The Role of Platelet Activation and Inflammation in Early Brain Injury Following Subarachnoid Hemorrhage

Use of thrombocyte count dynamics after aneurysmal subarachnoid hemorrhage to predict cerebral vasospasm and delayed cerebral ischemia: a retrospective monocentric cohort study

Cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) are critical complications following aneurysmal subarachnoid hemorrhage (aSAH), contributing to substantial morbidity and mortality. This retrospective cohort study investigated thrombocyte count (TC) dynamics as a potential marker for predicting CVS and DCI in 233 adult patients with aSAH. Parameters including TC, C-reactive protein, hematocrit, CVS, and DCI were analyzed using logistic regression, Spearman correlation, and time-to-event analysis. CVS and DCI occurred in 71.1% and 41.2% of patients, respectively. A relative thrombocyte count decrease greater than 12.6% within the early post-aSAH period was significantly associated with increased risks of CVS (p < 0.001; 95% CI 4.74-25.3) and DCI (p = 0.003; 95% CI 1.39-5.43). Temporal analysis revealed that greater TC decrease correlated with earlier CVS onset (p = 0.00016; R=-0.28), with a median of three days from the minimum TC to CVS onset. This association suggests a potential diagnostic window for early detection and intervention if validated in prospective studies.

Role of the platelet-lymphocyte ratio as a prognostic indicator in patients with intracranial hemorrhage: A systematic review and meta-analysis

BACKGROUND

The prognostic value of platelet-lymphocyte ratio (PLR) in ischemic stroke had been investigated in previous studies. However, the results of studies on PLR in patients with intracranial hemorrhage (ICH) are inconsistent. We aimed to conduct a meta-analysis to determine the prognostic value of PLR in predicting functional outcome and mortality in patients with ICH.

METHODS

We searched the databases of PubMed, Embase, the Cochrane Library, and CNKI for relevant studies up to 10th June 2024. The Newcastle Ottawa Quality Assessment Scale (NOS) was applied to evaluate the quality of the included studies. We calculated the pooled odds ratios (OR) with 95% confidence intervals (CI) between PLR and both functional outcome (as measured by the modified Rankin Scale, mRS) as well as mortality. Poor functional outcomes were defined as mRS > 2.

RESULTS

A total of 6 studies with 2992 patients were included. The random effects meta-analysis demonstrated that elevated PLR exhibited an association with poor functional outcome in patients with ICH (OR = 1.69; 95% CI [1.39-2.07]; P<0.0001; I2 = 24%). Similarly, elevated PLR was associated with mortality in patients with ICH (OR = 1.65; 95% CI [1.12-2.43]; P = 0.01; I2 = 31%).

CONCLUSION

This study suggested that elevated PLR was significantly associated with poor functional outcome (mRS>2) and increased mortality, indicating that elevated PLR could serve as a reliable a prognostic factor for unfavorable clinical outcomes in patients with ICH. It is advisable to conduct extensive prospective investigations across diverse ethnic backgrounds to verify the accuracy of this correlation prior to its utilization in clinical settings.

Safety and efficacy of staged primary coiling followed by delayed flow diversion of ruptured intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

Ruptured intracranial aneurysms lead to significant mortality and morbidity. Recent advancements have suggested staged coiling with subsequent flow diverter stent placement may reduce the risk of hemorrhage with dual antiplatelet therapy (DAPT) or stent thrombosis in the acute inflammatory phase after aneurysm rupture while still appropriately mitigating risk of aneurysmal rehemorrhage.

MATERIALS AND METHODS

A systematic review and single-arm meta-analysis was conducted. Studies reporting patients receiving coiling followed by delayed flow diverter placement on a separate day were included.

RESULTS

Five studies, comprising 94 patients, were included for meta-analysis. Average time between procedures ranged from 9.8 to 169 days; 24% (95% CI: 10-41%) of patients had a poor functional neurologic outcome (modified Rankin Scale > 2) at discharge compared to 4% (0-11%) at last follow-up. There was one incidence of rehemorrhage between treatments, 0% (0-4%). Vasospasm after coiling was the most common adverse event, 16% (1-41%). There was low risk of ischemic complications [1% (0-8%) with coil placement and 5% (1-11%) with stent placement]. Intraprocedural intracranial hemorrhage was also rare (two patients during coil placement; no cases during stent placement). There were no significant differences if flow diversion was performed less than or greater than 100 days from coiling.

CONCLUSIONS

Our study highlights the benefit of primary coiling with staged flow diversion for the management of ruptured intracranial aneurysms with a low risk for complications. Namely, the rate of rebleeding between treatments was exceptionally low. We advocate for the greater consideration of this treatment combination in the treatment of ruptured intracranial aneurysms.

Impact of analgesic regimen on patient outcome following subarachnoid hemorrhage: positive adjuvant effects of metamizole

INTRODUCTION

Various analgesics are used to control intense headaches in patients following subarachnoid hemorrhage. In addition to pain control, it has been shown that some analgesics can affect various pathophysiological cascades. Therefore, we devised a study to assess whether the use of metamizole has a significant impact on the development of ischemic complications, hydrocephalus, and the overall outcome in patients following aneurysmal subarachnoid hemorrhage in the context of the other non-opioids and opioids effects.

METHODS

In our retrospective, single-center cohort study, we enrolled 192 patients diagnosed with subarachnoid hemorrhage. We recorded their initial clinical status, comorbidities, and the daily dosage of analgesics over 14 days of hospitalization after the onset of subarachnoid hemorrhage. Using univariate and subsequent multivariate logistic regression analysis, we assessed the influence of various factors, including analgesics, on the development of delayed cerebral ischemia and hydrocephalus, as well as on 2-week and 6-month outcomes.

RESULTS

Although the administration of non-opioids, in general, had no effect on the development of delayed cerebral ischemia or hydrocephalus, the use of metamizole as the main analgesic was associated with a significantly lower chance of poor outcome at both 2-weeks and 6-months, as well as the development of delayed cerebral ischemia. As opioids were indicated primarily for analgosedation in mechanically ventilated patients with poor clinical status, their usage was associated with a significantly higher chance of poor outcome, delayed cerebral ischemia, and hydrocephalus.

CONCLUSION

Our results suggest that the prescription of metamizole may be associated with better outcomes and a lower chance of delayed cerebral ischemia development in patients after subarachnoid hemorrhage. Considering the retrospective nature of our study and the limited worldwide availability of metamizole due to its prohibition in some countries, our results do not demonstrate a clear benefit but rather justify the need for subsequent prospective studies.

High Plasma D-Dimer Levels Correlate with Ictal Infarction and Poor Outcomes in Spontaneous Subarachnoid Hemorrhage

BACKGROUND

Early brain injury is the leading cause of poor outcomes in spontaneous subarachnoid hemorrhage (sSAH). Plasma D-dimer levels and acute cerebral ischemia have been highlighted as relevant findings in early brain injury; however, their correlation has not been substantially investigated.

METHODS

This retrospective, single-center cohort study was conducted at a tertiary emergency medical center from January 2004 to June 2022. Consecutive patients with sSAH who presented within 12 hours of ictus and underwent magnetic resonance imaging within 3 days were included. We assessed the correlation of plasma D-dimer levels with acute ischemic lesions detected on the diffusion-weighted imageing and the clinical characteristics.

RESULTS

Among 402 eligible patients (mean age, 63.5 years; 62.7% women; median time from onset to arrival, 45.5 minutes), 140 (34.8%) had acute ischemic lesions. Higher plasma D-dimer levels linearly correlated with worse neurological grades, more severe SAH on initial computed tomography, acute ischemic lesions, and poor outcomes, except for patients with neurogenic stunned myocardium. In the multivariate analysis, acute ischemic lesions were significantly associated with worse neurological grades, higher plasma D-dimer levels, bilateral loss of light reaction, and advanced age. The receiver operating characteristic curve analysis showed D-dimer levels as excellent predictors for acute ischemic lesions (area under the curve, 0.897; cut-off value, 5.7 μg/mL; P<0.0001) and unfavorable outcomes (area under the curve, 0.786; cut-off value, 4.0 μg/mL; P<0.0001).

CONCLUSIONS

High plasma D-dimer levels correlated with the appearance of acute ischemic lesions on diffusion-weighted imaging and were dose-dependently associated with worse neurological grades, more severe hemorrhage, and worse outcomes.

Metabolome and transcriptome integration reveals cerebral cortical metabolic profiles in rats with subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a severe subtype of hemorrhagic stroke. The molecular mechanisms of its secondary brain damage remain obscure. To investigate the alterations in gene and metabolite levels following SAH, we construct the transcriptome and metabolome profiles of the rat cerebral cortex post-SAH using whole transcriptome sequencing and untargeted metabolomics assays. Transcriptomic analysis indicated that there were 982 differentially expressed genes (DEGs) and 540 differentially expressed metabolites (DEMs) between the sham group and SAH 1d, and 292 DEGs and 254 DEMs between SAH 1d and SAH 7d. Most notably, DEGs were predominantly involved in the activation of immune and inflammatory pathways, particularly the Complement and coagulation cascades, TNF signaling pathway, and NOD-like receptor signaling pathway. Metabolic analysis revealed that the metabolic pathways of Arginine and proline, Arachidonic acid, Folate biosynthesis, Pyrimidine, and Cysteine and methionine were remarkably affected after SAH. Metabolites of the above pathways are closely associated not only with immune inflammation but also with oxidative stress, endothelial cell damage, and blood-brain barrier disruption. This study provides new insights into the underlying pathologic mechanisms of secondary brain injury after SAH and further characterization of these aberrant signals could enable their application as potential therapeutic targets for SAH.

Beyond nimodipine: advanced neuroprotection strategies for aneurysmal subarachnoid hemorrhage vasospasm and delayed cerebral ischemia

The clinical management of aneurysmal subarachnoid hemorrhage (SAH)-associated vasospasm remains a challenge in neurosurgical practice, with its prevention and treatment having a major impact on neurological outcome. While considered a mainstay, nimodipine is burdened by some non-negligible limitations that make it still a suboptimal candidate of pharmacotherapy for SAH. This narrative review aims to provide an update on the pharmacodynamics, pharmacokinetics, overall evidence, and strength of recommendation of nimodipine alternative drugs for aneurysmal SAH-associated vasospasm and delayed cerebral ischemia. A PRISMA literature search was performed in the PubMed/Medline, Web of Science, ClinicalTrials.gov, and PubChem databases using a combination of the MeSH terms "medical therapy," "management," "cerebral vasospasm," "subarachnoid hemorrhage," and "delayed cerebral ischemia." Collected articles were reviewed for typology and relevance prior to final inclusion. A total of 346 articles were initially collected. The identification, screening, eligibility, and inclusion process resulted in the selection of 59 studies. Nicardipine and cilostazol, which have longer half-lives than nimodipine, had robust evidence of efficacy and safety. Eicosapentaenoic acid, dapsone and clazosentan showed a good balance between effectiveness and favorable pharmacokinetics. Combinations between different drug classes have been studied to a very limited extent. Nicardipine, cilostazol, Rho-kinase inhibitors, and clazosentan proved their better pharmacokinetic profiles compared with nimodipine without prejudice with effective and safe neuroprotective role. However, the number of trials conducted is significantly lower than for nimodipine. Aneurysmal SAH-associated vasospasm remains an area of ongoing preclinical and clinical research where the search for new drugs or associations is critical.

