Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomized Controlled Trial of Intra-arterial Reperfusion Therapy After Standard Dose Intravenous t-PA Within 4.5 Hours of Stroke Onset Utilizing Dual Target Imaging Selection.
Brief Summary: Patients presenting to the emergency department with acute ischaemic stroke, who are eligible for standard intravenous tPA therapy within 4.5 hours of stroke onset will be assessed for "dual target" major vessel occlusion and mismatch to determine their eligibility for randomisation into the trial. If the patient gives informed consent they will be randomised 50:50 using central computerised allocation to intra-arterial clot retrieval after IV tPA or IV tPA alone. The trial is prospective, randomised, open-label, blinded endpoint (PROBE) design.


Options:
A: Clinical Inclusion Criteria:

1. Signs \& symptoms consistent w/ the diagnosis of acute anterior circulation ischemic stroke
2. Age 18-90 years
3. Baseline NIHSSS is ≥ 6 and remains ≥6 immediately prior to randomization
4. Endovascular treatment can be initiated (femoral puncture) between 6 and 16 hours of stroke onset. Stroke onset is defined as the time the patient was last known to be at their neurologic baseline (wake-up strokes are eligible if they meet the above time limits).
5. modified Rankin Scale less than or equal to 2 prior to qualifying stroke (functionally independent for all ADLs)
6. Patient/Legally Authorized Representative has signed the Informed Consent form.

Clinical Exclusion Criteria:

1. Other serious, advanced, or terminal illness (investigator judgment) or life expectancy is less than 6 months.
2. Pre-existing medical, neurological or psychiatric disease that would confound the neurological or functional evaluations
3. Pregnant
4. Unable to undergo a contrast brain perfusion scan with either MRI or CT
5. Known allergy to iodine that precludes an endovascular procedure
6. Treated with tPA \>4.5 hours after time last known well
7. Treated with tPA 3-4.5 hours after last known well AND any of the following; age \>80, current anticoagulant use, history of diabetes or prior stroke, NIHSS \>25
8. Known hereditary or acquired hemorrhagic diathesis, coagulation factor deficiency; recent oral anticoagulant therapy with INR \> 3 (recent use of one of the new oral anticoagulants is not an exclusion if estimated GFR \> 30 ml/min).
9. Seizures at stroke onset if it precludes obtaining an accurate baseline NIHSS
10. Baseline blood glucose of \<50mg/dL (2.78 mmol) or \>400mg/dL (22.20 mmol)
11. Baseline platelet count \< 50,000/uL
12. Severe, sustained hypertension (Systolic BP \>185 mmHg or Diastolic BP \>110 mmHg)
13. Current participation in another investigational drug or device study
14. Presumed septic embolus; suspicion of bacterial endocarditis
15. Clot retrieval attempted using a neurothrombectomy device prior to 6 hrs from symptom onset
16. Any other condition that, in the opinion of the investigator, precludes an endovascular procedure or poses a significant hazard to the subject if an endovascular procedure was performed.

Neuroimaging Inclusion Criteria:

1. ICA or MCA-M1 occlusion (carotid occlusions can be cervical or intracranial; with or without tandem MCA lesions) by MRA or CTA

   AND
2. Target Mismatch Profile on CT perfusion or MRI (ischemic core volume is \< 70 ml, mismatch ratio is \>/= 1.8 and mismatch volume\* is \>/= 15 ml)

Alternative neuroimaging inclusion criteria (if perfusion imaging or CTA/MRA is technically inadequate):

A) If CTA (or MRA) is technically inadequate:

Tmax\>6s perfusion deficit consistent with an ICA or MCA-M1 occlusion AND Target Mismatch Profile (ischemic core volume is \< 70 ml, mismatch ratio is \>1.8 and mismatch volume is \>15 ml as determined by RAPID software)

B) If MRP is technically inadequate:

ICA or MCA-M1 occlusion (carotid occlusions can be cervical or intracranial; with or without tandem MCA lesions) by MRA (or CTA, if MRA is technically inadequate and a CTA was performed within 60 minutes prior to the MRI) AND DWI lesion volume \< 25 ml

C) If CTP is technically inadequate:

Patient can be screened with MRI and randomized if neuroimaging criteria are met.

Neuroimaging Exclusion Criteria:

1. ASPECTS score \<6 on non-contrast CT (if patient is enrolled based on CT perfusion criteria)
2. Evidence of intracranial tumor (except small meningioma) acute intracranial hemorrhage, neoplasm, or arteriovenous malformation
3. Significant mass effect with midline shift
4. Evidence of internal carotid artery dissection that is flow limiting or aortic dissection
5. Intracranial stent implanted in the same vascular territory that precludes the safe deployment/removal of the neurothrombectomy device
6. Acute symptomatic arterial occlusions in more than one vascular territory confirmed on CTA/MRA (e.g., bilateral MCA occlusions, or an MCA and a basilar artery occlusion).
B: Inclusion Criteria:

* New focal disabling neurologic deficit consistent with acute cerebral ischemia (NIHSS \>/= 6)
* Age \>/= 18 ≤ 85
* Clot retrieval procedure can be initiated within 8 hours from onset
* Large vessel proximal anterior circulation occlusion on MR or CT angiography (internal carotid, M1 or M2 MCA)
* Pretreatment MRI performed according to MR RESCUE protocol
* Signed informed consent obtained from the patient or patient's legally authorized representative
* Premorbid modified Rankin score of 0-2
* Allowed but not required: patients treated with IV tPA (tissue plasminogen activator) up to 4.5 hours from symptom onset with persistent target occlusion on post-treatment MR RESCUE MR or CT protocol performed at the completion of drug infusion (Note: Rapidly improving neurological signs prior to randomization is an exclusion)

