The paper describes a patient admitted to the Emergency Cardiology Department, A.L. Myasnikov Institute of Clinical Cardiology, for diagnosed ST-segment elevation acute coronary syndrome. At the prehospital stage, the patient received ineffective thrombolytic therapy; percutaneous coronary intervention was made at the Department of X-ray Endovascular Diagnostic and Treatment Methods of the Institute 3.5 hours after disease onset. Repeated thrombus aspirations from the infarction-related artery were carried out, which could have a good angiographic pattern. His medical record shows that the patient has been suffering from persistent atrial fibrillation for a long time. There is also evidence for transient ischemic attacks in 2010 and 2011. The fact that there are no coronary artery stenoses after thrombus removal could suspect the thromboembolic genesis of myocardial infarction.