Atrial CMR in Patients With CVA of Unknown Source and no Known AF (CARM-AF)

Atrial Cardiac Magnetic Resonance Imaging in Patients With Embolic Stroke of Unknown Source Without Documented Atrial Fibrillation

This research study will investigate a new method for identifying which patients should be offered blood thinners or therapies to reverse the underlying causes after stroke.

Atrial fibrillation(AF) is the primary risk factor for ischaemic stroke, increasing the risk by up to 5-fold. In AF, the upper heart chambers don't pump blood effectively into the lower chambers. When this happens, a blood clot can form, dislodge and leave the heart blocking an artery in the brain and cause a stroke. However, AF is often an intermittent condition and therefore difficult to diagnose. As such, there are a group of patients in whom no cause of their stroke can be identified.

In this study, we will recruit 92 patients from Guy's and St Thomas' Hospital, Princess Royal University Hospital and King's College London.

As part of routine clinical care, patients undergo insertion of an Implantable Loop Recorder (CE Marked device), a minimally invasive procedure that allows accurate beat-to-beat monitoring to identify patients who develop intermittent AF post-stroke. We will request access to the data collected from this device and perform atrial MRI imaging in these patients to compare the findings between patients that do and do not have AF. If we show that atrial MRI scans are significantly different between patients with and without AF, we will use this information to support a trial of starting appropriate therapies (e.g. blood thinners) in these patients on the basis of MRI findings. This approach would have the advantage of enabling therapies to be offered to the right patients earlier and prevent repeat, potentially disabling stroke.

Study Overview

• Status: Recruiting
• Conditions: Atrial Fibrillation; Stroke, Ischemic
• Intervention / Treatment: Diagnostic test: Cardiac MRI

• Study Type: Observational
• Enrollment (Anticipated): 92

Contacts and Locations

• Study Contact: Name: Irum D Kotadia, BSc MBBS; Phone Number: 02071887188; Email: irum.kotadia@kcl.ac.uk

Study Locations

• United Kingdom
  • London, United Kingdom
    • Not yet recruiting
    • King's College Hospital
    • Contact: James Harrison
  • London, United Kingdom
    • Recruiting
    • Guy's and St Thomas' Hospital
    • Contact: Irum Kotadia, MBBS, BSc; Email: irum.kotadia@kcl.ac.uk
  • Orpington, United Kingdom
    • Recruiting
    • Princess Royal University Hospital
    • Contact: James Harrison

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients will be recruited during outpatient clinics and inpatient stays

Description

Inclusion Criteria:

Patients will be recruited within 3 months of an acute ischaemic stroke. It must also be feasible to perform a cardiac MRI on all patients enrolled within 3 months of the acute ischaemic stroke.

Inclusion criteria includes patients with:

• Patient consent or advice given by consultee can be obtained
• Confirmed acute ischaemic stroke with evidence on brain CT and/or MRI within 3 months of study enrolment • Ischaemic stroke of unknown source Expected survival >12 months.
• At least one additional stroke risk factor (i.e. CHA2DS2VASc>=3)
• Sinus rhythm on 12 lead ECG, telemetry and a regular pulse on clinical examination
• Above 18 years of age

Exclusion Criteria:

• Unable to obtain patient consent or advice by consultee
• History of atrial fibrillation
• Atrial fibrillation detected on ECG and/or telemetry (AF duration of at least 30 seconds required for diagnosis)
• eGFR <30ml/min
• Indication for pacemaker/implantable cardioverter-defibrillator
• Contra-indication to undergo cardiac MRI (e.g. severe claustrophobia, unable to lie flat for prolonged period, contrast allergy)
• Carotid stenosis >50% on Duplex ultrasound associated with anterior circulation infarction
• Vertebrobasilar stenosis >50% on CT/MR angiography associated with posterior circulation infarction
• Single, isolated lacunar stroke with a corresponding lacunar infarct on brain CT/MRI
• Specific aetiology for cause of stroke (e.g. arteritis, dissection, drug abuse)

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Atrial Fibrillation Group	Diagnostic test: Cardiac MRI; These are routinely performed for many cardiac conditions, including atrial arrhythmias. The adverse effects are small but include claustrophobia and metallic objects. Therefore all patients will be counselled prior to the scans by an experienced MRI practitioner and standard measures will be taken to avoid distress during the scan. Furthermore, patients will be screened using routine clinical protocols in order to avoid any harm due to interaction of the MRI scanner with metallic objects.
Non-Atrial Fibrillation Group	Diagnostic test: Cardiac MRI; These are routinely performed for many cardiac conditions, including atrial arrhythmias. The adverse effects are small but include claustrophobia and metallic objects. Therefore all patients will be counselled prior to the scans by an experienced MRI practitioner and standard measures will be taken to avoid distress during the scan. Furthermore, patients will be screened using routine clinical protocols in order to avoid any harm due to interaction of the MRI scanner with metallic objects.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
AF Predictors	Determine if atrial CMR imaging can predict the occurrence of atrial fibrillation in advance of the clinical arrhythmia in patients with confirmed ischaemic stroke	1 year

Collaborators and Investigators

• Sponsor: Guy's and St Thomas' NHS Foundation Trust
• Collaborators: King's College London; King's College Hospital NHS Trust; British Heart Foundation
• Investigators: Principal Investigator: Steven Williams, MBChB PhD, King's College London

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 1, 2020
• Primary Completion (ANTICIPATED): August 1, 2022
• Study Completion (ANTICIPATED): August 1, 2023

Study Registration Dates

• First Submitted: September 14, 2020
• First Submitted That Met QC Criteria: September 14, 2020
• First Posted (ACTUAL): September 18, 2020

Study Record Updates

• Last Update Posted (ACTUAL): May 3, 2021
• Last Update Submitted That Met QC Criteria: April 28, 2021
• Last Verified: October 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Arrhythmias, Cardiac; Stroke; Ischemic Stroke; Atrial Fibrillation
• Other Study ID Numbers: 269654

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No