Predicting outcome after aneurysmal subarachnoid hemorrhage by exploitation of signal complexity: a prospective two-center cohort study

BACKGROUND

Signal complexity (i.e. entropy) describes the level of order within a system. Low physiological signal complexity predicts unfavorable outcome in a variety of diseases and is assumed to reflect increased rigidity of the cardio/cerebrovascular system leading to (or reflecting) autoregulation failure. Aneurysmal subarachnoid hemorrhage (aSAH) is followed by a cascade of complex systemic and cerebral sequelae. In aSAH, the value of entropy has not been established yet.

METHODS

aSAH patients from 2 prospective cohorts (Zurich-derivation cohort, Aachen-validation cohort) were included. Multiscale Entropy (MSE) was estimated for arterial blood pressure, intracranial pressure, heart rate, and their derivatives, and compared to dichotomized (1-4 vs. 5-8) or ordinal outcome (GOSE-extended Glasgow Outcome Scale) at 12 months using uni- and multivariable (adjusted for age, World Federation of Neurological Surgeons grade, modified Fisher (mFisher) grade, delayed cerebral infarction), and ordinal methods (proportional odds logistic regression/sliding dichotomy). The multivariable logistic regression models were validated internally using bootstrapping and externally by assessing the calibration and discrimination.

RESULTS

A total of 330 (derivation: 241, validation: 89) aSAH patients were analyzed. Decreasing MSE was associated with a higher likelihood of unfavorable outcome independent of covariates and analysis method. The multivariable adjusted logistic regression models were well calibrated and only showed a slight decrease in discrimination when assessed in the validation cohort. The ordinal analysis revealed its effect to be linear. MSE remained valid when adjusting the outcome definition against the initial severity.

CONCLUSIONS

MSE metrics and thereby complexity of physiological signals are independent, internally and externally valid predictors of 12-month outcome. Incorporating high-frequency physiological data as part of clinical outcome prediction may enable precise, individualized outcome prediction. The results of this study warrant further investigation into the cause of the resulting complexity as well as its association to important and potentially preventable complications including vasospasm and delayed cerebral ischemia.

Baseline and average platelet count can predict the outcome of patients with aneurysmal subarachnoid hemorrhage

Background

Baseline values and the change of platelet count (PLT) during disease were reported to be associated with prognosis of patients with cancer and intensive care treatment. We aimed to evaluate the association between PLT with the course and prognosis of aneurysmal subarachnoid hemorrhage (SAH).

Methods

Admission (AdmPLT) and the 14-days mean PLT (MeanPLT) values of 763 SAH patients treated between 01/2005 and 06/2016 were recorded and, for further analysis, divided into four categories: <150, 150-260, 261-400 and > 400 × 109/L. Primary endpoints were cerebral infarcts in follow-up computed tomography scans, in-hospital mortality and unfavorable outcome at 6-months follow-up defined as modified Rankin scale>3. Adverse events during SAH were assessed as secondary endpoints.

Results

Higher PLT values were independently associated with lower risk of cerebral infarction (MeanPLT: aOR = 0.65 per-PLT-category-increase, p = 0.001), in-hospital mortality (AdmPLT: aOR = 0.64, p = 0.017; MeanPLT: aOR = 0.23, p < 0.0001) and unfavorable outcome (AdmPLT: aOR = 0.70, p = 0.031; MeanPLT: aOR = 0.35, p < 0.0001). Moreover, individuals with poorer outcome were less prone to PLT increase during SAH (mean values: -+20.3 vs + 30.5 × 109/L for cerebral infarction; +9.3 vs + 32.8 × 109/L for in-hospital mortality; +14.4 vs + 31.1 × 109/L for unfavorable outcome). The following adverse events during SAH were related to AdmPLT and/or MeanPLT: non-aneurysm related secondary rebleeding, intracranial hypertension requiring conservative treatment or decompressive craniectomy, sepsis and acute kidney failure.

Conclusion

Low PLT at admission and their less prominent increase during SAH were strongly linked with poor outcome of SAH. Further analysis is required to clarify the background of this association and potential therapeutic implications.

Increased blood coagulation is associated with poor neurological outcome in aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Patients with aneurysmal subarachnoid hemorrhage (aSAH) have demonstrated increased blood coagulation which is thought to contribute to delayed cerebral ischemia (DCI) and to a worse outcome. Therefore, we sought to determine whether this increased blood coagulation, detectable with rotational thromboelastometry (ROTEM), was associated with DCI and neurological outcome.

METHODS

We conducted a prospective observational study of 60 consecutive adult aSAH patients. ROTEM's EXTEM and FIBTEM assays and D-dimer were analyzed at admission and post-bleed days (PBDs) 2-3, 4-5, 7-8, and 11-12. ROTEM's clot formation time (CFT) represents the stabilization of the clot, and the maximum clot firmness (MCF) the maximum clot strength. Glasgow Outcome Scale extended (GOSe) at three months determined the neurological outcome.

RESULTS

DCI incidence was 41.7%. EXTEM-CFT was significantly shorter in patients with unfavorable neurological outcome (GOSe 1-4) on PBDs 4-5 and 7-8, p < 0.05, respectively. FIBTEM-MCF was significantly higher in patients with unfavorable neurological outcomes on PBD 4-5 (p < 0.05), PBD 7-8 (p < 0.05), and PBD 11-12 (p < 0.05). EXTEM-CFT decreased, and FIBTEM-MCF rose during the study period in all patients. Patients with unfavorable neurological outcome had a higher D-dimer at all studied time points, p < 0.05. No difference was found in the ROTEM parameters or D-dimer when assessing patients with and without DCI.

CONCLUSIONS

Patients were in a state of increased blood coagulation after aSAH, with those with unfavorable neurological outcome being more coagulable than those with favorable outcome. However, increased blood coagulation was not associated with DCI.

CLINICALTRIALS

gov, NCT03985176.

Poor Accuracy of Manually Derived Head Computed Tomography Parameters in Predicting Intracranial Hypertension After Nontraumatic Intracranial Hemorrhage

BACKGROUND

The utility of head computed tomography (CT) in predicting elevated intracranial pressure (ICP) is known to be limited in traumatic brain injury; however, few data exist in patients with spontaneous intracranial hemorrhage.

METHODS

We conducted a retrospective review of prospectively collected data in patients with nontraumatic intracranial hemorrhage (subarachnoid hemorrhage [SAH] or intraparenchymal hemorrhage [IPH]) who underwent external ventricular drain (EVD) placement. Head CT scans performed immediately prior to EVD placement were quantitatively reviewed for features suggestive of elevated ICP, including temporal horn diameter, bicaudate index, basal cistern effacement, midline shift, and global cerebral edema. The modified Fisher score (mFS), intraventricular hemorrhage score, and IPH volume were also measured, as applicable. We calculated the accuracy, positive predictive value (PPV), and negative predictive value (NPV) of these radiographic features for the coprimary outcomes of elevated ICP (> 20 mm Hg) at the time of EVD placement and at any time during the hospital stay. Multivariable backward stepwise logistic regression analysis was performed to identify significant radiographic factors associated with elevated ICP.

RESULTS

Of 608 patients with intracranial hemorrhages enrolled during the study time frame, 243 (40%) received an EVD and 165 (n = 107 SAH, n = 58 IPH) had a preplacement head CT scan available for rating. Elevated opening pressure and elevated ICP during hospitalization were recorded in 48 of 152 (29%) and 103 of 165 (62%), respectively. The presence of ≥ 1 radiographic feature had only 32% accuracy for identifying elevated opening pressure (PPV 30%, NPV 58%, area under the curve [AUC] 0.537, 95% asymptotic confidence interval [CI] 0.436-0.637, P = 0.466) and 59% accuracy for predicting elevated ICP during hospitalization (PPV 63%, NPV 40%, AUC 0.514, 95% asymptotic CI 0.391-0.638, P = 0.820). There was no significant association between the number of radiographic features and ICP elevation. Head CT scans without any features suggestive of elevated ICP occurred in 25 of 165 (15%) patients. However, 10 of 25 (40%) of these patients had elevated opening pressure, and 15 of 25 (60%) had elevated ICP during their hospital stay. In multivariable models, mFS (adjusted odds ratio [aOR] 1.36, 95% CI 1.10-1.68) and global cerebral edema (aOR 2.93, 95% CI 1.27-6.75) were significantly associated with elevated ICP; however, their accuracies were only 69% and 60%, respectively. All other individual radiographic features had accuracies between 38 and 58% for identifying intracranial hypertension.

CONCLUSIONS

More than 50% of patients with spontaneous intracranial hemorrhage without radiographic features suggestive of elevated ICP actually had ICP > 20 mm Hg during EVD placement or their hospital stay. Morphological head CT findings were only 32% and 59% accurate in identifying elevated opening pressure and ICP elevation during hospitalization, respectively.

Predictive nomogram models for unfavorable prognosis after aneurysmal subarachnoid hemorrhage: Analysis from a prospective, observational cohort in China

AIM

The aim of the study was to identify predictors for 3-month poor functional outcome or death after aSAH and develop precise and easy-to-use nomogram models.

METHODS

The study was performed at the department of neurology emergency in Beijing Tiantan Hospital. A total of 310 aSAH patients were enrolled between October 2020 and September 2021 as a derivation cohort, while a total of 208 patients were admitted from October 2021 to March 2022 as an external validation cohort. Clinical outcomes included poor functional outcome defined as modified Rankin Scale score (mRS) of 4-6 or all-cause death at 3 months. Least absolute shrinkage and selection operator (LASSO) analysis, as well as multivariable regression analysis, were applied to select independent variables associated with poor functional outcome or death and then to construct two nomogram models. Model performance were evaluated through discrimination, calibration, and clinical usefulness in both derivation cohort and external validation cohort.

