Inclusion Criteria1. Patients presenting with anterior circulation acute ischaemic stroke eligible using standard criteria to receive IV tPA within 4.5 hours of stroke onset
2. Patient, family member or legally responsible person depending on local ethics requirements has given informed consent
3. Patient‟s age is ≥18 years
4. Intra-arterial clot retrieval treatment can commence (groin puncture) within 6 hours of stroke onset.
Imaging inclusion criteria
5. Arterial occlusion on CTA or MRA of the ICA, M1 or M2
6. Mismatch - Using CT or MRI with a Tmax >6 second delay perfusion volume and either CT-rCBF or DWI infarct core volume. a) Mismatch ratio of greater than 1.2, and b) Absolute mismatch volume of greater than 10 ml, and. c) Infarct core lesion volume of less than 70mL
Exclusion Criteria1. Intracranial haemorrhage (ICH) identified by CT or MRI
2. Rapidly improving symptoms at the discretion of the investigator
3. Pre-stroke mRS score of ≥ 2 (indicating previous disability)
4. Inability to access the cerebral vasculature in the opinion of the neurointerventional team
5. Contra indication to imaging with MR with contrast agents
6. Participation in any investigational study in the previous 30 days
7. Any terminal illness such that patient would not be expected to survive more than 1 year
8. Any condition that, in the judgment of the investigator could impose hazards to the patient if study therapy is initiated or affect the participation of the patient in the study.
9. Pregnant women
10. Previous stroke within last three months
11. Recent past history or clinical presentation of ICH, subarachnoid haemorrhage (SAH), arterio-venous (AV) malformation, aneurysm, or cerebral neoplasm. At the discretion of each Investigator.
12. Current use of oral anticoagulants and a prolonged prothrombin time (INR > 1.6)
13. Use of heparin, except for low dose subcutaneous heparin, in the previous 48 hours and a prolonged activated partial thromboplastin time exceeding the upper limit of the local laboratory normal range.
14. Use of glycoprotein IIb - IIIa inhibitors within the past 72 hours. Prior use of single or dual agent oral platelet inhibitors (clopidogrel and/or low-dose aspirin) is permitted.
15. Clinically significant hypoglycaemia.
16. Uncontrolled hypertension defined by a blood pressure > 185 mmHg systolic or >110 mmHg diastolic on at least 2 separate occasions at least 10 minutes apart, or requiring aggressive treatment to reduce the blood pressure to within these limits. The definition of "aggressive treatment" is left to the discretion of the responsible Investigator.
17. Hereditary or acquired haemorrhagic diathesis
18. Gastrointestinal or urinary bleeding within the preceding 21 days
19. Major surgery within the preceding 14 days which poses risk in the opinion of the investigator.
20. Exposure to a thrombolytic agent within the previous 72 hrs