Intracranial Bleeding After Reperfusion Therapy in Acute Ischemic Stroke

Association of Admission Hyperglycemia with Clinical Outcomes in Patients with Symptomatic Intracranial Hemorrhage After Endovascular Treatment for Large Vessel Occlusive Stroke

Background

Symptomatic intracranial hemorrhage (sICH) is a fatal complication after endovascular treatment (EVT) for acute large vessel occlusive (LVO) stroke. The aim of this study was to investigate the association between hyperglycemia and outcomes in patients with postprocedural sICH.

Methods

Of the 2567 patients with AIS who underwent EVT from two large multicenter randomized trials and two prospective multicenter registry studies, 324 patients occurred sICH with documented admission glucose were included in this study. The primary outcome was functional independence (defined as a modified Rankin Scale score of 0 to 2) at 90 days. Secondary outcomes included mRS score of 0 to 3, 0 to 1, and mRS score at 90 days. Safety outcome was the mortality within 90 days. Admission hyperglycemia was defined as a plasma blood glucose ≥7.8 mmol/L (140 mg/dL) in our analysis.

Results

Of 324 eligible participants included in this study, hyperglycemia was observed in 130 (40.1%) patients. The median age was 67 (IQR, 58-75) years, and median blood glucose level was 7.1 (IQR, 6.0-9.3) mmol/L. After adjusting for confounding variables, admission hyperglycemia was associated with decreased odds of functional independence (adjusted odds ratio[OR] 0.34; 95% CI 0.17-0.68; P= 0.003), decreased odds of favorable outcome (adjusted OR 0.31; 95% CI 0.16-0.58; P < 0.001) and increased odds of mortality (adjusted OR 2.56; 95% CI 1.47-4.45; P = 0.001) at 90 days. After 1:1 propensity score matching analysis, the results were consistent with multivariable logistic regression analysis.

Conclusion

In patients who suffered sICH after EVT for acute large vessel occlusive stroke, hyperglycemia is a strong predictor of poor clinical outcome and mortality at 90 days.

Detection of lipid radicals generated via cerebral ischemia/reperfusion injury using a radiolabeled nitroxide probe

Reactive oxygen species generated via reperfusion cause lipid damage and induce lipid peroxidation, leading to cerebral ischemia/reperfusion injury and exacerbation of cerebral infarction. Lipid radicals are key molecules generated during lipid peroxidation. Therefore, understanding the spatiotemporal behavior of lipid radicals is important to improve the therapeutic outcomes of cerebral infarction. However, the behaviors of lipid radicals in the brain remain unclear. In this study, we aimed to evaluate the distribution of radioactivity in a transient middle cerebral artery occlusion (tMCAO) model using lipid radical detection probe [125I]1 to assess the behaviors of lipid radicals after cerebral ischemia/reperfusion. The tMCAO model administered [125I]1 exhibited significant differences in the timing and location of radioactivity accumulation between the ischemic and non-ischemic regions. Liquid chromatography/mass spectrometry analysis identified the lipid radical adducts formed by the reaction of 1 with the lipid radicals generated after reperfusion. More adducts were detected in the ischemic region samples than in the non-ischemic region samples. Therefore, 1 successfully detected the lipid radicals generated after cerebral ischemia/reperfusion. Overall, this study demonstrates the potential of nuclear medical imaging using radiolabeled 1 to detect the lipid radicals generated after cerebral ischemia/reperfusion. Our approach can aid in the development of new therapeutic agents scavenging lipid radicals after cerebral reperfusion by facilitating the determination of therapeutic efficacy and optimal administration period.

Fgf17: A regulator of the mid/hind brain boundary in mammals

The Fibroblast growth factor (FGFs) family consists of at least 22 members that exert their function by binding and activating fibroblast growth factor receptors (FGFRs). The Fgf8/FgfD subfamily member, Fgf17, is located on human chromosome 8p21.3 and mouse chromosome 14 D2. In humans, FGF17 can be alternatively spliced to produce two isoforms (FGF17a and b) whereas three isoforms are present in mice (Fgf17a, b, and c), however, only Fgf17a and Fgf17b produce functional proteins. Fgf17 is a secreted protein with a cleavable N-terminal signal peptide and contains two binding domains, namely a conserved core region and a heparin binding site. Fgf17 mRNA is expressed in a wide range of different tissues during development, including the rostral patterning centre, midbrain-hindbrain boundary, tailbud mesoderm, olfactory placode, mammary glands, and smooth muscle precursors of major arteries. Given its broad expression pattern during development, it is surprising that adult Fgf17-/- mice displayed a rather mild phenotype; such that mutants only exhibited morphological changes in the frontal cortex and mid/hind brain boundary and changes in certain social behaviours. In humans, FGF17 mutations are implicated in several diseases, including Congenital Hypogonadotropic Hypogonadism and Kallmann Syndrome. FGF17 mutations contribute to CHH/KS in 1.1% of affected individuals, often presenting in conjunction with mutations in other FGF pathway genes like FGFR1 and FLRT3. FGF17 mutations were also identified in patients diagnosed with Dandy-Walker malformation and Pituitary Stalk Interruption Syndrome, however, it remains unclear how FGF17 is implicated in these diseases. Altered FGF17 expression has been observed in several cancers, including prostate cancer, hematopoietic cancers (acute myeloid leukemia and acute lymphoblastic leukemia), glioblastomas, perineural invasion in cervical cancer, and renal cell carcinomas. Furthermore, FGF17 has demonstrated neuroprotective effects, particularly during ischemic stroke, and has been shown to improve cognitive function in ageing mice.

Association between ASPECTS region of infarction and clinical outcome in non-acute large vessel occlusion ischaemic stroke after endovascular recanalisation

PURPOSE

This study retrospectively investigated whether infarction in specific Alberta Stroke Program Early CT Score (ASPECTS) regions is associated with clinical outcome in patients with symptomatic non-acute internal carotid or middle cerebral artery occlusion who underwent endovascular recanalisation (ER).

METHODS

Preoperative ASPECTS and region of infarction were recorded before recanalisation. Clinical outcome was evaluated 90 days after the procedure using the modified Rankin Scale; a score>2 was defined as poor outcome. Secondary outcomes included postprocedural cerebral oedema, intracranial haemorrhage (ICH) and symptomatic ICH.

