Does pretreatment with statins improve clinical outcome after stroke? A pilot case-referent study

Charge effect of a liposomal delivery system encapsulating simvastatin to treat experimental ischemic stroke in rats

BACKGROUND AND AIMS

Although the beneficial effects of statins on stroke have been widely demonstrated both in experimental studies and in clinical trials, the aim of this study is to prepare and characterize a new liposomal delivery system that encapsulates simvastatin to improve its delivery into the brain.

MATERIALS AND METHODS

In order to select the optimal liposome lipid composition with the highest capacity to reach the brain, male Wistar rats were submitted to sham or transitory middle cerebral arterial occlusion (MCAOt) surgery and treated (intravenous [IV]) with fluorescent-labeled liposomes with different net surface charges. Ninety minutes after the administration of liposomes, the brain, blood, liver, lungs, spleen, and kidneys were evaluated ex vivo using the Xenogen IVIS(®) Spectrum imaging system to detect the load of fluorescent liposomes. In a second substudy, simvastatin was assessed upon reaching the brain, comparing free and encapsulated simvastatin (IV) administration. For this purpose, simvastatin levels in brain homogenates from sham or MCAOt rats at 2 hours or 4 hours after receiving the treatment were detected through ultra-high-protein liquid chromatography.

RESULTS

Whereas positively charged liposomes were not detected in brain or plasma 90 minutes after their administration, neutral and negatively charged liposomes were able to reach the brain and accumulate specifically in the infarcted area. Moreover, neutral liposomes exhibited higher bioavailability in plasma 4 hours after being administered. The detection of simvastatin by ultra-high-protein liquid chromatography confirmed its ability to cross the blood-brain barrier, when administered either as a free drug or encapsulated into liposomes.

CONCLUSION

This study confirms that liposome charge is critical to promote its accumulation in the brain infarct after MCAOt. Furthermore, simvastatin can be delivered after being encapsulated. Thus, simvastatin encapsulation might be a promising strategy to ensure that the drug reaches the brain, while increasing its bioavailability and reducing possible side effects.

Statins in Acute Ischemic Stroke: A Systematic Review

BACKGROUND AND PURPOSE

Statins have pleiotropic effects of potential neuroprotection. However, because of lack of large randomized clinical trials, current guidelines do not provide specific recommendations on statin initiation in acute ischemic stroke (AIS). The current study aims to systematically review the statin effect in AIS.

METHODS

From literature review, we identified articles exploring prestroke and immediate post-stroke statin effect on imaging surrogate markers, initial stroke severity, functional outcome, and short-term mortality in human AIS. We summarized descriptive overview. In addition, for subjects with available data from publications, we conducted meta-analysis to provide pooled estimates.

RESULTS

In total, we identified 70 relevant articles including 6 meta-analyses. Surrogate imaging marker studies suggested that statin might enhance collaterals and reperfusion. Our updated meta-analysis indicated that prestroke statin use was associated with milder initial stroke severity (odds ratio [OR] [95% confidence interval], 1.24 [1.05-1.48]; P=0.013), good functional outcome (1.50 [1.29-1.75]; P<0.001), and lower mortality (0.42 [0.21-0.82]; P=0.0108). In-hospital statin use was associated with good functional outcome (1.31 [1.12-1.53]; P=0.001), and lower mortality (0.41 [0.29-0.58]; P<0.001). In contrast, statin withdrawal was associated with poor functional outcome (1.83 [1.01-3.30]; P=0.045). In patients treated with thrombolysis, statin was associated with good functional outcome (1.44 [1.10-1.89]; P=0.001), despite an increased risk of symptomatic hemorrhagic transformation (1.63 [1.04-2.56]; P=0.035).

CONCLUSIONS

The current study findings support the use of statin in AIS. However, the findings were mostly driven by observational studies at risk of bias, and thereby large randomized clinical trials would provide confirmatory evidence.

Statin therapy does not affect the radiographic and clinical profile of patients with TIA and minor stroke

BACKGROUND AND PURPOSE

Acute statin therapy improves neurologic outcome and diminishes infarct growth in animal models of stroke. Clinical studies suggest that premorbid and early statin use is associated with improved outcome after major stroke. We studied the association between statin therapy and radiographic and clinical outcomes in patients with high-risk TIA and minor stroke.

MATERIALS AND METHODS

Patients with high-risk TIA and minor stroke (NIHSS ≤3) were prospectively enrolled within 24 hours of symptom onset. Patients were followed clinically for 3 months, and a subset had a repeat MR imaging at 90 days.

RESULTS

Of 418 patients, 23% were prescribed statins before their stroke. Statins were continued in 20% and initiated in 42%. Patients on prior statin therapy were older and more hypertensive, treated with aspirin, and more likely to have symptomatic carotid disease compared with those not on statin. Adjusting for these differences, prior statin treatment was not associated with DWI positivity (adjusted OR = 1.3; 95% CI, 0.77-2.1; P = .32) or smaller median baseline infarct volume, 1.1 mL (interquartile range = 4) versus 1 mL (interquartile range = 2.5; P = .56). Early or continued treatment with statins did not improve the risk of clinical deterioration (adjusted OR = 0.66; 95% CI, 0.27-1.6; P = .35) or poor functional outcome at 3 months (adjusted OR = 0.66; 95% CI, 0.35-1.24; P = .19).

CONCLUSIONS

Prestroke or early-stroke statin therapy was not associated with a reduction in the number of DWI lesions, infarct volume, or improved clinical or functional outcome at 3 months. The effect of acute statin treatment in patients with ischemic stroke/TIA remains unclear and needs further investigation.

