[The evolution of hospital mortality due to acute myocardial infarct in the first 2 GISSI studies. Participants in the GISSI 1 and GISSI 2 studies. Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto Miocardico].

During the short while of 5 years, between 1984 and 1985, two large clinical trials have been performed in Italy concerning fibrinolytic therapy in Acute Myocardial Infarction: GISSI 1 and GISSI 2. They made possible to evaluate the evolution of demographic and clinical features, the in-hospital mortality rate, and the causes of death of a huge number of patients admitted to CCU throughout the whole country. Out of 31,826 patients with acute myocardial infarction admitted to 176 CCU participating to the GISSI 1 16.9% were 75 years old and 24.7% were females; 21.8% and 26.4% were the percentages in the 38,086 patients admitted to the 223 CCU participating in the GISSI 2. Despite the higher prevalence of the two demographic characteristic with the worse prognosis, the in-hospital mortality rates were respectively 12.2% in the GISSI 1 and 10.0% in the GISSI 2 studies, with a statistically significant decrease (RR 0.84; C.L. 0.80-0.88). The significant decrease in the in-hospital mortality concerns also the patients populations selected according to the same criteria of inclusion in the two trials (within 6 hours from the onset of symptoms and with only ST elevation at the ECG of admission) and to the treatment with fibrinolytic drug (SK or rtPA). As a matter of fact 468 patients died of the 4,696 (10.0%) treated with SK in the GISSI 1 against 1,092 patients of 12,381 (8.8%) enrolled in the GISSI 2 and treated with SK or rtPA (RR 0.87; L.C. 0.78-0.98). The reduction of in-hospital mortality may be explained by some differences in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)