During the coronavirus disease 2019 (COVID-19) pandemic, the World Health Organization recommended measures to mitigate the outbreak such as social distancing and confinement. Since these measures have been put in place, anecdotal reports describe a decrease in the number of endovascular therapy (EVT) treatments for acute ischemic stroke due to large vessel occlusion. The purpose of our study was to determine the effect on EVT for patients with acute ischemic stroke during the COVID-19 confinement. In this retrospective, observational study, data were collected from November 1, 2019, to April 15, 2020, at 17 stroke centers in countries where confinement measures have been in place since March 2020 for the COVID-19 pandemic (Switzerland, Italy, France, Spain, Portugal, Germany, Canada, and United States). This study included 1600 patients treated by EVT for acute ischemic stroke. Date of EVT and symptom onset-to-groin puncture time were collected. Mean number of EVTs performed per hospital per 2-week interval and mean stroke onset-to-groin puncture time were calculated before confinement measures and after confinement measures. Distributions (non-normal) between the 2 groups (before COVID-19 confinement versus after COVID-19 confinement) were compared using 2-sample Wilcoxon rank-sum test. The results show a significant decrease in mean number of EVTs performed per hospital per 2-week interval between before COVID-19 confinement (9.0 [95% CI, 7.8–10.1]) and after COVID-19 confinement (6.1 [95% CI, 4.5–7.7]), ( P <0.001). In addition, there is a significant increase in mean stroke onset-to-groin puncture time ( P <0.001), between before COVID-19 confinement (300.3 minutes [95% CI, 285.3–315.4]) and after COVID-19 confinement (354.5 minutes [95% CI, 316.2–392.7]). Our preliminary analysis indicates a 32% reduction in EVT procedures and an estimated 54-minute increase in symptom onset-to-groin puncture time after confinement measures for COVID-19 pandemic were put into place.

BACKGROUND: The relative value of computed tomography (CT) and magnetic resonance imaging (MRI) in acute ischemic stroke (AIS) is debated. In May 2018, our center transitioned from using CT to MRI as first-line imaging for AIS. This retrospective study aims to assess the effects of this paradigm change on diagnosis and disability outcomes. METHODS: We compared all consecutive patients with confirmed diagnosis of AIS admitted to our center during the MRI-period (May 2018–August 2022) and an identical number of patients from the preceding CT-period (December 2012–April 2018). Univariable and multivariable analyses were performed to evaluate outcomes, including the number and delay of imaging exams, the rate of missed strokes, stroke mimics treated with thrombolysis, undetermined stroke mechanisms, length of hospitalization, and 3-month disability. RESULTS: The median age of the 2972 included patients was 76 years (interquartile range, 65–84), and 46% were female. In the MRI-period, 80% underwent MRI as first acute imaging. The proportion of patients requiring a second acute imaging modality for diagnostic ± revascularization reasons increased from 2.1% to 5% ( P _unadj <0.05), but it decreased in the subacute phase from 79.0% to 60.1% ( P _adj <0.05). In thrombolysis candidates, there was a 2-minute increase in door-to-imaging delay ( P _adj <0.05). The rates of initially missed AIS diagnosis was similar (3.8% versus 4.4%, P _adj =0.32) and thrombolysis in stroke mimics decreased by half (8.6% versus 4.3%; P _adj <0.05). Rates of unidentified stroke mechanism at hospital discharge were similar (22.8% versus 28.1%; P _adj =0.99). The length of hospitalization decreased from 9 (interquartile range, 6–14) to 7 (interquartile range, 4–12) days ( P _adj =0.62). Disability at 3 months was similar (common adjusted odds ratio for favorable Rankin shift, 0.98 [95% CI, 0.71–1.36]; P _adj =0.91), as well as mortality and symptomatic intracranial hemorrhage. CONCLUSIONS: A paradigm shift from CT to MRI as first-line imaging for AIS seems feasible in a comprehensive stroke center, with a minimally increased delay to imaging in thrombolysis candidates. MRI was associated with reduced thrombolysis rates of stroke mimics and subacute neuroimaging needs.

