Clinical Relevance of Microbleeds In Stroke

Study Overview
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Brief Summary
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Study I: CROMIS-2 (AF) Prospective cohort study of patients anticoagulated after cardioembolic stroke An observational inception cohort study (n=1425) of patients throughout the United Kingdom (UK) - (79 hospitals) started on best practice oral anticoagulant (without prior use) for presumed cardioembolic ischaemic stroke due to non-valvular AF with follow up for the occurrence of intracerebral haemorrhage (ICH) and ischaemic stroke for an average of two years. The main baseline exposures (risk factors of interest) are the presence of cerebral microbleeds (CMBs) on magnetic resonance imaging (MRI), and genetic polymorphisms in candidate genes with potential functional relevance to ICH risk. Study II: CROMIS-2 (ICH) Observational and genetics study of intracerebral haemorrhage The investigators will also recruit 600 patients admitted to participating centres with ICH (with a target of at least 300 anticoagulant-related ICH cases) and collect DNA to increase the power of the genetic studies. The investigators will collect clinical and imaging data from these ICH cases to investigate risk factors associated with anticoagulant-related ICH compared to non anticoagulant-related ICH.

Detailed Description
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Background Over the last decade, increasing use of oral anticoagulants to prevent cardioembolic ischaemic stroke due to atrial fibrillation (AF) in an ageing population has led to a five-fold increase in the incidence of anticoagulant-related intracranial haemorrhage (ICH) - a rare but unpredictable and catastrophic complication. Cerebral microbleeds (CMBs) on magnetic resonance imaging (MRI) may predict ICH risk, as may genetic polymorphisms influencing brain small-vessel integrity or anticoagulation stability. Aims To establish the value of CMBs and genetic factors in predicting symptomatic ICH following best practice oral anticoagulation to prevent recurrent ischaemic stroke due to AF. Methods CROMIS-2: Study I (AF) - Prospective, multicentre, inception cohort study in 1425 patients with ischaemic stroke due to AF started on best practice oral anticoagulation. Patients will have genetic testing and standardized MRI including Gradient recalled Echo (GRE) at baseline, with follow-up by postal questionnaire (and clinical assessment or medical records surveillance after suspected events), and where possible there will be an in person clinical assessment at 2 years. The investigators will compare the rate of symptomatic ICH between CMB and CMB-free patients and test for associations with plausible candidate genes. The investigators aim to develop and validate a risk model to predict symptomatic ICH following best practice oral anticoagulation to prevent recurrent ischaemic stroke due to AF. CROMIS-2: Study II (ICH) - An observational study of ICH investigating genetic, clinical and radiological risk factors associated with anticoagulant-related ICH. The investigators will recruit patients admitted to participating centres with ICH (with a target of at least 300 anticoagulant-related ICH cases) and collect DNA to increase the power of the genetic studies. The investigators will collect clinical and imaging data from these ICH cases to investigate risk factors associated with anticoagulant-related ICH compared to non anticoagulant-related ICH. Expected outcomes A successful predictive model for ICH risk after best practice oral anticoagulation for AF will help to determine whether genetic or CMB screening should be used in clinical practice and future trials. New genetic, clinical and radiological risk factors associated with anticoagulant-related ICH will be identified.

Official Title
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Microbleeds and Genetic Risk Factors to Predict the Risk of Intracranial Haemorrhage in Patients Treated With Anticoagulation Following Cardioembolic Stroke Due to Atrial Fibrillation

Conditions
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Atrial Fibrillation (AF), Stroke, Intracerebral Haemorrhage (ICH)

Participation Criteria
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Eligibility Criteria
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Study I: CROMIS-2 (AF) Inclusion criteria: Adult (≥18y; no upper limit) patients with a clinical diagnosis of non-valvular AF (verified by ECG) with intention to treat with best practice oral anticoagulants (e.g. warfarin) Previous ischaemic stroke or TIA diagnosed by treating clinician All patients must be able to have GRE MRI before (or within 1 week) of starting best practice oral anticoagulant Exclusion Criteria: Any MRI contraindications Previous use of oral anticoagulation Definite contra-indication to oral anticoagulation Serious head injury (resulting to loss of consciousness) Study II: CROMIS-2 (ICH) Inclusion criteria: • Adult (>18y) patients treated at participating centres with confirmed ICH (confirmed on CT or MRI scans) with or without a history of anticoagulant use at the time of the ICH Exclusion criteria: Known underlying structural cause for ICH (e.g arteriovenous malformation, tumour, cavernoma, intracranial aneurysm, haemorrhagic transformation of an infarct) Major head trauma (causing loss of consciousness and though to be sufficient to have caused the ICH) in previous 24 hours

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 |
| --- | --- |
| Study I (AF)<br>Prospective cohort study of patients anticoagulated after cardioembolic stroke started on best practice oral anticoagulant (without prior use) for presumed cardioembolic ischaemic stroke due to non-valvular AF with follow up for the occurrence of ICH, ischaemic stroke and cognitive function for an average of two years. Our main baseline exposures (risk factors of interest) are the presence of CMBs on MRI, and genetic polymorphisms in candidate genes with potential functional relevance to ICH risk. | |
| Study II (ICH)<br>Observational and genetics study of intracerebral haemorrhage Patients with ICH (non anticoagulant-related ICH cases and anticoagulant-related ICH cases). | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Symptomatic intracranial haemorrhage | Symptomatic intracranial haemorrhage (confirmed on brain imaging). Intracranial haemorrhage includes any bleeding within the skull, regardless of the site. The investigators will record the incidence of different haemorrhage subtypes (intracerebral, subdural, extradural, subarachnoid). This will be assessed using hospital records, General Practitioner (GP) follow up and National Health Service (NHS) information data system. | 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ischaemic stroke | Patient experiencing an ischaemic stroke during 2 year follow up.This will be assessed using hospital records, General Practitioner (GP) follow up and National Health Service (NHS) information data system. | 24 months | 
| Transient Ischaemic Attack (TIA) | Patient experiencing a TIA after recruitment during 2 year follow up.This will be assessed using hospital records, General Practitioner (GP) follow up and National Health Service (NHS) information data system. | 24 months | 
| Death | Patient death (of any cause). Assessed by General Practitioner (GP) follow up, recruiting hospital records and National Health Service (NHS) Information Centre data systems. | 24 months | 
| Any other major haemorrhagic events other than ICH | Prolonged epistaxis, cutaneous bruising, gastrointestinal bleeding, haematuria, muscle haematoma, haemarthrosis. Assessed by General Practitioner (GP) follow up, recruiting hospital records and National Health Service (NHS) Information Centre data systems. | 24 months | 
| Long term physical disability | Assessed by administering Modified Rankin Score (mRS) to patients at 6,12 and 24 months via patient questionnaire. | 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Microbleeds