RESULTS

Among the 86 patients included, 90-day outcome was poor in 30 (34.9%) and 40 experienced cerebral oedema (46.5%). Multivariate logistic regression models showed that lenticular nucleus infarction (OR 19.61-26.00, p<0.05), admission diastolic blood pressure (OR 1.07-1.08, p<0.05), preprocedural National Institutes of Health Stroke Scale (OR 1.96-2.05, p<0.001) and haemorrhagic transformation (OR 14.99-18.81, p<0.05) were independent predictors of poor 90-day outcome. The area under the receiver operating characteristic curve for lenticular nucleus infarction as a predictor of poor outcome was 0.73. M2 region infarction (OR 26.07, p<0.001) and low American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology collateral circulation grade (OR 0.16, p=0.001) were independent predictors of postprocedural cerebral oedema. The area under the receiver operating characteristic curve for M2 region infarction as a predictor of cerebral oedema was 0.64. Region of infarction did not significantly differ between patients with and without postprocedural ICH or symptomatic ICH.

CONCLUSIONS

Lenticular nucleus and M2 region infarction were independent predictors of poor 90-day outcome and postprocedural cerebral oedema, respectively, in patients with non-acute anterior circulation large artery occlusion who underwent ER.

Post-Thrombectomy Subarachnoid Hemorrhage: Incidence, Predictors, Clinical Relevance, and Effect Modulators

BACKGROUND

Subarachnoid hemorrhage (SAH) following endovascular thrombectomy (EVT) is a poorly understood phenomenon, and whether it is associated with clinical detriment is unclear.

METHODS

This was an explorative analysis of a national database of real-world hospitalizations in the United States. Patients who underwent EVT were included. Patients were divided into SAH and non-SAH groups, and hospitalization outcomes were compared using multivariable logistic regression models. Regression models were also used to identify significant predictors for post-EVT SAH, and significant modulators of SAH's association with hospitalization outcomes were also assessed.

RESULTS

A total of 99,219 EVT patients were identified; 6174 (6.2%) had SAH. Overall, SAH was independently associated with increased odds of in-hospital mortality (21.5% vs. 10.6%, adjusted OR 2.53 [95%CI 2.23-2.87], p < 0.001) and lower odds of routine discharge to home with self-care (18.2% vs. 28.0%, aOR 0.58 [95%CI 0.52-0.65], p < 0.001). Distal/medium vessel occlusion (DMVO), coagulopathy, angioplasty or stenting, concurrent intraparenchymal hemorrhage (IPH), and female sex were associated with higher odds of SAH. DMVO was associated with particularly heightened risk of death (31.8% vs. 7.9%, aOR 6.99 [95%CI 2.99 to 16.3], p < 0.001), which was an effect size significantly larger than other sites of vascular occlusion (interaction p > 0.05).

CONCLUSION

SAH is an uncommon but likely clinically detrimental post-EVT complication. DMVO, coagulopathy, angioplasty or stenting, concurrent IPH, and female sex were independently associated with higher odds of post-EVT SAH. SAH associated with DMVO-EVT may be particularly harmful.

Clopidogrel Hyperresponsiveness and Hemorrhagic Complications Using On-Label Clopidogrel Dosing after Pipeline Embolization

Introduction: Clopidogrel hyperresponsiveness is a timely topic, with wide ranging reports of hemorrhagic complications, using various clopidogrel dosing strategies following neuroendovascular procedures. This study serves to investigate hemorrhagic complications using standard clopidogrel doses and timing of these complications in relation to the procedure. Materials and Methods: Retrospective cohort of consecutive adult patients undergoing flow diversion with Pipeline Embolization Device (PED) at an academic medical center, receiving on-label clopidogrel doses. Patients with clopidogrel hyperresponsiveness (VerifyNowTM P2Y12 reaction unit (PRU) ≤ 70) were compared to those who were normoresponsive. The primary outcome is the rate of hemorrhagic complications between groups. Results: Of 148 included patients, 54 (36.5%) were identified as clopidogrel hyperresponsive (PRU ≤ 70) and 94 (63.5%) as clopidogrel normoresponsive (PRU 71 - 194). There were no hemorrhagic complications observed in patients who were clopidogrel hyperresponsive, with 5 occurring in patients who were normoresponsive (P = 0.09). Three (60%) of the hemorrhages were intracranial with most occurring intra-procedure or within the first week of the procedure. Age > 60 years was the only candidate predictor for hemorrhagic complications (P = 0.004). Conclusion: Our findings are contradictory, with lower hemorrhagic complications in clopidogrel hyperresponders than prior literature, and most occurring intra-op or in the immediate acute post-op phase.

Circulating miRNA profiles and the risk of hemorrhagic transformation after thrombolytic treatment of acute ischemic stroke: a pilot study

Background

Hemorrhagic transformation (HT) in acute ischemic stroke is likely to occur in patients treated with intravenous thrombolysis (IVT) and may lead to neurological deterioration and symptomatic intracranial hemorrhage (sICH). Despite the complex inclusion and exclusion criteria for IVT and some useful tools to stratify HT risk, sICH still occurs in approximately 6% of patients because some of the risk factors for this complication remain unknown.

Objective

This study aimed to explore whether there are any differences in circulating microRNA (miRNA) profiles between patients who develop HT after thrombolysis and those who do not.

Methods

Using qPCR, we quantified the expression of 84 miRNAs in plasma samples collected prior to thrombolytic treatment from 10 individuals who eventually developed HT and 10 patients who did not. For miRNAs that were downregulated (fold change (FC) <0.67) or upregulated (FC >1.5) with p < 0.10, we investigated the tissue specificity and performed KEGG pathway annotation using bioinformatics tools. Owing to the small patient sample size, instead of multivariate analysis with all major known HT risk factors, we matched the results with the admission NIHSS scores only.

Results

We observed trends towards downregulation of miR-1-3p, miR-133a-3p, miR-133b and miR-376c-3p, and upregulation of miR-7-5p, miR-17-3p, and miR-296-5p. Previously, the upregulated miR-7-5p was found to be highly expressed in the brain, whereas miR-1, miR-133a-3p and miR-133b appeared to be specific to the muscles and myocardium.

