Posterior cerebraL ArTery Occlusion Study

Study Overview
=================
Brief Summary
-----------------
For this retrospective study, the investigators will collect and analyze data of patients who presented with posterior artery occlusion and underwent mechanical thrombectomy (the type of endovascular stroke treatment) and intravenous thrombolysis (the type of non-endovascular stroke treatment). The electronic health records will be queried for the demographic, medical history, and outcomes data of all patients with posterior cerebral artery occlusion who underwent mechanical thrombectomy, intravenous thrombolysis (IVT), or medical management.

Detailed Description
-----------------
The primary aims of the research are to evaluate, in patients presenting with posterior artery occlusion (PCA), whether favorable outcome would be superior for EVT compared to Medically Management (MM), inclusive of intravenous thrombolysis (IVT), as measured by: 90-day modified Rankin Scale (mRS) ordinal shift or decrease in NIH Stroke Scale/Score (NIHSS) by two points at 24 hours or at hospital discharge The secondary aims are to evaluate in patients presenting with PCA occlusion, other outcome and safety metrics: 90-day functional independence, mRS 0-2 90-day excellent outcome, mRS 0-1 Visual field recovery (none, partial, complete) by 90-days rate of reperfusion by modified thrombolysis in cerebral infarction (TICI) scale grade any intracranial hemorrhage symptomatic intracranial hemorrhage mortality In subgroup analysis, the investigators aim to identify subgroups that may confer differential treatment benefit by: location of occlusion on the PCA segment (P1, P2, P3) NIHSS strata (0-6, 7-15,>16) time from symptom onset to treatment (0 to <6h vs 6-24h) posterior circulation (PC) Acute Stroke Prognosis Early Computed Tomography Score (ASPECTS) visual field defect on presentation The investigators hypothesize that greater benefit in outcomes would be seen in EVT treated patients with higher NIHSS, more proximal PCA occlusion, higher PC ASPECTS scores, and shorter time from symptom onset to treatment.

Official Title
-----------------
Endovascular Therapy vs Medical Management of PosterIor Cerebral Artery Occlusion Stroke

Conditions
-----------------
Stroke, Acute Ischemic

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Had an ischemic stroke with isolated posterior cerebral artery occlusion (P1, P2, or P3 segments) and was medically managed or managed with EVT during the study time period. Exclusion Criteria: Patient with documented basilar artery occlusion and concomitant PCA occlusion Patient with documented basilar artery occlusion, migration with secondary PCA occlusion

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 89 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Medical management cohort<br>Patients who have undergone medical management stroke treatment from 1/01/2003 to 01/01/2022; this could include intravenous thrombolysis. | |
| EVT management cohort<br>Patients who have undergone EVT stroke treatment from 01/01/2015 to 01/01/2022 | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in stroke outcome based on modified Rankin Scale (mRS) | The Modified Rankin Scale (mRS) assesses disability in patients who have suffered a stroke and is compared over time to check for recovery and degree of continued disability. Scores can range from 0-6, where 0 is no disability, 5 is disability requiring constant care for all needs, and 6 is death. For this outcome an ordinal shift analysis will be done, assessing all changes across the range from baseline at 90 days. | baseline, 90 days | 
| Change in NIH Stroke Score (NIHSS) | The NIH Stroke Scale/Score (NIHSS) is is a 15-item neurologic examination stroke scale used to evaluate the effect of acute cerebral infarction on the levels of consciousness, language, neglect, visual-field loss, extraocular movement, motor strength, ataxia, dysarthria, and sensory loss. Scores can range from 0 to 42 and higher scores are associated with more severe stroke: 1-4= Minor stroke, 5-15= Moderate stroke, 15-20= Moderate/severe stroke, and 21-42 =Severe stroke. | baseline, 7 days | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Posterior occlusion artery (PCA), Intravenous thrombolysis (IVT), Endovascular therapy (EVT), Modified Rankin Scale (mRS)