Serum calcium as prognosticator in ischemic stroke

Autologous mitochondrial transplant for acute cerebral ischemia: Phase 1 trial results and review

The results of a Phase 1 trial of autologous mitochondrial transplantation for the treatment of acute ischemic stroke during mechanical thrombectomy are presented. Standardized methods were used to isolate viable autologous mitochondria in the acute clinical setting, allowing for timely transplantation within the ischemic window. No significant adverse events were observed with the endovascular approach during reperfusion therapy. Safety outcomes in study participants were comparable to those of matched controls who did not undergo transplantation. This study represents the first use of mitochondrial transplantation in the human brain, highlighting specific logistical challenges related to the acute clinical setting, such as limited tissue samples and constrained time for isolation and transplantation. We also review the opportunities and challenges associated with further clinical translation of mitochondrial transplantation in the context of acute cerebral ischemia and beyond.

Association between serum calcium and in-hospital mortality in intensive care unit patients with cerebral infarction: a cohort study

Background

The relationship between serum calcium levels and the prognosis of cerebral infarction remains controversial.

Purpose

This study aims to investigate the correlation between serum calcium levels and in-hospital mortality in critically ill patients with ischemic stroke admitted to the intensive care unit (ICU).

Methods

A retrospective cohort study was conducted using data from the MIMIC-IV database. Demographic and clinical data of all participants were collected including gender, age, hypertension, diabetes, myocardial infarction, heart failure, chronic obstructive pulmonary disease, hemoglobin, potassium, sodium, anion gap, platelets, white blood cells, glucose, creatinine, Glasgow coma score (GCS), IV-tPA administration (rt-PA), and mechanical thrombectomy (MT). The outcome measure was in-hospital death. Multivariable-adjusted logistic regression analysis, curve fitting, interaction analysis, and threshold effect analysis were employed to evaluate the relationship between serum calcium levels and in-hospital mortality among ICU patients with cerebral infarction.

Results

A total of 2,680 critically ill patients with cerebral infarction were enrolled, with a mean serum calcium level of 8.6 ± 0.8 mg/dL. The overall in-hospital mortality rate was 19.5%, where Group 1 (serum calcium < 8.0 mg/dL) had a mortality rate of 27.7%, Group 2 (serum calcium 8-9 mg/dL) had a rate of 19.8%, and Group 3 (serum calcium ≥ 9 mg/dL) had a rate of 13.9%. There was a non-linear, S-shaped relationship between serum calcium levels and in-hospital mortality. Serum calcium levels within the range of 7.70-9.50 mg/dL were found to be independently associated with increased in-hospital mortality in ICU patients with cerebral infarction. No significant interactions were detected in subgroup analyses, and the results of sensitivity analyses remained stable.

Conclusion

Serum calcium levels are independently associated with in-hospital mortality in critically ill patients with cerebral infarction in the ICU setting. Within the range of 7.70-9.50 mg/dL, lower serum calcium levels increase the risk of in-hospital death among these patients, emphasizing the importance of close monitoring by ICU physicians.

Association between serum calcium and prognosis in patients with acute ischemic stroke in ICU: analysis of the MIMIC-IV database

BACKGROUND

While serum Ca has proven to be a reliable predictor of mortality across various diseases, its connection with the clinical outcomes of ischemic stroke (IS) remains inconclusive. Our research aimed to explore the relationships between serum total Ca (tCa) and serum ionized Ca (iCa) and mortality among acute IS (AIS) patients.

METHODS

We gathered data from 1773 AIS patients in the Medical Information Mart for Intensive Care Database IV, including baseline demographic data, comorbidities, vital signs, laboratory-based data, and scoring systems. Endpoints for the study encompassed 30-d, 90-d, and 365-d all-cause mortalities. Employing restricted cubic spline Cox regression, we explored potential nonlinear relationships between admission serum iCa and tCa levels and mortality. Participants were categorized into four groups based on serum iCa and tCa quartiles. Multivariable Cox regression analysis was then conducted to evaluate the independent association of iCa and tCa quartiles with all-cause mortality.

