Comparison of fibrinolytic activity in the femoral vein and the right atrium

Local fibrinolytic activity in leg veins has not been completely explored. Since the blood in the right atrium is a mixture of venous blood supplied from the whole body, the fibrinolytic activity in the right atrium may be used as a reference value to which local values can be compared in order to identify local hyperfibrinolysis or hypofibrinolysis. We compared fibrinolytic parameters [tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), euglobulin clot lysis time] measured in the femoral vein with those in the right atrium. The blood samples were obtained during right heart catheterization of 51 patients. No differences in t-PA antigen [9.6 ng/ml (6.6–11.9 ng/ml) versus 8.1 ng/ml (6.7–11.3 ng/ml)] [median (interquartile range)] and PAI-1 antigen [9.3 ng/ml (7.1–16.0 ng/ml) versus 8.4 ng/ml (5.5–14.3 ng/ml)] levels were found, whereas t-PA activity was significantly higher [183 IU/ml (39–1097 IU/ml) versus 92 IU/ml (5–680 IU/ml), P < 0.05], PAI-1 activity significantly lower [7.2 IU/ml (5.1–10.2 IU/ml) versus 7.9 IU/ml (5.8–10.3 IU/ml), P < 0.05], and the euglobulin clot lysis time was significantly shorter [6.2 1000/min (4.8–10.0 1000/min) versus 5.5 1000/min (4.1–9.1 1000/min), P < 0.05] in the femoral vein compared with the right atrium. In conclusion, our results show that local fibrinolytic activity in the femoral vein is higher than in the right atrium, and thus demonstrate that increased local fibrinolysis is present in leg veins.