Anticoagulants for acute ischaemic stroke

Revolutionizing Stroke Care: Nanotechnology-Based Brain Delivery as a Novel Paradigm for Treatment and Diagnosis

Stroke, a severe medical condition arising from abnormalities in the coagulation-fibrinolysis cycle and metabolic processes, results in brain cell impairment and injury due to blood flow obstruction within the brain. Prompt and efficient therapeutic approaches are imperative to control and preserve brain functions. Conventional stroke medications, including fibrinolytic agents, play a crucial role in facilitating reperfusion to the ischemic brain. However, their clinical efficacy is hampered by short plasma half-lives, limited brain tissue distribution attributed to the blood-brain barrier (BBB), and lack of targeted drug delivery to the ischemic region. To address these challenges, diverse nanomedicine strategies, such as vesicular systems, polymeric nanoparticles, dendrimers, exosomes, inorganic nanoparticles, and biomimetic nanoparticles, have emerged. These platforms enhance drug pharmacokinetics by facilitating targeted drug accumulation at the ischemic site. By leveraging nanocarriers, engineered drug delivery systems hold the potential to overcome challenges associated with conventional stroke medications. This comprehensive review explores the pathophysiological mechanism underlying stroke and BBB disruption in stroke. Additionally, this review investigates the utilization of nanocarriers for current therapeutic and diagnostic interventions in stroke management. By addressing these aspects, the review aims to provide insight into potential strategies for improving stroke treatment and diagnosis through a nanomedicine approach.

Interactions between integrin α9β1 and VCAM-1 promote neutrophil hyperactivation and mediate poststroke DVT

ABSTRACT

Venous thromboembolic events are significant contributors to morbidity and mortality in patients with stroke. Neutrophils are among the first cells in the blood to respond to stroke and are known to promote deep vein thrombosis (DVT). Integrin α9 is a transmembrane glycoprotein highly expressed on neutrophils and stabilizes neutrophil adhesion to activated endothelium via vascular cell adhesion molecule 1 (VCAM-1). Nevertheless, the causative role of neutrophil integrin α9 in poststroke DVT remains unknown. Here, we found higher neutrophil integrin α9 and plasma VCAM-1 levels in humans and mice with stroke. Using mice with embolic stroke, we observed enhanced DVT severity in a novel model of poststroke DVT. Neutrophil-specific integrin α9-deficient mice (α9fl/flMrp8Cre+/-) exhibited a significant reduction in poststroke DVT severity along with decreased neutrophils and citrullinated histone H3 in thrombi. Unbiased transcriptomics indicated that α9/VCAM-1 interactions induced pathways related to neutrophil inflammation, exocytosis, NF-κB signaling, and chemotaxis. Mechanistic studies revealed that integrin α9/VCAM-1 interactions mediate neutrophil adhesion at the venous shear rate, promote neutrophil hyperactivation, increase phosphorylation of extracellular signal-regulated kinase, and induce endothelial cell apoptosis. Using pharmacogenomic profiling, virtual screening, and in vitro assays, we identified macitentan as a potent inhibitor of integrin α9/VCAM-1 interactions and neutrophil adhesion to activated endothelial cells. Macitentan reduced DVT severity in control mice with and without stroke, but not in α9fl/flMrp8Cre+/- mice, suggesting that macitentan improves DVT outcomes by inhibiting neutrophil integrin α9. Collectively, we uncovered a previously unrecognized and critical pathway involving the α9/VCAM-1 axis in neutrophil hyperactivation and DVT.

Geographic differences in pharmacotherapy patterns and outcomes of acute ischemic stroke in China

BACKGROUND

Vast economic and healthcare status discrepancies exist among regions in China, contributing to different treatment patterns. This study was aimed to investigate the current status of pharmacotherapy for acute ischemic stroke (AIS) and outcomes in China and explore the geographic variation in stroke care.

METHODS

This study was a multicenter prospective registry study, which collected the data of patients with AIS from 80 hospitals in 46 cities in 2015-2017 across China. Poor functional outcome defined as a modified Rankin Scale score of 3-6 was assessed at 3 and 12 months. Multivariate logistic regression was used.