RESULTS

The nomogram model to predict poor functional outcome included seven predictors: age, heart rate, Hunt-Hess grade on admission, lymphocyte, C-reactive protein (CRP), platelet, and direct bilirubin levels. It demonstrated high discrimination ability (AUC, 0.845; 95% CI: 0.787-0.903), satisfactory calibration curve, and good clinical usefulness. Similarly, the nomogram model combining age, neutrophil, lymphocyte, CRP, aspartate aminotransferase (AST) levels, and treatment methods to predict all-cause death also revealed excellent discrimination ability (AUC, 0.944; 95% CI: 0.910-0.979), satisfactory calibration curve, and clinical effectiveness. Internal validation showed the bias-corrected C-index for poor functional outcome and death was 0.827 and 0.927, respectively. When applied to the external validation dataset, both two nomogram models exhibited high discrimination capacity [poor functional outcome: AUC = 0.795 (0.716-0.873); death: AUC = 0.811 (0.707-0.915)], good calibration ability, and clinical usefulness.

CONCLUSIONS

Nomogram models constructed for predicting 3-month poor functional outcome or death after aSAH are precise and easily applicable, which can help physicians to identify patients at risk, guide decision-making, and provide new directions for future studies to explore the novel treatment targets.

Prognostic significance of fibrinogen and neutrophil/lymphocyte ratio score and D-dimer/Albumin ratio for prognosis in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

Recent research indicates that systemic inflammation significantly affects the overall prognosis of individuals with aneurysmal subarachnoid hemorrhage. To delve deeper into this issue, a retrospective study was undertaken. The study aimed to investigate the relationship between fibrinogen and neutrophil/lymphocyte ratio scores, D-dimer/Albumin ratios, and the Glasgow Outcome Scale at 6 months post-discharge for patients with aSAH.

METHODS

A retrospective analysis was conducted on 321 patients who experienced aneurysmal subarachnoid hemorrhage. These patients were monitored using the Glasgow Outcome Scale six months after being discharged from Huizhou Central People's Hospital. Patients with GOS scores between 1 and 3 were classified as having a poor prognosis, while those with scores ranging from 4 to 5 were considered to have a good prognosis. To create distinct sets, patients were randomly divided into both training and validation groups. The best cut-off value for the D-dimer/Albumin ratio was established through ROC curves, and the scores for fibrinogen and the neutrophil/lymphocyte ratio were calculated. Utilizing multivariate logistic regression analysis, independent risk factors linked to an unfavorable prognosis in aSAH patients were identified. A nomogram model was developed and validated based on these findings, providing an improved approach for evaluating the prognostic influence of risk factors. To gauge the model's predictive performance, several analytical tools such as ROC curves, calibration curves, and decision curve analysis were employed. This comprehensive approach ensured a thorough assessment of the prognostic prediction capabilities of the model.

RESULTS

Multivariate regression analysis revealed that Age (OR=3.87, 95%CI=1.54-9.73, p=0.004), Pneumonia (OR=3.54, 95%CI=1.41-8.86, p=0.007), WFNS (OR=3.24, 95%CI=1.23-8.54, p=0.017), DAR (OR=2.88, 95%CI=1.13-7.34, p=0.027), and F-NLR (OR=3.12, 95%CI=1.22-7.97, p=0.017) were identified as independent risk factors influencing the prognosis of patients with aSAH. Additionally, the area under the ROC curve was 0.866 (95%CI=0.805-0.927) for the training set and 0.924 (95%CI=0.849-0.999) for the validation set. The calibration curve analysis demonstrated a minor error of 0.02 for the training set and 0.051 for the validation set. Furthermore, both the training set and validation set displayed significant clinical benefits according to the DCA curves, underscoring the meaningful utility of the developed nomogram.

CONCLUSIONS

Fibrinogen and neutrophil/lymphocyte ratio scores, and the D-dimer/Albumin ratio emerged as significant independent risk factors for prognosticating the outcomes of patients with aSAH. Leveraging these factors, a robust nomogram model was meticulously developed, showcasing its impressive precision in prognostic predictions. These results underscore the promising clinical applicability of these biomarkers as effective prognostic indicators for individuals afflicted by aSAH.

Association between a four-parameter inflammatory index and all-cause mortality in critical ill patients with non-traumatic subarachnoid hemorrhage: a retrospective analysis of the MIMIC-IV database (2012-2019)

Background

Non-traumatic subarachnoid hemorrhage (SAH), primarily due to the rupture of intracranial aneurysms, contributes significantly to the global stroke population. A novel biomarker, pan-immune-inflammation value (PIV) or called the aggregate index of systemic inflammation (AISI), linked to progression-free survival and overall survival in non-small-cell lung cancer and mortality in Coronavirus Disease 2019 (COVID-19) patients, has surfaced recently. Its role in non-traumatic SAH patients, however, remains under-researched. This study aims to determine the relationship between PIV and all-cause mortality in non-traumatic SAH patients.

Methods

A retrospective analysis was conducted using data from the Medical Information Mart for Intensive Care (MIMIC-IV) database to examine the association between PIV and all-cause mortality in critically ill patients with non-traumatic SAH. PIV measurements were collected at Intensive Care Unit (ICU) admission, and several mortality measures were examined. To control for potential confounding effects, a 1:1 propensity score matching (PSM) method was applied. The optimal PIV cutoff value was identified as 1362.45 using X-tile software that is often used to calculate the optimal cut-off values in survival analysis and continuous data of medical or epidemiological research. The relationship between PIV and short- and long-term all-cause mortality was analyzed using a multivariate Cox proportional hazard regression model and Kaplan-Meier (K-M) survival curve analysis. Interaction and subgroup analyses were also carried out.

Results

The study included 774 non-traumatic SAH patients. After PSM, 241 pairs of score-matched patients were generated. The Cox proportional hazard model, adjusted for potential confounders, found a high PIV (≥ 1362.45) independently associated with 90-day all-cause mortality both pre- (hazard ratio [HR]: 1.67; 95% confidence intervals (CI): 1.05-2.65; P = 0.030) and post-PSM (HR: 1.58; 95% CI: 1.14-2.67; P = 0.042). K-M survival curves revealed lower 90-day survival rates in patients with PIV ≥ 1362.45 before (31.1% vs. 16.1%%, P < 0.001) and after PSM (68.9% vs. 80.9%, P < 0.001). Similarly, elevated PIV were associated with increased risk of ICU (pre-PSM: HR: 2.10; 95% CI: 1.12-3.95; P = 0.02; post-PSM: HR: 2.33; 95% CI: 1.11-4.91; P = 0.016), in-hospital (pre-PSM: HR: 1.91; 95% CI: 1.12-3.26; P = 0.018; post-PSM: 2.06; 95% CI: 1.10-3.84; P = 0.034), 30-day (pre-PSM: HR: 1.69; 95% CI: 1.01-2.82; P = 0.045; post-PSM: 1.66; 95% CI: 1.11-2.97; P = 0.047), and 1-year (pre-PSM: HR: 1.58; 95% CI: 1.04-2.40; P = 0.032; post-PSM: 1.56; 95% CI: 1.10-2.53; P = 0.044) all-cause mortality. The K-M survival curves confirmed lower survival rates in patients with higher PIV both pre- and post PSM for ICU (pre-PSM: 18.3% vs. 8.4%, P < 0.001; post-PSM:81.7 vs. 91.3%, P < 0.001), in-hospital (pre-PSM: 25.3% vs. 12.8%, P < 0.001; post-PSM: 75.1 vs. 88.0%, P < 0.001), 30-day (pre-PSM: 24.9% vs. 11.4%, P < 0.001; post-PSM:74.7 vs. 86.3%, P < 0.001), and 1-year (pre-PSM: 36.9% vs. 20.8%, P < 0.001; P = 0.02; post-PSM: 63.1 vs. 75.1%, P < 0.001) all-cause mortality. Stratified analyses indicated that the relationship between PIV and all-cause mortality varied across different subgroups.

Conclusion

In critically ill patients suffering from non-traumatic SAH, an elevated PIV upon admission correlated with a rise in all-cause mortality at various stages, including ICU, in-hospital, the 30-day, 90-day, and 1-year mortality, solidifying its position as an independent mortality risk determinant. This study represents an attempt to bridge the current knowledge gap and to provide a more nuanced understanding of the role of inflammation-based biomarkers in non-traumatic SAH. Nevertheless, to endorse the predictive value of PIV for prognosticating outcomes in non-traumatic SAH patients, additional prospective case-control studies are deemed necessary.

Blood inflammatory biomarkers predict in-hospital pneumonia after endovascular treatment of aneurysm in patients with aneurysmal subarachoid hemorrhage

The systemic inflammatory response index (SIRI) is a well-known marker of systemic inflammation reflecting the body's inflammatory/immune state. The study aimed to evaluate the relationship between the SIRI on admission and aneurysmal subarachnoid hemorrhage (aSAH)-associated pneumonia and compare with other currently used bio-markers. We reviewed 562 successive patients with aneurysmal SAH who underwent endovascular treatment between January 2019 and September 2021. ASAH-associated pneumonia was diagnosed using the modified Centers for Disease Control and Prevention criteria. The SIRI on admission was calculated as monocyte count × neutrophil count / lymphocyte count. Multiple logistic regression models were used for data analysis. A total of 158 (28.11%) patients developed aSAH-associated pneumonia. Using the Multiple logistic regression analysis, a notable dose-response association was found between the elevated SIRI (fourth quartile) and aSAH-associated pneumonia (adjusted odds ratio = 6.759; 95% confidence interval [CI], 3.280-13.930; p < 0.001 [p for trend < 0.001]). The SIRI (0.701, 95% CI: 0.653-0.749) presented a higher area under the curve (AUC) than systemic immune- inflammation index (SII) (0.669, 95% CI: 0.620-0.718) (p = 0.089); neutrophil-to-lymphocyte ratio (NLR) (0.665, 95% CI: 0.616-0.714) (p = 0.035) and platelet-lymphocyte ratio (PLR) (0.587, 95% CI: 0.534-0.641) (p < 0.001). A higher SIRI on admission was associated with aSAH-associated pneumonia, which may guide further clinical trials of prophylactic antibiotic therapy.

