Vascular recovery promoted by atorvastatin and simvastatin after experimental intracerebral hemorrhage: magnetic resonance imaging and histological study

Statins for neuroprotection in spontaneous intracerebral haemorrhage (STATIC): protocol for a multicentre, prospective and randomised controlled trial

INTRODUCTION

Intracerebral haemorrhage (ICH) is a neurological emergency with high morbidity and mortality, and current treatment is limited. Emerging evidence has reported that statins can exert neuroprotective effects in cerebrovascular diseases. However, most of the published clinical studies are retrospective. Therefore, it is important to conduct a prospective randomised controlled trial to further validate the efficacy and safety of statins in patients with ICH.

METHODS AND ANALYSIS

The present study is performed at Xuan Wu Hospital Capital Medical University, Beijing Fengtai You'anmen Hospital and Shunping County Hospital, Hebei Province. The target number of patients is 98. Eligible patients are randomly assigned in a 1:1 ratio to the statins group or the control group. The primary outcome is the perihaemorrhagic oedema to haematoma ratio at 7 days. Secondary outcomes include mortality at 30 days, haematoma resolution rate at 7 days, National Institute of Health stroke scale (NIHSS) score at 7 days or discharge, ordinal distribution of modified Rankin scale (mRS) score at 90 days, the proportion of patients with an mRS score of 0-2 on day 90, the proportion of patients with an mRS score of 0-3 on day 90, absolute haematoma volume changes between initial and 7-day follow-up CT scan, absolute perihaematomal oedema changes between initial and 7-day follow-up CT scan.

ETHICS AND DISSEMINATION

The trial has been approved by the ethics committees of Xuan Wu Hospital Capital Medical University, Beijing Fengtai You'anmen Hospital and Shunping County Hospital, Hebei Province. The results will be disseminated in a peer-reviewed journal and in conference reports.

TRIAL REGISTRATION NUMBER

NCT04857632.

Relationship between prior statin therapy and radiological features and clinical outcomes of intracerebral hemorrhage

OBJECTIVES

A post-hoc analysis of the ICH Deferoxamine (i-DEF) trial was performed to examine any associations pre-ICH statin use may have with ICH volume, PHE volume, and clinical outcomes.

MATERIALS AND METHODS

Baseline characteristics were assessed. Various ICH and PHE parameters were measured via a quantitative, semi-automated method at baseline and follow-up CT scans 72-96 h later. A multivariable logistic regression model was created, adjusting for the variables that were significantly different on univariable analyses (p < 0.05), to assess any associations between pre-ICH statin use and measures of ICH and PHE, as well as good clinical outcome (mRS ≤2), at 90 and 180 days.

RESULTS

262 of 291 i-DEF participants had complete data available for analysis. 69 (26.3 %) used statins prior to ICH onset. Pre-ICH statin users had higher prevalences of hypertension, diabetes, and prior ischemic stroke; higher concomitant use of antihypertensives and antiplatelets; and higher blood glucose level at baseline. On univariable analyses, pre-ICH statin users had smaller baseline ICH volume and PHE volume on repeat scan, as well as smaller changes in relative PHE (rPHE) volume and edema extension distance (EED) between the baseline and repeat scans. In the multivariable analysis, none of the ICH and PHE measures or good clinical outcome was significantly associated with pre-ICH statin use.

CONCLUSION

Pre-ICH statin use was not associated with measures of ICH or PHE, their growth, or clinical outcomes. These findings do not lend support to either overall protective or deleterious effects from statin use before or after ICH.

Neutrophil extracellular traps in intracerebral hemorrhage: implications for pathogenesis and therapeutic targets

Intracerebral hemorrhage is a common neurological disease, and its pathological mechanism is complex. As the first recruited leukocyte subtype after intracerebral hemorrhage, neutrophils play an important role in tissue damage. In the past, it was considered that neutrophils performed their functions through phagocytosis, chemotaxis, and degranulation. In recent years, studies have found that neutrophils also have the function of secreting extracellular traps. Extracellular traps are fibrous structure composed of chromatin and granular proteins, which plays an important role in innate immunity. Studies have shown a large number of neutrophil extracellular traps in hematoma samples, plasma samples, and drainage samples after intracerebral hemorrhage. In this paper, we summarized the related mechanisms of neutrophil external traps and injury after intracerebral hemorrhage. Neutrophil extracellular traps are involved in the process of brain injury after intracerebral hemorrhage. The application of related inhibitors to inhibit the formation of neutrophil external traps or promote their dissolution can effectively alleviate the pathological damage caused by intracerebral hemorrhage.

Statins and 90-Day Functional Performance and Survival in Patients with Spontaneous Intracerebral Hemorrhage

BACKGROUND

The neuroprotective effect of statins has become a focus of interest in spontaneous intracerebral hemorrhage (sICH). The purpose of this study was: (1) to evaluate the effect of statin use by the analyzed patients with sICH in the period preceding the onset of hemorrhage on their baseline neurological status and baseline neuroimaging of the head; (2) to evaluate the effect of statin use in the acute period of hemorrhage on the course and prognosis in the in-hospital period, taking into account whether the statin was taken before the hemorrhage or only after its onset; (3) to evaluate the effect of continuing statin treatment after in-hospital treatment on the functional performance and survival of patients up to 90 days after the onset of sICH symptoms, taking into account whether the statin was taken before the onset of sICH.

MATERIAL AND METHODS

A total of 153 patients diagnosed with sICH were analyzed, where group I were not previously taking a statin and group II were taking a statin before sICH onset. After lipidogram assessment, group I was divided into patients without dyslipidemia and without statin treatment (Ia) and patients with dyslipidemia who received de novo statin treatment during hospitalization (Ib). Group II patients continued taking statin therapy. We evaluated the effect of prior statin use on the severity of hemorrhage; the effect of statin use during the acute period of sICH on its in-hospital course; and the effect of statin treatment on the severity of neurological deficit, functional capacity and survival of patients up to 90 days after the onset of sICH symptoms.

