Intraoperative Ultrasound Assessment of Coronary Artery and Bypass Graft Blood Flow During CABG

August 6, 2026 updated by: The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School

Quantitative Assessment of Native Coronary Artery and Bypass Graft Blood Flow Using Intraoperative Ultrasound in Patients Undergoing Coronary Artery Bypass Grafting: A Single-Centre Prospective Feasibility and Safety Study

This single-centre, prospective observational feasibility and safety study will enrol 190 consecutive adults undergoing elective isolated coronary artery bypass grafting (CABG) at Nanjing Drum Tower Hospital. The study aims to evaluate the feasibility and safety of intraoperative ultrasound for the quantitative assessment of native coronary artery and bypass graft blood flow.

Transit-time flow measurement will be performed as part of routine intraoperative graft assessment. Additional ultrasound measurements will be obtained from major native coronary arteries before and after revascularisation and from bypass grafts after restoration of blood flow. The ultrasound findings will be collected for research purposes and will not influence graft revision or other intraoperative clinical decisions.

The co-primary outcomes are the participant-level technical success rate of the protocol-defined intraoperative ultrasound assessment and the incidence of adverse events related to the ultrasound device or measurement procedure. Secondary outcomes include agreement between ultrasound and transit-time flow measurements, changes in native coronary artery blood flow after revascularisation, measurement repeatability, and exploratory associations between intraoperative flow parameters and postoperative cardiac function and myocardial injury biomarkers. Participants will be followed for 30 ± 7 days after surgery.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

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Intervention / Treatment

Intervention / Treatment

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Detailed Description

Intraoperative assessment of bypass graft function is important for ensuring adequate myocardial revascularisation during coronary artery bypass grafting. Transit-time flow measurement is widely used for graft assessment but primarily evaluates blood flow within bypass grafts and provides limited information on changes in native coronary artery blood flow before and after revascularisation.

This study will evaluate a portable ultrasound platform with access to programmable raw radiofrequency data. The study-specific procedure consists of additional intraoperative ultrasound measurements obtained from the exposed epicardial surface without additional incision, vascular puncture or tissue penetration. Major native coronary arteries will be assessed before and after revascularisation, and individual bypass grafts will be assessed after completion of the graft anastomoses and restoration of blood flow. Transit-time flow measurements will be recorded according to routine clinical practice for subsequent agreement analyses.

The research ultrasound findings will not be used to guide graft revision, repeat anastomosis or other intraoperative clinical decisions. The study is designed to evaluate technical feasibility, safety, agreement with transit-time flow measurement, measurement repeatability and changes in native coronary artery blood flow. Associations between intraoperative flow parameters and postoperative cardiac function and myocardial injury biomarkers will be exploratory.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
190

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • China
    • Jiangsu
      • Nanjing, Jiangsu, China, 210008
        • Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of adults undergoing elective isolated coronary artery bypass grafting in the Department of Cardiac Surgery at Nanjing Drum Tower Hospital. Consecutive patients meeting the eligibility criteria will be screened and enrolled after providing written informed consent.

Description

Inclusion Criteria:

  • Aged 18 years or older.
  • Confirmed coronary artery disease and scheduled to undergo elective isolated coronary artery bypass grafting at Nanjing Drum Tower Hospital.
  • Able and willing to provide written informed consent before any study-specific procedures are performed.

Exclusion Criteria:

  • Urgent, emergency, or salvage coronary artery bypass grafting.
  • Prolonged preoperative fasting, as defined in the study protocol, or inability to maintain adequate oral intake without enteral or parenteral nutritional support.
  • History of malignancy.
  • Body weight below 50 kg.
  • Preoperative hemodynamic instability requiring ongoing resuscitation or mechanical circulatory support, including intra-aortic balloon pump, extracorporeal membrane oxygenation, or left ventricular assist device support.
  • Endotracheal intubation and invasive mechanical ventilation before surgery.
  • Impaired consciousness, clinically significant central nervous system dysfunction, or evidence of cerebral malperfusion after hospital admission.
  • End-stage renal disease requiring maintenance dialysis before hospital admission.
  • Severe pulmonary disease considered to preclude tolerance of elective coronary artery bypass grafting or to confer an unacceptably high perioperative risk.
  • Severe peripheral vascular disease or clinical evidence of limb malperfusion before surgery.
  • History of gastrointestinal ulceration or chronic inflammatory gastrointestinal disease.
  • Chronic inflammatory or autoimmune disease, or long-term treatment with systemic corticosteroids or non-steroidal anti-inflammatory drugs.
  • Active infection or sepsis at screening.
  • Severe uncontrolled arrhythmia requiring urgent treatment or expected to cause marked intraoperative hemodynamic instability.
  • Previous cardiac surgery requiring repeat median sternotomy.
  • Planned concomitant major cardiac or aortic surgery, including valve surgery, congenital heart defect repair, or aortic surgery.
  • Inability to understand the study information or unwillingness or inability to provide written informed consent.
  • Inability or unwillingness to complete follow-up at 30 ± 7 days after surgery.
  • Pregnancy or breastfeeding.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Intraoperative Ultrasound CABG Cohort
This cohort will prospectively include adults undergoing elective isolated coronary artery bypass grafting. Ultrasound-derived blood flow parameters of native coronary arteries and bypass grafts will be collected at prespecified intraoperative time points. Transit-time flow measurements, perioperative data, postoperative cardiac function and myocardial injury biomarkers will also be collected. No parallel control cohort will be established, and the research ultrasound findings will not influence intraoperative clinical decision-making.
Diagnostic test: Intraoperative Ultrasound Blood Flow Measurement
Intraoperative ultrasound measurements of major native coronary arteries will be obtained before and after revascularisation, followed by measurements of individual bypass grafts after restoration of blood flow. Recorded variables will include blood flow velocity, volumetric blood flow and other protocol-defined quantitative parameters. The findings will be collected for research purposes and will not guide graft revision or other intraoperative clinical decisions.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Participant-Level Technical Success Rate of the Protocol-Defined Intraoperative Ultrasound Assessment
Time Frame: During the coronary artery bypass grafting procedure
The proportion of enrolled participants with analysable quantitative flow parameters obtained from ultrasound measurements of at least two major native coronary arteries both before and after revascularisation and from all protocol-specified independent bypass grafts. Failure to initiate or complete a protocol-defined measurement, visualise a required target vessel, obtain a stable flow signal, or generate analysable data will be classified as technical failure and retained in the denominator.
During the coronary artery bypass grafting procedure
Incidence of Adverse Events Related to the Intraoperative Ultrasound Device or Measurement Procedure
Time Frame: From the first intraoperative ultrasound measurement to 30 ± 7 days after surgery
The proportion of participants with any adverse event judged by the investigator as possibly, probably, or definitely related to the intraoperative ultrasound device or measurement procedure. Prespecified events of special interest include a new or worsened sustained arrhythmia requiring treatment; clinically significant haemodynamic instability; bleeding or tissue injury attributable to probe contact or manipulation; native coronary artery, graft, or anastomotic injury; interruption or clinically meaningful prolongation of surgery attributable to ultrasound measurement; device malfunction posing a patient safety risk; and other related events as judged by the investigator.
From the first intraoperative ultrasound measurement to 30 ± 7 days after surgery

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Agreement Between Intraoperative Ultrasound and Transit-Time Flow Measurements
Time Frame: During CABG, after completion of graft anastomoses and restoration of blood flow
Agreement between comparable bypass graft blood flow parameters obtained using intraoperative ultrasound and transit-time flow measurement will be evaluated in grafts with analysable paired measurements using intraclass correlation coefficients and Bland-Altman analysis.
During CABG, after completion of graft anastomoses and restoration of blood flow
Mean Within-Vessel Change in Ultrasound-Derived Volumetric Blood Flow of Native Coronary Arteries Before and After Revascularisation
Time Frame: During CABG: immediately before revascularisation and after completion of graft anastomoses following haemodynamic stabilisation
Volumetric blood flow will be measured in the same analysable segments of the left anterior descending, left circumflex, and right coronary arteries immediately before revascularisation and after completion of graft anastomoses following haemodynamic stabilisation. For each analysable native coronary artery, the within-vessel change will be calculated as post-revascularisation volumetric blood flow minus pre-revascularisation volumetric blood flow. The native coronary artery will be the unit of analysis, and the mean of all analysable vessel-level change values will be reported in mL/min. Positive values indicate increased blood flow after revascularisation.
During CABG: immediately before revascularisation and after completion of graft anastomoses following haemodynamic stabilisation
Repeatability of Intraoperative Ultrasound Blood Flow Measurements
Time Frame: During the coronary artery bypass grafting procedure
Repeatability of intraoperative ultrasound-derived quantitative blood flow parameters will be evaluated using repeated measurements obtained at the same vascular measurement site. Intraclass correlation coefficients, coefficients of variation, repeatability coefficients, and Bland-Altman limits of agreement will be calculated.
During the coronary artery bypass grafting procedure
Association of Intraoperative Blood Flow Parameters With Postoperative Cardiac Function and Myocardial Injury Biomarkers
Time Frame: From the preoperative baseline assessment to 30 ± 7 days after surgery
Associations between intraoperative ultrasound-derived native coronary artery and bypass graft blood flow parameters and postoperative measures of cardiac function, cardiac structure, and myocardial injury will be explored. Planned measures include left ventricular ejection fraction, left ventricular end-diastolic diameter, B-type natriuretic peptide or N-terminal pro-B-type natriuretic peptide, cardiac troponin T or cardiac troponin I, and other protocol-defined measures.
From the preoperative baseline assessment to 30 ± 7 days after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Qiang Wang, MD, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2027

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 7, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 7, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 14, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 11, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 6, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • NJGH-CABG-US2026
  • 12274220 (Other Grant/Funding Number: National Natural Science Foundation of China)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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