RecruitingNot Applicable

BIO|STREAM.CSP CLS

Czechia, Hungary, Italy150 participantsStarted 2026-05-29

Plain-language summary

This clinical study is a prospective, observational submodule of the BIO\|STREAM.CSP registry designed to evaluate clinical outcomes in patients receiving BIOTRONIK dual-chamber pacemakers that combine conduction system pacing-specifically left bundle branch area pacing (LBBAP)-with Closed Loop Stimulation (CLS). The purpose of the study is to better understand how this combined pacing strategy performs in routine clinical practice and whether it may help reduce the occurrence of atrial fibrillation in patients with sinus node dysfunction (SND) and concomitant atrioventricular (AV) conduction disorders. The primary question the study seeks to answer is what the incidence of device-detected atrial fibrillation (DDAF) is over a 24-month follow-up period in patients treated with LBBAP and active CLS. Additionally, the study explores how CLS dynamically modulates pacing rates when the ventricular lead is positioned within the conduction system, and whether this physiological pacing approach may mitigate the negative effects associated with conventional right ventricular pacing. Overall, this study aims to generate real-world evidence to support optimization of pacemaker programming and to inform clinical decision-making regarding the use of CLS in combination with conduction system pacing, with the goal of improving patient outcomes and reducing atrial arrhythmia burden.

Who can participate

Age range

18 Years – 18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Enrolled in the BIO\|STREAM.CSP registry * Standard indication for dual-chamber pacing due to any form of sinus node disease according to guidelines * DDD-CLS pacing mode activated * Either ≥ II degree AV block, or native PR interval ≥ 200 ms at baseline ECG with expected RVP ≥ 20% Exclusion Criteria: * Implantation dates back more than 90 days * History of clinical AF * Patients intended to receive, or already received a pacing lead for traditional RV pacing, His bundle pacing or right bundle branch pacing * Upgrade from previous pacemaker system * Patients transitioning from the BIO\|MASTER.CSP study * DDAF episodes present in the device memory at the time of registration

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

DDAF incidence

Timeframe: From CLS activation to 24 months after implantation

DDAF burden

Timeframe: From CLS activation to 24 months after implantation

Heart Rate histograms

Timeframe: At 1 year and 2 years after implantation

Trial details

NCT IDNCT07608822

SponsorBiotronik SE & Co. KG

Sponsor typeINDUSTRY

Study typeOBSERVATIONAL

Primary completion2028-05-29

Contact for this trial

Martina Del Maestro

+393426529214 CLS-CSP-STREAM@biotronik.com

View on ClinicalTrials.gov More Sinus Node Disease trials