Heart Failure With Reduced Ejection FractionRSA-PACENCT06359938
Respiratory Sinus Arrhythmia (RSA) Pacing Post-CABG Surgery in Patients With HFrEF
A study testing Atrial pacing with respiratory sinus arrhythmia (RSA) variability and Monotonic right atrial overdrive pacing in people with Heart Failure With Reduced Ejection Fraction, run by Ceryx Medical Ltd at 1 site in United Kingdom.
Trial summary
The goal of this clinical trial is to test a new type of pacemaker in heart failure patients following a heart bypass operation. The new pacemaker restores respiratory sinus arrhythmia which is a natural pattern where the heart rate increases when the participants breathe in and slows down when participants breathe… Read more about this study
- Who is it for?
- Ages 22 years and older
- Conditions the study is for
- Heart Failure With Reduced Ejection Fraction
- What is being tested?
- Atrial pacing with respiratory sinus arrhythmia (RSA) variability and Monotonic right atrial overdrive pacing
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 22 Nov 2024to 31 Jul 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 22 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Show all 11Show fewer
- 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
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Cardiff & Vale University Health Board
Cardiff, Cardiff, CF14 4XW
About this study
Official title: Respiratory Sinus Arrhythmia Pacing Post-CABG Surgery in Patients With HFrEF
The goal of this clinical trial is to test a new type of pacemaker in heart failure patients following a heart bypass operation. The new pacemaker restores respiratory sinus arrhythmia which is a natural pattern where the heart rate increases when the participants breathe in and slows down when participants breathe out.
The main questions the trial aims to answer are:
Read more
- Is the new type of pacemaker safe?
- Does the new type of pacemaker improve how patients' hearts work (also known as cardiac output)?
Participants will have a range of tests before their operation and during their recovery in hospital while participants have the new type of pacemaker in place, and will be monitored very closely. Participants will also receive a phone call 1 month after their surgery. Researchers will compare the new type of heart pacing against standard treatment to see if it is as safe, and if it is any better for patients.
Read the detailed description
This is a first-in-human (FIH) clinical investigation of a modification of an existing medical device. It will be a comparative, multicentre, randomised controlled trial (RCT) design. RSA modulated atrial pacing will be compared against monotonic atrial pacing in patients with HFrEF who have had CABG surgery.
The purpose of this clinical investigation is to explore the risk/benefit profile of the use of RSA pacing in patients with HFrEF following CABG. Based on the prior animal models the investigators hypothesise an improvement in cardiac function over several days of RSA pacing, with no increase in risk compared to typical pacemaker use.
Primary hypothesis - Atrial pacing with additional RSA variability (for up to 10 days) is feasible and safe in patients with heart failure and reduced ejection fraction. The primary outcome is measuring arrhythmia episodes.
Secondary hypothesis - Atrial pacing with additional RSA variability improves cardiac function in patients with heart failure and reduced ejection fraction following CABG surgery. The secondary outcomes is measuring cardiac function, cardiac output, apnoea episodes.
Respiratory sinus arrhythmia is part of normal physiology and RSA pacing is looking to restore this. In heart failure, RSA is severely reduced. Therefore the investigators have identified that, post-CABG surgery patients with heart failure and reduced ejection fraction are the ideal candidates for this study. Following surgery it is standard of care for a surgeon to leave temporary pacing wires attached to the heart as a precaution and it is not uncommon to leave them in for 10 days or longer. Hence, these temporary wires can be used to deliver RSA pacing. Adjusting pacing rates is common in both implanted or temporary pacemakers.
Potential patients awaiting CABG surgery with heart failure with reduced ejection fraction will be identified using two routes - inpatients and outpatients.
The investigators would randomly allocate patients to either the RSA external pacemaker box or the normal external pacemaker for a maximum of 10 days. Patients will be connected to nasal prongs to monitor their respiration and in the RSA group, this signal will be fed to the external pacemaker to deliver RSA pacing.
- Being tested
- Atrial pacing with respiratory sinus arrhythmia (RSA) variability, Monotonic right atrial overdrive pacing
- Keywords
- heart failure, respiratory sinus arrhythmia, pacemaker
- Medical subject headings
- Heart Failure, Arrhythmia, Sinus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Atrial pacing with respiratory sinus arrhythmia (RSA) variabilityDevice
Also called Modified temporary external pacemaker (Osypka) with additional pacing RSA module (Ceryx box)
The intervention in this study is a modification of the pacing output from a standard external pacemaker such that it will approximate the RSA variation found in healthy subjects. A pacemaker (PACE204, Osypka Medical AG), similar to those currently in common use in post-CABG patients, will be adapted to receive an additional input signal based on the respiratory signal (Ceryx device). The respiration signal will be combined with the ECG signal to determine the appropriate pacing interval. The pacing impulse will be delivered by the pacemaker unit.