Brain proteomics identifies potential simvastatin targets in acute phase of stroke in a rat embolic model

Finding an efficient neuroprotectant is of urgent need in the field of stroke research. The goal of this study was to test the effect of acute simvastatin administration after stroke in a rat embolic model and to explore its mechanism of action through brain proteomics. To that end, male Wistar rats were subjected to a Middle Cerebral Arteria Occlusion and simvastatin (20 mg/kg s.c) (n = 11) or vehicle (n = 9) were administered 15 min after. To evaluate the neuroprotective mechanisms of simvastatin, brain homogenates after 48 h were analyzed by two-dimensional fluorescence Difference in Gel Electrophoresis (DIGE) technology. We confirmed that simvastatin reduced the infarct volume and improved neurological impairment at 48 h after the stroke in this model. Considering our proteomics analysis, 66 spots, which revealed significant differences between groups, were analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry allowing the identification of 27 proteins. From these results, we suggest that simvastatin protective effect can be partly explained by the attenuation of the oxidative and stress response at blood-brain barrier level after cerebral ischemia. Interestingly, analyzing one of the proteins (HSP75) in plasma from stroke patients who had received simvastatin during the acute phase, we confirmed the results found in the pre-clinical model. Our aim was to study statins benefits when administered during the acute phase of stroke and to explore its mechanisms of action through brain proteomics assay. Using an embolic model, simvastatin-treated rats showed significant infarct volume reduction and neurological improvement compared to vehicle-treated group. Analyzing their homogenated brains by two-dimensional fluorescence Difference in Gel Electrophoresis (DIGE) technology, we concluded that the protective effect of simvastatin can be attributable to oxidative stress response attenuation and blood-brain barrier protection after cerebral ischemia.

Efficacy of lovastatin on learning and memory deficits caused by chronic intermittent hypoxia-hypercapnia: through regulation of NR2B-containing NMDA receptor-ERK pathway

BACKGROUND

Chronic intermittent hypoxia-hypercapnia (CIHH) exposure leads to learnning and memory deficits in rats. Overactivation of N-methyl-D-aspartate receptors(NMDARs) can lead to the death of neurons through a process termed excitotoxicity, which is involved in CIHH-induced cognitive deficits. Excessively activated NR2B (GluN2B)-containing NMDARs was reported as the main cause of excitotoxicity. The ERK1/2 (extracellular signal-regulated kinase 1/2) signaling cascade acts as a key component in NMDARs-dependent neuronal plasticity and survival. Ca2+/calmodulin-dependent protein kinase II (CaMKII), synapse-associated protein 102 (SAP102) and Ras GTPase-activating protein (SynGAP) have been shown to be involved in the regulation of NMDAR-ERK signalling cascade. Recent studies revealed statins (the HMG-CoA reductase inhibitor) have effect on the expression of NMDARs. The present study intends to explore the potential effect of lovastatin on CIHH-induced cognitive deficits and the NR2B-ERK signaling pathway.

METHODS AND FINDINGS

Eighty male Sprague Dawley rats were randomly divided into five groups. Except for those in the control group, the rats were exposed to chronic intermittent hypoxia-hypercapnia (CIHH) (9 ∼ 11%O2, 5.5 ∼ 6.5%CO2) for 4 weeks. After lovastatin administration, the rats performed better in the Morris water maze test. Electron microscopy showed alleviated hippocampal neuronal synaptic damage. Further observation suggested that either lovastatin or ifenprodil (a selective NR2B antagonist) administration similarly downregulated NR2B subunit expression leading to a suppression of CaMKII/SAP102/SynGAP signaling cascade, which in turn enhanced the phosphorylation of ERK1/2. The phosphorylated ERK1/2 induced signaling cascade involving cAMP-response element-binding protein (CREB) phosphorylation and brain-derived neurotrophic factor (BDNF) activation, which is responsible for neuroprotection.

CONCLUSIONS

These findings suggest that the ameliorative cognitive deficits caused by lovastatin are due to the downregulation of excessive NR2B expression accompanied by increased expression of ERK signaling cascade. The effect of NR2B in upregulating pERK1/2 maybe due, at least in part, to inactivation of CaMKII/SAP102/SynGAP signaling cascade.

HMG CoA reductase inhibitors (statins): use in stroke prevention and outcome after stroke

The use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) has been demonstrated to reduce the risk of primary and secondary ischemic stroke in patients with ischemic heart disease (relative risk reduction is 20-30%), confirmed by several prospective randomized placebo-controlled trials. At least one large prospective trial has also shown a similar benefit in patients without underlying ischemic heart disease. This is in contrast to an open-labeled trial conducted in the USA, which failed to demonstrate a significant benefit of statins in reducing stroke risk in hypertensive hyperlipidemic patients. It is less clear if treatment with statins before or after the onset of ischemic stroke also reduces its severity (improves outcome). Experimental animal studies where mice were pretreated with statins, demonstrated a reduced infarct size compared with untreated animals. Treatment with statins after stroke onset has also been demonstrated to enhance recovery without influencing infarct size (by increased angiogenesis, synaptogenesis and blood flow). A few clinical retrospective studies have demonstrated similar results. Prospective blinded placebo-controlled trials to test these findings are still lacking. This review discusses the various prospective trials in stroke prevention and available data on the effects of statins in improving outcome of established ischemic stroke. Alternate mechanisms of statins besides their lipid-lowering effect and relevance in reducing stroke risk and improving outcome are discussed. Finally, based on the present information, an evidence-based perspective about current and future use of statins in the short- and long-term management of ischemic stroke is presented.

Combining statins with tissue plasminogen activator treatment after experimental and human stroke: a safety study on hemorrhagic transformation

AIMS

Statins may afford neuroprotection against ischemic injury, but it remains controversial whether combined treatment with tissue plasminogen activator (tPA) after stroke increases the risk of hemorrhagic transformation (HT), the major tPA-related complication. We evaluated the safety of combining statin with tPA administration during the acute phase of both experimental and human stroke.

METHODS

The occurrence and severity of HT, infarct volume, and neurological outcome were evaluated in spontaneous hypertensive rats (SHR) subjected to embolic middle cerebral arterial occlusion (MCAO), which received vehicle or simvastatin (20 mg/kg), 15 min after ischemia and tPA (9 mg/kg) 3 h after ischemia. Additionally, HT rate was evaluated in stroke patients who were treated with tPA (0.9 mg/kg) within 3 h after symptom onset, considering whether or not were under statins treatment when the stroke occurred.

