The Akershus Study of Ischemic Stroke and Thrombolysis -1

Study Overview
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Brief Summary
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This observational study comprises consecutively patients with cerebrovascular diseases admitted to the Stroke Unit at Akershus University Hospital in Norway. Akershus University Hospital is the largest emergency care hospital in Norway and has a catchment area covering a population of 550.000, which is approximately 10 % of the Norwegian population and reasonably representative according to data from Statistics Norway. The hospital is public and serving both as a primary hospital and a university hospital. Due to the Norwegian, national, all-covering health-insurance, all patients enter the hospital and are considered for further in-patient care on the same conditions. The hospital has a stroke unit classified as a comprehensive stroke center according to European Stroke Organisation standards. Acute stroke management follows national and international guidelines. Overall, the ASIST-1 study will investigate management, outcome and prognosis of stroke and stroke care pathways and later follow up in primary care using several approaches combining existing clinical data from a representative population with different Norwegian health registries. Parts of the study are retrospective with prospective follow-up by health registries and parts of the study are prospective.

Detailed Description
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Aims i) to describe the use of the stroke fast track and the proportion of all those evaluated in the fast track actually treated with intravenous thrombolysis, ii) to identify reasons for not giving thrombolysis in patients with acute stroke symptoms < 4.5 hours at admission to hospital, iii) to investigate whether or not some of these patients that did not receive thrombolysis actually could have been given thrombolysis, iv) to investigate the outcome of patients in the stroke fast track treated or not treated with thrombolysis (or endovascular thrombectomy), v) to investigate differences between stroke and stroke mimics for patients reaching the hospital within or outside the thrombolysis time window of 4.5 hours, vi) to investigate differences between stroke subtypes (both ischemic and hemorrhagic) and stroke mimics for patients reaching the hospital within or outside the thrombolysis time window of 4.5 hours, vii) to investigate outcomes for patients with acute ischemic stroke, hemorrhagic stroke, transient ischemic attack (TIA) or stroke mimics, viii) to investigate predictors and factors related to functional outcome for patients with acute ischemic stroke, hemorrhagic stroke, TIA or stroke mimics, ix) to describe the epidemiology of large vessel occlusions in a representative hospital population, x) to describe hemorrhagic stroke in a representative hospital population, xi) whether risk factors, acute blood pressure variability or imaging (CT, angiography, perfusion or MRI) may predict diagnosis or outcome at discharge, 3 months, 12 months and 2 years for the ASIST-1 population, xii) whether risk factors, acute blood pressure variability or imaging (CT, angiography, perfusion or MRI) may predict outcome at discharge, 3 months, 12 months and 2 years for different sub-types of stroke, xiii) to investigate readmission until 5 years after initial admission for acute stroke symptoms xiv) whether deep learning-based assessment of acute phase CT, CT perfusion and CT angiography can reliably identify infarct core, penumbra and large-vessel occlusion, estimate reliably collateral score, predict risk of adverse events, or guide target blood pressure during acute and subacute ischemic stroke specialized treatment, xv) whether deep learning-based assessment of acute phase CT, CT perfusion and CT angiography or MRI can predict clinical outcome in different types of stroke, xvi) whether deep learning-based assessment of acute phase CT, CT perfusion, CT angiography or MRI can be used for automatic detection of hematoma volume and localization in hemorrhagic stroke xvii) whether deep learning-based assessment of acute phase CT or MRI can predict risk of new incidents after a hemorrhagic stroke and thus guide the clinicians to whether or not patients should be started/re-started on anti-platelet therapy or anticoagulation xviii) to investigate secondary prevention after different subtypes of stroke and the adherence of statins, anti-platelet therapy, anti-coagulation and blood pressure treatment up to 5 years after stroke, also in relation to readmission rates and long-term mortality xix) to prospectively investigate quality in terms of treatment, complications, prognosis and predictive factors of all patients given thrombolysis and/or thrombectomy at Ahus 2019-2025 xx) to investigate the changes in prehospital delay, the use of stroke fast track, stroke pathways and treatment over time (2012-2025).

