Evaluation of platelet function and tissue plasminogen activator activity in ischemic heart disease depending on concurrence with hyperlipoproteinemia and aspirin therapy

Platelet activation, impairment of fibrinolysis and dyslipidemia are important factors in the pathogenesis and progression of ischemic heart disease. Aspirin therapy will reduce platelet activation both by its negative effect on platelet aggregation (SPA) and by inhibition of granule release which liberates such mediators as platelet factor 4 (PF4) and plasminogen activator inhibitor 1 (PAI-1). The present study was performed in 57 patients with ischemic heart disease (IHD), divided into groups depending on coexistent hyperlipoproteinemia (HLP) and aspirin treatment. The control group included 21 healthy individuals, matched for age and sex. Parameters of hemostasis (SPA, PF4, PAI-1) and concentration of lipid fractions (TC, TG, LDL, HDL) were measured in plasma. Increased PF4 levels were found in all groups with IHD, irrespective of hyperlipoproteinemia or aspirin treatment. Enhanced SPA and higher PAI-1 were limited to group IHD-HLP without aspirin. Highest PAI-1 activities were observed after stimulation of platelets in vitro. In conclusion, patients with IHD and hyperlipoproteinemia presented most pronounced platelet activation and impairment of fibrinolysis. Aspirin had a beneficial effect on these changes. Lower activities of PAI-1, in patients treated with aspirin, can be ascribed to its reduced release from platelets. Aspirin did not satisfactorily reduce the level of PF4, although it strongly inhibited SPA.