Monotonic right atrial overdrive pacingDevice
Also called PACE204 pacemaker (Osypka Medical AG) delivering standard monotonic right atrial pacing
Pacing is delivered by a PACE204 pacemaker (Osypka Medical AG) delivering standard monotonic right atrial pacing
| Study group | Role | What they receive |
|---|---|---|
| Atrial pacing with respiratory sinus arrhythmia (RSA) variability | Experimental | The experimental arm is atrial pacing with additional respiratory sinus arrhythmia (RSA) modulation following coronary artery bypass graft (CABG) surgery. Pacing impulses will be grouped together during inspiration, such that heart rate (HR) will increase by approximately 6 bpm above median during inspiration, and decrease by around 6 bpm below median during expiration. Five pacing rates will be used to accommodate a range of patients' intrinsic HR.
Pacing will be initiated after randomisation, after the patient is removed from ventilator support (Pacing Day 1, PD1). This is usually the day after surgery. Pacing will continue until the patient is ready for discharge or there is a clinical decision to stop pacing and remove the leads (whichever is soonest).
Pacing is delivered by a PACE204 pacemaker (Osypka Medical AG) modulated to respiratory phase by a Ceryx device (intervention) Receives: Device: Atrial pacing with respiratory sinus arrhythmia (RSA) variability |
| Monotonic atrial pacing | Active comparator | The control arm is standard monotonic right atrial pacing at the relevant median rate following coronary artery bypass graft (CABG) surgery. Pacing will be initiated after randomisation, after the patient is removed from ventilator support (Pacing Day 1, PD1). This is usually the day after surgery. Pacing will continue until the patient is ready for discharge or there is a clinical decision to stop pacing and remove the leads (whichever is soonest).
Pacing is delivered by a PACE204 pacemaker (Osypka Medical AG) delivering standard monotonic right atrial pacing. Receives: Device: Monotonic right atrial overdrive pacing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of arrhythmia episodes per patient during pacing
Any episode of arrhythmia, captured on an ECG between the initiation of pacing (Pacing Day 1) and the post-pacing visit (Day 7 - Post-discharge form hospital ), and lasting 30 seconds or longer, will be recorded. Anonymised ECG extracts will be reviewed by two cardiologists to identify the type of arrhythmia.
Measured: From start of pacing to end of pacing
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Apr 2024
- Study start22 Nov 2024
- Primary completion31 Jul 2026
- Study completion31 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Heart Failure With Reduced Ejection FractionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ceryx Medical Ltd
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Cardiff and Vale University Health Board
- Responsible party
- Sponsor
- Investigators
- Zaheer Yousef, Principal investigator, Cardiff and Vale University Health Board
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06359938
- Sponsor's protocol ID
- Cer22/01
- Acronym
- RSA-PACE
- Status last verified
- Apr 2026
- First submitted
- 14 Mar 2023
- Last updated
- 5 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Respiratory Sinus Arrhythmia Pacing Post-CABG Surgery in Patients With HFrEF
- ClinicalTrials.gov ID
- NCT06359938
- Acronym / sponsor ID
- RSA-PACE / Cer22/01
- Keywords
- heart failure, respiratory sinus arrhythmia, pacemaker
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Ceryx Medical LtdIndustry (pharma, biotech, devices)
- Collaborators
- Cardiff and Vale University Health Board
- Study start
- 22 Nov 2024 (actual)
- Primary completion
- 31 Jul 2026 (actual)
- Study completion
- 31 Jul 2026 (actual)
- First posted
- 11 Apr 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to test a new type of pacemaker in heart failure patients following a heart bypass operation. The new pacemaker restores respiratory sinus arrhythmia which is a natural pattern where the heart rate increases when the participants breathe in and slows down when participants breathe out.
The main questions the trial aims to answer are:
- Is the new type of pacemaker safe?
- Does the new type of pacemaker improve how patients' hearts work (also known as cardiac output)?
Participants will have a range of tests before their operation and during their recovery in hospital while participants have the new type of pacemaker in place, and will be monitored very closely. Participants will also receive a phone call 1 month after their surgery. Researchers will compare the new type of heart pacing against standard treatment to see if it is as safe, and if it is any better for patients.
Detailed description
This is a first-in-human (FIH) clinical investigation of a modification of an existing medical device. It will be a comparative, multicentre, randomised controlled trial (RCT) design. RSA modulated atrial pacing will be compared against monotonic atrial pacing in patients with HFrEF who have had CABG surgery.
The purpose of this clinical investigation is to explore the risk/benefit profile of the use of RSA pacing in patients with HFrEF following CABG. Based on the prior animal models the investigators hypothesise an improvement in cardiac function over several days of RSA pacing, with no increase in risk compared to typical pacemaker use.
