Prior Statin Use Reduces Mortality in Intracerebral Hemorrhage

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.

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.

Statins on Spontaneous Intracerebral Hemorrhage: A Meta-Analysis

Objective

In order to explore whether the application of statins can improve the prognosis of patients with intracerebral hemorrhage.

Methods

Studies of patients with intracerebral hemorrhage taking statins published in English until December 2021 were searched based on limited search terms, the retrieved literature was screened out based on inclusion and exclusion criteria, and the quality assessment and data extraction were carried out independently by two investigators. The extracted clinical data were then meta-analyzed.

Results

A total of 17 literatures were included in this study, with a sample size of 16,988 cases, including 3,001 cases in the statin group and 13,487 cases in the control group. MRS score of mortality was used as the prognostic index to evaluate cerebral hemorrhage. According to the Newcastle-Ottawa Scale (NOS), the score of literature quality evaluation scale was 6-8, indicating good literature quality. Meta-analysis of clinical data extracted from the literature showed that the statin group reduced overall mortality after intracerebral hemorrhage compared with the nonstatin group (P < 0.01). In terms of improving functional prognosis, the statin group improved functional prognosis 90 days after intracerebral hemorrhage (P=0.01). There was no significant difference between the statin and nonstatin groups in reducing the number of intracerebral hematomas.

Conclusions

Statins can reduce the total mortality after ICH and improve the survival rate (90 d), without increasing the amount of hematoma.

Oxidative Stress Following Intracerebral Hemorrhage: From Molecular Mechanisms to Therapeutic Targets

Intracerebral hemorrhage (ICH) is a highly fatal disease with mortality rate of approximately 50%. Oxidative stress (OS) is a prominent cause of brain injury in ICH. Important sources of reactive oxygen species after hemorrhage are mitochondria dysfunction, degradated products of erythrocytes, excitotoxic glutamate, activated microglia and infiltrated neutrophils. OS harms the central nervous system after ICH mainly through impacting inflammation, killing brain cells and exacerbating damage of the blood brain barrier. This review discusses the sources and the possible molecular mechanisms of OS in producing brain injury in ICH, and anti-OS strategies to ameliorate the devastation of 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.

Association of Statins With Functional Outcome and 30-Day Mortality in Patients With Intracerebral Hemorrhage

Aim

The effect of statins is well established in cardiac and cerebrovascular diseases. However, its impact on intracerebral hemorrhage (ICH) is unclear. We aim to identify an association of pre-ICH statin treatment and statin use during admission for ICH with functional outcome at discharge and 30-day mortality.

Material and methods

A retrospective cohort study was held in patients with ICH admitted to our stroke unit over a year period. Demographic characteristics, risk factors and cardiovascular diseases, Glasgow Coma Scale (GCS), National Institutes of Health Stroke Score (NIHSS), systolic blood pressure (SBP) at admission, cholesterol levels and radiologic findings were analyzed to explore the association between pre-ICH and inpatient statin use with outcomes. The primary endpoint was functional outcome defined as modified Rankin Score (mRS) at discharge and 30-day mortality. We performed a univariate analysis and the variables with statistical significance were included in a multivariate analysis to control for confounding covariates.

Results

The study included 78 patients, 33 (42.31%) had previous statin intake history, of which 13 (39.39%) maintained statin intake during hospitalization. Regarding functional outcome we did not report a statistically significant difference between groups. In the “pre-ICH statin use” group a decreased 30-day mortality (6.06%, p = 0.009) was observed. In this group it was also noted higher antiplatelet medication use (33.33%, p = 0.006), higher GCS at admission (13-15: 84.38%, p = 0.018) and deep ICH (81.82%, p = 0.030). However, 30-day mortality had no impact in multivariate regression (Odds ratio (OR) 4.535, 95% Confidence Interval (CI) = 0.786-26.173, p = 0.091). In the group that maintained statin treatment during hospitalization no deaths were registered (p = 0.020) and there was no association with functional status. Multivariate regression analysis was not performed due to sample size.

Conclusion

The only association demonstrated in this study was lower 30-day mortality with pre-ICH statin use and continued statin treatment during admission. However, this was not confirmed by multivariate regression analysis. There were no differences between groups concerning cholesterol values, results that can be explained by the pleiotropic and immunomodulatory effect of statins. However, prospective studies are needed to prove the benefit of the statins in ICH.

The Benefits and Risks of Statin Therapy in Ischemic Stroke: A Review of the Literature

Statins are effective cholesterol-lowering drugs for reducing the risks of mortality and morbidity of cardiovascular diseases. Increasing evidence has shown that statin use is associated with a significant beneficial effect in patients with ischemic stroke. Both pre-stroke and post-stroke statin use has been found to be beneficial in ischemic stroke. Furthermore, good adherence is associated with a better clinical outcome, and statin withdrawal is associated with a poor functional outcome in patients with ischemic stroke. High-intensity statin therapy is advocated for the treatment of ischemic stroke. However, there are concerns regarding the adverse effects associated with statin use in ischemic stroke such as intracranial hemorrhage. In this review, we summarize the beneficial effect of statin use in ischemic stroke and discuss the potential risks associated with statin therapy.

