Clinical Burden of Angiographic Vasospasm and Its Complications After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review

INTRODUCTION

Angiographic vasospasm (VSP), the narrowing of intracranial arteries, is a complication of aneurysmal subarachnoid hemorrhage (aSAH) and often results in delayed cerebral ischemia (DCI) and cerebral infarction. The objective of this systematic review was to summarize the clinical burden of angiographic VSP and its related complications (DCI and cerebral infarction) after aSAH.

METHODS

Systematic searches of MEDLINE, Embase, and the Cochrane Library were conducted (in January 2021) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies reporting clinical outcomes of angiographic VSP and its related complications after aSAH. Study outcomes included measures of functional status (modified Rankin Scale [mRS], Glasgow Outcome Scale [GOS], extended Glasgow Outcome Scale [GOS-E], modified Barthel Index, or the modified National Institutes of Health Stroke Scale), cognitive status (Montreal Cognitive Assessment or the Mini Mental State Exam), clinical events (rebleeding), and mortality. Study selection, data extraction, and qualitative analyses were conducted.

RESULTS

Of 5704 abstracts reviewed, 110 studies were selected: 20 comparative and 39 regression-based studies were included in the qualitative synthesis, 51 descriptive studies were excluded. Most studies (51) were observational and conducted in a single country (53). The occurrence of angiographic VSP and its related complications after aSAH resulted in significantly poorer functional outcomes in three of nine comparative and 11 of 13 regression-based studies, measured by the mRS, and in five of six comparative and eight of nine regression-based studies, measured by the GOS and GOS-E. Angiographic VSP and its related complications were significantly associated with poor cognitive status in all five regression-based studies. Numerically or significantly higher mortality rates in patients with versus those without angiographic VSP and its related complications were reported in five of ten comparative studies and in eight of nine regression-based studies. Six studies looked at specific VSP populations (e.g., by severity or timing of VSP).

CONCLUSION

Patients with angiographic VSP and its related complications often had poor functional, neurological, and cognitive outcomes and reduced odds of survival both in hospital and at follow-up. We estimate that angiographic VSP and its related complications, DCI and cerebral infarction, lead to an approximately threefold higher odds of poor functional and cognitive outcomes, and about a twofold increase in the odds of death.

Risk Factors for Cerebral Vasospasm in Patients with Aneurysmal Subarachnoid Hemorrhage: A Tertiary Care Center Experience

Objectives  Cerebral vasospasm in subarachnoid hemorrhage (SAH) is associated with high morbidity and mortality. There is a lack of consensus on the risk factors leading to cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH). In this retrospective study, our objective was to determine the association of risk factors for cerebral vasospasm aSAH.

Methods  A total of 259 charts of aSAH patients consecutively admitted to the surgical intensive care unit of Hamad General Hospital from January 2007 to December 2016 were reviewed and included. The patient's demographic data, including comorbidities like hypertension (HTN), was recorded. Variables of interest included measurements of the neurological deficit on admission, the severity of SAH, treatment modality, and the initial computerized tomography scan of the head for intraventricular hemorrhage, intracerebral hemorrhage, or hydrocephalus. Multivariate analysis and multiple logistic regression analyzed the relationship to identify the association of independent variables.

Results  Out of the 259 patients, 34% ( n  = 87) suffered from cerebral vasospasm. The severity of SAH was associated with the development of cerebral vasospasm ( p  < 0.05). The presence of HTN and neurological deficits on admission were associated with an increased risk of cerebral vasospasm ( p  < 0.05, p  < 0.01, respectively). Hydrocephalus requiring treatment using external ventricular drains decreased the risk of cerebral vasospasm ( p  < 0.05). Intraventricular and intracerebral hemorrhage were not associated with cerebral vasospasm ( p  = 0.25, p  = 0.16). The endovascular treatment of cerebral aneurysms was associated with an increased risk of cerebral vasospasm ( p  < 0.05).