RESULTS

The restricted cubic spline revealed a U-shaped association between iCa and 30-d and 90-d mortality (P<0.05), while the relationship between iCa and 365-d mortality was linear (P<0.05). After adjusting for confounders, multivariable Cox analysis demonstrated that the lowest serum iCa level quartile was independently associated with increased risks of 30-d, 90-d, and 365-d mortality. Similarly, the highest serum iCa level quartile was independently associated with increased risks of 30-d and 90-d mortality, but not 365-d mortality. Notably, serum tCa level showed no association with increased risks of 30-d, 90-d, and 365-d mortality.

CONCLUSIONS

Our findings suggest that serum iCa, rather than tCa, is linked to ischemic stroke prognosis. Both high and low serum iCa levels are associated with poor short-term prognosis, while only low serum iCa is associated with poor long-term prognosis in AIS patients.

Elevated Calcium after Acute Ischemic Stroke Predicts Severity and Prognosis

The aim of this study is to investigate whether there is a correlation between serum calcium levels and clinical severity or functional outcome at discharge in Chinese patients with acute ischemic stroke. Data from 339 patients admitted to our hospital between July 2020 and July 2021 were analyzed. Baseline demographic and clinical information was collected within 24 h of admission, including serum calcium levels, stroke severity (measured by the National Institutes of Health Stroke Scale [NIHSS] score), and lesion volumes. The modified Rankin Scale [mRS] assessed functional outcomes at discharge. Our analysis showed that the median age of patients included in the study was 65 years (interquartile range [IQR], 60-70), and 60.8% were men. We found a positive correlation between serum calcium levels and stroke severity (r[spearman] = 0.266, P < 0.001), with calcium levels increasing as stroke severity increased. In a subgroup of 188 patients with available MRI data, serum calcium concentrations positively correlated with infarct size. Furthermore, in multivariate analysis, a calcium serum level in the highest quartile was associated with a higher risk of unfavorable outcome (odds ratios [OR] = 3.27; 95% confidence intervals [CI] = 1.91-5.59; P < 0.001). In conclusion, our study indicates that higher calcium serum levels are associated with stroke severity and early neurologic outcome after acute ischemic stroke, indicating that calcium may serve as a prognostic biomarker for stroke in Chinese patients.

Association of Serum Calcium With Infarct Size and Severity in Acute Ischemic Stroke: A Rural Hospital-Based Cross-Sectional Study

Background One of the major mediators of ischemic neuronal cell death is calcium. It has been found that elevated serum calcium is associated with a better prognosis in patients with ischemic stroke. This study highlights the association of serum calcium, albumin-corrected calcium, and ionic calcium with the size of acute ischemic stroke as well as severity outcome in terms of the National Institutes of Health Stroke Scale (NIHSS) score and Barthel Index. Methods This cross-sectional study was conducted on 85 cases of acute ischemic stroke (based on a computerized tomography scan of the brain) from September 2019 to October 2021. All included patients had undergone complete clinical history, systemic examination, as well as estimation of serum total calcium, albumin corrected calcium, and ionic calcium. NIHSS score and Barthel Index were used to access the severity of each subject.  Results A significant positive correlation was seen between infarct size with NIHSS with a correlation coefficient of 0.35. A significant negative correlation was seen between infarct size with serum calcium, albumin-corrected calcium, and Barthel Index with a correlation coefficient of -0.483, -0.354, and -0.365 respectively. No correlation was seen between infarct size and ionic calcium with a correlation coefficient of 0.082. Conclusion It can be concluded that higher normal levels of serum calcium and albumin-corrected calcium are associated with a smaller-sized infarct and had less severity index among patients with acute ischemic stroke.

The association of admission ionized calcium with outcomes of thrombolysed patients with anterior circulation ischemic stroke

BACKGROUND AND PURPOSE

The relationship between ionized calcium and prognosis of ischemic stroke is controversial. We aim to determine the relationship of admission ionized calcium levels with acute ischemic stroke (AIS) after intravenous thrombolysis (IVT).

