
    • Wuhan, Hubei, China
      • Wuhan Asia General Hospital
      • Contact: Hongwei Han; Phone Number: +86 15327298622; Email: wuhanagh@163.com
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200336
      • Tong Ren Hospital, Shanghai Jiaotong University School of Medicine
      • Contact: Zhaohui Qiu; Phone Number: +862152039999; Email: qzh3503@shtrhospital.com
    • Shanghai, Shanghai Municipality, China
      • Fudan University affiliated Huadong Hospital
      • Contact: Zhengqi Kong; Phone Number: +86 13816620347; Email: huadongtexu@163.com
    • Shanghai, Shanghai Municipality, China
      • Shanghai Jiaotong University affiliated Shanghai Ninth People's Hospital
      • Contact: Zongqi Zhang; Phone Number: +86 18049827281; Email: zqzhang_scdc@126.com
    • Shanghai, Shanghai Municipality, China
      • Shanghai Jiaotong University affiliated Shanghai Sixth People's Hospital
      • Contact: Yisheng Pan; Phone Number: +86 13817273883; Email: shlygjyl@163.com
    • Shanghai, Shanghai Municipality, China
      • Shanghai University of Traditional Chinese Medicine affiliated Putuo Hospital
      • Contact: Zongjun Liu; Phone Number: +86 19821577439; Email: lzj72@126.com
    • Shanghai, Shanghai Municipality, China
      • Tongji University School of Medicine affiliated Tongji University
      • Contact: Bing Sun; Phone Number: +86 13918324334; Email: woowoocncn@163.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age ≥18 years
• Indication for permanent pacemaker implantation, including:
• Sinus node dysfunction, defined as at least one of the following:
• Symptomatic sinus bradycardia
• Tachy-brady syndrome
• Chronotropic incompetence
• Sinus pause / arrest
• Atrioventricular block (if present); if ventricular pacing is required, left bundle branch area pacing is planned
• Expected survival >1 year
• Panned implantation of a device capable of detecting atrial high-rate episodes
• Willing and able to provide informed consent

Exclusion Criteria:

• Persistent atrial fibrillation (AF) (>7 days), long-standing persistent AF, permanent AF, or prior atrioventricular node ablation
• Prior cardiac implantable electronic device (CIED) requiring replacement, upgrade, or revision
• Indication for cardioverter-defibrillator (ICD) or cardiac resynchronization therapy (CRT-D)
• Prior cardiac surgery, severe hepatic or renal dysfunction, or other life-threatening systemic diseases
• Acute myocardial infarction within 3 months before enrollment
• Persistent left superior vena cava or dextrocardia
• Pregnant or breastfeeding women, or women of childbearing potential not using effective contraception
• Participation in another clinical trial that may interfere
• Any condition that, in the opinion of the investigator, makes participation unsuitable

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PSB pacing; Patients were randomly assigned to receive posterosuperior bundle pacing for atrial pacing during regular pacemaker implantation procedures.	Procedure: PSB pacing; Atrial pacing lead implanted at the posterosuperior bundle region. Left bundle branch area pacing will be applied if ventricular pacing is necessary.
Active Comparator: RAA pacing; Patients were randomly assigned to receive right atrial appendage pacing for atrial pacing during regular pacemaker implantation procedures.	Procedure: RAA pacing; Atrial pacing lead implanted at the right atrial appendage. Left bundle branch area pacing will be applied if ventricular pacing is necessary.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of atrial fibrillation	Incidence of atrial fibrillation ≥ 6 minutes during follow-ups	From implantation to regular follow-ups up to 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Atrial high-rate episodes		From implantation to regular follow-ups up to 24 months
AF burden		From implantation to regular follow-ups up to 24 months
Intrinsic P-wave duration	Measured from the onset of the P wave to the end	At baseline and regular follow-ups up to 24 months, when intrinsic atrial rhythm is assessable
Paced P-wave duration	Measured from the pacing stimulus to P wave end duration	From implantation to regular follow-ups up to 24 months
Left ventricular ejection fraction (LVEF)	Standard transthoracic echocardiographic parameter	At baseline, 6-, 12-, and 24-month follow-ups
Left atrial diameter (LAD)	Standard transthoracic echocardiographic parameter	At baseline, 6-, 12-, and 24-month follow-ups
Right atrial diameter (RAD)	Standard transthoracic echocardiographic parameter	At baseline, 6-, 12-, and 24-month follow-ups
Left ventricular end-systolic diameter (LVESD)	Standard transthoracic echocardiographic parameter	At baseline, 6-, 12-, and 24-month follow-ups
Left ventricular end-diastolic diameter （LVEDD）	Standard transthoracic echocardiographic parameter	At baseline, 6-, 12-, and 24-month follow-ups
E/e'	Standard transthoracic echocardiographic parameter	At baseline, 6-, 12- , 24-month follow-ups
Mitral regurgitation severity	Standard transthoracic echocardiographic measurement using standard semi-quantitative grading (none/trace, mild, moderate, or severe)	At baseline, 6-, 12- , 24-month follow ups
Tricuspid regurgitation severity	Standard transthoracic echocardiographic measurement using standard semi-quantitative grading (none/trace, mild, moderate, or severe)	At baseline, 6-, 12-, 24- month follow-ups
NT-pro BNP	Standard transthoracic echocardiographic parameter	At baseline, before discharge, and 6-month follow-up
eGFR		At baseline, before discharge, and 6 - month follow-up
All-cause mortality		From implantation to regular follow-ups up to 24 months
Cardiovascular death		From implantation to regular follow-ups up to 24 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Procedural complications	Safety Outcome	Perioperative
Postoperative adverse events	Safety Outcome, including lead-related complications, thromboembolic events, etc.	From implantation to regular follow-ups up to 24 months
Atrial pacing capture threshold		From implantation to regular follow-ups up to 24 months
Atrial sensing amplitude		From implantation to regular follow-ups up to 24 months
Atrial pacing output		From implantation to regular follow-ups up to 24 months
Paced P-wave morphology	positive, negative, notched, and biphasic	From implantation to regular follow-ups up to 24 months
Intrinsic P-wave morphology	positive, negative, notched, and biphasic	At baseline, implant, and regular follow-ups up to 24 months when intrinsic atrial rhythm is assessable

Collaborators and Investigators

• Sponsor: Shanghai Tong Ren Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): February 1, 2029
• Study Completion (Estimated): February 1, 2029

Study Registration Dates

• First Submitted: May 18, 2026
• First Submitted That Met QC Criteria: June 8, 2026
• First Posted (Actual): June 12, 2026

Study Record Updates

• Last Update Posted (Actual): June 12, 2026
• Last Update Submitted That Met QC Criteria: June 8, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: atrial pacing; Physiological pacing; Posterosuperior bundle pacing; Right atrial appendage pacing
• Other Study ID Numbers: PSB-AF

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