Mervyn D.I. Vergouwen

Critical Care Management of Patients Following Aneurysmal Subarachnoid Hemorrhage: Recommendations from the Neurocritical Care Society’s Multidisciplinary Consensus Conference

Subarachnoid hemorrhage (SAH) is an acute cerebrovascular event which can have devastating effects on the central nervous system as well as a profound impact on several other organs. SAH patients are routinely admitted to an intensive care unit and are cared for by a multidisciplinary team. A lack of high quality data has led to numerous approaches to management and limited guidance on choosing among them. Existing guidelines emphasize risk factors, prevention, natural history, and prevention of rebleeding, but provide limited discussion of the complex critical care issues involved in the care of SAH patients. The Neurocritical Care Society organized an international, multidisciplinary consensus conference on the critical care management of SAH to address this need. Experts from neurocritical care, neurosurgery, neurology, interventional neuroradiology, and neuroanesthesiology from Europe and North America were recruited based on their publications and expertise. A jury of four experienced neurointensivists was selected for their experience in clinical investigations and development of practice guidelines. Recommendations were developed based on literature review using the GRADE system, discussion integrating the literature with the collective experience of the participants and critical review by an impartial jury. Recommendations were developed using the GRADE system. Emphasis was placed on the principle that recommendations should be based not only on the quality of the data but also tradeoffs and translation into practice. Strong consideration was given to providing guidance and recommendations for all issues faced in the daily management of SAH patients, even in the absence of high quality data.

Definition of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage as an Outcome Event in Clinical Trials and Observational Studies Proposal of a Multidisciplinary Research Group

Background and Purpose— In clinical trials and observational studies there is considerable inconsistency in the use of definitions to describe delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage. A major cause for this inconsistency is the combining of radiographic evidence of vasospasm with clinical features of cerebral ischemia, although multiple factors may contribute to DCI. The second issue is the variability and overlap of terms used to describe each phenomenon. This makes comparisons among studies difficult. Methods— An international ad hoc panel of experts involved in subarachnoid hemorrhage research developed and proposed a definition of DCI to be used as an outcome measure in clinical trials and observational studies. We used a consensus-building approach. Results— It is proposed that in observational studies and clinical trials aiming to investigate strategies to prevent DCI, the 2 main outcome measures should be: (1) cerebral infarction identified on CT or MRI or proven at autopsy, after exclusion of procedure-related infarctions; and (2) functional outcome. Secondary outcome measure should be clinical deterioration caused by DCI, after exclusion of other potential causes of clinical deterioration. Vasospasm on angiography or transcranial Doppler can also be used as an outcome measure to investigate proof of concept but should be interpreted in conjunction with DCI or functional outcome. Conclusion— The proposed measures reflect the most relevant morphological and clinical features of DCI without regard to pathogenesis to be used as an outcome measure in clinical trials and observational studies.

Microthrombosis after aneurysmal subarachnoid hemorrhage: an additional explanation for delayed cerebral ischemia.

Patients with aneurysmal subarachnoid hemorrhage (SAH) who experience delayed cerebral ischemia (DCI) have an increased risk of poor outcome. Delayed cerebral ischemia is considered to be caused by vasospasm. However, not all patients with DCI have vasospasm. Inversely, not all patients with vasospasm develop clinical symptoms and signs of DCI. In the past, treatments aiming at vasospasm were not successful in preventing ischemia. The purpose of this review is to give an overview of clinical data showing that DCI cannot always be attributed to vasospasm, and to present an in-depth analysis of clinical and autopsy studies on the role of microthrombosis in the pathogenesis of DCI. Clinical studies show that DCI is associated with an activation of the coagulation cascade within a few days after SAH, preceding the time window during which vasospasm occurs. Furthermore, impaired fibrinolytic activity, and inflammatory and endothelium-related processes, lead to the formation of microthrombi, which ultimately result in DCI. The presence of microthrombi is confirmed by autopsy studies. Insight in the pathophysiology of DCI is crucial for the development of effective therapies against this complication. Because multiple pathways are involved, future research should focus on drugs with pleiotropic effects.