METHODS

Consecutive anterior circulation AIS patients treated with recombinant tissue plasminogen activator (rt-PA) were retrospectively enrolled. According to ionized calcium quartiles, the patients were divided into four groups and clinical data were analyzed between groups. Ionized calcium was entered into logistic regression analysis in two models, separately: model 1, calcium as a continuous variable (per 1-mmol/L increase), and model 2, calcium as the four-categorized variable (being collapsed into quartiles: Q1-Q4). Early neurologic improvement (ENI) was defined as improvement of four or more points at 24 h after intravenous rt-PA, while long-term good outcome as the modified Rankin Scale (mRS) 0-1 at 90 days.

RESULTS

A total of 546 patients met the study criteria (mean age was 63.51 ± 11.26 years and 365 [66.8%] were men). The median admission National Institute of Health Stroke Scale was 9 (range 4 to 15). When not adjusted, in model 1: ionized calcium was related to good outcome (odds ratio [OR] 69.061, 95%CI: 1.638-2911.111, p=0.027), but not ENI (OR 14.097, 95%CI: 0.133-1492.596, p=0.266); in model 2: compared with Q4, while good outcome was less common in Q1 (OR 0.623, 95%CI: 0.388-0.999, p=0.049). After adjusting for confounding factors, calcium in Q2 (OR 0.502, 95%CI: 0.253-0.997, p=0.049) was independently associated with ENI, but no matter as a continuous variable or categorized variable, ionized calcium displayed no association with a good outcome.

CONCLUSION

The current results found that ionized calcium might be associated with early neurological improvement, but had no association with 3 months' outcome in anterior circulation AIS patients after IVT.

Higher serum albumin-corrected calcium levels are associated with revascularization and poor outcome after mechanical thrombectomy

Background

Serum calcium abnormalities have been determined to be associated with the risk and outcome of stroke. The aim of the present study was to examine the associations of serum calcium with vascular recanalization, symptomatic intracranial haemorrhage and functional outcome in stroke patients after mechanical thrombectomy.

Methods

A total of 192 patients treated with mechanical thrombectomy for anterior circulation large vessel occlusion were consecutively included from August 2017 to June 2021. Serum calcium levels were measured on admission, and albumin-corrected calcium levels were calculated for subsequent analysis. Successful arterial revascularization was defined as a modified Thrombolysis in Cerebral Infarction scale score ≥ 2b. Symptomatic intracranial haemorrhage was assessed according to the European Cooperative Acute Stroke Study (ECASS) III criteria. Poor functional outcome was defined as a modified Rankin Scale score > 2 at 3 months.

Results

Patients with poor outcomes had higher albumin-corrected calcium levels than patients with good outcomes before (2.20 (2.10, 2.30) mmol/L vs. 2.13 (2.04, 2.24) mmol/L, P = 0.002), and after adjusting for other factors (AOR 95% CI, 1.812 (1.253, 2.621), P = 0.002). Patients with unsuccessful recanalization had higher albumin-corrected calcium levels than those with recanalization (2.26 (2.09, 2.46) mmol/L vs. 2.17 (2.07, 2.27) mmol/L, P = 0.029), and after adjusting for other factors (AOR 95% CI, 2.068 (1.214, 3.524)), P = 0.008). No association was found between albumin-corrected calcium and symptomatic intracranial haemorrhage.

Conclusions

Higher serum albumin-corrected calcium levels are independently associated with revascularization and poor outcome in stroke patients after mechanical thrombectomy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02856-2.

Admission Serum Calcium Level and Short-Term Mortality After Acute Ischemic Stroke: A Secondary Analysis Based on a Norwegian Retrospective Cohort

Background

Disturbed serum calcium levels are related to the risk of stroke. However, previous studies exploring the correlation between serum calcium and the clinical outcome of ischemic stroke (IS) have shown inconsistent results.

Object

The study aimed to investigate the relationship between admission serum calcium and 30-day mortality in patients with IS.

