An angiographic assessment of alteplase: double-bolus and front-loaded infusion regimens in myocardial infarction. DouBLE Study Investigators. Double Bolus Lysis Efficacy.
BACKGROUND
This study was designed to investigate the efficacy of alteplase double-bolus dosing compared with the front-loaded 90-minute infusion regimen in patients with acute myocardial infarction. Recent pilot studies have suggested that bolus dosing may provide improved efficacy in establishing early, complete, and sustained patency of the infarct-related artery in the thrombolytic treatment of acute myocardial infarction.


RESULTS
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). All patients also received intravenous heparin and oral aspirin during and after alteplase treatment. The 90-minute angiographic patency rates were 74.5% in the double-bolus group and 81.4% in the infusion group (p = 0.08). Patency rates were also comparable for the two groups at 60 minutes (76.8% vs 77.5%) and 24 hours (95.5% vs 93.5%) after initiation of treatment. In-hospital mortality rates were 4.5% in the bolus group and 1.3% in the infusion group (p = 0.04); 30-day mortality rates were 4.5% and 1.7%, respectively (p = NS). The two-groups were comparable in frequency of all other adverse events.


CONCLUSIONS
Double-bolus alteplase administration produced reperfusion rates comparable to front-loaded infusion, but in-hospital and 30-day mortality rates were higher in the double-bolus group. These findings are in agreement with those of the COBALT megatrial, which also reported a trend to higher mortality rates with double-bolus dosing.
Bleich
S D
SD
Cardiology Associates of Jefferson, East Jefferson General Hospital, Metairie, LA 70006, USA.
Adgey
A A
AA
McMechan
S R
SR
Love
T W
TW
D000368:Aged; D002170:Canada; D017023:Coronary Angiography; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D010960:Plasminogen Activators / Q000008:administration & dosage*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D016896:Treatment Outcome; D006113:United Kingdom; D014481:United States
D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator