Comparison of two dose regimens of intravenous tissue plasminogen activator for acute myocardial infarction.
Two dosing schedules of intravenous tissue plasminogen activator (t-PA) for acute myocardial infarction were compared in a multicenter trial. At 2.95 +/- 1.1 hours from onset of chest pain, 386 patients received 150 mg of intravenous t-PA. For the first 178 patients (group A), 60 mg were given in the first-hour dose and the remaining 90 mg were infused over 7 hours. In the subsequent 208 patients (group B), the first-hour dose was 1.0 mg/kg and the remaining 150 mg were given over 5 hours. At initial angiography 94 +/- 30 minutes into therapy, the infarct vessel patency was 64% in group A versus 75% in group B (p = 0.02). By final angiography with up to 4 selective contrast injections, patency was 68% versus 77%, respectively (p = 0.06). Repeat angiography at 7 to 10 days demonstrated reocclusion in 17% of group A and 13% of group B patients (p = 0.35). There was no difference in fibrinogen nadir or mean hematocrit drop between the 2 groups: 120 mg/dl and 11 points, respectively, in group A compared with 120 mg/dl and 10 points in group B. However, bleeding was reduced in group B patients as evident by a decrease in requirement for greater than or equal to 2 units of packed red blood cell transfusion (group A 36%, group B 27%, p = 0.05) and lower incidence of gastrointestinal bleeding (group A 12%, group B 4%, p = 0.002). To further study the importance of weight adjustment, patients were divided into 2 groups according to weight (less than or equal to 90 kg versus greater than 90 kg).(ABSTRACT TRUNCATED AT 250 WORDS)
Topol
E J
EJ
Department of Internal Medicine, University of Michigan, Ann Arbor.
George
B S
BS
Kereiakes
D J
DJ
Candela
R J
RJ
Abbottsmith
C W
CW
Stump
D C
DC
Boswick
J M
JM
Stack
R S
RS
Califf
R M
RM
D000800:Angioplasty, Balloon; D001777:Blood Coagulation / Q000187:drug effects; D001835:Body Weight; D002986:Clinical Trials as Topic; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000628:therapy; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use
D010959:Tissue Plasminogen Activator