Methods

A total of 876 IS patients from a Norwegian retrospective cohort were included for secondary analysis. The exposure variable and the primary outcome were albumin-corrected serum calcium (ACSC) at baseline and all-cause mortality within 30 days after the first admission, respectively. Multivariable logistic regression analysis was used to estimate the risk of 30-day mortality according to ACSC levels. Moreover, the potential presence of a non-linear relationship was evaluated using two-piecewise linear regression with a smoothing function and threshold level analysis. The stability of the results was evaluated by unadjusted and adjusted models.

Results

The result of multiple regression analysis showed that ACSC at baseline was positively associated with the incidence of 30-day mortality after adjusting for the potential confounders (age, gender, serum glucose, hypertension, atrial fibrillation/atrial flutter, renal insufficiency, heart failure, chronic obstructive pulmonary disease, pneumonia, paralysis, and aphasia) (OR = 2.43, 95% CI 1.43–4.12). When ACSC was translated into a categorical variable, the ORs and 95% CIs in the second to the fourth quartile vs. the first quartile were 1.23 (0.56, 2.69), 1.16 (0.51, 2.65), and 2.13 (1.04, 4.38), respectively (P for trend = 0.03). Moreover, the results of two-piecewise linear regression and curve-fitting revealed a linear relationship between ACSC and 30-day mortality.

Conclusion

ACSC is positively associated with 30-day mortality in IS patients, and the relationship between them is linear.

Phosphodiesterase-5 Inhibitor Attenuates Anxious Phenotypes and Movement Disorder Induced by Mild Ischemic Stroke in Rats

Objective

Patients with mild ischemic stroke experience various sequela and residual symptoms, such as anxious behavior and deficits in movement. Few approaches have been proved to be effective and safe therapeutic approaches for patients with mild ischemic stroke by acute stroke. Sildenafil (SIL), a phosphodiesterase-5 inhibitor (PDE5i), is a known remedy for neurodegenerative disorders and vascular dementia through its angiogenesis and neurogenesis effects. In this study, we investigated the efficacy of PDE5i in the emotional and behavioral abnormalities in rats with mild ischemic stroke.

Methods

We divided the rats into four groups as follows (n=20, respectively) : group 1, naïve; group 2, middle cerebral artery occlusion (MCAo30); group 3, MCAo30+SIL-pre; and group 4, MCAo30+SIL-post. In the case of drug administration groups, single dose of PDE5i (sildenafil citrate, 20 mg/kg) was given at 30-minute before and after reperfusion of MCAo in rats. After surgery, we investigated and confirmed the therapeutic effect of sildenafil on histology, immunofluorescence, behavioral assays and neural oscillations.

Results

Sildenafil alleviated a neuronal loss and reduced the infarction volume. And results of behavior task and immunofluorescence shown possibility that anti-inflammation process and improve motor deficits sildenafil treatment after mild ischemic stroke. Furthermore, sildenafil treatment attenuated the alteration of theta-frequency rhythm in the CA1 region of the hippocampus, a known neural oscillatory marker for anxiety disorder in rodents, induced by mild ischemic stroke.

Conclusion

PDE5i as effective therapeutic agents for anxiety and movement disorders and provide robust preclinical evidence to support the development and use of PDE5i for the treatment of mild ischemic stroke residual disorders.

Calcium: More Than Bone? Implications for Clinical Practice and Theory

Serum calcium is routinely screened, but rarely scrutinized in the context of normal, physiologic functioning. This brief review strives to explore the implications of serum calcium, suggests guidelines for its interpretation, and discusses the implications of high, low, and “normocalcemia” in the clinical setting. We find that serum Ca²⁺ concentrations are a valuable prognostic indicator in routine metabolic workups and advocate for greater attention, on behalf of the provider, to variations in a patient’s calcemic status. Variations in calcemic status are primarily tied to malignancy, impaired parathyroid hormone (PTH) secretion, defects in vitamin D synthesis, insulin-like growth factor 1 (IGF-1) fluctuation, genetic syndromes (DiGeorge syndrome) and calcium-sensing receptor (CaSR) mutation. Prognostic implications for high and low serum Ca²⁺ include, but are not limited to, increased thromboembolic and major adverse cardiovascular event (MACE) risk, cardiac remodeling, hypertension, cognitive decline, and insulin resistance.