Haptoglobin Treatment for Aneurysmal Subarachnoid Hemorrhage: Review and Expert Consensus on Clinical Translation

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating form of stroke frequently affecting young to middle-aged adults, with an unmet need to improve outcome. This special report focusses on the development of intrathecal haptoglobin supplementation as a treatment by reviewing current knowledge and progress, arriving at a Delphi-based global consensus regarding the pathophysiological role of extracellular hemoglobin and research priorities for clinical translation of hemoglobin-scavenging therapeutics. After aneurysmal subarachnoid hemorrhage, erythrocyte lysis generates cell-free hemoglobin in the cerebrospinal fluid, which is a strong determinant of secondary brain injury and long-term clinical outcome. Haptoglobin is the body's first-line defense against cell-free hemoglobin by binding it irreversibly, preventing translocation of hemoglobin into the brain parenchyma and nitric oxide-sensitive functional compartments of cerebral arteries. In mouse and sheep models, intraventricular administration of haptoglobin reversed hemoglobin-induced clinical, histological, and biochemical features of human aneurysmal subarachnoid hemorrhage. Clinical translation of this strategy imposes unique challenges set by the novel mode of action and the anticipated need for intrathecal drug administration, necessitating early input from stakeholders. Practising clinicians (n=72) and scientific experts (n=28) from 5 continents participated in the Delphi study. Inflammation, microvascular spasm, initial intracranial pressure increase, and disruption of nitric oxide signaling were deemed the most important pathophysiological pathways determining outcome. Cell-free hemoglobin was thought to play an important role mostly in pathways related to iron toxicity, oxidative stress, nitric oxide, and inflammation. While useful, there was consensus that further preclinical work was not a priority, with most believing the field was ready for an early phase trial. The highest research priorities were related to confirming haptoglobin's anticipated safety, individualized versus standard dosing, timing of treatment, pharmacokinetics, pharmacodynamics, and outcome measure selection. These results highlight the need for early phase trials of intracranial haptoglobin for aneurysmal subarachnoid hemorrhage, and the value of early input from clinical disciplines on a global scale during the early stages of clinical translation.

A Systematic Review of Viscoelastic Testing in Patients with Subarachnoid Hemorrhage

OBJECTIVE

Bleeding and thromboembolic complications frequently occur after subarachnoid hemorrhage (SAH) and substantially contribute to poor outcome. Viscoelastic testing could be used for detection of coagulopathies after SAH. This review summarizes literature on the usefulness of viscoelastic testing to detect coagulopathy in patients with SAH and explores whether viscoelastic parameters are associated with SAH-related complications and clinical outcome.

METHODS

PubMed, Embase, and Google Scholar were systematically searched on August 18, 2022. Two authors independently selected studies that reported viscoelastic testing in patients with SAH and assessed the quality of studies using the Newcastle-Ottawa Scale or a previously reported framework for quality assessment. Data were meta-analyzed if methodologically possible.

RESULTS

The search yielded 19 studies (1160 patients with SAH). Pooling of data including all relevant studies was not possible for any of the outcome measurements because of methodological differences. Thirteen of 19 studies evaluated the association of coagulation profiles and SAH, of which 11 studies showed a hypercoagulable profile. Rebleeding was associated with platelet dysfunction, deep venous thrombosis was associated with faster clot initiation, and both delayed cerebral ischemia and poor outcome were associated with increased clot strength.

CONCLUSIONS

This explorative review shows that patients with SAH frequently have a hypercoagulable profile. Thromboelastography (TEG) and rotational thromboelastometry (ROTEM) parameters are associated with rebleeding, delayed cerebral ischemia, deep venous thrombosis, and poor clinical outcome after SAH; however, more research on the subject is needed. Future studies should focus on determining the optimal time frame and cutoff values for TEG or ROTEM to predict these complications.

Elevated HMGB1 and sRAGE levels in cerebrospinal fluid of aneurysmal subarachnoid hemorrhage patients

BACKGROUND

Neuroinflammation after aneurysmal subarachnoid hemorrhage (aSAH) leads to poor outcome of patients. High mobility group box 1 (HMGB1) contributes to inflammation through binding to receptors for advanced glycation end-products (RAGE) in various diseases. We aimed to determine the production of these two factors after aSAH and their relationship with clinical features.

METHODS

HMGB1 and soluble RAGE (sRAGE) levels in cerebrospinal fluid (CSF) of aSAH patients and controls were measured, and their temporal courses were observed. The correlation between early concentrations (days 1-3) and clinical symptoms assessed by disease severity scores, neuroinflammation estimated by CSF IL-6 levels, as well as prognosis evidenced by delayed cerebral ischemia (DCI) and 6-month adverse outcome was investigated. Finally, combined analysis of early levels for predicting prognosis was confirmed.

RESULTS

CSF HMGB1 and sRAGE levels were higher in aSAH patients than in controls (P < 0.05), and the levels decreased from higher early to lower over time. Their early concentrations were positively associated with disease severity scores, IL-6 levels, DCI and 6-month poor outcome (P < 0.05). HMGB1 ≥ 6045.5 pg/ml (OR = 14.291, P = 0.046) and sRAGE ≥ 572.0 pg/ml (OR = 13.988, P = 0.043) emerged as independent predictors for DCI, while HMGB1 ≥ 5163.2 pg/ml (OR = 7.483, P = 0.043) and sRAGE ≥ 537.3 pg/ml (OR = 12.653, P = 0.042) were predictors for 6-month poor outcome. Combined analysis of them improved predictive values of adverse prognosis.

CONCLUSION

CSF HMGB1 and sRAGE levels of aSAH patients were increased early and then varied dynamically, which might act as potential biomarkers for poor outcome, especially when co-analyzed.

A Pooled Analysis of Preoperative Inflammatory Biomarkers to Predict 90-Day Outcomes in Patients with an Aneurysmal Subarachnoid Hemorrhage: A Single-Center Retrospective Study

An inflammatory response after an aneurysmal subarachnoid hemorrhage (aSAH) has always been in the spotlight. However, few studies have compared the prognostic impact of inflammatory biomarkers. Moreover, why these inflammatory biomarkers contribute to a poor prognosis is also unclear. We retrospectively reviewed aSAH patients admitted to our institution between January 2015 and December 2020. The 90-day unfavorable functional outcome was defined as a modified Rankin scale (mRS) of ≥ 3. Independent inflammatory biomarker-related risk factors associated with 90-day unfavorable outcomes were derived from a forward stepwise multivariate analysis. Receiver operating characteristic curve analysis was conducted to identify the best cut-off value of inflammatory biomarkers. Then, patients were divided into two groups according to each biomarker's cut-off value. To eliminate the imbalances in baseline characteristics, propensity score matching (PSM) was carried out to assess the impact of each biomarker on in-hospital complications. A total of 543 patients were enrolled in this study and 96 (17.7%) patients had unfavorable 90-day outcomes. A multivariate analysis showed that the white blood cell (WBC) count, the systemic inflammation response index, the neutrophil count, the neutrophil-to-albumin ratio, the monocyte count, and the monocyte-to-lymphocyte ratio were independently associated with 90-day unfavorable outcomes. The WBC count showed the best predictive ability (area under the curve (AUC) = 0.710, 95% CI = 0.652-0.769, p < 0.001). After PSM, almost all abnormal levels of inflammatory biomarkers were associated with a higher incidence of pneumonia during hospitalization. The WBC count had the strongest association with poor outcomes. Similar to nearly all other inflammatory biomarkers, the cause of poor prognosis may be the higher incidence of in-hospital pneumonia.

Pathophysiology of Early Brain Injury and Its Association with Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage: A Review of Current Literature

Background: Delayed cerebral ischemia (DCI) is a common and serious complication of aneurysmal subarachnoid hemorrhage (aSAH). Though many clinical trials have looked at therapies for DCI and vasospasm in aSAH, along with reducing rebleeding risks, none have led to improving outcomes in this patient population. We present an up-to-date review of the pathophysiology of DCI and its association with early brain injury (EBI). Recent Findings: Recent studies have demonstrated that EBI, as opposed to delayed brain injury, is the main contributor to downstream pathophysiological mechanisms that play a role in the development of DCI. New predictive models, including advanced monitoring and neuroimaging techniques, can help detect EBI and improve the clinical management of aSAH patients. Summary: EBI, the severity of subarachnoid hemorrhage, and physiological/imaging markers can serve as indicators for potential early therapeutics in aSAH. The microcellular milieu and hemodynamic pathomechanisms should remain a focus of researchers and clinicians. With the advancement in understanding the pathophysiology of DCI, we are hopeful that we will make strides toward better outcomes for this unique patient population.

Utility of serum amyloid A as a potential prognostic biomarker of aneurysmal subarachnoid hemorrhage

Objectives

Inflammation plays a vital role in the aneurysmal subarachnoid hemorrhage (aSAH), while serum amyloid A (SAA) has been identified as an inflammatory biomarker. The present study aimed to elucidate the relationship between SAA concentrations and prognosis in aSAH.

Methods

From prospective analyses of patients admitted to our department between March 2016 and August 2022, aSAH patients with complete medical records were evaluated. Meanwhile, the healthy control group consisted of the age and sex matched individuals who came to our hospital for healthy examination between March 2018 and August 2022. SAA level was measured by enzyme-linked immunosorbent assay kit (Invitrogen Corp). The Glasgow Outcome Scale (GOS) was used to classify patients into good (GOS score of 4 or 5) and poor (GOS score of 1, 2, or 3) outcome.

Results

456 patients were enrolled in the study, thereinto, 200 (43.86%) patients had a poor prognosis at the 3-months follow-up. Indeed, the SAA of poor outcome group were significantly increased compared to good outcome group and healthy control group [36.44 (32.23-41.00) vs. 28.99 (14.67-34.12) and 5.64 (3.43-7.45), P < 0.001]. In multivariate analyses, SAA served for independently predicting the poor outcome after aICH at 3 months [OR:1.129 (95% CI, 1.081-1.177), P < 0.001]. After adjusting the underlying confounding factors, the odds ratio (OR) of depression after aSAH was 2.247 (95% CI: 1.095-4.604, P = 0.021) for the highest tertile of SAA relative to the lowest tertile. With an AUC of 0.807 (95% CI, 0.623-0.747), SAA demonstrated an obviously better discriminatory ability relative to CRP, WBC, and IL-6. SAA as an indicator for predicting poor outcome after aSAH had an optimal cut-off value of 30.28, and the sensitivity and specificity were 61.9 and 78.7%, respectively.

Conclusions

Elevated level of SAA was associated with poor outcome at 3 months, suggesting that SAA might be a useful inflammatory markers to predict prognosis after aSAH.

The clinical significance of peripheral blood cell ratios in patients with intracranial aneurysm

Background and objective

Inflammation is an important factor in the development of aneurysm, and has been identified as a key characteristic predictive of rupture of intracranial aneurysm (IA). However, the role of inflammatory peripheral blood cell ratios in patients with IA has not been well delineated.

Methods

A total of 1,209 patients, including 1,001 with unruptured IA and 208 with ruptured IA, were enrolled in this study. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), platelet-to-neutrophil ratio (PNR), and platelet-to-white-blood-cell ratio (PWR) were compared between ruptured and unruptured IA.

Results

Compared with the ruptured IA group, the unruptured IA group had higher PNR {median, 65.96 [interquartile range (IQR) 48.95-85.05] vs. 37.78 (IQR, 23.17-54.05); p < 0.001} and PWR [median, 36.89 (IQR 29.38-44.56) vs. 22.39 (IQR, 16.72-29.29); p < 0.001]. In multivariate analysis, PNR and PWR were independently associated with ruptured IA (p = 0.001 and p < 0.001, respectively). Unruptured IA subgroup analyses according to the PHASES scores showed that a higher PHASES score was associated with significantly higher NLR and erythrocyte sedimentation rate (p < 0.001 and p = 0.025) and lower PNR and PWR (p < 0.001 and p = 0.007).

