Thrombolysis and hypercoagulability : relevance to post-thrombolytic events and procedures

21 patients with STEMI were studied. Venous blood samples were collected prior to thrombolysis with streptokinase and at 1, 2, 4, 12, 24, 36 and 48 hours post thrombolysis, and a number of haemostatic and fibrinolytic variables assessed. 20 patients undergoing elective angioplasty were also studied, with samples collected before, and at 1, 2 and 24 hours post-procedure.;Plasma fibrinogen and soluble fibrin were both elevated prior to therapy but fell significantly 4 hours following thrombolysis, rising to normal plasma levels by 36-48 hours. There was a similar fall in plasminogen following treatment. Levels then rose, but by 48 hours were still 50% in the first hour but rose over the subsequent 12 hours to more than twice the pre-thrombolysis level, falling to pre-treatment levels by 36 hours. TAFI is a naturally occurring inhibitor of fibrinolysis. TAFI activity showed a similar pattern to X-oligomer. Platelet activation was measured by expression of P-selectin and GP IIb/IIIa on the platelet membrane, and by the appearance of soluble P-selectin in plasma. Membrane P-selectin fell over the first 4 hours, then increased. GP IIb/IIIa expression rose beyond 4 hours to peak at 36 hours. Levels of soluble P-selectin fell initially, but then rose, peaking at 12 hours.;These data indicate early consumption of both coagulation and fibrinolytic factors immediately following therapy followed by dominance of coagulation and platelet activation over fibrinolysis beyond 12 hours with persistently low levels of plasminogen even at 48 hours.