Low-dose intravenous tissue plasminogen activator for acute ischaemic stroke: an alternative or a new standard?

Ischemic stroke pathophysiology: A bibliometric and visualization analysis from 1990 to 2022

Background

Pathophysiology plays a significant role in the scientific study of ischemic stroke, and has attracted increasing interest from researchers in the field. However, a comprehensive bibliometric analysis is lacking in this field. The purpose of this study is to identify the current research status and hotspots of ischemic stroke pathophysiology from a bibliometric perspective.

Methods

The Web of Science Core Collection database was searched for articles published from 1990 to 2022. CiteSpace, VOSviewer, and R package "bibliometrix" software were used to analyze countries/regions, institutions, journals, authors, papers, and keywords to predict the latest trends in ischemic stroke pathophysiology research.

Results

This analysis collected 7578 records of ischemic stroke pathophysiology. China and America emerged as the leading countries in this field, with Harvard University being the most active institution. Among journals and authors in this field, journal Stroke and author Gregory YH Lip published the most papers, while Nature Medicine was the journal with the highest citation per article. Keywords and co-citation clusters were closely related to "central nervous system", "mechanisms", "biochemistry & molecular biology" and "radiology, nuclear medicine & medical imaging", while other related fields, such as peripheral organs damage induced by the central nervous system and rehabilitation after ischemic stroke, require further research efforts.

Conclusion

This is the first bibliometric study that comprehensively mapped out the knowledge structure and development trends of ischemic stroke pathophysiology in recent 32 years, which may provide a reference for scholars to explore ischemic stroke pathophysiology.

Analyses on safety and efficacy of non-standard dose of r-tPA in intravenous thrombolysis-treated AIS patients

Background

Intravenous 0.9 mg/kg recombinant tissue plasminogen activator (r-tPA) is one of the most effective treatments in acute ischemic stroke patients. Practically, the dose of r-tPA is still a topic that is constantly being discussed.

Methods

For this observational study, data were obtained from 537 patients who received r-tPA thrombolysis at Shanghai Sixth People's Hospital stroke center over 5 years (2014–2019). Patients were divided into two groups: a non-standard dose group (0.6 mg/kg ≤ dose < 0.9 mg/kg) and a standard dose group (0.9 mg/kg). Different outcomes were observed: efficacy: 3 months mRS 0-1 (3m-mRS0-1); safety: symptomatic intracranial hemorrhage within 24 h (24h-sICH) and 3 months mortality (3m-death). We also observed the effect of r-tPA dose coefficient on outcomes in different age groups and baseline National Institute of Health stroke scale (NIHSS) score subgroups.

Results

There were 265 patients who gave the standard dose treatment and 272 gave the nonstandard dose. There was no significant difference between the non-standard dose group and the standard dose group in 3m-mRS0-1, 3m-death, and 24h-sICH (p = 0.567, 0.327, and 0.415, respectively). The dose coefficient presents a significant negative correlation (p = 0.034, B = −4.290) with 3m-death in NIHSS < 16 sub-group. Door-to-needle time (DNT) is the most important independent outcome-influential factor (MIOIF) in the NIHSS ≥16 sub-group. The diabetes history and baseline NIHSS score were the MIOIF in the age ≥80-year sub-group.

Conclusions

The non-standard dose group (0.6 mg/kg ≤ dose < 0.9 mg/kg) shows no difference in safety and effectiveness than the standard dose group (0.9 mg/kg) in our study. The standard dose should be considered first according to current evidence and Guidelines, but the non-standard dose (0.6 mg/kg ≤ dose < 0.9 mg/kg) might be an option in the actual diagnosis and treatment process considering the patient's clinical profile and financial condition.

The feasibility and accuracy of machine learning in improving safety and efficiency of thrombolysis for patients with stroke: Literature review and proposed improvements

In the treatment of ischemic stroke, timely and efficient recanalization of occluded brain arteries can successfully salvage the ischemic brain. Thrombolysis is the first-line treatment for ischemic stroke. Machine learning models have the potential to select patients who could benefit the most from thrombolysis. In this study, we identified 29 related previous machine learning models, reviewed the models on the accuracy and feasibility, and proposed corresponding improvements. Regarding accuracy, lack of long-term outcome, treatment option consideration, and advanced radiological features were found in many previous studies in terms of model conceptualization. Regarding interpretability, most of the previous models chose restrictive models for high interpretability and did not mention processing time consideration. In the future, model conceptualization could be improved based on comprehensive neurological domain knowledge and feasibility needs to be achieved by elaborate computer science algorithms to increase the interpretability of flexible algorithms and shorten the processing time of the pipeline interpreting medical images.