Conclusion

miRNA profiles tend to differ between patients who develop HT and those who do not, suggesting that miRNA profiling, likely in association with other omics approaches, may increase the current power of tools predicting thrombolysis-associated sICH in acute ischemic stroke patients. This study represents a free hypothesis-approach pilot study as a continuation from our previous work. Herein, we showed that applying mathematical analyses to extract information from raw big data may result in the identification of new pathophysiological pathways and may complete standard design works.

Endovascular thrombectomy for DAWN- and DEFUSE-3 ineligible acute ischemic stroke patients: a systematic review and meta-analysis

BACKGROUND

Endovascular therapy (EVT) has been proven beneficial for treating acute ischemic strokes (AIS) with large vessel occlusion (LVO). Recent trials of DAWN and DEFUSE-3 have extended the treatment window to 6-24 h, sparking investigations into EVT outcomes for patients not eligible for DAWN/DEFUSE-3 criteria.

PURPOSE

To assess the outcomes of endovascular therapy (EVT) for late-window anterior circulation large vessel occlusion (LVO) in acute ischemic stroke patients, comparing DAWN/DEFUSE-3 eligible (DD) and ineligible (NDND) groups.

METHODS

This systematic review and meta-analysis examined EVT outcomes for patients with late-window anterior circulation LVO beyond 6 h. We categorized patients as DAWN/DEFUSE-3 eligible (DD) and ineligible (NDND). Our search covered PubMed, Embase, Web of Science, and Scopus. A total of 464 records were initially identified. After duplicate removal, 298 studies were screened. Nine studies were included and analyzed. Our analysis focused on study characteristics, baseline comparisons, risk of bias, and outcomes.

RESULTS

Baseline characteristics showed comparable age, gender, most comorbidities, NIHSS score, and ASPECTS between DAWN/DEFUSE-3 eligible (DD) and ineligible (NDND) patients. NDND patients' history showed a higher rate of atrial fibrillation and larger infarct volumes on baseline imaging. Successful reperfusion rates (TICI 2b-3) were similar between DD and NDND with 354 out of 469 in the DD group and 364 out of 459 in the NDND group (OR = 0.86; 95% CI 0.40, 1.84; p = 0.689), though with significant heterogeneity (I2 = 73%; P = 0.002). The proportion of patients with distal occlusions was significantly higher in the NDND group as compared to the DD group (137 (39.4%) of 347 patients versus 47 (11%) of 428 patients, respectively), with significant heterogeneity across studies (I2 = 85%, p = 0.023). Functional independence at 90 days (mRS 0-2) showed no significant difference between groups with 259 out of 802 in the DD group and 197 out of 668 in the NDND group (OR = 1.12; 95% CI 0.77, 1.63; p = 0.552) but also exhibited notable heterogeneity (I2 = 46%, p = 0.063). Symptomatic intracranial hemorrhage (sICH) rates were lower in DD with 14 out of 309 in the DD group and 47 out of 400 in NDND group (OR = 0.49; 95% CI 0.25, 0.93; p = 0.029) as compared to the NDND patients, showing no heterogeneity (I2 = 0%, p = 0.552). 90-day mortality was lower in DD with 43 out of 304 in the DD group and 107 out of 399 in the NDND group (OR = 0.55; 95% CI 0.37, 0.82; p = 0.004) as compared to NDND patients, with no significant heterogeneity (I2 = 0%, p = 0.536).

CONCLUSION

This meta-analysis demonstrates equivalent rates of functional independence between DD and NDND patients. However, the high proportion of distal occlusions and higher rates of sICH and mortality in NDND patients suggest caution in offering mechanical thrombectomy to DAWN/DEFUSE-3 ineligible patients. A more flexible approach to EVT eligibility criteria could benefit select patients in real-world practice. Nonetheless, further research is needed to identify which patients would benefit from expanded EVT eligibility criteria.

Blood-brain barrier permeability by CT perfusion predicts parenchymal hematoma after recanalization with thrombectomy

BACKGROUND AND PURPOSE

Parenchymal hematoma is a dreaded complication of mechanical thrombectomy after acute ischemic stroke. This study evaluated whether blood-brain barrier permeability measurements based on CT perfusion could be used as predictors of parenchymal hematoma after successful recanalization and compared the predictive value of various permeability parameters in patients with acute ischemic stroke.

METHODS

We enrolled 53 patients with acute ischemic stroke who underwent mechanical thrombectomy and achieved successful recanalization. Each patient underwent CT, CT angiography, and CT perfusion imaging before treatment. We used relative volume transfer constant (rKtrans ) values, relative permeability-surface area product (rP·S), and relative extraction fraction (rE) to evaluate preoperative blood-brain barrier permeability in the delayed perfusion area.

RESULTS

Overall, 22 patients (37.7%) developed hemorrhagic transformation after surgery, including 10 patients (16.9%) with hemorrhagic infarction and 11 patients (20.8%) with parenchymal hematoma. The rP·S, rKtrans , and rE of the hypoperfusion area in the parenchymal hematoma group were significantly higher than those in the hemorrhagic infarction and no-hemorrhage transformation groups (p < .01). We found that rE and rP·S were superior to rKtrans in predicting parenchymal hematoma transformation after thrombectomy (P·S area under the curve [AUC] .844 vs. rKtrans AUC .753, z = 2.064, p = .039; rE AUC .907 vs. rKtrans AUC .753, z = 2.399, p = .017).

CONCLUSIONS

Patients with parenchymal hematoma after mechanical thrombectomy had higher blood-brain barrier permeability in hypoperfusion areas. Among blood-brain barrier permeability measurement parameters, rP·S and rE showed better accuracy for parenchymal hematoma prediction.

Prediction factors and clinical significance of different types of hemorrhagic transformation after intravenous thrombolysis

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) after intravenous thrombolysis (IVT) in acute ischemic stroke seriously affects the prognosis of patients. This study aimed to investigate the risk factors of different types of HT and their correlation with prognosis after IVT.

METHODS

Based on the CASE II registry, we included patients with acute ischemic stroke who received IVT within 4.5 h of onset. HT was further divided into hemorrhagic infarction (HI) and parenchymal hemorrhage (PH). Poor outcome was defined as a modified Rankin Scale (mRS) score of 3-6 at 3 months. Multivariate logistic regression analysis was used to determine the independent influencing factors of HT subtypes and clinical outcome.

