Outcomes of asymptomatic recombinant tissue plasminogen activator associated intracranial hemorrhage

Analysis of rescue strategies for acute thrombosis during STA-MCA bypass surgery and the literature review

BACKGROUND AND OBJECTIVES

STA-MCA bypass surgery is mainly used for Moyamoya disease, giant intracranial aneurysms, and resection of intracranial tumors requiring sacrifice of blood vessels. The intraoperative patency of the reconstructive vessels is critical to the efficacy of the procedure. This study aimed to evaluate the efficacy of intra-arterially infused tirofiban for the treatment of acute thrombosis during STA-MCA bypass surgery and countermeasures for acute thrombosis.

METHODS

This study involved 209 patients (272 hemispheres) who underwent STA-MCA surgery between November 2020 and December 2023. Intraoperative acute thrombosis occurred in eight patients (3.83%,8 hemispheres). We retrospectively reviewed the clinical and imaging data, surgical procedure, and follow-up outcomes of eight patients. We implemented the different thrombolytic methods to evaluate the optimal thrombosis management during the bypass surgery. After three months, we assessed neurological functions using the modified Rankin Scale (mRS) and conducted a literature review using PubMed.

RESULTS

Eight patients (four male patients and four female patients) developed acute thrombosis during the bypass surgery. Of the eight patients, two underwent re-anastomosis after thrombus removal, three received local injections of tirofiban into the anastomosis or the branches of the superficial temporal artery, and three underwent superselective intra-arterial tirofiban infusion using a microcatheter. Thrombosis were resolved, and arteries were recanalized in all patients. The mRS score was 0 in all patients. No major ischemic or hemorrhagic complications occurred.

CONCLUSION

Our treatment methods were efficacious in the management of acute thrombosis. Intra-arterial tirofiban administration seems to be a simple and effective treatment option for acute thrombosis during STA-MCA bypass surgery.

Targeted Thrombolysis with Magnetic Nanotherapeutics: A Translational Assessment

Plasminogen activators, such as recombinant tissue-type plasminogen activators (rtPAs), while effective in treating thromboembolic diseases, often induce hemorrhagic complications due to non-specific enzyme activities in the systemic circulation. This study evaluated the targeting efficiency, efficacy, biodistribution, and potential toxicity of a rtPA covalently attached to chitosan-coated magnetic nanoparticles (chitosan-MNP-rtPA). The thrombolytic activity of a chitosan-MNP-rtPA was preserved by protection from an endogenous plasminogen activator inhibitor-1 (PAI-1) in whole blood and after circulation in vivo, as examined by thromboelastometry. Single-photon emission computed tomography (SPECT) demonstrated real-time retention of a 99mTc-MNP-rtPA induced by magnet application in a rat embolic model; an 80% reduction in rtPA dosage for a chitosan-MNP-rtPA with magnetic guidance was shown to restore blood flow. After treatment, iron deposition was observed in the reticuloendothelial systems, with portal edema and neutrophil infiltration in the liver at a ten-fold higher dose but not the regular dose. Nevertheless, no liver or renal toxicity was observed at this higher dose. In conclusion, the liver may still be the major deposit site of rtPA nanocomposites after targeted delivery; chitosan-coated MNPs are potentially amenable to target therapeutics with parenteral administration.

The Role of Neutrophils in Multiple Sclerosis and Ischemic Stroke

Inflammation plays an important role in numerous central nervous system (CNS) disorders. Its role is ambiguous-it can induce detrimental effects, as well as repair and recovery. In response to injury or infection, resident CNS cells secrete numerous factors that alter blood-brain barrier (BBB) function and recruit immune cells into the brain, like neutrophils. Their role in the pathophysiology of CNS diseases, like multiple sclerosis (MS) and stroke, is highly recognized. Neutrophils alter BBB permeability and attract other immune cells into the CNS. Previously, neutrophils were considered a homogenous population. Nowadays, it is known that various subtypes of these cells exist, which reveal proinflammatory or immunosuppressive functions. The primary goal of this review was to discuss the current knowledge regarding the important role of neutrophils in MS and stroke development and progression. As the pathogenesis of these two disorders is completely different, it gives the opportunity to get insight into diverse mechanisms of neutrophil involvement in brain pathology. Our understanding of the role of neutrophils in CNS diseases is still evolving as new aspects of their activity are being unraveled. Neutrophil plasticity adds another level to their functional complexity and their importance for CNS pathophysiology.