RESULTS

Among 9973 eligible patients, the number of receiving intravenous thrombolysis (IVT), antiplatelet agents, anticoagulants, statin and human urinary kallidinogenase was 429 (4.3%), 9363 (93.9%), 1063 (10.7%), 6828 (74.7%) and 5112 (51.2%), respectively. Multivariable analysis showed IVT use in northeastern was significantly more frequent than in eastern region (OR = 3.17, 95% CI, 2.53-3.99), while the antiplatelets agents use were less frequent (OR = 0.46, 95%CI: 0.38-0.57). The proportions of poor outcomes at 3 and 12 months were 20.7% and 15.8%, respectively. Multivariate analysis showed AIS patients from northeastern and central region had significantly lower risk of poor outcome at month 3 and 12 than those from eastern region (all P < 0.05).

CONCLUSIONS

There was a low IVT use and a high antiplatelet agent and statin use for AIS in China. The pharmacotherapy and prognosis of AIS had variation by geographic region.

TRIAL REGISTRATION

This study was registered with ClinicalTrials.gov (NCT02470624).

Cerebrolysin for acute ischaemic stroke

BACKGROUND

Cerebrolysin is a mixture of low-molecular-weight peptides and amino acids derived from porcine brain, which has potential neuroprotective properties. It is widely used in the treatment of acute ischaemic stroke in Russia, Eastern Europe, China, and other Asian and post-Soviet countries. This is an update of a review first published in 2010 and last updated in 2020.

OBJECTIVES

To assess the benefits and harms of Cerebrolysin or Cerebrolysin-like agents for treating acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Trials Register, CENTRAL, MEDLINE, Embase, Web of Science Core Collection, with Science Citation Index, and LILACS in May 2022 and a number of Russian databases in June 2022. We also searched reference lists, ongoing trials registers, and conference proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing Cerebrolysin or Cerebrolysin-like agents started within 48 hours of stroke onset and continued for any length of time, with placebo or no treatment in people with acute ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Three review authors independently applied the inclusion criteria, assessed trial quality and risk of bias, extracted data, and applied GRADE criteria to the evidence.

MAIN RESULTS

Seven RCTs (1773 participants) met the inclusion criteria of the review. In this update we added one RCT of Cerebrolysin-like agent Cortexin, which contributed 272 participants. We used the same approach for risk of bias assessment that was re-evaluated for the previous update: we added consideration of the public availability of study protocols and reported outcomes to the selective outcome reporting judgement, through identification, examination, and evaluation of study protocols. For the Cerebrolysin studies, we judged the risk of bias for selective outcome reporting to be unclear across all studies; for blinding of participants and personnel to be low in three studies and unclear in the remaining four; and for blinding of outcome assessors to be low in three studies and unclear in four studies. We judged the risk of bias for generation of allocation sequence to be low in one study and unclear in the remaining six studies; for allocation concealment to be low in one study and unclear in six studies; and for incomplete outcome data to be low in three studies and high in the remaining four studies. The manufacturer of Cerebrolysin supported three multicentre studies, either totally, or by providing Cerebrolysin and placebo, randomisation codes, research grants, or statisticians. We judged two studies to be at high risk of other bias and the remaining five studies to be at unclear risk of other bias. We judged the study of Cortexin to be at low risk of bias for incomplete outcome data and at unclear risk of bias for all other domains. All-cause death: Cerebrolysin or Cortexin probably result in little to no difference in all-cause death (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.65 to 1.41; 6 trials, 1689 participants; moderate-certainty evidence). None of the included studies reported on poor functional outcome, defined as death or dependence at the end of the follow-up period, early death (within two weeks of stroke onset), quality of life, or time to restoration of capacity for work. Only one study clearly reported on the cause of death: cerebral infarct (four in the Cerebrolysin and two in the placebo group), heart failure (two in the Cerebrolysin and one in the placebo group), pulmonary embolism (two in the placebo group), and pneumonia (one in the placebo group). Non-death attrition (secondary outcome): Cerebrolysin or similar peptide mixtures may result in little to no difference in non-death attrition, but the evidence is very uncertain, with a considerable level of heterogeneity (RR 0.72, 95% CI 0.38 to 1.39; 6 trials, 1689 participants; very low-certainty evidence). Serious adverse events (SAEs): Cerebrolysin probably results in little to no difference in the total number of people with SAEs (RR 1.16, 95% CI 0.81 to 1.66; 3 trials, 1335 participants; moderate-certainty evidence). This comprised fatal SAEs (RR 0.90, 95% CI 0.59 to 1.38; 3 trials, 1335 participants; moderate-certainty evidence) and an increase in the total number of people with non-fatal SAEs (RR 2.39, 95% CI 1.10 to 5.23; 3 trials, 1335 participants; moderate-certainty evidence). In the subgroup of dosing schedule 30 mL for 10 days (cumulative dose 300 mL), the increase was more prominent (RR 2.87, 95% CI 1.24 to 6.69; 2 trials, 1189 participants). Total number of people with adverse events: Cerebrolysin or similar peptide mixtures may result in little to no difference in the total number of people with adverse events (RR 1.03, 95% CI 0.92 to 1.14; 4 trials, 1607 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Moderate-certainty evidence indicates that Cerebrolysin or Cerebrolysin-like peptide mixtures derived from cattle brain probably have no beneficial effect on preventing all-cause death in acute ischaemic stroke. Moderate-certainty evidence suggests that Cerebrolysin probably has no beneficial effect on the total number of people with serious adverse events. Moderate-certainty evidence also indicates a potential increase in non-fatal serious adverse events with Cerebrolysin use.