Conclusion  Cerebral vasospasm is common among patients admitted with aSAH. It is significantly associated with the history of HTN, the neurological deficit on admission that corelates more strongly to the motor deficit on admission, the severity of hemorrhage (modified Fischer score), and endovascular treatment. External ventricular drainage was associated with a decrease in cerebral vasospasm. The present study's findings shed light on cerebral vasospasm's risk factors in the country and the region.

Effects of Various Therapeutic Agents on Vasospasm and Functional Outcome After Aneurysmal Subarachnoid Hemorrhage-Results of a Network Meta-Analysis

BACKGROUND

Vasospasm and delayed ischemic neurologic deficits are the leading causes of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). Several therapeutic agents have been assessed in randomized controlled trials for their efficacy in reducing the incidence of vasospasm and improving functional outcome. The aim of this network meta-analysis is to compare all these therapeutic agents for their effect on functional outcome and other parameters after aSAH.

METHODS

A comprehensive search of different databases was performed to retrieve randomized controlled trials describing the effect of various therapeutic approaches on functional outcome and other parameters after aSAH.

RESULTS

Ninety-two articles were selected for full text review and 57 articles were selected for the final analysis. Nicardipine prolonged-release implants were found to be the best treatment in terms of favorable outcome (odds ratio [OR], 8.55; 95% credible interval [CrI], 1.63-56.71), decreasing mortality (OR, 0.08; 95% CrI, 0-0.82), and preventing angiographic vasospasm (OR, 0.018; 95% CrI, 0.00057-0.16). Cilostazol was found to be the second-best treatment in improving favorable outcomes (OR, 3.58; 95% CrI, 1.97-6.57) and decreasing mortality (OR, 0.41; 95% CrI, 0.12-1.15). Fasudil (OR, 0.16; 95% CrI, 0.03-0.78) was found to be the best treatment in decreasing increased vessel velocity and enoxaparin (OR, 0.25; 95% CrI, 0.057-1.0) in preventing delayed ischemic neurologic deficits.

CONCLUSIONS

Our analysis showed that nicardipine prolonged-release implants and cilostazol were associated with the best chance of improving favorable outcome and mortality in patients with aSAH. However, larger multicentric studies from other parts of the world are required to confirm these findings.

Amount of blood during the subacute phase and clot clearance rate as prognostic factors for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Delayed cerebral ischemia (DCI) is a poorly predictable complication occurring after aneurysmal subarachnoid hemorrhage (SAH) that can have dramatic functional consequences. Identifying the patients with the highest risk of DCI may help to institute more suitable monitoring and therapy. Early brain injuries and aneurysm-securing procedure complications could be regarded as confounding factors leading to severity misjudgment. After an early resuscitation phase, a subacute assessment may be more relevant to integrate the intrinsic SAH severity. A retrospective analysis was performed upon patients prospectively included in the registry of SAH patients between July 2015 to April 2020. The amount of cisternal and intraventricular blood were assessed semi-quantitatively on acute and subacute CT scans performed after early resuscitation. A clot clearance rate was calculated from their comparison. The primary endpoint was the occurrence of a DCI. A total of 349 patients were included in the study; 80 (22.9%) experienced DCI. In those patients, higher Fisher grades were observed on acute (p = 0.026) and subacute (p = 0.003) CT scans. On the subacute CT scan, patients who experienced DCI had a higher amount of blood, either at the cisternal (median Hijdra sum score: 11 vs 5, p < 0.001) or intraventricular (median Graeb score: 4 vs 2, p < 0.001) level. There was a negative linear relationship between the cisternal clot clearance rate and the risk of DCI. The assessment of the amount of subarachnoid blood and clot clearance following resuscitation after aneurysmal SAH can be useful for the prediction of neurological outcome.

Effect of Surgical Arachnoid Plasty on Functional Outcome in Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Various techniques have been performed to reduce subarachnoid clotting during aneurysmal neck clipping surgery. We considered that maintaining the physiologic cerebrospinal fluid circulation by performing arachnoid plasty after clipping during surgery would lead to the accelerated clearance of the subarachnoid clot.