Conclusions

We demonstrated that lower PNR and PWR levels are associated with ruptured IA and a higher PHASES score. Unlike many other inflammatory markers and bioassays, peripheral blood cell ratios are inexpensive and readily available biomarkers that may be useful for risk stratification in patients with cerebral aneurysm. However, a long-term prospective study is needed to clarify this matter.

A Simple Label-Free Aptamer-Based Electrochemical Biosensor for the Sensitive Detection of C-Reactive Proteins

The level of C-reactive protein (CRP) in the human body is closely associated with cardiovascular diseases and inflammation. In this study, a label-free functionalized aptamer sensor was attached to an electrode trimmed with in-gold nanoparticles and carboxylated graphene oxide (AuNPs/GO-COOH) to achieve sensitive measurements relative to CRP. Gold nanoparticles were selected for this study due to super stability, remarkably high electrical conductivity, and biocompatibility. In addition, carboxylated graphene oxide was utilized to promote the anchorage of inducer molecules and to increase detection accuracies. The sensing signal was recorded using differential pulse voltammetry (DPV), and it produced a conspicuous peak current obtained at approximately -0.4 V. Furthermore, the adapted sensor manifested a broad linear span from 0.001 ng/mL to 100 ng/mL. The results also demonstrated that this aptamer sensor had superior stability, specificity, and reproducibility. This aptamer-based electrochemical sensor has enormous potential in complex application situations with interfering substances.

Viscoelastic Testing in the Clinical Management of Subarachnoid Hemorrhage and Intracerebral Hemorrhage

Subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH) are both debilitating and life-threatening incidents calling for immediate action and treatment. This review focuses on the applicability of viscoelastic testing (rotational thromboelastometry or thromboelastography [TEG]) in the management of SAH and ICH. A systematic literature search was performed in PubMed and EMBASE. Studies including patients with SAH or ICH, in which viscoelastic testing was performed, were identified. In total, 24 studies were included for analysis, and further subdivided into studies on SAH patients investigated prior to stenting or coiling (n = 12), ICH patients (n = 8) and studies testing patients undergoing stenting or coiling, or ischemic stroke patients undergoing thrombolysis or thrombectomy and developing ICH as a complication (n = 5). SAH patients had increased clot firmness, and this was associated with a higher degree of early brain injury and higher Hunt-Hess score. SAH patients with delayed cerebral ischemia had higher clot firmness than patients not developing delayed cerebral ischemia. ICH patients showed accelerated clot formation and increased clot firmness in comparison to healthy controls. Patients with hematoma expansion had longer clot initiation and lower platelet aggregation than patients with no hematoma expansion. During stent procedures for SAH, adjustment of antiplatelet therapy according to TEG platelet mapping did not change prevalence of major bleeding, thromboembolic events, or functional outcome. Viscoelastic testing prior to thrombolysis showed conflicting results in predicting ICH as complication. In conclusion, viscoelastic testing suggests hypercoagulation following SAH and ICH. Further investigation of the predictive value of increased clot firmness in SAH seems relevant. In ICH, the prediction of hematoma expansion and ICH as a complication to thrombolysis might be clinically relevant.

Spontaneous subarachnoid haemorrhage

Subarachnoid haemorrhage (SAH) is the third most common subtype of stroke. Incidence has decreased over past decades, possibly in part related to lifestyle changes such as smoking cessation and management of hypertension. Approximately a quarter of patients with SAH die before hospital admission; overall outcomes are improved in those admitted to hospital, but with elevated risk of long-term neuropsychiatric sequelae such as depression. The disease continues to have a major public health impact as the mean age of onset is in the mid-fifties, leading to many years of reduced quality of life. The clinical presentation varies, but severe, sudden onset of headache is the most common symptom, variably associated with meningismus, transient or prolonged unconsciousness, and focal neurological deficits including cranial nerve palsies and paresis. Diagnosis is made by CT scan of the head possibly followed by lumbar puncture. Aneurysms are commonly the underlying vascular cause of spontaneous SAH and are diagnosed by angiography. Emergent therapeutic interventions are focused on decreasing the risk of rebleeding (ie, preventing hypertension and correcting coagulopathies) and, most crucially, early aneurysm treatment using coil embolisation or clipping. Management of the disease is best delivered in specialised intensive care units and high-volume centres by a multidisciplinary team. Increasingly, early brain injury presenting as global cerebral oedema is recognised as a potential treatment target but, currently, disease management is largely focused on addressing secondary complications such as hydrocephalus, delayed cerebral ischaemia related to microvascular dysfunction and large vessel vasospasm, and medical complications such as stunned myocardium and hospital acquired infections.

Prognostic significance of combined score of fibrinogen and neutrophil-lymphocyte ratio for functional outcome in patients with aneurysmal subarachnoid hemorrhage

Objective

To explore the relationship between fibrinogen and neutrophil to lymphocyte ratio (F-NLR) score and functional outcomes after aneurysmal subarachnoid hemorrhage (aSAH).

Method

A retrospective study was conducted that involved all consecutive patients with aSAH admitted to our institution from March 2018 to October 2021. Factors, such as demographics, comorbidities, clinical characteristics, neuroradiological data, and laboratory parameters, were collected from institutional databases. All patients achieved neurological assessment using the modified Rankin Scale (mRS) score 3 months after discharge to clarify the functional outcomes. The results were classified as favorable (mRS score 0–2) and unfavorable (mRS score 3–6). Univariate and multivariable analyses were performed to identify the relevant factors between inflammatory markers and functional outcomes after aSAH. Subsequently, a receiver operating characteristic (ROC) curve analysis was conducted to evaluate the predicting performance of variables. A propensity score match (PSM) was performed to correct imbalances in patients' baseline characteristics.

Results

Finally, 256 patients with aSAH were included in the study cohort. A total of 94 (36.7%) patients had an unfavorable outcome. F-NLR scores were 0 [interquartile range (IQR) 0–1] and 1 (IQR 1–2) in patients with favorable and unfavorable outcomes, respectively (p < 0.001). After adjustment, the F-NLR score on admission remained significantly associated with unfavorable outcomes in patients with aSAH. In the multivariable analysis, the F-NLR score was regarded as an independent risk factor of unfavorable outcomes [odds ratio (OR) 3.113, 95% CI 1.755–5.523, p < 0.001]. In ROC analysis, the optimal cutoff value of the F-NLR score was 0.5 points. Two cohorts (n = 86 in each group) obtained from PSM with low F-NLR scores (0 points) and high F-NLR scores (1–2 points) were used for analysis. A significantly higher unfavorable functional outcome rate was observed in patients with high F-NLR scores (33.7 vs. 9.3%, p < 0.001). The area under the curve (AUC) values of F-NLR scores before and after PSM were 0.767 and 0.712, respectively.

Conclusion

Fibrinogen and neutrophil to lymphocyte ratio score was an independent risk parameter associated with unfavorable functional outcomes at 3 months after aSAH. A higher F-NLR score predicts the occurrence of poor functional outcomes.

Antiplatelet therapy and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

OBJECTIVE

Delayed cerebral ischemia (DCI) is a potentially preventable cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). The authors performed a meta-analysis to assess the effect of antiplatelet therapy (APT) on DCI in patients with aSAH.

METHODS

A systematic review of the PubMed and MEDLINE databases was performed. Study inclusion criteria were 1) ≥ 5 aSAH patients; 2) direct comparison between aSAH management with APT and without APT; and 3) reporting of DCI, angiographic, or symptomatic vasospasm rates for patients treated with versus without APT. The primary efficacy outcome was DCI. The outcomes of the APT versus no-APT cohorts were compared. Bias was assessed using the Downs and Black checklist.

RESULTS

The overall cohort comprised 2039 patients from 15 studies. DCI occurred less commonly in the APT compared with the no-APT cohort (pooled = 15.9% vs 28.6%; OR 0.47, p < 0.01). Angiographic (pooled = 51.6% vs 68.7%; OR 0.46, p < 0.01) and symptomatic (pooled = 23.6% vs 37.7%; OR 0.51, p = 0.01) vasospasm rates were lower in the APT cohort. In-hospital mortality (pooled = 1.7% vs 4.1%; OR 0.53, p = 0.01) and functional dependence (pooled = 21.0% vs 35.7%; OR 0.53, p < 0.01) rates were also lower in the APT cohort. Bleeding event rates were comparable between the two cohorts. Subgroup analysis of cilostazol monotherapy compared with no APT demonstrated a lower DCI rate in the cilostazol cohort (pooled = 10.6% vs 28.1%; OR 0.31, p < 0.01). Subgroup analysis of surgically treated aneurysms demonstrated a lower DCI rate for the APT cohort (pooled = 18.4% vs 33.9%; OR 0.43, p = 0.02).

CONCLUSIONS

APT is associated with improved outcomes in aSAH without an increased risk of bleeding events, particularly in patients who underwent surgical aneurysm repair and those treated with cilostazol. Although study heterogeneity is the most significant limitation of the analysis, the findings suggest that APT is worth exploring in patients with aSAH, particularly in a randomized controlled trial setting.

Microclots in subarachnoid hemorrhage: an underestimated factor in delayed cerebral ischemia?

Subarachnoid hemorrhage has a poor prognosis due to the wide array of associated complications such as vasospasm, early brain injury, cortical spreading depression, oxidative stress, inflammation, and apoptosis. Each of these complications increases the risk of delayed cerebral ischemia (DCI), but recent research has suggested microclots play a substantial role in DCI incidence. This review will focus on the underlying inflammatory and coagulative mechanisms of microthrombosis while also outlining the current literature relating microclot burden to DCI. With a better understanding DCI pathophysiology as it relates to microthrombosis, more effective therapies can be developed in the future to improve clinical outcomes of SAH.

XGBoost Machine Learning Algorithm for Prediction of Outcome in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Patients suffered aneurysmal subarachnoid hemorrhage (aSAH) usually develop poor survival and functional outcome. Evaluating aSAH patients at high risk of poor outcome is necessary for clinicians to make suitable therapeutical strategy. This study is conducted to develop prognostic model using XGBoost (extreme gradient boosting) algorithm in aSAH.

METHODS

A total of 351 aSAH patients admitted to West China hospital were identified. Patients were divided into training set and test set with ratio of 7:3 to testify the predictive value of XGBoost based prognostic model. Additionally, logistic regression model was also constructed and compared with XGBoost based model. Area under the receiver operating characteristic curve (AUC), sensitivity and specificity were calculated to evaluate the value of XGBoost and logistic regression.

