RELATIONSHIP OF TISSUE FACTOR PATHWAY INHIBITOR ACTIVITY TO PLASMA-LIPOPROTEINS AND MYOCARDIAL-INFARCTION AT A YOUNG AGE

Tissue factor pathway inhibitor (TFPI) activity was quantified in two cohorts of young male post-infarction patients and in population-based control subjects to explore the relationships between TFPI activity a nd plasma lipoproteins and to address the issue of coordinate regulati on of factor VII and TFPI in hyperlipidaemia and premature coronary he art disease (CHD). Participants were investigated in the fasting state and after an oral fat load. Basal TFPI activity and factor W antigen (VIIag) levels were found to be increased in the patients (TFPI activi ty 1.25+/-0.23 vs 1.17+/-0.20 U/ml, p <0.05; VIIag 537.7+/-127.7 vs 47 9.4+/-93.4 ng/ml, p <0.001). The parallel increase was accounted for b y patients with hypertriglyceridaemic lipoprotein phenotypes. In contr ast, the level of activated factor VII (Wa) neither differed significa ntly between patients and controls, nor between patients with differen t lipoprotein phenotypes. The elevated TFPI activity in the patients w as closely associated with the plasma level of dense low density lipop rotein (LDL) particles (r = 0.46, p <0.001) and with the plasma concen tration of the small, dense high density lipoprotein (HDL) subspecies HDL(3b) (r = 0.34, p <0.01).