METHODS

Patients in a prospectively maintained aneurysmal subarachnoid hemorrhage (aSAH) database at our institution and with aSAH that fulfilled the criteria were selected for this study. The incidence of delayed cerebral ischemia, angiographic vasospasm, 3-month functional outcome, and the amount of subarachnoid clot on computed tomography were compared between the 2 groups after matching.

RESULTS

From 2006 through 2016, 228 clipping cases met the inclusion criteria. Using propensity score matching, 89 cases of clipping without arachnoid plasty were matched to 89 cases of clipping with arachnoid plasty. Univariate analyses showed that arachnoid plasty significantly reduced the occurrence of hydrocephalus and incidence of poor outcome. Arachnoid plasty statistically significantly reduces the occurrence of hydrocephalus (odds ratio 0.267, 95% confidence interval 0.074-0.963, P < 0.05). Multivariate analysis also showed that arachnoid plasty was the factor reducing poor outcome at 3 months after aSAH (odds ratio 0.222, 95% confidence interval 0.075-0.661, P < 0.01).

CONCLUSIONS

The present study suggests that good hematoma clearance due to arachnoid formation reduced brain damage, cerebral vasospasm, and hydrocephalus, resulting in significantly fewer cases with poor functional prognosis. It therefore follows that procedures such as arachnoid plasty should be taken into consideration in order to improve outcome in surgical clipping.

Lessons from the CONSCIOUS-1 Study

After years of research on treatment of aneurysmal subarachnoid hemorrhage (aSAH), including randomized clinical trials, few treatments have been shown to be efficacious. Nevertheless, reductions in morbidity and mortality have occurred over the last decades. Reasons for the improved outcomes remain unclear. One randomized clinical trial that has been examined in detail with these questions in mind is Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1). This was a phase-2 trial testing the effect of clazosentan on angiographic vasospasm (aVSP) in patients with aSAH. Clazosentan decreased moderate to severe aVSP. There was no statistically significant effect on the extended Glasgow outcome score (GOS), although the study was not powered for this endpoint. Data from the approximately 400 patients in the study were detailed, rigorously collected and documented and were generously made available to one investigator. Post-hoc analyses were conducted which have expanded our knowledge of the management of aSAH. We review those analyses here.

Blood-Related Toxicity after Traumatic Brain Injury: Potential Targets for Neuroprotection

Emergency visits, hospitalizations, and deaths due to traumatic brain injury (TBI) have increased significantly over the past few decades. While the primary early brain trauma is highly deleterious to the brain, the secondary injury post-TBI is postulated to significantly impact mortality. The presence of blood, particularly hemoglobin, and its breakdown products and key binding proteins and receptors modulating their clearance may contribute significantly to toxicity. Heme, hemin, and iron, for example, cause membrane lipid peroxidation, generate reactive oxygen species, and sensitize cells to noxious stimuli resulting in edema, cell death, and increased morbidity and mortality. A wide range of other mechanisms such as the immune system play pivotal roles in mediating secondary injury. Effective scavenging of all of these pro-oxidant and pro-inflammatory metabolites as well as controlling maladaptive immune responses is essential for limiting toxicity and secondary injury. Hemoglobin metabolism is mediated by key molecules such as haptoglobin, heme oxygenase, hemopexin, and ferritin. Genetic variability and dysfunction affecting these pathways (e.g., haptoglobin and heme oxygenase expression) have been implicated in the difference in susceptibility of individual patients to toxicity and may be target pathways for potential therapeutic interventions in TBI. Ongoing collaborative efforts are required to decipher the complexities of blood-related toxicity in TBI with an overarching goal of providing effective treatment options to all patients with TBI.