Coronavirus disease 2019 (COVID-19) is associated with an increased risk of thrombotic events. Ischemic stroke in COVID-19 patients entails high severity and mortality rates. Here we aimed to analyze cerebral thrombi of COVID-19 patients with large vessel occlusion (LVO) acute ischemic stroke to expose molecular evidence for SARS-CoV-2 in the thrombus and to unravel any peculiar immune-thrombotic features. We conducted a systematic pathological analysis of cerebral thrombi retrieved by endovascular thrombectomy in patients with LVO stroke infected with COVID-19 (n = 7 patients) and non-covid LVO controls (n = 23). In thrombi of COVID-19 patients, the SARS-CoV-2 docking receptor ACE2 was mainly expressed in monocytes/macrophages and showed higher expression levels compared to controls. Using polymerase chain reaction and sequencing, we detected SARS-CoV-2 Clade20A, in the thrombus of one COVID-19 patient. Comparing thrombus composition of COVID-19 and control patients, we noted no overt differences in terms of red blood cells, fibrin, neutrophil extracellular traps (NETs), von Willebrand Factor (vWF), platelets and complement complex C5b-9. However, thrombi of COVID-19 patients showed increased neutrophil density (MPO⁺ cells) and a three-fold higher Neutrophil-to-Lymphocyte Ratio (tNLR). In the ROC analysis both neutrophils and tNLR had a good discriminative ability to differentiate thrombi of COVID-19 patients from controls. In summary, cerebral thrombi of COVID-19 patients can harbor SARS-CoV2 and are characterized by an increased neutrophil number and tNLR and higher ACE2 expression. These findings suggest neutrophils as the possible culprit in COVID-19-related thrombosis. Graphical Abstract

Background: Whether bridging therapy (intravenous thrombolysis [IVT] followed by mechanical thrombectomy) is superior to IVT alone in minor stroke with large vessel occlusion is unknown. Perfusion imaging may identify subsets of large vessel occlusion–related minor stroke patients with distinct response to bridging therapy. Methods: We conducted a multicenter international observational study of consecutive IVT-treated patients with minor stroke (National Institutes of Health Stroke Scale score ≤5) who had an anterior circulation large vessel occlusion and perfusion imaging performed before IVT, with a subset undergoing immediate thrombectomy. Propensity score with inverse probability of treatment weighting was used to account for baseline between-groups differences. The primary outcome was 3-month modified Rankin Scale score 0 to 1. We searched for an interaction between treatment group and mismatch volume (critical hypoperfusion–core volume). Results: Overall, 569 patients were included (172 and 397 in the bridging therapy and IVT groups, respectively). After propensity-score weighting, the distribution of baseline variables was similar across the 2 groups. In the entire population, bridging was associated with lower odds of achieving modified Rankin Scale score 0 to 1: odds ratio, 0.73 [95% CI, 0.55–0.96]; P =0.03. However, mismatch volume modified the effect of bridging on clinical outcome ( P _interaction =0.04 for continuous mismatch volume); bridging was associated with worse outcome in patients with, but not in those without, mismatch volume <40 mL (odds ratio, [95% CI] for modified Rankin Scale score 0–1: 0.48 [0.33–0.71] versus 1.14 [0.76–1.71], respectively). Bridging was associated with higher incidence of symptomatic intracranial hemorrhage in the entire population, but this effect was present in the small mismatch subset only ( P _interaction =0.002). Conclusions: In our population of large vessel occlusion-related minor stroke patients, bridging therapy was associated with lower rates of good outcome as compared with IVT alone. However, mismatch volume was a strong modifier of the effect of bridging therapy over IVT alone, notably with worse outcome with bridging therapy in patients with mismatch volume ≤40 mL. Randomized trials should consider adding perfusion imaging for patient selection.