RESULTS

There was no effect of prior statin use on the severity of hemorrhage as assessed clinically and by neuroimaging of the head. At in-hospital follow-up, subgroup Ia was the least favorable in terms of National Institutes of Health Stroke Scale (NIHSS) score. This subgroup had the highest percentage of deaths during hospitalization. In the post-hospital period, the greatest number of patients with improvement in the NIHSS, modified Rankin Scale (mRS) and Barthel scales were among those taking statins, especially group II patients. At 90-day follow-up, survival analysis fell significantly in favor of subgroup Ib and group II.

CONCLUSIONS

1. The use of statins in the pre-sICH period did not adversely affect the patients' baseline neurological status or the results of baseline neuroimaging studies. 2. Continued statin therapy prior to the onset of sICH or the inclusion of statins in acute treatment in patients with sICH and dyslipidemia does not worsen the course of the disease and the in-hospital prognosis. Statin therapy should not be discontinued during the acute phase of sICH. 3. To conclude the eventual beneficial effect on the functional performance and survival of patients after sICH onset, comparability of the analyzed groups in terms of clinical, radiological and other prognostic factors in spontaneous intracerebral hemorrhage would be needed. Future studies are needed to confirm these findings.

Atorvastatin combined with low-dose dexamethasone improves the neuroinflammation and survival in mice with intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a fatal disease with high mortality and poor prognosis that triggers multiple severe brain injuries associated with an inflammatory cascade response that cannot be treated with any effective medication. Atorvastatin (ATO) suppresses inflammation, alleviates brain trauma, and eliminates subdural hematoma. Dexamethasone (DXM) also has the capacity to inhibit inflammation. Thus, we combined ATO with low-dose DXM to treat ICH mice in vivo to examine whether the combined treatment can inhibit secondary inflammation around the cerebral hemorrhage and decrease overall mortality. Compared to the monotherapy by either ATO or DXM, the combined treatment significantly improves the survivorship of the ICH mice, accelerates their recovery of impaired neurological function, and modulates the circulating cytokines, oxidative products, and apoptosis. Moreover, the benefit of ATO-DXM combination therapy was most pronounced on day 3 after dosing compared to ATO or DXM alone. Thus, early administration of ATO combined with low-dose-DXM promotes better survival of ICH and improves neurological function by reducing neuroinflammation and brain edema in their early phase.

Prior statin and short-term outcomes of primary intracerebral hemorrhage: From a large-scale nationwide longitudinal registry

Introduction

The relationship between statins and intracerebral hemorrhage outcomes is unclear.

Aim

We aimed to compare the in‐hospital mortality and evacuation of intracranial hematoma rates in patients with primary intracerebral hemorrhage between prior statin users and nonusers.

Results

The final study population included 66,263 patients. Multivariable logistics analyses showed that prior statin use was not associated with in‐hospital mortality for primary intracerebral hemorrhage (adjusted odd ratio 0.78, 95% CI 0.61–1.01), but reduced the proportion of patients undergoing evacuation of intracranial hematoma (adjusted odd ratio 0.70, 95% CI 0.61–0.82). Propensity score matching analyses yielded similar results.

Conclusion

Prior statin use was not associated with in‐hospital mortality but did reduce evacuation of intracranial hematoma rates.

Central Nervous System Tissue Regeneration after Intracerebral Hemorrhage: The Next Frontier

Despite marked advances in surgical techniques and understanding of secondary brain injury mechanisms, the prognosis of intracerebral hemorrhage (ICH) remains devastating. Harnessing and promoting the regenerative potential of the central nervous system may improve the outcomes of patients with hemorrhagic stroke, but approaches are still in their infancy. In this review, we discuss the regenerative phenomena occurring in animal models and human ICH, provide results related to cellular and molecular mechanisms of the repair process including by microglia, and review potential methods to promote tissue regeneration in ICH. We aim to stimulate research involving tissue restoration after ICH.

Neuroprotective Therapies for Spontaneous Intracerebral Hemorrhage

Patients who survive the initial ictus of spontaneous intracerebral hemorrhage (ICH) remain vulnerable to subsequent injury of the perilesional parenchyma by molecular and cellular responses to the hematoma. Secondary brain injury after ICH, which contributes to long-term functional impairment and mortality, has emerged as an attractive therapeutic target. This review summarizes preclinical and clinical evidence for neuroprotective therapies targeting secondary injury pathways following ICH. A focus on therapies with pleiotropic antiinflammatory effects that target thrombin-mediated chemotaxis and inflammatory cell migration has led to studies investigating statins, anticholinergics, sphingosine-1-phosphate receptor modulators, peroxisome proliferator activated receptor gamma agonists, and magnesium. Attempts to modulate ICH-induced blood-brain barrier breakdown and perihematomal edema formation has prompted studies of nonsteroidal antiinflammatory agents, matrix metalloproteinase inhibitors, and complement inhibitors. Iron chelators, such as deferoxamine and albumin, have been used to reduce the free radical injury that ensues from erythrocyte lysis. Stem cell transplantation has been assessed for its potential to enhance subacute neurogenesis and functional recovery. Despite promising preclinical results of numerous agents, their outcomes have not yet translated into positive clinical trials in patients with ICH. Further studies are necessary to improve our understanding of the molecular events that promote damage and inflammation of the perihematomal parenchyma after ICH. Elucidating the temporal and pathophysiologic features of this secondary brain injury could enhance the clinical efficacy of neuroprotective therapies for ICH.

