Safety of endovascular treatment beyond the 6-h time window in 205 patients

Drugs/agents for the treatment of ischemic stroke: Advances and perspectives

Ischemic stroke (IS) poses a significant threat to global human health and life. In recent decades, we have witnessed unprecedented progresses against IS, including thrombolysis, thrombectomy, and a few medicines that can assist in reopening the blocked brain vessels or serve as standalone treatments for patients who are not eligible for thrombolysis/thrombectomy therapies. However, the narrow time windows of thrombolysis/thrombectomy, coupled with the risk of hemorrhagic transformation, as well as the lack of highly effective and safe medications, continue to present big challenges in the acute treatment and long-term recovery of IS. In the past 3 years, several excellent articles have reviewed pathophysiology of IS and therapeutic medicines for the treatment of IS based on the pathophysiology. Regretfully, there is no comprehensive overview to summarize all categories of anti-IS drugs/agents designed and synthesized based on molecular mechanisms of IS pathophysiology. From medicinal chemistry view of point, this article reviews a multitude of anti-IS drugs/agents, including small molecule compounds, natural products, peptides, and others, which have been developed based on the molecular mechanism of IS pathophysiology, such as excitotoxicity, oxidative/nitrosative stresses, cell death pathways, and neuroinflammation, and so forth. In addition, several emerging medicines and strategies, including nanomedicines, stem cell therapy and noncoding RNAs, which recently appeared for the treatment of IS, are shortly introduced. Finally, the perspectives on the associated challenges and future directions of anti-IS drugs/agents are briefly provided to move the field forward.

Endovascular treatment for wake-up stroke and daytime unwitnessed stroke: A meta-analysis

BACKGROUND

Evidence from sources outside the typical clinical research setting, such as a real-world setting, may complement evidence from randomised controlled trials (RCTs). The aim of the present study was to carry out a meta-analysis of available real-world evidence that focused on the efficacy and safety of endovascular treatment in patients with wake-up stroke (WUS) or daytime unwitnessed stroke (DUS) compared to that in patients treated ≤ 6 h after the onset of an ischemic stroke.

METHODS

Data mining was conducted on 1 May 2021 from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials Cochrane Library. The study reviewed all published that assessed the effect of endovascular treatment in WUS and DUS compared to that received by patients with ischemic stroke. Relevant data were extracted and the narrative was reviewed and analysed. The results were expressed as odds ratios (ORs) with 95% confidence intervals (CIs).

FINDINGS

The meta-analysis showed no significant differences between the two groups in the rates of functional independence (OR, 0.81; 95% CI, 0.65-1.02; P = 0.07), symptomatic intracerebral haemorrhage (OR, 0.86; 95% CI, 0.57-1.30; P = 0.470), and all-cause mortality (OR, 0.92; 95% CI, 0.73-1.16; P = 0.50). There was also no heterogeneity between the trials.

CONCLUSION

The pooled analysis provided evidence to support the use of endovascular treatment in WUS and DUS with favourable perfusion imaging. The meta-analysis confirmed the main findings of RCTs of endovascular treatment in WUS and DUS in a real-world setting and therefore strengthens the validity of this treatment strategy.

Benefits of Endovascular Treatment in Late Window for Acute Ischemic Stroke Selected without CT Perfusion: A Real-World Study

Objective

This study examined the functional outcomes and safety of endovascular treatment (EVT) in acute ischemic stroke (AIS) patients owing to large vessel occlusion of the anterior circulation, presented during a late-time window (6–24 hours after last seen well (LSW)) in a real-world practice.

Methods

This was a retrospective analysis from a bi-center prospective cohort. According to the stroke treatment, patients with continuous Alberta Stroke Plan Early Aspect score (ASPECTS) ≥6 on non-contrast CT (NCCT) and moderate to good collateral state on CT angiography (CTA) were divided into EVT group and standard medical treatment (SMT) group. The primary outcome was the rate of functional independence (90-day mRS ≤2). Safety outcomes were the occurrence of symptomatic intracranial hemorrhage (sICH) and the 90-day mortality.

Results

Among the 288 enrolled patients (53.5% male, median age 64 years), there were 167 patients in the EVT group and 121 in the SMT group. After multivariable adjustments for potential confounders, EVT was associated with functional independence (adjusted OR: 3.052; 95% confidence interval (CI): 1.553–5.997; p = 0.001). In the PSM cohort, 44.2% (42/95) of patients in the EVT group versus 18.9% (18/95) in the SMT group achieved functional independence (OR: 3.39, 95% CI: 1.763–6.517), and there was a significant difference favoring EVT over the SMT in the overall distribution of mRS (OR: 2.170, 95% CI: 1.302–3.618) at 90 days. The rate of sICH did not differ between the EVT and SMT groups (10.5% vs 8.4%, p = 0.804) nor did 90-day mortality (18.9% vs 22.1%, p = 0.719). No interaction was found in p-values with statistical significance in subgroup analysis.

Conclusion

This real-world experience suggests that EVT for late-presenting stroke patients, based on small core on NCCT and moderate to good collaterals on CTA, is associated with better outcomes than SMT alone, with no increase in sICH and 90-day mortality rates.

Efficacy and Safety of Endovascular Treatment for Acute Large-Vessel Ischemic Stroke Beyond 6 h After Symptom Onset: A Meta-Analysis

Background: There is considerable evidence on the benefits of endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) within 6 h after symptom onset. However, uncertainties remain regarding EVT efficacy beyond 6 h after symptom onset. We undertook a meta-analysis to assess the efficacy and safety of EVT in patients with AIS >6 h after symptom onset.

Methods: We searched PubMed, EMBASE, and Chinese Biomedical through July 2019. We included studies involving early (≤6 h) vs. delayed (>6 h) EVT in selected patients with AIS, based on radiological evaluation criteria. Functional independence, successful recanalization, mortality, and symptomatic intracranial hemorrhage (sICH) rates were assessed.

