Optimal dose for stroke thrombolysis in Asians: Low dose may have similar safety and efficacy as standard dose

Background: Although intravenous tissue-type plasminogen activator (t-PA) at a standard dose of 0.9mgkg^-1 is effective for patients with acute ischemic stroke, concerns have been raised regarding Asians. Objectives: To compare the safety and efficacy between low and standard doses for stroke thrombolysis. Patients/Methods: Consecutive patients receiving t-PA treatment were recruited according to the prespecified dosing policy from two medical centers in Taiwan: low dose (0.7mgkg^-1) at National Cheng Kung University Hospital (NCKUH) from August 2006 to June 2009, or standard dose (0.9mgkg^-1) at NCKUH from July 2009 to December 2010 and at Changhua Christian Hospital from May 2008 to December 2010. The primary safety outcome was the occurrence of symptomatic intracerebral hemorrhage (SICH). The secondary efficacy outcome was the proportion of patients with a modified Rankin Scale (mRS) grade of ≤1 at 3 months. Results: From August 2006 to December 2010, 261 patients were recruited, of whom 105 and 156 received low and standard doses, respectively. The occurrence of SICH was non-significantly lower in the standard-dose group than in the low-dose group (2.6% vs. 4.8%, respectively; P=0.34). The favorable outcome of mRS grade of ≤1 at 3 months was similar (38.4% and 41.1%, respectively; P=0.676). A review of other case series of low vs. standard doses in Asians also showed similar safety and efficacy. Conclusion: Our study, as well as other case series on Asians, revealed that standard-dose thrombolysis for acute ischemic stroke in an Asian population carries no increased risk of symptomatic intracerebral hemorrhage when compared with the low dose.