Redox Regulation of Microvascular Permeability: IL-1β Potentiation of Bradykinin-Induced Permeability Is Prevented by Simvastatin

Antioxidant effects of statins have been implicated in the reduction in microvascular permeability and edema formation in experimental and clinical studies. Bradykinin (Bk)-induced increases in microvascular permeability are potentiated by IL-1β; however, no studies have examined the protection afforded by statins against microvascular hyperpermeability. We investigated the effects of simvastatin pretreatment on albumin–fluorescein isothiocyanate conjugate (FITC-albumin) permeability in post-capillary venules in rat cremaster muscle. Inhibition of nitric oxide synthase with L-NAME (10µM) increased basal permeability to FITC-albumin, which was abrogated by superoxide dismutase and catalase. Histamine-induced (1 µM) permeability was blocked by L-NAME but unaffected by scavenging reactive oxygen species with superoxide dismutase (SOD) and catalase. In contrast, bradykinin-induced (1–100 nM) permeability increases were unaffected by L-NAME but abrogated by SOD and catalase. Acute superfusion of the cremaster muscle with IL-1β (30 pM, 10 min) resulted in a leftward shift of the bradykinin concentration–response curve. Potentiation by IL-1β of bradykinin-induced microvascular permeability was prevented by the nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) inhibitor apocynin (1 µM). Pretreatment of rats with simvastatin (5 mg·kg⁻¹, i.p.) 24 h before permeability measurements prevented the potentiation of bradykinin permeability responses by IL-1β, which was not reversed by inhibition of heme oxygenase-1 with tin protoporphyrin IX (SnPP). This study highlights a novel mechanism by which simvastatin prevents the potentiation of bradykinin-induced permeability by IL-1β, possibly by targeting the assembly of NADPH oxidase subunits. Our findings highlight the therapeutic potential of statins in the prevention and treatment of patients predisposed to inflammatory diseases.

PEGylation of Deferoxamine for Improving the Stability, Cytotoxicity, and Iron-Overload in an Experimental Stroke Model in Rats

Deferoxamine (DFO) is a widely used drug for the treatment of iron-overload-related diseases in the clinic. However, its inherent shortcomings, such as a short plasma half-life and cytotoxicity, need to be addressed to widen its clinical utility. In this study, PEGylated DFO was first synthesized, and its chemical structure was characterized, and then in vitro and in vivo studies were performed. The metabolism assay showed that the stability of the PEGylated DFO was significantly improved, with a half-life 20 times greater than DFO. Furthermore, the PEGylated DFO exhibited significantly lower cytotoxicity compared with DFO. Additionally, the hemocompatibility assay showed that the PEGylated DFO had no significant effect on the coagulation system, red blood cells, complement, and platelets. In vivo studies indicated that PEGylated DFO was capable of reducing the iron accumulation, degeneration of neurons, and promotion of functional recovery. Taken together, PEGylated DFO improved stability, cytotoxicity, and iron-overload in an experimental stroke model in rats, making it a promising therapy for treating iron-overload conditions in the clinic.

Nicotine promotes angiogenesis in mouse brain after intracerebral hemorrhage

Here we examined the effect of nicotine on angiogenesis in the brain after intracerebral hemorrhage (ICH), as angiogenesis is considered to provide beneficial effects on brain tissues during recovery from injury after stroke. Nicotine was administered to C57BL/6 mice suffering from collagenase-induced ICH in the striatum, either by inclusion in drinking water or by daily intraperitoneal injection. Nicotine administration by both routes enhanced angiogenesis within the hematoma-affected regions, as revealed by increased CD31-immunopositive area at 7 and 14 d after ICH. Double immunofluorescence histochemistry against CD31 and proliferating cell nuclear antigen revealed that nicotine increased the number of newly generated vascular endothelial cells within the hematoma. In spite of enhanced angiogenesis, nicotine did not worsen vascular permeability after ICH, as assessed by Evans Blue extravasation. These effects of nicotine were accompanied by an increased number of surviving neurons in the hematoma at 7 d after ICH. Unexpectedly, nicotine did not increase expression of vascular endothelial growth factor mRNA in the brain and did not enhance recruitment of endothelial progenitor cells from the bone marrow. These results suggest that nicotine enhances angiogenesis in the brain after ICH, via mechanisms distinct from those involved in its action on angiogenesis in peripheral tissues.

Significant reduction in the LDL cholesterol increases the risk of intracerebral hemorrhage: a systematic review and meta-analysis of 33 randomized controlled trials

The dose-dependent pleiotropic effects of statin therapy may have unwanted side effects such as increasing the risk of intracerebral hemorrhage (ICH). The relationships among statin therapy, LDL-cholesterol levels, and ICH risk remain controversial. Here, we conduct a systematic review and meta-analysis of dose-dependent statin therapy and ICH risk. Eligible articles were identified by searching MEDLINE from inception up to December 1, 2018. Reference lists of previous meta-analyses were manually searched to retrieve all relevant publications. Statin doses were allocated into one of two groups according to the observed reduction of LDL cholesterol: doses that lowered LDL-cholesterol levels ≥35% were regarded as high-dose statin therapy, whereas those that lowered LDL-cholesterol levels <35% were regarded as low-dose statin therapy. We retrieved 33 studies involving 203,305 subjects. The pooled analysis indicated that high-dose statin treatment significantly increased the risk of ICH [relative risk (RR), 1.35; 95% confidence interval (CI), 1.08-1.68] and reduced the risk of all stroke (RR, 0.85; 95% CI, 0.78-0.92), ischemic stroke (RR, 0.79; 95% CI, 0.72-0.87), and all-cause mortality (RR, 0.94; 95% CI, 0.90-0.98). The analyses did not detect any association between low-dose statin treatment and ICH (RR, 1.05; 95% CI, 0.88-1.25). Low-dose statin therapy significantly reduced the incidence of all stroke (RR, 0.84; 95% CI, 0.79-0.89), ischemic stroke (RR, 0.81; 95% CI, 0.76-0.86), and all-cause mortality (RR, 0.94; 95% CI, 0.92-0.97). Our data indicate that low-dose statin therapy is a safe and effective ICH treatment, whereas high-dose statin therapy is associated with increased ICH risk. Hence, our meta-analysis suggests that the dose-dependent pleiotropic effects of statin therapy are related to the measured reduction in LDL cholesterol.