Development and verification of a nomogram for predicting short-term mortality in elderly ischemic stroke populations

Stroke is a major healthcare problem worldwide, particularly in the elderly population. Despite limited research on the development of prediction models for mortality in elderly individuals with ischemic stroke, our study aimed to address this knowledge gap. By leveraging data from the Medical Information Mart for Intensive Care IV database, we collected comprehensive raw data pertaining to elderly patients diagnosed with ischemic stroke. Through meticulous screening of clinical variables associated with 28-day mortality, we successfully established a robust nomogram. To assess the performance and clinical utility of our nomogram, various statistical analyses were conducted, including the concordance index, integrated discrimination improvement (IDI), net reclassification index (NRI), calibration curves and decision curve analysis (DCA). Our study comprised a total of 1259 individuals, who were further divided into training (n = 894) and validation (n = 365) cohorts. By identifying several common clinical features, we developed a nomogram that exhibited a concordance index of 0.809 in the training dataset. Notably, our findings demonstrated positive improvements in predictive performance through the IDI and NRI analyses in both cohorts. Furthermore, calibration curves indicated favorable agreement between the predicted and actual incidence of mortality (P > 0.05). DCA curves highlighted the substantial net clinical benefit of our nomogram compared to existing scoring systems used in routine clinical practice. In conclusion, our study successfully constructed and validated a prognostic nomogram, which enables accurate short-term mortality prediction in elderly individuals with ischemic stroke.

Ischemic Stroke as the Presenting Feature for Non-acute Promyelocytic Leukemia Variant of Acute Myeloid Leukemia: A Case Report

Acute myeloid leukemia (AML) patients encounter complications mainly due to their underlying disease or chemotherapy. Although they are at high risk for both hemorrhagic and thrombotic complications, thrombotic vascular complication as an initial manifestation is less common and rarely reported, especially in non-acute promyelocytic leukemia (non-APML). A 58-year-old female with no co-morbidity presented with fever, decreased appetite, headache, and weakness in her left upper and lower limbs. Laboratory findings showed hyperleukocytosis with 90% blast cells and thrombocytopenia (50,000/dl). While investigated and conservatively managed, she developed a seizure and loss of consciousness on the same day and was admitted to the intensive care unit. Computed tomography showed a massive right infarct in the middle cerebral artery territory with a significant midline shift. Flow cytometry indicated the diagnosis of non-APML; chemotherapy, platelet transfusion, unfractionated heparin, mechanical ventilation, and other supportive treatments were started. While managing this case, we faced challenges in decision-making on thrombolysis, craniotomy, and chemotherapy. The case highlights the salient points and dilemmas in managing such an acutely ill patient in critical care.

Stimuli-Responsive Nanotherapeutics for Treatment and Diagnosis of Stroke

Stroke is the second most common medical emergency and constitutes a significant cause of global morbidity. The conventional stroke treatment strategies, including thrombolysis, antiplatelet therapy, endovascular thrombectomy, neuroprotection, neurogenesis, reducing neuroinflammation, oxidative stress, excitotoxicity, hemostatic treatment, do not provide efficient relief to the patients due to lack of appropriate delivery systems, large doses, systemic toxicity. In this context, guiding the nanoparticles toward the ischemic tissues by making them stimuli-responsive can be a turning point in managing stroke. Hence, in this review, we first outline the basics of stroke, including its pathophysiology, factors affecting its development, current treatment therapies, and their limitations. Further, we have discussed stimuli-responsive nanotherapeutics used for diagnosing and treating stroke with challenges ahead for the safe use of nanotherapeutics.

