Aortic Sinus Dissection Causing STEMI

BACKGROUND: Localized aortic sinus dissection is a rare cause of acute coronary syndrome that is often undetected on initial imaging. CASE SUMMARY: A 72-year-old man with aortic root aneurysm presented with acute inferior ST-segment elevation myocardial infarction (STEMI). Initial computed tomography was negative for aortic dissection, however angiography revealed total occlusion of the right coronary artery (RCA) owing to coronary artery dissection. Percutaneous coronary intervention (PCI), challenging given an anomalous RCA ostium, successfully stented the occlusion. Subsequent high-resolution coronary computed tomography angiography identified right aortic sinus intimal tears extending into the RCA ostium; retrospective review of pre-PCI imaging confirmed dissection. The patient underwent Bentall surgery with RCA bypass. DISCUSSION: This case highlights a localized aortic sinus dissection mimicking primary coronary disease, emphasizing the importance of advanced imaging and the role of adaptive PCI as a bridge to definitive surgery. TAKE-HOME MESSAGES: Localized aortic sinus dissection can mimic acute STEMI and should be considered in patients with known aortic root disease, even when initial imaging appears unremarkable. High-resolution coronary computed tomography angiography is diagnostic; PCI for anomalous ostia may require advanced techniques. A heart team approach is vital for staged management.