Recurrent ST-Segment Elevation Myocardial Infarction (STEMI) in Localized Coronary Artery Ectasia Without Significant Obstructive Coronary Disease: A Therapeutic Dilemma

Coronary artery ectasia (CAE) is an uncommon angiographic abnormality characterized by the abnormal dilatation of the coronary arteries. Although frequently associated with atherosclerosis, CAE may promote sluggish coronary blood flow, thrombus formation, and distal embolization, resulting in acute coronary syndrome (ACS) even in the absence of significant obstructive coronary artery disease. The optimal management of ACS associated with CAE remains uncertain because current evidence is limited and no standardized therapeutic strategy has been established. We report the case of a 52-year-old man with multiple cardiovascular risk factors and a previous inferior ST-segment elevation myocardial infarction (STEMI) who presented with recurrent inferior STEMI four years later. Emergency coronary angiography revealed marked localized ectasia of the proximal-to-mid right coronary artery measuring approximately 10 mm in diameter, containing a heterogeneous non-obstructive lesion (<30%) with preserved TIMI 3 flow and no angiographic evidence of acute vessel occlusion. Given the absence of a culprit lesion requiring revascularization, conservative medical management was adopted. The patient was treated with dual antiplatelet therapy, high-intensity statin therapy, beta-blocker, angiotensin-converting enzyme inhibitor, and therapeutic-dose low-molecular-weight heparin, with long-term oral anticoagulation planned because of recurrent thrombotic events. This case highlights an uncommon mechanism of recurrent STEMI related to localized CAE without significant obstructive coronary disease. It emphasizes the diagnostic and therapeutic challenges posed by this condition and supports an individualized management strategy based on angiographic findings and thrombotic risk until stronger evidence becomes available.