Direct-to-angio approach from loCal hOspitals based on a PoInt-of-care bLOod Test for LVO (COPILOT) is a multi-center, prospective, cluster-randomized crossover trial that will evaluate if the triage assessment to thrombectomy puncture time is shorter after performing the LVOne testing compared to current management standards in patients with suspected large vessel occlusion.

The COPILOT trial utilizes a cluster randomized crossover design within the Sistema de Salud Menonita (SSM) hospital network to evaluate if early detection of large vessel occlusion (LVO) stroke with a novel blood test can accelerate the time from triage assessment to thrombectomy puncture. It will unfold in three phases:

Phase 0 - Baseline Data Collection (3 months): Before the random allocation, all clusters undergo data collection on baseline characteristics and outcome measures to confirm/set a pre-intervention comparison ground. Phase 0 patients will receive the current standard of care. An interim analysis will check recruitment rates and explore the need for additional clusters for adequate study power.

Phase 1 - Intervention and Control (12 months): Clusters are randomized to either the intervention or control group, with the intervention arm implementing the LVOne test and the control arm continuing standard care without the LVOne test. Data analysts remain blinded to group allocation, while an interim analysis revisits recruitment and primary outcomes to assess whether additional clusters are required.

Phase 2 - Crossover (12 months): Clusters switch roles from Phase 1, allowing every cluster to experience both the intervention and control conditions, facilitating within-cluster comparisons. The nature of the intervention prevents the blinding of participants and staff.

Inclusion Criteria:

• Age: 21 to 85 years old
• Language: Speak and understand Spanish or English
• Residence: Resident of Puerto Rico
• Clinical presentation: Suspected acute stroke
• Time of presentation: Monday to Friday, between 8:00 a.m. and 4:00 p.m.
• Time of symptom onset: symptoms are known to have begun within the last 6 hours, OR last known to be well between 6 and 18 hours ago, confirmed by a reliable witness or healthcare professional

Exclusion Criteria:

• Previous healthcare encounter:
• Already assessed at another hospital, and ambulance admission is a transfer for continuing care OR
• Received thrombolysis therapy before consent (e.g., tPA, alteplase)
• Medical History: diagnosed with any of the following in the past 4 weeks: deep vein thrombosis (DVT), pulmonary embolism (PE), arterial embolism, stroke, transient ischemic attack (TIA), long bone fracture, major trauma, surgery under general anesthesia, or head injury requiring hospital admission within the last 4 weeks.
• Modified Rankin Scale: Pre-stroke mRS ≥ 3
• The patient is a pregnant woman
• The patient is under legal custody or deprived of liberty in penitentiary institutions
• The patient is unable to provide informed consent on their own and whose authorized legal representatives are unavailable in person or by telephone during recruitment

The neuro-radiologist(s) who will read patient brain imaging and the expert stroke clinician(s) who will assign a clinical outcome (reference standard) will be blinded to the LVOne test results. Due to the nature of the LVOne and the management implications of a positive test, hospital clinicians will not be blinded to these results.