RESULTS

Among 13108 included patients, 541 (4.1%) developed HI and 440 (3.4%) developed PH. In multivariate analysis, age (OR 1.038, 95% CI 1.028 to 1.049, p < 0.001), atrial fibrillation (OR 1.446, 95% CI 1.141 to 1.943, p = 0.002), baseline diastolic pressure (OR 1.012, 95% CI 1.004 to 1.020, p = 0.005), baseline NIHSS score (OR 1.060, 95% CI 1.049 to 1.071, p < 0.001) and onset to treatment time (OR 1.002, 95% CI 1.000 to 1.004, p = 0.020) independently predicted PH after IVT. In the patients with HT, PH (OR 3.611, 95% CI 2.540 to 5.134, p < 0.001) and remote hemorrhage (OR 1.579, 95% CI 1.115 to 2.235, p = 0.010) were independently related to poor outcome.

CONCLUSIONS

Different types of HT after IVT had different risk factors and clinical significance. The occurrence of PH and remote hemorrhage independently increased the risk of poor outcome.

Pre-treatment risk markers for hemorrhagic transformation in posterior circulation acute ischemic stroke treated with reperfusion therapy

BACKGROUND

Hemorrhagic transformation (HT) is an uncommon complication of posterior circulation acute ischemic stroke (PCS) compared to anterior circulation stroke. Nevertheless, it remains a major concern especially following reperfusion therapy. This study aimed at identifying potential predictive factors associated with HT in PCS.

METHODS

Consecutive patients, from a multicenter cohort, with PCS treated by IVT or EVT or the combination of both, were included from December 2015 to May 2019. The European Cooperative Acute Stroke Study criteria was used to identify HT. Potential risk factors were analyzed using univariate and multivariable testing models.

RESULTS

A total of 96 patients were included in our study. Median age was 66 (57-83) years, 54 patients (56%) were male and median baseline NIHSS was 8 (4-14). 77 patients (80%) received IVT and 54 patients (56%) benefited from EVT. HT occurred in 19 patients (20%), while sHT occurred in 3 patients (3%). HT was found to be associated with poor functional status at 3 months in univariate analysis (p = 0.0084). Multivariable analysis confirmed that higher baseline NIHSS (OR 1.1008; 95% CI [1.0216-1.1862]; p = 0.0117) and lobar topography of ischemia (OR 4.4275; 95% CI [1.3732-14.2753]; p = 0.0127) were independent predictors of the occurrence of HT.

DISCUSSION

HT is associated with increased morbidity in patients with PCS; higher NIHSS and lobar ischemia were independent predictors of HT in our population. Easy-to-use predictive markers may help to tailor therapeutic management of patients with PCS.

Effect of edaravone on symptomatic intracranial hemorrhage in patients with acute large vessel occlusion on apixaban for non-valvular atrial fibrillation

BACKGROUND

Edaravone administration was associated with lower incidence of symptomatic intracranial hemorrhage (sICH) in patients with acute large vessel occlusion (LVO). However, its protective effect on sICH in patients with LVO who receive direct oral anticoagulants for non-valvular atrial fibrillation (NVAF) is uncertain.

OBJECTIVES

To explore the effect of edaravone administration on the incidence of sICH in patients with acute LVO receiving apixaban for NVAF.

METHODS

A Japanese multicenter registry of apixaban on clinical outcome of the patients with LVO or stenosis (ALVO study) included patients who were admitted within 24 h after stroke onset and were received apixaban within 14 days of stroke onset. Patients were divided into two groups according to edaravone administration (Edaravone and No-Edaravone groups). The incidence of sICH within one year and infarct growth before apixaban administration were compared between these groups.

RESULTS

Of the 686 enrolled patients, 622 were included and edaravone was administered to 407 (65.4%). The incidences of sICH in Edaravone and No-Edaravone groups were 1.3% and 5.0%, respectively (p = 0.01). The inverse probability of treatment-weighting (IPTW) hazard ratio (HR) (95% confidence interval [CI]) of Edaravone group for sICH within one year was 0.36 (0.15-0.80) compared to No-Edaravone group. The incidences of infarct growth in Edaravone and No-Edaravone groups were 35.3% and 42.0%, respectively (p = 0.13). IPTW HR (95% CIs) for infarct growth was 0.76 (0.60-0.97).

CONCLUSIONS

Edaravone administration was associated with a lower incidence of sICH in patients with LVO and NVAF who administrated apixaban.

Predictors of functional outcome after symptomatic intracranial hemorrhage complicating intravenous thrombolysis: results from the SITS-ISTR

BACKGROUND AND PURPOSE

Several risk factors of symptomatic intracerebral hemorrhage (SICH) following intravenous thrombolysis for acute ischaemic stroke have been established. However, potential predictors of good functional outcome post-SICH have been less studied.

METHODS

Patient data registered in the Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Register (SITS-ISTR) from 2005 to 2021 were used. Acute ischaemic stroke patients who developed post intravenous thrombolysis SICH according to the SITS Monitoring Study definition were analyzed to identify predictors of functional outcomes.

RESULTS

A total of 1679 patients with reported SICH were included, out of which only 2.8% achieved good functional outcome (modified Rankin Scale scores of 0-2), whilst 80.9% died at 3 months. Higher baseline National Institutes of Health Stroke Scale (NIHSS) score and 24-h ΔNIHSS score were independently associated with a lower likelihood of achieving both good and excellent functional outcomes at 3 months. Baseline NIHSS and hematoma location (presence of both SICHs, defined as remote and local SICH concurrently; n = 478) were predictors of early mortality within 24 h. Independent predictors of 3-month mortality were age, baseline NIHSS, 24-h ΔNIHSS, admission serum glucose values and hematoma location (both SICHs). Age, baseline NIHSS score, 24-h ΔNIHSS, hyperlipidemia, prior stroke/transient ischaemic attack, antiplatelet treatment, diastolic blood pressure at admission, glucose values on admission and SICH location (both SICHs) were associated with reduced disability at 3 months (≥1-point reduction across all modified Rankin Scale scores). Patients with remote SICH (n = 219) and local SICH (n = 964) had comparable clinical outcomes, both before and after propensity score matching.

