Guidelines for the Neurocritical Care Management of Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The neurointensive care management of patients with aneurysmal subarachnoid hemorrhage (aSAH) is one of the most critical components contributing to short-term and long-term patient outcomes. Previous recommendations for the medical management of aSAH comprehensively summarized the evidence based on consensus conference held in 2011. In this report, we provide updated recommendations based on appraisal of the literature using the Grading of Recommendations Assessment, Development, and Evaluation methodology.

METHODS

The Population/Intervention/Comparator/Outcome (PICO) questions relevant to the medical management of aSAH were prioritized by consensus from the panel members. The panel used a custom-designed survey instrument to prioritize clinically relevant outcomes specific to each PICO question. To be included, the study design qualifying criteria were as follows: prospective randomized controlled trials (RCTs), prospective or retrospective observational studies, case-control studies, case series with a sample larger than 20 patients, meta-analyses, restricted to human study participants. Panel members first screened titles and abstracts, and subsequently full text review of selected reports. Data were abstracted in duplicate from reports meeting inclusion criteria. Panelists used the Grading of Recommendations Assessment, Development, and Evaluation Risk of Bias tool for assessment of RCTs and the "Risk of Bias In Nonrandomized Studies - of Interventions" tool for assessment of observational studies. The summary of the evidence for each PICO was presented to the full panel, and then the panel voted on the recommendations.

RESULTS

The initial search retrieved 15,107 unique publications, and 74 were included for data abstraction. Several RCTs were conducted to test pharmacological interventions, and we found that the quality of evidence for nonpharmacological questions was consistently poor. Five PICO questions were supported by strong recommendations, one PICO question was supported by conditional recommendations, and six PICO questions did not have sufficient evidence to provide a recommendation.

CONCLUSIONS

These guidelines provide recommendations for or against interventions proven to be effective, ineffective, or harmful in the medical management of patients with aSAH based on a rigorous review of the available literature. They also serve to highlight gaps in knowledge that should guide future research priorities. Despite improvements in the outcomes of patients with aSAH over time, many important clinical questions remain unanswered.

A Systematic Review and Meta-Analysis of Statins in Animal Models of Intracerebral Hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is a severe form of stroke with limited treatment options. Statins have shown promise as a therapy for ICH in animal and human studies. We systematically reviewed and assessed the quality of preclinical studies exploring statin-use after ICH to guide clinical trial decision-making and design.

METHODS

We identified preclinical trials assessing the efficacy of statins in ICH via a systematic review of the literature according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. In total, 16 studies were identified that described statin use in an animal model of ICH and assessed histological outcomes, behavioral scores, or both. Design characteristics were analyzed using Stroke Therapy Academic Industry Roundtable (STAIR) criteria modified for ICH. Meta-analysis was performed using a random effects model.

RESULTS

Behavioral outcomes were assessed in 12 of the studies with 100% (n = 12) reporting that statins significantly improved ICH recovery. Histologic hematoma volume and brain water content outcomes were analyzed in 10 of the studies, with 50% (n = 5) reporting significant improvement. The ratio of means between experimental and control cases for modified Neurological Severity Score was 0.63 (95% confidence interval 0.49-0.82). The ratio of means between experimental and control cases for hemorrhagic volume was 0.85 (95% confidence interval 0.70-1.03). There was heterogeneity between studies (P < 0.0001) but no evidence of publication bias (P = 0.89, P = 0.59, respectively).

CONCLUSIONS

Behavioral outcomes in ICH were found to consistently improve with administration of statins in preclinical studies suggesting that statin therapy may be suitable for randomized clinical trials in humans. In addition, the STAIR criteria can be modified to effectively evaluate preclinical studies in ICH.

Antiplatelet therapy does not increase mortality of surgical treatment for spontaneous intracerebral haemorrhage

OBJECTIVES

This study aimed to find the effect of antiplatelet therapy on hematoma volume, rehaemorrhage rate and prognosis of intracerebral hemorrhage patients after surgery.

