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regarding its prevalence and predictors.2-7 Indeed, in a
recent meta-analysis, the prevalence of early reocclusion
reached 6.59% with large variation across studies (2.3%-
29.5%) and was associated with a poor functional prognosis.2
This study pointed out that long-term statin and
antiplatelet use might prevent reocclusion while longer
onset-to-reperfusion time seemed to promote reocclusion.
They also found that atrial fibrillation-related stroke is
associated with a lower prevalence of reocclusion.
However, these results are based on few studies hence limiting
their reliability. In this study, we aimed to further
investigate the prevalence, associated factors and influence
on outcomes of reocclusion within 24 h after successful MT
in a large prospective cohort of consecutive stroke patients
with LAO.
Methods
Ethics
The ethical committee (Comité de protection des personnes
Nord-Ouest IV) classified the study as observational on
March 9, 2010, and the committee protecting personal
information of the patient approved the study by 21
December 2010 (n°= 10.677). Anonymized data supporting
the findings of this study are available from the corresponding
author on reasonable request.
Design, setting, and population
Between 1 January 2015 and 1 October 2020, we retrospectively
analyzed all ischemic stroke patients treated by MT
in the Lille reperfusion registry, which is a prospective
observational registry. Details of the study protocol have
been previously reported.8 We reviewed all consecutive
patients treated by MT for an ischemic stroke related to
LAO of the anterior circulation involving either the M1
segment, internal carotid artery terminus or tandem ICAM1
occlusion on cerebral angiography. Patients with an
initial successful recanalization on the final angiogram
(defined as modified Treatment in Cerebral Infarction scale
(mTICI) 2b, 2c or 3)9 were included. Patients without an
available 24-h computed tomography (CT) or magnetic
resonance imaging (MRI) vascular imaging were excluded.
Data collection
Clinical and biological data. Details about the data collected
in the registry database have been previously described.10
When appropriate, MT decision was given on the basis of a
diffusion/fluid-attenuated inversion recovery mismatch
and/or the diffusion/perfusion mismatch.11,12 The cause of
ischemic stroke was determined according to TOAST criteria
(Trial of ORG 10172 in Acute Stroke Treatment classification).13
Clinical severity was assessed using the National
Institutes of Health Stroke Scale (NIHSS) at onset,14 immediately
before reperfusion treatment, 2 h and 24 h after
treatment. Very early clinical improvement, stability, or
worsening were defined as follows: NIHSS at 2 h-NIHSS
pre-MT < 0, 0-4, and >4, respectively.15 Platelets count
and C-reactive protein level were recorded at admission.
Imaging data. Details concerning the first-line imaging
upon admission have been previously described.10 For the
purpose of this study, the last imaging performed before
MT was used to assess radiological data. Patients underwent
follow-up MRI with contrast-enhanced MR angiography
(or CT with CT angiography) 24 h after treatment or
earlier in case of clinical worsening. Early reocclusion was
defined as internal carotid artery terminus or M1 occlusion
on 24 h follow-up vascular imaging or earlier in case of
clinical worsening. We used Alberta Stroke Program Early
CT Score (ASPECTS) to assess the initial and follow-up
extent of ischemic lesion.16 Radiological data were analyzed
by an experienced neuroradiologist blinded to clinical
data.
Angiographic data. Cerebral angiographic images were analyzed
by two experienced interventional neuroradiologists
blinded to clinical and MRI data. The site of occlusion was
classified on pretreatment cerebral angiography into M1
segment, internal carotid artery terminus, or tandem ICAM1
occlusion. Tandem ICA-M1 occlusion was defined as
the coexistence of an internal carotid artery occlusion or
high-grade stenosis (>70%) and an ipsilateral M1 occlusion.
The degree of recanalization after MT was evaluated
using the modified Treatment In Cerebral Infarction scale
(mTICI) on the final angiogram.9 Successful recanalization
was defined as mTICI score 2b or 3. The type of device
(aspiration and/or stent-retrievers) as well as the number of
devices passes were recorded.
Outcome. The primary study outcome was the percentage of
patients who developed an early internal carotid artery terminus
or M1 reocclusion diagnosed on 24 h follow-up imaging
or earlier, in case of clinical worsening. Secondary
outcomes included 90-day functional disabilities (defined as
a mRS score >2 or higher than the prestroke mRS score),
90-day mortality as well as radiological outcomes: infarct
growth (defined as follows: ASPECTS at 24 h-ASPECTS at
admission) and symptomatic intracranial hemorrhage (ICH)
at 24 h after treatment, according to ECASS-2 criteria.17
Statistical analysis
Continuous variables were expressed as mean (standard
deviation (SD)) or as median (interquartile range (IQR)).
Normality of distributions was checked by histograms
inspection and Shapiro-Wilk test. Categorical variables
were expressed as number (percentage). Associated factors
International Journal of Stroke, 18(6)
WSO - July 2023

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