Results: Eight articles, with 3,265 patients who had undergone early EVT and 1,078 patients who had received delayed EVT, were included in the meta-analysis. Patients treated with early EVT showed a similar proportion of functional independence at 90 days [odds ratio (OR) = 1.14, 95% confidence interval (CI) = 0.926–1.397, P = 0.219; I² = 36.2%, P = 0.128] as those treated with delayed EVT. Delayed EVT was also associated with no significant difference in mortality (OR = 1.015, 95% CI = 0.852–1.209; P = 0.871; I² = 0.0%, P = 0.527), successful recanalization (OR = 1.255, 95% CI = 0.923–1.705; P = 0.147; I² = 60.5%, P = 0.009), and sICH (OR = 0.976, 95% CI = 0.737–1.293; P = 0.871; I² = 0.0%, P = 0.742) rates compared with early EVT.

Conclusions: Among selected patients with AIS, delayed EVT showed comparable outcomes in functional independence, recanalization, mortality, and sICH rates compared with early EVT.

Targeting the gasdermin D as a strategy for ischemic stroke therapy

Stroke is a major cause of death and disability worldwide that triggers a variety of neuropathological conditions, leading to the initiation of several pro-inflammatory mediators and neuronal damage. Neuroinflammation has been considered the potential therapeutic target and contributes to the pathology of ischemia and reperfusion. Pyroptosis is an inflammatory form of programmed cell death that plays an important role in immune protection against stroke. Gasdermin D (GSDMD) is the final executor of pyroptosis upon cleavage by caspases-1/4/5/11, followed by canonical and noncanonical inflammasome activation, leading to a series of inflammatory responses. GSDMD N-terminal domain assembles plasma membrane as well as organelle membrane pores to induce cytolysis, thereby triggering cytokine release and inflammatory-related cell death. In our review, we concisely summarized and highlighted the potential role of GSDMD-regulated pyroptosis and the biological characteristic of GSDMD as a therapeutic target in ischemic stroke. A better understanding of the roles of GSDMD may provide a theoretical basis for the design of novel therapeutic interventions for the treatment of ischemic stroke.

Endovascular treatment of acute ischemic stroke due to anterior circulation large vessel occlusion beyond 6 hours: a real-world study in China

Background

We aimed to assess the safety and efficacy of endovascular treatment (EVT) in patients with anterior circulation emergent large vessel occlusion (ELVO) beyond 6 h from symptom onset in a real-world cohort of patients in China.

Methods

We retrospectively examined 305 patients with anterior circulation ELVO treated with EVT. Patients were divided into two groups: treated with known onset within 6 h (n = 238) and beyond 6 h (n = 67). Multivariable logistic regression and ordinal shift analyses were used to evaluate the associations between onset-to-groin puncture time and safety and efficacy outcomes.

Results

Treatment beyond 6 h was not associated with symptomatic intracranial hemorrhage within 48 h (sICH; odds ratio [OR] 2.03, 95% confidence interval [CI] 0.48–8.57, p = 0.334), in-hospital mortality (OR 1.95, 95% CI 0.48–7.91, p = 0.348), successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b or 3; OR 0.73, 95% CI 0.31–1.73, p = 0.470), favorable functional outcome (modified Rankin Scale score 0–2; OR 0.55, 95% CI 0.25–1.23, p = 0.145), and functional improvement (modified Rankin Scale shift by 1-point decrease; common OR 0.80, 95%CI 0.45–1.42, p = 0.450) at 3 months compared with treatment within 6 h. Futher interaction analysis showed that stroke etiology did not modify the associations between onset-to-groin puncture time and outcomes (p > 0.05).

Conclusions

In this real-world study, after careful assessment, EVT beyond 6 h from known stroke onset was safe, effective and had comparable short-term outcomes to EVT within 6 h.

Wake-up stroke: imaging-based diagnosis and recanalization therapy

Wake-up stroke (WUS) is a subgroup of ischemic stroke in which patients show no abnormality before sleep while wake up with neurological deficits. In addition to the uncertain onset, WUS patients have difficulty to receive prompt and effective thrombolytic or reperfusion therapy, leading to relatively poor prognosis. A number of researches have indicated that CT or MRI based thrombolysis and endovascular therapy might have benefits for WUS patients. This review article narratively discusses the pathogenesis, risk factors, imaging-based diagnosis and recanalization treatments of WUS with the purpose of expanding current treatment options for this group of stroke patients and exploring better therapeutic methods. The result showed that multimodal MRI or CT scan might be the best methods for extending the time window of WUS and, therefore, a large proportion of WUS patients could have favorable prognosis.

Endovascular Thrombectomy for Acute Ischemic Stroke Beyond 6 Hours From Onset

Background and Purpose:

To evaluate outcome and safety of endovascular treatment beyond 6 hours of onset of ischemic stroke due to large vessel occlusion in the anterior circulation, in routine clinical practice.

Methods:

From the Italian Registry of Endovascular Thrombectomy, we extracted clinical and outcome data of patients treated for stroke of known onset beyond 6 hours. Additional inclusion criteria were prestroke modified Rankin Scale score ≤2 and ASPECTS score ≥6. Patients were selected on individual basis by a combination of CT perfusion mismatch (difference between total hypoperfusion and infarct core sizes) and CT collateral score. The primary outcome measure was the score on modified Rankin Scale at 90 days. Safety outcomes were 90-day mortality and the occurrence of symptomatic intracranial hemorrhage. Data were compared with those from patients treated within 6 hours.

Results:

Out of 3057 patients, 327 were treated beyond 6 hours. Their mean age was 66.8±14.9 years, the median baseline National Institutes of Health Stroke Scale 16, and the median onset to groin puncture time 430 minutes. The most frequent site of occlusion was middle cerebral artery (45.1%). Functional independence (90-day modified Rankin Scale score, 0–2) was achieved by 41.3% of cases. Symptomatic intracranial hemorrhage occurred in 6.7% of patients, and 3-month case fatality rate was 17.1%. The probability of surviving with modified Rankin Scale score, 0–2 (odds ratio, 0.58 [95% CI, 0.43–0.77]) was significantly lower in patients treated beyond 6 hours as compared with patients treated earlier No differences were found regarding recanalization rates and safety outcomes between patients treated within and beyond 6 hours. There were no differences in outcome between people treated 6-12 hours from onset (278 patients) and those treated 12 to 24 hours from onset (49 patients).

Conclusions:

This real-world study suggests that in patients with large vessel occlusion selected on the basis of CT perfusion and collateral circulation assessment, endovascular treatment beyond 6 hours is feasible and safe with no increase in symptomatic intracranial hemorrhage.

