Trial Outcomes & Findings for PET MYOCARDIAL Blood Flow Comparison to Coronary CTA and CT-FFR (NCT NCT05349084)

Last Updated: 2024-09-26

Results Overview

CT presence of flow limiting stenosis (≤ 0.8) as determined by CT-FFR in comparison to invasive coronary artery (ICA) FFR. CT-FFR was determined in the following myocardial segments: left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA). The number of coronary artery stenoses as determined by CT (CT-FFR ≤ 0.8) was measured.

Recruitment status

COMPLETED

Study phase

Target enrollment

21 participants

Primary outcome timeframe

Day 1 - Day of Scan

Results posted on

2024-09-26

Participant Flow

Participant milestones

Participant milestones
Measure	PET-cCTA-cFFR Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
Overall Study STARTED	21
Overall Study COMPLETED	20
Overall Study NOT COMPLETED	1

Reasons for withdrawal

Reasons for withdrawal
Measure	PET-cCTA-cFFR Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
Overall Study Radiotracer production failed. Patient received an intervention so did not qualify to come back.	1

Baseline Characteristics

PET MYOCARDIAL Blood Flow Comparison to Coronary CTA and CT-FFR

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	PET-cCTA-cFFR n=21 Participants Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	10 Participants n=5 Participants
Age, Categorical >=65 years	11 Participants n=5 Participants
Age, Continuous	64.6 years STANDARD_DEVIATION 7.1 • n=5 Participants
Sex: Female, Male Female	14 Participants n=5 Participants
Sex: Female, Male Male	7 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	7 Participants n=5 Participants
Race (NIH/OMB) White	13 Participants n=5 Participants
Race (NIH/OMB) More than one race	1 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Region of Enrollment United States	21 participants n=5 Participants
Hypertension Yes	19 Participants n=5 Participants
Hypertension No	2 Participants n=5 Participants
Smoking Yes	12 Participants n=5 Participants
Smoking No	9 Participants n=5 Participants

PRIMARY outcome

Timeframe: Day 1 - Day of Scan

Population: One participant did not undergo imaging. Radiotracer production failed. Patient received an intervention so did not qualify to come back.

Outcome measures

Outcome measures
Measure	PET-cCTA-cFFR n=60 Coronary arteries Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
Number of Flow-limiting Coronary Artery Stenosis on CT	8 Coronary arteries

PRIMARY outcome

Timeframe: Day 1 - Day of Scan

Population: One participant did not undergo imaging. Radiotracer production failed. Patient received an intervention so did not qualify to return for imaging.

Association between N-13 Ammonia PET MBF (mL/g/min) during stress and presence or absence of coronary artery stenosis ≥ 50% diameter on CCTA as determined by measurement in each epicardial coronary artery. The MBF values during stress were categorized as normal or abnormal. Normal MBF is defined as \>1.8 mL/g/min. MBF and percent diameter stenosis were determined in the following myocardial segments: left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA).

Outcome measures

Outcome measures
Measure	PET-cCTA-cFFR n=60 Coronary arteries Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
Association Between Stress Myocardial Blood Flow (MBF) on PET and Coronary Artery Stenosis on CCTA Diameter Stenosis <50% · Normal MBF Stress	27 Coronary arteries
Association Between Stress Myocardial Blood Flow (MBF) on PET and Coronary Artery Stenosis on CCTA Diameter Stenosis ≥50% · Abnormal MBF Stress	9 Coronary arteries
Association Between Stress Myocardial Blood Flow (MBF) on PET and Coronary Artery Stenosis on CCTA Diameter Stenosis ≥50% · Normal MBF Stress	7 Coronary arteries
Association Between Stress Myocardial Blood Flow (MBF) on PET and Coronary Artery Stenosis on CCTA Diameter Stenosis <50% · Abnormal MBF Stress	17 Coronary arteries

SECONDARY outcome

Timeframe: Day 1 - Day of Scan

Population: One participant did not undergo imaging. Radiotracer production failed. Patient received an intervention so did not qualify to return for imaging.

Correlation of CT-FFR and N-13 Ammonia PET MBF (mL/g/min) during stress as determined by measurement in each epicardial coronary artery. Values were determined in the following myocardial segments: left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA).