CONCLUSIONS

Symptomatic intracerebral hemorrhage presents an alarmingly high prevalence of adverse clinical outcomes, with no difference in clinical outcomes between remote and local SICH.

Endovascular Thrombectomy for Acute Stroke with a Large Ischemic Core: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Endovascular thrombectomy (ET) efficacy and safety in stroke with a large ischemic core is still inconclusive as this population has been underrepresented in ET randomized controlled trials (RCTs).

METHODS

We conducted a systematic review and meta-analysis synthesizing RCTs, which were retrieved by systematically searching: PubMed, Web of Science, SCOPUS, and Cochrane through February 18th, 2023. Our primary outcome was neurological disability measured by the modified Rankin scale (mRS). Dichotomous outcomes were pooled using risk ratio (RR) along with confidence interval (CI) using Revman V. 5.4 software.

RESULTS

Three RCTs with a total of 1010 patients were included in our analysis. ET significantly increased the rates of functional independence (mRS ≤ 2) (RR: 2.54 with 95% CI [1.85, 3.48]), independent ambulation (mRS ≤ 3) (RR: 1.78 with 95% CI [1.28, 2.48]), and early neurological improvement (RR: 2.46 with 95% CI [1.60, 3.79]). However, there was no difference between endovascular thrombectomy and medical care in excellent neurological recovery (mRS ≤ 1) (RR: 1.35 with 95% CI [0.88, 2.08]). Also, ET significantly reduced the rate of poor neurological recovery (mRS 4-6) (RR: 0.79 with 95% CI [0.72, 0.86]). However, endovascular thrombectomy was associated with more incidence of any intracranial hemorrhage (RR: 2.40 with 95% CI [1.90, 3.01] [0.72, 0.86]).

CONCLUSION

ET combined with medical care was associated with better functional outcomes compared with medical care alone. However, ET was associated with a higher rate of intracranial hemorrhage. This can support extending ET indication in the management of stroke with a large ischemic core.

Intravenous thrombolysis and endovascular therapy for acute ischemic stroke in COVID-19: a systematic review and meta-analysis

Background

The impact of COVID-19 on clinical outcomes in acute ischemic stroke patients receiving reperfusion therapy remains unclear. We therefore aimed to synthesize the available evidence to investigate the safety and short-term efficacy of reperfusion therapy in this patient population.

Methods

We searched the electronic databases MEDLINE, Embase and Cochrane Library Reviews for randomized controlled trials and observational studies that investigated the use of intravenous thrombolysis, endovascular therapy, or a combination of both in acute ischemic stroke patients with laboratory-confirmed COVID-19, compared to controls. Our primary safety outcomes included any intracerebral hemorrhage (ICH), symptomatic ICH and all-cause in-hospital mortality. Short-term favorable functional outcomes were assessed at discharge and at 3 months. We calculated pooled risk ratios (RR) and 95% confidence intervals (CI) using DerSimonian and Laird random-effects model. Heterogeneity was evaluated using Cochran's Q test and I2 statistics.

Results

We included 11 studies with a total of 477 COVID-19 positive and 8,092 COVID-19 negative ischemic stroke patients who underwent reperfusion therapy. COVID-19 positive patients exhibited a significantly higher risk of experiencing any ICH (RR 1.54, 95% CI 1.16-2.05, p < 0.001), while the nominally increased risk of symptomatic ICH in these patients did not reach statistical significance (RR 2.04, 95% CI 0.97-4.31; p = 0.06). COVID-19 positive stroke patients also had a significantly higher in-hospital mortality compared to COVID-19 negative stroke patients (RR 2.78, 95% CI 2.15-3.59, p < 0.001). Moreover, COVID-19 positive stroke patients were less likely to achieve a favorable functional outcome at discharge (RR 0.66, 95% CI 0.51-0.86, p < 0.001) compared to COVID-19 negative patients, but this difference was not observed at 3-month follow-up (RR 0.64, 95% CI 0.14-2.91, p = 0.56).

Conclusion

COVID-19 appears to have an adverse impact on acute ischemic stroke patients who undergo reperfusion therapy, leading to an elevated risk of any ICH, higher mortality and lower likelihood of favorable functional outcome.

Systematic review registration

PROSPERO, identifier CRD42022309785.

Nanotechnology in Stroke: New Trails with Smaller Scales

Stroke is a leading cause of death, long-term disability, and socioeconomic costs, highlighting the urgent need for effective treatment. During acute phase, intravenous administration of recombinant tissue plasminogen activator (tPA), a thrombolytic agent, and endovascular thrombectomy (EVT), a mechanical intervention to retrieve clots, are the only FDA-approved treatments to re-establish cerebral blood flow. Due to a short therapeutic time window and high potential risk of cerebral hemorrhage, a limited number of acute stroke patients benefit from tPA treatment. EVT can be performed within an extended time window, but such intervention is performed only in patients with occlusion in a larger, anatomically more proximal vasculature and is carried out at specialty centers. Regardless of the method, in case of successful recanalization, ischemia-reperfusion injury represents an additional challenge. Further, tPA disrupts the blood-brain barrier integrity and is neurotoxic, aggravating reperfusion injury. Nanoparticle-based approaches have the potential to circumvent some of the above issues and develop a thrombolytic agent that can be administered safely beyond the time window for tPA treatment. Different attributes of nanoparticles are also being explored to develop a multifunctional thrombolytic agent that, in addition to a thrombolytic agent, can contain therapeutics such as an anti-inflammatory, antioxidant, neuro/vasoprotective, or imaging agent, i.e., a theragnostic agent. The focus of this review is to highlight these advances as they relate to cerebrovascular conditions to improve clinical outcomes in stroke patients.

Mechanical Thrombectomy Versus Best Medical Treatment in the Late Time Window in Non-DEFUSE-Non-DAWN Patients: A Multicenter Cohort Study

BACKGROUND

We assessed the efficacy and safety of mechanical thrombectomy (MT) in adult stroke patients with anterior circulation large vessel occlusion presenting in the late time window not fulfilling the DEFUSE-3 (Thrombectomy for Stroke at 6 to 16 Hours With Selection by Perfusion Imaging trial) and DAWN (Thrombectomy 6 to 24 Hours After Stroke With a Mismatch Between Deficit and Infarct trial) inclusion criteria.