Statins for neuroprotection in spontaneous intracerebral hemorrhage

Statins, a common drug class for treatment of dyslipidemia, may be neuroprotective for spontaneous intracerebral hemorrhage (ICH) by targeting secondary brain injury pathways in the surrounding brain parenchyma. Statin-mediated neuroprotection may stem from downregulation of mevalonate and its derivatives, targeting key cell signaling pathways that control proliferation, adhesion, migration, cytokine production, and reactive oxygen species generation. Preclinical studies have consistently demonstrated the neuroprotective and recovery enhancement effects of statins, including improved neurologic function, reduced cerebral edema, increased angiogenesis and neurogenesis, accelerated hematoma clearance, and decreased inflammatory cell infiltration. Retrospective clinical studies have reported reduced perihematomal edema, lower mortality rates, and improved functional outcomes in patients who were taking statins before ICH. Several clinical studies have also observed lower mortality rates and improved functional outcomes in patients who were continued or initiated on statins after ICH. Subgroup analysis of a previous randomized trial has raised concerns of a potentially elevated risk of recurrent ICH in patients with previous hemorrhagic stroke who are administered statins. However, most statin trials failed to show an association between statin use and increased hemorrhagic stroke risk. Variable statin dosing, statin use in the pre-ICH setting, and selection biases have limited rigorous investigation of the effects of statins on post-ICH outcomes. Future prospective trials are needed to investigate the association between statin use and outcomes in ICH.

Role of Regulatory T cells in Atorvastatin Induced Absorption of Chronic Subdural Hematoma in Rats

Chronic subdural hematoma (CSDH) is a neurological disorder with a substantial recurrence rate. Atorvastatin is an effective drug for treating hyperlipidemia and known to improve neurological outcome after intracerebral hemorrhage. Previous studies have reported that atorvastatin treatment promotes hematoma absorption in CSDH, while the underlying mechanisms remain unclear. In this study, we investigated whether the anti-inflammatory effects of atorvastatin mediate absorption of CSDH. 144 male, Wistar rats (6 months old) were randomly divided into the following groups: 1) sham surgery control, 2) treatment: CSDH + atorvastatin, and 3) vehicle control: CSDH + saline. Atorvastatin or saline was orally administered daily for 19 days after CSDH procedure. A T2WI MRI was used to evaluate CSDH volume changes during the time course of the study. Flow cytometry and immunohistochemical staining were used to measure the number of regulatory T cells (Treg). ELISA was used to measure cytokine level in the hematoma border. Neurological function and cognitive outcome were evaluated using Foot-Fault test and Morris Water Maze test, respectively. When compared to saline treatment, atorvastatin treatment accelerated the absorption of CSDH as indicated by decreased hematoma volume in T2WI MRI data on 14^th and 21^st day after CSDH (P<0.05). Atorvastatin treatment significantly increased the number of Treg in circulation and hematoma border from 3^rd to 21^st day after CSDH. Atorvastatin treatment significantly decreased the levels of interleukins (IL-6 and IL-8) and tumor necrosis factor-α (TNF-α), but increased IL-10 level in the hematoma border. Atorvastatin treatment also improved neurological function and cognitive outcome compared to vehicle treated group. Atorvastatin induced anti-inflammatory responses and increased Treg in circulation and brain which may contribute to the accelerated CSDH absorption in rats.

Simvastatin improves cerebrovascular injury caused by ischemia‑reperfusion through NF‑κB‑mediated apoptosis via MyD88/TRIF signaling

Cerebrovascular injury is the most prevalent human cerebrovascular disease and frequently results in ischemic stroke. Simvastatin may be a potential therapeutic agent for the treatment of patients with cerebrovascular injury. The present study aimed to investigate the efficacy of and the potential mechanisms regulated by simvastatin in a rat model of ischemia-reperfusion (I/R)-induced cerebrovascular injury. Cerebrovascular injury model rats were established and were subsequently treated with simvastatin or a vehicle control following I/R injury. Cell damage, neurological functions and neuronal apoptosis were examined, as well as the nuclear factor (NF)-κB-mediated myeloid differentiation primary response protein 88 (MyD88)/toll-interleukin-1 receptor domain-containing adapter molecule 1 (TRIF) signaling pathway following simvastatin treatment. The results of the present study demonstrated that simvastatin treatment led to a reduction in cell damage, improvement of neurological functions and decreased neuronal apoptosis compared with vehicle-treated I/R model rats, 14 days post-treatment. In addition, simvastatin treatment reduced cerebral water content and blood-brain barrier disruption in cerebrovascular injury induced by I/R. The results also revealed that simvastatin treatment inhibited neuronal apoptosis via the NF-κB-mediated MyD88/TRIF signaling pathway. In conclusion, simvastatin treatment may reduce I/R-induced neuronal apoptosis via inhibition of the NF-κB-mediated MyD88/TRIF signaling pathway.