RESULTS

There were 74 (21.1%) non-survivors and 148 (42.1%) patients with unfavorable functional outcome. Non-survivors had older age (p=0.025), lower Glasgow coma scale (GCS) (p<0.001), higher World Federation of Neurosurgical Societies WFNS score (p<0.001), mFisher score (p<0.001). The incidence of intraventricular hemorrhage (IVH) (p=0.025) and delayed cerebral ischemia (DCI) (p<0.001) was higher in non-survivors than survivors. The AUC of XGBoost model for predicting mortality and unfavorable functional outcome were 0.950 and 0.958, which were higher than 0.767 and 0.829 of logistic regression model.

CONCLUSION

XGBoost based model is more precise than logistic regression model in predicting outcome of aSAH patients. Using XGBoost prognostic model is helpful for clinicians to identify high-risk aSAH patients and therefore strengthen medical care.

Predictive effects of admission white blood cell counts and hounsfield unit values on delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Neuroinflammatory response is deemed the primary pathogenesis of delayed cerebral ischemia (DCI) caused by aneurysmal subarachnoid hemorrhage (aSAH). Both white blood cell (WBC) count and Hounsfield Unit (HU) are gradually considered can reflect inflammation in DCI. This study aims to identify the relationship between WBC count and HU value and investigate the effects of both indicators in predicting DCI after aSAH.

METHODS

We enrolled 109 patients with aSAH admitted within 24 h of onset in our study. A multivariate logistic regression analysis was used to evaluate the admission WBC count, HU value, and combined WBC-HU associated with DCI. The receiver operating characteristic curve and area under the curve (AUC) were used to determine thresholds and detect the predictive ability of these predictors. These indicators were also compared with the established inflammation markers.

RESULTS

Thirty-six (33%) patients developed DCI. Both WBC count and HU value were strongly associated with the admission glucose level (ρ = .303, p = .001; ρ = .273, p = .004), World Federation of Neurosurgical Societies grade (ρ = .452, p < .001; ρ = .578; p < .001), Hunt-Hess grade (ρ = .450, p < .001; ρ = .510, p < .001), and modified Fisher scale score (ρ = .357, p < .001; ρ = .330, p < .001). After controlling these public variables, WBC count (ρ = .300, p = .002) positively correlated with HU value. An early elevated WBC (odds ratio [OR] 1.449, 95% confidence interval [CI]: 1.183-1.774, p < .001) count and HU value (OR 1.304, 95%CI: 1.149-1.479, p < .001) could independently predict the occurrence of DCI. However, only these patients with both WBC count and HU value exceeding the cut-off points (OR 36.89, 95%CI: 5.606-242.78, p < .001) were strongly correlated with DCI. Compared with a single WBC count (AUC 0.811, 95%CI: 0.729-0.892, p < .001) or HU value (AUC 0.869, 95%CI: 0.803-0.936, p < .001), the combined WBC-HU (AUC 0.898, 95%CI: 0.839-0.957, p < .001) demonstrated a better ability to predict the occurrence of DCI. Inspiringly, the prediction performance of these indicators outperformed the established inflammatory markers.

CONCLUSION

An early elevated WBC count and HU value could independently predict DCI occurrence between 4 and 30 days after aSAH. Furthermore, WBC count was positively correlated with HU value, and the combined WBC-HU demonstrated a superior prediction ability for DCI development compared with the individual indicator.

Clinical Treatment and Prognostic Analysis of Patients with Aneurysmal Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a serious disease caused by blood flow into the subarachnoid space due to rupture of blood vessels. All diseases that cause intracranial hemorrhage are the cause of subarachnoid hemorrhage. Among them, due to the particularity of intracranial blood vessels, intracranial blood vessels are more prone to aneurysms than other parts. Therefore, the incidence of aneurysmal subarachnoid hemorrhage (aSAH) is extremely high. The purpose of this article is to study the clinical treatment and prognosis analysis of aSAH patients. This article first summarizes the current status of SAH research at home and abroad and summarizes its potential value and significance. On this basis, an in-depth study of the clinical treatment of aSAH patients has been carried out. The physiological mechanism and clinical general differences of aSAH were studied and analyzed. This article systematically describes the application of CTP in the treatment and prognosis analysis of aSAH patients. Then, it will use a comparative analysis method, interdisciplinary method, and other research forms to carry out experimental research on the theme of this article. Research shows that rebleeding and blood sodium are the main factors for cerebral ischemia caused by aSAH.

ANGPT1 methylation and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage patients

Background:

Delayed cerebral ischemia (DCI) is a common secondary complication and an important cause of disability and mortality among patients who survive aneurysmal subarachnoid hemorrhage (aSAH). Knowledge on DCI pathogenesis, risk factors, and biomarkers are essential for early detection and improved prognosis. To investigate the role of DNA methylation in DCI risk, we conducted an epigenome-wide association study (EWAS) in 68 patients followed up to 1 year after the initial aneurysm rupture. Blood samples were collected within 48 h post hemorrhage and used for DNA methylation profiling at ~ 450k CpG sites. A separate cohort of 175 patients was sequenced for the top CpG sites from the discovery analysis for a replication of the EWAS findings.

Results:

EWAS did not identify any epigenome-wide significant CpGs. The top signal, cg18031596, was annotated to ANGPT1, a gene with critical functions in angiogenesis after vascular injury. Post hoc power calculations indicated a well-powered discovery analysis for cg18031596. Analysis of the replication cohort showed that four out of the five CpG sites sequenced at the ANGPT1 locus passed a Bonferroni-adjusted significance threshold. In a pooled analysis of the entire sample, three out of five yielded a significant p-value, and the top association signal (p-value = 0.004) was seen for a CpG that was not originally measured in the discovery EWAS. However, four ANGPT1 CpG sites had an opposite effect direction in the replication analysis compared to the discovery EWAS, marking a failure of replication. We carefully examined this observed flip in directions and propose several possible explanations in addition to that it was a random chance that ANGPT1 ranked at the top in the discovery EWAS.

Conclusions:

We failed to demonstrate a significant and consistent effect of ANGPT1 methylation in DCI risk in two cohorts. Though the replication attempt to weaken the overall support of this gene, given its relevant function and top rank of significance in the EWAS, our results call for future studies of larger aSAH cohorts to determine its relevance for the occurrence of DCI.

Systemic Immune-Inflammation Index Predicts Delayed Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral vasospasm is a feared complication of aneurysmal subarachnoid hemorrhage (SAH).

OBJECTIVE

To investigate the relationship of systemic inflammation, measured using the systemic immune-inflammation (SII) index, with delayed angiographic or sonographic vasospasm. We hypothesize that early elevations in SII index serve as an independent predictor of vasospasm.

METHODS

We retrospectively reviewed the medical records of 289 SAH patients for angiographic or sonographic evidence of delayed cerebral vasospasm. SII index [(neutrophils × platelets/lymphocytes)/1000] was calculated from laboratory data at admission and dichotomized based on whether or not the patient developed vasospasm. Multivariable logistic regression and receiver operating characteristic (ROC) analysis were performed to determine the ability of SII index to predict the development of vasospasm.

RESULTS

A total of 246 patients were included in our study, of which 166 (67.5%) developed angiographic or sonographic evidence of cerebral vasospasm. Admission SII index was elevated for SAH in patients with vasospasm compared to those without (P < .001). In univariate logistic regression, leukocytes, neutrophils, lymphocytes, neutrophil-lymphocyte ratio (NLR), and SII index were associated with vasospasm. After adjustment for age, aneurysm location, diabetes mellitus, hyperlipidemia, and modified Fisher scale, SII index remained an independent predictor of vasospasm (odds ratio 1.386, P = .003). ROC analysis revealed that SII index accurately distinguished between patients who develop vasospasm vs those who do not (area under the curve = 0.767, P < .001).

CONCLUSION

Early elevation in SII index can independently predict the development of delayed cerebral vasospasm in aneurysmal SAH.

Role of platelets in the pathogenesis of delayed injury after subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) patients develop delayed cerebral ischemia and delayed deficits (DCI) within 2 weeks of aneurysm rupture at a rate of approximately 30%. DCI is a major contributor to morbidity and mortality after SAH. The cause of DCI is multi-factorial with contributions from microthrombi, blood vessel constriction, inflammation, and cortical spreading depolarizations. Platelets play central roles in hemostasis, inflammation, and vascular function. Within this review, we examine the potential roles of platelets in microthrombi formation, large artery vasospasm, microvessel constriction, inflammation, and cortical spreading depolarization. Evidence from experimental and clinical studies is provided to support the role(s) of platelets in each pathophysiology which contributes to DCI. The review concludes with a suggestion for future therapeutic targets to prevent DCI after aSAH.

Systemic immune-inflammation index predicts the outcome after aneurysmal subarachnoid hemorrhage

Systemic inflammatory response is closely related to the pathogenesis and prognosis in critical patients. Recently, systemic immune-inflammation index (SII), an indicator of systemic inflammatory response, was proved to predict the outcome in cancerous and non-cancerous diseases. The aim of this study is to investigate the association between SII on admission and 6-month outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). The clinical data and prognosis of 76 patients with aSAH were analyzed. The 6-month outcome was assessed by the modified Rankin scale(mRS). The unfavorable outcome was defined as mRS score ≥ 3. In addition, multivariate analysis was conducted to investigate factors independently associated with the favorable outcome. Receiver operating characteristic (ROC) curve analysis was undertaken to identify the best cut-off value of SII for the discriminate between favorable and unfavorable outcome in these patients. Thirty-six patients (47.4%) in our study had an unfavorable outcome (mRS ≥ 3) at 6 months, and twenty-four (66.7%) of them were in the high-SII group. A significantly higher SII on admission was observed in patients with unfavorable functional outcome at 6 months. Binary logistic regression analysis showed that there was an independent association between SII on admission and 6-month clinical outcome (adjusted OR = 4.499, 95%CI: 1.242-16.295, P < 0.05). The AUC of the SII for predicting unfavorable outcome was 0.692 (95% CI: 0.571-0.814, P < 0.05). Systemic immune-inflammation index (SII) could be a novel independent prognostic factor for aSAH patients at the early stage of the disease.

Increased Systemic Immune-Inflammation Index Is Associated With Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage Patients

Background: Systemic immune-inflammation index (SII) is a novel biomarker that reflects the state of a patient's inflammatory and immune status. This study aimed to determine the clinical significance of SII as a predictor of delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (SAH).

Methods: Retrospective data were collected from aneurysmal SAH patients who had been admitted to our hospital between January 2015 and October 2019. Both univariate and multivariate analyses were performed to investigate whether SII was an independent predictor of DCI. In addition, the receiver operating characteristic (ROC) curve and area under the curve (AUC) were also evaluated.