Exclusion Criteria:

* NIHSS \>/= 30
* Contraindication to MRI (pacemaker etc)
* Acute intracranial hemorrhage
* Coma
* Rapidly improving neurological signs prior to randomization
* Pre-existing medical, neurological or psychiatric disease that would confound the neurological, functional, or imaging evaluations
* Pregnancy
* Known allergy to iodine previously refractory to pretreatment medications
* Current participation in another experimental treatment protocol
* Contrast-Enhanced Neck MRA (magnetic resonance angiography) or CTA (computed tomography angiography) suggests proximal ICA occlusion, proximal carotid stenosis \> 67%, or dissection
* INR \> 3.0 (international normalized ratio)
* PTT \> 3 x Normal (partial thromboplastin time)
* Imaging data cannot be processed by the MR RESCUE computer
* Renal Failure (serum creatinine \> 2.0 or Glomerular Filtration Rate \[GFR\] \< 30)

MRI Exclusion Criteria:

* Contraindication to MRI (pacemaker, etc)

CT Exclusion Criteria:

* Contraindication to iodinated contrast\*\*

  \*\*Examples of possible iodinated contrast contraindications include:
* Hyperthyroidism
* History of severe allergic reaction to iodinated contrast material
* History of sever kidney disease as an adult, including tumor or transplant surgery, or family history of kidney failure
* Paraproteinemia syndromes or multiple myeloma
* Collagen vascular disease
* Severe cardiac insufficiency
* Severely compromised liver function
* Current therapy with metformin, aminoglycosides
C: Inclusion Criteria:

1. 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

   Dual target:
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 Criteria:

1. 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
D: Inclusion Criteria:

* 1. Acute ischemic stroke where patient is ineligible for IV thrombolytic treatment or the treatment is contraindicated (e.g., subject presents beyond recommended time from symptom onset), or where patient has received IV thrombolytic therapy without recanalization after a minimum of 30 min from start of iv tPA infusion
* 2. No significant pre-stroke functional disability (mRS ≤ 1)
* 3. Baseline NIHSS score obtained prior to randomization must be equal or higher than 6 points
* 4. Age ≥18 and ≤ 85.
* 5. Occlusion (TICI 0-1) of the intracranial ICA (distal ICA or T occlusions), MCA-M1 segment or tandem proximal ICA/MCA-M1 suitable for endovascular treatment, as evidenced by CTA, MRA or angiogram, with or without concomitant cervical carotid occlusion or stenosis
* 6. Patient treatable within eight hours of symptom onset. Symptoms onset is defined as point in time the patient was last seen well (at baseline). Treatment start is defined as groin puncture.
* 7. Informed consent obtained from patient or acceptable patient surrogate

Exclusion Criteria:

* Clinical criteria
* 1. Known hemorrhagic diathesis, coagulation factor deficiency, or oral anticoagulant therapy with INR \> 3.0
* 2. Baseline platelet count \< 30.000/µL
* 3. Baseline blood glucose of \< 50mg/dL or \>400mg/dl
* 4. Severe, sustained hypertension (SBP \> 185 mm Hg or DBP \> 110 mm Hg)
* 5. Patients in coma (NIHSS item of consciousness \>1) (Intubated patients for transfer could be randomized only in case an NIHSS is obtained by a neurologist prior transportation).
* 6. Seizures at stroke onset which would preclude obtaining a baseline NIHSS
* 7. Serious, advanced, or terminal illness with anticipated life expectancy of less than one year.
* 8. History of life threatening allergy (more than rash) to contrast medium
* 9. Subjects who has received iv t-PA treatment beyond 4,5 hours from the beginning of the symptoms
* 10. Renal insufficiency with creatinine ≥ 3 mg/dl
* 11. Woman of childbearing potential who is known to be pregnant or lactating or who has a positive pregnancy test on admission.
* 12. Subject participating in a study involving an investigational drug or device that would impact this study.
* 13. Cerebral vasculitis
* 14. Patients with a pre-existing neurological or psychiatric disease that would confound the neurological or functional evaluations, mRS score at baseline must be ≤ 1. This excludes patients who are severely demented, require constant assistance in a nursing home type setting or who live at home but are not fully independent in activities of daily living (toileting, dressing, eating, cooking and preparing meals, etc.)
* 15. Unlikely to be available for 90-day follow-up (e.g. no fixed home address, visitor from overseas).

Neuroimaging criteria:

* 16. Hypodensity on CT or restricted diffusion amounting to an ASPECTS score of \<7 on NCCT or \<6 on DWI MRI. Patients 81 to 85 years old with ASPECTS score on non-contrast CT or DWI MRI \<9 must be excluded. ASPECTS must be evaluated by CBV maps of CT Perfusion, CTA source imaging (CTA-SI) or DWI-MR in patients whose vascular occlusion study (CTA/MRA) confirming qualifying occlusion, is performed beyond 4.5 hours of last seen well.
* 17. CT or MR evidence of hemorrhage (the presence of microbleeds is allowed).
* 18. Significant mass effect with midline shift.
* 19. Evidence of ipsilateral carotid occlusion, high grade stenosis or arterial dissection in the extracranial or petrous segment of the internal carotid artery that cannot be treated or will prevent access to the intracranial clot or excessive tortuosity of cervical vessels precluding device delivery/deployment
* 20. Subjects with occlusions in multiple vascular territories (e.g., bilateral anterior circulation, or anterior/posterior circulation)
* 21. Evidence of intracranial tumor (except small meningioma).

Answer: C