When MRSA Travels

We report a case of methicillin-resistant Staphylococcus aureus (MRSA) right coronary artery (RCA) aneurysm in a 56-year-old male with poorly controlled diabetes and recent complex MRSA bacteremia originating from a skin source. Two months prior, he was treated for multifocal MRSA bacteremia with prostatic abscesses, pulmonary septic emboli, and right-sided endogenous endophthalmitis. He received 8 weeks of appropriate therapy then re-presented with fever and pleuritic chest pain. CT imaging revealed a large complex pericardial effusion and enlarging saccular aneurysm of the RCA with rim enhancement. His course was complicated by cardiac tamponade with evidence of shock, and pericardial window revealed purulent effusion that grew MRSA. He was also found to have multivessel coronary artery disease and underwent ligation of the aneurysm with coronary artery bypass grafting. This case highlights mycotic coronary artery aneurysm as a rare but important complication of MRSA bacteremia.