Effect of the Initial Bolus Volume of Recombinant Tissue-Type Plasminogen Activator on Coronary Recanalization and Infarct Size in Japanese Acute Myocardial Infarction Patients.

Coronary recanalization rate and infarct size were compared between 2 different methods of intravenously administering recombinant tissue-type plasminogen activator(rt-PA)41.4mg; 1)an initial bolus dose of 30% followed by infusion of the remainder over 60 min(30% group), and an initial bolus dose of 10% followed by infusion of the remainder over 60 min(10% group). Thirty min after beginning rt-PA infusion, the coronary recanalization rate was higher in the 30% group than in the 10% group(82.9%(34/41)vs 53.7%(22/41), p<0.01). The peak creatine kinase and peak creatine kinase-MB levels were lower in the 30% group than in the 10% group. We conclude that a higher initial boulus dose of rt-PA gives a higher rate of recanalizaiton of the infarct-related artery at the very early phase, and probably leads to a smaller infarct size.