What is the value of conducting a trial of r-tPA for the treatment of mild stroke patients?

Updates of the role of B-cells in ischemic stroke

Ischemic stroke is a major disease causing death and disability in the elderly and is one of the major diseases that seriously threaten human health and cause a great economic burden. In the early stage of ischemic stroke, neuronal structure is destroyed, resulting in death or damage, and the release of a variety of damage-associated pattern molecules induces an increase in neuroglial activation, peripheral immune response, and secretion of inflammatory mediators, which further exacerbates the damage to the blood-brain barrier, exacerbates cerebral edema, and microcirculatory impairment, triggering secondary brain injuries. After the acute phase of stroke, various immune cells initiate a protective effect, which is released step by step and contributes to the repair of neuronal cells through phenotypic changes. In addition, ischemic stroke induces Central Nervous System (CNS) immunosuppression, and the interaction between the two influences the outcome of stroke. Therefore, modulating the immune response of the CNS to reduce the inflammatory response and immune damage during stroke is important for the protection of brain function and long-term recovery after stroke, and modulating the immune function of the CNS is expected to be a novel therapeutic strategy. However, there are fewer studies on B-cells in brain function protection, which may play a dual role in the stroke process, and the understanding of this cell is still incomplete. We review the existing studies on the mechanisms of the role of B-cells, inflammatory response, and immune response in the development of ischemic stroke and provide a reference for the development of adjuvant therapeutic drugs for ischemic stroke targeting inflammatory injury.

Comparing the Effectiveness of Intravenous Tissue Plasminogen Activator and Dual Antiplatelet Therapy in Patients With Minor Stroke: A Meta-Analysis

The aim of this study was to compare the outcomes between dual antiplatelet therapy (DAPT) versus intravenous tissue plasminogen activator (IV t-PA) in patients with minor stroke. This meta-analysis follows the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Two authors independently conducted online database searches using PubMed, Web of Science, and EMBASE to identify articles published in English language from inception to September 5, 2023. Outcomes assessed in this meta-analysis included all-cause mortality, stroke incidence, and functional outcomes (measured by modified ranking scale (mRS) scores of 0 to 1). A total of three studies fulfilled the eligibility criteria and included in the final analysis. Pooled analysis showed that the risk of all-cause mortality was not significantly different between the t-PA group and DAPT group (relative risk (RR): 1.14, 95% confidence interval (CI): 0.32-4.06). Compared with those treated with DAPT, there was no significant difference in t-PA in terms of the number of patients with a favorable functional outcome (defined as an mRS score of 0-1). The risk of stroke was not significantly different between the t-PA group and DAPT group (RR: 1.11, 95% CI: 0.68 to 1.82). The analysis, based on three studies, revealed no significant differences between t-PA and DAPT regarding all-cause mortality, stroke incidence, and functional outcomes.

Comparison of outcome of patients with acute minor ischaemic stroke treated with intravenous t-PA, DAPT or aspirin

Background

Whether to treat minor stroke with intravenous tissue plasminogen activator (t-PA) treatment or antiplatelet therapy is a dilemma. Our study aimed to explore whether intravenous t-PA treatment, dual antiplatelet therapy (DAPT) and aspirin have different efficacies on outcomes in patients with minor stroke.

Methods

A post hoc analysis of patients with acute minor stroke treated with intravenous t-PA within 4.5 hours from a nationwide multicentric electronic medical record and patients with acute minor stroke treated with DAPT and aspirin from the Clopidogrel with Aspirin in Acute Minor Stroke or Transient Ischemic Attack Database. Minor stroke was defined by a score of 0–3 on the National Institutes of Health Stroke Scale at randomisation. Favourable functional outcome (defined as modified Rankin Scale (mRS) score of 0–1 or 0–2 at 3 months).

Results

Compared with those treated with intravenous t-PA, no significant association with 3-month favourable functional outcome (defined as mRS score of 0–1) was found neither in patients treated with aspirin (87.8% vs 89.4%; OR, 0.83; 95% CI, 0.46 to 1.50; p=0.53) nor those treated with DAPT (87.4% vs 89.4%; OR, 0.84; 95% CI, 0.46 to 1.52; p=0.56). Similar results were observed for the favourable functional outcome defined as mRS score of 0–2 at 3 months.

