WSO December 2023 – Issue 3 - 1256

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International Journal of Stroke 18(10)
and infarct volume growth at 24 h, and quality of life and cognitive function at day 90. Safety outcomes (90-day all-cause
mortality, procedural complications, symptomatic intracerebral hemorrhage, and rapid NIHSS score worsening) are
recorded.
Discussion: The MOSTE trial will determine MT efficacy and safety in patients with minor stroke and LVO in the anterior
circulation.
Trial registration: MOSTE Trial. NCT 03796468
Keywords
Acute stroke therapy, clinical trial, mechanical thrombectomy, ischemic stroke, large vessel occlusion, NIHSS 0-5
Received: 10 March 2023; accepted: 7 June 2023
Introduction and rationale
Up to 10% of patients with proximal large vessel occlusion
(LVO) may present minor deficit,1 but are at high risk of
early neurological deterioration,2,3 strongly associated with
poor functional outcome.2 Mechanical thrombectomy (MT)
has become the standard of care for patients with acute
ischemic stroke (AIS) in the anterior circulation secondary
to LVO. However, MT benefit in patients with minor stroke
(National Institutes of Health Stroke Scale, NIHSS,
score ⩽ 5) remains uncertain because these patients were
excluded from randomized clinical trials.4-6 A recent metaanalysis
of observational studies7 suggests similar outcomes
of MT and best medical treatment (BMT) in these
patients. The site of occlusion can modify the effect of
immediate MT, with a potential benefit for patients with
more proximal occlusions.7 Therefore, the current guidelines
recommend MT only for patients with NIHSS
score ⩾ 6.8,9 In case of worsening, patients who received
BMT may undergo secondary MT,2,10-12 but outcome and
recanalization rate may be less good than with immediate
MT.10
The MOSTE trial objective is to determine the safety
and efficacy of immediate MT for increasing the excellent
outcome at day 90 in patients with AIS due to anterior circulation
LVO and NIHSS score ⩽ 5.
Methods
Design
MOSTE is an international, multicenter, prospectively randomized
into two parallel (1:1) arms, open-label, with
blinded endpoint trial to demonstrate the superiority of
immediate MT plus BMT (experimental arm), compared
to BMT (control arm), to improve the 90-day outcome in
patients with minor AIS (NIHSS score ⩽ 5) and LVO in
the anterior circulation. In the control arm, secondary MT
is allowed in case of deterioration within 24 h
International Journal of Stroke, 18(10)
Randomization
Eligible patients are assigned to the experimental or control
arm using a dynamic balanced randomization (1:1) that
incorporates the center and these prespecified factors: age
(⩽70 vs. >70 years), occlusion site (intracranial ICA vs.
MCA-M1 or M1-M2), intravenous fibrinolysis, and lastseen-well
to randomization time (0-4.5 vs. 4.5-23 h).
Intervention
In the experimental arm, MT (started within 60 min postrandomization
and limited to three attempts in a single
vessel) is performed with any approved devices (stentriever
or aspiration).
postrandomization (i.e. NIHSS score increase of ⩾4 points
compared with baseline). Patients in the BMT arm who
undergo secondary MT due to worsening within 24 h postrandomization
are not considered to have crossed over.
They will be included in the BMT arm of both the " per
protocol " and the " as treated " secondary analyses. Clinical
and radiological predictors of clinical deterioration will be
evaluated. The Schedule of the study procedures is
described in Supplementary Table; e 1.
Patient population: Inclusion and exclusion
criteria
All inclusion and exclusion criteria are listed in Table 1.
The main inclusion criteria are ⩾18-year-old patients with
AIS, pre-stroke modified Rankin Scale (mRS) score ⩽ 1,
baseline NIHSS score ⩽ 5, within 23 h of last-seen-well,
ASPECTS score ⩾ 6, and LVO in the anterior circulation
(intracranial internal carotid artery (ICA), M1 or M1-M2
segment of the middle cerebral artery (MCA)) with or without
cervical carotid lesion (tandem occlusion).
WSO December 2023 – Issue 3

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