Intrahospital switch of the P2Y12 inhibitors in patients with ST segment elevation myocardial infarction in ‘real-life’ clinical practice: the effect on the functional activity of thrombocytes and thrombocytopoiesis, prognostic value

Aim . To assess the P2Y 12 inhibitors switch in patients ST segment elevation myocardial infarction (STEMI) in real-life’ clinical practice, evaluate the functional activity of thrombocytes and thrombocytopoiesis and determine the clinical and prognostic value of P2Y 12 inhibitors switch in the framework of dual antiplatelet therapy in patients with STEMI. Material and methods . We conducted local, stratified, prospective study in which were involved 101 patients, hospitalized no later than 12 hours after the STEMI manifestation. The antiplatelet therapy (APT), prescribed by the physicians at the pre-hospital and inpatient phases of treatment, was analyzed. Functional activity of thrombocytes, levels of thrombopoietin (THPO), stromal cell-derived factor 1 (SDF1) and thrombopoietic receptor (MPL) were investigated. The minimum observation period was 2 years. Death and repeated hospitalizations due to cardiovascular causes were monitored. Results . P2Y 12 inhibitors were switched in 32,7% of patients with STEMI. In the hospital, clopidogrel, which was prescribed at the prehospital phase, was replaced with ticagrelor (early APT escalation) — 22,8%. Patients with early APT escalation by the seventh day had significantly greater inhibition of platelet aggregation activity parameters (slope of the aggregation curve, latent aggregation time and area under the aggregation curve). Activation of the collagen-induced platelet aggregation was detected. With the early escalation of APT, the THPO level was statistically significantly higher, both on the second and on the 7th day measurements: 256,2 (209,0; 396,8) pg/ml vs 137,5 (105,7; 179,1) pg/ml (p=0,000) and 283,4 (228,9; 334,3) pg/ml vs 226,5 (163,2; 287,3) pg/ml (p=0,045), respectively. The frequency of reaching the combined endpoint (death + re-hospitalization) was 7,9% in patients who had a P2Y12 switch, and 28,1% in patients who did not change the P2Y 12 blocker. Conclusion . In actual clinical practice, patients with STEMI had the most frequent early APT escalation, which was characterized by a more significant suppression of adenosine diphosphate-induced platelet aggregation and secretion than in patients without P2Y 12 inhibitors switch, but with activation of collagen-induced aggregation. An increase in thrombocytogenesis was revealed in early replacement of clopidogrel by ticagrelor. Intrahospital replacement of the P2Y 12 inhibitor in patients with STEMI was accompanied by a decrease in the two-year death risk and repeated hospitalizations.