WSO December 2023 – Issue 3 - 1210

1210
International Journal of Stroke 18(10)
Results: Of the 1047 tPA-eligible ischemic stroke patients, 254 were with PD (baseline mRS 2-5) and 793 were
without PD (baseline mRS 0-1). Although PD patients had worse 90-day uw-mRS, higher mortality, more health-care
utilization, and worse quality of life than non-disabled patients, 53% returned to at least their baseline mRS, those
treated faster had better outcome, and there was no increased bleeding risk. Comparing PD patients treated by MSU
versus EMS, 90-day uw-mRS was 0.42 versus 0.36 (p = 0.07) and 57% versus 46% returned to at least their baseline
mRS. There was no interaction between disability status and MSU versus EMS group assignment (p = 0.67) for 90-day
uw-mRS.
Conclusion: PD did not prevent the benefit of faster treatment with tPA in the BEST-MSU study. Our data support
inclusion of PD patients in the MSU management paradigm.
Keywords
Acute stroke therapy, mobile stroke unit, pre-existing disability, tPA, ischemic stroke, clinical trial
Received: 1 April 2023; accepted: 1 June 2023
Introduction
Methods
In the United States, approximately 26% of adults are disabled,1-3
and management of acute stroke patients with preexisting
disability (PD) is uncertain. One of the approved
treatments for acute ischemic stroke (AIS) is intravenous
thrombolysis with tissue plasminogen activator (tPA;
Activase-Genentech). Current guidelines state it is reasonable
to give tPA to AIS patients with PD, although the recommendation
is weak since PD was an exclusion criterion
in most acute stroke clinical trials.4,5 Management of PD
patients should consider patients' quality of life and the values
and preferences of patients and their families. Although
mortality may be higher compared to patients with no preexisting
disability (ND), there may still be a net benefit of
tPA treatment for AIS patients with PD.4,5
The use of tPA has recently expanded to mobile stroke
units (MSUs). MSUs are ambulances equipped with a computed
tomography scanner and a point-of-care laboratory,
where tPA can be started in the prehospital setting, increasing
the number of patients treated within the first " golden
hour. " 6-8 In the BEST-MSU multicenter study (Benefits of
Stroke Treatment on a Mobile Stroke Unit compared to
Standard Management
(ClinicalTrials.gov
Identifier:
NCT02190500)), faster and more frequent tPA treatment was
associated with better clinical outcomes. Furthermore, in
BEST-MSU, roughly 25% of patients in the primary analytic
cohort had PD with baseline modified Rankin Scale (mRS)
of 2-5.6 Thus BEST-MSU provides a unique opportunity to
prospectively examine clinical outcome associated with
timely tPA provision in a large cohort of patients with PD.
In this pre-specified BEST-MSU secondary analysis, we
aimed to describe the baseline demographics, tPA treatment
metrics, and outcomes in AIS patients with PD compared to
those with ND. We then sought to compare the outcomes of
MSU versus standard management by emergency medical
services (EMS) for tPA-eligible patients with PD.
International Journal of Stroke, 18(10)
Data availability
Data supporting the findings are available from the principal
investigator (James C Grotta) of the BEST-MSU study.
Study setting and data cohort
The BEST-MSU study was an observational, prospective,
multicenter, cluster-randomized trial comparing clinical
outcomes in tPA-eligible patients who received care by a
MSU versus standard management by EMS.9 The trial
enrolled patients from seven sites in the United States from
May 2014 to August 2020. Each MSU was staffed by a vascular
neurologist (on-board or by telemedicine), a critical
care nurse, a CT technologist, and one or two paramedics.
The study was approved by the Institutional Review Boards
of each of the participating institutions and written informed
consent was obtained from all patients. Patients were
enrolled into the study if screening criteria were met for tPA
treatment. The primary analytic cohort was all tPA-eligible
patients enrolled in the study. The criteria and process for
determining tPA eligibility by an independent vascular neurologist,
blinded to treatment status and MSU versus EMS
group allocation, have been published.6,9 All patients were
followed for a full year after hospital discharge, with data
collected at hospital discharge and every 3 months on disability,
mortality, health-care utilization, and quality of life.
Study variables
Age, sex, race, ethnicity, baseline National Institutes of Health
Stroke Scale (NIHSS), pre-existing comorbidities, living
facility, caregivers need, and time metrics were recorded. The
pre-stroke mRS was evaluated either on the MSU or during
admission to the emergency department (ED) by the MSU
nurse or vascular neurologist, who interviewed the patient,
http://www.ClinicalTrials.gov
WSO December 2023 – Issue 3

Table of Contents for the Digital Edition of WSO December 2023 – Issue 3
