Contributions
Abstract: PB2511
Type: Publication Only
Background
Disturbances in the plasma levels of tissue plasminogen activator (t-PA) and its inhibitor (PAI-1) as well as in fibrinolysis have been implicated in the pathogenesis and development of ischemic heart disease, particularly acute coronary syndrome.
Aims
The main goal of the current study was to compare some hemostasis parameters of the patients with acute myocardial infarction and patients with unstable angina.
Methods
Blood plasma was taken from 35 healthy donors and 9 patients with acute myocardial infarction (AMI), 14 patients with new onset unstable angina (NOUA), 21 patients with progressive unstable angina (PUA). Plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor (vWF) were measured by enzyme-linked immunosorbent assays. Soluble fibrin monomer complex (SFMC) was determined using the phosphate method with 0.1 M phosphate-buffered saline containing sodium citrate and 0.2% 6-aminohexanoic acid with following determination (Zaichko N.V., 2006).
Results
Tissue-type plasminogen activator is an enzyme that converts the inactive proenzyme plasminogen to the active protease plasmin – the main executer of fibrinolysis. The obtained data showed that the plasma concentration of t-PA was in 1.43 times lower in the patients with AMI and NOUA than in the group of the healthy donors. The decreased of plasma level of t-PA may reduce fibrinolytic activity and attenuate removal of the thrombus and may ultimately lead to acute myocardial infarction in some patients with unstable angina. On the other hand, the t-PA level in patients of PAU group was at the control level. The catalytic activity of t-PA in the bloodstream is mainly regulated by the binding with some inhibitors. Therefore, the plasma level of the primarily inhibitor PAI-1 was also estimated.
There were significant elevations of PAI-1 in patients with AMI, NOUA and PUA. According to the obtained results the level of PAI-1 was in 16 times higher than the control value for 30% of patients with NOUA and for 70% of patients with PUA. For all the patients of AMI group PAI-1level was in 11 times higher than this in the group of the healthy donors. The elevated level of PAI-1 results in deficient plasminogen activation and is strongly associated with a predisposition to thrombosis. To estimate the thrombotic conditions and the degree of blood coagulation system activation SFMC concentration was determined. SFMC is formed in the early-activated state of blood coagulation and its appearance is expected to be a parameter for the diagnosis of thrombus formation. The conducted study revealed significant elevation of SFMC level in all patients of AMI group (in 10.6 times), NOUA group (in 12.6 times) and in 60% of the patients with PUA (in 11.5 times). Despite the well-known fact the involvement of endothelial dysfunction in the pathogenesis of cardiovascular disease no significant differences of the vWF's concentration in patients with AMI and NOUA have been detected. In contrast, about 60% of the patients with PUA have plasma level of vWF in 1.36 times higher comparing to the group of healthy donors.
Conclusion
The obtained findings suggest the strong impairment of the hemostasis balance in patients with acute coronary syndromes that appears as elevation of level of PAI-1, depletion of level of t-PA and accumulation of SFMC.
Session topic: 35. Thrombosis and vascular biology & translational Research
Keyword(s): Acute coronary syndrome, Fibrinolysis, Hemostasis
Abstract: PB2511
Type: Publication Only
Background
Disturbances in the plasma levels of tissue plasminogen activator (t-PA) and its inhibitor (PAI-1) as well as in fibrinolysis have been implicated in the pathogenesis and development of ischemic heart disease, particularly acute coronary syndrome.
Aims
The main goal of the current study was to compare some hemostasis parameters of the patients with acute myocardial infarction and patients with unstable angina.
Methods
Blood plasma was taken from 35 healthy donors and 9 patients with acute myocardial infarction (AMI), 14 patients with new onset unstable angina (NOUA), 21 patients with progressive unstable angina (PUA). Plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor (vWF) were measured by enzyme-linked immunosorbent assays. Soluble fibrin monomer complex (SFMC) was determined using the phosphate method with 0.1 M phosphate-buffered saline containing sodium citrate and 0.2% 6-aminohexanoic acid with following determination (Zaichko N.V., 2006).
Results
Tissue-type plasminogen activator is an enzyme that converts the inactive proenzyme plasminogen to the active protease plasmin – the main executer of fibrinolysis. The obtained data showed that the plasma concentration of t-PA was in 1.43 times lower in the patients with AMI and NOUA than in the group of the healthy donors. The decreased of plasma level of t-PA may reduce fibrinolytic activity and attenuate removal of the thrombus and may ultimately lead to acute myocardial infarction in some patients with unstable angina. On the other hand, the t-PA level in patients of PAU group was at the control level. The catalytic activity of t-PA in the bloodstream is mainly regulated by the binding with some inhibitors. Therefore, the plasma level of the primarily inhibitor PAI-1 was also estimated.
There were significant elevations of PAI-1 in patients with AMI, NOUA and PUA. According to the obtained results the level of PAI-1 was in 16 times higher than the control value for 30% of patients with NOUA and for 70% of patients with PUA. For all the patients of AMI group PAI-1level was in 11 times higher than this in the group of the healthy donors. The elevated level of PAI-1 results in deficient plasminogen activation and is strongly associated with a predisposition to thrombosis. To estimate the thrombotic conditions and the degree of blood coagulation system activation SFMC concentration was determined. SFMC is formed in the early-activated state of blood coagulation and its appearance is expected to be a parameter for the diagnosis of thrombus formation. The conducted study revealed significant elevation of SFMC level in all patients of AMI group (in 10.6 times), NOUA group (in 12.6 times) and in 60% of the patients with PUA (in 11.5 times). Despite the well-known fact the involvement of endothelial dysfunction in the pathogenesis of cardiovascular disease no significant differences of the vWF's concentration in patients with AMI and NOUA have been detected. In contrast, about 60% of the patients with PUA have plasma level of vWF in 1.36 times higher comparing to the group of healthy donors.
Conclusion
The obtained findings suggest the strong impairment of the hemostasis balance in patients with acute coronary syndromes that appears as elevation of level of PAI-1, depletion of level of t-PA and accumulation of SFMC.
Session topic: 35. Thrombosis and vascular biology & translational Research
Keyword(s): Acute coronary syndrome, Fibrinolysis, Hemostasis