Haemoglobin scavenging in intracranial bleeding: biology and clinical implications

Haemoglobin is released into the CNS during the breakdown of red blood cells after intracranial bleeding. Extracellular free haemoglobin is directly neurotoxic. Haemoglobin scavenging mechanisms clear haemoglobin and reduce toxicity; these mechanisms include erythrophagocytosis, haptoglobin binding of haemoglobin, haemopexin binding of haem and haem oxygenase breakdown of haem. However, the capacity of these mechanisms is limited in the CNS, and they easily become overwhelmed. Targeting of haemoglobin toxicity and scavenging is, therefore, a rational therapeutic strategy. In this Review, we summarize the neurotoxic mechanisms of extracellular haemoglobin and the peculiarities of haemoglobin scavenging pathways in the brain. Evidence for a role of haemoglobin toxicity in neurological disorders is discussed, with a focus on subarachnoid haemorrhage and intracerebral haemorrhage, and emerging treatment strategies based on the molecular pathways involved are considered. By focusing on a fundamental biological commonality between diverse neurological conditions, we aim to encourage the application of knowledge of haemoglobin toxicity and scavenging across various conditions. We also hope that the principles highlighted will stimulate research to explore the potential of the pathways discussed. Finally, we present a consensus opinion on the research priorities that will help to bring about clinical benefits.

Radiological scales predicting delayed cerebral ischemia in subarachnoid hemorrhage: systematic review and meta-analysis

PURPOSE

Delayed cerebral ischemia (DCI) is a severe complication of aneurysmal subarachnoid hemorrhage (aSAH). The extent of subarachnoid blood is a strong predictor of DCI and is frequently estimated with the Fisher scale, modified Fisher scale, or Hijdra sum score. It is unclear which scale has the strongest association with clinical DCI. To evaluate this, we performed a systematic review of the literature.

METHODS

We performed a MEDLINE and EMBASE search from 1980 to 20th of June 2017. Radiological grade and occurrence of clinical DCI were extracted along with odds ratios (ORs) for DCI. When possible, pooled ORs with 95% confidence intervals were calculated per grade increase on the radiological scale.

RESULTS

Fifty-three studies were included. The Fisher scale was significantly associated with DCI in 62% of the studies compared to 88-100% for the other scales. In studies using the Fisher scale, Fisher 3 had the strongest association with DCI (pooled OR 3.21 (1.87-5.49)). In studies using the modified Fisher score, DCI occurred most frequently (42%) in modified Fisher 4. No pooled OR could be calculated for the other scales.

CONCLUSION

The Fisher scale, modified Fisher scale, and Hijdra sum score are all associated with clinical DCI. The risk of DCI, however, does not increase with increasing Fisher grade as opposed to the modified Fisher scale. Furthermore, the modified Fisher scale was more commonly significantly associated with DCI than the Fisher scale, which may advocate using the modified Fisher in future SAH-related studies.

Predictors of Postoperative Cerebral Ischemia in Patients with Ruptured Anterior Communicating Artery Aneurysms

OBJECTIVE

Cerebral ischemia is a major contributor to poor outcome after ruptured anterior communicating artery aneurysms (ACoAs), and is not well classified. In this article, we develop a classification and identify risk factors of cerebral ischemia after ruptured ACoAs.

METHODS

Three hundred sixty patients with ruptured ACoAs undergoing microsurgical clipping were collected. Sex, age, smoking status, Hunt-Hess grade, Fisher grade, hospital stay, surgical timing, hypertension, diabetes, postoperative cerebral ischemia, and postoperative modified Rankin Scale score were collected. Postoperative ischemic changes are classified according to a novel grade (ischemic grade I-IV).

RESULTS

Predictive factors of postoperative ischemia (grade I-IV) included sex (odds ratio [OR], 1.956; 95% confidence interval [CI], 1.262-3.032; P = 0.003) and Fisher grade (OR, 1.813; 95% CI, 1.144-2.871; P = 0.011). Male sex had a tendency to develop postoperative cerebral ischemia (61.3% in the ischemia group vs. 45.7% in the nonischemia group), while surgical timing did not. However, in patients with postoperative ischemia, early surgery within 3 days (OR, 3.334; 95% CI, 1.411-7.879; P = 0.006) and advanced age greater than 55 years (OR, 2.783; 95% CI, 1.214-6.382; P = 0.016) were risk factors for postoperative neurologic deficits (grade III-IV).

CONCLUSIONS

Male sex and higher Fisher grade predict postoperative ischemia (grade I-IV), whereas surgical timing does not. However, in patients with postoperative cerebral ischemia, early surgery within 3 days and age greater than 55 years can increase the frequency of postoperative neurological deficits (grade III-IV). Older male patients undergoing early microsurgery had a tendency to develop neurologic deficits.