Role of Calcium Homeostasis in Ischemic Stroke: A Review

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Stroke is the second most common cause of death worldwide. It occurs due to the insufficient supply of oxygen-rich blood to the brain. It is a complex disease with multiple associated risk factors including smoking, alcoholism, age, sex, ethnicity, etc. Calcium ions are known to play a vital role in cell death pathways, which is a ubiquitous intracellular messenger during and immediately after an ischemic period. Disruption in normal calcium hemostasis is known to be a major initiator and activator of the ischemic cell death pathway. Under Ischemic stroke conditions, glutamate is released from the neurons and glia which further activates the N-methyl-D-aspartate (NMDA) receptor and triggers the rapid translocation of Ca2+ from extracellular to intracellular spaces in cerebral tissues and vice versa. Various studies indicated that Ca2+ could have harmful effects on neurons under acute ischemic conditions. Mitochondrial dysfunction also contributes to delayed neuronal death, and it was established decades ago that massive calcium accumulation triggers mitochondrial damage. Elevated Ca2+ levels cause mitochondria to swell and release their contents. As a result oxidative stress and mitochondrial calcium accumulation activate mitochondrial permeability transition and lead to depolarization-coupled production of reactive oxygen species. This association between calcium levels and mitochondrial death suggests that elevated calcium levels might have a role in the neurological outcome in ischemic stroke. Previous studies have also reported that elevated Ca2+ levels play a role in the determination of infarct size, outcome, and recurrence of ischemic stroke. The current review has been compiled to understand the multidimensional role of altered Ca2+ levels in the initiation and alteration of neuronal death after ischemic attack. The underlying mechanisms understood to date have also been discussed.

Association between electrolyte levels at presentation and hematoma expansion and outcome in spontaneous intracerebral hemorrhage: A systematic review

PURPOSE

To assess the association between specific electrolyte levels (sodium, potassium, calcium, magnesium, and phosphorus) on presentation and hematoma expansion (HE) and outcome in intracerebral hemorrhage (ICH).

METHODS

This review was conducted in accordance with the PRISMA statement recommendations. Three databases were searched (Pubmed, Scopus, and Cochrane). Risk of bias was computed using the Newcastle-Ottawa Scale tool.

RESULTS

18 full-text articles were included in this systematic review including 10,385 ICH patients. Hypocalcemia was associated with worse short-term outcome in four studies, and two other studies were neutral. All studies investigating HE in hypocalcemia (n = 5) reported an association between low calcium level and HE. Hyponatremia (Na < 135 mEq/L) was shown to correlate with worse short-term outcome in two studies, and worse long-term outcome in one. There was one report showing no association between sodium level and HE. Hypomagnesemia was shown to be associated with worse short-term outcome in one study, while other reports were neutral. Studies evaluating hypophosphatemia or hypokalemia in ICH were limited, with no demonstrable significant effect on outcome.

CONCLUSION

This review suggests a significant association between hypocalcemia, hyponatremia and, of lesser degree, hypomagnesemia on admission and HE or worse outcome in ICH.

Liquid biopsy markers for stroke diagnosis

INTRODUCTION

There is a short time window (4.5 h) for the effective treatment of acute ischemic stroke (AIS), which uses recombinant tissue plasminogen activator (rt-PA). Unfortunately, this short therapeutic timeframe is a contributing factor to the relatively small number of patients (~7%) that receive rt-PA. While neuroimaging is the major diagnostic for AIS, more timely decisions could be made using a molecular diagnostic.

AREAS COVERED

In this review, we survey neuroimaging techniques used to diagnose stroke and their limitations. We also highlight the potential of various molecular/cellular biomarkers, especially peripheral blood-based (i.e. liquid biopsy) biomarkers, for diagnosing stroke to allow for precision decisions on managing stroke in a timely manner. Both protein and nucleic acid molecular biomarkers are reviewed. In particular, mRNA markers are discussed for AIS and hemorrhagic stroke diagnosis sourced from both cells and extracellular vesicles.

