In this multicenter , randomized , open-label trial , 461 patients with acute myocardial infarction received 100 mg alteplase as a front-loaded 90-minute infusion ( 15 mg bolus , then 50 mg over a 30-minute period , then 35 mg over a 60-minute period ) or double bolus ( two 50 mg bolus injections 30 minutes apart ) .
