Remote Ischemic Conditioning With Medical Management or Reperfusion Therapy for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Remote ischemic conditioning in experimental hepatic ischemia‑reperfusion: A systematic review and meta‑analysis

Remote ischemic conditioning (RIC), including pre-conditioning (RIPC, before the ischemic event), per-conditioning (RIPerC, during the ischemic event), and post-conditioning (RIPostC, after the ischemic event), protects the liver in animal hepatic ischemia-reperfusion injuries models. However, several questions regarding the optimal timing of intervention and administration protocols remain unanswered. Therefore, the preclinical evidence on RIC in the HIRI models was systematically reviewed and meta-analyzed in the present review to provide constructive and helpful information for future works. In the present review, 39 articles were identified by searching the PubMed, OVID, Web of Science and Embase databases spanned from database inception to July 2024. According to the preferred reporting items for systematic reviews and meta-analyses guidelines, data were extracted independently by two researchers. The primary outcomes evaluated in this study were those directly related to liver injury, such as alanine transaminase (ALT), aspartate transaminase (AST) and liver histopathology. The risk of bias was assessed using the risk of bias tool of the SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE). The findings were expressed as standardized mean difference (SMD) and analyzed using random-effects models. Egger's test was used to evaluate the publication bias. RIC significantly reduced the changes in ALT, AST and liver histopathology (all P<0.00001). These effects had two peaks, with the first peak of RIPerC/RIPostC occurring earlier, regardless of models and species. RIPerC/RIPostC exerted significant effects on changes in ALT and AST [ALT SMD (95% confidence interval (CI]): RIPC -1.97 (-2.40, -1.55) vs. -2.78 (-3.77, -1.78); P=0.142; AST SMD (95%CI): RIPC -1.45 (-1.90, -0.99) vs. -2.13 (-2.91, -1.34); P=0.142], and RIPC had a greater effect on liver histopathology change [SMD (95%CI): RIPC -2.68 (-3.67, -1.69) vs. -1.58 (-2.24, -0.92); P=0.070]; however, no interactions were observed between the two groups in the meta-regression analysis. RIC is the most effective in experimental HIRI, using a 10-25-min dose. These outcomes suggest that RIC may be a promising strategy for treating HIRI; however, future studies using repeated doses in animal models with comorbidities will present novel ideas for its therapeutic application. The protocol of present study was registered with PROSPERO (CRD42023482725).

Safety and Efficacy of Remote Ischemic Conditioning in Patients With Intravenous Thrombolysis: The SERIC-IVT Trial

BACKGROUND

Approximately half of the patients with acute ischemic stroke who receive intravenous thrombolysis (IVT) do not achieve an excellent outcome. Remote ischemic conditioning (RIC) as a promising neuroprotective treatment may improve clinical outcomes in this population. This study aimed to assess the efficacy and safety of RIC in patients with IVT.

METHODS

This multicenter, participant-blinded, blinded end point, randomized controlled clinical trial included 558 patients with acute ischemic stroke who underwent IVT in 18 hospitals from August 2021 to May 2023. After IVT, patients were randomized 1:1 to the RIC (unilateral upper limb; cuff pressure, 200 mm Hg, twice daily for 7 days) or sham RIC groups (the same procedure; cuff pressure, 60 mm Hg). The primary efficacy outcome was an excellent functional outcome (modified Rankin Scale score, 0-1) at 90 days after IVT.

RESULTS

In total, 558 eligible patients were randomized, and 11 (2.0%) were excluded because they did not receive an RIC or sham RIC. Thus, 547 patients (RIC, n=274; sham RIC, n=273) were included in the modified intention-to-treat analysis, of whom 15 patients were lost to follow-up and 532 (95.3%) completed the trial. At 90 days, 62.7% of patients in the RIC group and 56.8% in the sham RIC group had an excellent functional outcome (unadjusted risk ratio, 1.10 [95% CI, 0.96-1.27]; P=0.169). The proportion of patients with any adverse events was 11.2% in the RIC group and 8.1% in the sham RIC group, with no significant difference (P=0.221).

CONCLUSIONS

RIC was safe in patients with acute ischemic stroke who received IVT. However, it did not significantly improve excellent functional outcome.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04980625.

