A case report unmasking two functional cases of non-obstructive coronary artery disease in the young: two mechanisms and one diagnostic key

Background: Ischemia with Non-obstructive Coronary Arteries (INOCA) historically considered benign, is now recognized as a cause of recurrent angina, functional limitation and adverse cardiovascular outcomes. In some patients, it may progress to myocardial infarction with non-obstructive coronary arteries (MINOCA). Recognition in younger individuals remains limited, contributing to delay in diagnosis and treatment. Case Presentation: Patient 1: A 16-year-old previously healthy male presented with paroxysmal palpitations and chest discomfort at rest. Nine months later, recurrent symptoms were accompanied by transient ST-segment depression on serial electrocardiography and elevated high-sensitivity troponin I (614 ng/L). Coronary angiography showed unobstructed epicardial vessels. Cardiac magnetic resonance (CMR) revealed focal subendocardial late gadolinium enhancement in the basal inferolateral wall consistent with vasospasm-induced myocardial infarction.Patient 2: A 34-year-old man reported four months of exertional chest discomfort and dyspnea on exertion with normal serial electrocardiography and troponin. Coronary angiography revealed normal epicardial vessels. Adenosine stress CMR identified diffuse subendocardial perfusion defects with quantitatively reduced myocardial blood flow (1.54 ml/min/g) consistent with global microvascular dysfunction. Conclusion: These cases underscore that INOCA can affect young individuals without traditional risk factors, and that CMR offers definitive diagnostic and prognostic value when invasive angiography is non-contributory.