Conclusions

In our study, no significant advantage of intravenous t-PA over DAPT or aspirin was found. Due to insufficient sample size, our study is probably unable to draw such a conclusion that that intravenous t-PA was superior or non-superior to DAPT.

Hydrogen inhibits microglial activation and regulates microglial phenotype in a mouse middle cerebral artery occlusion model

Microglia participate in bi-directional control of brain repair after stroke. Previous studies have demonstrated that hydrogen protects brain after ischemia/reperfusion (I/R) by inhibiting inflammation, but the specific mechanism of anti-inflammatory effect of hydrogen is poorly understood. The goal of our study is to investigate whether inhalation of high concentration hydrogen (HCH) is able to attenuate I/R-induced microglia activation. Eighty C57B/L male mice were divided into four groups: sham, I/R, I/R + HCH and I/R + N₂/O₂ groups. Assessment of animals happened in “blind” matter. I/R was induced by occlusion of middle cerebral artery for one hour). After one hour, filament was withdrawn, which induced reperfusion. Hydrogen treated I/R animals inhaled mix of 66.7% H₂ balanced with O₂ for 90 minutes, starting immediately after initiation of reperfusion. Control animals (N₂/O₂) inhaled mix in which hydrogen was replaced with N₂ for the same time (90 minutes). The brain injury, such as brain infarction and development of brain edema, as well as neurobehavioral deficits were determined 23 hours after reperfusion. Effect of HCH on microglia activation in the ischemic penumbra was investigated by immunostaining also 23 hours after reperfusion. mRNA expression of inflammation related genes was detected by PCR. Our results showed that HCH attenuated brain injury and consequently reduced neurological dysfunction after I/R. Furthermore, we demonstrated that HCH directed microglia polarization towards anti-inflammatory M2 polarization. This study indicates hydrogen may exert neuroprotective effects by inhibiting the microglial activation and regulating microglial polarization. This study was conducted in agreement with the Animal Care and Use Committee (IACUC) and Institutional Animal Care guidelines regulation (Shanghai Jiao Tong University, China (approval No. A2015-011) in November 2015.

Thrombolysis After Protamine Reversal of Heparin for Acute Ischemic Stroke After Cardiac Catheterization: Case Report and Literature Review

BACKGROUND

Patients with an acute ischemic stroke (AIS) following cardiac catheterization (CC) generally do not receive intravenous thrombolysis [intravenous tissue plasminogen activator (IV-tPA)] as it is contraindicated due to the coagulopathy related to the heparin used during the procedure. We report a case of AIS successfully treated with IV thrombolysis following protamine reversal of heparin effect.

CASE REPORT

An 87-year-old man with diabetes mellitus, hypertension, neurofibromatosis, and hyperlipidemia underwent elective transradial CC following an abnormal stress test. He had 2 drug-eluting stents for severe stenosis of mid-circumflex and right coronary arteries and received heparin 13,000 IU during procedure. He developed acute left hemiparesis with initial NIH stroke scale (NIHSS) of 4. Computed tomographic scan of the brain and computed tomographic angiogram of head and neck were unremarkable. Bedside activated clotting time was 181. Protamine 40 mg was administered and 30 minutes later, the activated clotting time level was normalized. IV-tPA was administered at 4 hours 25 minutes from his last known well. Within 15 minutes, his NIHSS was 0. Magnetic resonance imaging of brain showed no acute infarction 24 hours after stroke.

CONCLUSIONS

There are limited reports of protamine reversal of heparin before IV-tPA administration. To our knowledge, there are only 6 AIS cases including ours. Three cases received 0.6 mg/kg of tPA dose. All have favorable outcomes and no intracranial hemorrhage was reported. Protamine reversal of heparin for AIS after CC seems to be safe. Further studies are needed to confirm the therapeutic safety and efficacy of this strategy.