Interfacility Transfer for Thrombectomy: A Promising Therapeutic Window

Currently, most acute ischemic stroke patients presenting with a large vessel occlusion are first evaluated at a nonthrombectomy-capable center before transfer to a comprehensive stroke center that performs thrombectomy. Interfacility transfer is a complex process that requires extensive coordination between the referring, transporting, and receiving facilities. As a result, long delays are common, contributing to poor clinical outcomes. In this review, we summarize the accumulating literature about the clinical as well as radiological-infarct growth, collateral change, arterial recanalization, and hemorrhagic transformation-changes during interfacility transfer for thrombectomy. Recent evidence shows that clinical/radiological changes during transfer are heterogeneous across patients and impact long-term functional outcomes, highlighting the urgent need to optimize care during this time window. We review some of the most promising therapeutic strategies-for example, penumbral protection to reduce infarct growth-that may improve clinical outcome in patients being transferred to thrombectomy-capable centers. Finally, we discuss key methodological considerations for designing clinical trials aimed at reducing infarct growth during transfer.

Evaluating the Usability of a Remote Ischemic Conditioning Device for Pre-Hospital Stroke Management: Insights from Paramedic Simulations

BACKGROUND/OBJECTIVES

In acute stroke, often-prolonged hospital transport times present an opportunity for early interventions to salvage brain tissue. Remote ischemic conditioning (RIC), where brief cycles of ischemia-reperfusion in a limb are induced to protect the brain, is a promising treatment for this setting. We assessed the usability of a novel RIC system in a simulated emergency response scenario.

METHODS

Paramedics were asked to use the RIC device in an emergency stroke care and ambulance transport simulation, overseen by a confederate. Feedback on device use was collected through questionnaires, including the System Usability Scale (SUS) and the NASA Task Load Index (NASA-TLX), and a semi-structured interview. Questionnaire responses were summarized using descriptive statistics; interview transcripts were analyzed thematically.

RESULTS

Nine paramedics (including the confederate) participated, with a mean of 10.0 ± 10.3 years of professional experience. Questionnaire responses indicated high device usability (mean SUS score: 85.3 ± 12.9 out of 100) and low task-related demands, effort, and frustration (mean NASA-TLX domain scores: ≤3.9 out of 20). Seven paramedics stated they would use the device in daily practice. They expressed concerns related to display screen clarity, interference with standard procedures, cable management, device fragility, and patient discomfort. Suggested improvements included adding indicators of device performance and refining the cuff design.

CONCLUSIONS

While the device was considered easy to use, paramedics also identified important areas of improvement. With a small, localized study sample, our findings are primarily applicable to the refinement of the RICovery system for use in future clinical trials in the same healthcare setting. However, feedback on the importance of mitigating potential interference of newly introduced procedures with those already established, robustness of equipment, and effective paramedic-patient communication may also help inform the design of other pre-hospital interventions.

Effects and mechanisms of long-acting glucagon-like peptide-1 receptor agonist semaglutide on microglia phenotypic transformation and neuroinflammation after cerebral ischemia/reperfusion in rats

BACKGROUND

The optimal method for addressing cerebral ischemic stroke involves promptly restoring blood supply. However, cerebral ischemia-reperfusion injury (CIRI) is an unavoidable consequence of this event. Neuroinflammation is deemed the primary mechanism of CIRI, with various activation phenotypes of microglia playing a pivotal role. Research has demonstrated that long-lasting agonists of the glucagon-like peptide-1 receptor can suppress neuroinflammation and microglial activation.

METHODS

A transient middle cerebral artery occlusion (tMCAO) rat model was established to investigate the effects of semaglutide. Neurological impairments were evaluated utilizing modified neurological severity score on days 1, 3, and 7 postinterventions. Brains were stained with 2,3,5-Triphenyltetrazolium Chloride to determine infarct volume. To assess the expression of various microglia activation phenotypes and neuroinflammatory biomarkers, we utilized immunohistochemistry and immunoblotting.

RESULTS

The study demonstrated that semaglutide in the tMCAO model could decrease neurological deficit scores and reduce the size of cerebral infarcts. In addition, we observed low levels of cluster of differentiation 68 (CD68, an indicator of M1 microglial activation) and tumor necrosis factor alpha (a pro-inflammatory mediator). Moreover, the results indicated a rise in the levels of CD206 (an indicator of M2 activation) and transforming growth factor beta (an anti-inflammatory mediator), while simultaneously reducing P65 levels in the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling cascade.

CONCLUSION

In the CIRI model, semaglutide exhibits notable neuroprotective effects on rats, reducing neuroinflammation through the regulation of microglia phenotype transformation and inhibition of NF-κB activation.