Delayed recanalization after MCAO ameliorates ischemic stroke by inhibiting apoptosis via HGF/c-Met/STAT3/Bcl-2 pathway in rats

The activation of tyrosine kinase receptor c-Met by hepatocyte growth factor (HGF) showed an anti-apoptotic effect in numerous disease models. This study aimed to investigate the neuroprotective mechanism of the HGF/c-Met axis-mediated anti-apoptosis underlying the delayed recanalization in a rat model of middle cerebral artery occlusion (MCAO). Permanent MCAO model (pMCAO) was induced by intravascular filament insertion. Recanalization was induced by withdrawing the filament at 3 days after MCAO (rMCAO). HGF levels in the blood serum and brain tissue expressions of HGF, c-Met, phosphorylated-STAT3 (p-STAT3), STAT3, Bcl-2, Bax, cleaved caspase-3(CC3) were assessed using ELISA and western blot, respectively. To study the mechanism, HGF small interfering ribonucleic acid (siRNA) and c-Met inhibitor, su11274, were administered intracerebroventricularly (i.c.v.) or intranasally, respectively. The concentration of HGF in the serum was increased significantly after MCAO. Brain expression of HGF was increased after MCAO and peaked at 3 days after recanalization. HGF and c-Met were both co-localized with neurons. Compared to rats received permanent MCAO, delayed recanalization after MCAO decreased the infarction volume, inhibited neuronal apoptosis, and improved neurobehavioral function, increased expressions of p-STAT3 and its downstream Bcl-2. Mechanistic studies indicated that HGF siRNA and su11274 reversed the neuroprotection including anti-apoptotic effects provided by delayed recanalization. In conclusion, the delayed recanalization after MCAO increased the expression of HGF in the brain, and reduced the infarction and neuronal apoptosis after MCAO, partly via the activation of the HGF/c-Met/STAT3/Bcl-2 signaling pathway. The delayed recanalization may serve as a therapeutic alternative for a subset of ischemic stroke patients.

Endovascular treatment for ischemic stroke beyond the time window: A meta-analysis

Currently, endovascular treatment has been proven to be effective when conducted within 6 hours of symptom onset. However, when patients have symptoms for more than 6 hours, have a daytime-unwitnessed stroke (DUS) or wake up with a stroke (wake-up stroke, WUS), the safety and efficacy of endovascular treatment need to be further elucidated. Therefore, we performed a systematic review and meta-analysis to compare the clinical outcomes of endovascular treatment in patients with ischemic stroke beyond the time window with that ≤6 hours. PubMed, EMBASE, and Ovid MEDLINE were searched from inception to November 2018. The following outcomes were evaluated by a random-effects model: efficacy outcomes, that is, functional independence and successful recanalization, and safety outcomes, that is, symptomatic intracranial hemorrhage and mortality. Subgroup analyses were also performed to examine whether patient or study characteristics were associated with the outcomes. Nine observational studies, including 5192 patients (1414 patients with extended time windows [ETWs]; 3778 patients ≤6 hours), were eligible for analysis. The overall analysis demonstrated that the functional independence was worse in patients with ETWs vs those ≤6 hours (OR, 0.78; 95% CI, 0.68-0.90, P = .0006). However, subgroup analysis showed that there was no significant difference in functional independence between the two groups when patients were selected for a perfusion mismatch by imaging (OR, 1.00; 95% CI, 0.70-1.43, P = 1.000). Therefore, compared with a window ≤6 hours, endovascular treatment with ETWs for ischemic stroke may not result in poor outcomes when patients are typically selected by perfusion techniques.

Cerebral ischaemia with unknown onset: Outcome after recanalization procedure

BACKGROUND

Stroke of unknown time of onset (UTOS) accounts for one-third of contra-indications for revascularization procedures. With modern neuroimaging techniques it is possible to differentiate the core infarcts and the presence of penumbra.

OBJECTIVE

To evaluate outcomes in patients with UTOS, treated with intravenous (i.v.) recombinant tissue-plasminogen activator (rt-PA), mechanical thrombectomy (MT), or both.

METHOD

We conducted this observational study in patients treated by i.v. rt-PA, MT, or both, selected by a diffusion-weighted image/fluid-attenuated inversion recovery mismatch. We evaluated outcomes with the modified Rankin scale (mRS) at 3 months.

RESULTS

Of 992 consecutive patients (522 women, 52.6%; median age 76 years; median baseline national institutes of health stroke scale [NIHSS] 10), 153 (15.4%) had UTOS, including 101 with wake-up strokes. Compared to other patients, they were more likely to have pre-existing mRS scores >2 (P=0.022), multiple infarcts (P<0.001), middle cerebral artery occlusions (P=0.023), and to undergo MT (P=0.003), and less likely to receive i.v. rt-PA (P<0.001). They had higher NIHSS scores (P<0.001) and longer discovery to treatment initiation times (P<0.001). They were more likely to develop pulmonary (P=0.001) and urinary (P=0.006) infections, and pulmonary embolism (P=0.019), and tended to have a higher mortality rate (P=0.052) within 7 days. After adjustment, there was no association of UTOS with any of these outcome measures anymore.

CONCLUSION

Patients with UTOS have more severe strokes and more comorbidities, but after adjustment, their outcomes did not differ from those of other patients.