Simvastatin improves intracerebral hemorrhage through NF-κB-mediated apoptosis via the MyD88/TRIF signaling pathway

The aim was to investigate the neuroprotective effects and potential mechanism mediated by simvastatin in a mouse model of intracerebral hemorrhage. CD-1 mice were subjected to infusion of collagenase type IV into the left striatum in order to induce intracerebral hemorrhage. Western blot analysis, the TUNEL assay and the modified neurological severity score were used in the present study to analyze the efficacy of simvastatin for intracerebral hemorrhage. The results demonstrated that simvastatin treatment improved the cerebral water content and blood-brain barrier disruption in the intracerebral hemorrhage animals. Intracerebral hemorrhage-induced neuronal cell death was downregulated by simvastatin treatment compared with the vehicle-treated model group. In addition, the expression levels of aquaporin-4, matrix metallopeptidase 9 and caspase-3 were downregulated and B-cell lymphoma-2 was upregulated by simvastatin treatment compared with the vehicle-treated model. Simvastatin treatment also significantly reduced the Evans blue leakage into the injured hemispheres and improved motor function. Mechanism analysis further indicated that simvastatin treatment downregulated nuclear factor (NF)-κB expression, and upregulated the myeloid differentiation primary response 88 (MyD88) and TIR domain-containing adaptor protein inducing interferon-β (TRIF) expression levels in neuronal cells in experimental mice. Furthermore, the results revealed that NF-κB overexpression abolished the simvastatin-downregulated MyD88 and TRIF expression levels, as well as the apoptosis of neuronal cells. In conclusion, these results indicated that simvastatin was able to attenuate brain edema and reduce cellular apoptosis by suppressing the NF-κB-mediated MyD88/TRIF signaling pathway subsequent to the induction of intracerebral hemorrhage in mice.

Use of Statins and Outcomes in Intracerebral Hemorrhage Patients

BACKGROUND AND PURPOSE

Statin use may be associated with improved outcome in intracerebral hemorrhage patients. However, the topic remains controversial. Our analysis examined the effect of prior, continued, or new statin use on intracerebral hemorrhage outcomes using the ERICH (Ethnic/Racial Variations of Intracerebral Hemorrhage) data set.

METHODS

We analyzed ERICH (a multicenter study designed to examine ethnic variations in the risk, presentation, and outcomes of intracerebral hemorrhage) to explore the association of statin use and hematoma growth, mortality, and 3-month disability. We computed subset analyses with respect to 3 statin categories (prior, continued, or new use).

RESULTS

Two thousand four hundred and fifty-seven enrolled cases (mean age, 62 years; 42% females) had complete data on mortality and 3-month disability (modified Rankin Scale). Among those, 1093 cases were on statins (prior, n=268; continued, n=423; new, n=402). Overall, statin use was associated with reduced mortality and disability without any effect on hematoma growth. This association was primarily driven by continued/new statin use. A multivariate analysis adjusted for age and major predictors for poor outcome showed that continued/new statins users had good outcomes compared with prior users. However, statins may have been continued/started more frequently among less severe patients. When a propensity score was developed based on factors that could influence a physician's decision in prescribing statins and used as a covariate, continued/new statin use was no longer a significant predictor of good outcome.

CONCLUSIONS

Although statin use, especially continued/new use, was associated with improved intracerebral hemorrhage outcomes, this effect may merely reflect the physician's view of a patient's prognosis rather than a predictor of survival.

Intracerebral Hemorrhage: Perihemorrhagic Edema and Secondary Hematoma Expansion: From Bench Work to Ongoing Controversies

Intracerebral hemorrhage (ICH) is a medical emergency, which often leads to severe disability and death. ICH-related poor outcomes are due to primary injury causing structural damage and mass effect and secondary injury in the perihemorrhagic region over several days to weeks. Secondary injury after ICH can be due to hematoma expansion (HE) or a consequence of repair pathway along the continuum of neuroinflammation, neuronal death, and perihemorrhagic edema (PHE). This review article is focused on PHE and HE and will cover the animal studies, related human studies, and clinical trials relating to these mechanisms of secondary brain injury in ICH patients.

A Prospective Safety Trial of Atorvastatin Treatment to Assess Rebleeding after Spontaneous Intracerebral Hemorrhage: A Serial MRI Investigation

AIM

This study was designed to determine any rebleeding after atorvastatin treatment following spontaneous intracerebral hemorrhage (ICH) in a prospective safety trial.

PATIENTS

Atorvastatin (80 mg/day) therapy was initiated in 6 patients with primary ICH with admission Glasgow Coma Score (GCS) >5 within 24 hours of ictus and continued for 7 days, with the dose tapered and treatment terminated over the next 5 days. Patients were studied longitudinally by multiparametric magnetic resonance imaging (MRI) at three time points: acute (3 to 5 days), subacute (4 to 6 weeks) and chronic (3 to 4 months). Imaging sequences included T₁, T₂-weighted imaging (T₂WI), diffusion tensor imaging (DTI) and contrast-enhanced MRI measures of cerebral perfusion, blood volume and blood-brain barrier (BBB) permeability. Susceptibility weighted imaging (SWI) was used to identify primary ICH and to check for secondary rebleeding. Final outcome was assessed using Glasgow Outcome Score (GOS) at 3-4 months.

RESULTS

Mean admission GCS was 13.2±4.0 and mean GOS at 3 months was 4.5±0.6. Hemorrhagic lesions were segmented into core and rim areas. Mean lesion volumes decreased significantly between the acute and chronic study time points (p=0.008). Average ipsilateral hemispheric tissue loss at 3 to 4 months was 11.4±4.6 cm³. MRI showed acutely reduced CBF (p=0.004) and CBV (p=0.002) in the rim, followed by steady normalization. Apparent diffusion coefficient of water (ADC) in the rim demonstrated no alterations at any of the time points (p>0.2). The T₂ values were significantly elevated in the rim acutely (p=0.02), but later returned to baseline. The ICH core showed sustained low CBF and CBV values concurrent with a small reduction in ADC acutely, but significant ADC elevation at the end suggestive of irreversible injury.