Cerebral Infarction After Subarachnoid Hemorrhage Contributes to Poor Outcome by Vasospasm-Dependent and -Independent Effects

Background and Purpose— The pathogenesis of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage remains incompletely understood. It is generally assumed that it is caused by angiographic vasospasm. Our aim was to clarify the relationship among angiographic vasospasm, neurological worsening, cerebral infarction, and poor outcome and to investigate whether cerebral infarction also contributes to poor outcome by vasospasm-independent effects. Methods— This exploratory analysis used data from 413 patients included in the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) trial. We studied the incidence of neurological worsening, cerebral infarction, and poor outcome in patients with and without angiographic vasospasm. Path analysis implemented by structural equation modeling was performed to determine direct and indirect path coefficients. Results— Of the 194 patients with moderate to severe vasospasm, 43% had neurological worsening of any cause, 20% had cerebral infarction, and 46% poor outcome. Path coefficients for direct effects on poor outcome were 0.20 for World Federation of Neurological Surgeons Grade 4 to 5, 0.13 for history of hypertension, 0.19 for angiographic vasospasm, 0.16 for neurological worsening, and 0.11 for new cerebral infarction. Cerebral infarction contributed to poor outcome by vasospasm-dependent and -independent effects. Conclusions— Our data show that the majority of patients with moderate to severe angiographic vasospasm did not have neurological worsening of any cause or cerebral infarction. Besides, cerebral infarction also has a direct effect on outcome independent of angiographic vasospasm. This suggests that other coexisting factors might be involved in the pathogenesis of delayed cerebral ischemia, which should also be an important research target to improve outcome after subarachnoid hemorrhage.

Statin Treatment and the Occurrence of Hemorrhagic Stroke in Patients With a History of Cerebrovascular Disease

Background and Purpose— The recently published Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) study showed that statins exert a marginally beneficial effect on stroke prevention in patients with a history of cerebrovascular disease. Interestingly, the magnitude of the beneficial effect shown in this study is smaller than in similar studies, which included patients without a history of cerebrovascular disease. In SPARCL, an increased occurrence of hemorrhagic strokes in patients on statin treatment was observed, an effect that was also earlier described in the Heart Protection Study in a subgroup of patients with a history of cerebrovascular disease. The purpose of this systematic review was therefore to investigate the effect of statin treatment on the occurrence of ischemic and hemorrhagic strokes in patients with a history of cerebrovascular disease. Methods— We systematically searched the PUBMED database for the combination of the variables “statin” AND “stroke.” Furthermore, we searched for relevant studies in the Cochrane Library and Cochrane Central Register of Controlled Trials and handsearched citations. Pooled effect sizes were expressed in relative risk estimates with corresponding 95% CIs. Results— Four studies were included investigating the effect of statins in 8832 patients with a history of cerebrovascular disease. The pooled relative risk for statin users of overall stroke during follow-up was 0.88 (95% CI: 0.78 to 0.99). The pooled relative risk of ischemic stroke was 0.80 (95% CI: 0.70 to 0.92) and of hemorrhagic stroke 1.73 (95% CI: 1.19 to 2.50). Conclusion— In patients with a history of cerebrovascular disease, statins clearly decrease the risk of ischemic stroke. However, this beneficial effect is partly lost by an increased risk of hemorrhagic stroke.

Effect of Statin Treatment on Vasospasm, Delayed Cerebral Ischemia, and Functional Outcome in Patients With Aneurysmal Subarachnoid Hemorrhage A Systematic Review and Meta-Analysis Update

Background and Purpose— A recent meta-analysis investigating the efficacy of statin treatment in patients with aneurysmal subarachnoid hemorrhage reported a reduced incidence of vasospasm, delayed cerebral ischemia, and mortality in statin-treated patients. However, the meta-analysis was criticized for its methodology, and several retrospective studies found no beneficial effect. We present the results of a new systematic review, which differs from the previous systematic review in its methodology, and by inclusion of the results of a fourth randomized, placebo-controlled trial. Summary of Review— All randomized, placebo-controlled trials investigating the effect of statins on vasospasm, delayed cerebral ischemia, and functional outcome in patients with aneurysmal subarachnoid hemorrhage were included. Outcomes were the number of patients with transcranial Doppler vasospasm, delayed cerebral ischemia, poor outcome, and mortality during follow-up. Effect sizes were expressed in (pooled) risk ratio estimates. Data were pooled using random-effects models. Results— In 4 studies, a total of 190 patients were included. No statistically significant effect was observed on transcranial Doppler vasospasm (pooled risk ratio, 0.99 [95% CI, 0.66 to 1.48]), delayed cerebral ischemia (pooled risk ratio, 0.57 [95% CI, 0.29 to 1.13]), poor outcome (pooled risk ratio, 0.92 [95% CI, 0.68 to 1.24]), or mortality (pooled risk ratio, 0.37 [95% CI, 0.13 to 1.10]). Conclusion— The results of the present systematic review do not lend statistically significant support to the finding of a beneficial effect of statins in patients with aneurysmal subarachnoid hemorrhage as reported in a previous meta-analysis.