RESULTS

In the experimental study, no differences in HT rates and severity were found between treatment groups, neither regarding mortality, neurological deficit, infarct volume, or metalloproteinases (MMPs) brain content. In the clinical study, HT rates and hemorrhage type were similar in stroke patients who were or not under statins treatment.

CONCLUSION

This study consistently confirms that the use of statins does not increase HT rates and severity when is combined with tPA administration.

Stroke severity and outcomes for octogenarians receiving statins

Pre-exposure to 3-hydroxy-3-methylgutaryl-coenzyne A reductase inhibitors (statins) appears to improve outcomes in patients with acute ischemic stroke (AIS). Whether this extends to patients over 80 is not known. Patients ≥80 years of age with AIS were retrospectively reviewed from the stroke registry of a tertiary stroke center. Pre-admission statin use, demographics, vascular risk factors, and comorbid conditions were assessed. Primary outcomes were admission National Institutes of Health Stroke Scale (NIHSS) scores and in-hospital mortality/discharge to hospice, and secondary outcomes included subsequent intracerebral hemorrhage (ICH) and modified Barthel index (mBI) at 3 months. Multivariable logistic regression was used to evaluate the association between pre-admission statin use and outcomes among elderly patients. Among 804 patients ≥80, those taking statins prior to AIS admission were overall younger, were more likely to have hypertension, coronary artery disease, diabetes, hyperlipidemia, and were more likely to be on an antiplatelet, but less likely to receive treatment with IV tissue plasminogen activator (tPA). Patients on statin had lower stroke severity (NIHSS>16: 21.9% vs. 27.6%) and in-hospital mortality/discharge to hospice (22.8% vs. 27.6%), but neither was significant. There was no difference in ICH (1.2% vs. 1.9%), and patients on statins had a non-significant trend toward less disability on mBI (27.5% vs. 35.7%). Pre-admission statin use did not show a statistical difference in either outcome, but it did show a trend toward lower stroke severity and improved short-term outcomes. In addition, our study suggests that statins may be safe in elderly stroke patients and may not increase the risk of ICH.

The effect of statins on acute and long-term outcome after ischemic stroke in the elderly

BACKGROUND

Although treatment with statins has produced beneficial effects when used as secondary prevention, its primary protective role is still somewhat controversial. Moreover, few studies have evaluated the effect of statins in older patients with stroke.

OBJECTIVE

The aim was to investigate whether treatment with statins decreases stroke severity and/or improves survival and outcome after stroke in an older population.

METHODS

We investigated the association between previous statin use and stroke severity (National Institutes of Health Stroke Scale [NIHSS]), as well as the effect of poststroke statin treatment on 12-month functional outcome (modified Rankin Scale [mRS] score) in 799 patients (mean age, 78 years), with acute ischemic stroke. The effect of statin treatment on survival was examined using the Cox proportional hazard model, after adjusting for relevant covariates.

RESULTS

Statins did not decrease stroke severity and did not improve 30-day survival. However, both the 12-month survival (hazard ratio = 0.33; 95% CI, 0.20-to 0.54; P < 0.001) and the 12-month functional outcome (odds ratio = 2.09; 95% CI, 1.25-3.52; P = 0.005) were significantly better in the group treated with statins.

CONCLUSIONS

Significantly better survival and functional outcome were noted with poststroke statins at the end of the 12-month follow-up period. Statins seem to provide beneficial effects for the long-term functional outcome and survival in the elderly.

Statin treatment and functional outcome after ischemic stroke: case-control and meta-analysis

BACKGROUND AND PURPOSE

Multiple studies suggest that statin use before acute ischemic stroke is associated with improved functional outcome. However, available evidence is conflicting, and several published reports are limited by small sample sizes. We therefore investigated the effect of antecedent use of statins on stroke outcome by performing a meta-analysis of all results from published studies as well as our own unpublished data.

METHODS

We performed a systematic literature search and meta-analysis of studies investigating the association between prestroke statin use and clinical outcome and included additional data from 126 prestroke statin users and 767 nonusers enrolled at our institution. A total of 12 studies, comprising 2013 statin users and 9682 nonusers, was meta-analyzed using a random effects model. We also meta-analyzed results for individual Trial of ORG 10172 in Acute Stroke Treatment stroke subtypes to determine whether the effect of statin use differed across subtypes using the Breslow-Day test.

RESULTS

Meta-analysis of all available data identified an association between prestroke statin use and improved functional outcome (OR, 1.62; 95% CI, 1.39 to 1.88), but we uncovered evidence of publication bias. The effect of statin use on functional outcome was found to be larger for small vessel strokes compared with other subtypes (Breslow-Day P=0.008).

CONCLUSIONS

Antecedent use of statins is associated with improved outcome in patients with acute ischemic stroke. This association appears to be stronger in patients with small vessel stroke subtype. However, evidence of publication bias in the existing literature suggests these findings should be interpreted with caution.

Effect of in-hospital initiation of lipid-lowering therapy on six-month outcomes in patients with acute ischemic stroke or transient ischemic attack

Early lipid-lowering therapy (LLT) has demonstrated clinical benefits in patients with acute coronary syndrome; however, little is known about early LLT in patients with stroke. We evaluated the effect of in-hospital initiation of LLT on the clinical outcomes of patients with stroke. The Taiwan Stroke Registry prospectively collected data from patients with acute ischemic stroke or transient ischemic attack. By July 31, 2008, 16,704 adult patients without previous LLT had been admitted and survived to discharge. The study end point was the composite outcome of recurrent stroke, ischemic heart disease, and all-cause death. We examined the effect of LLT at discharge on the clinical outcomes of these patients. A propensity analysis was done to adjust for selection biases in the prescription of LLT. At discharge, 4,032 patients (24%) had received LLT. At 6 months, 206 patients (5.1%) in the LLT group and 964 patients (7.6%) in the non-LLT group had developed > or =1 component of the composite end point (p <0.0001). On multivariate Cox regression analysis, after adjustment for the potential confounders, LLT use at discharge was associated with a lower rate of the composite end point at 6 months (hazard ratio 0.78, 95% confidence interval 0.61 to 0.98, p = 0.013). In conclusion, our data have indicated that LLT has been underused in patients with stroke. In-hospital initiation of LLT was associated with a better clinical outcome in patients with ischemic stroke or transient ischemic attack.

