Direct Transfer to an Endovascular Center Compared to Transfer to the Closest Stroke Center in Acute Stroke Patients With Suspected Large Vessel Occlusion

To evaluate the hypothesis that direct transfer to an Endovascular Stroke Center, compared to transfer to the closest Local Stroke Center, offers a better outcome in the distribution of the modified Rankin Scale scores at 90 days in acute ischemic stroke patients with clinically suspected Large Vessel Occlusion identified by Emergency Medical Services (EMS).

Prospective, multicenter, cluster randomized controlled, usual care conditions, open, blinded-endpoint trial of acute stroke patients with suspected acute large vessel occlusion (LVO) identified by EMS at first assistance on the field, in which two strategies will be compared: transfer to the closest local stroke center (Local-SC) Vs. direct transfer to an endovascular stroke center (EVT-SC).

The RACE scale (Rapid Arterial oCclusion Evaluation) will be used as a prehospital screening tool to identify acute stroke patients with suspicion of LVO. Upon candidate identification, EMS will contact a stroke neurologist on call using a prehospital telestroke system who will confirm inclusion criteria and will allocate the subjects to a specific intervention according to a pre-established temporal sequence. Allocation will account for 3 strata: time band (two groups of 12 hours), territory (metropolitan versus provincial area) and week day (working versus weekend day).

Subjects will be followed up to 90 days post-randomization.

Eligibility Criteria:
Inclusion Criteria:

* Suspected LVO acute stroke patients identified by a RACE scale score \>4 at the pre-hospital setting, that is evaluated by EMS professionals when attending patients, in non-stroke ready centers or primary health centers, previous to the transfer to a stroke center.
* Patients located in geographical areas in which the reference stroke center is a hospital not capable to offer endovascular treatment (Primary stroke Center or Telestroke Center).
* Estimated arrival time at an EVT-SC \<7 hours from symptom onset. Symptom onset is defined as point in time the patient was last seen well (at baseline).
* No significant pre-stroke functional disability (modified Rankin scale 0 - 2)
* Age ≥18
* Deferred informed consent obtained from patient or acceptable patient surrogate (after the acute phase, as permission to use clinical data within a clinical registry)

Exclusion Criteria:

* Patients in a coma (NIHSS item of consciousness \>1)
* Patients with unstable clinical status who require emergent life support care
* Serious, advanced, or terminal illness with anticipated life expectancy of less than 6 month.
* Suspected LVO acute stroke patients identified at the Emergency Department of a stroke center
* Subject participating in a study involving an investigational drug or device that would impact this study.
* Patients with a pre-existing neurological or psychiatric disease that would confound the neurological or functional evaluations. 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.)
* Unlikely to be available for 90-day follow-up (e.g. no fixed home address, visitor from overseas).