CONCLUSION

Despite the presence of a small, probably permanent, cerebral lesion in the ICH core, no patients exhibited post-treatment rebleeding. These data suggest that larger, Phase 2 trials are warranted to establish long term clinical safety of atorvastatin in spontaneous ICH.

Statins in Intracerebral Hemorrhage

While statins play an indisputable role in primary and secondary prevention of ischemic cardiovascular and cerebrovascular disease, a concern exists regarding a possible association between low lipoprotein levels and statin use on the risk of intracerebral hemorrhage (ICH). While these data may incline physicians to discontinue statins after ICH, an increasing amount of preclinical and clinical evidence suggests that statins might have a beneficial effect on outcome and recovery in this context that goes beyond lipid lowering effects. Different etiologies of ICH and the related risk of recurrence should also be taken into account when deciding about statin use/avoidance in patients with high risk of ICH. The problem is compounded by paucity of data from randomized controlled trials and well-designed prospective observational studies. This review will discuss the existing evidence on potential interactions between statins and risk of ICH as well as outcomes in order to provide practical recommendations for clinical decision-making.

Water Exchange across the Blood-Brain Barrier in Obstructive Sleep Apnea: An MRI Diffusion-Weighted Pseudo-Continuous Arterial Spin Labeling Study

BACKGROUND AND PURPOSE

Obstructive sleep apnea (OSA) subjects show brain injury in sites that control autonomic, cognitive, and mood functions that are deficient in the condition. The processes contributing to injury may include altered blood-brain barrier (BBB) actions. Our aim was to examine BBB function, based on diffusion-weighted pseudo-continuous arterial spin labeling (DW-pCASL) procedures, in OSA compared to controls.

METHODS

We performed DW-pCASL imaging in nine OSA and nine controls on a 3.0-Tesla MRI scanner. Global mean gray and white matter arterial transient time (ATT, an index of large artery integrity), water exchange rate across the BBB (Kw, BBB function), DW-pCASL ratio, and cerebral blood flow (CBF) values were compared between OSA and control subjects.

RESULTS

Global mean gray and white matter ATT (OSA vs. controls; gray matter, 1.691 ± .120 vs. 1.658 ± .109 second, P = .49; white matter, 1.700 ± .115 vs. 1.650 ± .114 second, P = .44), and CBF values (gray matter, 57.4 ± 15.8 vs. 58.2 ± 10.7 ml/100 g/min, P = .67; white matter, 24.2 ± 7.0 vs. 24.6 ± 6.7 ml/100 g/min, P = .91) did not differ significantly, but global gray and white matter Kw (gray matter, 158.0 ± 28.9 vs. 220.8 ± 40.6 min(-1) , P = .002; white matter, 177.5 ± 57.2 vs. 261.1 ± 51.0 min(-1) , P = .006), and DW-pCASL ratio (gray matter, .727 ± .076 vs. .823 ± .069, P = .011; white matter, .722 ± .144 vs. .888 ± .100, P = .004) values were significantly reduced in OSA over controls.

CONCLUSIONS

OSA subjects show compromised BBB function, but intact large artery integrity. The BBB alterations may introduce neural damage contributing to abnormal functions in OSA, and suggest a need to repair BBB function with strategies commonly used in other fields.

Emerging experimental therapies for intracerebral hemorrhage: targeting mechanisms of secondary brain injury

Intracerebral hemorrhage (ICH) is associated with a higher degree of morbidity and mortality than other stroke subtypes. Despite this burden, currently approved treatments have demonstrated limited efficacy. To date, therapeutic strategies have principally targeted hematoma expansion and resultant mass effect. However, secondary mechanisms of brain injury are believed to be critical effectors of cell death and neurological outcome following ICH. This article reviews the pathophysiology of secondary brain injury relevant to ICH, examines pertinent experimental models, and highlights emerging therapeutic strategies. Treatment paradigms discussed include thrombin inhibitors, deferoxamine, minocycline, statins, granulocyte-colony stimulating factors, and therapeutic hypothermia. Despite promising experimental and preliminary human data, further studies are warranted prior to effective clinical translation.

Long-term improvement in outcome after intracerebral hemorrhage in patients treated with statins

BACKGROUND

Intracerebral hemorrhage (ICH) is a severe type of stroke for which there is currently no specific medical therapy. We hypothesized that statins reduce immediate inflammatory injury and improve long-term recovery from increased neurogenesis and angiogenesis. We conducted a large retrospective cohort study to assess the influence of statin therapy on patient death and disability at 12 months after ICH.

METHODS

This was a retrospective analysis of a prospectively collected database at a tertiary care medical center. Patients were grouped based on statin use, and poor outcome was assessed as dead or alive with dependency (modified Barthel Index≤14).

RESULTS

We compared outcomes in 190 patients exposed to statins to 236 patients who were not exposed to statins. Univariate analysis found that statin use was associated with decreased mortality in-hospital and at 12 months (P=.001). Multivariable analysis found that statin use was associated with a decreased odds of death or disability at 12 months after ICH (odds ratio 0.44; 95% confidence interval 0.21-0.95).

CONCLUSIONS

Statin use is associated with improved long-term outcome at 12 months after ICH. This finding supports previous clinical studies that have shown the short-term benefits of statin therapy. In addition, this study correlates with animal studies supporting the possible long-term recovery benefits of statins.

