THE ROLE OF FIBRINOGEN IN SERUM AND PLASMA BLOOD TENSIO- AND RIOMETRY IN CORONARY HEART DISEASE AND VALVE LESIONS PATIENTS

Abstract

Background. Insight into blood viscosity in terms of its physical and biochemical properties carries significant clinical value. By understanding the relationship between the physical properties of blood and physiology, a potentially powerful tool for diagnosing early signs of many diseases can be discovered. Purpose. To identify the effect of fibrinogen on tensio- and rheometric characteristics of blood plasma and serum in patients with coronary heart disease and with mitral and/or aortic valve disease. Materials and methods. Prospective non-randomized study. The study of dynamic, equilibrium surface tension and viscoelastic modulus was performed by the pendant drop method using a PAT-1 device (Sinterface Technologies, Germany). We measured parameters characterizing the surface tension and dilatation rheology of blood serum such as: dynamic surface tension at an adsorption time of 100 s (γ), equilibrium surface tension (γ ∞) (adsorption time 2500 s), viscoelastic modulus |E|, and phase angle (φ) at frequencies of 0.1 and 0.01 Hz. All patients under study were divided into 3 groups. The healthy volunteers (30 subjects) without chronic diseases and active complaints aged 49 to 78 years (mean age, 61.1±1.1 years) comprised the comparison group (group 1). Group 2 - 40 patients with coronary heart disease (CHD) aged 49 to 77 years (mean age 62.2±1.3 years) who underwent bypass surgery to treat atherosclerotic coronary vessels (2 to 5 bypasses). Group 3 - 30 patients with cardiac mitral and/or aortic valve lesions aged 52 to 78 years (mean age 61.3±1.2 years). They underwent mitral and/or aortic valve replacement with mechanical prostheses. The most common pathophysiological syndrome in patients due to coronary artery or heart valve lesions was chronic heart failure (CHF) (stage 2A-2B according to Vasilenko-Strazhesko classification). Results. Characteristic γ100s of blood serum and plasma had significant difference in both patients’ groups, possibly due to the role of coagulation and anti-coagulation system proteins’ role in dynamic surface tension of plasma in a shorter timeframe (up to 100 s.). The increase in Δγ100s in both patients’ groups by day 7 of the postoperative period indicates an increasing dynamic surface tension of serum compared to plasma. Plasma of perioperative patients does not differ from the comparison group by its surface-equilibrium properties. Accordingly, the Δγ∞s values in groups 1 and 2 both before surgery and on days 1 and 7 of the postoperative period are almost identical, pointing to no difference in the amount of surfactants tending to adsorb on the droplet surface. Alterations of viscoelastic modulus |E| and phase angle (φ) at 0.1 and 0.01 Hz in the perioperative period indicate changes in qualitative and quantitative characteristics of circulating blood with variation in individual homeostasis characteristics, resulting in an increase in surface elasticity combined with an almost unchanged surface viscosity. Conclusion. Dynamic and equilibrium surface tension parameters in patients’ plasma differ from those in serum due to the presence of fibrinogen and other proteins of the blood coagulation system.

Keywords

• fibrinogen
• tensio- and rheometry of serum and plasma
• coronary heart disease
• mitral valve defect
• aortic valve defect