Cardiac Surgery for Bypass GraftingEPIMéCANCT07026851
Pilot Study to Establish a Repertoire of Megakaryocyte Markers, Quantifiable by Spectral Flow Cytometry, in Bone Marrow and Circulating in Patients Undergoing Cardiac Surgery for Bypass Grafting
An observational study of Cardiac Surgery for Bypass Grafting, run by University Hospital, Toulouse at 1 site in France.
Trial summary
Megakaryopoiesis, the mechanism of blood platelet production, is difficult to assess in clinical practice as it relies solely on microscopic description. Recent studies described the presence of emergency megakaryopoiesis bypassing the classical maturation stages under certain conditions. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cardiac Surgery for Bypass Grafting
- What is being tested?
- Blood and bone marrow sampling
- How many people
- 20 participants
- Where
- 1 siteFrance
- Study dates
- Jul 2025to Jul 2027
- Phase
- Observational
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Participants will be recruited from the Department of Cardiovascular Surgery at Rangueil Hospital, Toulouse University Hospital (CHU Toulouse), during scheduled hospitalizations for elective coronary artery bypass grafting. The study population consists of adult patients programmed for cardiac surgery, specifically coronary artery bypass grafting with sternotomy.
Who may be able to join
- Age over 18
- Indication for programmed cardiac surgery, specifically coronary artery bypass grafting with sternotomy
- Up to date social security coverage
- Patients able to understand the purpose and constraints of the research project
Who cannot join
- Refusal to participate in the study,
- Pregnant and/or breastfeeding women (clinical interview),
- Unscheduled cardiac surgery, Acquired hematologic disorders (acute leukemia, lymphomas, myelodysplastic syndromes, and myeloproliferative syndromes)
- Treatment with thrombopoietin receptor agonists
- Treatment with anti-inflammatory (included corticoids) or/and immunosuppressors
- Hematopoietic stem cell transplantation or organ transplantation
Show all 12Show fewer
- Active cancer with or without treatment (in remission, ongoing or treated within the last 6 months),
- Palliative care patients
- Any other type of cardiac surgery and previous sternotomy,
- History of external thoracic radiotherapy,
- Patient under legal protection (curatorship, guardianship or safeguard of justice)
- Patients with ongoing clinical trial requiring collection of additional blood or bone marrow samples
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site
Toulouse University Hospital
Toulouse
Agnès RIBES, 561322836 ext. +33, ribes.a@chu-toulouse.fr
Agnès RIBES
About this study
Megakaryopoiesis, the mechanism of blood platelet production, is difficult to assess in clinical practice as it relies solely on microscopic description. Recent studies described the presence of emergency megakaryopoiesis bypassing the classical maturation stages under certain conditions. Circulating megakaryocytes were identified in inflammatory and hemostatic conditions. The aim of this study is to characterize the phenotype of medullar and circulating megakaryocytes by flow cytometry during and after coronary artery bypass grafting.
Read the detailed description
Blood platelets, known for their role in primary hemostasis, are produced through the fragmentation of bone marrow megakaryocytes (MKs). In recent years, the characterization of new platelet functions, particularly in innate immunity and inflammatory processes, has reshaped the paradigm of sequential bone marrow megakaryopoiesis. Indeed, numerous studies provide evidence of a more direct, so-called "emergency" platelet production, which bypasses the successive stages of megakaryocyte differentiation. Furthermore, megakaryopoiesis may not be exclusively marrow-based; splenic and pulmonary sites are also described, along with circulating megakaryocytes in peripheral blood. These circulating megakaryocytes are gaining interest due to their easier accessibility and specific characteristics, notably pro-inflammatory properties.
However, to date, clinical practice analysis of megakaryocytes remains limited to simple microscopic description. Given recent observations as outlined above, a more precise and in-depth description of megakaryocytes, whether marrow-based or blood-based, appears essential for understanding pathophysiological mechanisms. Flow cytometry (FC) coupled with spectral technology overcomes the traditional limitations of FC. This technique has allowed our team to describe different stages of marrow megakaryocyte maturation using a murine model of platelet pathology.
In this context, cardiac surgery with extracorporeal circulation for coronary artery bypass grafting could serve as a model for inflammatory and hemostatic challenges. Post-procedural thrombocytopenia is common and is partly correlated with the duration of extracorporeal circulation (ECC), which could be associated with thrombo-inflammation responsible for acute kidney injury or stroke. Due to both the physiological bone marrow challenge posed by this procedure and the ease of bone marrow collection inherent to this technique, this situation seems well-suited for conducting this feasibility study.
