ACTIVATION OF THE CONTACT PHASE OF THE COAGULATION, OF THE KININ SYSTEM AND OF THE COMPLEMENT CASCADE BY STREPTOKINASE IN ACUTE MYOCARDIAL-INFARCTION

Thrombolytic therapy in acute myocardial infarction is a widely-accept ed and life-saving therapy. However, it is hampered by a considerable reocclusion rate. Furthermore, hypotensive reactions are frequently ob served, especially if the non clot-specific thrombolytic agent strepto kinase is used. Streptokinase increases the pre-existing elevation of thrombin generation in these patients and also activates the factor XI I-contact phase system. Increase of the plasma kallikrein activity and an enhanced bradykinin generation, probably caused by the plasminemia , were described. These changes after streptokinase infusion are paral leled by an activation of the complement cascade. Activation of the co agulation cascade and of the kallikrein-kinin system by streptokinase might be one of the reasons for coronary reocclusions after initially successful thrombolytic therapy in patients with acute myocardial infa rction. Side-effects of bradykinin generation as hypotensive reactions were also observed after streptokinase infusion. These side-effects m ight become more important in the future with increasing use of ACE-in hibiting drugs in patients with coronary heart disease.