Acupuncture Extended the Thrombolysis Window by Suppressing Blood-Brain Barrier Disruption and Regulating Autophagy-Apoptosis Balance after Ischemic Stroke

BACKGROUND

Ischemic stroke (IS) is one of the leading causes of death and disability worldwide. The narrow therapeutic window (within 4.5 h) and severe hemorrhagic potential limits therapeutic efficacy of recombinant tissue type plasminogen activator (rt-PA) intravenous thrombolysis for patients. Xingnao Kaiqiao (XNKQ) acupuncture is an integral part of traditional Chinese medicine, specifically designed to address acute ischemic stroke by targeting key acupoints such as Shuigou (GV26) and Neiguan (PC6). In this study, we explored the therapeutic potential of XNKQ acupuncture in extending the time window for thrombolysis and interrogated the molecular mechanisms responsible for this effect.

METHODS

The effect of extending the thrombolysis window by acupuncture was evaluated via TTC staining, neuronal score evaluation, hemorrhagic transformation assay, and H&E staining. RNA sequencing (RNA-seq) technology was performed to identify the therapeutic targets and intervention mechanisms of acupuncture. Evans blue staining and transmission electron microscopy were used to assess blood-brain barrier (BBB) integrity. Immunofluorescence staining and co-immunoprecipitation were performed to evaluate the level of autophagy and apoptosis and validate their interactions with BBB endothelial cells.

RESULTS

Acupuncture alleviated infarction and neurological deficits and extended the thrombolysis window to 6 h. The RNA-seq revealed 16 potential therapeutic predictors for acupuncture intervention, which related to suppressing inflammation and restoring the function of BBB and blood vessels. Furthermore, acupuncture suppressed BBB leakage and preserved tight junction protein expression. The protective effect was associated with regulation of the autophagy-apoptosis balance in BBB endothelial cells. Acupuncture intervention dissociated the Beclin1/Bcl-2 complex, thereby promoting autophagy and reducing apoptosis.

CONCLUSION

XNKQ acupuncture could serve as an adjunctive therapy for rt-PA thrombolysis, aiming to extend the therapeutic time window and mitigate ischemia-reperfusion injury. Acupuncture suppressed BBB disruption by regulating the autophagy-apoptosis balance, which in turn extended the therapeutic window of rt-PA in IS. These findings provide a rationale for further exploration of acupuncture as a complementary candidate co-administered with rt-PA.

Hemorrhage induced by antithrombotic agents: new insights from a real-world pharmacovigilance study

BACKGROUND

Hemorrhage represents the most common and serious side effect of antithrombotic agents. Many studies have compared the risk of bleeding between different antithrombotic agents, but analysis of time-to-onset for hemorrhage induced by these drugs is yet sparse.

METHODS

We conducted a retrospective study based on the adverse drug reaction reports on antithrombotic agents collected by the Henan Adverse Drug Reaction Monitoring Center. We assessed the reporting odds ratio to determine the disproportionate reporting signals for bleeding and the Weibull shape parameter was used to evaluate the time-to-onset data.

RESULTS

In the signal detection, crude low molecular weight heparin-hemorrhage was found as a positive signal. The hemorrhage for most antithrombotic agents was random failure profiles. In particular, the hazard of hemorrhage decreased over time for warfarin and clopidogrel and increased for alteplase, nadroparin, and dipyridamole.

