Abstract
BACKGROUND: Moyamoya disease causes vasculopathic changes not only in intracranial arteries but also in extracranial vessels, including coronary arteries. CASE SUMMARY: A 25-year-old man collapsed from ventricular fibrillation and was resuscitated. Coronary angiography revealed left anterior descending artery occlusion, and optical coherence tomography demonstrated diffuse intimal thickening and thrombus formation without plaque rupture. Percutaneous intervention restored coronary flow. Subsequent evaluations revealed vasospastic angina and moyamoya disease. DISCUSSION: This case highlights the unique pathophysiological mechanism of acute myocardial infarction in moyamoya disease, where fibrous intimal thickening predisposes to coronary spasm and thrombus formation, distinct from traditional atherosclerotic processes. Optical coherence tomography played a key role in identifying plaque morphology, guiding diagnosis, and management. TAKE-HOME MESSAGE: Recognition of systemic vascular disorders, such as moyamoya disease, is essential in young patients with acute coronary syndrome to improve outcomes and prevent recurrence.