Statin use before and after acute ischemic stroke onset improves neurological outcome

The devastating consequences of stroke, both in terms of morbidity and mortality, and the economic implications it has worldwide, coupled with a growing knowledge regarding its pathophysiology, has led to the development of novel therapeutic strategies in recent years that have had an enormous impact on clinical practice and the outcome of stroke patients. While thrombolysis is regarded as the most important of these developments, its relatively narrow therapeutic window and complexity of administration imply that only a minority of stroke patients can benefit from it. Among other strategies, in an attempt to overcome this limitation, research has focused on the development of neuroprotection aimed to salvage ischemic brain tissue by means complementary to reperfusion. Among these approaches, the use of statins stands out, which, by inhibiting the HMG CoA reductase, interfere with the formation of isoprenoid intermediates in the biosynthesis of cholesterol, and have been shown to have a positive impact in both the incidence and outcome of acute stroke. The main results of animal models, observational studies, clinical trials and opinion articles available in the medical literature covering the effect of statins on acute brain ischemia will be reviewed in order to provide in-depth information regarding their mode of action and current evidence regarding their potential benefits for ischemic stroke patients.

In vivo performance of simvastatin-loaded electrospun spiral-wound polycaprolactone scaffolds in reconstruction of cranial bone defects in the rat model

Reconstruction of large bone defects is still a major problem. Tissue-engineering approaches have become a focus in regeneration of bone. In particular, critical-sized defects do not ossify spontaneously. The use of electrospinning is attracting increasing attention in the preparation of tissue-engineering scaffolds. Recently, acellular scaffolds carrying bioactive agents have been used as scaffolds in "in situ" tissue engineering for soft and hard tissue repair. Poly(epsilon-caprolactone) (PCL) with two different molecular weights were synthesized, and the blends of these two were electrospun into nonwoven membranes composed of nanofibers/micropores. To stimulate bone formation, an active drug, "simvastatin" was loaded either after the membranes were formed or during electrospinning. The matrices were then spiral-wound to produce scaffolds with 3D-structures having both macro- and microchannels. Eight-millimeter diameter critical size cranial defects were created in rats. Scaffolds with or without simvastatin were then implanted into these defects. Samples from the implant sites were removed after 1, 3, and 6 months postimplantation. Bone regeneration and tissue response were followed by X-ray microcomputed tomography and histological analysis. These in vivo results exhibited osseous tissue integration within the implant and mineralized bone restoration of the calvarium. Both microCT and histological data clearly demonstrated that the more successful results were observed with the "simvastatin-containing PCL scaffolds," in which simvastatin was incorporated into the PCL scaffolds during electrospinning. For these samples, bone mineralization was quite significant when compared with the other groups.

Targeting eNOS and beyond: emerging heterogeneity of the role of endothelial Rho proteins in stroke protection

Currently available modalities for the treatment of acute ischemic stroke are aimed at preserving or augmenting cerebral blood flow. Experimental evidence suggests that statins, which show 25-30% reduction of stroke incidence in clinical trials, confer stroke protection by upregulation of eNOS and increasing cerebral blood flow. The upregulation of eNOS by statins is mediated by inhibition of small GTP-binding protein RhoA. Our recent study uncovered a unique role for a Rho-family member Rac1 in stroke protection. Rac1 in endothelium does not affect cerebral blood flow. Instead, inhibition of endothelial Rac1 leads to broad upregulation of the genes relevant to neurovascular protection. Intriguingly, inhibition of endothelial Rac1 enhances neuronal cell survival through endothelium-derived neurotrophic factors, including artemin. This review discusses the emerging therapeutic opportunities to target neurovascular signaling beyond the BBB, with special emphasis on the novel role of endothelial Rac1 in stroke protection.

High-dose lovastatin for acute ischemic stroke: results of the phase I dose escalation neuroprotection with statin therapy for acute recovery trial (NeuSTART)

BACKGROUND

Hydroxymethylglutaryl coenzyme A reductase inhibitors ('statins') reduce the neuronal injury in dose-dependent fashion in rodent stroke models. We sought to determine whether lovastatin at doses above those currently approved can be administered safely within 24 h after an acute ischemic stroke.

METHODS

We conducted a phase 1B dose-finding study using an adaptive design novel to stroke trials, the continual reassessment method, to find the highest tolerated dose of lovastatin. Planned doses were 1, 3, 6, 8 and 10 mg/kg/day for 3 days. The primary safety outcomes were myotoxicity and hepatotoxicity. The model was calibrated to select a dose causing 7-13% toxicity.

RESULTS

We enrolled 33 patients (16 men/17 women, age range 23-82 years). Three patients were treated at 1 mg/kg, 10 at 3 mg/kg, 12 at 6 mg/kg, and 8 at 8 mg/kg. Thirty of the 33 patients (90.9%) completed at least 11 of 12 doses. Two patients at the 6-mg/kg dose level experienced transient mild elevations in transaminases without clinical sequelae. After an initial dose reduction, the dose was re-escalated to 8 mg/kg, and no further patients reached safety outcomes. No clinical liver disease, myopathy, or creatine phosphokinase elevations occurred. The final model-based toxicity at 8 mg/kg was 13%; no patient was treated at 10 mg/kg.