PATIENTS AND METHODS

101 surgically treated intracerebral hemorrhage subjects were included and analyzed retrospectively. Prior antiplatelet therapy was ascertained from the clinical history, and the patients included were divided into two groups: antiplatelet therapy and no antiplatelet therapy group. The in-hospital and follow-up outcomes were assessed with the Modified Rankin Scale and were compared between the 2 groups after 1:2 propensity score matching.

RESULTS

Before the diagnosis of intracerebral hemorrhage, 21.8 % patients were not on antiplatelet therapy. Antiplatelet therapy group had larger hematoma volume (99.32 mL versus 73.75 mL) with no significant difference (P = 0.308). After propensity score matching, 42 patients were obtained. 4(9.5 %) had rehaemorrhage after surgery, and antiplatelet therapy was not related to higher rehaemorrhage rate (P = 0.628). After follow-up, the overall mortality was 29.3 %, and 22 patients (53.7 %) ended up with severe morbidity. In the multivariate regression, plasma fibrinogen was an independent predictor of both in-hospital and follow-up overall mortality (P = 0.044; P = 0.016), and prior antiplatelet therapy was found to predict better follow-up functional outcome independently (P = 0.032).

CONCLUSION

Among surgically treated intracerebral hemorrhage patients, prior antiplatelet therapy did not increase hematoma volume, rehaemorrhage rate and mortality, and was related to lower follow-up severe morbidity independently.

Dose-Dependent Effects of Statins for Patients with Aneurysmal Subarachnoid Hemorrhage: Meta-Regression Analysis

OBJECTIVE

The study uses meta-regression analysis to quantify the dose-dependent effects of statin pharmacotherapy on vasospasm, delayed ischemic neurologic deficits (DIND), and mortality in aneurysmal subarachnoid hemorrhage.

METHODS

Prospective, retrospective observational studies, and randomized controlled trials (RCTs) were retrieved by a systematic database search. Summary estimates were expressed as absolute risk (AR) for a given statin dose or control (placebo). Meta-regression using inverse variance weighting and robust variance estimation was performed to assess the effect of statin dose on transformed AR in a random effects model. Dose-dependence of predicted AR with 95% confidence interval (CI) was recovered by using Miller's Freeman-Tukey inverse.

RESULTS

The database search and study selection criteria yielded 18 studies (2594 patients) for analysis. These included 12 RCTs, 4 retrospective observational studies, and 2 prospective observational studies. Twelve studies investigated simvastatin, whereas the remaining studies investigated atorvastatin, pravastatin, or pitavastatin, with simvastatin-equivalent doses ranging from 20 to 80 mg. Meta-regression revealed dose-dependent reductions in Freeman-Tukey-transformed AR of vasospasm (slope coefficient -0.00404, 95% CI -0.00720 to -0.00087; P = 0.0321), DIND (slope coefficient -0.00316, 95% CI -0.00586 to -0.00047; P = 0.0392), and mortality (slope coefficient -0.00345, 95% CI -0.00623 to -0.00067; P = 0.0352).

CONCLUSIONS

The present meta-regression provides weak evidence for dose-dependent reductions in vasospasm, DIND and mortality associated with acute statin use after aneurysmal subarachnoid hemorrhage. However, the analysis was limited by substantial heterogeneity among individual studies. Greater dosing strategies are a potential consideration for future RCTs.

Dose-related effect of statins in patients with endovascular coiling or microsurgical clipping for aneurysmal subarachnoid hemorrhage: updated study-level meta-analysis

PURPOSE

We aimed to quantitatively assess the effects of short-term statin use on delayed ischemic neurologic deficits (DINDs) and clinical outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH) through a meta-analysis of the available evidence.

METHODS

We searched the electronic databases up to April 8, 2016 to retrieve relevant studies comparing the outcomes between immediate statin-treated in statin-naïve patients and untreated patients following aneurysmal SAH. Meta-analysis was performed using Review Manager 5.3.

