Utilizing Carbon Dioxide for Assessing Coronary Blood Flow in Subjects With Coronary Artery Disease (NIMO-CAD)

May 21, 2026 updated by: Rohan Dharmakumar, Indiana University

A Prospective Pilot Study to Evaluate the Safety, Tolerability and Technical Feasibility of Utilizing Carbon Dioxide (CO2) for Assessing Coronary Blood Flow in Subjects With Coronary Artery Disease

This is a prospective pilot study to evaluate the safety, tolerability and technical feasibility of utilizing carbon dioxide for assessing coronary blood flow in subjects with coronary artery disease.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

The purpose of this study is to noninvasively assess changes in the heart's blood flow through inducing changes in the amount of carbon dioxide in the participant's blood and having them breathe various combinations of carbon dioxide and oxygen.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Not Applicable

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

  • Name: Chandana Saha, PhD
  • Phone Number: 317 274 0975
  • Email: csaha@iu.edu

Study Locations

  • United States
    • Indiana
      • Indianapolis, Indiana, United States, 46202
        • IU Health Methodist Hospital
        • Contact:
          • Rohan Dharmakumar, PhD
          • Phone Number: 317-274-0992
          • Email: rdkumar@iu.edu
        • Sub-Investigator:
          • Keyur Vora, MD MS

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Adults > 18 years of age
  2. Clinically stable individuals with suspected or known coronary artery disease (CAD)
  3. The SPECT/PET study indicates at least a mild to moderate myocardial ischemia (>5-9%) or fractional-flow-reserve (FFR) of <0.75.

Exclusion Criteria:

  1. Prior myocardial infarction by clinical history (subjects with prior coronary revascularization without myocardial infarction will not be excluded)
  2. Hypotension (systolic blood pressure < 100 mmHg)
  3. Significant non-coronary cardiac disease (e.g., valvular abnormality, or cardiomyopathy, etc.)
  4. Inability to schedule the research study within 30 days of the SPECT/PET study and prior to any coronary revascularization procedure
  5. Inability to voluntarily increase their breathing rate if prompted to do so
  6. Persons with mechanically, magnetically, or electrically activated implants (such as cardiac pacemakers, neurostimulators, and infusion pumps), with ferromagnetic implants or foreign bodies (such as intracranial, aneurysm clips, shrapnel, and intraocular metal chips)
  7. Persons who are pregnant, nursing, or implanted with intrauterine devices (IUD's)
  8. Persons with a history of significant heart, lung, kidney, or liver disease
  9. Persons with asthma
  10. Persons who have abnormal cardiac rhythm and rate
  11. Persons unable to tolerate MRI secondary to an inability to lie supine for 60-90 minutes or severe claustrophobia
  12. Persons whose renal function test does not meet MRI contrast protocol requirements [estimated Glomerular filtration rate (eGFR) < 40 mL/min/1.73m2]
  13. Persons with a known history of allergy to gadolinium-based contrast
  14. Enrollment in another research study.
  15. Inability or unwillingness to provide informed consent

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

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Coronary Artery Disease (CAD) Subjects
Subjects with a of coronary artery disease will undergo computer-controlled gas challenges.
Device: RespirAct
RespirAct device-based computer-controlled gas delivery at different concentrations as per protocol

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Ratio of Maximum Signal Intensity (MSI) by BOLD MRI
Time Frame: 3 hours
Maximum Signal Intensity (MSI) quantification will be measured through myocardial perfusion by blood oxygen level dependent (BOLD) MRI. The ratio of MSI in hypercarbia vs normocarbia will be evaluated in the 17-segment LV model.
3 hours
Ratio of Maximum Signal Intensity (MSI) by FFP MRI
Time Frame: 3 hours
Maximum Signal Intensity (MSI) quantification will be measured through myocardial perfusion by first pass perfusion (FFP) MRI. The ratio of MSI in hypercarbia vs normocarbia will be evaluated in the 17-segment LV model.
3 hours

Collaborators and Investigators

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

Sponsor

Indiana University

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)

January 10, 2027

Primary Completion (Estimated)

November 15, 2027

Study Completion (Estimated)

December 15, 2027

Study Registration Dates

First Submitted

February 2, 2024

First Submitted That Met QC Criteria

February 2, 2024

First Posted (Actual)

February 12, 2024

Study Record Updates

Last Update Posted (Actual)

May 26, 2026

Last Update Submitted That Met QC Criteria

May 21, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 12319

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

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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