Rapid Assay Diagnostic for Acute Stroke Recognition (RADAR): study protocol for a diagnostic accuracy study

Area of Science:

• Neurology
• Medical Diagnostics
• Biomarkers

Background:

• Large-vessel occlusion (LVO) stroke requires time-critical thrombectomy, often necessitating patient transfer to specialized centers.
• Current transfer protocols can lead to significant delays in treatment initiation.
• Accurate and rapid diagnostic tools are needed to streamline patient selection and transfer.

Purpose of the Study:

• To evaluate the diagnostic accuracy of a novel rapid portable test for identifying LVO stroke.
• To assess the potential of the test in selecting patients for direct admission to thrombectomy-capable centers.

Main Methods:

• Prospective observational cohort study (RADAR) in English stroke units.
• Index test: 'LVOne test' using fingerprick blood to detect d-dimer and glial fibrillary acidic protein.
• Reference standard: Adjudicated CT/MRI brain±CT/MR angiography to confirm stroke type and LVO.

Main Results:

• The study aims to determine sensitivity, specificity, and predictive values for LVO stroke detection.
• A primary analysis population of 276 participants is powered to detect a test specificity of 92% for LVO stroke.
• A total study population of 552 participants will allow evaluation in milder symptoms and unknown onset times.

Conclusions:

• The 'LVOne test' shows promise as a rapid, portable diagnostic tool for LVO stroke.
• Successful implementation could optimize patient pathways and reduce treatment delays.
• Further validation in broader populations will confirm its clinical utility.