Antithrombotic treatment after stroke due to intracerebral haemorrhage

BACKGROUND

This is an update of the Cochrane Review last published in 2017. Survivors of stroke due to intracerebral haemorrhage (ICH) are at risk of major adverse cardiovascular events (MACE). Antithrombotic (antiplatelet or anticoagulant) treatments may lower the risk of ischaemic MACE after ICH, but they may increase the risk of bleeding.

OBJECTIVES

To determine the overall effectiveness and safety of antithrombotic drugs on MACE and its components for people with ICH.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (5 October 2021). We also searched the Cochrane Central Register of Controlled Trials (CENTRAL: the Cochrane Library 2021, Issue 10), MEDLINE Ovid (from 1948 to October 2021) and Embase Ovid (from 1980 to October 2021). The online registries of clinical trials searched were the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (5 October 2021). We screened the reference lists of included randomised controlled trials (RCTs) for additional, potentially relevant RCTs.

SELECTION CRITERIA

We selected RCTs in which participants with ICH of any age were allocated to a class of antithrombotic treatment as intervention or comparator.

DATA COLLECTION AND ANALYSIS

In accordance with standard methodological procedures recommended by Cochrane, two review authors assessed each selected RCT for its risk of bias and extracted data independently. The primary outcome was a composite of MACE, and secondary outcomes included death, individual components of the MACE composite, ICH growth, functional status and cognitive status. We estimated effects using the frequency of outcomes that occurred during the entire duration of follow-up and calculated a risk ratio (RR) for each RCT. We grouped RCTs separately for analysis according to 1) the class(es) of antithrombotic treatment used for the intervention and comparator, and 2) the duration of antithrombotic treatment use (short term versus long term). We pooled the intention-to-treat populations of RCTs using a fixed-effect model for meta-analysis, but used a random-effects model if RCTs differed substantially in their design or there was considerable heterogeneity (I2 ≥ 75%) in their results. We applied GRADE to assess the certainty of the evidence.

MAIN RESULTS

We identified seven new completed RCTs for this update, resulting in the inclusion of a total of nine RCTs based in secondary care, comprising 1491 participants (average age ranged from 61 to 79 years and the proportion of men ranged from 44% to 67%). The proportion of included RCTs at low risk of bias, by category was: random sequence generation (67%), allocation concealment (67%), performance (22%), detection (78%), attrition (89%), and reporting (78%). For starting versus avoiding short-term prophylactic dose anticoagulation after ICH, no RCT reported MACE. The evidence is very uncertain about the effect of starting short-term prophylactic dose anticoagulation on death (RR 1.00, 95% CI 0.59 to 1.70, P = 1.00; 3 RCTs; very low-certainty evidence), venous thromboembolism (RR 0.84, 95% CI 0.51 to 1.37, P = 0.49; 4 RCTs; very low-certainty evidence), ICH (RR 0.24, 95% CI 0.04 to 1.38, P = 0.11; 2 RCTs; very low-certainty evidence), and independent functional status (RR 2.03, 95% CI 0.78 to 5.25, P = 0.15; 1 RCT; very low-certainty evidence) over 90 days. For starting versus avoiding long-term therapeutic dose oral anticoagulation for atrial fibrillation after ICH, starting long-term therapeutic dose oral anticoagulation probably reduces MACE (RR 0.61, 95% CI 0.40 to 0.94, P = 0.02; 3 RCTs; moderate-certainty evidence) and probably reduces all major occlusive vascular events (RR 0.27, 95% CI 0.14 to 0.53, P = 0.0002; 3 RCTs; moderate-certainty evidence), but probably results in little to no difference in death (RR 1.05, 95% CI 0.62 to 1.78, P = 0.86; 3 RCTs; moderate-certainty evidence), probably increases intracranial haemorrhage (RR 2.43, 95% CI 0.88 to 6.73, P = 0.09; 3 RCTs; moderate-certainty evidence), and may result in little to no difference in independent functional status (RR 0.98, 95% CI 0.78 to 1.24, P = 0.87; 2 RCTs; low-certainty evidence) over one to three years. For starting versus avoiding long-term antiplatelet therapy after ICH, the evidence is uncertain about the effects of starting long-term antiplatelet therapy on MACE (RR 0.89, 95% CI 0.64 to 1.22, P = 0.46; 1 RCT; moderate-certainty evidence), death (RR 1.08, 95% CI 0.76 to 1.53, P = 0.66; 1 RCT; moderate-certainty evidence), all major occlusive vascular events (RR 1.03, 95% CI 0.68 to 1.55, P = 0.90; 1 RCT; moderate-certainty evidence), ICH (RR 0.52, 95% CI 0.27 to 1.03, P = 0.06; 1 RCT; moderate-certainty evidence) and independent functional status (RR 0.95, 95% CI 0.77 to 1.18, P = 0.67; 1 RCT; moderate-certainty evidence) over a median follow-up of two years. For adults within 180 days of non-cardioembolic ischaemic stroke or transient ischaemic attack and a clinical history of prior ICH, there was no evidence of an effect of long-term cilostazol compared to aspirin on MACE (RR 1.33, 95% CI 0.74 to 2.40, P = 0.34; subgroup of 1 RCT; low-certainty evidence), death (RR 1.65, 95% CI 0.55 to 4.91, P = 0.37; subgroup of 1 RCT; low-certainty evidence), or ICH (RR 1.29, 95% CI 0.35 to 4.69, P = 0.70; subgroup of 1 RCT; low-certainty evidence) over a median follow-up of 1.8 years; all major occlusive vascular events and functional status were not reported.