Low-dose versus standard-dose alteplase for intravenous thrombolysis in patients with acute ischemic stroke in Iran: Results from the safe implementation of treatments in stroke registry

Background: Rates of intracranial hemorrhage (ICH) after intravenous thrombolysis (IVT) differ depending on ethnicity, one reason that few Eastern countries have approved a lower dose of alteplase. Data in this regard are scarce in the Middle Eastern region. Methods: The present retrospective study was performed on data extracted from the Safe Implementation of Treatments in Stroke (SITS) registry. Computed tomography (CT) image analysis was based on the SITS-Monitoring Study (SITS-MOST) definition for symptomatic ICH (SICH). Functional outcome at 3 months was assessed using the modified Rankin Scale (mRS). Multivariate logistic regression including adjusted analysis was used for comparison between groups. Results: Of 6615 patients, 1055 were enrolled. A total of 86% (n = 906) received a standard dose and 14% (n = 149) received a low dose of alteplase. Favorable 3-month outcome was achieved in 481 (53%) patients in the standard group and 71 (48%) patients in the low-dose group [adjusted odds ratio (AOR) = 1.24, 95% confidence interval (CI): 0.87-1.75, P = 0.218]. SICH occurred in 14 (1.5%) patients in the standard group and 3 (2%) patients in the low-dose group [odds ratio (OR) = 2.77, 95% CI: 0.36-21.04, P = 0.120]. At 3 months, mortality occurred in 145 (16.0%) patients in the standard group and 29 (19.4%) patients in the low-dose group (OR = 1.22, 95% CI: 0.78-1.91, P = 0.346). Conclusion: Low-dose compared to standard-dose alteplase for patients with acute ischemic stroke (AIS) was not associated with fewer hemorrhagic events and there was no significant difference in the favorable 3-month outcome (mRS: 0-2) or mortality rate.

Acute Reperfusion Therapies for Acute Ischemic Stroke

The field of acute stroke treatment has made tremendous progress in reducing the overall burden of disability. Understanding the pathophysiology of acute ischemic injury, neuroimaging to quantify the extent of penumbra and infarction, and acute stroke reperfusion therapies have together contributed to these advancements. In this review we highlight advancements in reperfusion therapies for acute ischemic stroke.

The safety and effectiveness of early anti-platelet therapy after alteplase for acute ischemic stroke: A meta-analysis

BACKGROUND

For acute ischemic stroke patients, there is a risk of reocclusion after intravenous thrombolysis. In theory, early anti-platelet therapy can reduce the risk of vessel reocclusion. Although current guidelines do not recommend routine anti-platelet therapy within 24 h of intravenous thrombolytic therapy, many studies disagreed with it, especially after the emergence of new anti-platelet drugs. It is necessary to conduct a meta-analysis based on high-quality randomized controlled studies to re-evaluate this treatment strategy.

METHODS

Literature retrieval was systematically conducted in PubMed, Embase, Cochrane, Web of sicence, clinical trials, CNKI and Wanfang Data, for searching randomized controlled trials (published between January 1, 2000 and April 30, 2020 with no language restrictions) comparing early (within 24 h) with routine (after 24 h) anti-platelet-aggregation therapy after rt-PA intravenous thrombolysis. The primary safety endpoint and primary efficacy indicator are the incidence of symptomatic intracranial hemorrhage and a good prognosis at 90-day (modified Rankin Scale (mRS) score of 0-1 or return to baseline mRS), respectively. We assessed pooled data by use of a random-effects model.

FINDINGS

Of the 378 identified studies, only 3 were eligible and included in our analysis (N = 1008 participants). Compared with routine treatment, early anti-platelet-aggregation therapy after rt-PA intravenous thrombolysis in acute ischemic stroke patients did not affect the 90-day efficacy (95% CI 0.97 - 1.32). In terms of safety assessment, the early use of anti-platelet-aggregation drugs after thrombolysis has a neutral effect on the risk of intracranial hemorrhage, symptomatic intracranial hemorrhage, and bleeding from other systemic sites.

