Quantification of Myocardial Blood Flow Using Dynamic PET/CTA Fused Imagery
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|ClinicalTrials.gov Identifier: NCT04221594|
Recruitment Status : Suspended (The study activities are suspended due to COVID)
First Posted : January 9, 2020
Last Update Posted : May 14, 2020
|Condition or disease||Intervention/treatment|
|Coronary Artery Disease||Procedure: Invasive Cardiac Catheterization (ICA) Procedure: Coronary Computed Tomographic Angiogram (CCTA) Procedure: Dynamic Cardiac Positron Emission Tomography (dPET)|
|Study Type :||Observational|
|Estimated Enrollment :||108 participants|
|Official Title:||Quantification of Myocardial Blood Flow Using Dynamic PET/CTA Fused Imagery to Determine the Physiological Significance of Specific Coronary Lesions.|
|Actual Study Start Date :||November 1, 2019|
|Estimated Primary Completion Date :||August 2022|
|Estimated Study Completion Date :||August 2022|
CAD detection/risk assessment
Patients with angina referred for the assessment of CAD will undergo imaging studies to develop tools to fuse coronary anatomic data obtained from CCTA with dPET data to non-invasively measure absolute MBF, MFR and RFR along vessels centerlines and across coronary lesions.
Procedure: Invasive Cardiac Catheterization (ICA)
Invasive functional measurements will be performed to assess the functional significance of specific lesions by means of FFR and CFR, and to test the presence of microvascular disease by means of IMR in all vessels for which the procedures are feasible. In summary, a 5- to 7-F guide catheter without side holes is used to engage the coronary artery and a pressure-temperature sensor-tipped guidewire introduced. The pressure sensor is positioned at the distal segment of a target vessel, and intracoronary nitroglycerine (100-200 mg) administered before each measurement. The best systolic and diastolic phase (located between 30-50%, and 60-75% of the cardiac cycle) will be selected for successive processing as it allows a relative motion free visualization of the main vessels and the myocardium.
Procedure: Coronary Computed Tomographic Angiogram (CCTA)
Fasting patients will undergo a test for coronary calcium by CT; calcium scoring analysis will be done post image data acquisition using the manufacturer's software. Nitroglycerine will be administered in all patients (sublingual administration prior to CCTA initiation). CT acquisitions will be prospectively ECG-gated (30-80% of the cardiac cycle). The acquisition begins with a scout scan to identify the borders of the heart to minimize the field of view and exposure to the patient. A bolus of 60 mL nonionic contrast agent is then injected followed by 60 mL of saline at a rate of 4 mL/s to enhance signal from coronary arteries and blood chambers. In case of irregular heart rate, beta-blockers can be provided to keep optimal heart rate ~65-70 bpm. Trans-axial images are reconstructed by means of a filtered back-projection algorithm.
Procedure: Dynamic Cardiac Positron Emission Tomography (dPET)
Patients will be asked to fast for 24 hours prior to the test. Before the resting perfusion phase, a single low-dose CT-based transmission scan is acquired for attenuation correction (AC) of all subsequent acquisitions. AC-CT images are automatically registered to the perfusion images, visually verified and manually corrected if necessary. Resting perfusion imaging started with the intravenous injection of a single bolus of 82Rb. Pharmacological stress imaging is obtained after adenosine infusion (140 μg/kg/min) through a peripheral vein, followed by a second dose of 82Rb. Image reconstruction is achieved by means of ordered subset expectation maximization (OSEM) iterative method. The hemodynamic responses to rest/stress tests are collected in terms of mean heart rate, mean blood systolic pressures and diastolic at rest and stress. Dynamic, gated and ungated trans-axial reconstructions are saved in DICOM format for further analysis and processing.
- Myocardial blood flow (MBF) measurement comparing non-invasive to the traditional approaches [ Time Frame: Up to 3 months ]Myocardial blood flow (MBF) measured in milliliters per minute per gram of tissue is providing unique pathophysiologic and diagnostic information on the function of the coronary macro- and microcirculation.
- Vessel-specific quantification of myocardial blood flow RFR [ Time Frame: Up to 3 months ]Ratio of absolute hyperemic MBFs (abnormal / normal) measured in mL/min/g.
- Absolute myocardial blood flow (MBF) measurement comparing non-invasive to the traditional approaches [ Time Frame: Up to 3 months ]Absolute myocardial blood flow (MBF) measured in ml/min/gm provides incremental diagnostic and prognostic information over relative perfusion alone.
- Myocardial flow reserve (MFR) measurement comparing non-invasive to the traditional approaches [ Time Frame: Up to 3 months ]Myocardial flow reserve (MFR) provide incremental diagnostic and prognostic information over relative perfusion alone.
- Fractional Flow Reserve (FFR) measurement comparing non-invasive to the traditional approaches [ Time Frame: Up to 3 months ]FFR calculates the maximum flow down a vessel in the presence of stenosis compared to maximum flow in the hypothetical absence of the stenosis.
- Stress myocardial blood flow (sMBF)/Regional myocardial blood flow (rMBF) ratio [ Time Frame: Up to 3 months ]Stress myocardial blood flow (sMBF)/Regional myocardial blood flow (rMBF) ratio will be calculated
- Distal/proximal pressure ratio [ Time Frame: Up to 3 months ]Distal/proximal pressure ratio will be calculated
- Discriminatory power of dPET/CTA. And FFR(CTA) [ Time Frame: Up to 3 months ]Predictive discriminatory power of each technique will be compared to ICA (FFR)
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04221594
|United States, Georgia|
|Atlanta, Georgia, United States, 30322|
|Emory University Hospital|
|Atlanta, Georgia, United States, 30322|
|Principal Investigator:||Marina Piccinelli, PhD||Emory University|