METHODS

Cohort study of adults with anterior circulation large vessel occlusion admitted between 6 and 24 hours after last-seen-well at 5 participating Swiss stroke centers between 2014 and 2021. Mismatch was assessed by computer tomography or magnetic resonance imaging perfusion with automated software (RAPID or OLEA). We excluded patients meeting DEFUSE-3 and DAWN inclusion criteria and compared those who underwent MT with those receiving best medical treatment alone by inverse probability of treatment weighting using the propensity score. The primary efficacy end point was a favorable functional outcome at 90 days, defined as a modified Rankin Scale score shift toward lower categories. The primary safety end point was symptomatic intracranial hemorrhage within 7 days of stroke onset; the secondary was all-cause mortality within 90 days.

RESULTS

Among 278 patients with anterior circulation large vessel occlusion presenting in the late time window, 190 (68%) did not meet the DEFUSE-3 and DAWN inclusion criteria and thus were included in the analyses. Of those, 102 (54%) received MT. In the inverse probability of treatment weighting analysis, patients in the MT group had higher odds of favorable outcomes compared with the best medical treatment alone group (modified Rankin Scale shift: acOR, 1.46 [1.02-2.10]; P=0.04) and lower odds of all-cause mortality within 90 days (aOR, 0.59 [0.37-0.93]; P=0.02). There were no significant differences in symptomatic intracranial hemorrhage (MT versus best medical treatment alone: 5% versus 2%, P=0.63).

CONCLUSIONS

Two out of 3 patients with anterior circulation large vessel occlusion presenting in the late time window did not meet the DEFUSE-3 and DAWN inclusion criteria. In these patients, MT was associated with higher odds of favorable functional outcomes without increased rates of symptomatic intracranial hemorrhage. These findings support the enrollment of patients into ongoing randomized trials on MT in the late window with more permissive inclusion criteria.

S100b in acute ischemic stroke clots is a biomarker for post-thrombectomy intracranial hemorrhages

Background and purpose

Post-thrombectomy intracranial hemorrhages (PTIH) are dangerous complications of acute ischemic stroke (AIS) following mechanical thrombectomy. We aimed to investigate if S100b levels in AIS clots removed by mechanical thrombectomy correlated to increased risk of PTIH.

Methods

We analyzed 122 thrombi from 80 AIS patients in the RESTORE Registry of AIS clots, selecting an equal number of patients having been pre-treated or not with rtPA (40 each group). Within each subgroup, 20 patients had developed PTIH and 20 patients showed no signs of hemorrhage. Gross photos of each clot were taken and extracted clot area (ECA) was measured using ImageJ. Immunohistochemistry for S100b was performed and Orbit Image Analysis was used for quantification. Immunofluorescence was performed to investigate co-localization between S100b and T-lymphocytes, neutrophils and macrophages. Chi-square or Kruskal-Wallis test were used for statistical analysis.

Results

PTIH was associated with higher S100b levels in clots (0.33 [0.08-0.85] vs. 0.07 [0.02-0.27] mm², H1 = 6.021, P = 0.014^*), but S100b levels were not significantly affected by acute thrombolytic treatment (P = 0.386). PTIH was also associated with patients having higher NIHSS at admission (20.0 [17.0-23.0] vs. 14.0 [10.5-19.0], H1 = 8.006, P = 0.005) and higher number of passes during thrombectomy (2 [1-4] vs. 1 [1-2.5], H1 = 5.995, P = 0.014^*). S100b co-localized with neutrophils, macrophages and with T-lymphocytes in the clots.

Conclusions

Higher S100b expression in AIS clots, higher NIHSS at admission and higher number of passes during thrombectomy are all associated with PTIH. Further investigation of S100b expression in AIS clots by neutrophils, macrophages and T-lymphocytes could provide insight into the role of S100b in thromboinflammation.

Poor venous outflow profiles increase the risk of reperfusion hemorrhage after endovascular treatment

To investigate whether unfavorable cerebral venous outflow (VO) predicts reperfusion hemorrhage after endovascular treatment (EVT), we conducted a retrospective multicenter cohort study of patients with acute ischemic stroke and large vessel occlusion (AIS-LVO). 629 AIS-LVO patients met inclusion criteria. VO profiles were assessed on admission CT angiography using the Cortical Vein Opacification Score (COVES). Unfavorable VO was defined as COVES ≤ 2. Reperfusion hemorrhages on follow-up imaging were subdivided into no hemorrhage (noRH), hemorrhagic infarction (HI) and parenchymal hematoma (PH). Patients with PH and HI less frequently achieved good clinical outcomes defined as 90-day modified Rankin Scale scores of ≤ 2 (PH: 13.6% vs. HI: 24.6% vs. noRH: 44.1%; p < 0.001). The occurrence of HI and PH on follow-up imaging was more likely in patients with unfavorable compared to patients with favorable VO (HI: 25.1% vs. 17.4%, p = 0.023; PH: 18.3% vs. 8.5%; p = <0.001). In multivariable regression analyses, unfavorable VO increased the likelihood of PH (aOR: 1.84; 95% CI: 1.03-3.37, p = 0.044) and HI (aOR: 2.05; 95% CI: 1.25-3.43, p = 0.005), independent of age, sex, admission National Institutes Health Stroke Scale scores and arterial collateral status. We conclude that unfavorable VO was associated with the occurrence of HI and PH, both related to worse clinical outcomes.

Association between Infarct Location and Hemorrhagic Transformation of Acute Ischemic Stroke following Successful Recanalization after Mechanical Thrombectomy

BACKGROUND AND PURPOSE

The association between infarct location and hemorrhagic transformation of acute ischemic stroke after mechanical thrombectomy is not understood. We aimed to evaluate the association between CTP-based ischemic core variables at admission and hemorrhagic transformation after a successful thrombectomy.

MATERIALS AND METHODS

We retrospectively analyzed patients who underwent endovascular thrombectomy for acute anterior circulation large-vessel occlusion between October 2019 and June 2021. We enrolled 146 patients with visible ischemic core on pretreatment CTP who had successful reperfusion. The ischemic core infarct territories were classified into the cortical and subcortical areas and then qualitatively and quantitatively analyzed by CTP. Logistic regression and receiver operating characteristic curve analyses were performed to determine the association between ischemic core variables and hemorrhagic transformation.