A Partial Least-Squares Analysis of Health-Related Quality-of-Life Outcomes After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Individuals who have aneurysmal subarachnoid hemorrhages (SAHs) experience decreased health-related qualities of life (HRQoLs) that persist after the primary insult.

OBJECTIVE

To identify clinical variables that concurrently associate with HRQoL outcomes by using a partial least-squares approach, which has the distinct advantage of explaining multidimensional variance where predictor variables may be highly collinear.

METHODS

Data collected from the CONSCIOUS-1 trial was used to extract 29 clinical variables including SAH presentation, hospital procedures, and demographic information in addition to 5 HRQoL outcome variables for 256 individuals. A partial least-squares analysis was performed by calculating a heterogeneous correlation matrix and applying singular value decomposition to determine components that best represent the correlations between the 2 sets of variables. Bootstrapping was used to estimate statistical significance.

RESULTS

The first 2 components accounting for 81.6% and 7.8% of the total variance revealed significant associations between clinical predictors and HRQoL outcomes. The first component identified associations between disability in self-care with longer durations of critical care stay, invasive intracranial monitoring, ventricular drain time, poorer clinical grade on presentation, greater amounts of cerebral spinal fluid drainage, and a history of hypertension. The second component identified associations between disability due to pain and discomfort as well as anxiety and depression with greater body mass index, abnormal heart rate, longer durations of deep sedation and critical care, and higher World Federation of Neurosurgical Societies and Hijdra scores.

CONCLUSION

By applying a data-driven, multivariate approach, we identified robust associations between SAH clinical presentations and HRQoL outcomes.

ABBREVIATIONS

EQ-VAS, EuroQoL visual analog scaleHRQoL, health-related quality of lifeICU, intensive care unitIVH, intraventricular hemorrhagePLS, partial least squaresSAH, subarachnoid hemorrhageSVD, singular value decompositionWFNS, World Federation of Neurosurgical Societies.

Aneurysmal Subarachnoid Hemorrhage in Pregnancy-Case Series, Review, and Pooled Data Analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) during pregnancy represents an important cause of maternal and fetal morbidity and mortality. Approaches to diagnostics and treatment are still controversial, and there are only a limited number of cases described in the literature. Our study examines the management of aSAH in pregnant patients, creating a case series by combining patients from our hospital records with those from the limited available literature.

METHODS

Data collected from Addenbrooke's Hospital records and cases published between January 1995 and January 2015 were studied. Chi-square test, exact Fisher's test, and chi-square test for trend were used for analyzing categorical data, while the t-test and Mann-Whitney-Wilcoxon test were used for continuous data.

RESULTS

Fifty-two patients were included. The mean age was 31.47 ± 5.80, and most patients were in their third trimester. A univariate pooled data analysis suggested that the maternal outcome may depend on the mother's age, mother's Hunt and Hess scale score, Glasgow Coma Scale at arrival, treatment modality for the aneurysm, mode, and timing of delivery. However, at the multivariate analysis only the presence of general complications resulted in a significant impact on maternal outcome.

CONCLUSIONS

Ruptured aneurysms in pregnant patients with aSAH may be safely secured in a timely manner. The diagnostic and treatment strategy for each of these patients should consider peculiar maternal and obstetric factors and requires a multidisciplinary assessment involving obstetrics, neurosurgeons, and intensivists. Considering the observed statistical power of our series, our findings should be taken with caution and should be supported by further systematic data collection.

Risk Factors for Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage: A Review of the Literature

OBJECTIVE

To examine the literature on risk factors for cerebral vasospasm (CV), one of the most serious complications following aneurysmal subarachnoid hemorrhage (SAH), with special reference to the definition of CV.

METHODS

Using standard search engines, including PubMed, the medical literature on risk factors for CV after SAH was reviewed, and the best definition representative of CV was searched.

