Platelet functional pools under pharmacological suppression of aggregation in ST segment elevation myocardial infarction

The purpose of the study is to investigate clinical significance of peripheral pool platelets functional heterogeneity, assessed with combination of collagen and ADP, under pharmacological suppression of platelet aggregation in acute coronary syndrome. Material and Methods. The study involved 374 patients with acute coronary syndrome (ACS). Functional activity of platelets (FAT) was studied on the first, the 7th and 30th days after ACS manifestation in the whole blood by impedance and luminescent aggregometry. The functional heterogeneity of platelets was studied using our own method with an estimate of AAk (functional subpopulation of platelets aggregation (cluster II)), ASk (the functional subpopulation of platelets secretion (cluster II)) and ДА (a parameter of platelets functional heterogeneity). The follow-up period was 24 months after ACS manifestation. Results. In the study sample ADP- and collagen-induced platelet aggregation remained almost constant during the whole observation period. It was established that in patients treated with double antiplatelet therapy parameters of functional platelet heterogeneity statistically significantly decreased by the seventh day of observation: ЛАк 2(0; 3)vs 1 (0; 2) Ohm, p=0,049; AS 0.26 (0.15; 0.47) vs 0.19 (0; 0.26) nmol, p=0.07. The excess of ЛАР measured on the second day after ACS manifestation, a threshold of 2 Ohms, was associated with a significant increase in the 30-day risk of rethrombotic events (HR 1.8; Cl 1.2; 3.1). Conclusion. The dynamics of platelet functional heterogeneity was revealed in patients with acute coronary syndrome treated with double antiplatelet therapy. A high degree of platelet functional heterogeneity in patients with acute coronary syndrome was associated with a significant increase in the 30-day risk of rethrombotic events.