Official Title
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The Akershus Study of Ischemic Stroke and Thrombolysis -1 (ASIST-1) Epidemiology, Clinical and Radiological Presentation and Treatment of Cerebrovascular Disease and Stroke Mimics in a Norwegian Population

Conditions
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Stroke, Acute, Intracerebral Hemorrhage, Stroke, Ischemic, TIA

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Cerebrovascular diseases (acute ischemic stroke, intracerebral hemorrhage, transient ischemic attack) or stroke mimics Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Intravenous thrombolysis (IVT)<br>All patients treated with IVT in the acute stroke care pathway 2012-2025 | |
| Intracerebral hemorrhage (ICH)<br>All patients with intracerebral hemorrhage 2012-2019 | |
| Acute ischemic stroke (AIS) and Intracerebral hemorrhage (ICH)<br>All patients with acute ischemic stroke or intracerebral hemorrhage 2015-2017 | |
| Stoke care pathway<br>All patients admitted to the stroke care pathway (ischemic stroke, intracerebral hemorrhage, transient ischemic attack and stroke mimics) 2015-2017 | |
| Endovascular treatment<br>All stroke patients treated with endovascular treatment 2012-2025 | |
| Cerebellar hematoma (cICH)<br>All patients with cerebellar hematoma 2008-2019 | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Large vessel occlusion in a representative Norwegian population | Incidence of large vessel occlusion 2015-2017 | Baseline 2015-2017 | 
| Functional status | modified Rankin Scale (mRS) 0-6 (0 normal, 6 dead) for all groups | 3 months | 
| Functional status | modified Rankin Scale (mRS) 0-6 (0 normal, 6 dead) for all groups | Index discharge from hospital, usually up to 1 month | 
| Mortality | Number dead vs total number of cases all groups | In-hospital, usually up to 1 month | 
| Mortality | Number dead vs total number of cases all groups | 3 months | 
| Mortality | Number dead vs total number of cases all groups | 12 months | 
| Mortality | Number dead vs total number of cases all groups | 24 months | 
| Mortality | Number dead vs total number of cases all groups | 5 years | 
| Diagnostic precision of different published clinical screening scales of stroke and large vessel occlusion | Diagnostic precision, accuracy and validity of clinical screening scales | Baseline 2015-2017 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reasons for not giving thrombolysis in patients with acute stroke symptoms < 4.5 hours | Number of cases treated with thrombolysis vs number of cases evaluated in the acute stroke care pathway | Baseline 2015-2017 | 
| Functional outcome of patients in the stroke fast track treated or not treated with thrombolysis (or endovascular thrombectomy), | Modified Rankin Scale (mRS) 0-6 (0 normal, 6 dead) | 3 months | 
| Mortality of patients in the stroke fast track treated or not treated with thrombolysis (or endovascular thrombectomy), | Mortality | 3 months | 
| Functional outcome after 1 year of patients in the stroke fast track treated or not treated with thrombolysis (or endovascular thrombectomy), | modified Rankin Scale (mRS) 0-6 (0 normal, 6 dead) | 1 year | 
| Mortality after 1 year of patients in the stroke fast track treated or not treated with thrombolysis (or endovascular thrombectomy), | Mortality | 1 year | 
| Functional outcome at discharge of patients in the stroke fast track treated or not treated with thrombolysis (or endovascular thrombectomy), | modified Rankin Scale (mRS) 0-6 (0 normal, 6 dead) | Discharge after index admission, usually up to 1 month | 
| Mortality at discharge of patients in the stroke fast track treated or not treated with thrombolysis (or endovascular thrombectomy), | Mortality | Discharge after index admission, usually up to 1 month | 
| Re-admission | Number of new re-admission among included patients | Baseline to five years | 
| New prescriptions | Type of new prescriptions | Baseline to five years | 
| Use of anti-coagulation in the long-term | Number of patients treated with anti-coagulation | Baseline to five years | 
| Use of anti-platelet therapy in the long-term | Number of patients treated with anti-platelet therapy | Baseline to five years | 
| Use of cholesterol-lowering drugs in the long-term | Number of patients treated with cholesterol-lowering drugs | Baseline to five years | 
| Use of anti-hypertensive drugs in the long-term | Number of patients treated with anti-hypertensive drugs | Baseline to five years | 
| Use of anti-diabetics in the long-term | Number of patients treated with anti-diabetics | Baseline to five years | 
| Health care utilisation | Number of new health care system contacts | Baseline to five years | 
| Prehospital delay | Changes in prehospital delay (minutes) | 2012-2025 | 
| Time of stroke fast track | Changes in the use of stroke fast track (minutes) | 2012-2025 | 
| Use of stroke fast track | Changes in the use of stroke pathways (proportion) | 2012-2025 | 
| Treated in the stroke fast track | Changes in proportion treated over time | 2012-2025 | 
| Blood pressure variability baseline (diastolic, systolic and pulse pressure) | Different BP measurements from general practitioners, ambulance, hospital and follow-up | Baseline | 
| Blood pressure variability discharge after index (diastolic, systolic and pulse pressure) | Different BP measurements from general practitioners, ambulance, hospital and follow-up | Discharge after index admission, usually up to 1 month | 
| Blood pressure variability follow-up (diastolic, systolic and pulse pressure) | Different BP measurements from general practitioners, ambulance, hospital and follow-up | Follow-up (3 to 6 months) |