RESULTS

Eight randomized controlled clinical trials (RCTs) and 5 observational studies involving 2148 patients met the eligibility criteria. In the RCTs, statins were found to significantly reduce the occurrence of DINDs (relative risk (RR), 0.76; 95% confidence interval (CI), 0.61-0.94; P = 0.01), but did not significantly reduce poor functional outcomes (RR, 1.01; 95% CI, 0.87-1.16; P = 0.93) or mortality (RR, 0.80; 95% CI, 0.58-1.11; P = 0.18). In observational studies, statin use was not associated with any reduction in DINDs, poor outcome, or mortality. Meta-analysis of RCTs indicated a significant reduction in DINDs and mortality in patients with high-dose statin use (RR, 0.63; 95% CI, 0.42-0.95; P = 0.03; I ² = 0%; and RR, 0.36; 95% CI, 0.15-0.86; P = 0.02; I ² = 0%, respectively).

CONCLUSION

The present meta-analysis suggests that statin use may prevent DINDs in patients with aneurysmal SAH. Based on our findings, the role of statins in improving neurological outcome was limited. However, the risk of DINDs and mortality decreased with higher statin doses in a dose-dependent manner. Hence, further well-designed RCTs with modified protocols in specific patients are required.

Effects of simvastatin and taurine on delayed cerebral vasospasm following subarachnoid hemorrhage in rabbits

The aim of the current study was to observe the effects of simvastatin and taurine on delayed cerebral vasospasm (DCVS) following experimental subarachnoid hemorrhage (SAH) in rabbits. A total of 48 New Zealand white rabbits were allocated at random into four groups (control, SAH, SAH + simvastatin and SAH + taurine groups; n=12 each). The rabbit model of DCVS was established using a double hemorrhage method, which involved injecting autologous arterial blood into the cisterna magna in the SAH groups. The SAH + simvastatin group was administered oral simvastatin (5 mg/kg) daily between days 0-6. The SAH + taurine group was administered oral taurine (50 mg/kg) daily between days 0-6. Starch (50 mg/kg) was administered orally to the animals in the other two groups (control and SAH groups). The control group were not subjected to any other injections or treatment. The internal diameter and internal diameter/wall thickness of the basilar artery (BA) were measured. The expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were determined using immunohistochemical and quantitative polymerase chain reaction methods following the sacrifice of all animals on day 7. The activity of nuclear factor (NF)-κB in the BA was also measured using an electrophoretic mobility shift assay. The BA walls in the SAH + simvastatin and SAH + taurine groups exhibited reduced narrowing and corrugation of the tunica elastica interna compared with the SAH group. At the protein and cDNA levels, it was found that cerebral vasospasm of the BA in the SAH + simvastatin and SAH + taurine groups was alleviated, as indicated by the reduced expression of TNF-α, IL-1β, IL-6 and NF-κB compared with the SAH group (P<0.05). In conclusion, simvastatin and taurine reduced DCVS following SAH in rabbits, which suggests that these compounds may exert anti-inflammatory effects.

Current controversies in the prediction, diagnosis, and management of cerebral vasospasm: where do we stand?

Aneurysmal subarachnoid hemorrhage occurs in approximately 30,000 persons in the United States each year. Around 30 percent of patients with aneurysmal subarachnoid hemorrhage suffer from cerebral ischemia and infarction due to cerebral vasospasm, a leading cause of treatable death and disability following aneurysmal subarachnoid hemorrhage. Methods used to predict, diagnose, and manage vasospasm are the topic of recent active research. This paper utilizes a comprehensive review of the recent literature to address controversies surrounding these topics. Evidence regarding the effect of age, smoking, and cocaine use on the incidence and outcome of vasospasm is reviewed. The abilities of different computed tomography grading schemes to predict vasospasm in the aftermath of subarachnoid hemorrhage are presented. Additionally, the utility of different diagnostic methods for the detection and visualization of vasospasm, including transcranial Doppler ultrasonography, CT angiography, digital subtraction angiography, and CT perfusion imaging is discussed. Finally, the recent literature regarding interventions for the prophylaxis and treatment of vasospasm, including hyperdynamic therapy, albumin, calcium channel agonists, statins, magnesium sulfate, and endothelin antagonists is summarized. Recent studies regarding each topic were reviewed for consensus recommendations from the literature, which were then presented.

