LAUSR

Enhanced activation of endogenous fibrinolysis in ST-elevation myocardial infarction (STEMI) patients is the main cause of spontaneous reperfusion of the infarct-related artery (IRA) in the acute period. Whether this enhanced activation remains in the deferred period of myocardial infarction remains unclear. The main purpose of our work was to analyze the process of clot formation and endogenous fibrinolysis in patients with a history of myocardial infarction. We included 51 patients with a history of myocardial infarction (median, 35 months). Of these patients, 19 had a spontaneous reperfusion of the IRA (SR group) during the index event, and 32 had a total occlusion of the IRA (occlusion group). We assessed parameters of clot formation and endogenous fibrinolysis using thromboelastometry and a thrombodynamics assay. We analyzed endothelial function using the flow-mediated dilation test (FMD). The process of clot formation was more active in the occlusion group than in the SR group. Thus, the initial, mean, and total clot velocity times were significantly higher in the occlusion group than in the SR group: 57.2 mcm/min vs. 60.25 mcm/min; 28,1 mcm/min vs. 31.9 mcm/min; and 28.7 mcm/min vs. 31.9 mcm/min, respectively; p<0.01. The clot size was much bigger in the occlusion group than in the SR group (1,190.5 mcm vs. 1,315 mcm; p<0.01). No differences in endogenous fibrinolysis parameters were observed between the two groups. Endothelium function was better in the SR-group than in the occlusion group (FMD 17.4% vs 11.3%, p<0.01). STEMI patients with occlusion of the IRA and those with spontaneous reperfusion remain different in clot formation and endothelial function even after many years. Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was supported by the Russian Science Foundation grant