Low vs standard dose of recombinant tissue plasminogen activator in treating East Asian patients with acute ischemic stroke

Background : Intravenous recombinant tissue plasminogen activator (rtPA) has been approved to treat eligible patients with acute ischemic stroke within 4.5 hours of onset. The rationale for using a lower dose in Asian patients came from concerns about intracerebral hemorrhage because of the racial differences in blood coagulation-fibrinolysis factors.
Aim : The aim of this systemic review was to compare the data from previous studies to address the efficacy and safety of using low-dose vs standard-dose rtPA in treating patients with acute ischemic stroke.
Material and Methods : Previous studies were searched and analyzed. The confidence interval was calculated at 95%. Baseline characteristics and outcomes of the patients were compared between two doses of rtPA (0.6 vs 0.9 mg/kg), using Z test for two independent proportions.
Results : Patients who received standard-dose rtPA had significantly higher favorable outcome at 3 months (33.1 vs 47.2%, P<0.0001), without significant difference in the rates of symptomatic intracerebral hemorrhage (3.5 vs 4.3%, P = 0.42) and mortality (13.1 vs 11.7%, P = 0.56). However, patients in the low-dose group were older and had more severe stroke.
Conclusions : Patients receiving standard-dose rtPA seem to have higher rates of favorable outcome. However, there were significant differences in baseline characteristics between the two groups. A further, well-designed, randomized study in the same population is still needed to clarify the suspected benefit of the standard dose for East Asian patients.