Utilizing Carbon Dioxide for Assessing Coronary Blood Flow in Subjects With Coronary Artery Disease

Not Applicable

Not yet recruiting

• Conditions: Coronary Artery Disease
• Interventions: Device: RespirAct

• Registration Number: NCT06253884
• Lead Sponsor: Indiana University

Brief Summary

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.

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 Timeline

• Study First Submitted: 2024-02-02
• Study First Submitted QC: 2024-02-02
• Study First Posted: 2024-02-12
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-03
• Last Update Posted: 2025-03-05
• Study Start: 2025-07-01
• Primary Completion: 2026-06-15
• Study Completion: 2026-07-15

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 30

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Coronary Artery Disease (CAD) Subjects	RespirAct	Subjects with a of coronary artery disease will undergo computer-controlled gas challenges.

Primary Outcome Measures

Name	Time	Method
Ratio of Maximum Signal Intensity (MSI) by BOLD MRI	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.
Ratio of Maximum Signal Intensity (MSI) by FFP MRI	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.

Trial Locations

Locations (1)

IU Health Methodist Hospital; 🇺🇸 Indianapolis, Indiana, United States