RESULTS

Of the 146 patients analyzed, 72 (49.3%) had hemorrhagic transformation and 23 (15.8%) had symptomatic intracerebral hemorrhage. Multivariate analysis showed that subcortical infarcts were independently associated with hemorrhagic transformation (OR, 8.06; 95% CI, 2.31-28.10; P = .001) and subcortical infarct volume was independently linked to symptomatic intracerebral hemorrhage (OR, 1.05; 95% CI, 1.01-1.09; P = .039). The receiver operating characteristic curve indicated that subcortical infarcts can predict hemorrhagic transformation accurately (area under the curve = 0.755; 95% CI, 0.68-0.82; P < .001) and subcortical infarct volume can predict symptomatic intracerebral hemorrhage (area under the curve = 0.694; 95% CI, 0.61-0.77; P = .002).

CONCLUSIONS

Subcortical infarcts seen on CTP at admission are associated with hemorrhagic transformation in patients after successful thrombectomy, and subcortical infarct volume may influence the risk of symptomatic intracerebral hemorrhage.

Hypoperfusion Intensity Ratio Is Correlated With the Risk of Parenchymal Hematoma After Endovascular Stroke Treatment

BACKGROUND

Parenchymal hematoma (PH) is a major complication after endovascular treatment (EVT) for ischemic stroke. The hypoperfusion intensity ratio (HIR) represents a perfusion parameter reflecting arterial collateralization and cerebral microperfusion in ischemic brain tissue. We hypothesized that HIR correlates with the risk of PH after EVT.

METHODS

Retrospective multicenter cohort study of patients with large vessel occlusion who underwent EVT between 2013 and 2021 at one of the 2 comprehensive stroke centers (University Medical Center Hamburg-Eppendorf, Germany and Stanford University School of Medicine, CA). HIR was automatically calculated on computed tomography perfusion studies as the ratio of brain volume with time-to-max (Tmax) delay >10 s over volume with Tmax >6 s. Reperfusion hemorrhages were assessed according to the Heidelberg Bleeding Classification. Primary outcome was PH occurrence (PH+) or absence (PH-) on follow-up imaging. Secondary outcome was good clinical outcome defined as a 90-day modified Rankin Scale score of 0 to 2.

RESULTS

A total of 624 patients met the inclusion criteria. We observed PH in 91 (14.6%) patients after EVT. PH+ patients had higher HIR on admission compared with PH- patients (median, 0.6 versus 0.4; P<0.001). In multivariable regression, higher admission blood glucose (adjusted odds ratio [aOR], 1.08 [95% CI, 1.04-1.13]; P<0.001), extensive baseline infarct defined as Alberta Stroke Program Early CT Score ≤5 (aOR, 2.48 [1.37-4.42]; P=0.002), and higher HIR (aOR, 1.22 [1.09-1.38]; P<0.001) were independent determinants of PH after EVT. Both higher HIR (aOR, 0.83 [0.75-0.92]; P<0.001) and PH on follow-up imaging (aOR, 0.39 [0.18-0.80]; P=0.013) were independently associated with lower odds of achieving good clinical outcome.

CONCLUSIONS

Poorer (higher) HIR on admission perfusion imaging was strongly associated with PH occurrence after EVT. HIR as a surrogate for cerebral microperfusion might reflect tissue vulnerability for reperfusion hemorrhages. This automated and quickly available perfusion parameter might help to assess the need for intensive medical care after EVT.

The influence of unexpected early termination of intravenous rt-PA treatment on clinical outcome in acute ischemic stroke patients

INTRODUCTION

This study aimed to explore the impact of unexpected early termination during intravenous thrombolysis on clinical prognosis in patients with acute ischemic stroke (AIS).

METHODS

Patients who received intravenous thrombolysis were divided into an early termination group and a normal treatment group. The causes of unexpected termination were analyzed, and the prognosis was compared between the groups.

RESULTS

The main causes of early termination of thrombolytic therapy included subjective wishes of family members (11.8%, 4) and persistently elevated blood pressure (14.7%, 5). The effective rate of thrombolytic therapy in the early termination group was significantly lower than that in the normal treatment group (P < 0.05). The rate of early neurological deterioration in the early termination group was significantly higher than that in the normal treatment group (P < 0.05). There was no significant difference in the incidence of symptomatic intracranial hemorrhage after thrombolysis between the two groups (P > 0.05). The average mRS score of the early termination group was significantly higher than that of the normal treatment group (P < 0.05). Multivariate analysis indicated that early termination of thrombolytic therapy and cumulative dosage of rt-PA before termination were the main factors affecting the 3-month prognosis.

CONCLUSION

Subjective wishes of family members and persistently elevated blood pressure may be the main causes of early termination of thrombolysis, and the 3-month prognosis of patients could be adversely affected by early termination of thrombolytic therapy and cumulative dosage of rt-PA. Certain measures, such as popularizing thrombolytic health education and optimizing blood pressure management before and during thrombolysis, may be helpful for the normal operation of intravenous thrombolysis.

Role of Neutrophil-Lymphocyte Ratio in the Prognosis of Acute Ischaemic Stroke After Reperfusion Therapy: A Systematic Review and Meta-analysis

Background

Inflammation may mediate response to acute reperfusion therapy (RT) in acute cerebral ischaemia. Neutrophil-lymphocyte ratio (NLR), an inflammatory biomarker, may play an important role in acute ischaemic stroke (AIS) prognostication.

Objective

This meta-analysis sought to examine the effect of NLR on functional outcomes, mortality and adverse outcomes in AIS patients receiving RT.

Methods

Individual studies were retrieved from PubMed/Medline, EMBASE and Cochrane databases. Data were extracted using a standardised data sheet and meta-analysis on association of admission (pre-RT) or delayed (post-RT) NLR with clinical/safety outcomes after RT was conducted.

