Plain English Summary
Background and study aims
Mechanical thrombectomy (MT) is a highly successful treatment for acute ischemic stroke triggered by a blockage in a large blood vessel (large vessel occlusion; LVO). Approximately 15,000 ischaemic strokes are eligible for MT in the UK each year. With the growing technological advances in both arterial imaging and thrombectomy techniques, this number will increase in the future. Due to the proximal site of arterial occlusion in LVO, these strokes tend to cause severe disability or death if untreated. Emergency treatment of LVO by MT reduces the chance of long-term disability and mortality and earlier treatment produces significantly better outcomes and health care savings, but optimising delivery faces many challenges due to:
1. Stroke-like symptoms that mimic LVO can also be due to lacunar stroke from small vessel infarction, intracerebral haemorrhage, transient ischaemic attack (TIA) and non-vascular conditions such as seizures and migraines. Ruling in LVO from such a complex cohort of ‘suspected stroke’ patients currently requires specialist assessment and brain imaging only performed in-hospital;
2. Less than a third of stroke units are regional MT providers, meaning that many patients are initially taken to their local stroke unit, and then transferred to a thrombectomy centre. This leads to a median treatment delay of 2 hours by the time patients are identified and transferred between sites, with every 1-hour of delay increasing the chance of disability and dependence by 20%.
Currently, no tools are used in the pre-hospital to identify LVO and redirect suspected patients to regional MT providers.Tools to help ambulance clinicians diagnose LVO and transport patients immediately to a thrombectomy centre are vital.
This clinical feasibility study aims at assessing the feasibility of using the LVOne test during ambulance clinical assessment. LVOne is a new finger-prick blood test which is designed to help ambulance clinicians diagnose ischaemic strokes.
The test kit consists of 2 separate blood tests. One of them measures D-dimer. The D-dimer levels are high when a stroke is associated with a blood clot, i.e. ischaemic stroke. The second test measures Glial Fibrillary Acidic Protein (GFAP) which is elevated when patients have haemorrhagic stroke (i.e. brain bleed). You will receive training and guidance on how to use and interpret the LVOne test.
Prior studies have shown that the LVOne test has 90% accuracy in identifying ischaemic strokes.
The purpose of the RADIOS study is to determine whether the LVOne test can be used by ambulance staff to diagnose patients with ischaemic strokes. If they can, this could see these stroke patients being assessed before arriving at hospital.
However, patients in this study will be assessed and treated in the standard way, and the results of the LVOne test will not be acted upon.
Future studies will explore use of the LVOne test in ambulance setting to reduce treatment times for stroke patients and improve their recovery.
Who can participate?
All patients evaluated by ambulance clinicians for a new acute suspected stroke will be evaluated for study eligibility.
What does the study involve?
The study includes performing the LVOne test, which, from the patient perspective, involves collecting a fingerstick blood sample and testing with the device.
What are the possible benefits and risks of participating?
There are no benefits for the participants and we do not expect any significant risk associated to the test procedure as this study is observational and the intervention involves a fingerstick blood sample which is known to be very safe.
Where is the study run from?
Pockit diagnostics Ltd, T/A Upfront diagnostics (UK)
When is the study starting and how long is it expected to run for?
April 2024 to September 2024
Who is funding the study?
Pockit diagnostics Ltd, T/A Upfront diagnostics (UK)
Who is the main contact?
Dr Edoardo Gaude, edoardo.gaude@pockitdx.co.uk
Study website
Contact information
Type
Public, Scientific, Principal Investigator
Contact name
Dr Edoardo Gaude
ORCID ID
http://orcid.org/0000-0001-8523-7792
Contact details
University Of Cambridge CRUK
Robinson Way
CAMBRIDGE
CB2 0RE
United Kingdom
+44 1223 363608
edoardo.gaude@pockitdx.co.uk
Additional identifiers
EudraCT/CTIS number
Nil known
IRAS number
332951
ClinicalTrials.gov number
Nil known
Protocol/serial number
REC-292, IRAS 332951
Study information
Scientific title
Rapid Ambulance DIagnosis Of Stroke (RADIOS): a pre-hospital feasibility study
Acronym
RADIOS
Study hypothesis
Ambulance clinicians find the LVOne test feasible to use during ambulance assessment.
