Breathing-linked pacemaker pacing after bypass surgery for heart failure with reduced ejection fraction

Respiratory Sinus Arrhythmia Pacing Post-CABG Surgery in Patients With HFrEF

Not applicable Interventional Ceryx Medical Ltd · NCT06384963

This will test a pacemaker setting that restores the heart's natural breathing-linked rate in people with reduced ejection fraction after bypass surgery to see if it is safe and improves heart function.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment54 (estimated)
Ages22 Years and up
SexAll
SponsorCeryx Medical Ltd Industry-sponsored
Locations3 sites (Adelaide, South Australia and 2 other locations)
Trial IDNCT06384963 on ClinicalTrials.gov

What this trial studies

This first-in-human, multicentre, randomized controlled trial compares respiratory sinus arrhythmia (RSA)–modulated atrial pacing to standard monotonic atrial pacing in patients with HFrEF undergoing on-pump CABG. Participants receive the assigned pacing for up to 10 days while monitored closely in hospital, with baseline testing before surgery and a phone follow-up at one month. The primary outcome is safety measured by arrhythmia episodes, and secondary outcomes include measures of cardiac function, cardiac output, and apnoea episodes. The trial aims to see whether restoring breathing-linked heart rate variability improves short-term postoperative cardiac performance without increasing risk.

Who should consider this trial

Good fit: Adults aged 22 or older with HFrEF (left ventricular EF 20–40%), in sinus rhythm, scheduled for isolated on-pump CABG including the left anterior descending artery, and able to give informed consent are the intended participants.

Not a fit: Patients with atrial fibrillation or flutter, an existing pacemaker or defibrillator, emergency or off-pump CABG, intrinsic resting heart rate over 100 bpm, pregnancy, or inability to consent are unlikely to benefit from this intervention.

Why it matters

Potential benefit: If successful, RSA pacing could improve cardiac output and short-term recovery after CABG for people with HFrEF while maintaining typical pacemaker safety.

How similar studies have performed: This is a first-in-human test of RSA pacing: animal studies suggested improved cardiac function but human data are currently lacking.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adult patients (≥ 22 years) selected for isolated, on-pump coronary artery bypass graft (CABG)
* Established diagnosis of heart failure with reduced ejection fraction (HFrEF).
* Elective or urgent admission routes
* Echocardiography assessment of left ventricular ejection fraction (EF) of 20%-40% (within 1 month of planned surgery)
* Sinus rhythm
* Any number of coronary vessels replaced. Must include left anterior descending artery.
* Able to provide written informed consent

Exclusion Criteria:

* Requirement for concurrent valve replacement surgery.
* Off-pump CABG.
* Emergency CABG
* History of paroxysmal or permanent atrial fibrillation or flutter
* History of atrioventricular-node dependent tachycardia
* Patients lacking capacity to consent
* Patient testing positive for Covid-19 within 14 days of intended CABG (PCR or lateral flow test)
* Intrinsic resting heart rate \> 100bpm
* Pregnancy
* Implanted pacemaker or defibrillator
* Failure to obtain Uscom signals

Where this trial is running

Adelaide, South Australia and 2 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Heart Failure With Reduced Ejection Fractionheart failurerespiratory sinus arrhythmiapacemaker
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.