Low- versus Standard-Dose Intravenous Alteplase in the Context of Bridging Therapy for Acute Ischemic Stroke: A Korean ENCHANTED Study

BACKGROUND AND PURPOSE Following the positive results from recent trials on endovascular therapy (EVT), bridging therapy (intravenous alteplase plus EVT) is increasingly being used for the treatment of acute ischemic stroke. However, the optimal dose of intravenous alteplase remains unknown in centers where bridging therapy is actively performed. The optimal dose for eventual recanalization and positive clinical outcomes in patients receiving bridging therapy also remains unknown. METHODS In this prospective Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED) sub-study, we explored the outcomes following treatment with two different doses (low- [0.6 mg/kg] or standard-dose [0.9 mg/kg]) of intravenous alteplase across 12 Korean centers where EVT is actively performed. The primary endpoint was a favorable outcome at 90 days (modified Rankin Scale scores 0 to 1). Secondary endpoints included symptomatic intracerebral hemorrhage (ICH) in all patients, and the recanalization rate and favorable outcome in patients who underwent cerebral angiography for EVT (ClinicalTrials.gov, number NCT01422616). RESULTS Of 351 patients, the primary outcome occurred in 46% of patients in both the standard-(80/173) and low-dose (81/178) groups (odds ratio [OR], 1.14; 95% confidence interval [CI], 0.72 to 1.81; P=0.582), although ICHs tended to occur more frequently in the standard-dose group (8% vs. 3%, P=0.056). Of the 67 patients who underwent cerebral angiography, there was no significant difference in favorable functional outcome between the standard- and low-dose groups (39% vs. 21%; OR, 2.39; 95% CI, 0.73 to 7.78; P=0.149). CONCLUSIONS There was no difference in functional outcome between the patients receiving different doses of alteplase in centers actively performing bridging therapy.