Strategies of clopidogrel load and atorvastatin reload to prevent ischemic cerebral events in patients undergoing protected carotid stenting. Results of the randomized ARMYDA-9 CAROTID (Clopidogrel and Atorvastatin Treatment During Carotid Artery Stenting) study

OBJECTIVES

This study sought to evaluate whether a strategy with a 600-mg clopidogrel load and a short-term, high-dose atorvastatin reload would improve outcomes in clopidogrel-naïve, statin-treated patients undergoing protected carotid stenting.

BACKGROUND

Optimal clopidogrel loading dose during carotid stenting has not been investigated; in addition, statin neuroprotection in this setting has not been described.

METHODS

A total of 156 patients were randomized using a 2 × 2 factorial design to receive either a 600-mg (n = 78) or 300-mg (n = 78) clopidogrel load given 6 h before intervention and either a atorvastatin reload (n = 76; 80 mg + 40 mg initiating 12 h before the procedure) or no statin reload (n = 80). The primary endpoint was the 30-day incidence of transient ischemic attack/stroke or new ischemic lesions on cerebral diffusion-weighted magnetic resonance imaging performed at 24 to 48 h.

RESULTS

Occurrence of the primary outcome measure was significantly lower in the 600-mg clopidogrel arm (18% vs. 35.9% in the 300-mg group; p = 0.019) and in the atorvastatin reload arm (18.4% vs. 35.0% in the no statin reload group; p = 0.031). High-dose clopidogrel also significantly reduced the transient ischemic attack/stroke rate at 30 days (0% vs. 9%, p = 0.02, secondary endpoint), without an increase in bleeding risk.

CONCLUSIONS

In patients undergoing carotid stenting, a strategy using both a 600-mg clopidogrel load and a short-term reload with high-dose atorvastatin protects against early ischemic cerebral events. These results, obtained along with routine mechanical neuroprotection, provide new evidence of the optimization of drug therapy before percutaneous carotid intervention. (Clopidogrel and Atorvastatin Treatment During Carotid Artery Stenting [ARMYDA-9 CAROTID]; NCT01572623).

Statins Protect the Blood Brain Barrier Acutely after Experimental Intracerebral Hemorrhage

OBJECTIVES

The goal of this study was to measure the impact of simvastatin and atorvastatin treatment on blood brain barrier (BBB) integrity after experimental intracerebral hemorrhage (ICH).

METHODS

Primary ICH was induced in 27 male Wistar rats by stereotactic injection of 100 µL of autologous blood into the striatum. Rats were divided into three groups (n= 9/group): 1) oral treatment (2 mg/kg) of atorvastatin, 2) oral treatment (2 mg/kg) simvastatin, or 3) phosphate buffered saline daily starting 24-hours post-ICH and continuing daily for the next 3 days. On the fourth day, the animals underwent magnetic resonance imaging (MRI) for measurements of T_1sat (a marker for BBB integrity), T₂ (edema), and cerebral blood flow (CBF). After MRI, the animals were sacrificed and immunohistology or Western blotting was performed.

RESULTS

MRI data for animals receiving simvastatin treatment showed significantly reduced BBB dysfunction and improved CBF in the ICH rim compared to controls (P<0.05) 4 days after ICH. Simvastatin also significantly reduced edema (T₂) in the rim at 4 days after ICH (P<0.05). Both statin-treated groups demonstrated increased occludin and endothelial barrier antigen levels within the vessel walls, indicating better preservation of BBB function (P<0.05) and increased number of blood vessels (P<0.05).

CONCLUSIONS

Simvastatin treatment administered acutely after ICH protects BBB integrity as measured by MRI and correlative immunohistochemistry. There was also evidence of improved CBF and reduced edema by MRI. Conversely, atorvastatin showed a non-significant trend by MRI measurement.

Short-term high-dose effect of lovastatin on thrombolysis by rt-PA in a human whole-blood in vitro clot model

High-dose hydroxymethylglutaryl coenzyme. A reductase inhibitor (statin) administration reduces neuronal injury and improves outcomes in experimental models of acute ischemic stroke, and has been shown to be safe in a phase 1 dose-escalation study using lovastatin at doses higher than currently approved for daily use. Statins also affect the hemostatic system by upregulating t-PA expression and decreasing plasminogen activator inhibitor (PAI-1) expression, platelet adhesion and thrombus formation in animal models. Since a thrombolytic agent, recombinant tissue plasminogen activator (rt-PA), is currently the only FDA-approved therapy for use in ischemic stroke patients, it is important to ascertain whether high statin doses impact the efficacy of rt-PA. The main goal of this study was to evaluate the effect of a high dose of lovastatin and its active form, lovastatin hydroxy acid, on rt-PA thrombolysis in an in vitro model. Percentage clot lysis was measured in the presence and absence of rt-PA in three different treatment groups: lovastatin, lovastatin hydroxy acid, and ethanol. The effect of ethanol on clot lysis was studied since ethanol was used to disperse the highly hydrophobic lovastatin. The decrease in clot width over time was measured using microscopic imaging of an in vitro human whole blood clot model; an approximately 400 μm diameter clot was formed on suture silk, suspended in human fresh frozen plasma (hFFP) and exposed to treatment. In the absence of rt-PA, clot lysis did not show statistically significant differences in the percentage clot lysis between different treatment groups (p=0.103). In the presence of rt-PA, clot lysis was greater than in the absence of rt-PA for all groups, but there were no statistically significant differences between treatment groups (p=0.385). In this in vitro study, high doses of lovastatin neither impaired nor enhanced the lytic efficacy of rt-PA.

Acute Statin Treatment Improves Recovery after Experimental Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

We have previously demonstrated that 2-week treatment of experimental intracerebral hemorrhage (ICH) with a daily dose of 2 mg/kg statin starting 24 hours post-injury exerts a neuroprotective effect. The present study extends our previous investigation and tests the effect of acute high-dose (within 24 hours) statin therapy on experimental ICH.