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.

Discontinuing or continuing statin following intracerebral hemorrhage from the view of a national cohort study

BACKGROUND AND AIMS

Statins improve clinical outcomes in patients with ischemic stroke but there is no evidence of the effect of continuing long-term statin therapy in patients with intracerebral hemorrhage (ICH). The aim of this study was to evaluate the impact of continuing statin after ICH.

METHODS

Data on patients with ICH was retrieved from the National Health Insurance Research Database of Taiwan. The final population was separated into two groups according to those who continued and those who discontinued statin treatment. All-cause mortality and cardiovascular outcomes were analyzed after a 3 year follow-up after propensity score matching (PSM).

RESULTS

Of the 114,101 patients with ICH, who were initially enrolled, 2468 patients with dyslipidemia and ICH were included. After PSM, the benefit of statin therapy on mortality appeared from 1 year to the end of the 3-year follow-up period after discharge (statin group versus non-statin group: 4.9% vs.12.3% at 1 year (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.26-0.57) and 12.9% vs. 25.3% at the end of the 3 year follow-up period (HR, 0.45; 95% CI, 0.35-0.58). Compared with the patients using lipophilic statins, those using hydrophilic statins had a significantly lower incidence of all-cause mortality (HR = 0.65, 95% CI = 0.43-0.99). There were no differences between those prescribed moderate-intensity statins and those prescribed high-intensity statins in terms of stroke and all-cause mortality (HR = 0.76; 95% CI = 0.40-1.46).

CONCLUSIONS

There was a lower risk of all-cause mortality following ICH in patients who continued statin treatment compared with those without statin treatment, especially in those treated with hydrophilic statins.

Phase II Clinical Trial of Atorvastatin in Mild Traumatic Brain Injury

Statins constitute a class of medications commonly used in the treatment of elevated cholesterol. However, in experimental studies, statins also have other non-cholesterol-mediated mechanisms of action, which may have neuroprotective effects. The aim of this study was to determine whether administration of atorvastatin for 7 days post-injury would improve neurological recovery in patients with mild traumatic brain injury (mTBI). The hypothesis was that atorvastatin administration would reduce post-concussion symptoms and also that atorvastatin administration for 1 week post-injury would be safe. One hundred forty patients with mTBI were planned to be enrolled and randomly assigned to receive atorvastatin 1 mg/kg (up to 80 mg/kg) per day or placebo for 7 days starting within 24 h of injury. Assessments of post-concussion syndrome, post-traumatic stress and depressive symptoms, cognition, memory, verbal fluency, functional, and work status were performed at baseline, 1 week, and 1 and 3 months. The result on the Rivermead Post-Concussion Symptoms Questionnaire at 3 months was the primary outcome. Enrollment in the trial was stopped early because of difficulty in recruiting sufficient numbers of subjects. Fifty-two patients with mTBI were enrolled; 28 patients received atorvastatin and 24 received placebo. The median Rivermead score was 2 for the atorvastatin group, compared to 3.5 for the placebo group, at 3 months post-injury (χ2(1) = 0.0976; p = 0.7547). The change in the Rivermead score between baseline and 3 months was also analyzed. The median decrease in score was 4 for the atorvastatin group and 10.5 for the placebo group (χ2(1) = 0.8750; p = 0.3496). No serious adverse events occurred, and there was no significant difference in the incidence of adverse events in the two treatment groups. Atorvastatin administration for 7 days post-injury was safe, but there were no significant differences in neurological recovery post-mTBI with atorvastatin.

Statins May Increase Intracerebral Hemorrhage Volume

Background:

Some studies have suggested an association between hypocholesterolemia and intracerebral hemorrhage (ICH). In the SPARCL trial, statin use increased ICH risk. We tested the hypothesis that use of statins affects the volume of spontaneous ICH and contributes to the progression of ICH volume between baseline and follow-up CT scans.

Methods:

Consecutive cases of spontaneous ICH were reviewed. Secondary causes were excluded. We measured ICH volume on the baseline and follow-up CT scans using the AxBxC/2 method. Multivariate analysis and logistic regression modeling were used. The primary outcome was the ICH volume on the baseline CT scan. Secondary outcomes included volume variation between the baseline and the first follow up CT scans and death.