CONCLUSIONS

Lovastatin at doses above those currently approved by the Food and Drug Administration is feasible for 3 days after an acute ischemic stroke and the maximum tolerated dose is estimated to be 8 mg/kg/day. Further randomized studies are warranted to confirm its safety and to demonstrate its efficacy in improving functional outcomes after stroke.

The Neuroprotection with Statin Therapy for Acute Recovery Trial (NeuSTART): an adaptive design phase I dose-escalation study of high-dose lovastatin in acute ischemic stroke

There is growing experimental and clinical evidence that by reducing downstream products of the mevalonate pathway other than cholesterol, HMG-CoA reductase inhibitors ('statins') have beneficial effects on endothelial function, coronary and cerebral blood flow, inflammation, and hemostasis. Statins have been shown in rodent models of acute ischemic stroke to reduce neuronal injury and infarct size in a dose-dependent fashion. The objective of this early phase trial will be to determine the maximal-tolerated dose of lovastatin for short-term acute stroke therapy. In this multicenter phase 1B dose-escalation and dose-finding study, 33 patients with acute ischemic stroke will be administered lovastatin in increasing doses from one to 10 mg/kg daily for 3 days beginning within 24 hours after symptom onset. The primary safety outcome will be occurrence of myotoxicity or hepatotoxicity, defined by clinical and laboratory criteria, and the study is designed to determine the highest dose of lovastatin that can be administered with <10% risk of myotoxicity or hepatotoxicity. The statistical design of the study utilizes an adaptive design, the Continual Reassessment Method, which is novel to stroke trials, to find the optimal dosage. The dose-toxicity model is calibrated such that the method will eventually select a dose that causes 7-13% dose-limiting toxicity (within 3% of target). A sample size of 33 will ensure that estimates of any binary variables will have a 95% confidence interval of width Collapse

Key Words

• stroke
• neuroprotection
• statins
• clinical trial

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MESH Headings

• Acute Disease
• Animals
• Brain Ischemia/drug therapy
• Brain Ischemia/prevention & control
• Dose-Response Relationship, Drug
• Drug Administration Schedule
• Drug Therapy, Combination
• Humans
• Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacokinetics
• Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use
• Hydroxymethylglutaryl-CoA Reductase Inhibitors/toxicity
• Lovastatin/pharmacokinetics
• Lovastatin/therapeutic use
• Lovastatin/toxicity
• Research Design
• Safety
• Stroke/drug therapy
• Stroke/prevention & control
• Time Factors

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Grants

• P50 NS049060 NINDS NIH HHS
• P50 NS049060-059004 NINDS NIH HHS
• P50 NS49060 NINDS NIH HHS

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Affiliation(s)

Mitchell S V Elkind Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
Ralph L Sacco
Robert B MacArthur
Daniel J Fink
Ellinor Peerschke
Howard Andrews
Greg Neils
Josh Stillman
Tania Corporan
Dana Leifer
Ken Cheung

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Statin Use is Independently Associated with Smaller Infarct Volume in Nonlacunar MCA Territory Stroke

BACKGROUND

Studies have shown an association between HMG-CoA reductase inhibitors (statins) and improved stroke outcomes, possibly secondary to neuroprotective properties.

OBJECTIVE

To assess whether patients taking statins prior to ischemic stroke have smaller infarcts on magnetic resonance imaging (MRI), adjusting for other relevant clinical factors.

DESIGN

We retrospectively reviewed the Cleveland Clinic Foundation (CCF) Neurology Inpatient Database from June 2002 through June 2004. Demographics, medications, stroke subtype, diffusion-weighted imaging (DWI) infarct volume, admission NIHSS, and hours to MRI were collected. Patients with a nonlacunar middle cerebral artery (MCA) territory infarct and MRI less than 48 hours from symptom onset were included (n= 143). A multivariable linear regression model was constructed to determine independent predictors of smaller infarct volume.

RESULTS

A total of 143 patients were studied, including 38 patients taking statins at the time of their stroke. In univariate analysis, patients using statins were significantly more likely to have a history of hyperlipidemia, atrial fibrillation, and coronary artery disease and to be using coumadin, antiplatelet drugs, and angiotensin-converting enzyme inhibitors. Patients on statins had a tendency toward smaller infarcts in univariate analysis (median 25.4 cm(3) vs. 15.5 cm(3), P= 0.054). In multivariable linear regression analysis statin use, patient age, and TIA within the prior 4 weeks were independently associated with smaller DWI volumes; vessel occlusion on vascular imaging, and cardioembolic stroke subtype with larger infarct size.

CONCLUSIONS

Statin use prior to the onset of nonlacunar MCA infarction was associated with a smaller infarct volume independent of other factors. Further studies utilizing both clinical and radiologic outcomes will be required to confirm these findings.

Treatment with statins in the acute phase of ischemic stroke

Although statins are being used for the secondary prevention of ischemic stroke, recent experimental data have shown new pleiotropic effects of these drugs independent of their lipid-lowering properties that might be responsible for their role in neuroprotection. In fact, statins have been successfully tested in animal models of acute cerebral ischemia. In humans, the possibility that statins could be used for the treatment of acute ischemic stroke has not yet been addressed, however, a pilot trial and observational studies testing this approach showed promising results for a disease in which tissue plasminogen activator is the only available treatment for a reduced number of patients. The aim of this review is to answer the basic question of whether treatment with statins initiated in the acute phase of ischemic stroke is feasible and if it can improve neurologic outcome. The possible benefits of this scenario will be discussed.

Advances in stroke neuroprotection: hyperoxia and beyond

Refinements in patient selection, improved methods of drug delivery, use of more clinically relevant animal stroke models, and the use of combination therapies that target the entire neurovascular unit make stroke neuroprotection an achievable goal. This article provides an overview of the major mechanisms of neuronal injury and the status of neuroprotective drug trials and reviews emerging strategies for treatment of acute ischemic stroke. Advances in the fields of stem cell transplantation, stroke recovery, molecular neuroimaging, genomics, and proteomics will provide new therapeutic avenues in the near future. These and other developments over the past decade raise expectations that successful stroke neuroprotection is imminent.

