Introduction. Worldwide myocardial infarction (MI) is one of the main causes of morbidity and mortality. Thanks to advances in modern cardiology we achieved a significant reduction in mortality and the incidence of fatal complications of acute Q-wave MI. However, keeping in mind the pathogenetic features of myocardial defeat of the left ventricle (LV cavity dilation and thinning at the focus of myocardial infarction), which increase the risk of left ventricular aneurysm development and parietal thrombus formation, it is impossible to reduce significantly the risk of these serious complications development. Post-infarction left ventricular aneurysm, extremely unfavorable prognostic factor complicates the course of Q-wave myocardial infarction in 30% of cases. The likelihood of parietal clot development in the anterior apical localization of aneurysms is 32%. The reasons of parietal clot formation are varied and are not fully disclosed, that is responsible for the relevance of this study. Aim: to investigate the serum level of protein C, von Willebrand factor, the expression of vascular adhesion molecules sVCAM-1, platelet aggregation properties and to evaluate their relationship with the structural and functional performance of the heart in patients with acute Q-wave myocardial infarction with aneurysm and parietal thrombus of LV. Methods. 110 patients (67 men and 43 women), mean age - 63,2 ± 5,7 years, with a diagnosis of acute Q-wave myocardial infarction were involved into the study. The first group included 72 patients with postinfarction left ventricular aneurysm, the second - 38 patients with postinfarction aneurysm and parietal thrombus of LV. Serum levels of protein C, von Willebrand factor, the expression of vascular adhesion molecules sVCAM-1, platelet aggregation properties were studied and their relationship with the structural and functional performance of the heart were evaluated. Results. There were revealed high activity of the key elements of the blood coagulation system, responsible for the formation of parietal blood clots on the background of low levels of protein C, which leads to an imbalance of coagulation-anticoagulation-fibrinolysis towards coagulation and suppression of fibrinolysis, associated with thrombosis. Vascular adhesion molecule sVCAM-1 can be regarded not only as an indicator reflecting the state of the blood coagulation system, but also as a marker of immunoinflammatory reactions and endothelial dysfunction, as an increase in their expression due to the increased systemic secretion of proinflammatory cytokines. Activation of immunoinflammatory reactions confirmed by the increase in serum levels of immune system mediators such as fibrinogen and prothrombin. Higher levels of von Willebrand factor is a marker of immune inflammation on a background of endothelial dysfunction. Synergies increase of fibrinogen and von Willebrand factor indicates a high propensity to parietal thrombus formation. Conclusion. It was found that in patients with Q-wave myocardial infarction, complicated by formation of acute aneurysm and parietal thrombus of LV, postinfarction heart remodeling processes are characterized by dilation of the left heart chambers and eccentric left ventricular hypertrophy, a violation of local contractility by dyskinetic type, parietal thrombus formation, the development of diastolic dysfunction of type II and closely associated with high procoagulant and aggregation serum potential with decreased activity of natural anticoagulants on the background of immunoinflammatory reactions and activation of endothelial dysfunction.