Background: The COVID-19 pandemic led to profound changes in the organization of health care systems worldwide. Aims: We sought to measure the global impact of the COVID-19 pandemic on the volumes for mechanical thrombectomy, stroke, and intracranial hemorrhage hospitalizations over a three-month period at the height of the pandemic (1 March–31 May 2020) compared with two control three-month periods (immediately preceding and one year prior). Methods: Retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The diagnoses were identified by their ICD-10 codes and/or classifications in stroke databases at participating centers. Results: The hospitalization volumes for any stroke, intracranial hemorrhage, and mechanical thrombectomy were 26,699, 4002, and 5191 in the three months immediately before versus 21,576, 3540, and 4533 during the first three pandemic months, representing declines of 19.2% (95%CI, −19.7 to −18.7), 11.5% (95%CI, −12.6 to −10.6), and 12.7% (95%CI, −13.6 to −11.8), respectively. The decreases were noted across centers with high, mid, and low COVID-19 hospitalization burden, and also across high, mid, and low volume stroke/mechanical thrombectomy centers. High-volume COVID-19 centers (−20.5%) had greater declines in mechanical thrombectomy volumes than mid- (−10.1%) and low-volume (−8.7%) centers (p < 0.0001). There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions. Conclusion: The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, mechanical thrombectomy procedures, and intracranial hemorrhage admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke/mechanical thrombectomy volumes.

Objective To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods. Methods We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. Results There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] −11.7 to −11.3, p < 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI −13.8 to −12.7, p < 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI −13.7 to −10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2–9.8, p < 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions. Conclusions The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months.

A narrative review of the pathophysiology of ischemic stroke in carotid plaques: a distinction versus a compromise between hemodynamic and embolic mechanism Laura Mechtouff, Lucie Rascle, Valentin Crespy, Emmanuelle Canet-Soulas, Norbert Nighoghossian, Antoine Millon

Background: We evaluated the management, outcome and haemorrhagic risk in a cohort of ischaemic stroke patients with mild symptoms treated with intravenous tissue plasminogen activator (tPA) within the first 4.5 h. Methods: We analysed data from a prospective stroke thrombolysis registry. A total of 1,043 patients received tPA between 2010 and 2014 in the 5 stroke units of the RESUVAL stroke network (Rhône Valley, France). Among them, 170 patients had a National Institute of Health Stroke Scale (NIHSS) score ≤4 (minor group: MG) before tPA and 873 patients had a NIHSS score >4. Results: A high rate (77%) of excellent outcome (3-month-modified Rankin Scale score ≤1) was observed in the MG. No symptomatic intracerebral haemorrhage occurred and the rate of any haemorrhagic transformation was 5%. Fifty-four percent of the MG patients had visible arterial occlusion before tPA. Patients of the MG were less likely to be transported by Emergency Medical Services and to be directly admitted to the stroke unit or to imaging. Median delays from onset to admission, from admission to imaging and from onset to tPA were longer in the MG. Conclusion: Our data provided evidence of safety and suggested potential benefit of thrombolysis in patients with NIHSS score ≤4. A majority of these patients exhibited arterial occlusion before thrombolysis. Most often, patients with mild stroke are not given priority in terms of the mode of transport, direct admission to stroke unit and rapid imaging, resulting in an increased delay from onset to thrombolysis. Health system improvements are needed to provide all suspected stroke victims equal access to imaging and treatment on an emergency basis.

The ischemic penumbra is defined as the severely hypoperfused, functionally impaired, at-risk but not yet infarcted tissue that will be progressively recruited into the infarct core. Early reperfusion aims to save the ischemic penumbra by preventing infarct core expansion and is the mainstay of acute ischemic stroke therapy. Intravenous thrombolysis and mechanical thrombectomy for selected patients with large vessel occlusion has been shown to improve functional outcome. Given the varying speed of infarct core progression among individuals, a therapeutic window tailored to each patient has recently been proposed. Recent studies have demonstrated that reperfusion therapies are beneficial in patients with a persistent ischemic penumbra, beyond conventional time windows. As a result, mapping the penumbra has become crucial in emergency settings for guiding personalized therapy. The penumbra was first characterized as an area with a reduced cerebral blood flow, increased oxygen extraction fraction and preserved cerebral metabolic rate of oxygen using positron emission tomography (PET) with radiolabeled O₂. Because this imaging method is not feasible in an acute clinical setting, the magnetic resonance imaging (MRI) mismatch between perfusion-weighted imaging and diffusion-weighted imaging, as well as computed tomography perfusion have been proposed as surrogate markers to identify the penumbra in acute ischemic stroke patients. Transversal studies comparing PET and MRI or using longitudinal assessment of a limited sample of patients have been used to define perfusion thresholds. However, in the era of mechanical thrombectomy, these thresholds are debatable. Using various MRI methods, the original penumbra definition has recently gained a significant interest. The aim of this review is to provide an overview of the evolution of the ischemic penumbra imaging methods, including their respective strengths and limitations, as well as to map the current intellectual structure of the field using bibliometric analysis and explore future directions.

Objective To assess whether interleukin-6 (IL-6) level is a marker of futile reperfusion in patients with acute ischemic stroke (AIS) with large vessel occlusion treated with mechanical thrombectomy (MT). Methods The Cohort of Patients to Identify Biological and Imaging Markers of Cardiovascular Outcomes in Stroke (HIBISCUS-STROKE) includes patients with AIS treated with MT after MRI. We performed a sequential assessment of IL-6 (admission, 6 hours, 24 hours, 48 hours and 3 months from admission). Among patients with successful reperfusion (Thrombolysis in Cerebral Infarction scale 2b/3), reperfusion was considered effective if 3-month modified Rankin Scale (mRS) score was 0 to 2 and futile if 3-month mRS score was 3 to 6. Our model was adjusted for the main confounding variables. Results One hundred sixty-four patients represent the study population. One hundred thirty-three patients had successful reperfusion (81.1%), while in 46 (34.6%), reperfusion was classified as futile. In single-variable analyses, high IL-6 levels at 6, 24, and 48 hours in combination with a higher age, a prestroke mRS score >2, a history of hypertension or diabetes, lack of current smoking, a higher baseline NIH Stroke Scale score, the absence of associated intravenous thrombolysis, an intracranial internal carotid artery or a tandem occlusion, and an increased infarct growth were associated with futile reperfusion. After multivariable analyses, a high IL-6 level at 24 hours (odds ratio 6.15, 95% confidence interval 1.71–22.10) remained associated with futile reperfusion. Conclusions IL-6 is a marker of futile reperfusion in the setting of MT.