Whatʼs the “Hyper” in Hyperacute Stroke?: Strategies to Improve Outcomes in Ischemic Stroke Patients Presenting Within 6 Hours

Emergency Department and Critical Care Use of Clevidipine for Treatment of Hypertension in Patients With Acute Stroke

BACKGROUND AND PURPOSE

Clevidipine is a parenteral dihydropyridine calcium channel blocker that received Food and Drug Administration approval in 2008 for the reduction of blood pressure (BP) when oral therapy is not feasible or not desirable. Soon after approval, our institution incorporated clevidipine into protocols for the management of hypertension among acute stroke patients, based on the drug's rapid onset of action and straightforward titration to goal. A subsequent retrospective review of its use in otherwise alteplase-eligible ischemic stroke patients with BP greater than 185/110 mm Hg (n = 32, in 2014) revealed that clevidipine in that setting demonstrated the shortest median time to BP control, the shortest median door-to-alteplase administration time, and the lowest administered volume of any parenteral antihypertensive used. As a result, clinical protocols in our institution were modified to make clevidipine first-line antihypertensive in both ischemic and hemorrhagic acute stroke. In this study, we report our institution's experience with clevidipine in acute stroke, comprising the largest such report to date.

METHODS

We conducted a retrospective chart review of all acute stroke patients who received clevidipine in the emergency department (ED) or intensive care unit (ICU) (n = 295) for the management of clinically significant hypertension between January 1, 2015, and December 31, 2017. Metrics analyzed included target (goal) BP for thrombolysis eligibility among patients intended for lytic therapy according to stroke management guidelines in effect at the time of care.

RESULTS

The median time for initial parenteral antihypertensive dose to goal (DTG) BP for all ischemic stroke patients (both those intended for and those not intended for lytic therapy) with complete data (n = 71 of 204) was 15 minutes; median time for door-to-IV-alteplase administration for ischemic stroke patients with complete data (n = 14 of 34 treated patients) was 59 minutes. The median time for initial parenteral antihypertensive DTG BP for all hemorrhagic stroke patients with complete data (n = 33 of 91 treated patients) was 39 minutes.

CONCLUSIONS

We conclude that the salutary findings of the initial small study are valid across a larger patient sample of all acute stroke types. Based on these data, clevidipine is shown to be safe, consistent, and effective in the treatment of acute hypertension in ischemic and hemorrhagic stroke events, and is a reasonable first-line treatment option for acute hypertension in this setting.

The Transcriptional Landscape of Pericytes in Acute Ischemic Stroke

The current treatment options for ischemic stroke aim to achieve reperfusion but are time critical. Novel therapeutic approaches that can be given beyond the limited time window of 3-4.5 h are still an unmet need to be addressed to improve stroke outcomes. The lack of oxygen and glucose in the area of ischemic injury initiates a pathological cascade leading to blood-brain barrier (BBB) breakdown, inflammation, and neuronal cell death, a process that may be intercepted to limit stroke progression. Pericytes located at the blood/brain interface are one of the first responders to hypoxia in stroke and therefore a potential target cell for early stroke interventions. Using single-cell RNA sequencing in a mouse model of permanent middle cerebral artery occlusion, we investigated the temporal differences in transcriptomic signatures in pericytes at 1, 12, and 24 h after stroke. Our results reveal a stroke-specific subcluster of pericytes that is present at 12 and 24 h and characterized by the upregulation of genes mainly related to cytokine signaling and immune response. This study identifies temporal transcriptional changes in the acute phase of ischemic stroke that reflect the early response of pericytes to the ischemic insult and its secondary consequences and may constitute potential future therapeutic targets.

Evaluating the effects of simulation training on stroke thrombolysis: a systematic review and meta-analysis

BACKGROUND

Ischaemic strokes are medical emergencies, and reperfusion treatment, most commonly intravenous thrombolysis, is time-critical. Thrombolysis administration relies on well-organised pathways of care with highly skilled and efficient clinicians. Simulation training is a widespread teaching modality, but results from studies on the impact of this intervention have yet to be synthesised. This systematic review and meta-analysis aimed to synthesise the evidence and provide a recommendation regarding the effects of simulation training for healthcare professionals on door-to-needle time in the emergency thrombolysis of patients with ischaemic stroke.

