[Intracoronary thrombolysis in acute myocardial infarction].

To lyse intracoronary (IC) thrombi, coronary angiography was performed for 36 patients with acute myocardial infarction who were admitted within 12 hours of the onset of symptoms. Their average age was 59.6 years. Twenty-four patients (66.7%) had total occlusions of the infarct-related coronary artery, and 12 patients (33.3%) had severe atherosclerotic stenosis without occlusion (group A = Stenosis). In 19 of the 24 patients (79.2%) with total occlusion, IC infusion of urokinase (UK) at a rate of 500 units/kg/min during 10 to 20 min resulted in reperfusion of the distal coronary artery (group B = Thrombolysis). In the remaining five patients, IC thrombolysis was not successfully performed (group C = No effect). The degree of coronary artery stenosis immediately after reperfusion was 88.7 +/- 18.8% in group B. Long-term follow-up (four weeks) coronary angiography in groups A and B revealed improved patency to 79.2 +/- 19.3% and 79.4 +/- 27.8%, respectively. By contrast, total occlusion remained in group C. The ejection fraction measured four weeks later was slightly greater in group B than in group C, and was significantly greater in group A than in group C. If the average ages and complications of the other coronary vessels were considered, a significant difference was recognized among these three groups. The amplitude of the anterior wall motion of the patients with anterior infarction in each group assessed by a point score system was significantly increased in groups A and B as compared to group C. Peak CPK, GOT and LDH rose rapidly immediately after reperfusion and the time interval from the onset of symptoms to peak enzyme production was significantly shortened after reperfusion. These data supported the following concept: 1) coronary thrombus formation frequently occurs in acute myocardial infarction and can be rapidly lysed by IC infusion of UK with a total dose of 250,000 to 600,000 units, 2) reperfusion by lysis of IC thrombi in patients with acute myocardial infarction improves left ventricular wall motion, 3) peak enzyme rises rapidly after reperfusion, 4) the time interval from the onset of symptoms to peak enzyme production is remarkably shortened after repeat perfusion and that 5) no fatal arrhythmia nor bleeding are recognized. Thus, IC infusion of UK in the early stage of acute myocardial infarction was effective and useful.