Endovascular Therapy in Ischemic Stroke With Acute Large-Vessel Occlusion: Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism Japan Registry 2

Inhibition of NLRP3 Inflammasome: A Prospective Target for the Treatment of Ischemic Stroke

Stroke is one of the major devastating diseases with no effective medical therapeutics. Because of the high rate of disability and mortality among stroke patients, new treatments are urgently required to decrease brain damage following a stroke. In recent years, the inflammasome is a novel breakthrough point that plays an important role in the stroke, and the inhibition of inflammasome may be an effective method for stroke treatment. Briefly, inflammasome is a multi-protein complex that causes activation of caspase-1 and subsequent production of pro-inflammatory factors including interleukin (IL)-18 and IL-1β. Among them, the NLRP3 inflammasome is the most typical inflammasome, which can detect cell damage and mediate inflammatory response to tissue damage in ischemic stroke. The NLRP3 inflammasome has become a key mediator of post-ischemic inflammation, leading to a cascade of inflammatory reactions and cell death eventually. Thus, NLRP3 inflammasome is an ideal therapeutic target due to its important role in the inflammatory response after ischemic stroke. In this mini review article, we will summarize the structure, assembly, and regulation of NLRP3 inflammasome, the role of NLRP3 inflammasome in ischemic stroke, and several treatments targeting NLRP3 inflammasome in ischemic stroke. The further understanding of the mechanism of NLRP3 inflammasome in patients with ischemic stroke will provide novel targets for the treatment of cerebral ischemic stroke patients.

Clinical Outcome of Patients With Large Vessel Occlusion and Low National Institutes of Health Stroke Scale Scores

Background and Purpose—

The treatment and prognosis of acute large vessel occlusion with mild symptoms have not been sufficiently studied. The present study aimed to investigate the clinical or radiological predictors of clinical outcome in patients with stroke with mild symptoms due to acute large vessel occlusion.

Methods—

Of 2420 patients with acute large vessel occlusion in the RESCUE-Japan Registry 2 (Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism-Japan Registry 2), a multicenter prospective registry in Japan, patients with modified Rankin Scale scores of 0 to 2 before onset and initial National Institutes of Health Stroke Scale (NIHSS) scores of 0 to 5 were examined in post hoc analysis. We examined the clinical and radiological characteristics associated with a favorable outcome (modified Rankin Scale score, 0–2 at 90 days) using multivariate analysis, as well as the factors associated with a favorable outcome in patients treated with endovascular therapy.

Results—

We analyzed 272 patients (median age, 73 years; median NIHSS score on admission, 3). Eighty-six (31.6%) patients were treated with intravenous recombinant tissue-type plasminogen activator, 54 (19.9%) underwent endovascular therapy, and 208 (76.5%) showed a favorable outcome. In multivariate analysis, age <75 years (odds ratio [OR], 2.42 [95% CI, 1.30–4.50]), initial NIHSS score 0 to 3 (OR, 3.08 [95% CI, 1.59–5.98]), intravenous recombinant tissue-type plasminogen activator (OR, 2. 86 [95% CI, 1.32–6.21]), and blood glucose level ≤140 mg/dL (OR, 2.37 [95% CI, 1.22–4.60]) were independently associated with a favorable outcome. However, endovascular therapy was not associated with a favorable outcome (OR, 1.65 [95% CI, 0.71–3.88]). Among 54 patients treated with endovascular therapy, good reperfusion status was more common in the favorable outcome group (88.6% versus 60.0%; P <0.05).

Conclusions—

Younger age, lower initial NIHSS score, intravenous recombinant tissue-type plasminogen activator, and absence of hyperglycemia were independently associated with a favorable outcome in patients with acute large vessel occlusion with low NIHSS scores.

Registration—

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02419794.

Mitochondria as a therapeutic target for ischemic stroke

Stroke is the leading cause of death and physical disability worldwide. Mitochondrial dysfunction has been considered as one of the hallmarks of ischemic stroke and contributes to the pathology of ischemia and reperfusion. Mitochondria is essential in promoting neural survival and neurological improvement following ischemic stroke. Therefore, mitochondria represent an important drug target for stroke treatment. This review discusses the mitochondrial molecular mechanisms underlying cerebral ischemia and involved in reactive oxygen species generation, mitochondrial electron transport dysfunction, mitochondria-mediated regulation of inflammasome activation, mitochondrial dynamics and biogenesis, and apoptotic cell death. We highlight the potential of mitochondrial transfer by stem cells as a therapeutic target for stroke treatment and provide valuable insights for clinical strategies. A better understanding of the roles of mitochondria in ischemia-induced cell death and protection may provide a rationale design of novel therapeutic interventions in the ischemic stroke.

NLRP3 inflammasome in ischemic stroke: As possible therapeutic target

Inflammation is a devastating pathophysiological process during stroke, a devastating disease that is the second most common cause of death worldwide. Activation of the NOD-like receptor protein (NLRP3)-infammasome has been proposed to mediate inflammatory responses during ischemic stroke. Briefly, NLRP3 inflammasome activates caspase-1, which cleaves both pro-IL-1 and pro-IL-18 into their active pro-inflammatory cytokines that are released into the extracellular environment. Several NLRP3 inflammasome inhibitors have been promoted, including small molecules, type I interferon, micro RNAs, nitric oxide, and nuclear factor erythroid-2 related factor 2 (Nrf2), some of which are potentially efficacious clinically. This review will describe the structure and cellular signaling pathways of the NLRP3 inflammasome during ischemic stroke, and current evidence for NLRP3 inflammasome inhibitors.