MATERIAL AND METHODS

Fifty-six male Wistar rats were subjected to ICH by stereotactic injection of 100 μl of autologous blood into the striatum. Rats were divided randomly into seven groups: saline control group (n = 8); 10, 20 and 40 mg/kg simvastatin-treated groups (n = 8); and 10, 20 and 40 mg/kg atorvastatin-treated groups (n = 8). Simvastatin or atorvastatin were administered orally at 3 and 24 hours after ICH. Neurological functional outcome was evaluated using behavioral tests (mNSS and corner turn test) at multiple time points after ICH. Animals were sacrificed at 28 days after treatment, and histological studies were completed.

RESULTS

Acute treatment with simvastatin or atorvastatin at doses of 10 and 20 mg/kg, but not at 40 mg/kg, significantly enhanced recovery of neurological function starting from 2 weeks post-ICH and persisting for up to 4 weeks post ICH. In addition, at doses of 10 mg/kg and 20 mg/kg, histological evaluations revealed that simvastatin or atorvastatin reduced tissue loss, increased cell proliferation in the subventricular zone and enhanced vascular density and synaptogenesis in the hematoma boundary zone when compared to saline-treated rats.

CONCLUSIONS

Treatment with simvastatin or atorvastatin at doses of 10 and 20 mg/kg significantly improves neurological recovery after administration during the first 24 hours after ICH. Decreased tissue loss, increased cell proliferation and vascularity likely contribute to improved functional recovery in rats treated with statins after ICH.

Statins improve outcome in murine models of intracranial hemorrhage and traumatic brain injury: a translational approach

Traumatic brain injury (TBI) and intracerebral hemorrhage (ICH) are leading causes of neurological mortality and disability in the U.S. However, therapeutic options are limited and clinical management remains largely supportive. HMG-CoA reductase inhibitors (statins) have pleiotropic mechanisms of action in the setting of acute brain injury, and have been demonstrated to improve outcomes in preclinical models of ICH and TBI. To facilitate translation to clinical practice, we now characterize the optimal statin and dosing paradigm in murine models of ICH and TBI. In a preclinical model of TBI, mice received vehicle, simvastatin, and rosuvastatin at doses of 1 mg/kg and 5 mg/kg for 5 days after the impact. Immunohistochemistry, differential gene expression, and functional outcomes (rotarod and Morris water maze testing) were assessed to gauge treatment response. Following TBI, administration of rosuvastatin 1 mg/kg was associated with the greatest improvement in functional outcomes. Rosuvastatin treatment was associated with histological evidence of reduced neuronal degeneration at 24 h post-TBI, reduced microgliosis at day 7 post-TBI, and preserved neuronal density in the CA3 region at 35 days post-injury. Administration of rosuvastatin following TBI was also associated with downregulation of inflammatory gene expression in the brain. Following ICH, treatment with simvastatin 1 mg/kg was associated with the greatest improvement in functional outcomes, an effect that was independent of hemorrhage volume. Clinically relevant models of acute brain injury may be used to define variables such as optimal statin and dosing paradigms to facilitate the rational design of pilot clinical trials.

Statins Enhance Expression of Growth Factors and Activate the PI3K/Akt-mediated Signaling Pathway after Experimental Intracerebral Hemorrhage

Previous studies have demonstrates that statins improve neurological outcome and promote neurovascular recovery after ICH. This study is designed to examine whether simvastatin and atorvastatin affect levels of growth factors and activate the Akt signaling pathway during the recovery phase after intracerebral hemorrhage (ICH) in rats. Sixty (60) male Wistar rats were subjected to ICH by stereotactic injection of 100 μL of autologous blood into the striatum and were treated with or without simvastatin or atorvastatin. Neurological functional outcome was evaluated by behavioral tests (mNSS and corner turn test) at different time points after ICH. Brain extracts were utilized for Enzyme-linked immunosorbent assay (ELISA) analyses to measure vascular endothelial growth factor (VEGF); brain-derived neurotrophin factor (BDNF) expression, and nerve growth factor (NGF). Western blot was used to measure the changes in the Akt-mediated signaling pathway. Both the simvastatin- and atorvastatin-treated animals had significant neurological improvement at 2 weeks post-ICH. Simvastatin and atorvastatin treatment increased the expression of BDNF, VEGF and NGF in both low- and high-dose groups at 7 days after ICH (p < 0.05). Phosphorylation of Akt, glycogen synthase kinase-3β (GSK-3β), and cAMP response element-binding proteins (CREB) were also increased at 7 days after statin treatment. These results suggest that the therapeutic effects of statins after experimental ICH may be mediated by the transient induction of BDNF, VEGF and NGF expression and the activation of the Akt-mediated signaling pathway.

Comparison of different preclinical models of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is the most devastating type of stroke. It is characterized by spontaneous bleeding in brain parenchyma and is associated with a high rate of morbidity and mortality. Presently, there is neither an effective therapy to increase survival after intracerebral hemorrhage nor a treatment to improve the quality of life for survivors. A reproducible animal model of spontaneous ICH mimicking the development of acute and delayed brain injury after ICH is an invaluable tool for improving our understanding of the underlying mechanisms of ICH-induced brain injury and evaluating potential therapeutic interventions. A number of models have been developed. While different species have been studied, rodents have become the most popular and widely utilized animals used in ICH research. The most often used methods for experimental induction of ICH are injection of bacterial collagenase and direct injection of blood into the brain parenchyma. The "balloon" method has also been used to mimic ICH for study. In this summary, we intend to provide a comparative overview of the technical methods, aspects, and pathologic findings of these types of ICH models. We will also focus on the similarities and differences among these rodent models, achievements in technical aspects of the ICH model, and discuss important aspects in selecting relevant models for study.