Cholesterol-reducing agents for aneurysmal subarachnoid haemorrhage

BACKGROUND

Cerebral vasospasm and related delayed ischaemic deficits (DIDs) occur in about 17% to 40% of patients with aneurysmal subarachnoid haemorrhage (SAH) and lead to a poor outcome. Cholesterol-reducing agents might improve unfavourable outcomes.

OBJECTIVES

To assess the effects of cholesterol-reducing agents for improving outcomes in patients with aneurysmal SAH.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (May 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 5), MEDLINE (1948 to May 2012) and EMBASE (1980 to May 2012). We also searched three Chinese databases: SinoMed, CNKI and VIP (May 2012). In an effort to identify further published, ongoing and unpublished trials we searched relevant clinical trials and research registers (May 2012), contacted pharmaceutical companies and investigators known to be involved in previous trials and screened the reference lists of all relevant articles identified.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared cholesterol-reducing agents with control or placebo treatment in participants with aneurysmal SAH.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, reviewed the relevant trials and extracted data. We did not perform meta-analysis as we only included one RCT in the review.

MAIN RESULTS

We included one study in which 39 patients received either simvastatin (80 mg daily; n = 19) or placebo (n = 20) for 14 days. The incidence of DIDs (secondary outcome) was 26% (5/19) in the simvastatin group versus 60% (12/20) in the placebo group (risk ratio (RR) 0.44, 95% confidence interval (CI) 0.19 to 1.01, P = 0.05). This means that, in this study, simvastatin had no effect on DIDs. Two patients in the simvastatin group and one patient in the placebo group had elevated levels of aspartate transaminase or alanine transaminase. One patient in the simvastatin group had a raised creatine phosphokinase. There were no results from this trial for the primary outcome of death or dependency at six months.

AUTHORS' CONCLUSIONS

We cannot draw any conclusions about the effectiveness and safety of lowering cholesterol in aneurysmal SAH because of insufficient reliable evidence from only one small trial. More RCTs are needed.

Statins in the critically ill

The use or misuse of statins in critically ill patients recently attracted the attention of intensive care clinicians. Indeed, statins are probably the most common chronic treatment before critical illness and some recent experimental and clinical data demonstrated their beneficial effects during sepsis, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), or after aneurismal subarachnoidal hemorrhage (aSAH). Due to the heterogeneity of current studies and the lack of well-designed prospective studies, definitive conclusions for systematic and large-scale utilization in intensive care units cannot be drawn from the published evidence. Furthermore, the extent of statins side effects in critically ill patients is still unknown. For the intensive care clinician, it is a matter of individually identifying the patient who can benefit from this therapy according to the current literature. The purpose of this review is to describe the mechanisms of actions of statins and to synthesize the clinical data that underline the relevant effects of statins in the particular setting of critical care, in an attempt to guide the clinician through his daily practice.

Summary of evidence on immediate statins therapy following aneurysmal subarachnoid hemorrhage

Statins were shown to have neuroprotective effects, with reduced vasospasm and delayed ischemic deficits in statin-treated patients after aneurysmal subarachnoid hemorrhage in two small, randomized, controlled clinical trials published in 2005. This review consolidated data from available published studies evaluating statin treatment for subarachnoid hemorrhage. A literature search was conducted to identify original research studies published through October 2010 testing immediate treatment with a statin in statin-naïve patients following aneurysmal SAH. Six randomized controlled clinical trials and four observational studies were identified. Despite inconsistent results among studies, a meta-analysis of randomized controlled data showed a significant reduction in delayed ischemic deficits with statins. Effect on vasospasm was more difficult to determine, due to differences in definitions used among studies. Interpretations from observational studies were limited by the use of relatively small sample sizes, historical controls, and treatment variability.

