ST-segment elevation myocardial infarction due to septic coronary embolism: a case report

Coronary artery embolism is an infrequent cause of type 2 myocardial infarction which can be due to arterial thromboembolism or septic embolism. While systemic embolization is one of the most acknowledged and threatened complications of infective endocarditis, coronary localization of the emboli causing acute myocardial infarction is exceedingly rare occurring in <1% of cases.

A 52-year-old man with a history of Bentall procedure and redo aortic valve replacement due to prosthetic degeneration (11 years prior to the current presentation) presented to the emergency department with high-grade fever and myalgias. Shortly after his arrival, he experienced typical chest pain and an electrocardiogram demonstrated signs of inferior ST-elevation myocardial infarction: coronary angiography showed a lesion of presumed embolic origin at the level of the mid-distal circumflex coronary artery which was treated with embolectomy. Transthoracic and transoesophageal echocardiography highlighted the presence of a periaortic abscess. The final diagnosis of infective endocarditis as the cause of septic coronary artery embolization was confirmed with a Positron Emission Tomography-Computed Tomography (PET-CT) exam and by the growth of Staphylococcus lugdunensis on repeated blood cultures. The patient underwent successful redo Bentall surgery the good outcome was confirmed at 1-month follow-up.

Type 2 myocardial infarction caused by coronary embolism is a rare presentation of infective endocarditis and requires a high level of suspicion for its diagnosis. Prosthetic heart valves are a predisposing factor for infective endocarditis: aortic root abscess requires surgery as it rarely regresses with antibiotic therapy.