Septic coronary embolism presenting as anterior STEMI: a stentless PCI strategy guided by clinical inconsistency and pathological confirmation—case report

Abstract Background Septic coronary embolism is an uncommon cause of acute myocardial infarction and may mimic atherosclerotic occlusion. Early distinction between these mechanisms is essential because routine stent implantation may be hazardous in bacteremic conditions. Case summary A 48-year-old man presented with an anterior ST-segment elevation myocardial infarction with high fever. Coronary angiography revealed abrupt mid–left anterior descending artery occlusion with a smooth vessel contour (Figure 1). Intravascular ultrasound showed a large intraluminal thrombus without underlying plaque (Figure 2). Because these findings were inconsistent with plaque rupture, stent implantation was intentionally avoided. Pathological analysis of the aspirated thrombus demonstrated bacterial colonies (Figure 3), confirming septic coronary embolism due to methicillin-sensitive Staphylococcus aureus infective endocarditis. The patient subsequently developed acute severe aortic regurgitation secondary to left coronary cusp perforation on transesophageal echocardiography (Figures 4 and 5) and underwent urgent aortic valve replacement.