Magnesium sulfate administration in subarachnoid hemorrhage

Magnesium offers theoretic vascular and neuroprotective benefits for patients with subarachnoid hemorrhage. An electronic literature search was conducted to identify original research studies describing intravenous magnesium treatment in patients with SAH published in English between January 1990 and October 2010. Seventeen articles were identified and reviewed, including one phase III randomized-controlled clinical trial and six phase II randomized-controlled trials. Study quality was low for most of the included studies, with the phase III trial considered to be of moderate quality. Due to inconsistently reported benefits and the occurrence of side effects, phase II data suggested that intravenous magnesium for SAH provided either no overall net benefit or uncertain trade-offs. Benefit was likewise not supported in the single phase III clinical trial.

Statins in the management of aneurysmal subarachnoid hemorrhage: an overview of animal research, observational studies, randomized controlled trials and meta-analyses

BACKGROUND

the pathophysiology of delayed neurological deficits (DNDs) following aneurysmal subarachnoid hemorrhage (SAH) is complex, and is not limited to arterial narrowing (vasospasm) and classical ischemia. Thus, combined drug approaches, or therapies with multiple effects, may have the greatest potential for benefit. Statins are known to have pleiotropic vascular effects, some of which may interrupt the pathogenesis of DNDs. Based on promising preliminary reports, many clinicians routinely administer statins to prevent DNDs.

METHODS

a systematic review was performed to identify and summarize all animal research, observational studies, randomized controlled trials (RCTs) and meta-analyses which have evaluated the use of statins in the management of SAH.

RESULTS

nine animal studies, nine observational (cohort and case-control) studies, six RCTs and three meta-analyses were identified. Animal studies have generally administered statin doses that, when adjusted for body weight, are 10-80 times larger than what is used in humans. Nevertheless, these models have consistently reported statins to reduce vasospasm and to demonstrate additional neuroprotective effects. However, observational studies have not revealed an association between statin-use and reduced DNDs or improved neurological outcomes. Results of RCTs have been inconsistent and limited by small sample size, but together suggest that statins may reduce DNDs, with no clear impact on mortality or neurological recovery. Optimal drug administration strategies (timing of initiation, most effective dose and duration) have not been clarified.

CONCLUSIONS

the role of statins in the management of patients with SAH remains unclear. Although promising, statins should not, at this time, be considered standard care.

Simvastatin re-couples dysfunctional endothelial nitric oxide synthase in experimental subarachnoid hemorrhage

Reduced endothelial nitric oxide synthase (eNOS) function has been linked to secondary complications of subarachnoid hemorrhage (SAH). We previously found that there is increased eNOS function after SAH but that it is uncoupled, leading to secondary complications such as vasospasm, microthromboembolism and neuronal apoptosis. Here we test the hypothesis that recoupling eNOS with simvastatin can prevent these complications. SAH was created in mice that were treated with vehicle or simvastatin starting 2 weeks before or 30 minutes after SAH. SAH increased phosphorylated eNOS which was prevented by pre- or post-treatment with simvastatin. Simvastatin pre-treatment also prevented the increase in eNOS monomer formation that was associated with SAH, decreased superoxide anion radical production and increased NO. These changes were associated with decreased vasospasm, microthromboemboli and neuronal injury. The data suggest that simvastatin re-couples eNOS after SAH, leading to decreased secondary complications such as vasospasm, microthromboemboli and neuronal injury.