IMM-H004 therapy for permanent focal ischemic cerebral injury via CKLF1/CCR4-mediated NLRP3 inflammasome activation

Chemokine-like factor 1 (CKLF1) is a potential target for ischemic stroke therapy. The NOD-like receptor protein 3 (NLRP3) inflammasome has been postulated to mediate inflammatory responses during ischemic/reperfusion (I/R) injury. The compound IMM-H004 is a novel coumarin derivative that can improve cerebral I/R injury. This study aims to investigate the effects of IMM-H004 on ischemia stroke injury and further elucidate the molecular mechanisms. The standard pMCAO model of focal ischemia was used in this paper. Drugs were administered at 6 hours after ischemia, and behavioral assessment, euthanasia, and outcome measures were evaluated at 9 hours after ischemia. The effects of IMM-H004 on ischemic stroke injury were determined using 2,3,5-triphenyltetrazolium chloride (TTC) staining, behavioral tests, enzyme-linked immunosorbent assay (ELISA), and Nissl staining. Immunohistologic staining, immunofluorescence staining, quantitative RT-PCR (qPCR), western blotting, and coimmunoprecipitation (CO-IP) assays were used to elucidate the underlying mechanisms. IMM-H004 treatment provided significant protection against ischemia stroke through a CKLF1-dependent anti-inflammatory pathway in rats. IMM-H004 downregulated the amount of CKLF1 binding with C-C chemokine receptor type 4, further suppressing the activation of NLRP3 inflammasome and the following inflammatory response, ultimately protecting the ischemic brain. This preclinical study established the efficacy of IMM-H004 as a potential therapeutic medicine for permanent cerebral ischemia. These results support further efforts to develop IMM-H004 for human clinical trials in acute cerebral ischemia, particularly for patients who are not suitable for reperfusion therapy.

A New Era of Extended Time Window Acute Stroke Interventions Guided by Imaging

Ischemic stroke is one of the most debilitating and deadliest conditions worldwide. Intravenous t-PA is the current standard treatment within 4 hours after onset of symptoms. Recent randomized controlled trials have demonstrated the efficacy of neurointerventional intra-arterial treatment in acute ischemic stroke. About 20% of acute ischemic stroke are classified as wake-up strokes, which falls out of the conventional treatment time window. New evidence suggests that some patients with longer time from symptom onset (up to 24 hours) may benefit from thrombectomy, probably in part due to variations in collateral circulation among individual patients. Advanced imaging can play a crucial role in identifying patients who could benefit from endovascular intervention presenting within extended treatment time windows. In this article, we review the advanced imaging algorithm for ischemic stroke workup in the multiple studies published to date and summarize the results of the clinical trials for late ischemic stroke that can be clinically useful.

IMM-H004 Protects against Cerebral Ischemia Injury and Cardiopulmonary Complications via CKLF1 Mediated Inflammation Pathway in Adult and Aged Rats

(1) Background: Chemokine-like factor 1 (CKLF1) is a chemokine with potential to be a target for stroke therapy. Compound IMM-H004 is a novel coumarin derivative screened from a CKLF1/C-C chemokine receptor type 4 (CCR4) system and has been reported to improve cerebral ischemia/reperfusion injury. This study aims to investigate the protective effects of IMM-H004 on cerebral ischemia injury and its infectious cardiopulmonary complications in adult and aged rats from the CKLF1 perspective. (2) Methods: The effects of IMM-H004 on the protection was determined by 2,3,5-triphenyltetrazolium chloride (TTC) staining, behavior tests, magnetic resonance imaging (MRI) scans, enzyme-linked immunosorbent assay (ELISA), Nissl staining, histo-pathological examination, and cardiopulmonary function detection. Immunohistological staining, immunofluorescence staining, quantitative real-time PCR (qPCR), and western blotting were used to elucidate the underlying mechanisms. (3) Results: IMM-H004 protects against cerebral ischemia induced brain injury and its cardiopulmonary complications, inhibiting injury, and inflammation through CKLF1-dependent anti-inflammation pathway in adult and aged rats. IMM-H004 downregulates the amount of CKLF1, suppressing the followed inflammatory response, and further protects the damaged organs from ischemic injury. (4) Conclusions: The present study suggested that the protective mechanism of IMM-H004 is dependent on CKLF1, which will lead to excessive inflammatory response in cerebral ischemia. IMM-H004 could also be a therapeutic agent in therapy for ischemic stroke and cardiopulmonary complications in the aged population.

Complete Recanalization May Exert the Most Important Effect on Outcomes of Endovascular Treatment in Acute Ischemic Stroke with Small Infarct Core Beyond 6 Hours

OBJECTIVE

To explore the differences among grades of recanalization on outcomes of endovascular treatment for acute anterior large vessel occlusion with small infarct core beyond the 6-hour time window.

METHODS

Patients beyond the 6-hour time window with Alberta Stroke Program Early Computed Tomography Score >7 were retrospectively enrolled from the endovascular treatment for acute anterior circulation ischemic stroke (ACTUAL) registry. They were divided into 3 groups according to the degree of recanalization: modified treatment in cerebral infarction (mTICI) 0-2a, 2b, and 3. We compared the differences of outcomes among groups on modified Rankin Scale score at 90 days, symptomatic intracerebral hemorrhage within 72 hours, and mortality.

RESULTS

A total of 101 patients were enrolled. Median time from onset to groin puncture was 415 minutes (interquartile range: 387-497 minutes). Favorable functional outcomes were significantly better in patients with successful recanalization than in patients with failed recanalization (mTICI 0-2a, 22.7% [5/22]; mTICI 2b, 48.0% [12/25]; and mTICI 3, 61.1% [33/54]; trend P = 0.01). Complete recanalization (mTICI 3) (odds ratio, 5.34; 95% confidence interval, 1.71-16.66; P = 0.004) was associated with good functional outcome. Mortality was different among groups at 90 days (mTICI 0-2a, 36.4% [8/22]; mTICI 2b, 0, [0/25]; P = 0.001; mTICI 0-2a, 36.4% [8/22]; mTICI 3, 9.3% [5/54]; P = 0.008; and mTICI 2b, 0, [0/25]; mTICI 3, 9.3% [5/54]; P = 0.173). There were no significant differences of symptomatic intracranial hemorrhage among groups (mTICI 0-2a, 22.7% [5/22]; mTICI 2b, 12.0% [3/25]; and mTICI 3, 9.3% [5/54]; P = 0.28).

CONCLUSIONS

For acute anterior circulation stroke patients, who were beyond the 6-hour time window, yet with small ischemic core, complete recanalization following endovascular treatment may play the most important role on clinical outcome.

Baseline Troponin T level in stroke and its association with stress cardiomyopathy

BACKGROUND

Differential diagnosis of elevated high sensitive Troponin T (hsTnT) in acute ischemic stroke includes myocardial infarction (MI) and neurogenic stunned myocardium (NSM). The aim of this study was to identify factors associated with baseline hsTnT levels and MI or NSM in acute ischemic stroke.

