Coronary thrombus in ST elevation myocardial infarction and atrial fibrillation

Coronary embolization is a rare cause of acute myocardial infarction (AMI) and few descriptions are found in the literature. Since atrial fibrillation is a known cause of systemic embolization our aim was to investigate the incidence of globular filling defects suggesting embolization in patients presenting with atrial fibrillation (AF) and ST elevation AMI with single vessel disease. We retrospectively analyzed all patients from our data base between 2002 and 2011 (2,067 patients) presenting with AF, AMI and single vessel disease and compared them to a randomly chosen control group with AMI, single vessel disease and in sinus rhythm. Of the 14 patients meeting the above criteria, 12 had a globular filling defect at the occlusion site (86%), in comparison to only 8 of 30 in the control group (27%) (p < 0.01). The study group patients were older, more frequently female, diabetic, dyslipidemic and hypertensive and had more valvular heart disease, while patients in the control group were more often smokers. Almost all the patients in the study group were either not receiving anticoagulation or inadequately anticoagulated. Atrial fibrillation was found to be the only factor independently associated with a globular filling defect on multivariable analysis (OR 34, 95% CI: 2-72). In conclusion, a globular filling defect is a common finding in patients with AF and single vessel disease presenting with AMI, probably as a result of embolization.