Impact of Endovascular Therapy in Patients With Large Ischemic Core

Background and Purpose—

Endovascular therapy (EVT) is strongly recommended for acute cerebral large vessel occlusion with the Alberta Stroke Program Early CT Score (ASPECTS) ≥6 due to occlusion of the internal carotid artery or M1 segment of the middle cerebral artery. However, the effect of EVT for patients who have ischemic core with ASPECTS ≤5 (0–5) was not established. The purpose of this study was to elucidate the outcomes of EVT for patients with large ischemic core.

Methods—

Based on the data of The Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism Japan Registry 2, patients with internal carotid artery or M1 segment of the middle cerebral artery occlusion and pretreatment ASPECTS 0 to 5 on noncontrast CT or diffusion-weighted image were extracted, and the outcomes by EVT were analyzed. Primary end point was defined as a good functional outcome (modified Rankin Scale score of ≤2) after 90 days.

Result—

Among 2420 registered patients, 504 patients were with internal carotid artery or M1 segment of the middle cerebral artery occlusion and ASPECTS 0 to 5. Among these 504 patients, 172 (34.1 %) were treated with EVT (EVT group) and 332 (65.9 %) without (no-EVT group). In the no-EVT group, elderly patients, females, poor prestroke modified Rankin Scale, high National Institutes of Health Stroke Scale, low ASPECTS, and late admission were significantly more observed. Good functional outcomes were significantly more observed in the EVT group than in the no-EVT group (19.8 % versus 4.2 %; P <0.0001; adjusted odds ratio, 2.33; 95% CI, 1.10–4.94). The incidences of symptomatic intracranial hemorrhage within 72 hours did not significantly different between the EVT group and the no-EVT group (3.7 % versus 4.9%; P =0.55; adjusted odds ratio, 0.50; 95% CI, 0.14–1.73).

Conclusions—

Although outcomes in this group of patients were usually poor, the data suggested EVT may increase the likelihood of a good functional outcome.

Endovascular therapy for middle cerebral artery M2 segment occlusion: subanalyses of RESCUE-Japan Registry 2

OBJECTIVE

To compare the efficacy of endovascular therapy (EVT) with that of medical treatment in 'real-world 'patients with M2 occlusion.

METHODS

This was a post hoc analysis of the Recovery by Endovascular Salvage for Cerebral Ultra-acute Embolism Japan Registry 2. Among 2420 patients in the registry, we evaluated patients with isolated M2 occlusion and those with functional independence before the stroke. Multivariable logistic regression analysis was used to evaluate and compare clinical outcomes between EVT and medical treatment. Additional propensity score-matched (PSM) analyses were performed. We performed subgroup analyses of the primary outcome (modified Rankin Scale score 0-2 at 90 days) using forest plots of treatment effects.

RESULTS

Overall, 372 patients with M2 occlusion (n=184 EVT; n=188, medical treatment) were evaluated. The EVT group had a higher baseline National Institutes of Health Stroke Scale score (median (IQR), 15 [9-19] vs 10 [5-16]) and earlier onset to hospital door time (110 [50-258] vs 150 [60-343] min) than the medical treatment group. After adjustment, EVT was significantly associated with higher odds of primary outcome (adjusted OR=2.09; 95% CI 1.26 to 3.47) and lower odds of mortality at 90 days (adjusted OR= 0.27; 95% CI 0.08 to 0.93). After PSM analyses (184 patients were 1:1 matched with each group), EVT was effective and safe relative to medical treatment. Effects favoring EVT were present in several subgroups of interest.

CONCLUSION

In patients with M2 occlusion, our registry suggests that EVT is effective and safe.

Japanese Surveillance of Neuroendovascular Therapy in JR-NET - Part II. Japanese Registry of NeuroEndovascular Treatment 3. Main Report

This study, following Japanese Registry of NeuroEndovascular Treatment 1 and 2 (JR-NET 1 & 2), shows an annual trend of cases including adverse events and clinical outcomes at 30 days after NET. JR-NET3 was registered by 749 cumulative total number of physicians, certified by the Japanese Society of Neuroendovascular Therapy in 166 centers, between 2010 and 2014. Medical information about the patients was anonymized and retrospectively registered through a website. A total of 40,177 patients were recruited, 632 patients were excluded because data of preprocedural status were not available. So we analyzed 39,545 patients retrospectively. The proportion of octogenarians is increasing year-by-year and 14.7% in 2014 compared with 10.4% in 2010. Most frequent target disease is intracranial aneurysm. For the proportion of the treatment of intracranial aneurysm, 50.0% in 2010, but that has decreased to 44.8% in 2014. However, number of procedures were increased from 3150 in 2010 to 3419 in 2014. Although before the positive clinical evidence of mechanical thrombectomy for acute ischemic stroke (AIS) was established, the proportion of endovascular treatment for AIS increased 13.8% in 2014 compared with 6.3% in 2010. The number of patients requiring neuroendovascular treatment in Japan is increasing since 2010–2013, but that declined a little in 2014 caused by study operation suspended at the end of 2013. The outcomes of such therapy are clinically acceptable. Details of each type of treatment will be investigated in sub-analyses of the database.