Background: Little is known on the role of mismatch profile in patients undergoing early endovascular treatment (EVT). We aimed to describe pretreatment perfusion parameters and mismatch profiles in anterior circulation large vessel occlusion acute ischemic stroke undergoing EVT in the early time window and assess their association with time from stroke onset and outcomes. Methods: Retrospective single-center study, including early (2, symptomatic intracranial hemorrhage, and mortality (multivariate regression analyses [each parameter/profile entered into a separate logistic regression model, adjusted for baseline variables associated with each outcome in the univariate analysis at the P <0.1 level]). Results: Among 357 patients, unfavorable mismatch profiles ranged from 21% to 60%, depending on the criterion, and were not correlated with time from stroke onset ( P =0.490). All individual perfusion parameters and unfavorable mismatch profiles were associated with poor functional outcome: ischemic core volume adjusted odds ratio (aOR), 1.49 ([95% CI, 1.13–1.97] P =0.005); penumbral volume aOR, 0.30 ([95% CI, 0.10–0.84] P =0.022); mismatch ratio aOR, 0.67 ([95% CI, 0.50–0.90] P =0.007); EXTEND-IA aOR, 2.61 ([95% CI, 1.23–5.51] P =0.012); SWIFT PRIME aOR, 2.50 ([95% CI, 1.30–4.57] P =0.006); DEFUSE 3 aOR, 2.28 ([95% CI, 1.14–4.57] P =0.020); and DAWN aOR, 4.19 ([95% CI, 2.13–8.26] P <0.001). EXTEND-IA and DEFUSE 3 unfavorable profiles were also independently associated with symptomatic intracranial hemorrhage (aOR, 3.82 [95% CI, 1.42–10.3]; P =0.008 and aOR, 2.83 [95% CI, 1.09–7.36]; P =0.033) and death (aOR, 3.26 [95% CI, 1.33–8.02]; P =0.010 and aOR, 2.52 [95% CI, 1.10–5.82]; P =0.030). Conclusions: Pretreatment perfusion parameters and mismatch profiles in early EVT-treated patients were not correlated with time from stroke onset but were independently associated with functional outcome. Mismatch assessment in the early time window may improve EVT patient selection, independently of onset-to-treatment time.

Background and purpose If patients presenting with large vessel occlusions (LVO) and mild symptoms should be treated with endvoascular treatment (EVT) remains unclear. Aims of this study were (1) assessing the safety and technical efficacy of EVT in patients with NIHSS < 8 as opposed to a comparison group of patients presenting with NIHSS ≥ 8 and (2) evaluation of the clinical effect of reperfusion in patients with NIHSS < 8. Methods Patients included into the retrospective multicenter BEYOND-SWIFT registry (NCT03496064) were analyzed. Clinical effect of achieving successful reperfusion (defined as modified Thrombolysis in Cerebral Infarction grade 2b/3) in patients presenting with NIHSS < 8 (N = 193) was evaluated using multivariable logistic regression analyses (displayed as adjusted Odds Ratios, aOR and 95% confidence intervals, 95%-CI). Primary outcome was excellent functional outcome (modified Rankin Scale, mRS 0–1) at day 90. Safety and efficacy of mechanical thrombectomy in patients with NIHSS < 8 was compared to patients presenting with NIHSS ≥ 8 (N = 1423). Results Among patients with NIHSS < 8 (N = 193, 77/193, 39.9% receiving pre-interventional IV-tPA), successful reperfusion was significantly related to mRS 0–1 (aOR 3.217, 95%-CI 1.174–8.816) and reduced the chances of non-hemorrhagic neurological worsening (aOR 0.194, 95%-CI 0.050–0.756) after adjusting for prespecified confounders. In interaction analyses, the relative merits of achieving successful reperfusion were mostly comparable between patients presenting with NIHSS < 8 and NIHSS ≥ 8 as evidenced by non-significantly different aOR. Interventional safety and efficacy metrics were similar between patients with NIHSS < 8 and NIHSS ≥ 8. Conclusions Achieving successful reperfusion is beneficial in patients with persisting LVO presenting with NIHSS < 8 and reduces the risk of non-hemorrhagic neurological worsening.