Short- and Long-Term Comparative Study of Anistreplase Versus Streptokinase in Acute Myocardial Infarction

Streptokinase is well established as an effective thrombolytic. Anistreplase, a new thrombolytic drug, is a complex of streptokinase and acylated human plas minogen that can be administered by intravenous bolus and activates plasmino gen at the clot site. Although both streptokinase and anistreplase are effected in treating myocardial infarction (MI), they have different pharmacologic proper ties. This study was designed to identify short- and long-term differences in their clinical effectiveness, safety in use, and survival rates in patients with acute MI. One hundred ten successive patients under seventy years of age admitted within three hours after onset of sustained chest pain suggestive of acute MI were randomized to receive either 30 units of anistreplase intravenously over five minutes or intravenous injection of 750,000 units of streptokinase over thirty to sixty minutes. Reperfusion was achieved in 34 of the 52 (65%) patients treated with anis treplase and in 41 of the 58 (71%) patients treated with streptokinase (p = NS). The two drugs were equally effective in preserving left ventricular ejection frac tion, which was found to be significantly better in patients with anterior wall MI who had achieved reperfusion than it was in those who did not (p < 0.02). One-month, twelve-month, and thirty-six-month survival rates were high (96% to 88%) with no significant difference between the two treatment groups. The authors conclude that the two drugs are equally effective thrombolytic agents but that anistreplase has the advantage that it can be administered as a bolus injection.