Results: There were 333 patients with aneurysmal SAH included in this study. Multivariate logistic analysis revealed that a modified Fisher grade 3 and 4 score [odds ratio (OR) = 7.851, 95% confidence interval (CI): 2.312–26.661, P = 0.001] and elevated SII (OR = 1.001, 95% CI: 1.001–1.002, P < 0.001) were independent risk factors for DCI. ROC curves showed that SII could predict DCI with an AUC of 0.860 (95% CI: 0.818–0.896, P < 0.001). The optimal cut-off value for SII to predict DCI was 1,424, and an SII ≥ 1,424 could predict DCI with a sensitivity of 93.1% and a specificity of 68.1%. Patients with higher SII value on admission tended to have higher incidence of acute hydrocephalus and DCI, greater modified Fisher and Hunt-Hess scales, and poorer outcomes.

Conclusions: SII is an independent predictor of DCI in patients with aneurysmal SAH. The SII system can be implemented in a routine clinical setting to help clinicians diagnose patients with high risk of DCI.

Associations between C-reactive protein and white blood cell count, occurrence of delayed cerebral ischemia and poor outcome following aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

This review and meta-analysis investigated associations of systemic inflammatory marker C-reactive protein (CRP) and white blood cell count (WBC) with occurrence of delayed cerebral ischemia (DCI) and poor functional outcome after aneurysmal subarachnoid hemorrhage (aSAH). Pubmed, EMBASE, and CENTRAL databases were searched until November 30, 2019, selecting prospective and retrospective studies of patients with spontaneous SAH due to ruptured aneurysm. Outcome measures were occurrence of DCI, defined as new focal neurological deficit or a deterioration of consciousness; and/or a new infarct on computed tomography or magnetic resonance imaging that was not visible initially. Occurrence of poor functional outcome at follow-up were measured by modified Rankin Scale or Glasgow outcomes scale. Fifteen studies analyzing data of 3268 patients with aSAH were included. Meta-analysis revealed early increase in CRP was significantly associated with higher risk of occurrence of DCI (pooled OR 1.30, 95% CI 1.10-1.54; P = 0.002), whereas not with poor functional outcome (pooled OR 1.02, 95% CI 1.00-1.04, P = 0.052). No significant associations between early increase in WBC and DCI (pooled OR 1.13, 95% CI 0.95-1.34; P = 0.179) were observed, whereas increase in WBC was significantly associated with increased risk of poor functional outcome (pooled OR 1.17, 95% CI 1.07-1.28, P = 0.001). Early increase in blood CRP appears to correlate with DCI after SAH, while increase in WBC correlates with poor functional outcome. However, strong conclusion cannot be made due to the small study number, between-study heterogeneity and suspicion of uncontrolled factors. Whether early phase CRP and WBC may serve as prognostic markers for aSAH needs more investigation.

PaCO2-management in the neuro-critical care of patients with subarachnoid hemorrhage

The partial pressure of carbon dioxide (PaCO2) in the arterial blood is a strong vasomodulator affecting cerebral blood flow and the risk of cerebral edema and ischemia after acute brain injury. In turn, both complications are related to poor outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). We aimed to analyze the effect of PaCO2 levels on the course and outcome of aSAH. All patients of a single institution treated for aSAH over 13.5 years were included (n = 633). Daily PaCO2 values from arterial blood gas measurements were recorded for up to 2 weeks after ictus. The study endpoints were: delayed cerebral ischemia (DCI), need for decompressive craniectomy due to increased intracranial pressure > 20 mmHg refractory to conservative treatment and poor outcome at 6-months follow-up (modified Rankin scale > 2). By correlations with the study endpoints, clinically relevant cutoffs for the 14-days mean values for the lowest and highest daily PaCO2 levels were defined by receiver operating characteristic curve analysis. Association with the study endpoints for the identifies subgroups was analyzed using multivariate analysis. The optimal range for PaCO2 values was identified between 30 and 38 mmHg. ASAH patients with poor initial condition (WFNS 4/5) were less likely to show PaCO2 values within the range of 30-38 mmHg (p < 0.001, OR = 0.44). In the multivariate analysis, PaCO2 values between 30 and 38 mmHg were associated with a lower risk for decompressive craniectomy (p = 0.042, aOR = 0.27), DCI occurrence (p = 0.035; aOR = 0.50), and poor patient outcome (p = 0.004; aOR = 0.42). The data from this study shows an independent positive association between low normal mean PaCO2 values during the acute phase of aSAH and patients' outcome. This effect might be attributed to the reduction of intracranial hypertension and alterations in the cerebral blood flow.

Clinical significance of platelet to neutrophil ratio and platelet to lymphocyte ratio in patients with aneurysmal subarachnoid hemorrhage

The aim of study was aimed to investigate associations of platelet-to-neutrophil ratio (PNR) and platelet-to-lymphocyte ratio (PLR) on admission with clinical outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH). A retrospective analysis was performed on patients who were treated for aSAH. Unfavorable clinical outcome was defined as Modified Rankin Scale (mRS) score of 3-6 at 90-days. Receiver operating characteristic curve analysis was performed to detect optimal cutoff values of PNR and PLR for predicting clinical outcomes. Logistic regression was used to explore associations of PNR and PLR with clinical outcomes. A total of 544 patients with aSAH were enrolled. Of them, 152 (29.9%) had unfavorable clinical outcome. Optimal cutoff values of PNR and PLR to predict clinical outcomes at 90 days after aSAH were 25 and 130, respectively (P < 0.001 and <0.001, respectively). In multivariate logistic regression analysis, PNR <25 and PLR ≥ 130 were associated with unfavorable clinical outcome at 90 days after aSAH (odds ratio [OR]: 1.81; 95% confidence interval [CI]: 1.23-3.69; P = 0.018 and OR: 1.56; 95% CI: 1.18-2.62; P = 0.031, respectively). PNR and PLR as novel inflammatory biomarkers could predict the clinical outcome after aSAH. PNR <22 and PLR ≥ 130 were associated with unfavorable clinical outcome at 90 days after aSAH.

Delayed Cerebral Ischemia after Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) is the most feared complication of aneurysmal subarachnoid hemorrhage (aSAH). It increases the mortality and morbidity associated with aSAH. Previously, large cerebral artery vasospasm was thought to be the sole major contributing factor associated with increased risk of DCI. Recent literature has challenged this concept. We conducted a literature search using PUBMED as the prime source of articles discussing various other factors which may contribute to the development of DCI both in the presence or absence of large cerebral artery vasospasm. These factors include microvascular spasm, micro-thrombosis, cerebrovascular dysregulation, and cortical spreading depolarization. These factors collectively result in inflammation of brain parenchyma, which is thought to precipitate early brain injury and DCI. We conclude that diagnostic modalities need to be refined in order to diagnose DCI more efficiently in its early phase, and newer interventions need to be developed to prevent and treat this condition. These newer interventions are currently being studied in experimental models. However, their effectiveness on patients with aSAH is yet to be determined.

Molecular Mechanisms of Neuroimmune Crosstalk in the Pathogenesis of Stroke

Stroke disrupts the homeostatic balance within the brain and is associated with a significant accumulation of necrotic cellular debris, fluid, and peripheral immune cells in the central nervous system (CNS). Additionally, cells, antigens, and other factors exit the brain into the periphery via damaged blood–brain barrier cells, glymphatic transport mechanisms, and lymphatic vessels, which dramatically influence the systemic immune response and lead to complex neuroimmune communication. As a result, the immunological response after stroke is a highly dynamic event that involves communication between multiple organ systems and cell types, with significant consequences on not only the initial stroke tissue injury but long-term recovery in the CNS. In this review, we discuss the complex immunological and physiological interactions that occur after stroke with a focus on how the peripheral immune system and CNS communicate to regulate post-stroke brain homeostasis. First, we discuss the post-stroke immune cascade across different contexts as well as homeostatic regulation within the brain. Then, we focus on the lymphatic vessels surrounding the brain and their ability to coordinate both immune response and fluid homeostasis within the brain after stroke. Finally, we discuss how therapeutic manipulation of peripheral systems may provide new mechanisms to treat stroke injury.

Prognostic molecular markers for motor recovery in acute hemorrhagic stroke: A systematic review

BACKGROUND AND AIMS

Molecular biomarkers are associated with poor prognosis in ischemic stroke individuals. However, it might not be generalizable to post-acute hemorrhagic stroke since the underlying mechanisms of this brain damage differ from those found in ischemic stroke. The main purpose of this review was to synthesize the potential predictive molecular biomarkers for motor recovery following acute hemorrhagic stroke.

MATERIALS AND METHODS

An electronic search was conducted by 2 independent reviewers in the following databases: PubMed (Medline), EMBASE, Web of Science, and CINAHL. We included studies that addressed the following: collected blood, urine, or cerebrospinal fluid samples within 72 h after hemorrhagic stroke and that reported the prognostic association with functional motor recovery for each molecular biomarker. Screening of titles, abstracts, and full texts and data extraction were undertaken independently by pairs of reviewers.

RESULTS

Twelve thousand, five hundred and sixty-four studies were identified and 218 were considered eligible. Finally, we included 70 studies, with 96 biomarkers analyzed, of which 61 were considered as independent prognostic biomarkers, and 10 presented controversial results.

CONCLUSION

This systematic review shows that motor functional recovery can be predicted by 61 independent prognostic molecular biomarkers assessed in the acute phase after a hemorrhagic stroke.

Effectiveness comparisons of drug therapies for postoperative aneurysmal subarachnoid hemorrhage patients: network meta‑analysis and systematic review

Objective

To compare the effectiveness of various drug interventions in improving the clinical outcome of postoperative patients after aneurysmal subarachnoid hemorrhage (aSAH) and assist in determining the drugs of definite curative effect in improving clinical prognosis.

Methods

Eligible Randomized Controlled Trials (RCTs) were searched in databases of PubMed, EMBASE, and Cochrane Library (inception to Sep 2020). Glasgow Outcome Scale (GOS) score, Extended Glasgow Outcome Scale (GOSE) score or modified Rankin Scale (mRS) score was used as the main outcome measurements to evaluate the efficacy of various drugs in improving the clinical outcomes of postoperative patients with aSAH. The network meta-analysis (NMA) was conducted based on a random-effects model, dichotomous variables were determined by using odds ratio (OR) with 95% confidence interval (CI), and a surface under the cumulative ranking curve (SUCRA) was generated to estimate the ranking probability of comparative effectiveness among different drug therapies.

Results

From the 493 of initial citation screening, forty-four RCTs (n = 10,626 participants) were eventually included in our analysis. Our NMA results showed that cilostazol (OR = 3.35,95%CI = 1.50,7.51) was the best intervention to improve the clinical outcome of patients (SUCRA = 87.29%, 95%CrI 0.07–0.46). Compared with the placebo group, only two drug interventions [nimodipine (OR = 1.61, 95%CI 1.01,2.57) and cilostazol (OR = 3.35, 95%CI 1.50, 7.51)] achieved significant statistical significance in improving the clinical outcome of patients.