Currently, no study has described the impact of megakaryocyte phenotype on platelet changes induced by cardiac surgery, whether these changes are purely quantitative or associated with a deleterious pro-inflammatory post-procedural context.
Based on these elements, combined with the expertise we have gained from studying the megakaryocyte/platelet axis in small animals using spectral flow cytometry, we propose:
- To validate the established antibody panel that allows the identification and quantification of the different maturation stages of bone marrow megakaryocytes,
- To apply this panel to circulating megakaryocytes before and after the surgical procedure,
- To correlate the observations with the potential inflammatory signature for each patient.
The rationale for this pilot study is to consider circulating megakaryocytes as a new, accessible, and highly specific indicator of thrombo-inflammatory processes.
- Conditions
- Cardiac Surgery for Bypass Grafting
- Being tested
- Blood and bone marrow sampling
- Keywords
- Megakaryocytes, flow cytometry, cardiac surgery
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Blood and bone marrow samplingBiological
This intervention involves the collection of peripheral blood before and 3 days after coronary artery bypass grafting (CABG), as well as a one-time collection of bone marrow sample during sternotomy.
Samples are analyzed using spectral flow cytometry to characterize the phenotype and maturation stages of circulating and medullary megakaryocytes using a panel of specific surface antibodies.
| Study group | Role | What they receive |
|---|---|---|
| Coronary Artery Bypass Grafting Patients Undergoing Bone Marrow and Blood Megakaryocyte Phenotyping | Not described Receives: Biological: Blood and bone marrow sampling |
What is being measured
The primary outcome is the main question the study is designed to answer.
Phenotype of bone marrow and circulating megakaryocytes
Circulating and bone marrow megakaryocytes will be analyzed using spectral flow cytometry on samples collected during coronary artery bypass surgery. Cells will be labeled with a panel of specific surface antibodies . Megakaryocytes will be classified by maturation stage (multipotent progenitor [MPP], common myeloid progenitor [CMP], megakaryocyte-erythrocyte progenitor [MEP], pro-megakaryocyte [proMK], immature megakaryocyte [imMK], mature megakaryocyte [MK]) and specialization status (specialized MKs).
Measured: Day of surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Jun 2025
- Study startJul 2025 (estimated)
- Primary completionJul 2027 (estimated)
- Study completionJul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cardiac Surgery for Bypass GraftingStudies of the same condition, open and under way.
- More trials run by University Hospital, ToulouseThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Toulouse
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Agnès Ribes, Principal investigator, Toulouse, Rangueil Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07026851
- Sponsor's protocol ID
- RC31/25/0106
- Other IDs
- ID-RCB : 2025-A00744-45
- Acronym
- EPIMéCA
- Status last verified
- Jun 2025
- First submitted
- 10 Jun 2025
- Last updated
- 18 Jun 2025
- 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 18 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pilot Study to Establish a Repertoire of Megakaryocyte Markers, Quantifiable by Spectral Flow Cytometry, in Bone Marrow and Circulating in Patients Undergoing Cardiac Surgery for Bypass Grafting
- ClinicalTrials.gov ID
- NCT07026851
- Acronym / sponsor ID
- EPIMéCA / RC31/25/0106
- Conditions
- Cardiac Surgery for Bypass Grafting
- Keywords
- Megakaryocytes, flow cytometry, cardiac surgery
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University Hospital, ToulouseUniversity, hospital or other
- Study start
- Jul 2025 (estimated)
- Primary completion
- Jul 2027 (estimated)
- Study completion
- Jul 2027 (estimated)
- First posted
- 18 Jun 2025 (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.
Megakaryopoiesis, the mechanism of blood platelet production, is difficult to assess in clinical practice as it relies solely on microscopic description. Recent studies described the presence of emergency megakaryopoiesis bypassing the classical maturation stages under certain conditions. Circulating megakaryocytes were identified in inflammatory and hemostatic conditions. The aim of this study is to characterize the phenotype of medullar and circulating megakaryocytes by flow cytometry during and after coronary artery bypass grafting.
Detailed description
Blood platelets, known for their role in primary hemostasis, are produced through the fragmentation of bone marrow megakaryocytes (MKs). In recent years, the characterization of new platelet functions, particularly in innate immunity and inflammatory processes, has reshaped the paradigm of sequential bone marrow megakaryopoiesis. Indeed, numerous studies provide evidence of a more direct, so-called "emergency" platelet production, which bypasses the successive stages of megakaryocyte differentiation. Furthermore, megakaryopoiesis may not be exclusively marrow-based; splenic and pulmonary sites are also described, along with circulating megakaryocytes in peripheral blood. These circulating megakaryocytes are gaining interest due to their easier accessibility and specific characteristics, notably pro-inflammatory properties.