AUTHORS' CONCLUSIONS

We did not identify beneficial or hazardous effects of short-term prophylactic dose parenteral anticoagulation and long-term oral antiplatelet therapy after ICH on important outcomes. Although there was a significant reduction in MACE and all major occlusive vascular events after long-term treatment with therapeutic dose oral anticoagulation for atrial fibrillation after ICH, the pooled estimates were imprecise, the certainty of evidence was only moderate, and effects on other important outcomes were uncertain. Large RCTs with a low risk of bias are required to resolve the ongoing dilemmas about antithrombotic treatment after ICH.

Investigational drugs for ischemic stroke: what's in the clinical development pipeline for acute phase and prevention?

INTRODUCTION

Stroke is a leading cause of disability and mortality and its burden expected to increase. The only approved drug for acute ischemic stroke is the intravenous thrombolytic alteplase. The risk of bleeding complications is one of the reasons for the undertreatment of eligible patients. Numerous drugs are currently being developed to improve safety-efficacy.

AREAS COVERED

We reviewed literature from January 1^st, 2000, to 15^th January 2022 for the development and testing of novel drugs with the aim of targeting treatment at prevention of ischemic stroke: PubMed, MEDLINE, Google Scholar, and ClinicalTrial.gov.

EXPERT OPINION

The pathophysiology of ischemic stroke involves multiple pathways causing cerebral artery obstruction and brain tissue ischemia. Data suggest that tenecteplase is a more promising fibrinolytic agent with a superior efficacy-safety profile, compared to the currently approved alteplase. Current guidelines consider a short-term cycle of mannitol or hypertonic saline to be advisable in patients with space-occupying hemispheric infarction. Regarding primary and secondary prevention, research is primarily focused on identifying mechanisms to improve the safety-efficacy profile using a "hemostasis-sparing" approach. Further evaluation on those agents that have already shown promise for their risk/benefit profiles, would benefit greatly a neurologist's capacity to successfully prevent and treat ischemic stroke patients.

Efficacy and safety of argatroban in treatment of acute ischemic stroke: A meta-analysis

BACKGROUND

Argatroban is a novel direct thrombin inhibitor that has been used for treatment of acute ischemic stroke (AIS). To our knowledge, no systematic analysis has assessed the efficacy and safety of argatroban for treatment of AIS.

AIM

To evaluate the efficacy and safety of argatroban for treatment of AIS.

METHODS

Cochrane Library, Medline, PubMed, and Web of Science were searched to retrieve all studies associated with argatroban and AIS. Effective rate, adverse events rate, and 95% confidence intervals were calculated and pooled using meta-analysis methodology.

RESULTS

We only found four randomized controlled studies, comprising 354 cases with 213 in the argatroban group and 141 in the control group. Great heterogeneity was found in the four studies (c² = 11.44, I² = 74%, P = 0.01). Subgroup analysis could not be performed because of the absence of detailed data. The two most recent studies showed acceptable heterogeneity (c² = 1.56, I² = 36%, P = 0.21). Our analysis showed that argatroban was not more effective than the control therapy in the acute phase of ischemic stroke (Z = 0.01, P = 0.99). Argatroban did not increase the risk of bleeding compared with the control group (c² = 0.37, I² = 0%, P = 0.54, Z = 0.80, P = 0.42).

CONCLUSION

Patients with AIS might not benefit from argatroban and combination therapy with argatroban does not increase bleeding tendency.