Early detection of coronary artery patency after thrombolysis by determination of the MM creatine kinase isoforms in patients with acute myocardial infarction. PRIMI Study Group.

To evaluate the role of MM creatine kinase isoforms in detecting infarct vessel patency in 84 patients with acute myocardial infarction, total creatine kinase, MB creatine kinase, and MM isoforms were determined at the start of thrombolytic therapy and 30, 60, and 120 minutes later. Enzyme data were related to the reperfusion grade of the infarct artery, which was assessed by angiography 60 and 90 minutes after the start of thrombolysis. In 50 patients the infarct vessel was found patent at 60 and at 90 minutes after thrombolysis; in 19 patients it was occluded at both time points. In contrast to the patients with a persistently occluded infarct artery, in the patient group with a patent infarct vessel total creatine kinase and MB creatine kinase increased significantly at 60 minutes after the start of thrombolysis and MM3 creatine kinase activity and the ratio MM3:MM1 had already increased at 30 minutes after the start of thrombolytic therapy. The increases from baseline of creatine kinase and creatine kinase MB activity were significantly higher 120 minutes after the start of thrombolysis; increases of creatine kinase MM3 and the ratio of MM3:MM1, however, by 60 minutes after the start of thrombolysis were already increased compared with the increases in enzyme activity in patients with an occluded artery. Thus the rise in MM3 creatine kinase and the ratio of MM3:MM1 can be used for early detection of reperfusion after intravenous thrombolytic therapy in acute myocardial infarction.