METHODS

We studied 204 consecutive patients of the prospective acquired Bern Stroke Database with acute ischemic stroke diagnosed by brain MR. All patient histories and cardiac examinations were reviewed retrospectively. Volumetry of lesions on diffusion and perfusion weighted brain imaging (circular singular value decomposition, Tmax >6sec) was performed. Voxel based analysis was performed to identify brain areas associated with hsTnT elevation. Linear regression analysis was used to identify predictors of baseline hsTnT levels and myocardial infarction.

RESULTS

Elevated hsTnT was observed in 58 of the 204 patients (28.4%). The mean age was 68.3 years in the normal hsTnT group and 69.7 years in the elevated hsTnT group. Creatinine (p<0.001, OR 6.735, 95% CI 58.734-107.423), baseline NIHSS score (p = 0.029, OR 2.207, 95% CI 0.675-12.096), ST segment depression (p = 0.025, OR 2.259, 95% CI 2.419-35.838), and negative T waves in baseline ECG (p = 0.002, OR 3.209, 95% CI 13.007-54.564) were associated with hsTnT elevation, while infarct location and size were not. Coronary angiography was performed in 30 of the 204 patients (14.7%) and myocardial infarction was diagnosed in 7 of them (23.3%). Predictive factors for myocardial infarction could not be identified.

CONCLUSION

Elevated baseline baseline hsTnT was associated with NIHSS, creatinine, ST segment depression and inverted T waves, but not with stroke location or size. None of the factors was helpful to differentiate MI and NSM. Therefore, ancillary investigations such as coronary angiography, cardiac MRI or both may be needed to solve the differential diagnosis.

NCCT and CTA-based imaging protocol for endovascular treatment selection in late presenting or wake-up strokes

Introduction

Recently, the benefit of selecting patients for endovascular treatment (EVT) beyond the 6-hour time window using a tissue-based approach was demonstrated in two randomized trials. The optimal imaging protocol for selecting patients is under debate, and it is still unknown if a simpler and faster protocol may adequately select patients with wake-up stroke (WUS) and late-presenting stroke (LPS) for EVT.

Objective

To compare outcomes of patients submitted to EVT presenting within 6 hours of symptom onset or 6–24 hours after last seen well, selected using non-contrast computed tomography (NCCT) and CT angiography (CTA).

Methods

An observational study was performed, which included consecutive patients with anterior circulation ischemic stroke with large vessel occlusion treated with EVT. Patients presenting within 6 hours were treated if their NIH Stroke Scale (NIHSS) score was ≥6 and Alberta Stroke Program Early CT score (ASPECTS) was ≥6, while patients presenting with WUS or 6–24 hours after last seen well (WUS/LPS) were treated if their NIHSSscore was ≥12 and ASPECTS was ≥7.

Results

249 patients were included, 63 of whom were in the WUS/LPS group. Baseline characteristics were similar between groups, except for longer symptom-recanalization time, lower admission NIHSS (16 vs 17, P=0.038), more frequent tandem occlusions (25.4% vs 11.8%, P=0.010), and large artery atherosclerosis etiology (22.2% vs 11.8%, P=0.043) in the WUS/LPS group. No differences in symptomatic intracranial hemorrhage, peri-procedural complications or mortality were found between groups. Three-month functional independence was similar in both groups (65.1% in WUS/LPS vs 57.0% in ≤6 hours, P=0.259) and no differences were found after adjustment for confounders.

Conclusions

This real-world observational study suggests that EVT may be safe and effective in patients with WUS and LPS selected using clinical-core mismatch (high NIHSS/high ASPECTS in NCCT).

Limitations of Current Near-Infrared Spectroscopy Configuration in Detecting Focal Cerebral Ischemia During Cardiac Surgery: An Observational Case-Series Study

Cerebral oximetry using near-infrared spectroscopy (NIRS) allows for continuous monitoring of cerebral perfusion and immediate treatment of hemodynamic perturbations. In configurations used in current clinical practice, NIRS optodes are placed on the patient`s forehead and cerebral oxygen saturation (ScO₂ ) is determined in bilateral frontal cortical samples. However, focal cerebral ischemic lesions outside of the NIRS field of view may remain undetected. The objective of this observational case-series study was to investigate ScO₂ measurements in patients with acute iatrogenic stroke not located in the frontal cortical region. Adult patients undergoing cardiac surgery with cardiopulmonary bypass or interventional cardiology procedures and suffering stroke in the early postoperative period were identified from the Bernese Stroke Registry and analyzed for their intraoperative ScO₂ values and brain imaging data. Main outcome measures were the ScO₂ values, computed tomography and magnetic resonance imaging findings. In six patients, the infarct areas were localized in the vascular territories of the posterior and/or dorsal middle cerebral arteries. One patient had watershed stroke and another one excellent collaterals resulting in normal cerebral blood volume and only subtle decrease of cerebral blood flow in initially critically perfused watershed brain areas. Intraoperative ScO₂ values were entirely unremarkable or nonindicative for brain damage. Our results indicate that uneventful intraoperative NIRS monitoring does not exclude severe cerebral ischemia due to the limited field of view of commercially available NIRS devices. False negative NIRS may occur as a consequence of stroke localized outside the frontal cortex.

A Meta-Analysis of Observational Evidence for the Use of Endovascular Thrombectomy in Proximal Occlusive Stroke Beyond 6 Hours in Patients with Limited Core Infarct

PURPOSE

The safety and efficacy of endovascular thrombectomy (EVT) for patients with proximal occlusive stroke presenting beyond 6 hours and selected on the basis of favorable neuroimaging remains unclear.

MATERIALS AND METHODS

A systematic search was performed from four electronic databases from their inception to Jan 2017. A meta-analysis of outcomes from studies with patients treated beyond 6 hours was compared to those treated within the established 6 hour therapeutic window in randomized trials, selected using conventional imaging methods with CT/CT angiography.