Primary hypothesis - Atrial pacing with additional RSA variability (for up to 10 days) is feasible and safe in patients with heart failure and reduced ejection fraction. The primary outcome is measuring arrhythmia episodes.
Secondary hypothesis - Atrial pacing with additional RSA variability improves cardiac function in patients with heart failure and reduced ejection fraction following CABG surgery. The secondary outcomes is measuring cardiac function, cardiac output, apnoea episodes.
Respiratory sinus arrhythmia is part of normal physiology and RSA pacing is looking to restore this. In heart failure, RSA is severely reduced. Therefore the investigators have identified that, post-CABG surgery patients with heart failure and reduced ejection fraction are the ideal candidates for this study. Following surgery it is standard of care for a surgeon to leave temporary pacing wires attached to the heart as a precaution and it is not uncommon to leave them in for 10 days or longer. Hence, these temporary wires can be used to deliver RSA pacing. Adjusting pacing rates is common in both implanted or temporary pacemakers.
Potential patients awaiting CABG surgery with heart failure with reduced ejection fraction will be identified using two routes - inpatients and outpatients.
The investigators would randomly allocate patients to either the RSA external pacemaker box or the normal external pacemaker for a maximum of 10 days. Patients will be connected to nasal prongs to monitor their respiration and in the RSA group, this signal will be fed to the external pacemaker to deliver RSA pacing.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Atrial pacing with respiratory sinus arrhythmia (RSA) variability | Experimental | Device: Atrial pacing with respiratory sinus arrhythmia (RSA) variabilityThe experimental arm is atrial pacing with additional respiratory sinus arrhythmia (RSA) modulation following coronary artery bypass graft (CABG) surgery. Pacing impulses will be grouped together during inspiration, such that heart rate (HR) will increase by approximately 6 bpm above median during inspiration, and decrease by around 6 bpm below median during expiration. Five pacing rates will be used to accommodate a range of patients' intrinsic HR. Pacing will be initiated after randomisation, after the patient is removed from ventilator support (Pacing Day 1, PD1). This is usually the day after surgery. Pacing will continue until the patient is ready for discharge or there is a clinical decision to stop pacing and remove the leads (whichever is soonest). Pacing is delivered by a PACE204 pacemaker (Osypka Medical AG) modulated to respiratory phase by a Ceryx device (intervention) |
| Monotonic atrial pacing | Active comparator | Device: Monotonic right atrial overdrive pacingThe control arm is standard monotonic right atrial pacing at the relevant median rate following coronary artery bypass graft (CABG) surgery. Pacing will be initiated after randomisation, after the patient is removed from ventilator support (Pacing Day 1, PD1). This is usually the day after surgery. Pacing will continue until the patient is ready for discharge or there is a clinical decision to stop pacing and remove the leads (whichever is soonest). Pacing is delivered by a PACE204 pacemaker (Osypka Medical AG) delivering standard monotonic right atrial pacing. |
Who may qualify
- Ages
- 22 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- 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
Key exclusion criteria (11 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Atrial pacing with respiratory sinus arrhythmia (RSA) variabilityAlso: Modified temporary external pacemaker (Osypka) with additional pacing RSA module (Ceryx box)The intervention in this study is a modification of the pacing output from a standard external pacemaker such that it will approximate the RSA variation found in healthy subjects. A pacemaker (PACE204, Osypka Medical AG), similar to those currently in common use in post-CABG patients, will be adapted to receive an additional input signal based on the respiratory signal (Ceryx device). The respiration signal will be combined with the ECG signal to determine the appropriate pacing interval. The pacing impulse will be delivered by the pacemaker unit. | Device | Atrial pacing with respiratory sinus arrhythmia (RSA) variability |
| Monotonic right atrial overdrive pacingAlso: PACE204 pacemaker (Osypka Medical AG) delivering standard monotonic right atrial pacingPacing is delivered by a PACE204 pacemaker (Osypka Medical AG) delivering standard monotonic right atrial pacing | Device | Monotonic atrial pacing |
Primary outcome
Number of arrhythmia episodes per patient during pacing
Time frame: From start of pacing to end of pacing
Any episode of arrhythmia, captured on an ECG between the initiation of pacing (Pacing Day 1) and the post-pacing visit (Day 7 - Post-discharge form hospital ), and lasting 30 seconds or longer, will be recorded. Anonymised ECG extracts will be reviewed by two cardiologists to identify the type of arrhythmia.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Zaheer Yousef principal investigator
Cardiff and Vale University Health Board
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Atrial pacing with respiratory sinus arrhythmia (RSA) variability and Monotonic right atrial overdrive pacing in people with Heart Failure With Reduced Ejection Fraction, run by Ceryx Medical Ltd at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of arrhythmia episodes per patient during pacing (time frame: From start of pacing to end of pacing). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Aug 2026; AzTrials last refreshed its copy on 6 Nov 2026.