Current literature has only limited information on the natural history of acute ischemic stroke from large vessel occlusion in a stroke cohort who presents within 8 hours from symptom onset, particularly on 90 day functional outcome as defined by the mRS. Data from this trial will advance our knowledge on this important topic and may serve as a bench mark for future trials

Inclusion Criteria:

• From 18 to 85 years of age.
• Evidence of proximal anterior circulation large vessel occlusion (TIMI 0-1)(TICI 0-1) from CT Angiography. Target vessel occlusion may include the anterior circulation.
• Presented with symptoms consistent with acute ischemic stroke within 8 hours of symptom onset. Patients who presented within 3 hours must be ineligible or refractory to IV rtPA therapy.
• At time of enrollment, neurological deficit resulting in an NIH Stroke Scale (NIHSS) score greater than 10
• Known core infarct volume assessed by CTP, CTA or DWI scans

Exclusion Criteria:

• History of stroke in the past 3 months.

• Pre-existing neurological or psychiatric disease that could confound the study results such as a pre-stroke mRS score greater than 1

• Known severe allergy to contrast media

• Uncontrolled hypertension (defined as systolic blood pressure greater than 185 mmHg or diastolic blood pressure less than 110 mmHg)

• CT evidence of the following conditions before enrollment:

  • Significant mass effect with midline shift
  • Evidence of intracranial hemorrhage

• Treated with endovascular therapy for acute stroke

• Life expectancy less than 90 days

• Participation in another clinical investigation that could confound the evaluation of the study

Patients presenting with symptoms of acute ischemic stroke within 8 hours from symptom onset and with an imaging-defined large cerebral vessel occlusion and a known infarct volume will be enrolled and followed for 90-days.