The goal of this clinical trial is to evaluate the efficacy and safety of tenecteplase administered 4.5-9 hours after stroke onset (defined as the time the patient was first found with symptoms, including wake-up stroke and unwitnessed stroke) in patients with acute ischemic stroke (AIS) guided by DWI-FLAIR mismatch on MRI. The main questions it aims to answer are:
1. Does tenecteplase improve functional outcomes at 90 days compared with standard treatments in AIS patients administered 4.5-9 hours after stroke onset guided by DWI-FLAIR mismatch? 2. The safety of tenecteplase thrombolysis for AIS patients in the 4.5-9 hours guided by DWI-FLAIR mismatch.
Researchers will compare tenecteplase to placebo to see if it is effective and safe for these patients.
Participants will be randomly assigned (1:1) immediately after randomization:
* Tenecteplase group: received tenecteplase, intravenously as a bolus administered over a period of 5 to 10 seconds at a dose of 0.25 mg per kilogram (maximum dose, 25 mg), plus aspirin placebo (300 mg). * Control group: aspirin (300 mg) plus tenecteplase placebo. From day 2 to day 90, all patients will be conformed to the 2023 Chinese Guidelines for Diagnosis and Treatment of Acute Ischemic Stroke.
Age ≥ 18 years;
AIS with symptom onset 4.5-9 hours before enrollment, including wake-up stroke and unwitnessed stroke (onset time defined as when symptoms were first noticed);
DWI-FLAIR mismatch: visible lesion on DWI with no marked visible lesion on FLAIR;
DWI infarct core not exceeding one-third of the middle cerebral artery territory, one-half of the anterior cerebral artery territory, or one-half of the posterior cerebral artery territory;
Planned endovascular treatment;
Contradictory to MRI examination;
MRI image not qualified for evaluation;
Serious neurological deficits before onset (mRS≥2);