Outcome measures

Outcome measures
Measure	PET-cCTA-cFFR n=60 Coronary arteries Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
Correlation of Myocardial Blood Flow (MBF) by PET to Fractional Flow Reserve (FFR) by CT.	0.284 Pearson correlation coefficient (r)

SECONDARY outcome

Timeframe: Day 1 - Day of Scan

Population: One participant did not undergo imaging. Radiotracer production failed. Patient received an intervention so did not qualify to come back.

CT-FFR was calculated using a computational flow/AI FFR program (Siemens). Normal CT-FFR was defined as \>0.80.

Outcome measures

Outcome measures
Measure	PET-cCTA-cFFR n=20 Participants Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
CT-Fractional Flow Reserve (CT-FFR) Global All Participant Analyzed	0.90 Ratio Standard Deviation 0.09
CT-Fractional Flow Reserve (CT-FFR) Global Participants with Normal CT-FFR	0.93 Ratio Standard Deviation 0.05
CT-Fractional Flow Reserve (CT-FFR) Global Participants with Abnormal CT-FFR	0.73 Ratio Standard Deviation 0.02

SECONDARY outcome

Timeframe: Day of invasive coronary catheterization - within 2 weeks of imaging

Population: iFR was done for 8 coronary arteries in 7 participants.

The instant wave Free Ratio (iFR) was measured during the patient's clinically scheduled invasive coronary catheterization. Normal iFR was defined as ≥ 0.90.

Outcome measures

Outcome measures
Measure	PET-cCTA-cFFR n=8 Coronary arteries Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
Instant Wave Free Ratio (iFR)	0.92 Ratio Standard Deviation 0.05

SECONDARY outcome

Timeframe: Day 1 - Day of Scan

Population: One participant did not undergo imaging. Radiotracer production failed. Patient received an intervention so did not qualify to come back.

Myocardial Blood Flow was measured by N-13 Ammonia positron emission tomography (PET) during stress following injection of regadenoson.

Outcome measures

Outcome measures
Measure	PET-cCTA-cFFR n=20 Participants Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
N-13 Ammonia PET Global Myocardial Blood Flow (MBF) Stress	1.88 mL/g/min Standard Deviation 0.45

SECONDARY outcome

Timeframe: Day 1 - Day of Scan

Population: One participant did not undergo imaging. Radiotracer production failed. Patient received an intervention so did not qualify to come back.

Myocardial Blood Flow (MBF) was measured by N-13 Ammonia positron emission tomography (PET) at rest.

Outcome measures

Outcome measures
Measure	PET-cCTA-cFFR n=20 Participants Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
N-13 Ammonia PET Global Myocardial Blood Flow (MBF) Rest	0.94 mL/g/min Standard Deviation 0.23

SECONDARY outcome

Timeframe: Day 1 - Day of Scan

Population: One participant did not undergo imaging. Radiotracer production failed. Patient received an intervention so did not qualify to come back.

Myocardial flow reserve (MFR) is a ratio between myocardial blood flow (MBF) during stress and at rest, as determined by positron emission tomography (PET). Normal MFR was defined as \> 2.0.

Outcome measures

Outcome measures
Measure	PET-cCTA-cFFR n=20 Participants Patients presenting with stable angina and a moderate pretest likelihood for coronary artery disease (CAD) who are already scheduled to undergo invasive coronary catheterization (ICA) for the clinical indication of angina will be recruited to undergo a Coronary CT Angiography (cCTA) examination with Fractional Flow Reserve (FFR) followed immediately by regadenoson stress-rest N-13 Ammonia Positron Emission Tomography (PET) on the same PET/CT scanner. Patients will undergo their clinically scheduled ICA with FFR within 2 weeks of the imaging procedures. Patients will receive two single intravenous injections of 10-12 mCi each of the PET radiotracer N-13 Ammonia, one during rest and one during stress. Stress imaging will occur 30-40 minutes prior to rest imaging. Patients will undergo PET/CT imaging immediately post N-13 Ammonia injection.
N-13 Ammonia PET Global Myocardial Flow Reserve (MFR) All Participants Analyzed	2.05 Ratio Standard Deviation 0.45
N-13 Ammonia PET Global Myocardial Flow Reserve (MFR) Participants with Normal MFR	2.31 Ratio Standard Deviation 0.31
N-13 Ammonia PET Global Myocardial Flow Reserve (MFR) Participants with Abnormal MFR	1.67 Ratio Standard Deviation 0.33

Adverse Events

PET-cCTA-cFFR

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Pamela K. Woodard

Washington University School of Medicine

Phone: 314-362-7100

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place