Statins: potential new indications in inflammatory conditions

Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are potent cholesterol-lowering drugs. In addition to their cholesterol-lowering properties, statins exert a number of so-called 'pleiotropic', vasculoprotective actions that include improvement of endothelial function, increased nitric oxide (NO) bioavailability, antioxidant properties, stabilisation of atherosclerotic plaques, regulation of progenitor cells, inhibition of inflammatory responses and immunomodulatory actions. Pleiotropic actions of statins may have potential clinical impact in vascular disease beyond cholesterol lowering. The ongoing Justification for the Use of statins in Primary prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER), for example, tests the effects of statins in the primary prevention of cardiovascular disease among patients with low levels of low-density lipoprotein cholesterol (LDL-C) and elevated high-sensitivity C-reactive protein (hs-CRP). Additionally, previous studies have shown that although cholesterol is not an established stroke risk factor, statin therapy is associated with a reduction in the incidence of strokes. It is known that sudden withdrawal of statin treatment may acutely impair vascular function and increase morbidity and mortality in patients with vascular disease. Furthermore, the anti-inflammatory effects of statins may have clinical impact in a number of non-vascular conditions including multiple sclerosis and rheumatoid arthritis.

Simvastatin reduces caspase-3 activation and inflammatory markers induced by hypoxia–ischemia in the newborn rat

The present study was undertaken to evaluate whether in a neonatal model of stroke a prophylactic neuroprotective treatment with simvastatin modulates hypoxia-ischemia-induced inflammatory and apoptotic signaling. Procaspase-3 and cleaved caspase-3 expression showed a peak at 24 h and returned to control values after 5 days. Caspase-3 activity followed the same pattern of caspase-3 proteolytic cleavage. In simvastatin-treated ischemic animals, the expression of these proteins and caspase-3 activity were significantly lower when compared to that of ischemic animals. alpha-Spectrin and protein kinase C-alpha (PKCalpha) cleavages were not affected by the treatment. Poly (ADP-ribose) polymerase fragmentation, caspase-1 activation, and IL-1beta and ICAM-1 mRNA expression were increased by hypoxia-ischemia and significantly reduced in simvastatin-treated animals. The results indicate that simvastatin-induced attenuation of hypoxia-ischemia brain injury in the newborn rat occurs through reduction of the inflammatory response, caspase-3 activation, and apoptotic cell death.

Lipids and stroke: the opportunity of lipid-lowering treatment

Dyslipemia is a clear risk factor (RF) for ischemic heart disease and peripheral artery disease, but its relation with ischemic stroke (IS) is not so clear. HMG-CoA reductase inhibitor drugs or statins (simvastatin, atorvastatin, pravastatin) reduce the relative risk of IS by between 18 and 51% in patients with IHD, in patients with high vascular disease risk and in hypertensive patients with other RFs, acute coronary syndrome, and type 2 diabetes mellitus. According to the guidelines for use, statins are indicated in the majority of patients with IS since the risk is equivalent to that of IHD or high vascular disease risk. In view of the existing clinical evidence of benefit, it would not seem unreasonable to proceed with treatment of patients using statins while awaiting specific studies justifying their use. The non-lipid-lowering mechanisms of the statins and results of studies, such as the Heart Protection Study, provide evidence for widening the indications of statins beyond the prevention of dyslipemia, as a new therapeutic approach in the prevention of IS in patients with plasma levels of total cholesterol or low density lipoproteins currently considered within the normal distribution. The neuroprotective role, which these drugs may play in the acute phase of cerebral ischemia, remains to be clarified, but very recent evidence suggests that such patients may also benefit.

Statins and stroke

Inhibitors of HMG-CoA reductase (statins) are potent cholesterol-lowering drugs. Large clinical trials have shown that statins reduce the incidence of cerebrovascular events, which might be surprising because cholesterol is not an established risk factor for stroke. In addition to their cholesterol-lowering properties, statins exert a number of pleiotropic, vasculoprotective actions that include improvement of endothelial function, increased nitric oxide (NO) bioavailability, antioxidant properties, inhibition of inflammatory responses, immunomodulatory actions, regulation of progenitor cells, and stabilization of atherosclerotic plaques. In fact, statins augment cerebral blood flow and confer significant protection in animal models of stroke partly via mechanisms related to the upregulation of endothelial nitric oxide synthase. Retrospective clinical evidence suggests that long-term statin administration may not only reduce stroke risk but also improve outcome. Early secondary prevention trials are underway to test the hypothesis that statin treatment initiated immediately after an event improves short-term outcome. Lastly, recent evidence suggests that sudden discontinuation of statin treatment leads to a rebound effect with downregulation of NO production. Withdrawal of statin treatment may impair vascular function and increase morbidity and mortality in patients with vascular disease.

Statin administration prior to ischaemic stroke onset and survival: exploratory evidence from matched treatment-control study

In addition to their lipid-lowering effects, it has been speculated that statins may also have beneficial effects on cerebral circulation and brain parenchyma during ischaemic stroke and reperfusion. We hypothesized that patients who had taken statins prior to stroke onset may have a better survival rate at 1 month and during the follow-up period. We retrospectively studied consecutive ischaemic stroke patients admitted to an acute stroke unit and at least a month's follow-up. From these, we included those patients who, at admission, had reported the use of a statin prior to the stroke onset in the statin group (n = 205). Each patient in the statin group was matched with two patients who reported no statin use (n = 410). Using logistic regression and Cox proportional hazards models, we adjusted for variables that significantly differed between treatment groups or that independently predicted mortality. After adjusting for those variables, statin use was associated with reduced mortality at 1 month [odds ratio 0.24; 95% confidence interval (CI) 0.09-0.67] and during the follow-up period (hazard ratio 0.57; 95% CI 0.35-0.93). The use of statins prior to stroke onset is associated with improved stroke survival within this cohort study with matched controls.

