Magnetocardiography as a Noninvasive Diagnostic Strategy for Suspected Myocardial Ischemia With No Obstructive Coronary Artery Disease

Magnetocardiography (MCG) is a noninvasive imaging modality that has been extensively studied over the past several decades as a diagnostic imaging solution for various forms of cardiovascular disease. MCG measures the magnetic field that arises from the electrical activity of the heart's pacemaker activity, the very same activity which yields surface electric field potentials as measured by the electrocardiogram. Unlike electrocardiographic signals, however, MCG signals are undistorted by conductive tissue noise, and are highly sensitive to ischemic injury and vortex currents missed by the same electrocardiographic measurements. Accordingly, numerous clinical trials suggest the usefulness of MCG for the evaluation of ischemia in patients with suspected acute coronary syndrome.

There is a growing body of evidence demonstrating the usefulness of MCG in the detection of myocardial ischemia, both in patients with symptoms of ACS, and in patients with stable angina. Since MCG is a functional assessor of depolarization and repolarization heterogeneity, it is hypothesized that MCG may be a useful frontline diagnostic modality to identify CMD in patients who would otherwise have normal coronary CT angiograms and/or stress tests. The proposed study intends to study the diagnostic accuracy of MCG in patients with suspected INOCA.

This demonstrates a significant unmet clinical need in the assessment of patients, and especially women, with INOCA. The current standard of care for these patients is resource/time intensive and associated with a significant rate of non-diagnostic clinical data requiring expensive and invasive evaluation for safe patient management. Magnetocardiography offers the potential for rapid, safe, noninvasive, non-radiologic assessment of the INOCA population, and may lead to earlier treatment strategies for CMD patients.

From the participating clinical sites, patients age ≥18 years who presented with chest pain or exertional dyspnea concerning for myocardial ischemia with no obstructive epicardial CAD on invasive or computed tomographic coronary angiography will be screened and subsequently enrolled when meeting criteria. This is a prospective observational study used for clinical data collection for the clinical validation testing of the CardioFlux MCG system. There will be no intervention introduced by the study device. The interpretation of the CardioFlux MCG data made by the study reader(s) will not be known to the patient's treating physician. Similarly, the patient's coronary physiology data, diagnosis, or interventions made by the patient's treating physician in following the standard of care will not be known to any of the scan readers. Except for the introduction of the MCG scan, there will be no other alteration to the patient standard of care.