Platelet aggregation in patients with chronic heart failure in a "vortex" flow
Authors: Trubacheva OKSANA , Kologrivova IRINA , Suslova TATYAN 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Исследование выполнено в рамках фундаментальной темы НИИ кардиологии АААА-А15-115123110026-3.
Platelet aggregation mechanisms are studied using standard methods without taking turbulence into account. However, in cardiovascular diseases, the blood rheology changes, and the parameters of the turbulent flow acquire strong prothrombotic effects. The adhesion of several platelets creates a "snowball" effect with platelet hyperaggregation, leading to rapid vessel occlusion. Thus, the study of platelet aggregation in patients with cardiovascular diseases in conditions of creating a "vortex" flow in platelet-rich plasma is very relevant.

Objective
to study the effect of "vortex" flow in platelet-rich plasma on spontaneous and epinephrine-induced platelet aggregation in patients with CHF. Material and method. We studied 15 patients (75% of them men) with CHD, having CHF I-III FC. Platelet aggregation activity was studied using a turbidimetric method using a laser analyzer (220 LA "NPF Biola", Russia). Platelet aggregation activity in platelet-rich plasma (BTP) was estimated by light transmission curves in % and average aggregate size in relative units (Rel. units), with the inducer epinephrine in concentrations of 2 and 10 mg/ml, with constant stirring at 800 rpm. The same parameters were evaluated byour ownproposed approach with a creation ofa "vortex" plasma flow, which were achieved by changing the mixing rate of BTP from 0 to 800 rpm. Aggregation data is presented as a median with an interquartile range (Me (Q1; Q3)). Statistical data processing was performed using SPSS packages (version 19). The differences were considered significant at a significance level of p &lt; 0.05. Results. In patients with CHF, the indicators of spontaneous aggregation measured by the standard method were 3.1 (1.5; 4.0) % and 1.7 (1.1; 2.0) Rel. units. Under the conditions of a"vortex" flow, the aggregate size increased to 5.4 (3.2; 6.1) Rel. units(p = 0.04). The indicators of standard epinephrine-induced aggregation at a concentration of 2 mg/ml were 46.7 (35.8; 66.2) % and 15.0(11.4; 18.9) Rel. units, and when the mixing speed was changed from 0 to 800 rpm, the indicators increased to 52.7 (41.3; 76.5) % (p = 0.003) and 19.4 (17.3; 20.6) Rel. units(p = 0.04). In conditions of increased epinephrine concentration of 10 mg/ml, the indicators were 52.5 (41.9; 74.5) % (p = 0.03) and 15.8 (12.2; 18.4) Rel. units. Under the conditions of"vortex" flow, aggregation indicators were 75.4 (62.0; 80.5)% (p = 0.04), and the size of aggregates increased to 356.0 (230.5; 462.5) Rel. units. Conclusion. Standard methods for studying of platelet aggregation are not always sufficient to detect an increased pro-aggregative potential of platelets. The proposed method for creationof "vortex" flow conditions showed an increase in the size of platelet aggregates and the degree of aggregation against the background of increased epinephrine concentration in patients with chronic heart failure, which proves its effectiveness in detecting platelet hyperaggregation.