Statine zur Behandlung von Erkrankungen des zentralen Nervensystems

3-Hydroxy-3-methyglutaryl coenzyme A (HMG-CoA) reductase inhibitors, "statins," are widely used oral cholesterol-lowering drugs. Statins competitively inhibit HMG-CoA reductase, the enzyme that catalyzes conversion of HMG-CoA to L-mevalonate, a key intermediate in cholesterol synthesis. Certain metabolites of L-mevalonate are also involved in posttranslational modifications of specific proteins with cell proliferation and differentiation properties. Thus, statins have important biologic effects beyond their cholesterol-reducing properties. Here we discuss recent experimental and clinical data that may support a potential role for statins in the treatment of three central nervous system (CNS) neurological diseases: Multiple sclerosis (MS), Alzheimer's disease (AD), and ischemic stroke. Despite their considerable pathogenic differences, in animal models of these disorders statins have shown beneficial effects. In both stroke and AD cohort studies suggest a beneficial treatment effect in humans; in MS, results from small open-label studies look encouraging. Multicenter, randomized, placebo-controlled clinical trials are in the planning or recruiting stage to evaluate the therapeutic effects of statins in all three disorders.

Effect of Prior Statin Use on Functional Outcome and Delayed Vasospasm after Acute Aneurysmal Subarachnoid Hemorrhage: A Matched Controlled Cohort Study

OBJECTIVE

Hydroxymethylglutaryl coenzyme A reductase inhibitors (statins), which exhibit beneficial cerebrovascular effects by modulating inflammation and nitric oxide production, have not been evaluated in acute aneurysmal subarachnoid hemorrhage (SAH) patients. The effect of prior statin use on 14-day functional outcome and on prevention of vasospasm-induced delayed cerebral ischemia (DCI) or stroke during hospitalization was analyzed.

METHODS

We conducted a 1:2 matched (age, admission Hunt and Hess grade, vascular disease/risk history) cohort study of 20 SAH patients on statins and 40 SAH controls. The primary outcome was functional outcome at 14 days (Modified Lawton Physical Self-Maintenance Scale and Barthel Index scale scores). Secondary outcomes were 14-day mortality, Modified Rankin Scale score, DCI, DCI supported by angiography/transcranial Doppler [TCD], cerebral infarctions of any type, and TCD highest mean velocity elevation.

RESULTS

Statin users demonstrated a significant protective effect on 14-day Barthel Index scale and Modified Lawton Physical Self-Maintenance Scale scores (77 +/- 10 versus 39 +/- 8, P = 0.003; 12 +/- 7 versus 19 +/- 9, P = 0.03, respectively). Moreover, statin users demonstrated a significantly lower incidence of DCI and DCI supported by angiography/TCD (10% versus 43%, P = 0.02; 5% versus 35%, P = 0.01, respectively), cerebral infarctions of any type (25% versus 63%, P = 0.01), and baseline-to-final TCD highest mean velocity change of 50 cm/s or greater (18% versus 51%, P = 0.03).

CONCLUSION

SAH statin users demonstrated significant improvement in 14-day functional outcome, a significantly lower incidence of DCI and cerebral infarctions of any type, as well as prevention of TCD highest mean velocity elevation. However, we did not find a significant statin impact on mortality or global outcome (Modified Rankin Scale) in this small sample. This study provides clinical evidence for the potential therapeutic benefit of statins after acute SAH.

Changes in flow-mediated dilatation, cytokines and carotid arterial stenosis during aggressive atorvastatin treatment in normocholesterolemic patients

BACKGROUND

Aggressive statin therapy to reduce low-density lipoprotein (LDL) cholesterol in patients with normal LDL-cholesterol levels reduces the incidence of future cardiovascular events and enhances atherosclerotic regression in the common carotid artery. We tried to quantify changes in flow-mediated dilatation (FMD), inflammatory cytokines, and the severity of carotid arterial stenosis, after aggressive statin administration to patients with normal LDL-cholesterol levels, and stroke or transient ischemic attack ipsilateral to carotid arterial stenosis.

METHODS

Twenty patients with at least a 50% reduction in the diameter of the carotid artery were studied. Atorvastatin 10 mg daily was prescribed for 4 months. Serial changes in the severity of carotid arterial stenosis, and brachial-artery FMD were evaluated by high-resolution ultrasound. Tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), vascular cell adhesion molecule (VCAM), intracellular adhesion molecule (ICAM), soluble endothelin-1 (ET-1), and high-sensitivity C-reactive protein (hs-CRP), were measured before, and after 2 and 4 months of, atorvastatin treatment.

RESULTS

Atorvastatin significantly decreased plasma levels of total cholesterol and LDL-cholesterol after 1, 2 and 4 months of treatment (p < 0.01). FMD showed significant improvement after only 4 months (10.0% vs 6.8% at baseline; p = 0.019). The overall severity of carotid arterial lesions was not significantly reduced by atorvastatin. Changes in TNF-alpha, IL-1beta, IL-6 and ET-1 showed trends towards a progressive decline after atorvastatin, but none of the cytokines was reduced significantly. FMD did not correlate with the severity of carotid arterial stenosis, lipid profile, or cytokine levels.

CONCLUSION

Atorvastatin effectively reduced plasma concentrations of total cholesterol and LDL-cholesterol, and had beneficial effects on endothelial function, in Chinese patients with carotid arterial stenosis and normal LDL-cholesterol levels.

Effect of pretreatment with statins on the severity of acute ischemic cerebrovascular events

OBJECTIVE

Treatment with statins reduces the risk of ischemic stroke among patients at increased risk for vascular disease. Recent experimental data suggest neuroprotective properties of statins in acute cerebral ischemia. We investigated whether a premedication with statins is associated with a better outcome in patients with acute ischemic cerebrovascular events.

