Neuroprotective Effect of Remote Ischemic Conditioning in Ischemic Stroke Treated With Mechanical Thrombectomy

Change in Neurological prognosis

Functional neurological prognosis assessed by: 1/ National Institutes of Health Stroke Scale (NIHSS) score on day 7 (NIHSS score for each ability is a number between 0 and 4 with 0 being normal functioning and 4 being completely impaired. The patient's NIHSS score is calculated by adding the number for each element of the scale; 42 is the highest score possible. The higher the score, the more impaired neurologically a stroke patient is) 2/ Modified Rankin Score (MRS) score at 90 days (score from 0 to 6 with 0 being normal functioning and 6 being death, the higher the score the more impaired neurologically a stroke patient is) and 3/ Incidence of early neurological worsening (Difference in NIHSS score between inclusion and day 1 \> 4 points).

Time frame: 1/ National Institutes of Health Stroke Scale (NIHSS) score will be evaluated at day 7; 2/ Modified Rankin Score (mRS) will be evaluated at day 90 and 3/ Incidence of early neurological worsening will be evaluated at inclusion and up to day 1.

Change in growth of the supposed irreversible lesion measured by Magnetic Resonance Imaging (MRI) from admission to day 1.

It will be expressed as a percentage of the size of the hypoperfused area measured on the admission Magnetic Resonance Imaging (MRI).

Time frame: Magnetic Resonance Imaging (MRI) will be performed at inclusion (Day 0) and on day 1.

Arterial reperfusion measured by the Thrombolysis in Cerebral Infarction (TICI) score at the end of the thrombectomy procedure.

The Thrombolysis in Cerebral Infarction (TICI) score is a tool for determining the response of thrombolytic therapy for ischemic stroke and is defined as follows: 0=no perfusion; 1= penetration, but no distal branch filling; 2a= perfusion with incomplete (\<50%) distal branch filling; 2b=perfusion with incomplete (\>50%) distal branch filling; and 3=full perfusion with filling of all distal branches. A score of 0 being the least favorable outcome for the patient (no perfusion) and a maximum score of 3 being the most favorable outcome for the patient (full perfusion).

Time frame: Day 1 of thrombectomy

Arterial reperfusion measured at Day 1 by Magnetic Resonance Imaging (MRI).

Arterial reperfusion according to the Arterial Occlusive Lesion (AOL) score. This score is related to recanalization of the primary arterial occlusive lesion on a scale of 0 to 3 : 0 is no recanalization of the primary occlusive lesion; 1 is incomplete or partial recanalization of the primary occlusive lesion with no distal flow; 2 is incomplete or partial recanalization of the primary lesion with any distal flow; and 3 is complete recanalization of the primary occlusive lesion with any distal flow. The most favorable outcome for the patient is a score of 3 while a score of 0 is the least favorable patient outcome.

Time frame: Day 1

Impact on collateral circulation assessed by the Higashida score.

Higashida score offers a non-invasive collateral vessel and tissue perfusion assessment of ischemic tissue. This grading system subdivides the collateral flow into five grades, from grade 0 (no collaterals visible on the ischemic side) to grade 5 (complete and rapid collateral blood flow to the vascular bed in the entire ischemic territory by retrograde perfusion). A grade of 3-5 is considered good collateral formation whereas a grade of 0-2 is considered poor collateral formation after a stroke and is less favorable to the patient's outcome.

Time frame: Day 1

Incidence of hemorrhagic transformation at day 1 measured by routine Magnetic Resonance Imaging (MRI)

European Cooperative Acute Stroke Study (ECASS) classification of potential haemorrhagic transformation which divides hemorrhagic transformation into four subtypes: 1) hemorrhagic infarction type 1 (HI1) such as petechial hemorrhages at the infarct margins; 2) hemorrhagic infarction type 2 (HI2) such as petechial hemorrhages throughout the infarct and no mass-effect attributable to the hemorrhages; 3) parenchymal hematoma type 1 (PH1) such as less than or equal to 30% of the infarcted area minor mass effect attributable to the hematoma and 4) parenchymal hematoma type 2 (PH2) such as greater than 30% of infarct zone substantial mass effect attributable to the hematoma. The most favorable patient outcome being the first classification hemorrhagic infarction type 1 (HI1) and the least favorable patient outcome being the fourth classification parenchymal hematoma type 2 (PH2).

Time frame: Day 1

Complications related to the endovascular procedure

Complications such as: embolism in an another initially not involved vascular territory, dissection, severe vasospasm that needs an intra-arterial treatment, vascular perforation

Time frame: Day 1

Responder analysis to thrombectomy relating Modified Rankin score (mRS) 90 days after stroke to baseline National Institutes of Health Stroke Scale (NIHSS) score.

NIHSS score for each ability is a number between 0 and 4 with 0 being normal functioning and 4 being completely impaired. The patient's NIHSS score is calculated by adding the number for each element of the scale; 42 is the highest score possible. The higher the score, the more impaired a stroke patient is. MRS score from 0 to 6 with 0 being normal functioning and 6 being death, the higher the score the more impaired a stroke patient is. For this study a positive response is defined by : a NIHSS \<7 at admission and a MRS = 0 at Day 90 ; a NIHSS between 8 and 14 at admission and a MRS = 0 or 1 at Day 90 ; a NIHSS \>14 at admission and a MRS = 0 to 2 at Day 90.

Time frame: Day 90