BEnefits of Stroke Treatment Delivered Using a Mobile Stroke Unit "BEST-MSU"


Phase 2/3 Results N/A

Trial Description

The primary goal of this project is to carry out a trial comparing pre-hospital diagnosis and treatment of patients with stroke symptoms using a Mobile Stroke Unit (MSU) with subsequent transfer to a Comprehensive Stroke Center (CSC) Emergency Department (ED) for further management, to standard pre-hospital triage and transport by Emergency Medical Services (EMS) to a CSC ED for evaluation and treatment (Standard Management-SM).

Detailed Description

There are many ways that use of a MSU might prove valuable in stroke patients, but we will focus on acute ischemic stroke (AIS) and treatment with IV tissue plasminogen activator (tPA) within 4.5 hours of symptom onset since that is the most evidence based effective emergency treatment for the most prevalent stroke diagnosis. We hypothesize that the MSU pathway will result in an overall shift towards earlier evaluation and treatment, particularly into the first hour after symptom onset, leading to substantially better outcome. We also hypothesize that as a result of improved clinical outcomes resulting from earlier treatment, the costs of a MSU program will be offset by a reduction in the costs of long term stroke care and increase in quality adjusted life years, thereby supporting more widespread use of this technology. To make MSU deployment more practical, we will confirm that a Vascular Neurologist (VN) on board the MSU can be replaced by a remote VN connected to the MSU by telemedicine (TM) thereby reducing manpower requirements and costs.
The successful completion of this project will provide data on important outcomes and costs associated with the use of MSU vs SM in the United States (U.S.) that will help determine the value of integrating MSUs into the pre-hospital environment in this country. Successfully addressing our three Specific Aims (time saved/ complications encountered, utility of TM, and cost effectiveness) will provide critical information that will be needed to determine if and how a subsequent more definitive study should be conducted. We anticipate that emanating from this exploratory study would be a larger multicenter trial carried out in both urban and rural U.S. pre-hospital environments, with treatment orchestrated via TM, and having sufficient power to determine a difference in long term outcome and costs between patients managed on the two pathways, following a study design that will be tested in this exploratory trial. The present study, therefore, is the necessary first step in a process which may dramatically modify the way that acute stroke patients are managed in the U.S.



  • Mobile Stroke Unit Management Other
    Intervention Desc: Mobile Stroke Unit is a standard 12' Houston Fire Department ambulance equipped with point of care lab, CT scanner and staffed by a Vascular Neurologist, Registered Nurse with acute stroke and research experience, CT Technician and a Registered EMT-P. The MSU is dispatched in coordination with Houston, Bellaire and West University fire department/emergency medical services.
    ARM 1: Kind: Experimental
    Label: Mobile Stroke Unit Management
    Description: Acute ischemic stroke patients treated in the Mobile Stroke Unit

Trial Design

  • Allocation: Randomized
  • Masking: Single Blind (Outcomes Assessor)
  • Purpose: Treatment
  • Endpoint: Efficacy Study
  • Intervention: Parallel Assignment
  • Observation: Cohort
  • Perspective: Prospective
  • Sampling: Probability Sample

Trial Population

To be assessed for eligibility (n = 6000) To be enrolled (n = 1200) To be analyzed ("tPA eligible") (n =693) Based on our pilot data in the first 9 months of operation, the MSU is being alerted and dispatched by Criteria 1 above approximately 5 times for every patient that is enrolled into the study by Criteria 2, and 10 times for every patient treated with tPA by Criteria 3. Therefore, we anticipate that slightly over 50% of enrolled patients will be treated with tPA. We calculate that we will need 693 tPA eligible patients (meeting above Criteria 1, 2 and 3) to answer SA 1 allowing for 10% lost to f/u (see Statistical Methods).


Type Measure Time Frame Safety Issue
Primary Time from last seen normal to tPA treatment up to 4.5 hours from symptom onset No
Primary Agreement between on scene Vascular Neurologist vs. Remote (Telemedicine) Vascular Neurologist up to 4.5 hours from symptom onset No
Primary Cost Effectiveness up to 1 year from date of enrollment No
Secondary 90 day Modified Rankin Score 90 days (+/- 10 days) from date of enrollment No
Primary Utility-weighted modified Rankin Scale (uw-mRS) from baseline to 90 days 90 days (+/- 10 days) from date of enrollment No
Secondary Time from symptom onset to tPA treatment up to 4.5 hours from symptom onset No
Secondary Time from symptom onset to Endovascular treatment up to 6 hours from symptom onset No
Secondary Symptomatic intracranial hemorrhage and mortality up to hospital discharge Yes
Secondary Stroke mimics up to hospital discharge Yes