Results:

Of 303 subjects, 71 were taking a statin at the time of the ICH (23%). Statin users were significantly more likely to be younger, to have co-morbidities and take anticoagulant or anti-platelet medication. They also had a higher baseline ICH volume than non-statin users (median 31.2 [10,82.1] ml vs 16 [4,43.8] ml; p=0.006). Adjusting for possible confounders, statins remained associated with an increased ICH volume (p=0.007). There was a significant mean ICH volume progression between the first and second CT scans in statin users (+10.8 vs +0.9 ml; p=0.03; 95% CI: [-1,+22.6] [-2.5,+4.3]). No difference in mortality was seen between the two groups.

Conclusion:

Treatment with HMG-CoA reductase inhibitors may be a risk factor for increased ICH volume in spontaneous brain hemorrhages and could contribute to hemorrhage's volume progression.

The Role of Statin Therapy in Hemorrhagic Stroke

The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are the most widely utilized class of cholesterol-lowering agents, carrying multiple indications for both primary and secondary cardiovascular risk reduction. Concern was raised by previously published post hoc analyses and observational studies that noted an increased risk of hemorrhagic stroke in patients receiving a statin. Subsequent studies have demonstrated conflicting results regarding the role of statin therapy on hemorrhagic stroke risk and patient outcomes. New evidence suggests that statins taken prior to or continued during admission for intracerebral hemorrhage (ICH) may be associated with positive outcomes. Evidence also suggests deleterious outcomes resulting from the abrupt discontinuation of statins upon hospital admission for multiple disease states including ICH. Conflicting data also exist for the use of statins following aneurysmal subarachnoid hemorrhage (aSAH). Recent evidence suggests statins started during admission for aSAH confer no additional benefit in reducing delayed ischemic neurologic deficits despite initial positive results. Larger scale evaluation of the role of statin therapy following hemorrhagic stroke is warranted. The available literature is reviewed to provide guidance for therapeutic decision making.

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.

Molecular, Cellular and Clinical Aspects of Intracerebral Hemorrhage: Are the Enemies Within?

Hemorrhagic stroke is a disease with high incidence and mortality rates. In addition to the mass lesions that result from hemorrhagic stroke, substances such as the blood-derived products (BDP) (hemoglobin (Hb), heme and iron) induce a potent inflammatory response and exert direct toxic effects on neurons, astrocytes, and microglia. In the present review, we discuss the mechanisms of brain injury secondary to hemorrhagic stroke, focusing on the involvement of BDP as major players of cellular redox imbalance, inflammation, and glutamate excitotoxicity. Potential natural mechanisms of protection against free Hb and heme such as haptoglobin and hemopexin, respectively, are highlighted. We finally discuss the experimental and clinical trials targeting free iron and heme scavenging as well as inflammation, as potential new therapies to minimize the devastating effects of hemorrhagic stroke on brain structure and function.

Meta-analysis of Statin Use for the Acute Therapy of Spontaneous Intracerebral Hemorrhage

BACKGROUND

Growing evidence demonstrates the neuroprotective effects of statins, and the risk to develop an intracerebral hemorrhage (ICH) using statins has been refuted. However, some controversy remains regarding their role in the acute phase after ICH onset. Therefore, we performed a systematic review to investigate this issue.

METHODS

We searched in MEDLINE, Web of Knowledge, and Scopus databases for studies examining the outcome in patients with spontaneous ICH and statin use. The analysis was performed for short-term (≤3 months) and long-term outcome (≥6 months) and a further subanalysis considered studies seeking for the effects of the discontinuation of statin after ICH onset. A random-effect model was applied, and country was used as a cofactor for meta-regression; odds ratios (ORs) with 95% confidence intervals (CIs) are offered.

RESULTS

A total of 17 studies were included, only 1 pseudo cohort trial assessed the new use of statin after ICH onset and 3 studies evaluated the suspension of statin after ICH onset, the rest of the studies focused on the effect of the regular use of statin before ICH onset. The number of patients with an ICH exposed and not exposed to statins were 3455 and 11,821, respectively. The absolute short-term mortality was 27.3% in statin users and 33% in nonusers that represented a significant risk reduction of mortality (OR, .73; 95% CI, .54-.97). For long-term mortality, the effect was less evident (OR, .71; 95% CI, .43-1.15). The analysis of the 3 studies assessing the discontinuation of statins suggested a reduction of mortality risk by continuing statin (OR, .14; 95% CI, .1-.20).

CONCLUSIONS

The current evidence suggests that continuing statin after ICH onset might be highly related to improvement of the outcome of patients with ICH. Despite this strong suggestion, randomized controlled trials should be performed to further investigate this association.

Statin use in spontaneous intracerebral hemorrhage: a systematic review and meta-analysis

BACKGROUND

Nonrandomized observational studies have been conducted to evaluate the effects of statins on clinical outcomes in patients with intracerebral hemorrhage. Several studies on the effects of statin administration in patients with intracerebral hemorrhage have been published recently, but the findings are inconsistent.

