Magnetocardiography as a Noninvasive Diagnostic Strategy for Identifying Coronary Allograft Vasculopathy

Study Overview
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Brief Summary
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Purpose: To show early feasibility of magnetocardiography (MCG) to identify coronary Cardiac positron emission tomography (PET) is the preferred non-invasive tests to assess for CAV and incorporation of quantitative myocardial blood flow (MBF) assessment improves diagnostic accuracy. Based on ISHLT criteria, the following have been proposed for diagnosis of CAV by PET:

Detailed Description
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Diagnosing CAV by PET with quantitative myocardial blood flow (MBF) 3 PET CAV 0: Normal perfusion with normal global stress (> 1.7 mL/min/g) PET CAV 1: Normal perfusion with abnormal global stress MBF (<1.7 mL/min/g and ejection fraction >45%) OR Single vessel perfusion defect with normal global stress MBF. PET CAV 2/3: Normal perfusion with abnormal global stress MBF (<1.7 mL/min/g) and ejection fraction < 45% OR Single vessel perfusion defect with abnormal global stress MBF (<1.7 mL/min/g) OR Multivessel perfusion defects With these diagnostic criteria, PET CAV 0 has been shown to have a high negative predictive value for moderate to severe CAV by invasive coronary angiography, and PET CAV 2/3 has been shown to have a high positive predictive value for moderate to severe CAV and is associated with adverse events. This study further examines the feasibility of MCG in identifying CAV in adult heart transplant recipients and compares those results to the current non-invasive standard using PET CAV scores. This will help determine whether MCG is a potential test for regular surveillance of CAV in transplant recipients.

Official Title
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Magnetocardiography as a Noninvasive Diagnostic Strategy for Identifying Coronary Allograft Vasculopathy

Conditions
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Coronary Allograft Vasculopathy (CAV)

Intervention / Treatment
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* Device: CardioFlux


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ≥ 18 years of age at the time of enrollment Willing to provide written informed consent Completed cardiac PET within the last 2 weeks No changes to medication or intervention since the PET was completed Exclusion Criteria: Patients unable to fit into device Patients unable to lie supine for 5 minutes Patients with implanted ferromagnetic objects above the costal margin of the rib cage (implanted pacemakers, cardioverter/defibrillators, infusion pumps, and/or neuro stimulators). NOTE: Sternotomy wires stents are acceptable Implanted pacemakers or cardioverter/defibrillators Implanted infusion pumps and/or neuro stimulators Severe claustrophobia

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| PET CAV 0<br>Normal perfusion with normal global stress (> 1.7 mL/min/g) | Device: CardioFlux<br>* CardioFlux MCG is a process that observes incremental changes in the heart's electrical activity by the magnetic fields generated by these currents. These magnetic fields have been used for decades via electrocardiogram to help diagnose and treat both acute and chronic cardiac pathology. The CardioFlux device reaches the potential of this phenomenon by sensing a complete magnetic field map. It is equipped with a magnetic shielding chamber and can attenuate magnetic field noise by a factor of nearly 1500 which maximizes signal to noise ratio. CardioFlux is an easy to operate, noninvasive modality that can detect the presence of ischemic cardiac tissue in symptomatic patients in a less than 5-minute scan. The device uses the proprietary software called Faraday which processes MCG scans, create diagnostic functional images, and run analytics.<br>|
| PET CAV 1<br>Normal perfusion with abnormal global stress MBF (<1.7 mL/min/g and ejection fraction >45%) OR Single vessel perfusion defect with normal global stress MBF. | Device: CardioFlux<br>* CardioFlux MCG is a process that observes incremental changes in the heart's electrical activity by the magnetic fields generated by these currents. These magnetic fields have been used for decades via electrocardiogram to help diagnose and treat both acute and chronic cardiac pathology. The CardioFlux device reaches the potential of this phenomenon by sensing a complete magnetic field map. It is equipped with a magnetic shielding chamber and can attenuate magnetic field noise by a factor of nearly 1500 which maximizes signal to noise ratio. CardioFlux is an easy to operate, noninvasive modality that can detect the presence of ischemic cardiac tissue in symptomatic patients in a less than 5-minute scan. The device uses the proprietary software called Faraday which processes MCG scans, create diagnostic functional images, and run analytics.<br>|
| PET CAV 2/3<br>Normal perfusion with abnormal global stress MBF (<1.7 mL/min/g) and ejection fraction < 45% OR Single vessel perfusion defect with abnormal global stress MBF (<1.7 mL/min/g) OR Multivessel perfusion defects v | Device: CardioFlux<br>* CardioFlux MCG is a process that observes incremental changes in the heart's electrical activity by the magnetic fields generated by these currents. These magnetic fields have been used for decades via electrocardiogram to help diagnose and treat both acute and chronic cardiac pathology. The CardioFlux device reaches the potential of this phenomenon by sensing a complete magnetic field map. It is equipped with a magnetic shielding chamber and can attenuate magnetic field noise by a factor of nearly 1500 which maximizes signal to noise ratio. CardioFlux is an easy to operate, noninvasive modality that can detect the presence of ischemic cardiac tissue in symptomatic patients in a less than 5-minute scan. The device uses the proprietary software called Faraday which processes MCG scans, create diagnostic functional images, and run analytics.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare the performance (diagnostic capabilities) of magnetocardiography in the diagnosis of coronary vasculopathy (CAV) as compared to PET as the currently accepted gold standard non-invasive tool. | Ability of MCG to identify CAV 0 in heart transplant patients as measured by sensitivity, specificity, positive predictive value, and negative predictive value. | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine whether MCG is able to differentiate between CAV 0, 1, and 2/3, and to correlate with absolute stress myocardial blood flow, global CFR (Coronary flow reserve), and LVEF (Left ventricular ejection fraction), as measured by cardiac PET | Differentiation between CAV 0, 1, and 2/3 Correlation of MCG with absolute stress myocardial blood flow Correlation of MCG with global CFR Correlation of MCG with LVEF | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Magnetocardiography