METHODS

Within a cross-sectional study, nested in a cohort we identified 1691 patients with a recent ischemic stroke or transient ischemic attack. Clinical severity of the vascular event was evaluated by the modified Rankin Scale (mRS) after 1 week. By means of multivariate logistic regression modeling, we determined the influence of prior statin use on stroke severity with adjustment for potential confounding factors.

RESULTS

Severe stroke, defined as a modified Rankin Scale of 5 or 6 (n=231; 14%), was less frequent in patients receiving statin treatment before the event (6% vs. 14%, OR=0.37; 95% CI 0.19 to 0.74; p=0.004). This association remained significant after adjustment for confounding factors. We found a significant interaction between the presence of diabetes and the effect of pretreatment with statins on stroke outcome. Of the patients with diabetes, none of those on statin treatment but 16% of those without a statin had a bad outcome. After exclusion of the group of diabetic patients with prior statin medication, the protective effect was reduced and not statistically significant anymore.

CONCLUSIONS

Pretreatment with statins seems to be associated with reduced clinical severity in patients with acute ischemic cerebrovascular events, particularly in patients with diabetes.

Targeting eNOS for stroke protection

Nitric oxide (NO) generated by endothelial NO synthase (eNOS) plays a crucial role in vascular function and homeostasis. NO possesses vasodilatory, anti-inflammatory, antithrombotic and antiproliferative properties. Augmentation of NO production increases cerebral blood flow, which can lead to neuroprotection during brain ischaemia. Several modalities that upregulate eNOS expression and/or activity have recently been identified, including HMG-CoA reductase inhibitors (statins), steroid hormones, nutrients and physical activity. They all increase NO bioavailability, leading to enhanced cerebral blood flow and protection from ischaemic stroke. Thus, therapeutic modalities that target eNOS not only serve as preventive measures to reduce stroke incidence but also could represent novel treatment strategies for reducing brain injury during cerebral ischaemia.

Rising statin use and effect on ischemic stroke outcome

BACKGROUND

Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) have neuroprotective effects in experimental stroke models and are commonly prescribed in clinical practice. The aim of this study was to determine if patients taking statins before hospital admission for stroke had an improved clinical outcome.

METHODS

This was an observational study of 436 patients admitted to the National Institutes of Health Suburban Hospital Stroke Program between July 2000 and December 2002. Self-reported risk factors for stroke were obtained on admission. Stroke severity was determined by the admission National Institutes of Health Stroke Scale score. Good outcome was defined as a Rankin score < 2 at discharge. Statistical analyses used univariate and multivariate logistic regression models.

RESULTS

There were 436 patients with a final diagnosis of ischemic stroke; statin data were available for 433 of them. A total of 95/433 (22%) of patients were taking a statin when they were admitted, rising from 16% in 2000 to 26% in 2002. Fifty-one percent of patients taking statins had a good outcome compared to 38% of patients not taking statins (p = 0.03). After adjustment for confounding factors, statin pretreatment was associated with a 2.9 odds (95% CI: 1.2-6.7) of a good outcome at the time of hospital discharge.

CONCLUSIONS

The proportion of patients taking statins when they are admitted with stroke is rising rapidly. Statin pretreatment was significantly associated with an improved functional outcome at discharge. This finding could support the early initiation of statin therapy after stroke.

[Antilipemics: from prevention to protection]

Statins and fibrates have been demonstrated to prevent both cardiovascular events and stroke. While this preventive effect was initially thought to be related to their lipid-lowering effects, in particular hypocholesterolaemic effect, analysis of primary and secondary prevention trials suggest that these preventive effects could be partly independent of their effects on lipid disorders. The pleiotropic effects, such as vascular, anti-inflammatory or anti-oxidants effects, were described for both the statins and fibrates. In addition to the preventive effects, these pleiotropic effects could partially explain the decrease in myocardial or cerebral ischemia consequences in experimental models. These cellular protective effects may have a therapeutic interest to decrease severity of stroke or coronary acute syndrome. They could also explain the drugs' lipid-lowering preventive effects independent of the treatment of lipid disorders. Beyond vascular pathologies, the pleiotropic effects of lipid-lowering drugs could explain their potentially beneficial effect in different diseases, such as dementia or cancer.

Matrix metalloproteinases and atherosclerotic plaque instability

BACKGROUND

There is growing interest in the role of matrix metalloproteinases in atherosclerosis. Excessive tissue remodelling and increased matrix metalloproteinase activity have been demonstrated during atherosclerotic plaque disruption, a frequent predeterminant of ischaemic cardiac events and stroke. These enzymes represent a potential target for therapeutic intervention to modify vascular pathology.

METHODS

The core of this review is derived from a Medline database literature search.

RESULTS

There is convincing evidence of increased matrix metalloproteinase activity during acute plaque disruption. Evidence for an imbalance promoting increased matrix degradation is less well documented. However, studies of matrix metalloproteinase inhibition in models of vascular disease suggest a potential therapeutic benefit.

CONCLUSION

In vivo studies of matrix metalloproteinase inhibition are required to study the potential for reversal or deceleration of the excessive tissue remodelling that accompanies acute plaque disruption.

The role of matrix metalloproteinases in vascular disease

There is growing interest in the role of matrix metalloproteinases in vascular diseases. These conditions are often characterized by excessive tissue remodelling, and increased matrix metalloproteinase activity has been demonstrated in aneurysms, intimal hyperplasia and atherosclerotic plaque disruption. These enzymes represent a potential target for therapeutic intervention to modify vascular pathology. The core of this review is derived from a MEDLINE database literature search. The review found that there is convincing evidence of increased matrix metalloproteinase activity in a spectrum of vascular disease. Evidence for an imbalance promoting increased matrix degradation is less well documented. However, studies of matrix metalloproteinase inhibition in vascular disease models suggest potential therapeutic benefit. In conclusion, in vivo studies of matrix metalloproteinase inhibition are required to further study the potential for reversal or deceleration of the excessive tissue remodelling that accompanies vascular disorders.