Acute myocardial infarction caused by coronary embolism from infective endocarditis

Background: Identifying an acute myocardial infarction caused by a non-atherosclerotic process can have consequences on the short- and long-term management of the disease.

Case reports: In the first case reported, a 39-year-old woman with a history of hypertension, diabetes, end-stage renal disease, deep vein thrombosis, and a recent hospitalization for staphylococcal bacteremia presented to the Emergency Department (ED) with acute onset of chest pain and shortness of breath. Her electrocardiogram (ECG) showed findings of an ST-segement elevation lateral wall acute myocardial infarction (AMI). The patient's condition worsened in the ED, and thrombolytic therapy was initiated. The patient subsequently had a coronary catheterization that illustrated an irregular mitral valve and abrupt occlusions in the left anterior descending artery, suggestive of coronary embolism from a mitral valve source. This patient was later treated with intravenous antibiotics and mitral valve replacement. In the second case reported, a 56-year-old man with a history of hypertension, diabetes, and end-stage renal disease presented to the ED with shortness of breath, fever, and chest pain. His ECG was significant for ST-segment elevation in the lateral leads, suggestive of an AMI. This patient had a history of positive blood cultures in a previous admission as well as an echocardiogram revealing an aortic valve vegetation. Given the high suspicion for an infective endocarditis causing an embolic event that in turn led to the myocardial infarction, thrombolytics were withheld in the ED and the patient was transported for coronary catheterization. The coronary angiogram demonstrated abrupt cutoffs at the distal left anterior descending artery and distal left posterior descending artery suggestive of an embolic occlusion of these vessels. He was subsequently treated with intravenous antibiotics and aortic valve replacement.

Conclusions: These two cases illustrate the importance of broadening our differential in the causes of AMI. In these cases, the recognition of an embolic event from infective endocarditis as the cause of the acute coronary syndrome allowed physicians to direct their interventions to optimize the appropriate care for each patient.