CONCLUSION

We found that the risk of bleeding in patients taking Crude low molecular weight heparins was significantly higher compared to other antithrombotic agents, but with a small magnificence, which may be attributed to the severely irrational use of this medication under improper management. Statistics in days, results showed that the risk of bleeding decreased over time for warfarin and clopidogrel and increased for alteplase, nadroparin, and dipyridamole.

Asymptomatic Intracerebral Hemorrhage Following Endovascular Stroke Therapy Is Not Benign: A Systematic Review and Meta-Analysis

BACKGROUND

Asymptomatic intracerebral hemorrhage (aICH) occurs in approximately 35% of patients with acute ischemic stroke after endovascular thrombectomy. Unlike symptomatic ICH, studies evaluating the effect of aICH on outcomes have been inconclusive. We performed a systematic review and meta-analysis to evaluate the long-term effects of postendovascular thrombectomy aICH.

METHODS AND RESULTS

The meta-analysis protocol was submitted to the International Prospective Register of Systematic Reviews a priori. PubMed, Scopus, and Web of Science were searched from inception through September 2023, yielding 312 studies. Two authors independently reviewed all abstracts. Included studies contained adult patients with ischemic stroke undergoing endovascular thrombectomy with follow-up imaging assessment of ICH reporting comparative outcomes according to aICH versus no ICH. After screening, 60 papers were fully reviewed, and 10 studies fulfilled inclusion criteria (n=5723 patients total, 1932 with aICH). Meta-analysis was performed using Cochrane RevMan v5.4. Effects were estimated by a random-effects model to estimate summary odds ratio (OR) of the effect of aICH versus no ICH on primary outcomes of 90-day modified Rankin Scale 3 to 6 and mortality. The presence of aICH was associated with a higher odds of 90-day mRS 3 to 6 (OR, 2.17 [95% CI, 1.81-2.60], P<0.0001, I2 46% Q 19.15) and mortality (OR, 1.72 [95% CI, 1.17-2.53], P:0.005, I2 79% Q 27.59) compared with no ICH. This difference was maintained following subgroup analysis according to hemorrhage classification and recanalization status.

CONCLUSIONS

The presence of aICH is associated with worse 90-day functional outcomes and higher mortality. Further studies to evaluate the factors predicting aICH and treatments aimed at reducing its occurrence are warranted.

Risk prediction models for intracranial hemorrhage in acute ischemic stroke patients receiving intravenous alteplase treatment: a systematic review

Objectives

To identify and compare published models that use related factors to predict the risk of intracranial hemorrhage (ICH) in acute ischemic stroke patients receiving intravenous alteplase treatment.

Methods

Risk prediction models for ICH in acute ischemic stroke patients receiving intravenous alteplase treatment were collected from PubMed, Embase, Web of Science, and the Cochrane Library up to April 7, 2023. A meta-analysis was performed using Stata 13.0, and the included models were evaluated using the Prediction Model Risk of Bias Assessment Tool (PROBAST).

Results

A total of 656 references were screened, resulting in 13 studies being included. Among these, one was a prospective cohort study. Ten studies used internal validation; five studies used external validation, with two of them using both. The area under the receiver operating characteristic (ROC) curve for subjects reported in the models ranged from 0.68 to 0.985. Common predictors in the prediction models include National Institutes of Health Stroke Scale (NIHSS) (OR = 1.17, 95% CI 1.09-1.25, p < 0.0001), glucose (OR = 1.54, 95% CI 1.09-2.17, p < 0.05), and advanced age (OR = 1.50, 95% CI 1.15-1.94, p < 0.05), and the meta-analysis shows that these are independent risk factors. After PROBAST evaluation, all studies were assessed as having a high risk of bias but a low risk of applicability concerns.

Conclusion

This study systematically reviews available evidence on risk prediction models for ICH in acute ischemic stroke patients receiving intravenous alteplase treatment. Few models have been externally validated, while the majority demonstrate significant discriminative power.