A review of delayed ischemic neurologic deficit following aneurysmal subarachnoid hemorrhage: historical overview, current treatment, and pathophysiology

Delayed ischemic neurologic deficit (DIND) is a serious and poorly understood complication of aneurysmal subarachnoid hemorrhage. Although advances in treatment have improved prognosis for these patients, long-term clinical outcomes remain disappointing. Historically, angiographic vasospasm was thought to result in a DIND, although an increasing body of evidence suggests that this is an oversimplification, because interventions that have effectively targeted angiographic vasospasm have not improved outcome. Consequently, the relationship between angiographic vasospasm and neurologic outcome may be associative rather than causative. Although our understanding of the underlying molecular processes and pathophysiology is improving, responsible mediators or pathways have yet to be identified. The aim of this review is to summarize the key historical events that have helped shape our understanding of the pathophysiology of this phenomenon (microcirculation, autoregulation, microthrombosis, inflammation, apoptosis, spreading depolarization, oxidative stress) and to present the evidence underlying current treatment strategies (hemodynamic therapy, oral nimodipine, endovascular therapy, statins, cerebrospinal fluid drainage, thrombolysis, magnesium) and the translational and clinical research investigating DIND.

Statins in the management of patients with aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

BACKGROUND

Delayed ischemic neurological deficits (DINDs) contribute to morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). Based on promising preliminary reports, some clinicians routinely administer statins to prevent DINDs.

METHODS

Without language restriction, we searched MEDLINE, EMBASE, the Cochrane Central Register, references of review articles, proceedings of the International Stroke Conference, and gray literature sources. Studies were selected if they compared outcomes between statin-treated and untreated patients during the 2 weeks following SAH. Data were extracted and appraised independently and in duplicate, using standardized forms. Fixed or random effects models, as appropriate based on the degree of study heterogeneity, were applied to calculate summary measures.

RESULTS

Four RCTs, two "pseudo" RCTs, five cohort studies, and one case-control study met eligibility criteria. In the RCTs, which enrolled a total of 309 patients, statins were found to significantly reduce the occurrence of DINDs [OR 0.38 (0.23-0.65); P < 0.001], but not mortality [OR 0.51 (0.25-1.02); P = 0.06] or poor neurological recovery [OR 0.81 (0.49-1.32); P = 0.39]. Observational studies assessed 1,542 patients, of whom 385 received statins. Statin-use was not associated with any reduction in DINDs [OR 0.96 (0.71-1.31); P = 0.80], mortality [OR 1.16 (0.78-1.73); P = 0.47] or poor neurological recovery [OR 1.20 (0.84-1.72); P = 0.31]. When the results of all studies were combined, statins had no statistically significant effect.

CONCLUSIONS

Existing RCTs suggest that statins reduce DINDs, with a possible trend toward lower mortality. These findings are not supported by observational research. Although not assessed in all studies, current data do not indicate that statins improve neurological outcomes.

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.

Biologic effects of simvastatin in patients with aneurysmal subarachnoid hemorrhage: a double-blind, placebo-controlled randomized trial

Recently, two randomized controlled phase II studies showed that acute initiation of statin treatment directly after aneurysmal subarachnoid hemorrhage (SAH) decreases the incidence of radiologic vasospasm and clinical signs of delayed cerebral ischemia (DCI), and even reduces mortality. It was hypothesized that the beneficial effect resulted from pleiotropic effects of statins. The purpose of this study was to investigate the biologic effects of acute statin treatment in patients with SAH. We performed an exploratory single-center, prospective, randomized, double-blind, placebo-controlled trial. Patients were randomized to simvastatin 80 mg or placebo once daily. A total of 32 patients were included. There were no statistically significant differences in clinical baseline characteristics. With regard to primary outcomes, there were significant differences by treatment group for total cholesterol and low-density lipoprotein (LDL) cholesterol (P<0.0001), but not for parameters of coagulation, fibrinolysis, endothelium function, and inflammation. With regard to secondary outcomes, no differences were observed in the incidence of transcranial Doppler vasospasm, clinical signs of DCI, and poor outcome. We conclude that both the primary and secondary outcome results of this study do not support a beneficial effect of simvastatin in patients with SAH.