RESULTS

A total of 8 articles met inclusion criteria for the study population (a prospective single-center study, 5 retrospective single-center studies and 2 retrospective multicenter studies). These were compared to the results of three prospective trials of patients treated within 6 hours selected using CT/CT angiography. For patients treated >6 hours and <6 hours respectively, the weighted mean age was 64.7 vs. 67.0 years; the presenting NIHSS was 15.7 vs. 17.1 and the time from symptom onset to puncture was 4.0 hours vs. 15.1 hours. Weighted pooled estimates of successful recanalization (TIMI 2/3 or TICI 2b/3) and favorable outcome (mRS ≤2) were similar between both groups, 70.1% vs. 70.6%, P=0.75 and 38.9% vs. 38.4%, P=0.88 respectively. Pooled mortality measured at 3 months was 22.8% for those treated >6 hours and 12.5% for <6 hours, P<0.0001. Symptomatic intracranial hemorrhage was not significantly different (10.0% vs. 7.7%, P=0.33).

CONCLUSION

When compared to established methods of patient selection, EVT employed beyond 6 hours in those selected with imaging to exclude large core infarcts achieves similar rates of recanalization, and functional outcome but there is a significant increase in mortality despite no increase in symptomatic intracranial hemorrhage.

Intravenous Thrombolysis in Unknown-Onset Stroke: Results From the Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Registry

BACKGROUND AND PURPOSE

Stroke patients with unknown onset (UKO) are excluded from thrombolytic therapy. We aim to study the safety and efficacy of intravenous alteplase in ischemic stroke patients with UKO of symptoms compared with those treated within 4.5 hours in a large cohort.

METHODS

Data were analyzed from 47 237 patients with acute ischemic stroke receiving intravenous tissue-type plasminogen activator in hospitals participating in the Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Registry between 2010 and 2014. Two groups were defined: (1) patients with UKO (n=502) and (2) patients treated within 4.5 hours of stroke onset (n=44 875). Outcome measures were symptomatic intracerebral hemorrhage per Safe Implementation of Treatment in Stroke on the 22 to 36 hours post-treatment neuroimaging and mortality and functional outcome assessed by the modified Rankin Scale at 3 months.

RESULTS

Patients in UKO group were significantly older, had more severe stroke at baseline, and longer door-to-needle times than patients in the ≤4.5 hours group. Logistic regression showed similar risk of symptomatic intracerebral hemorrhage (adjusted odds ratio, 1.09; 95% confidence interval, 0.44-2.67) and no significant differences in functional independency (modified Rankin Scale score of 0-2; adjusted odds ratio, 0.79; 95% confidence interval, 0.56-1.10), but higher mortality (adjusted odds ratio, 1.58; 95% confidence interval, 1.04-2.41) in the UKO group compared with the ≤4.5 hours group. Patients treated within 4.5 hours showed reduced disability over the entire range of modified Rankin Scale compared with the UKO group (common adjusted odds ratio, 1.29; 95% confidence interval, 1.01-1.65).

CONCLUSIONS

Our data suggest no excess risk of symptomatic intracerebral hemorrhage but increased mortality and reduced favorable outcome in patients with UKO stroke compared with patients treated within the approved time window.

Locked Temporary Vascular Shunt for Wartime Vascular Injuries

INTRODUCTION

To reduce the ischaemia time of injured limbs in wartime, temporary vascular shunts (TVS) are commonly used. However, TVS are stabilized at the ends of the injured vessels using manual suture ties, the risk of dislodgement is high, and tightening manual suture ties is too time consuming.

TECHNICAL SUMMARY

Locked temporary vascular shunts (LTVS) were designed, and each was composed of a silicone tube with a threaded outer surface and smooth inner surface in addition to two nylon buckle switches. The buckle switches were used to stabilize the silicone tube of the LTVS with respect to the vessel walls. This job was performed with two manual suture ties with the current TVS. The mean bursting pressure value of the veins shunted with the LTVS was 114.3% higher than that of the veins shunted with the TVS (0.045 ± 0.008 MPa vs. 0.021 ± 0.012 MPa; p = .00). Although the mean shunting time of the LTVS was reduced by 60.4% compared with that of the TVS (138.89 ± 18.22 seconds vs. 350.48 ± 52.20 seconds; p = .00), there was no significant difference in the patency times between the two types of devices (8.20 ± 9.01 hour vs. 8.40 ± 8.85 hour; p = .98).

CONCLUSION

The LTVS, which was designed to treat wartime vascular injuries, might be safer and more efficient than the current TVS.

Neurological Fallacies Leading to Malpractice: A Case Studies Approach

A young woman presents with an intracranial arachnoid cyst. Another is diagnosed with migraine headache. An elderly man awakens with a stroke. And a baby delivered vaginally after 2 hours of questionable electronic fetal monitoring patterns grows up to have cerebral palsy. These seemingly disparate cases share a common underlying theme: medical myths. Myths that may lead not only to misdiagnosis and treatment harms but to seemingly never-ending medical malpractice lawsuits, potentially culminating in a settlement or judgment against an unsuspecting neurologist. This article provides a case studies approach exposing the fallacies and highlighting proper management of these common neurologic presentations.

Wake-up stroke: Dawn of a new era

Wake-up stroke or stroke with unclear onset of symptoms is known to occur in one-fourth of ischemic stroke patients. These patients are not considered for thrombolytic therapy based on time designation of their symptom onset as per the current guidelines. Observational studies have investigated the pathophysiology and suggested actual onset of symptoms to be approximate to the awakening time for these patients. Use of advanced imaging modalities in these patients tends to identify favorable patient profiles for thrombolysis. Results of the ongoing trials will likely beckon a seminal juncture in stroke therapy and deliver critical modifications in the current treatment guidelines for thrombolysis in this substantial, yet neglected, group of stroke patients. In this article, we have reviewed the predisposing factors, preferred imaging modalities and various ongoing thrombolytic and endovascular trials to date for patients with unclear time of symptom onset or who wake up with stroke symptoms.

What to do With Wake-Up Stroke

Wake-up stroke, defined as the situation where a patient awakens with stroke symptoms that were not present prior to falling asleep, represents roughly 1 in 5 acute ischemic strokes and remains a therapeutic dilemma. Patients with wake-up stroke were excluded from most ischemic stroke treatment trials and are often not eligible for acute reperfusion therapy in clinical practice, leading to poor outcomes. Studies of neuroimaging with standard noncontrast computed tomography (CT), magnetic resonance imaging (MRI), and multimodal perfusion-based CT and MRI suggest wake-up stroke may occur shortly before awakening and may assist in selecting patients for acute reperfusion therapies. Pilot studies of wake-up stroke treatment based on these neuroimaging features are promising but have limited generalizability. Ongoing randomized treatment trials using neuroimaging-based patient selection may identify a subset of patients with wake-up stroke that can safely benefit from acute reperfusion therapies.

