Atrial FibrillationSAFE-CMAPNCT07820631
First-in-Human Study of the Circle Safe System for Diaphragm Response Monitoring During Pulmonary Vein Ablation
A study testing Circle Safe System Use During Pulmonary Vein Ablation in people with Atrial Fibrillation, run by Circle Safe, Inc. at 4 sites in 2 countries.
Trial summary
The objective of this first-in-human study is to evaluate the safety and performance of the Circle Safe System in subjects undergoing pulmonary vein ablation for atrial fibrillation. Read more about this study
- Who is it for?
- Ages 19 to 84 years
- Conditions the study is for
- Atrial Fibrillation
- What is being tested?
- Circle Safe System Use During Pulmonary Vein Ablation
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 4 sitesin 2 countries
- Study dates
- 17 Aug 2026to 31 Oct 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 19 to 84 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male or females >18 and ≤ 85 years of age
- Subject willing to sign informed consent
- Subject is a candidate for pulmonary vein ablation for the treatment of atrial fibrillation ablation procedures therapy
Who cannot join
- Subjects with pacemaker or defibrillator leads placed through the vena cava
- Subjects with implantable vena cava filter
- Subjects with a contraindication to contrast dye
- Pregnant subjects
- Subjects with inadequate venous access due to prior vein thrombosis or indwelling chronic ports or catheters
- Subjects participating in another clinical trial that has not reached the follow-up time point to primary endpoint assessment
- Subjects with known neuromuscular disease or other medical history (i.e trauma, surgery) that could have impacted diaphragmatic function
Trial locations and contacts
4 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
4 sites in 2 countries
France3 sites
CHU Timone - APHM
Marseille, 13005
Hôpital Cardiologique du Haut Lévèque
Pessac, 33604
Clinique Pasteur
Toulouse, 31300
About this study
Official title: Evaluation of the Safety and Effectiveness of the Circle SAFE System for Diaphragmatic Compound Motor Action Potential (CMAP) Recording and Display of Patients Undergoing Pulmonary Vein Ablation Procedures. The SAFE-CMAP Clinical Trial
The objective of this first-in-human study is to evaluate the safety and performance of the Circle Safe System in subjects undergoing pulmonary vein ablation for atrial fibrillation.
The main questions it aims to answer are:
Read more
- Can the Circle Safe System consistently stimulate the phrenic nerve and record a stable electrical response from the diaphragm?
- Can it reliably display changes in the diaphragm's response during ablation?
- What device-related or procedure-related medical problems occur during the study? There is no comparison group. All participants will undergo their planned pulmonary vein ablation while the Circle Safe System is used during treatment of the right pulmonary veins.
Participants will:
- Complete standard assessments before the procedure
- Have the Circle Safe catheter placed in the superior vena cava during the ablation procedure
- Have their phrenic nerve stimulated and their diaphragm response monitored using the Circle Safe System
- Be evaluated for device-related and procedure-related safety events through hospital discharge
Read the detailed description
During right pulmonary vein ablation, the Circle Safe catheter is advanced through the venous system and positioned in the superior vena cava. Its distal electrodes provide diagnostic stimulation of the right phrenic nerve, while its proximal electrodes record the resulting diaphragmatic compound motor action potential (CMAP).
The recorded signal is transmitted to the Circle Safe System Console, which displays the CMAP waveform and automatically compares its amplitude with a baseline measurement obtained before ablation. This allows changes in diaphragmatic activity to be monitored throughout treatment of the right pulmonary veins.
The Circle Safe System is a diagnostic monitoring aid. It does not deliver ablation energy, modify the ablation procedure, or replace standard phrenic nerve monitoring methods used by the physician. Device function, signal stability, procedural use, and any device deficiencies or adverse events are documented during the study.
