A thrombotic tendency in patients with infective endocarditis.

An attempt was made to evaluate a thrombotic tendency in cases of infective endocarditis (IE) from the viewpoint of the changes of platelets and coagulo-fibrinolysis. Qualitative changes of platelets by thrombi formation were detected by showing activated responses of platelets to adenosine diphosphate or collagen and by showing a high level of plasma beta-thromboglobulin which is released by platelets during aggregation. A mild hypercoagulable state without acceleration of fibrinolysis was also detected by showing low levels of plasma antithrombin III which is the most potent antithrombin in the blood and normal levels of plasma alpha 2-plasmin inhibitor in the blood. From above findings, it was concluded that a thrombotic tendency in cases of IE was clearly detected by qualitative changes of platelets by thrombi formation and by mild hypercoagulability without acceleration of fibrinolysis.