Every 15-Min Delay in Recanalization by Intra-Arterial Therapy in Acute Ischemic Stroke Increases Risk of Poor Outcome

Background

Intra-arterial therapy has improved recanalization rates compared with intravenous thrombolysis for acute ischemic stroke; however, superior clinical efficacy has not been convincingly demonstrated. Time to recanalization is postulated as a mechanism hindering the efficacy of intra-arterial therapy.

Aim

To investigate the effects of time to recanalization on clinical outcome postintra-arterial therapy for acute ischemic stroke.

Methods

Clinical data were collected prospectively for consecutive patients undergoing intra-arterial therapy for acute ischemic stroke at a single center between 2009 and 2013. Ninety-day functional outcome was assessed by the modified Rankin scale. Univariate analyses identified candidate clinical variables for inclusion in the multivariable model; multivariable logistic regression analyses identified variables independently associated with good outcome, defined as modified Rankin scale 0–2.

Results

One hundred and seven patients were included in the analysis. Median (interquartile range) age was 67 (54–77) years, 41 (38%) were female, and median (interquartile range) baseline National Institute of Health Stroke Severity score was 18 (13–22). Median time from symptom onset to recanalization was 330 min (interquartile range 277–397). Fifty-four (50%) patients achieved a favorable modified Rankin scale at 90 days. Age, successful recanalization, and time to recanalization were independently associated with good outcome at 90 days in multivariable logistic regression analysis. For every 15 min delay in recanalization, the odds of good outcome decreased by 10%.

Conclusions

Longer time to recanalization was associated with poorer functional outcome post intra-arterial therapy. We recommend that a systematic approach to minimize time delay to treatment is warranted in intra-arterial therapy for acute ischemic stroke.

Endovascular therapy of wake-up strokes in the modern era of stent retriever thrombectomy

Background

Endovascular treatment of wake-up strokes (WUS) has been previously described, mostly with the use of pharmacological thrombolysis or first generation thrombectomy devices.

Objective

To describe outcomes of WUS treated with modern endovascular therapy since the Food and Drug Administration approval of stent retrievers, and to identify predictors of good clinical outcome in this population of stroke patients.

Methods

We performed a multicenter retrospective analysis of consecutive patients with WUS who underwent thrombectomy with stent retrievers Trevo (Stryker, Kalamazoo, Michigan, USA) and Solitaire FR (Covidien, Irvine, California, USA), or primary aspiration thrombectomy. We correlated favorable clinical outcomes with demographic, clinical, and technical characteristics.

Results

52 patients were included in this study; 46 (88%) cases were treated with stent retrievers and 6 (12%) were treated with primary aspiration thrombectomy alone. Successful recanalization (Thrombolysis in Cerebral Infarction (TICI) 2b/3) was achieved in 36 (69%) patients. Favorable clinical outcome at 3 months, defined as a modified Rankin Scale score of 0–2, was achieved in 25 (48%) patients. Duration of intervention <30 min and its success, defined as TICI 2b/3 recanalization, were strong predictors of favorable clinical outcome at 90 days (p<0.001 and p<0.0001, respectively).

Conclusions

Our study indicates that endovascular treatment of WUS with stent retrievers and aspiration thrombectomy is safe and effective.

Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times (ESCAPE) trial: methodology

ESCAPE is a prospective, multicenter, randomized clinical trial that will enroll subjects with the following main inclusion criteria: less than 12 h from symptom onset, age > 18, baseline NIHSS >5, ASPECTS score of >5 and CTA evidence of carotid T/L or M1 segment MCA occlusion, and at least moderate collaterals by CTA. The trial will determine if endovascular treatment will result in higher rates of favorable outcome compared with standard medical therapy alone. Patient populations that are eligible include those receiving IV tPA, tPA ineligible and unwitnessed onset or wake up strokes with 12 h of last seen normal. The primary end-point, based on intention-to-treat criteria is the distribution of modified Rankin Scale scores at 90 days assessed using a proportional odds model. The projected maximum sample size is 500 subjects. Randomization is stratified under a minimization process using age, gender, baseline NIHSS, baseline ASPECTS (8-10 vs. 6-7), IV tPA treatment and occlusion location (ICA vs. MCA) as covariates. The study will have one formal interim analysis after 300 subjects have been accrued. Secondary end-points at 90 days include the following: mRS 0-1; mRS 0-2; Barthel 95-100, EuroQOL and a cognitive battery. Safety outcomes are symptomatic ICH, major bleeding, contrast nephropathy, total radiation dose, malignant MCA infarction, hemicraniectomy and mortality at 90 days.

Stroke unit management and revascularisation in acute ischemic stroke

BACKGROUND

Stroke affects one in six people throughout their lifetimes and is the most frequent cause of disability in adults. Several recanalization therapies have emerged and the management of patients in stroke units has improved over the last decades.

SUMMARY

This article examines the current treatment options for stroke patients, summarizing the key clinical evidence, as well as listing the complications and practical issues related to each of these main treatment options.

KEY MESSAGES

Recent advances in the treatment of acute stroke include developments in intravenous thrombolysis (IVT), intra-arterial treatment and bridging therapies.

CLINICAL IMPLICATIONS

Treatment within a stroke unit reduces mortality and disability regardless of age, sex and stroke severity. IVT is widely available and reduces disability when initiated within 4.5 h after the onset of symptoms. The major limitations of IVT are the low recanalization rates and the narrow time frame. Intra-arterial treatment, especially when using newly developed stent-retrievers, achieves very high recanalization rates. It is restricted by its limited availability and by the longer time span required to initiate therapy. Bridging both therapies is a promising approach that combines the advantages of both therapies, but the superiority of this approach remains to be proven. Future strategies to reduce the burden of acute stroke in Europe should focus on immediate access to acute stroke care and dedicated stroke units for all patients.

