The Effect Of Low-dose Thrombolysis Followed By Back-up Tracoronary Stent Implanting For Acute Myocardial Infarction

Objective The aim of this study was to elucidate the efficacy and safety of the injection of a low-dose recombinant tissue-type plasminogen activator(rt-PA), followed by back-up in tracoronary stent implanting in patients with acute myocardial infarction(AMI). Methods The 112 patients with AMI who were admitted to hospital within 6 hours of onset of symptoms were randomly assigned to a treatment with 50 mg bolus rt-PA group(group T, n=56) and no rt-PA group(group P, n=56), followed by back-up intracoronary stent implanting. The results of angiography, success rate of intracoronary stent implanting, left ventricular end-diastolic volume and left ventricular ejection were compared in two groups.Results There were no significant difference between the two groups in the sex, the age, the frequency of pre-infarction angina and the times from onset of myocardial infarction to coronary angiography. The coronary angiographies showed that the blood flow of coronary reaching TIMI grade HI was significantly higher in group T than in group P ( 61.2% vs 12.6% p<0.05). The success rate of intracoronary stent implanting was 100% in group T, while 96.9% in group P. The left ventricular ejection after 3 months was significantly higher in group T than in group P (59.2% ± 11.2% vs 50.6% ± 10.9%, p<0.05). The bleeding comlications were of no significant vaviation. Conclusion These findings explain the treatment with 50 mg bolus rt-PA followed by back-up in tracoronary stent implanting is effective for the early reperfusion and preservation of left ventricular function, without increasing of bleeding complications in patients with AMI.