Rapidly Enlarging Mycotic Coronary Artery Aneurysm Caused by Bacterial Seeding Involving Methicillin-sensitive Staphylococcus Aureus and Klebsiella Pneumoniae


West Florida


Regional Medical Center Bayonet Point

Document Type

Case Report

Publication Date



mycotic aneurysm, coronary artery aneurysm, Klebsiella pneumoniae, Staphylococcus aureus


Bacterial Infections and Mycoses | Cardiology | Cardiovascular Diseases


Coronary artery aneurysms are uncommon. A rare subcategory caused by infectious etiologies are called mycotic coronary artery aneurysms (MCAA), which have an exceedingly high mortality rate. In this report, we present a rare case of a rapidly expanding MCAA involving Staphylococcus aureus and Klebsiella pneumoniae affecting the left circumflex artery. Per our literature review, MCAA involving K. pneumoniae co-infection or superinfection have rarely, if ever, been documented. The aneurysm was discovered when the patient underwent coronary angiography for non-ST-elevation myocardial infarction. She was treated for bacteremia and upon reevaluation the aneurysm had grown approximately three times the original size. The patient had an aneurysmectomy with coronary artery bypass grafting due to the enlargement and size of the aneurysm. By highlighting this life-threatening disease, we hope to shed light on rare causes of MCAA and the importance of appropriate treatment.

Publisher or Conference

Journal of Cardiology Cases