Recombinant tissue plasminogen activator (rt-PA) is the most promising agent use for salvaging ischemic myocardium in acute infarction. To assess the safety and efficacy of rt-PA thrombolytic therapy, an open label clinical trial was conducted. Patients of acute myocardial infarction with angina, occurring within the five previous hours, was treated with rt-PA 100 mg infusion within three hours; followed with coronary arteriography to assess the patency rate of infarct vessels. Twenty-five cases of acute myocardial infarction were studied over a 10-month period. The patients, 24 male and one female, were aged 58.1 +/- 7.7 years. Rt-PA was given at 3.17 +/- 1.0 hour. Infarct-related vessels had opened in 21/24 cases when examined with coronary arteriogram three hours after infusion. Good antegrade flow of grade 2 to 3 was gained in 20/24 cases, representing an 83% success rate. One patient expired from cardiogenic shock during the infusion; another was expired from noncardiac accident after coronary bypass graft. The total inhospital mortality rate was about 8%. There was no major bleeding complication except in one case with gastrointestinal bleeding requiring transfusion.
In conclusion: rt-PA is safe and effective in the treatment of acute myocardial infarction in the early stage. Coronary arteriography can be safely delayed until three hours postinfusion, and the achieved reperfusion rate is up to 83%.