EFFECTIVENESS OF INTRAVENOUS THROMBOLYTIC TREATMENT IN ACUTE MYOCARDIAL INFARCTION:SHORT AND MEDIUM TERM PROGNOSIS
An unblinded trial of intravenous stretokinase in early acute myocardial infarction was planned to study wheter the drug produces a clinically relevant benefit in terms of reduction of in-hospital and one year mortality.11806 pts in one hundred and seventy six coronary care units were enrolled over 17 months.Patients admitted within 12 h after o.nSet of symptons and with no contraindications to SK were randomized to receive SK in addition to usual treatment and complete data were obtained in 11712 for what concerns in hospital prognosis.At 21 days overall hospital mortality was 10.7% in SK recipients versus 13%,in controls,an 18% reduction(p=0.0002,relative risk 0.81).The extent of beneficial effect appears to be a function of time from onset of pain to SK infusion(relative risk 0.74,0.80, 0.87 and 1.19 for the 0-3,3-6,6-9 and 9-12 h subgroups).The data of 1-year follow-up concerning 11605 pts(95.3% of the whole population)were available up to December the 31st.1987.4333 pts out of the SK-treated group(74.0%)and 4219 out of the control one (72.1%)were alive,with a significant difference.These results document that the benefit produced by SK in the hospital period remains substantially unchanged.The differences in mortality in favour of SK vs.C remain highly significant specifically for the 0-3 and 3-6 hrs subgroups and is dramatic for patients treated between one hour from onset of symptoms. 503 out of the 637 treated with SK were alive at 1-year follow-up versus 443 out of 641 control group pts:the amplitude of the benefit seems to be further increased in this particular subgroup.The GISSI results document conclusively that an acute thrombolytic treatment with SK in AMI is effective in reducing mortality not only over the short,but also over the medium period.