CONCLUSION

Early anti-platelet therapy after alteplase did not benefit the acute ischemic stroke patients based on the current evidence. However, more clinical trials and statistical evidence are still needed.

Computational Simulations of Thrombolytic Therapy in Acute Ischaemic Stroke

Ischaemic stroke can occur when an artery to the brain is blocked by a blood clot. The use of thrombolytic agents, such as tissue plasminogen activator (tPA), to dissolve the occluding clot is limited by the risk of intracerebral haemorrhage (ICH), a known side effect associated with tPA. We developed a computational thrombolysis model for a 3D patient-specific artery coupled with a compartmental model for temporal concentrations of tPA and lysis proteins during intravenous infusion of tPA, in order to evaluate the effects of tPA dose on the efficacy of thrombolytic therapy and the risk of ICH. The model was applied to a 3-mm-long fibrin clot with two different fibrin fibre radii in the middle cerebral artery (MCA) - a setting relevant to ischaemic stroke, and results for different tPA dose levels and fibrin fibre radii were compared. Our simulation results showed that clot lysis was accelerated at higher tPA doses at the expense of a substantial increase in the risk of ICH. It was also found that a fine clot with a smaller fibre radius dissolved much slowly than a coarse clot due to a slower tPA penetration into the clots.

Erythrocyte-Derived Nanoparticles as a Theranostic Agent for Near-Infrared Fluorescence Imaging and Thrombolysis of Blood Clots

Ischemic stroke occurs when a blood clot obstructs or narrows the arteries that supply blood to the brain. Currently, tissue plasminogen activator (tPA), a thrombolytic agent, is the only United States Food and Drug Administration (FDA)-approved pharmacologic treatment for ischemic stroke. Despite its effective usage, the major limitation of tPA that stems from its short half-life in plasma (≈5 min) is the potential for increased risk of hemorrhagic complications. To circumvent these limitations, herein, the first proof-of-principle demonstration of a theranostic nanoconstruct system derived from erythrocytes doped with the FDA-approved near-infrared (NIR) imaging agent, indocyanine green, and surface-functionalized with tPA is reported. Using a clot model, the dual functionality of these nanoconstructs in NIR fluorescence imaging and clot lysis is demonstrated. These biomimetic theranostic nanoconstructs may ultimately be effective in imaging and treatment of blood clots involved in ischemic stroke.

Low- versus Standard-Dose Intravenous Tissue-Type Plasminogen Activator for Acute Ischemic Stroke: An Updated Meta-Analysis

BACKGROUND

We performed a meta-analysis to compare the efficacy and safety between low- and standard-dose intravenous (IV) tissue-type plasminogen activator (tPA) for acute ischemic stroke (AIS) patients within 4.5 hours of symptom onset.

METHODS

We searched PubMed and EMBASE for relevant studies from inception to June1, 2017. Cohort or randomized controlled studies for AIS within 4.5 hours of symptom onset with comparison between low-dose and standard-dose tPA were included. The primary efficacy end point was favorable functional outcome (modified Rankin scale scores [mRS] of 0-1) at 90 days. The primary safety end point was the incidence rate of symptomatic intracerebral hemorrhage (sICH). The secondary end points were independent functional outcome (mRS scores of 0-2) and mortality.

RESULTS

A total of 11 studies were pooled in this meta-analysis. The low-dose strategy appeared to be as effective as standard-dose tPA (43.4% versus 45.4%; odds ratio [OR] = 0.93, 95% confidence interval [CI]: 0.78-1.10; P = .38) in primary efficacy outcome. The secondary efficacy outcome produced similar results (57.3% versus 57.0%; OR = 0.95, 95% CI: 0.86-1.05; P= .33). There was no evidence of statistical difference for sICH (4.2% versus 4.9%; OR = 1.02 [0.66-1.55]; P = .94) and mortality (9.0% versus 10.6%; OR = 0.99 [0.74-1.31]; P = .92) at 90 days between low- and standard-dose therapy. In a subgroup analysis by ethnicity, there was no significant difference between patients of Asian and non-Asian descent for any of the end points.

CONCLUSIONS

This study showed that AIS patients receiving low-dose IV-tPA had comparably efficacy and safety to those receiving standard-dose IV-tPA. However, the effect is especially pronounced within the Asian population, which limits the generalizability of these results.