INtra-arterial AltEplase folloWing successfuL reperfusIoN After mEchanical Thrombectomy

Prior treatment

• Contraindication to recombinant human tissue plasminogen activator (rt-PA) (except time to therapy).
• Recent intracranial surgery in the past 30 days.
• Stent placement and other situations during the EVT procedure that requires antiplatelet therapy or anti coagulation within the first 24 hours.

Other illness

• mRS score ≥ 2 before stroke onset
• Anticipated advanced comorbid disease with life expectancy \< 12 months
• Severe hypertension with SBP \> 185 mmHg or DBP \> 110 mmHg and refractory to treatment.
• Any active or recent major bleeding (gastrointestinal, urinary tract bleeding, etc.) in the last 30 days.
• Women who are pregnant at stroke onset.
• Known genetic or acquired bleeding disposition with anticoagulation factor deficiency.
• Severe allergy to contrast (non-mild rash allergy) or absolute contraindication to iodine contrast, heparin.
• Acute ischemic stroke with significant mass effect or evidence of midline shift on baseline neuroimaging, or clinical signs of brain herniation
• Suspected acute ischemic stroke involving multiple vascular territories or occlusion of two or more distinct vascular systems on neuroimaging
• Evidence of intracranial hemorrhage (including hemorrhagic transformation) on neuroimaging
• Any condition that, in the judgment of the investigator, makes the patient unsuitable for this study or where this study may impose a significant risk to the patient (e.g., inability to understand and/or comply with study procedures and/or follow-up due to psychiatric disorders, cognitive or emotional impairment).

Lab values

• Coagulation disorder with INR \> 1.7 or use of new oral anticoagulants (within 48 hours of symptom onset).
• Platelet count \< 50 G/L.
• Blood glucose \< 2,8 mmol/L (50 mg/dl) or \> 22,2 mmol/L (400 mg/dl)
• Known severe renal insufficiency with glomerular filtration rate \< 30 ml/min or blood creatinine \> 220 µmol/L (2,5 mg/dl).

Other

• Acute head trauma
• Requiring hemodialysis or peritoneal dialysis
• Suspected vascular occlusion as a result of infective endocarditis
• Suspected cerebral vasculitis based on medical history and/or angiographic evaluation.
• Suspected aortic dissection
• Brain tumor (with significant mass effect)
• Extracranial segment occlusion of the ICA and post-procedural etiology suggests vascular dissection.
• Intravenous heparin administration (however, heparinised saline flushes are allowed)
• Procedure time \> 90 min
• Number of thrombectomy passes \> 5
• Complications occur during EVT: Vascular rupture, dissection, or contrast extravasation
• Complete clinical recovery after rapid recanalization.
• Participation in other interventional randomized clinical trials that may confound the outcome assessment of the study.
• Unlikely to be available for 90-day follow-up

• Age ≥ 18 years old.
• No significant pre-stroke functional disability (pre-stroke mRS 0-1)
• Clinical diagnosis of acute ischemic stroke with anterior LVO
• Time from symptom onset to randomization within 24 hours, including wake-up stroke or unwitness stroke; the onset time refers to "Last Known Well" (LKW).
• Baseline NIHSS of 6 - 25
• Non-contrast CT (NCCT) or diffusion-weighted imaging (DWI)-MRI Alberta Stroke Program Early CT Score (ASPECTS) ≥ 6. For patients with available perfusion imaging (CTP/MRP), additional criteria include: Ischemic core volume ≤ 70mL; Mismatch volume ≥ 15 ml; Mismatch ratio ≥ 1.8
• Evidence of oclussion of the intracranial segment of the internal carotid artery (ICA), or M1 or M2 segment of the middle cerebral artery (MCA) on CT angiography (CTA) or MR angiography (MRA)
• Treated with EVT resulting eTICI score of 2b-3. Patients with an eTICI score of 2b-3 on the diagnostic cerebral angiography before MT are also eligible for the study.
• Informed consent obtained from patient or acceptable patient surrogate.