This case illustrates acute myocardial infarctionÂ caused by coronary embolism (CE). Although it is not seen often in a daily practice, the occurrence of coronary embolism (CE) as a mechanism of STEMI in the acute setting ranges from 2.9 to 4 percent.2,3 That means that roughly one out of thirty STEMI cases would have an embolic origin.
Among all the etiologies of CE,Â atrial fibrillation leads, constituting 28 to 73 percent of all the cases.2,3 Other causes include intracardiac tumors, dilated cardiomyopathy, left ventricular aneurysms, and Iatrogenic embolism during interventional procedures (air bubbles, thrombi, calcium deposits). Infective emboli with endocarditis is one of the least common etiologies and is seen in only 3.8 to 7.5 percent of all embolic STEMIs.2,3 Recognition of CE as etiology for a STEMI is important from a tactical and prognostic standpoint. Since there is no underlying atherosclerosis with plaque rupture, these cases are best managed by PTCA rather than deployment of stents. With high clinical suspicion of primary CE, we might suggest performing additional work up to completely rule in/rule out this etiology (screening for coagulopathies, work-up for occult arrhythmias/infectious foci/malignancies, imaging looking for the origin of embolus). From a prognostic standpoint, Popovic et. al. showed that coronary embolism was associated with a higher risk of all-cause mortality (HR 4.87; CI 2.52-9,39; P < 0.0001),3 although this can be attributed to severe primary comorbidities (mainly malignancies) leading to unfavorable outcome.
- When thrombus is identified during intervention of STEMI, PCI is preferred to thrombectomy.
- Coronary embolization accounts for 3 to 4 percent of STEMIs.
- Endocarditis is among the least common causes of acute coronary embolization but should be considered in patients who are at high risk for this condition. A careful history is critical to raise clinical suspicion and order more definitive studies such as TEE.