However, to date, clinical practice analysis of megakaryocytes remains limited to simple microscopic description. Given recent observations as outlined above, a more precise and in-depth description of megakaryocytes, whether marrow-based or blood-based, appears essential for understanding pathophysiological mechanisms. Flow cytometry (FC) coupled with spectral technology overcomes the traditional limitations of FC. This technique has allowed our team to describe different stages of marrow megakaryocyte maturation using a murine model of platelet pathology.
In this context, cardiac surgery with extracorporeal circulation for coronary artery bypass grafting could serve as a model for inflammatory and hemostatic challenges. Post-procedural thrombocytopenia is common and is partly correlated with the duration of extracorporeal circulation (ECC), which could be associated with thrombo-inflammation responsible for acute kidney injury or stroke. Due to both the physiological bone marrow challenge posed by this procedure and the ease of bone marrow collection inherent to this technique, this situation seems well-suited for conducting this feasibility study.
Currently, no study has described the impact of megakaryocyte phenotype on platelet changes induced by cardiac surgery, whether these changes are purely quantitative or associated with a deleterious pro-inflammatory post-procedural context.
Based on these elements, combined with the expertise we have gained from studying the megakaryocyte/platelet axis in small animals using spectral flow cytometry, we propose:
- To validate the established antibody panel that allows the identification and quantification of the different maturation stages of bone marrow megakaryocytes,
- To apply this panel to circulating megakaryocytes before and after the surgical procedure,
- To correlate the observations with the potential inflammatory signature for each patient.
The rationale for this pilot study is to consider circulating megakaryocytes as a new, accessible, and highly specific indicator of thrombo-inflammatory processes.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Coronary Artery Bypass Grafting Patients Undergoing Bone Marrow and Blood Megakaryocyte Phenotyping | – | Biological: Blood and bone marrow sampling |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Participants will be recruited from the Department of Cardiovascular Surgery at Rangueil Hospital, Toulouse University Hospital (CHU Toulouse), during scheduled hospitalizations for elective coronary artery bypass grafting. The study population consists of adult patients programmed for cardiac surgery, specifically coronary artery bypass grafting with sternotomy.
Key inclusion criteria (4 listed)
- Age over 18
- Indication for programmed cardiac surgery, specifically coronary artery bypass grafting with sternotomy
- Up to date social security coverage
- Patients able to understand the purpose and constraints of the research project
Key exclusion criteria (12 listed)
- Refusal to participate in the study,
- Pregnant and/or breastfeeding women (clinical interview),
- Unscheduled cardiac surgery, Acquired hematologic disorders (acute leukemia, lymphomas, myelodysplastic syndromes, and myeloproliferative syndromes)
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 |
|---|---|---|
| Blood and bone marrow samplingThis intervention involves the collection of peripheral blood before and 3 days after coronary artery bypass grafting (CABG), as well as a one-time collection of bone marrow sample during sternotomy. Samples are analyzed using spectral flow cytometry to characterize the phenotype and maturation stages of circulating and medullary megakaryocytes using a panel of specific surface antibodies. | Biological | Coronary Artery Bypass Grafting Patients Undergoing Bone Marrow and Blood Megakaryocyte Phenotyping |
Primary outcome
Phenotype of bone marrow and circulating megakaryocytes
Time frame: Day of surgery
Circulating and bone marrow megakaryocytes will be analyzed using spectral flow cytometry on samples collected during coronary artery bypass surgery. Cells will be labeled with a panel of specific surface antibodies . Megakaryocytes will be classified by maturation stage (multipotent progenitor [MPP], common myeloid progenitor [CMP], megakaryocyte-erythrocyte progenitor [MEP], pro-megakaryocyte [proMK], immature megakaryocyte [imMK], mature megakaryocyte [MK]) and specialization status (specialized MKs).
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 18 Jun 2025.
- 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.
Agnès Ribes principal investigator
Toulouse, Rangueil Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Cardiac Surgery for Bypass Grafting, run by University Hospital, Toulouse at 1 site in France.
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 4 inclusion and 12 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 18 Jun 2025. 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 France. 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 Agnès Ribes (+33(0)5.61.32.28.36 ext. +33, ribes.a@chu-toulouse.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Phenotype of bone marrow and circulating megakaryocytes (time frame: Day of surgery). 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 18 Jun 2025.