- Conditions
- Atrial Fibrillation
- Being tested
- Circle Safe System Use During Pulmonary Vein Ablation
- Keywords
- Pulmonary vein ablation procedures, Phrenic Nerve Monitoring, Diaphragmatic CMAP Monitoring, CMAP Monitoring System
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Circle Safe System Use During Pulmonary Vein AblationDevice
The Circle Safe System will be used during ablation of the right pulmonary veins to stimulate the right phrenic nerve and record and display the resulting diaphragmatic compound motor action potential.
| Study group | Role | What they receive |
|---|---|---|
| Circle Safe System During Pulmonary Vein Ablation | Experimental | Participant will undergo pulmonary vein ablation while the Circle Safe System stimulates the right phrenic nerve Receives: Device: Circle Safe System Use During Pulmonary Vein Ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Freedom from device-related Major Adverse Events (MAEs) through hospital discharge. MAEs are defined as major thromboembolic events, vascular damage requiring surgical intervention, tamponade, perforation and ischemic stroke attributable to the device
Proportion of subjects free from device-related Major Adverse Events (MAEs) through hospital discharge. MAEs are defined as major thromboembolic events, vascular damage requiring surgical intervention, tamponade, perforation, and ischemic stroke attributable to the Circle Safe System.
Measured: Through index discharge, an average of 24 hours
Primary Effectiveness Endpoint: Successful Recording and Display of Diaphragmatic Compound Motor Action Potential (CMAP) by the Circle Safe System
Ability of the Circle Safe System to record and display diaphragmatic compound motor action potential (CMAP) of patients undergoing pulmonary vein ablation procedures. Successful CMAP recordings are defined as:
- The phrenic nerve can be captured consistently
- A large, stable diaphragmatic CMAP baseline is recorded
- Changes in amplitude can be tracked reliably throughout the ablation
Measured: Periprocedural
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Sep 2026
- Study start17 Aug 2026 (estimated)
- Primary completion31 Oct 2026 (estimated)
- Study completion31 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atrial FibrillationStudies 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
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Circle Safe, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Stéphane COMBES, MD, Principal investigator, Clinique Pasteur - Toulouse - FRANCE
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07820631
- Sponsor's protocol ID
- CP1131
- Acronym
- SAFE-CMAP
- Status last verified
- Sep 2026
- First submitted
- 22 Jul 2026
- Last updated
- 15 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Safety and Effectiveness of the Circle SAFE System for Diaphragmatic Compound Motor Action Potential (CMAP) Recording and Display of Patients Undergoing Pulmonary Vein Ablation Procedures. The SAFE-CMAP Clinical Trial
- ClinicalTrials.gov ID
- NCT07820631
- Acronym / sponsor ID
- SAFE-CMAP / CP1131
- Conditions
- Atrial Fibrillation
- Keywords
- Pulmonary vein ablation procedures, Phrenic Nerve Monitoring, Diaphragmatic CMAP Monitoring, CMAP Monitoring System
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Circle Safe, Inc.Industry (pharma, biotech, devices)
- Study start
- 17 Aug 2026 (estimated)
- Primary completion
- 31 Oct 2026 (estimated)
- Study completion
- 31 Oct 2026 (estimated)
- First posted
- 15 Sep 2026 (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 objective of this first-in-human study is to evaluate the safety and performance of the Circle Safe System in subjects undergoing pulmonary vein ablation for atrial fibrillation.
The main questions it aims to answer are:
- Can the Circle Safe System consistently stimulate the phrenic nerve and record a stable electrical response from the diaphragm?
- Can it reliably display changes in the diaphragm's response during ablation?
- What device-related or procedure-related medical problems occur during the study? There is no comparison group. All participants will undergo their planned pulmonary vein ablation while the Circle Safe System is used during treatment of the right pulmonary veins.