AIM

To evaluate the effects of statins administered prior to hospital admission and during hospitalization on mortality and functional outcomes in patients with intracerebral hemorrhage.

SUMMARY OF REVIEW

We searched for relevant literature using multiple comprehensive databases and performed a systematic review and meta-analysis. Sixteen studies met our selection criteria. Preintracerebral hemorrhage statin use was not associated with mortality (odds ratio: 0·90, 95% confidence interval: 0·63-1·28). However, patients who used statins prior to intracerebral hemorrhage had a decreased risk of mortality at three-months following symptom onset (odds ratio: 0·47, 95% confidence interval: 0·32-0·68) and an increased probability of good functional outcomes (odds ratio: 1·49, 95% confidence interval: 1·01-2·19), as compared with those who did not. In-hospital use of statins was associated with a low risk of mortality (odds ratio: 0·34, 95% confidence interval: 0·26-0·44) irrespective of preadmission statin use or postadmission time-points. Additionally, we were unable to pool the data on statin withdrawal because of differences in study methodologies.

CONCLUSIONS

Although careful interpretation is necessary due to several study limitations, we have demonstrated that statin use in patients with intracerebral hemorrhage is likely associated with improved mortality and functional outcomes.

Potential role of statins in the intracerebral hemorrhage and subarachnoid hemorrhage

Statins are used in primary and secondary prevention of cardiovascular episodes. Most of recent studies regard ischemic stroke. There are more emerging results of studies suggesting usefulness of these drugs in the other types of stroke e.g. intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH). Searching for new methods of treatment is important, because both ICH and SAH lead to poor prognosis and severe psychomotor disability. The unquestionable role of inflammatory factors in the pathogenesis of these disorders justifies considering statin treatment. Previous results are contradictory, thus in present study we review results of studies and try to explain the potential pathomechanism of statin use in hemorrhagic strokes.

No relationship of lipid-lowering agents to hematoma growth: pooled analysis of the intensive blood pressure reduction in acute cerebral hemorrhage trials studies

BACKGROUND AND PURPOSE

Controversy persists over statins and risk of intracerebral hemorrhage. We determined associations of premorbid lipid-lowering therapy and outcomes among participants of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trials (INTERACT).

METHODS

The pooled data of INTERACT 1 and 2 (international, multicenter, prospective, open, blinded end point, randomized controlled trials of patients with intracerebral hemorrhage [<6 hours] and elevated systolic blood pressure) were analyzed with regard to associations of baseline lipid-lowering treatment and clinical outcomes of 3184 participants in a multivariate model. Associations of lipid-lowering therapy and hematoma growth (baseline to 24 hours) in computed tomographic substudies participants (n=1310) were estimated in ANCOVA.

RESULTS

Among 204 patients (6.5%) with baseline lipid-lowering treatment, 90-day clinical outcomes were not significantly different after adjustment for confounding variables including region and age. In the computed tomographic substudy, 24-hour hematoma growth was greater in 124 patients (9%) with, compared with those without, prior lipid-lowering therapy. However, this association was not significant between groups (9.2 versus 6.8 mL; P<0.13), after adjustment for prior antithrombotic therapy.

CONCLUSIONS

No independent associations were found between lipid-lowering medication and adverse outcomes in patients with intracerebral hemorrhage.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00226096 and NCT00716079.

Use of statin during hospitalization improves the outcome after intracerebral hemorrhage

AIMS

To examine the relationship between statin use in Chinese patients with intracerebral hemorrhage (ICH) during their hospitalization and the outcomes.

METHODS

Data were collected from the China National Stroke Registry. Good functional outcome was defined by a modified Rankin Scale score between 0-2. Functional outcome and rate of mortality at 3 months and 1 year were compared between ICH patients on statin and those without it during their hospitalization. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated using the multivariable logistic regression model adjusted for baseline risk factors.

RESULTS

Among 3218 consecutive ICH patients from 2007 to 2008, 220 (6.8%) were on statin during their hospitalization. Compared with those without statin, patients on statin were younger, had more stroke risk factors but lower stroke severity. ICH patients on statin had better functional outcome at 3 months (OR 2.24, 95% CI 1.49-3.36) and at 1 year (OR 2.04, 95% CI 1.37-3.06). They also had lower rate of mortality at 3 months (OR 0.44, 95% CI 0.22-0.87) and 1 year (OR 0.49, 95% CI 0.27-0.86).

CONCLUSIONS

In-hospital statin use in ICH patients is associated with better functional outcome and lower mortality at 3 months and 1 year.

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.

Association between statin use and intracerebral hemorrhage: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Accumulating evidence suggests that statins exert neuroprotective effects, but whether their use affects the outcomes of intracerebral hemorrhage (ICH) remains controversial. Therefore, we performed a systematic review and meta-analysis to investigate whether statin use before spontaneous ICH affects unfavorable functional outcome or mortality.