Ethics approval(s)
Submitted 29/04/2024, Cambridge Central Research Ethics Committee (Equinox House, City Link, Nottingham, NG2 4LA, United Kingdom; +44 207 1048098; cambridgecentral.rec@hra.nhs.uk), ref: 23/EE/0226
Study design
Prospective feasibility cohort study
Primary study design
Observational
Secondary study design
Cohort study
Study setting(s)
Paramedicine
Study type
Diagnostic, Other
Patient information sheet
Not available in web format, please use contact details to request participant information sheet.
Condition
Suspected stroke
Intervention
The intervention associated to this study is performing the LVOne test, which, from the patient perspective, involves collecting a fingerstick blood sample and testing with the device. The total observation is limited to the duration of in-hospital stay and there is no follow-up.
The LVOne test consists of two portable lateral flow assays: assay 1 measures blood D-dimer concentration and assay 2 measures blood GFAP concentration (Upfront diagnostics). The main analysis will include ambulance clinicians’ opinions on the feasibility of the LVOne test during routine ambulance visits for the pre-hospital evaluation of LVO stroke.
Intervention type
Device
Pharmaceutical study type(s)
Not Applicable
Phase
Not Applicable
Drug/device/biological/vaccine name(s)
LVOne
Primary outcome measure
Expert opinions on the feasibility of the LVOne test during routine ambulance visits. The method used to collect this data is qualitative evaluation in the form of a questionnaire.
Secondary outcome measures
There are no secondary outcome measures
Overall study start date
29/04/2024
Overall study end date
30/09/2024
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Attended by study trained ambulance clinician
2. Evaluated for suspected acute stroke
3. Within 6 hours of symptom onset
4. Age >18 years
5. Local hospital is Cambridge University Hospital (or other thrombectomy-capable hospital)
Participant type(s)
Patient
Age group
Adult
Lower age limit
18 Years
Upper age limit
99 Years
Sex
Both
Target number of participants
30
Participant exclusion criteria
1. Witnessed seizure at presentation
2. Hypoglycaemia, (blood glucose <3mmol/l)
3. Severe frailty or limited life expectancy <6 months
4. Patient is not conveyed to Cambridge University Hospital (or other thrombectomy-capable hospital)
Recruitment start date
01/07/2024
Recruitment end date
30/09/2024
Locations
Countries of recruitment
England, United Kingdom
Study participating centre
Cambridge University Hospitals NHS Foundation Trust
Cambridge Biomedical Campus
Hills Road
Cambridge
CB2 0QQ
United Kingdom
Study participating centre
East of England Ambulance Service NHS Trust
Unit 3
Whiting Way
Melbourn
Royston
SG8 6NA
United Kingdom
Sponsor information
Organisation
Pockit diagnostics Ltd, T/A Upfront diagnostics
Sponsor details
CRUK Cambridge Institute
Cambridge
CB2 0RE
England
United Kingdom
+44 1223330808
elizabeth.warburton5@nhs.net
Sponsor type
Industry
Website
Funders
Funder type
Industry
Funder name
Pockit diagnostics Ltd, T/A Upfront diagnostics
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
Results may be printed in public medical journals, presented at scientific conferences and meetings. No personally identifiable data will be released in publications or to third parties.
Intention to publish date
31/03/2025
Individual participant data (IPD) sharing plan
The datasets generated during and/or analysed during the current study will be available upon request from Edoardo Gaude, edoardo@upfrontdiagnostics.com
IPD sharing plan summary
Available on request
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|