Conclusions

Both nimodipine and cilostazol have exact curative effect to improve the outcome of postoperative patients with aSAH, and cilostazol may be the best drug to improve the outcome of patients after aSAH operation. Our study provides implications for future studies that, the combination of two or more drugs with relative safety and potential benefits (e.g., nimodipine and cilostazol) may improve the clinical outcome of patients more effectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02303-8.

Hemostasis and Fibrinolysis following Aneurysmal Subarachnoid Hemorrhage: A Systematic Review on Additional Knowledge from Dynamic Assays and Potential Treatment Targets

Mortality after aneurysmal subarachnoid hemorrhage (aSAH) is augmented by rebleeding and delayed cerebral ischemia (DCI). A range of assays evaluating the dynamic process of blood coagulation, from activation of clotting factors to fibrinolysis, has emerged and a comprehensive review of hemostasis and fibrinolysis following aSAH may reveal targets of treatment. We conducted a systematic review of existing literature assessing coagulation and fibrinolysis following aSAH, but prior to treatment. PubMed, Embase, and Web of Science were searched on November 18, 2020, without time boundaries. In total, 45 original studies were eventually incorporated into this systematic review, divided into studies presenting data only from conventional or quantitative assays (n = 22) and studies employing dynamic assays (n = 23). Data from conventional or quantitative assays indicated increased platelet activation, whereas dynamic assays detected platelet dysfunction possibly related to an increased risk of rebleeding. Secondary hemostasis was activated in conventional, quantitative, and dynamic assays and this was related to poor neurological outcome and mortality. Studies systematically investigating fibrinolysis were sparse. Measurements from conventional or quantitative assays, as well as dynamic fibrinolysis assays, revealed conflicting results with normal or increased lysis and changes were not associated with outcome. In conclusion, dynamic assays were able to detect reduced platelet function, not revealed by conventional or quantitative assays. Activation of secondary hemostasis was found in both dynamic and nondynamic assays, while changes in fibrinolysis were not convincingly demonstrable in either dynamic or conventional or quantitative assays. Hence, from a mechanistic point of view, desmopressin to prevent rebleeding and heparin to prevent DCI may hold potential as therapeutic options. As changes in fibrinolysis were not convincingly demonstrated and not related to outcome, the use of tranexamic acid prior to aneurysm closure is not supported by this review.

α7-Acetylcholine Receptor Signaling Reduces Neuroinflammation After Subarachnoid Hemorrhage in Mice

Aneurysmal subarachnoid hemorrhage (aSAH) causes a robust inflammatory response which leads worse brain injury and poor outcomes. We investigated if stimulation of nicotinic acetylcholine α7 receptors (α7-AChR) (receptors shown to have anti-inflammatory effects) would reduce inflammation and improve outcomes. To investigate the level of peripheral inflammation after aSAH, inflammatory markers were measured in plasma samples collected in a cohort of aSAH patients. To study the effect of α7-AChR stimulation, SAH was induced in adult mice which were then treated with a α7-AChR agonist, galantamine, or vehicle. A battery of motor and cognitive tests were performed 24 h after subarachnoid hemorrhage. Mice were euthanized and tissue collected for analysis of markers of inflammation or activation of α7-AChR-mediated transduction cascades. A separate cohort of mice was allowed to survive for 28 days to assess long-term neurological deficits and histological outcome. Microglia cell culture subjected to hemoglobin toxicity was used to assess the effects of α7-AChR agonism. Analysis of eighty-two patient plasma samples confirmed enhanced systemic inflammation after aSAH. α7-AChR agonism reduced neuroinflammation at 24 h after SAH in male and female mice, which was associated with improved outcomes. This coincided with JAK2/STAT3 and IRAK-M activity modulations and a robust improvement in neurological/cognitive status that was effectively reversed by interfering with various components of these signaling pathways. Pharmacologic inhibition partially reversed the α7-AChR agonist's benefits, supporting α7-AChR as a target of the agonist's therapeutic effect. The cell culture experiment showed that α7-AChR agonism is directly beneficial to microglia. Our results demonstrate that activation of α7-AChR represents an attractive target for treatment of SAH. Our findings suggest that α7-AChR agonists, and specifically galantamine, might provide therapeutic benefit to aSAH patients.

Systemic Inflammation Response Index and Systemic Immune-inflammation Index for Predicting the Prognosis of Patients with Aneurysmal Subarachnoid Hemorrhage

OBJECTIVES

Inflammatory response plays a pivotal role in the progress of aneurysmal subarachnoid hemorrhage (aSAH). As novel inflammatory markers, systemic inflammation response index (SIRI) and systemic immune-inflammation (SII) index could reflect clinical outcomes of patients with various diseases. The aim of this study was to ascertain whether initial SIRI and SII index were associated with prognosis of aSAH patients.

METHODS

A total of 680 patients with aSAH were enrolled. Their prognosis was evaluated with modified Rankin Scale (mRS) at 3 months, and unfavorable clinical outcome was defined as mRS score of 3-6. Receiver operating characteristic (ROC) curve analysis was performed to identify cutoff values of SIRI and SII index for predicting clinical outcomes. Univariate and multivariate regression analyses were performed to explore relationships of SIRI and SII index with prognosis of patients.

RESULTS

Optimal cutoff values of SIRI and SII index to discriminate between favorable and unfavorable clinical outcomes were 3.2 × 10⁹/L and 960 × 10⁹/L, respectively (P < 0.001 and 0.004, respectively). In multivariate analysis, SIRI value ≥ 3.2 × 10⁹/L (odds ratio [OR]: 1.82, 95% CI: 1.46-3.24; P = 0.021) and SII index value ≥ 960 × 10⁹/L (OR: 1.68, 95% CI: 1.24-2.74; P = 0.040) were independent predicting factors for poor prognosis after aSAH.

CONCLUSIONS

SIRI and SII index values are associated with clinical outcomes of patients with aSAH. Elevated SIRI and SII index could be independent predicting factors for a poor prognosis after aSAH.

Platelet Receptor Activity for Predicting Survival in Patients with Intracranial Bleeding

Blood coagulation disorders in patients with intracranial bleeding as a result of head injuries or ruptured aneurysms are a diagnostic and therapeutic problem and appropriate assessments are needed to limit CNS damage and to implement preventive measures. The aim of the study was to monitor changes in platelet aggregation and to assess the importance of platelet dysfunction for predicting survival. Platelet receptor function analysis was performed using the agonists arachidonic acid (ASPI), adenosine diphosphate (ADP), collagen (COL), thrombin receptor activating protein (TRAP), ristocetin (RISTO) upon admission to the ICU and on days 2, 3, and 5. On admission, the ASPI, ADP, COL, TRAP, and RISTO tests indicated there was reduced platelet aggregation, despite there being a normal platelet count. In ‘Non-survivors’, the platelet response to all agonists was suppressed throughout the study period, while in ‘Survivors’ it improved. Measuring platelet function in ICU patients with intracranial bleeding is a strong predictor related to outcome: patients with impaired platelet aggregation had a lower 28-day survival rate compared to patients with normal platelet aggregation (log-rank test p = 0.014). The results indicated that measuring platelet aggregation can be helpful in the early detection, diagnosis, and treatment of bleeding disorders.

Effects of post-interventional antiplatelet therapy on angiographic vasospasm, delayed cerebral ischemia, and clinical outcome after aneurysmal subarachnoid hemorrhage: a single-center experience

Platelet activation has been postulated to be involved in the pathogenesis of delayed cerebral ischemia (DCI) and cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to investigate potentially beneficial effects of antiplatelet therapy (APT) on angiographic CVS, DCI-related infarction and functional outcome in endovascularly treated aSAH patients. Retrospective single-center analysis of aSAH patients treated by endovascular aneurysm obliteration. Based on the post-interventional medical regime, patients were assigned to either an APT group or a control group not receiving APT. A subgroup analysis separately investigated those APT patients with aspirin monotherapy (MAPT) and those receiving dual treatment (aspirin plus clopidogrel, DAPT). Clinical and radiological characteristics were compared between groups. Possible predictors for angiographic CVS, DCI-related infarction, and an unfavorable functional outcome (modified Rankin scale ≥ 3) were analyzed. Of 160 patients, 85 (53%) had received APT (n = 29 MAPT, n = 56 DAPT). APT was independently associated with a lower incidence of an unfavorable functional outcome (OR 0.40 [0.19-0.87], P = 0.021) after 3 months. APT did not reduce the incidence of angiographic CVS or DCI-related infarction. The pattern of angiographic CVS or DCI-related infarction as well as the rate of intracranial hemorrhage did not differ between groups. However, the lesion volume of DCI-related infarctions was significantly reduced in the DAPT subgroup (P = 0.011). Post-interventional APT in endovascularly treated aSAH patients is associated with better functional outcome at 3 months. The beneficial effect of APT might be mediated by reduction of the size of DCI-related infarctions.

Interleukin 6 in cerebrospinal fluid is a biomarker for delayed cerebral ischemia (DCI) related infarctions after aneurysmal subarachnoid hemorrhage

Interleukin 6 (IL-6) is a prominent proinflammatory cytokine and has been discussed as a potential biomarker for delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage. In the present study we have analyzed the time course of serum and cerebrospinal fluid (CSF) IL-6 levels in 82 patients with severe aneurysmal subarachnoid hemorrhage (SAH) requiring external ventricular drains in correlation to angiographic vasospasm, delayed cerebral ischemia, secondary infarctions and other clinical parameters. We observed much higher daily mean IL-6 levels (but also large interindividual variations) in the CSF than the serum of the patients with a peak between days 4 and 14 including a maximum on day 5 after SAH. Individual CSF peak levels correlated significantly with DCI (mean day 4–14 peak, DCI: 26,291 ± 24,159 pg/ml vs. no DCI: 16,184 ± 13,163 pg/ml; P = 0.023). Importantly, CSF IL-6 levels differed significantly between cases with DCI and infarctions and patients with DCI and no infarction (mean day 4–14 peak, DCI with infarction: 37,209 ± 26,951 pg/ml vs. DCI, no infarction: 15,123 ± 11,239 pg/ml; P = 0.003), while findings in the latter patient group were similar to cases with no vasospasm (mean day 4–14 peak, DCI, no infarction: 15,123 ± 11,239 vs. no DCI: 15,840 ± 12,979; P = 0.873). Together, these data support a potential role for elevated CSF IL-6 levels as a biomarker for DCI with infarction rather than for DCI in general. This fits well with a growing body of evidence linking neuroinflammation to ischemia and infarction, but (together with the large interindividual variations observed) limits the diagnostic usefulness of CSF IL-6 levels in SAH patients.