METHODS

We searched the Cochrane Library, MEDLINE, EMBASE and China National Knowledge Infrastructure databases for studies examining the effects of pre-ICH statin use on unfavorable functional outcome, mortality or neuroimaging outcomes in consecutively recruited patients with spontaneous ICH, regardless of the duration or dose of statin treatment.

RESULTS

A total of 12 studies were included that examined the effects of pre-ICH statin use on post-ICH outcomes in 1652 subjects in the favors pre-statin group and 5309 in the favors no pre-ICH statin group. Meta-analysis of 11 studies suggested that pre-ICH statin use did not significantly affect mortality across all three time points tested [in-hospital, 30 days, 90 days; odds ratio (OR) 0.85, 95% confidence interval (CI) 0.70-1.03]. However, meta-analysis of seven studies showed that pre-ICH statin use did significantly decrease 90-day mortality (OR 0.72, 95% CI 0.59-0.88). Meta-analysis of six studies showed that pre-ICH statin use was not associated with significant changes in unfavorable functional outcome. Moreover, pre-ICH statin use did not significantly affect admission hematoma volume (standardized mean difference 7.75, 95% CI -5.59 to 21.09).

CONCLUSION

Available evidence suggests that statin use before spontaneous ICH does not increase short-term mortality, unfavorable functional outcome or post-ICH hematoma volume at admission.

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.

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.

Association of statins and statin discontinuation with poor outcome and survival after intracerebral hemorrhage

BACKGROUND AND PURPOSE

Studies suggest a protective role for statins after intracerebral hemorrhage, but many failed to assess statin discontinuation, did not include postdischarge outcomes, or did not account for withdrawal of care. We studied the relationship between preintracerebral hemorrhage statin use and in-hospital statin discontinuation on stroke severity and 30-day mortality.

METHODS

We analyzed data from the Registry of the Canadian Stroke Network and determined the adjusted ORs for statin use and outcomes, controlling for stroke severity and other covariates.

RESULTS

We analyzed 2466 consecutive patients with intracerebral hemorrhage from 2003 to 2008: median age was 71 years, 53.6% were male, and 30-day mortality rate was 36.5%. Overall, 537 (21.7%) were taking statins before presentation. Compared with nonusers, statin users were less likely to have severe strokes on presentation (54.7% versus 63.3%) but had similar rates of poor outcome (70% versus 67%) and 30-day mortality (36% versus 37%). Statins were discontinued on admission in 158 of 537 (29.4%); these patients were more likely to have severe stroke (65% versus 27%, P<0.01), poor outcome (90% versus 62%, P<0.01), and to have died by 30 days (71% versus 21%, P<0.01). After adjusting for stroke severity, statin discontinuation was still associated with poor outcome (adjusted OR, 2.4; 95% CI, 1.13-4.56) and higher mortality (adjusted OR, 2.0; 95% CI, 1.30-3.04). However, these associations were attenuated and no longer significant after excluding patients treated palliatively.

CONCLUSIONS

We found no association between preadmission statin use and outcomes in intracerebral hemorrhage. Statin discontinuation may worsen outcomes or may simply be a marker of worse underlying prognosis.

Prior use of 3-hydroxy-3-methyl-glutaryl-coenzyme a reductase inhibitor, simvastatin fails to improve outcome after experimental intracerebral hemorrhage

OBJECTIVE

Contrary to some clinical belief, there were quite a few studies regarding animal models of intracerebral hemorrhage (ICH) in vivo suggesting that prior use of statins may improve outcome after ICH. This study reports the effect of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG CoA) reductase inhibitor, simvastatin given before experimental ICH.

METHODS

Fifty-one rats were subjected to collagenase-induced ICH, subdivided in 3 groups according to simvastatin treatment modality, and behavioral tests were done. Hematoma volume, brain water content and hemispheric atrophy were analyzed. Immunohistochemical staining for microglia (OX-42) and endothelial nitric oxide synthase (eNOS) was performed and caspase-3 activity was also measured.

RESULTS

Pre-simvastatin therapy decreased inflammatory reaction and perihematomal cell death, but resulted in no significant reduction of brain edema and no eNOS expression in the perihematomal region. Finally, prior use of simvastatin showed less significant improvement of neurological outcome after experimental ICH when compared to post-simvastatin therapy.

CONCLUSION

The present study suggests that statins therapy after ICH improves neurological outcome, but prior use of statins before ICH might provide only histological improvement, providing no significant impact on neurological outcome against ICH.

Pleiotropic effects of the HMG-CoA reductase inhibitors

The HMG-CoA reductase inhibitors (statins) are used extensively in the treatment of hyperlipidemia. They have also demonstrated a benefit in a variety of other disease processes. These secondary actions are known as pleiotropic effects. Our paper serves as a focused and updated discussion on the pleiotropy of statins and emphasizes the importance of randomized placebo-controlled trials to further elucidate this interesting phenomenon.

