Magnetocardiography in the diagnosis of suspected ANOCA: a case series

Patients with angina pectoris with non-obstructive coronary artery disease (ANOCA) often present to cardiology outpatient clinic or emergency departments with manifestations mimicking acute coronary syndrome (ACS). As a working diagnosis defined by angina pectoris in the absence of obstructive coronary arteries, ANOCA requires a stepwise diagnostic process-one that incorporates coronary functional assessments and provocative tests. Magnetocardiography (MCG) is a diagnostic modality with the potential to distinguish mild myocardial ischemic in patients with suspected ANOCA from nonischemic cardiac presentations, thereby shortening the diagnostic timeline and optimizing the clinical workflow. Three patients with angina pectoris and non-obstructive coronary arteries on CCTA were referred for MCG evaluation. We evaluated ischemic features on MCG waveforms. Notably, even in cases where ischemia could not be identified via electrocardiography (ECG), the ischemic features on MCG waveforms remained highly prominent. This study describes the clinical and MCG features of patients with suspected ANOCA, explores MCG's utility for diagnosing coronary microvascular dysfunction (CMD), and informs future research. The application potential of MCG in cardiology-specifically for the evaluation of acute chest pain-has recently garnered significant attention. To our knowledge, prior investigations in the context of ANOCA or CMD have not focused on the systematic characterization of specific MCG waveform patterns. Our documentation of positive MCG findings in these patients presenting with suspected ACS but having non-obstructive arteries supports MCG's potential in detecting subtle ischemia and optimizing clinical workflow.