RESULTS

Severe SAH evident on computed tomography scan was the only consistent risk factor for CV after SAH. Effects of risk factors on CV, including age, clinical grade, rebleeding, intraventricular or intracerebral hemorrhage on computed tomography scan, acute hydrocephalus, aneurysm site and size, leukocytosis, interleukin-6 level, and cardiac abnormalities, appeared to be associated with the severity of SAH rather than each having a direct effect. Cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram were associated with CV without any relationship to SAH severity. With regard to parameters representative of CV, the grade of angiographic vasospasm (i.e., the degree of arterial narrowing evident on angiography) was the most adequate. Nevertheless, few reports on the risk factors associated with angiographic vasospasm grade have been reported to date.

CONCLUSIONS

Severe SAH evident on computed tomography scan appears to be a definite risk factor for CV after SAH, followed by cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram. To understand the pathogenesis of CV, further studies on the relationships between risk factors, especially factors not related to the severity of SAH, and angiographic vasospasm grade are necessary.

Operative complications and differences in outcome after clipping and coiling of ruptured intracranial aneurysms

OBJECT

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with substantial morbidity and mortality, with better outcomes reported following endovascular coiling compared with neurosurgical clipping of the aneurysm. The authors evaluated the contribution of perioperative complications and neurological decline to patient outcomes after both aneurysm-securing procedures.

METHODS

A post hoc analysis of perioperative complications from the Clazosentan to Overcome Neurological iSChemia and Infarction Occurring after Subarachnoid hemorrhage (CONSCIOUS-1) study was performed. Glasgow Coma Scale (GCS) scores for patients who underwent neurosurgical clipping and endovascular coiling were analyzed preoperatively and each day following the procedure. Complications associated with a decline in postoperative GCS scores were identified for both cohorts. Because patients were not randomized to the aneurysm-securing procedures, propensity-score matching was performed to balance selected covariates between the 2 cohorts. Using a multivariate logistic regression, the authors evaluated whether a perioperative decline in GCS scores was associated with long-term outcomes on the extended Glasgow Outcome Scale (eGOS).

RESULTS

Among all enrolled subjects, as well as the propensity-matched cohort, patients who underwent clipping had a significantly greater decline in their GCS scores postoperatively than patients who underwent coiling (p = 0.0024). Multivariate analysis revealed that intraoperative hypertension (p = 0.011) and intraoperative induction of hypotension (p = 0.0044) were associated with a decline in GCS scores for patients undergoing clipping. Perioperative thromboembolism was associated with postoperative GCS decline for patients undergoing coiling (p = 0.03). On multivariate logistic regression, postoperative neurological deterioration was strongly associated with a poor eGOS score at 3 months (OR 0.86, 95% CI 0.78-0.95, p = 0.0032).

CONCLUSIONS

Neurosurgical clipping following aSAH is associated with a greater perioperative decline in GCS scores than endovascular coiling, which is in turn associated with poorer long-term outcomes. These findings provide novel insight into putative mechanisms of improved outcomes following coiling, highlighting the potential importance of perioperative factors when comparing outcomes between clipping and coiling and the need to mitigate the morbidity of surgical strategies following aSAH.

The network topology of aneurysmal subarachnoid haemorrhage

OBJECTIVE

Network analysis is an emerging tool for the study of complex systems. In the current report, the cascade of physiological and neurological changes following aneurysmal subarachnoid haemorrhage (SAH) was modelled as a complex system of interacting parameters. Graph theoretical analysis was then applied to identify parameters at critical topological junctions of the network, which may represent the most effective therapeutic targets.

METHODS

Correlation matrices were calculated using a combination of Pearson, polyserial and polychoric regressions among 50 variables collected from 120 participants (38 male; mean age 51 years) included in the CONSCIOUS-1 trial. Graph theoretical analysis was performed to identify important topological features within the network formed by the interactions among these variables. Non-parametric resampling was applied to determine thresholds for significance.