Statin use and outcome after intracerebral hemorrhage: case-control study and meta-analysis

OBJECTIVES

Intracerebral hemorrhage (ICH) is a highly lethal disease of the elderly. Use of statins is increasingly widespread among the elderly, and therefore common in patients who develop ICH. Accumulating data suggests that statins have neuroprotective effects, but their association with ICH outcome has been inconsistent. We therefore performed a meta-analysis of all available evidence, including unpublished data from our own institution, to determine whether statin exposure is protective for patients who develop ICH.

METHODS

In our prospectively ascertained cohort, we compared 90-day functional outcome in 238 pre-ICH statin cases and 461 statin-free ICH cases. We then meta-analyzed results from our cohort along with previously published studies using a random effects model, for a total of 698 ICH statin cases and 1,823 non-statin-exposed subjects.

RESULTS

Data from our center demonstrated an association between statin use before ICH and increased probability of favorable outcome (odds ratio [OR] = 2.08, 95% confidence interval [CI] 1.37-3.17) and reduced mortality (OR = 0.47, 95% CI 0.32-0.70) at 90 days. No compound-specific statin effect was identified. Meta-analysis of all published evidence confirmed the effect of statin use on good outcome (OR = 1.91, 95% CI 1.38-2.65) and mortality (OR = 0.55, 95% CI 0.42-0.72) after ICH.

CONCLUSION

Antecedent use of statins prior to ICH is associated with favorable outcome and reduced mortality after ICH. This phenomenon appears to be a class effect of statins. Further studies are required to clarify the biological mechanisms underlying these observations.

Statin use following intracerebral hemorrhage: a decision analysis

CONTEXT

Statins are widely prescribed for primary and secondary prevention of ischemic cardiac and cerebrovascular disease. Although serious adverse effects are uncommon, results from a recent clinical trial suggested increased risk of intracerebral hemorrhage (ICH) associated with statin use. For patients with baseline elevated risk of ICH, it is not known whether this potential adverse effect offsets the cardiovascular and cerebrovascular benefits.

OBJECTIVE

To address the following clinical question: Given a history of prior ICH, should statin therapy be avoided?

DESIGN

A Markov decision model was used to evaluate the risks and benefits of statin therapy in patients with prior ICH.

MAIN OUTCOME MEASURE

Life expectancy, measured as quality-adjusted life-years. We investigated how statin use affects this outcome measure while varying a range of clinical parameters, including hemorrhage location (deep vs lobar), ischemic cardiac and cerebrovascular risks, and magnitude of ICH risk associated with statins.

RESULTS

Avoiding statins was favored over a wide range of values for many clinical parameters, particularly in survivors of lobar ICH who are at highest risk of ICH recurrence. In survivors of lobar ICH without prior cardiovascular events, avoiding statins yielded a life expectancy gain of 2.2 quality-adjusted life-years compared with statin use. This net benefit persisted even at the lower 95% confidence interval of the relative risk of statin-associated ICH. In patients with lobar ICH who had prior cardiovascular events, the annual recurrence risk of myocardial infarction would have to exceed 90% to favor statin therapy. Avoiding statin therapy was also favored, although by a smaller margin, in both primary and secondary prevention settings for survivors of deep ICH.

CONCLUSIONS

Avoiding statins should be considered for patients with a history of ICH, particularly those cases with a lobar location.

Clinicoradiological profile and serum lipid levels of intracerebral hemorrhage in prior statin users

OBJECTIVE

We aimed to evaluate whether serum lipid levels can influence the clinicoradiological recovery of intracerebral hemorrhage (ICH) in prior statin users.

PATIENTS AND METHODS

Medical records were reviewed retrospectively in 381 ICH patients (253 men and 128 women). Cardiovascular disease (CVD) risk factors, blood pressure at admission and the first in-hospital day, admission and 30-day scores of National Institute Health Stroke Scale (NIHSS) and modified Rankin scale (mRS), hematoma volume (HV), serum lipid levels were compared between prior statin users and non-users.

RESULTS

Statins were pretreated in 56 patients (31 men and 25 women). Statin users were older age, and had higher frequencies of dyslipidemia, diabetes mellitus, atrial fibrillation, prior stroke history and large HV compared to non-users. Serum levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly decreased in the statin group compared to the non-statin group. There were no statistical differences in the other CVD risk factors, functional scores and other serum lipid levels between the two groups. HV was correlated inversely with serum levels of TC and LDL-C in both groups. Multiple logistic regression analysis showed that serum TC levels ≤150 mg/dL were associated with statin use [Odds ratio (OR)=5.5, 95% confidence interval (CI)=1.55-19.58], worsening of NIHSS score (OR=1.4, 95% CI=1.21-1.63) and HV (OR=1.1, 95% CI=1.07-1.13) in ICH patients. A significant association was found between worsening of NIHSS score (OR=2.0, 95% CI=1.32-3.12) and worsening of mRS score (OR=3.3, 95% CI=1.33-8.00), HV (OR=1.3, 95% CI=1.01-1.76), and serum TC levels ≤150 mg/dL in statin users.

