Rapidly enlarging mycotic coronary artery aneurysm caused by bacterial seeding involving methicillin-sensitive Staphylococcus aureus and Klebsiella pneumoniae

Published:September 25, 2021DOI:https://doi.org/10.1016/j.jccase.2021.08.010


      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.

      Learning objective

      Although rare, mycotic coronary artery aneurysms (MCAA) should be considered in the differential diagnosis of bacteremic patients presenting with symptoms of acute coronary syndrome. The MCAA diagnosis can be challenging due to nonspecific presentation and examination. Frequent surveillance and tempestive treatment results in favorable outcomes for the patient.


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        • Cohen P.
        • O'Gara P.
        Coronary artery aneurysms: a review of the natural history, pathophysiology, and management.
        Cardiol Rev. 2008; 16: 301-304
        • Hartnell G.
        • Parnell B.
        • Pridie R.
        Coronary artery ectasia. Its prevalence and clinical significance in 4993 patients.
        Heart. 1985; 54: 392-395
        • Abou Sherif S.
        • Ozden Tok O.
        • Taşköylü Ö.
        • Goktekin O.
        • Kilic I.
        Coronary artery aneurysms: a review of the epidemiology, pathophysiology, diagnosis, and treatment.
        Front Cardiovasc Med. 2017; 4: 24
        • Restrepo C.
        • Gonzalez T.
        • Baxi A.
        • Rojas C.
        Infected (“Mycotic”) coronary artery aneurysm: systematic review.
        J Cardiovasc Comput Tomogr. 2020; 14: e99-104
        • Yang E.H.
        • Kapoor N.
        • Gheissari A.
        • Burstein S.
        Coronary and intracerebral arterial aneurysms in a young adult with acute coronary syndrome.
        Tex Heart Inst J. 2012; 39: 380-383
        • Saccà S.
        • Pacchioni A.
        • Nikas D.
        Coil embolization for distal left main aneurysm: a new approach to coronary artery aneurysm treatment.
        Catheter Cardiovasc Interv. 2011; 79: 1000-1003
        • Antileo P.
        • Dauvergne C.
        • Méndez M.
        • Alvarado M.
        • Sepúlveda Ó.
        • Monsalve R.
        • Sandoval J.
        Percutaneous intervention of coronary aneurysm.
        Cardiovasc Revasc Med. 2020; 21: 138-142
        • Jha N.
        • Ouda H.
        • Khan J.
        • Eising G.
        • Augustin N.
        Giant right coronary artery aneurysm- case report and literature review.
        J Cardiothorac Surg. 2009; 4: 18