Results

Thirty-five studies (n = 10 308) were identified for the systematic review with 27 (n = 8537) included in the meta-analyses. Lower admission NLR was associated with good functional outcomes (GFOs), defined as 3-month modified Rankin scale (mRS) 0–2 (SMD = −.46; 95% CI = −.62 to −.29; P < .0001), mRS 0–1 (SMD = −.44; 95% CI = −.66 to −.22; P < .0001) and early neurological improvement (ENI) (SMD = −.55; 95 %CI = −.84 to −.25; P < .0001). Lower delayed admission NLR was also associated with GFOs (SMD = −.80; 95%CI = −.91 to −.68; P < .0001). Higher admission NLR was significantly associated with mortality (SMD = .49; 95%CI = .12 to .85; P = .009), intracerebral haemorrhage (ICH) (SMD = .34; 95% CI = .09 to .59; P = .007), symptomatic ICH (sICH) (SMD = .48; 95% CI = .07 to .90; P = .022) and stroke-associated infection or pneumonia (SMD = .85; 95% CI = .50, 1.19; P < .0001). Higher delayed NLR was significantly associated with sICH (SMD = 1.40; 95% CI = .60 to 2.19; P = .001), ICH (SMD = .94; 95% CI = .41 to 1.46; P < .0001) and mortality (SMD = 1.12; 95% CI = .57 to 1.67; P < .0001). There were variations in outcomes across RT groups.

Conclusion

Higher admission or delayed NLR is significantly associated with worse morbidity, mortality and safety outcomes in AIS patients receiving RT.

Hemorrhagic Transformation After Ischemic Stroke: Mechanisms and Management

Symptomatic hemorrhagic transformation (HT) is one of the complications most likely to lead to death in patients with acute ischemic stroke. HT after acute ischemic stroke is diagnosed when certain areas of cerebral infarction appear as cerebral hemorrhage on radiological images. Its mechanisms are usually explained by disruption of the blood-brain barrier and reperfusion injury that causes leakage of peripheral blood cells. In ischemic infarction, HT may be a natural progression of acute ischemic stroke and can be facilitated or enhanced by reperfusion therapy. Therefore, to balance risks and benefits, HT occurrence in acute stroke settings is an important factor to be considered by physicians to determine whether recanalization therapy should be performed. This review aims to illustrate the pathophysiological mechanisms of HT, outline most HT-related factors after reperfusion therapy, and describe prevention strategies for the occurrence and enlargement of HT, such as blood pressure control. Finally, we propose a promising therapeutic approach based on biological research studies that would help clinicians treat such catastrophic complications.

Difficult questions of intravenous thrombolytic therapy in ischemic stroke

The article reflects the current achievements in the field of reperfusion therapy for ischemic stroke. The data are presented that allow a practicing neurologist to make informed decisions about intravenous thrombolysis in difficult clinical situations: minor stroke, suspected stroke "mask", atypical clinical picture, patient's age over 80 years, posterior circulation stroke, isolated dizziness, severe neurological deficit, large artery occlusion, chronic neuroimaging changes, polymorbidity and low functional level before stroke. It has been shown that an increase in the number of candidates for intravenous thrombolysis can be achieved by intensifying the selection of patients within the 4.5-hour therapeutic window, which primarily implies the optimization of local stroke treatment protocols with a reduction in the door-to-needle time, as well as, in the short term, expanding the therapeutic window. Approaches to reduce the risk of symptomatic hemorrhagic transformation are discussed. We are also talking about a rare but life-threatening complication angioedema. Thus, the intensification of intravenous thrombolysis, as well as an increase in its effectiveness and safety are the primary tasks of each stroke department.

Blood Pressure Management After Endovascular Thrombectomy

Endovascular thrombectomy (EVT) has changed the landscape of acute stroke therapy and has become the standard of care for selected patients presenting with anterior circulation large-vessel occlusion (LVO) stroke. Despite successful reperfusion, many patients with LVO stroke do not regain functional independence. Particularly, patients presenting with extremes of blood pressure (BP) or hemodynamic variability are found to have a worse clinical recovery, suggesting blood pressure optimization as a potential neuroprotective strategy. Current guidelines acknowledge the lack of randomized trials to evaluate the optimal hemodynamic management during the immediate post-stroke period. Following reperfusion, lower blood pressure targets may be warranted to prevent reperfusion injury and promote penumbral recovery, but adequate BP targets adjusted to individual patient factors such as degree of reperfusion, infarct size, and overall hemodynamic status remain undefined. This narrative review outlines the physiological mechanisms of BP control after EVT and summarizes key observational studies and clinical trials evaluating post-EVT BP targets. It also discusses novel treatment strategies and areas of future research that could aid in the determination of the optimal post-EVT blood pressure.

Fibrinogen Level Combined With Platelet Count for Predicting Hemorrhagic Transformation in Acute Ischemic Stroke Patients Treated With Mechanical Thrombectomy

A serious complication of acute ischemic stroke (AIS) after mechanical thrombectomy (MT) is hemorrhagic transformation (HT), which is potentially associated with clinical deterioration. This study examined predictors of HT following MT in AIS patients. Patients with AIS due to large artery occlusion in the anterior circulation, treated with MT and successfully recanalized (modified Thrombolysis in Cerebral Infarction score 2b/3), were studied retrospectively. HT was evaluated by computed tomography (CT) 24 h after MT and was diagnosed and classified into parenchymal hematoma (PH) and hemorrhagic infarction (HI). Multivariate logistic regression models were used to determine the risk factors for HT. Receiver operating characteristic (ROC) curve analysis was performed to determine the predictive utility of risk factors for HT. We enrolled 135 patients: 49 in the HT group and 86 in the non-HT group. The two groups differed significantly in baseline fibrinogen levels (p = 0.003) and platelet counts (p = 0.006). Multivariate logistic regression analyses showed that lower fibrinogen levels [odds ratio (OR), 0.41; 95% CI, 0.23–0.72; p = 0.002] and platelet counts (OR, 0.58; 95% CI, 0.33–0.99; p = 0.048) were independently associated with a higher risk of HT. Together, the binary variates fibrinogen and platelets well-predicted HT (area under the curve, 0.703; specificity, 77.9%; sensitivity, 55.1%). The combination of fibrinogen <2.165 g/L and platelets <171.5 × 10⁹/L was the strongest predictor of HT (OR, 23.17; 95% CI, 5.75–126.80; p < 0.0001). Our study suggests that lower baseline fibrinogen levels and platelet counts may be risk factors for HT in AIS patients following MT and reperfusion. Specifically, the combination of fibrinogen level and platelet count may predict the risk of HT after MT in these patients.