CONCLUSION

Prior statin users with serum TC levels ≤150 mg/dL had worsening of outcome and HV. Excessive lowering of serum TC levels due to statin pretreatment may cause unfavorable clinicoradiological recovery of ICH. Physicians should monitor serum lipid levels carefully in statin users.

Exploring neuroprotective drug therapies for intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating neurological disorder with high mortality and poor prognosis, for which virtually no effective drug therapies are available at present. Experimental animal models, based on intrastriatal injection of collagenase or autologous blood, have enabled great advances in elucidation of cellular/molecular events contributing to brain pathogenesis associated with ICH. Many lines of evidence indicate that blood constituents, including hemoglobin-derived products as well as proteases such as thrombin, play important roles in the pathogenic events. Inflammatory reactions involving neutrophils, activated microglia, and production of proinflammatory cytokines also constitute a critical aspect of pathology leading to neurodegeneration and tissue damage. Efforts are continuing to find drugs that potentially alleviate pathological and neurological outcomes of ICH. Various drugs that possess antioxidative, anti-inflammatory or neurotrophic/neuroprotective properties have been demonstrated to produce therapeutic effects on ICH animal models. Drugs already in clinical use such as minocycline, statins, and several nuclear receptor ligands are among the list of effective drugs, but whether they also show therapeutic efficacy in human ICH patients remains unproven. Here, current knowledge of ICH pathogenesis and problems arising with respect to exploration of new drug candidates are discussed.

Neuroprotective strategies for intracerebral hemorrhage: trials and translation

Intracerebral hemorrhage is a devastating neurological illness with few treatment options. In the past 10 years, 6 clinical trials have been completed examining the potential role that putative neuroprotective agents might play in improving outcome. Although each of these trials failed to show a benefit, animal research continues to supply the translational pipeline and 5 clinical trials evaluating neuroprotective agents in intracerebral hemorrhage are currently ongoing. Despite initial failures, neuroprotective agents continue to show promise in the treatment of intracerebral hemorrhage, but improvements in clinical trial design and more accurate predictive outcome models are necessary.

[Effect of the administration of statins in non-cardiac critical disease]

Administration of statins has been shown to be effective in reducing cardiovascular mortality. Their benefit could expand towards other areas of intensive medicine, it being possible to decrease mortality of the critically ill patient. There are several studies, although without a high level of evidence, that have detected a possible benefit when they are administered as well as clinical deterioration when they are discontinued, compared to those patients who had previously taken them. Even though most of the patients who had previously taken statins did so as primary or secondary prevention, thus having greater comorbidity, overall, a decrease is detected in the mortality of these subgroups. This benefit could be generalized to all the critical conditions, although studies with a higher level of evidence are needed for their adequate comparison.

Simvastatin improves clinical scores in a rabbit multiple infarct ischemic stroke model: synergism with a ROCK inhibitor but not the thrombolytic tissue plasminogen activator

Statins have pleiotropic neuroprotective effects in the central nervous system. In this study, we assessed the pharmacological effects of simvastatin on measures of behavior in New Zealand white rabbits embolized using a suspension of small-sized blood clots. For these studies, simvastatin was administered up to 3 hours following embolization, and behavior was measured 48 hours following embolization to calculate the dose of emboli (P(50) in mg) that produces neurological deficits in 50% of the rabbits. A treatment is considered neuroprotective if it significantly increases the P(50) compared to control. Simvastatin treatment (20mg/kg, bolus subcutaneous injection) significantly improved clinical function and increased the P(50) by 143% when administered 1 hour following embolization but was ineffective at 3 hours. In combination studies with the thrombolytic, tissue plasminogen activator (tPA) using a standard intravenous dose of 3.3mg/kg (20% bolus, 80% infused), we found that simvastatin could be safely administered with tPA to improve clinical scores; however, the maximum behavioral improvement with the combination treatment was similar to either monotherapy alone, both of which significantly improved behavior (p<0.05). It has been proposed that Simvastatin neuroprotection may be related to a variety of signaling pathways including Rho-kinase (ROCK). To determine if a ROCK mechanism is involved in simvastatin-induced neuroprotection following embolic strokes, we used pharmacological intervention with the ROCK inhibitor, fasudil. When fasudil was administered 30 minutes before simvastatin (given at 1 hour), there was an additional significant (p=0.0217) synergistic increase in behavioral function. However, fasudil as a monotherapy did not affect behavioral function in embolized rabbits. The study suggests that there may be an interaction between simvastatin treatment and the ROCK signaling pathway that should be further explored. Our results suggest that simvastatin treatment may have clinical benefit when used alone or in the presence of tPA, but the therapeutic window using a single-dose regimen is narrow.

