Acute coronary syndrome with ST segment elevation remains a serious problem in cardiology and often determines the level of in-hospital mortality. Later, the patient’s admission to reperfusion therapy can lead to deterioration of the immediate and long-term results of treatment. The most difficult problem with percutaneous reperfusion therapy STEMI patients is no-reflow syndrome, i.e. the absence of myocardial perfusion after restoration of the arterial blood flow. Taking into account the data of the clinical case, no-reflow syndrome can be diagnosed even when the coronary artery is open (after spontaneous opening), under the presence of visible parietal thrombi and after long period of complete obstruction of the vessel lumen. However, the full restoration of blood flow is necessary and in the later period (up to 24 hours from the onset of symptoms) in the presence of the clinic ischemia and lack of positive dynamics of ECG. As shown in the illustrated clinical cases, restoration of blood flow in the infarct-related coronary artery, even in the presence of the syndrome «no-reflow» is able to restore myocardial function during short period of observation.