To determine whether the extent of the ischemic penumbra apparent on perfusion-diffusion MRI can be used to identify patients who would respond positively and safely to tissue plasminogen activator (tPA) beyond 3 hours post-stroke.
- Tissue plasminogen activator (Activase®)Drug
Intervention Desc: Thrombolytic
Double-blind, randomized, controlled pilot study.
Eligible patients will have baseline MRI studies with gadolinium contrast, including DWI, perfusion-weighted imaging (PWI), and magnetic resonance angiography (MRA). All participants will be randomized into tPA or placebo groups within 3-6 hours after stroke onset. tPA for all patients will be dosed at 0.9 mg/kg, with a maximum dose of 90 mg, and will be delivered with 10% injected in a 1-minute bolus, and the remainder infused over 60 minutes. Placebo infusions will be delivered in an identical manner. Patients will be observed every 15 minutes for 2 hours, every hour for 4 hours, every 2 hours for 12 hours, and every 4 hours until reviewed by an investigator. All patients will receive repeat MRI studies (DWI, PWI, MRA) at 3-5 days, and at 90 days post-stroke.
|Type||Measure||Time Frame||Safety Issue|
|Primary||Change in the size of the ischemic lesion between baseline and follow-up studies, as visualized with diffusion-weighted imaging (DWI).|
|Secondary||Reperfusion defined as change between acute PWI volume(3-6 hours) and subacute PWI volume (3-5 days); symptomatic hemorrhagic transformation at day 3, as assessed by MRI; infarct volume, as measured with T2-weighted MRI; degree of recanalization of the MCA; proportion of patients making an 11-point improvement in their NIHSS score; percentage of patients reaching an MRS score of 0 - 2 or a Barthel Index (BI) score >= 85.|