Randomized comparison of coronary thrombolysis achieved with double-bolus reteplase (Recombinant plasminogen activator) and front-loaded, accelerated alteplase (Recombinant tissue plasminogen activator) in patients with acute myocardial infarction

Background The therapeutic benefit of thrombolytic therapy has been shown to correlate directly with completeness (TIMI grade 3 flow) and speed of reperfusion of the infarct-related coronary artery. The purpose of the RAPID II study was to determine whether a double-bolus regimen of reteplase, a recently developed deletion mutant of wild-type tissue plasminogen activator, could improve 90-minute coronary artery patency rates achieved with the most successful standard regimen, an ''accelerated'' front-loaded infusion of alteplase. Methods and Results Three hundred twenty-four patients with acute myocardial infarction were randomized to receive (along with intravenous heparin and aspirin) either a 10 plus 10 megaunits double bolus of reteplase or front-loaded alteplase. The primary end point of ''patency at 90 minutes, graded according to the TIMI classification'' was centrally assessed in a blinded fashion. Infarct-related coronary artery patency (TIMI grade 2 or 3) and complete patency (TIMI grade 3) at 90 minutes after the start of thrombolytic therapy were significantly higher in the reteplase-treated patients (TIMI grade 2 or 3: 83.4% versus 73.3% for front-loaded alteplase-treated patients, P=.03; TIMI grade 3: 59.9% versus 45.2%, P=.01). At 60 minutes, the incidence of both, patency and complete patency, was also significantly higher in reteplase-treated patients (reteplase versus alteplase, TIMI grade 2 or 3: 81.8% versus 66.1%, P=.01; TIMI grade 3: 51.2% versus 37.4%, P<.03). Reteplase-treated patients required fewer acute additional coronary interventions (13.6% versus 26.5%, P<.01); and 35-day mortality was 4.1% for reteplase and 8.4% for alteplase (P=NS). There were no significant differences between reteplase and alteplase in bleedings requiring a transfusion (12.4% versus 9.7%) or hemorrhagic stroke (1.2% versus 1.9%). Conclusions Reteplase, when given as a double bolus of 10 plus 10 megaunits to patients with acute myocardial infarction, achieves significantly higher rates of early reperfusion of the infarct-related coronary artery and requires significantly fewer acute coronary interventions than front-loaded alteplase without an apparent increased risk of complications.