Safety and Functional Outcome of Thrombolysis in Dissection-Related Ischemic Stroke A Meta-Analysis of Individual Patient Data

Background and Purpose— The safety and efficacy of thrombolysis in cervical artery dissection (CAD) are controversial. The aim of this meta-analysis was to pool all individual patient data and provide a valid estimate of safety and outcome of thrombolysis in CAD. Methods— We performed a systematic literature search on intravenous and intra-arterial thrombolysis in CAD. We calculated the rates of pooled symptomatic intracranial hemorrhage and mortality and indirectly compared them with matched controls from the Safe Implementation of Thrombolysis in Stroke–International Stroke Thrombolysis Register. We applied multivariate regression models to identify predictors of excellent (modified Rankin Scale=0 to 1) and favorable (modified Rankin Scale=0 to 2) outcome. Results— We obtained individual patient data of 180 patients from 14 retrospective series and 22 case reports. Patients were predominantly female (68%), with a mean±SD age of 46±11 years. Most patients presented with severe stroke (median National Institutes of Health Stroke Scale score=16). Treatment was intravenous thrombolysis in 67% and intra-arterial thrombolysis in 33%. Median follow-up was 3 months. The pooled symptomatic intracranial hemorrhage rate was 3.1% (95% CI, 1.3 to 7.2). Overall mortality was 8.1% (95% CI, 4.9 to 13.2), and 41.0% (95% CI, 31.4 to 51.4) had an excellent outcome. Stroke severity was a strong predictor of outcome. Overlapping confidence intervals of end points indicated no relevant differences with matched controls from the Safe Implementation of Thrombolysis in Stroke–International Stroke Thrombolysis Register. Conclusions— Safety and outcome of thrombolysis in patients with CAD-related stroke appear similar to those for stroke from all causes. Based on our findings, thrombolysis should not be withheld in patients with CAD.

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 (ISRCTN45662651).

Lower incidence of cerebral infarction correlates with improved functional outcome after aneurysmal subarachnoid hemorrhage

Despite an undisputed association between vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage (SAH), there is debate if this association implies causality. It has been suggested that cerebral infarction is a better outcome measure than vasospasm in clinical trials and observational studies. To further investigate the relationship between infarction and outcome, we performed a systematic review and meta-analysis of all randomized, double-blind, placebo-controlled trials that studied the efficacy of pharmaceutical preventive strategies in SAH patients, and had both cerebral infarction and clinical outcome as outcome events. Effect sizes were expressed in (pooled) risk ratio (RR) estimates with corresponding 95% confidence intervals (CIs). Sensitivity analyses were performed for studies with a low risk of bias and for those who reported outcome at 3 months after SAH. Twenty-four studies including 8,552 patients were included. Pharmaceutical treatments decreased the incidence of both cerebral infarction (RR: 0.83; 95% CI: 0.74 to 0.93) and of poor functional outcome (RR: 0.92; 95% CI: 0.86 to 0.98). The sensitivity analyses did not change the results essentially. These data suggest that the previously observed association between cerebral infarction and functional outcome implies causality, and that cerebral infarction is a better outcome measure than vasospasm in clinical trials and observational studies.

The unruptured intracranial aneurysm treatment score A multidisciplinary consensus

Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (vr*) (vr* = 0 indicating excellent agreement and vr* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1–4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1–4.4) for panel members and 4.5 (95% CI 4.3–4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1–4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9–4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (vr*) for both cohorts was 0.026 (95% CI 0.019–0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.