Participants will:
- Complete standard assessments before the procedure
- Have the Circle Safe catheter placed in the superior vena cava during the ablation procedure
- Have their phrenic nerve stimulated and their diaphragm response monitored using the Circle Safe System
- Be evaluated for device-related and procedure-related safety events through hospital discharge
Detailed description
During right pulmonary vein ablation, the Circle Safe catheter is advanced through the venous system and positioned in the superior vena cava. Its distal electrodes provide diagnostic stimulation of the right phrenic nerve, while its proximal electrodes record the resulting diaphragmatic compound motor action potential (CMAP).
The recorded signal is transmitted to the Circle Safe System Console, which displays the CMAP waveform and automatically compares its amplitude with a baseline measurement obtained before ablation. This allows changes in diaphragmatic activity to be monitored throughout treatment of the right pulmonary veins.
The Circle Safe System is a diagnostic monitoring aid. It does not deliver ablation energy, modify the ablation procedure, or replace standard phrenic nerve monitoring methods used by the physician. Device function, signal stability, procedural use, and any device deficiencies or adverse events are documented during the study.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Circle Safe System During Pulmonary Vein Ablation | Experimental | Device: Circle Safe System Use During Pulmonary Vein AblationParticipant will undergo pulmonary vein ablation while the Circle Safe System stimulates the right phrenic nerve |
Who may qualify
- Ages
- 19 to 84 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Male or females >18 and ≤ 85 years of age
- Subject willing to sign informed consent
- Subject is a candidate for pulmonary vein ablation for the treatment of atrial fibrillation ablation procedures therapy
Key exclusion criteria (7 listed)
- Subjects with pacemaker or defibrillator leads placed through the vena cava
- Subjects with implantable vena cava filter
- Subjects with a contraindication to contrast dye
- Pregnant subjects
- Subjects with inadequate venous access due to prior vein thrombosis or indwelling chronic ports or catheters
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 |
|---|---|---|
| Circle Safe System Use During Pulmonary Vein AblationThe Circle Safe System will be used during ablation of the right pulmonary veins to stimulate the right phrenic nerve and record and display the resulting diaphragmatic compound motor action potential. | Device | Circle Safe System During Pulmonary Vein Ablation |
Primary outcome
Freedom from device-related Major Adverse Events (MAEs) through hospital discharge. MAEs are defined as major thromboembolic events, vascular damage requiring surgical intervention, tamponade, perforation and ischemic stroke attributable to the device
Time frame: Through index discharge, an average of 24 hours
Proportion of subjects free from device-related Major Adverse Events (MAEs) through hospital discharge. MAEs are defined as major thromboembolic events, vascular damage requiring surgical intervention, tamponade, perforation, and ischemic stroke attributable to the Circle Safe System.
Primary Effectiveness Endpoint: Successful Recording and Display of Diaphragmatic Compound Motor Action Potential (CMAP) by the Circle Safe System
Time frame: Periprocedural
Ability of the Circle Safe System to record and display diaphragmatic compound motor action potential (CMAP) of patients undergoing pulmonary vein ablation procedures. Successful CMAP recordings are defined as: * The phrenic nerve can be captured consistently * A large, stable diaphragmatic CMAP baseline is recorded * Changes in amplitude can be tracked reliably throughout the ablation
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2026.
- Individual participant dataSharing planned: No
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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.
Stéphane COMBES, MD principal investigator
Clinique Pasteur - Toulouse - FRANCE
4 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Circle Safe System Use During Pulmonary Vein Ablation in people with Atrial Fibrillation, run by Circle Safe, Inc. at 4 sites in 2 countries.
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 3 inclusion and 7 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: opening soon, as of the sponsor's last update on 15 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in France, New Zealand. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jean-Maurice DUSSARTRE, MD (+33672926156, jm.dussartre@nxtcardio.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Freedom from device-related Major Adverse Events (MAEs) through hospital discharge. MAEs are defined as major thromboembolic events, vascular damage requiring surgical intervention, tamponade, perforation and ischemic stroke attributable to the device (time frame: Through index discharge, an average of 24 hours). The study lists 2 primary outcomes in all. 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 15 Sep 2026.