Reperfusion, patency and reocclusion with anistreplase (APSAC) in acute myocardial infarction.

Because the reestablishment of coronary blood flow is believed to be central to the benefit of thrombolytic therapy, measurements of reperfusion (i.e., angiography before and after therapy), patency (i.e., angiography after therapy) and reocclusion rates are important to the evaluation of new thrombolytic therapies. For anisoylated plasminogen streptokinase activator complex (APSAC, anistreplase), comparisons have been made with control or placebo therapies to assess absolute efficacy, and with streptokinase to assess relative efficacy. In pooled experience from reperfusion studies, APSAC (30 U over 2 to 5 minutes) led to angiographic reperfusion in 55% of patients (98 of 177) who had symptoms of acute myocardial infarction (MI) for less than 6 hours. Among 107 patients treated with APSAC in angiographic patency studies, 69% (74) showed an open infarct-related artery 1 to 4 hours after therapy. (Patency rates are generally 10 to 20% greater than reperfusion rates, because some patients with acute MI may have a patent [subtotally occluded or spontaneously reperfused] infarct-related artery when entered into patency studies.) Using early peaking (less than or equal to 15 hours) of the creatine kinase curve as an indicator, a patency rate of 63% was observed among 387 patients treated with APSAC. The initial success rate with thrombolytic therapies is diminished by the rates of reocclusion and reinfarction, which must be accounted for in determining the net success of therapy. In 6 studies, a total of 87 patients with initially patent arteries after APSAC returned for reevaluation in 1 to 3 days.(ABSTRACT TRUNCATED AT 250 WORDS)