Noninvasive markers of intravenous streptokinase coronary thrombolysis

Early creatine kinase (CK) enzyme peaking, rapid electrocardiographic (EKG) changes toward normal, reperfusion arrhythmias, pain disappearance, and 201thallium myocardial scintigraphy appear useful to identify the success or failure of intravenous (i.v.) thrombolytic therapy in patients with acute myocardial infarction (AMI). Most patients with AMI are treated currently in community hospitals which do not possess coronary angiographic capabilities. Recent evidence indicates that early intravenous streptokinase results in coronary thrombolysis in the majority of patients treated. A composite of noninvasive markers of coronary reperfusion was assessed in two similar patients with transmural AMI. One received intravenous streptokinase (STK) 750,000 U 90 min after AMI onset; the other received intracoronary (i.c.) STK 4000 U/min 140 min after onset. Within one hour each showed a sudden change in elevated EKG ST segments toward normal, followed by frequent premature ventricular beats and pain disappearance. Posttreatment angiograms documented recanalization of each infarct-related artery. Early CK peaking occurred at 10 hours after the onset of chest pain in the first patient and at 12 hours in the second. This contrasts with delayed CK peaking at 26.4 hours among 384 patients reviewed with untreated AMI. Early CK peaking appears the most accurate indirect marker of successful coronary thrombolysis.