METHODS

Seven electronic databases were systematically searched (last updated 12th July 2023) for eligible full-text articles and conference abstracts. Results were screened for relevance by two independent reviewers. The primary outcome was door-to-needle time for recombinant tissue plasminogen activator administration in emergency patients with ischaemic stroke. The secondary outcomes were learner-centred, improvements in knowledge and communication, self-perceived usefulness of training, and feeling 'safe' in thrombolysis-related decision-making. Data were extracted, risk of study bias assessed, and analysis was performed using RevMan™ software (Web version 5.6.0, The Cochrane Collaboration). The quality of the evidence was assessed using the Medical Education Research Study Quality Instrument.

RESULTS

Eleven studies were included in the meta-analysis and nineteen in the qualitative synthesis (n = 20,189 total patients). There were statistically significant effects of simulation training in reducing door-to-needle time; mean difference of 15 min [95% confidence intervals (CI) 8 to 21 min]; in improving healthcare professionals' acute stroke care knowledge; risk ratio (RR) 0.42 (95% CI 0.30 to 0.60); and in feeling 'safe' in thrombolysis-related decision-making; RR 0.46 (95% CI 0.36 to 0.59). Furthermore, simulation training improved healthcare professionals' communication and was self-perceived as useful training.

CONCLUSION

This meta-analysis showed that simulation training improves door-to-needle times for the delivery of thrombolysis in ischaemic stroke. However, results should be interpreted with caution due to the heterogeneity of the included studies.

S100ß, Matrix Metalloproteinase-9, D-dimer, and Heat Shock Protein 70 Are Serologic Biomarkers of Acute Cerebral Infarction in a Mouse Model of Transient MCA Occlusion

Objective

Diagnosing acute cerebral infarction is crucial in determining prognosis of stroke patients. Although many serologic tests for prompt diagnosis are available, the clinical application of serologic tests is currently limited. We investigated whether S100β, matrix metalloproteinase-9 (MMP-9), D-dimer, and heat shock protein 70 (HSP70) can be used as biomarkers for acute cerebral infarction.

Methods

Focal cerebral ischemia was induced using the modified intraluminal filament technique. Mice were randomly assigned to 30-minute occlusion (n=10), 60-minute occlusion (n=10), or sham (n=5) groups. Four hours later, neurological deficits were evaluated and blood samples were obtained. Infarction volumes were calculated and plasma S100β, MMP-9, D-dimer, and HSP70 levels were measured using enzyme-linked immunosorbent assay.

Results

The average infarction volume was 12.32±2.31 mm³ and 46.9±7.43 mm³ in the 30- and 60-minute groups, respectively. The mean neurological score in the two ischemic groups was 1.6±0.55 and 3.2±0.70, respectively. S100β, MMP-9, and HSP70 expressions significantly increased after 4 hours of ischemia (p=0.001). Furthermore, S100β and MMP-9 expressions correlated with infarction volumes (p<0.001) and neurological deficits (p<0.001). There was no significant difference in D-dimer expression between groups (p=0.843). The area under the receiver operating characteristic curve (AUC) showed high sensitivity and specificity for MMP-9, HSP70 (AUC=1), and S100β (AUC=0.98).

Conclusion

S100β, MMP-9, and HSP70 can complement current diagnostic tools to assess cerebral infarction, suggesting their use as potential biomarkers for acute cerebral infarction.

Mechanisms of action of hyperbaric oxygenation in stroke: a review

This article outlines the therapeutic mechanisms of hyperbaric oxygenation in acute stroke, based on information obtained from peer-reviewed medical literature. Hyperbaric oxygen is an approved treatment modality for ischemia-reperfusion injury in several conditions. It maintains the viability of the marginal tissue, reduces the mitochondrial dysfunction, metabolic penumbra, and blocks inflammatory cascades observed in acute stroke. Basic and clinical data suggest that hyperbaric oxygen could be a safe and effective treatment option in the management of acute stroke. Further work is needed to clarify its clinical utility when applied within the treatment window of "gold standard" treatments (<3-5 hours).