RESULTS

Several critical network hubs were identified, including the incidence of delayed ischaemic neurological deficit (DIND), anaemia and hypoalbuminaemia/hypoproteinaemia. While not significant hubs, World Federation of Neurosurgical Societies (WFNS) score and use of rescue therapy had widespread connections within the network. Patient sex and history of hypertension also strongly clustered with other variables. A subnetwork (module) was also identified, which was related to neurological outcomes including WFNS score, angiographic vasospasm, DIND, use of rescue therapy and hydrocephalus.

INTERPRETATION

Using graph theoretical analysis, we identify critical network topologies following SAH, which may serve as useful therapeutic targets. Importantly, we demonstrate that network analysis is a robust method to model complex interactions following SAH.

TRIAL REGISTRATION NUMBER

URL: http://www.clinicaltrials.gov; Identifier: NCT00111085.

The effects of fluid balance and colloid administration on outcomes in patients with aneurysmal subarachnoid hemorrhage: a propensity score-matched analysis

BACKGROUND

Delayed ischemic neurological deficit (DIND) following aneurysmal subarachnoid hemorrhage (SAH) remains a significant cause of mortality and disability. The administration of colloids and the induction of a positive fluid balance during the vasospasm risk period remain controversial. Here, we compared DIND and outcomes among propensity score-matched cohorts who did and did not receive colloids and also tested the effect of a positive fluid balance on these endpoints.

METHODS

Exploratory analysis was performed on 413 patients enrolled in CONSCIOUS-1, a prospective randomized trial of clazosentan for the prevention of angiographic vasospasm. Propensity score matching was performed on the basis of age, gender, pre-existing heart conditions, hypertension, nicotine use, World Federation of Neurosurgical Societies scores, aneurysm location, clazosentan treatment, subarachnoid clot burden, and severity of angiographic vasospasm. Inferential statistics were used for group-wise comparisons.

RESULTS

One hundred twenty-three subjects were matched (41 received colloids, whereas 82 did not). The covariate balance and propensity score distributions were acceptable. There was no difference between the groups with respect to DIND (17 vs. 22%; p = 0.64) or the presence (48 vs. 51%; p = 0.71) or volume of delayed infarcts (volume >7.5 cm3; 62 vs. 48%; p = 0.41). Similarly, no differences were found on multivariate analysis between patients who did and did not have a positive fluid balance, although patients with severe angiographic vasospasm had more delayed infarcts with a negative fluid balance (p = 0.01). Among all subjects, the administration of colloids and a positive fluid balance were associated with worse outcomes on the NIHSS (p = 0.04) and modified Rankin (p = 0.02) scales, respectively.

CONCLUSIONS

Colloid administration and induction of a positive fluid balance during the vasospasm risk period may be associated with poor outcomes in specific patient groups. Patient selection is of utmost importance when managing the fluid status of patients with aneurysmal SAH.

Patient phenotypes associated with outcomes after aneurysmal subarachnoid hemorrhage: a principal component analysis

BACKGROUND AND PURPOSE

Predictors of outcome after aneurysmal subarachnoid hemorrhage have been determined previously through hypothesis-driven methods that often exclude putative covariates and require a priori knowledge of potential confounders. Here, we apply a data-driven approach, principal component analysis, to identify baseline patient phenotypes that may predict neurological outcomes.

METHODS

Principal component analysis was performed on 120 subjects enrolled in a prospective randomized trial of clazosentan for the prevention of angiographic vasospasm. Correlation matrices were created using a combination of Pearson, polyserial, and polychoric regressions among 46 variables. Scores of significant components (with eigenvalues>1) were included in multivariate logistic regression models with incidence of severe angiographic vasospasm, delayed ischemic neurological deficit, and long-term outcome as outcomes of interest.

RESULTS

Sixteen significant principal components accounting for 74.6% of the variance were identified. A single component dominated by the patients' initial hemodynamic status, World Federation of Neurosurgical Societies score, neurological injury, and initial neutrophil/leukocyte counts was significantly associated with poor outcome. Two additional components were associated with angiographic vasospasm, of which one was also associated with delayed ischemic neurological deficit. The first was dominated by the aneurysm-securing procedure, subarachnoid clot clearance, and intracerebral hemorrhage, whereas the second had high contributions from markers of anemia and albumin levels.