Blood pressure treatment in acute ischemic stroke: a review of studies and recommendations

PURPOSE OF REVIEW

Elevated blood pressure (BP) is frequent in patients with acute ischemic stroke. Pathophysiological data support its usefulness to maintain adequate perfusion of the ischemic penumba. This review article aims to summarize the available evidence from clinical studies that examined the prognostic role of BP during the acute phase of ischemic stroke and intervention studies that assessed the efficacy of active BP alteration.

RECENT FINDINGS

We found 34 observational studies (33,470 patients), with results being inconsistent among the studies; most studies reported a negative association between increased levels of BP and clinical outcome, whereas a few studies showed clinical improvement with higher BP levels, clinical deterioration with decreased BP, or no association at all. Similarly, the conclusions drawn by the 18 intervention studies included in this review (1637 patients) were also heterogeneous. Very recent clinical data suggest a possible beneficial effect of early treatment with some antihypertensives on late clinical outcome.

SUMMARY

Observational and interventional studies of management of acute poststroke hypertension yield conflicting results. We discuss different explanations that may account for this and discuss the current guidelines and pathophysiological considerations for the management of acute poststroke hypertension.

Intracerebral hemorrhage: getting ready for effective treatments

PURPOSE OF REVIEW

Spontaneous intracerebral hemorrhage (ICH) is the most devastating type of stroke and a leading cause of disability and mortality in the United States and the rest of the world. The purpose of this article is to review recent advances in the management of spontaneous intracerebral hemorrhage.

RECENT FINDINGS

Although no interventions have consistently shown an improvement of mortality or functional outcomes after ICH, results from multicenter prospective randomized controlled trials have shown that early hemostasis to prevent hematoma growth, removal of clot by surgical or minimally invasive interventions, clearance of intraventricular hemorrhage, and adequate blood pressure control for the optimization of cerebral perfusion pressure may constitute the most important therapeutic goals to ameliorate secondary neurological damage, decrease mortality, and improve functional outcomes after ICH.

CONCLUSION

Several promising methods may be ready for routine clinical use in a few years to decrease disability and mortality from ICH.

Statins in traumatic brain injury

Traumatic brain injury (TBI) is a common cause of long-term neurological morbidity, with devastating personal and societal consequences. At present, no pharmacological intervention clearly improves outcomes, and therefore a compelling unmet clinical need remains. 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or "statins," offer a potential novel therapeutic strategy for TBI. Statins are well tolerated, easy to administer, and have a long clinical track record in critically ill patients. Their side effects are well defined and easily monitored. Preclinical studies have shown significant benefit of statins in models of TBI and related disease processes, including cerebral ischemia, intracerebral hemorrhage, and subarachnoid hemorrhage. In fact, multiple mechanisms have been defined by which statins may exert benefit after acute brain injury. Statins are currently positioned to be translated into clinical trials in acute brain injury and have the potential to improve outcomes after TBI.

Outcome of intracerebral haemorrhage patients pre-treated with statins

BACKGROUND

Statins treatment may have potential clinical impact in vascular disease beyond cholesterol lowering. Its benefits have been documented in cerebral ischaemia and in subarachnoid haemorrhage. In intracerebral haemorrhage (ICH), experimental models in statin-treated animals have better outcome than non-treated ones, but in humans the relationship is unclear. We investigated whether patients treated with statins before the onset of intracerebral haemorrhage have a better outcome at 3 months than patients without statins pre-treatment.

METHODS

Retrospective review of primary intracerebral haemorrhage case series from a prospective stroke register. We recorded demographics, vascular risk factors, previous statin treatment, Glasgow coma scale (GCS) at onset, ICH scale, hematoma volume and location, ventricular extension of the hematoma, and functional outcome at 3 months. The effect of prior statin treatment on good outcome (modified Rankin scale [mRS] 0 to 2) was analysed by logistic regression analysis.

RESULTS

We included 269 patients (age 71.9 +/- 12.4, mean +/- SD, 152 males). Thirty-four patients (12.6%) were on prior statin treatment when admitted. There were no differences in fasting serum cholesterol and triglycerides levels between the statin pre-treated groups and the group without statin pre-treatment. Multivariate regression analysis showed a significant association between age (OR: 0.95; CI 0.92-0.97), ICH volume (OR: 0.96; CI 0.94-0.98), GCS (OR: 1.55; CI 1.21-1.98), pre-treatment with statins (OR: 4.21; CI 1.47-12.17; P = 0.008), and good outcome at 3 months.

CONCLUSIONS

Statins pre-treatment of patients with intracerebral haemorrhage may provide better functional outcome at 3 months of acute onset.