Wake-up stroke and stroke of unknown onset: a critical review

Patients, who wake up with an ischemic stroke, account for a large number of the total stroke population, due to circadian morning predominance of stroke. Currently, this subset of patients is excluded from revascularization-therapy since no exact time of onset is known. A large group of these patients might be eligible for therapy. In this review, we assessed the current literature about the hypothesis that wake-up-strokes occur just prior on awakening and if this subgroup differs in characteristics compared to the overall stroke population. We looked at the safety and efficacy of thrombolysis and interventional techniques in the group of patients with unknown stroke-onset. We performed a meta-analysis of the diagnostic accuracy of the diffusion-FLAIR mismatch in identifying stroke within 3 and 4.5 h. The different imaging-selection criteria that can be used to treat these patients are discussed. Additional research on imaging findings associated with recent stroke and penumbral imaging will eventually lead to a shift from a rigid time-frame based therapy to a tissue-based individualized treatment approach.

Capillary Index Score in the Interventional Management of Stroke trials I and II

BACKGROUND AND PURPOSE

The Capillary Index Score (CIS) is a simple angiography-based scale for assessing viable tissue in the ischemic territory. We retrospectively applied it to Interventional Management of Stroke (IMS) trials I and II to evaluate the predictive value for good outcomes.

METHODS

CIS was calculated from pretreatment diagnostic cerebral angiograms blinded to outcome. IMS I and II diagnostic cerebral angiogram images of sufficient quality were reviewed and CIS calculated for treated subjects with internal carotid artery or M1 occlusion. CIS scoring (0-3) was dichotomized into favorable (f CIS; 2 or 3) and poor (p CIS; 0 or 1). Modified thrombolysis in cerebral infarction score 2b or 3 was considered good revascularization. CIS and modified thrombolysis in cerebral infarction scores were compared with good outcome, defined as modified Rankin Scale score≤2 at 90 days.

RESULTS

Twenty-eight of 161 subjects met the inclusion criteria. Thirteen (46%) had f CIS. Good clinical outcome was significantly different between the 2 CIS groups (62% for f CIS versus 7% for p CIS; P=0.004). Good reperfusion correlated to good outcome (P=0.04). No significant differences in time to intravenous or intra-arterial treatment were identified between f CIS and p CIS groups (P>0.25).

CONCLUSIONS

A f CIS was found in ≈50% of subjects and was a virtual prerequisite for good outcome in this study subgroup of IMS I and II. We call this the 50% barrier.

Safety and effectiveness of endovascular treatment of stroke with unknown time of onset

BACKGROUND

Currently, treatment options for patients with strokes with unknown time of onset (UKO) remain limited. With the advance of neuroimaging and endovascular treatment (EVT), selected patients might have a chance of a therapeutic option. We sought to compare clinical outcome after EVT in patients with known time of stroke onset (KO) and in those with UKO.

METHODS

We prospectively registered consecutive patients with acute large artery occlusion of the anterior territory who underwent EVT. Multimodal MR or Alberta Stroke Program early CT score (ASPECTS) and transcranial color-coded Duplex sonography were used to select patients for EVT. Recanalization, periprocedural complications, intracranial hemorrhage (ICH) and outcome were recorded. Symptomatic ICH (sICH) was defined as a worsening of ≥4 points in the National Institutes of Health Stroke Scale (NIHSS) score within 36 h in any bleeding. Favorable outcome was defined as a modified Rankin score ≤2 at 3 months.

RESULTS

A total of 141 patients were studied, 109 with KO and 32 with UKO. Mean age was 66.5 versus 64.7 years (p = 0.005) and median baseline NIHSS was 18 versus 17 (p = 0.095), respectively. Prior IV tPA was more frequently administered to KO patients (62.4 vs. 9.4%, p < 0.001), whereas patient selection using multimodal MR was more frequent in patients with UKO (78.1 vs. 45.4%, p < 0.001). Median time from stroke onset or from the last time the patient was seen well to groin puncture and to recanalization was significantly longer in patients with UKO, but no differences were found in the duration of the procedure. For KO/UKO patients recanalization was seen in 77.1 vs. 65.7% (p = 0.084), sICH occurred in 10 versus 0% (p = 0.061) and favorable outcome at 3 months was achieved in 41.3 versus 50% (p = 0.382), respectively.

CONCLUSIONS

Clinical outcomes in this series of EVT in ischemic stroke patients due to large anterior arterial occlusion with salvageable brain are similar for patients treated with KO and UKO. These data support a randomized study of EVT in extended or uncertain time windows..

Outcome of standard and high-risk patients with acute anterior circulation stroke after stent retriever thrombectomy

BACKGROUND AND PURPOSE

Stent retrievers have become an important tool for the treatment of acute ischemic stroke. The aim of this study was to analyze outcome and complications in a large cohort of patients with stroke treated with the Solitaire stent retriever. The study also included patients who did not meet standard inclusion criteria for endovascular treatment: low or high baseline National Institutes of Health Stroke Scale score, ≥80 years of age, extensive ischemic signs in middle cerebral artery territory, and time from symptom onset to endovascular intervention>8 hours.

METHODS

Consecutive patients with acute anterior circulation stroke treated with the Solitaire FR were analyzed. Data on characteristics of endovascular interventions, complications, and clinical outcome were collected prospectively. Patients who met standard inclusion criteria were compared with those who did not.

RESULTS

A total of 227 patients were included. Mean age was 68.2±14.7 years, and median National Institutes of Health Stroke Scale score on admission was 16 (range, 2-36). Reperfusion was successful (thrombolysis in cerebral infarction, 2b-3) in 70.9%. Outcome was favorable (modified Rankin Scale, 0-2) in 57.7% of patients who met standard inclusion criteria and 30.3% of those who did not. The rates for symptomatic intracranial hemorrhage were 3.7% and 13.1%, for death 11.4% and 33.8%, and for symptomatic intraprocedural complications 2.5% and 4.8%, respectively.

CONCLUSIONS

Patients<80 years of age, without extensive pretreatment ischemic signs, and baseline National Institutes of Health Stroke Scale score≤30 had high rates of favorable outcome and low periprocedural complication rates after Solitaire thrombectomy. Successful reperfusion was also common in patients not fulfilling standard inclusion criteria, but worse clinical outcomes warrant further research with a special focus on optimal patient selection.