CONCLUSIONS

Principal component analysis, a data-driven approach, identified patient phenotypes that are associated with worse neurological outcomes. Such data reduction methods may provide a better approximation of unique patient phenotypes and may inform clinical care as well as patient recruitment into clinical trials.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00111085.

Early predictors of prolonged stay in a critical care unit following aneurysmal subarachnoid hemorrhage

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a neurologic emergency that typically warrants initial monitoring in a critical care setting. The aim of this study is to identify clinical and radiologic features on admission that predict a protracted critical care admission following aSAH.

METHODS

Exploratory posthoc analysis was performed on the 413 patients enrolled in Clazosentan to Overcome Neurological iSChemia and Infarction OccUrring after Subarachnoid hemorrhage (CONSCIOUS-1), a prospective randomized control trial of clazosentan for the prevention of vasospasm after aSAH. The association between potential clinical and radiographic covariates, and the length of stay (LOS) in a critical care unit after aSAH was determined using a Cox proportional hazards model. Covariates with a significance level of p < 0.20, on univariate analysis, were entered into a multivariate forward conditional analysis to identify independent predictors of prolonged LOS.

RESULTS

The mean LOS was 12.6 ± 10.6 days. On multivariate analysis, age (hazard ratio [HR] 1.01, 95 % confidence interval [CI] 1.00-1.02; p = 0.032), a history of hypertension (HR 1.30, CI 1.01-1.67; p = 0.045), and a World Federation of Neurosurgical Societies Score of IV-V on admission (HR 1.38, CI 1.05-1.81; p = 0.02) were the clinical features associated with a greater critical care LOS following aSAH. Intracerebral hemorrhage (HR 1.50, CI 1.03-2.21; p = 0.004) and increasing intraventricular clot burden (HR 1.08, CI 1.03-1.14; p = 0.037) on admission computed tomography were the radiologic features associated with prolonged LOS.

CONCLUSIONS

We have identified several early risk factors associated with a prolonged critical care stay following aSAH.

Dissociation of vasospasm-related morbidity and outcomes in patients with aneurysmal subarachnoid hemorrhage treated with clazosentan: a meta-analysis of randomized controlled trials

OBJECT

Clazosentan therapy after aneurysmal subarachnoid hemorrhage (SAH) has been found to be effective in reducing the incidence of vasospasm in randomized controlled trials. However, while vasospasm-related morbidity, including delayed ischemic neurological deficits (DINDs) and delayed cerebral infarctions, was consistently decreased, statistical significance was not demonstrated and outcomes were not affected by clazosentan treatment. The objective of this meta-analysis was to determine whether clazosentan treatment after aneurysmal SAH significantly reduced the incidence of DINDs and delayed cerebral infarctions and improved outcomes.

METHODS

All randomized controlled trials investigating the effect of clazosentan were retrieved via searches with sensitive and specific terms. Six variables were abstracted after the assessment of the methodological quality of the trials. Analyses were performed following the method guidelines of the Cochrane Back Review Group.

RESULTS

Four randomized, placebo-controlled trials met eligibility criteria, enrolling a total of 2181 patients. The meta-analysis demonstrated a significant decrease in the incidence of DINDs (relative risk [RR] 0.76 [95% CI 0.62-0.92]) and delayed cerebral infarction (RR 0.79 [95% CI 0.63-1.00]) in patients treated with clazosentan after aneurysmal SAH. However, this treatment regimen was not shown to outcomes including functional outcomes measured by Glasgow Outcome Scale-Extended (RR 1.12 [95% CI 0.96-1.30]) or mortality (RR 1.02 [95%CI 0.70-1.49]). Adverse events, including pulmonary complications, anemia, and hypotension, were all significantly increased in patients who received clazosentan therapy.

CONCLUSIONS

The results of the present meta-analysis show that treatment with clazosentan after aneurysmal SAH significantly reduced the incidence of the vasospasm-related DINDs and delayed cerebral infarctions, but did not improve poor neurological outcomes in patients with aneurysmal SAH. Further study is required to elucidate the dissociation between vasospasm-related morbidity and outcomes.