Prospective Cohort Study of Bachmann Bundle Versus Right Atrial Appendage Pacing: Impact on Atrial Cardiomyopathy Evaluated by Echocardiographic Parameters and Clinical Outcome

Overview

The goal of this observational study is to evaluate the impact of different atrial pacing sites-Bachmann's bundle pacing versus right atrial appendage pacing-on the development and progression of atrial cardiomyopathy in patients diagnosed with sick sinus syndrome who are undergoing permanent pacemaker implantation.

Detailed description

Previous studies have reported that conventional Right Atrial Appendage pacing is associated with delayed atrial activation time. A higher burden of atrial pacing at this site has been linked to an increased incidence of atrial fibrillation and atrial tachycardia. Furthermore, structural and functional deterioration of the atria-specifically Left Atrial dilation and reduced left atrial strain-has been observed in patients with a high percentage of Right Atrial Appendage pacing. These changes are known to accelerate the progression of atrial cardiomyopathy, potentially leading to adverse long-term clinical outcomes.

To address these limitations, Bachmann Bundle Pacing has emerged as a promising alternative pacing site. The Bachmann bundle is a major atrial myoarchitecture connecting the right and left atria. Pacing at this site is expected to facilitate interatrial conduction, thereby restoring interatrial synchrony and mitigating interatrial block. Prior research indicates that pacing at the Bachmann bundle is associated with a reduced incidence of atrial fibrillation and atrial tachycardia, suggesting distinct benefits regarding atrial electrophysiological outcomes. However, existing studies have primarily focused on electrophysiological parameters, such as arrhythmia incidence. Consequently, the impact of Bachmann Bundle Pacing on atrial structural and functional remodeling remains to be clearly elucidated.

Therefore, this study is designed as a single-center cohort study enrolling a total of 200 subjects (100 prospective and 100 retrospective). The investigators will analyze echocardiographic parameters over a 12-month period following pacemaker implantation. By comprehensively analyzing imaging parameters (left atrial/right atrial strain and volume changes assessed via echocardiography) and clinical outcomes (atrial arrhythmias, heart failure hospitalization, and mortality), this study aims to investigate the differential effects of Bachmann Bundle Pacing versus Right Atrial Appendage pacing on the development and progression of atrial cardiomyopathy.

Interventions

• Procedure Right Atrial Appendage Pacing
  Atrial lead positioned in the right atrial appendage
• Procedure Bachmann Bundle Pacing
  Atrial lead positioned in the bachmann bundle branch

Primary outcome measures

• Structural echocardiographic parameters of the left atrium [Time frame: 6 and 12 months after pacemaker implantation]
• Functional echocardiographic parameters of the left atrium [Time frame: 6 and 12 months after pacemaker implantation]

Secondary outcome measures (12)

• Structural echocardiographic parameters of the left ventricle [Time frame: 6 and 12 months after pacemaker implantation]
• Functional echocardiographic parameters of the left ventricle [Time frame: 6 and 12 months after pacemaker implantation]
• Mitral and tricuspid regurgitation volume [Time frame: 6 and 12 months after pacemaker implantation]
• Structural echocardiographic parameters of the right atrium [Time frame: 6 and 12 months after pacemaker implantation]
• Functional echocardiographic parameters of the right atrium [Time frame: 6 and 12 months after pacemaker implantation]
• ECG parameters [Time frame: 6 and 12 months after pacemaker implantation]
• Average heart rate [Time frame: 6 and 12 months after pacemaker implantation]
• Heart rate distribution [Time frame: 6 and 12 months after pacemaker implantation]
• Pacing burden [Time frame: 6 and 12 months after pacemaker implantation]
• Atrial fibrillation burden [Time frame: 6 and 12 months after pacemaker implantation]
• atrial fibrillation occurrence [Time frame: 6 and 12 months after pacemaker implantation]
• NTproBNP [Time frame: 6 and 12 months after pacemaker implantation]

Eligibility criteria

Inclusion criteria

• Patients aged 19 years or older
• Patients diagnosed with sick sinus syndrome who are scheduled for de novo implantation of a permanent pacemaker or permanent implantable cardioverter-defibrillator
• Patients or their legal representatives who voluntarily consent to the access of medical records and study data throughout the entire research period

Exclusion criteria

• Patients with persistent or permanent AF
• Patients with a life expectancy of less than one year due to other comorbidities
• Pregnant or breastfeeding women
• Patients who refuse active treatment

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

South Korea · 1 center

• Samsung Medical Center — Seoul

Publications

• Bailin SJ, Adler S, Giudici M. Prevention of chronic atrial fibrillation by pacing in the region of Bachmann's bundle: results of a multicenter randomized trial. J Cardiovasc Electrophysiol. 2001 Aug;12(8):912-7. doi: 10.1046/j.1540-8167.2001.00912.x. PMID 11513442
• Infeld M, Nicoli CD, Meagher S, Tompkins BJ, Wayne S, Irvine B, Betageri O, Habel N, Till S, Lobel J, Meyer M, Lustgarten DL. Clinical impact of Bachmann's bundle pacing defined by electrocardiographic criteria on atrial arrhythmia outcomes. Europace. 2022 Oct 13;24(9):1460-1468. doi: 10.1093/europace/euac029. PMID 35304608
• Lustgarten DL, Habel N, Sanchez-Quintana D, Winget J, Correa de Sa D, Lobel R, Thompson N, Infeld M, Meyer M. Bachmann bundle pacing. Heart Rhythm. 2024 Sep;21(9):1711-1717. doi: 10.1016/j.hrthm.2024.03.1786. Epub 2024 Mar 27. No abstract available. PMID 38552731
• Martens P, Deferm S, Bertrand PB, Verbrugge FH, Ramaekers J, Verhaert D, Dupont M, Vandervoort PM, Mullens W. The Detrimental Effect of RA Pacing on LA Function and Clinical Outcome in Cardiac Resynchronization Therapy. JACC Cardiovasc Imaging. 2020 Apr;13(4):895-906. doi: 10.1016/j.jcmg.2019.04.022. Epub 2019 Jul 17. PMID 31326478
• Roithinger FX, Abou-Harb M, Pachinger O, Hintringer F. The effect of the atrial pacing site on the total atrial activation time. Pacing Clin Electrophysiol. 2001 Mar;24(3):316-22. doi: 10.1046/j.1460-9592.2001.00316.x. PMID 11310300
• De Sisti A, Leclercq JF, Stiubei M, Fiorello P, Halimi F, Attuel P. P wave duration and morphology predict atrial fibrillation recurrence in patients with sinus node dysfunction and atrial-based pacemaker. Pacing Clin Electrophysiol. 2002 Nov;25(11):1546-54. doi: 10.1046/j.1460-9592.2002.01546.x. PMID 12494610
• Elkayam LU, Koehler JL, Sheldon TJ, Glotzer TV, Rosenthal LS, Lamas GA. The influence of atrial and ventricular pacing on the incidence of atrial fibrillation: a meta-analysis. Pacing Clin Electrophysiol. 2011 Dec;34(12):1593-9. doi: 10.1111/j.1540-8159.2011.03192.x. Epub 2011 Aug 7. PMID 21819434
• Bradshaw PJ, Stobie P, Knuiman MW, Briffa TG, Hobbs MS. Trends in the incidence and prevalence of cardiac pacemaker insertions in an ageing population. Open Heart. 2014 Dec 10;1(1):e000177. doi: 10.1136/openhrt-2014-000177. eCollection 2014. PMID 25512875

Identifiers

NCT: NCT07360067 · SMC2025-10-106 · KCT0011382

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