PB0873 - Platelet parameters and platelet aggregation in patients with COVID-19 and acute coronary syndrome

Background: Arterial thrombosis can complicate the course of COVID-19, platelets playing a significant role in the thrombosis initiation and progression.

Aims: To determine platelet parameters and aggregation function in patients with COVID-19 complicated by acute coronary syndrome.

Methods: COVID-19 was confirmed by polymerase chain reaction, and lung damage was assessed by computed tomography. Acute coronary syndrome (ACS) was diagnosed by the clinical presentation, serum troponin levels, electrocardiogram and coronary angiogram. Blood parameters were assessed by Mindray BC-6800Plus automatic hematology analyzer. ChronoLog 700 was used to assess platelets aggregation with adenosine diphosphate, collagen, and epinephrine. All patients received standard therapy for the index conditions. Statistical analysis was performed in the Statistica environment. Qualitative indicators were compared using Fisher's exact test, and quantitative indicators were compared using Kruskal-Wallis test. The study was approved by the Local Ethics Committee of the Ural State Medical University by protocol No. 9 of October 22, 2021.

Results: COVID-19 patients without ACS took antiplatelet therapy less frequently and ACS patients without COVID-19 took anticoagulant therapy less frequently than other groups (Table 1). There were no differences between the groups in the level of red blood cells and white blood cells. Platelet count, mean platelet volume (MPV), platelet distribution width (PDW), platelet larger cell ratio (P-LCR), platelet aggregation with ADP, collagen and epinephrine were higher in patients with COVID-19 without ACS (Table 2).

Conclusion(s): The blood platelets count, as well as platelets functional activity, depends on the presence of antiplatelet therapy in the studied groups. The persistence of high platelet aggregation activity in patients with COVID-19 in the absence of antiplatelet therapy may be a risk factor for thrombotic complications.