Myocardial salvage with early anistreplase treatment.

This randomized, double-blind trial in 311 patients with acute myocardial infarction has shown that very early therapy with anistreplase outside the hospital is not only feasible, but provides a major survival advantage. The difference in the median delay to treatment between the group treated in the hospital and those treated earlier was 2 1/4 h. After 30 months, mortality in the early group was less than half that in the later group, so that every hour of delay beyond 2 h resulted in almost 7 additional deaths per 100 patients treated. This is a greater percentage loss of life than would have resulted from a similar delay in the provision of resuscitation for the prehospital cardiac arrest. Multivariate analysis showed that age, treatment delay, and time of presentation were significant risk factors, with patients presenting at 1 h having more than twice the mortality of those presenting at 4 h; the sicker the patient, the earlier the presentation. By 5 years, prehospital administration of anistreplase, by saving 2 h, resulted in an additional 57% of a year's survival per patient. This compares favorably with the projected 14% of a year survival per patient reported with TPA versus streptokinase in GUSTO. Prehospital therapy with anistreplase was highly cost effective when compared with streptokinase given in hospital, and the marginal cost-effectiveness ratio was much lower than that for TPA versus streptokinase derived from GUSTO.