EXPERT OPINION

While there are a plethora of molecular markers for stroke diagnosis that have been reported, they have yet to be FDA-cleared. Possible reasons include the inability for these markers to appear in sufficient quantities for highly sensitive clinical decisions within the rt-PA therapeutic time.

The Role of Serum Calcium Level in Intracerebral Hemorrhage Hematoma Expansion: Is There Any?

Spontaneous intracerebral hemorrhage (ICH) is a devastating form of stroke, with a high rate of mortality and morbidity. Even with the best current medical or surgical interventions, outcomes remain poor. The location and initial hematoma volume are strong predictors of mortality. Hematoma expansion (HE) is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for HE have been identified, including baseline ICH volume, anticoagulation, and computed tomography angiography spot signs. Recent studies have shown the correlation of serum calcium (Ca⁺⁺) levels on admission with HE. Low serum Ca⁺⁺ level has been associated with larger hematoma volume at the time of presentation, HE, and worse outcome. Although the causal and mechanistic links between low serum Ca⁺⁺ level and HE are not well understood, several mechanisms have been proposed including coagulopathy, platelet dysfunction, and higher blood pressure (BP) in the context of low serum Ca⁺⁺ level. However, low serum Ca⁺⁺ level might be only a biomarker of the adaptive response due to acute inflammatory response following acute ICH. The purpose of the current review is to discuss the evidence regarding the possible role of low serum Ca⁺⁺ level on HE in acute ICH.

Acid-Base and Electrolyte Changes Drive Early Pathology in Ischemic Stroke

Emergent large vessel occlusion accounts for 20-40% of ischemic strokes and is the most debilitating form of stroke. Some of the earliest changes in response to ischemic stroke occur in blood gases and electrolytes. These biochemical changes occur within minutes after occlusion in experimental models of stroke and can be utilized to predict stroke outcomes. The majority of ELVO stroke patients are middle-aged to elderly and are of both sexes, revealing that there is an age and sex mismatch between ischemic stroke patients and animal models, since most experimental studies use young male rats. Rethinking of the animal models should be considered, especially in encouraging the use of aged male and female rats with comorbidities to more closely mirror human populations. Mechanical thrombectomy provides a unique opportunity for researchers to further this work by expanding the collection and analysis of blood samples that are adjacent to the thrombus. To understand the complexity of stroke, researchers can analyze these tissues for different molecular targets that occur in response to ischemic stroke. This information may aid in the reduction of symptom burden for individuals diagnosed with ischemic stroke. Investigators should also focus on data from ischemic stroke patients and attempt to discover target molecules and then in animal models to establish mechanism, which will aid in the development of new stroke therapies. This review discusses the translation of these studies to the human patient to develop the capability to predict stroke outcomes. Future studies are needed to identify molecular targets to predict the risk of worsened long-term outcomes and/or increased risk for mortality.

Early acid/base and electrolyte changes in permanent middle cerebral artery occlusion: Aged male and female rats

BACKGROUND

Early changes in acid/base and electrolyte concentrations could provide insights into the development of neuropathology at the onset of stroke. We evaluated associations between acid/base and electrolyte concentrations, and outcomes in permanent middle cerebral artery occlusion (pMCAO) model.

METHODS

18-month-old male and female Sprague-Dawley rats underwent pMCAO. Pre-, post- (7 min after occlusion), and at 72 hr of pMCAO venous blood samples provided pH, carbon dioxide, oxygen, glucose, hematocrit, hemoglobin, and electrolyte values of ionized calcium, potassium, and sodium. Multiple linear regression determined predictors of infarct and edema volumes from these values, Kaplan-Meier curve analyzed morality between males and females at 72 hr, and a Cox regression model was used to determine predictors for mortality.

RESULTS

Analysis indicated significant differences in acid/base balance and electrolyte levels in aged rats not dependent on sex between the three time points in the pMCAO model. Changes in pH (from pre- to post and post- to 72 hr) and changes in sodium and ionized calcium (from post- to 72 hr) were predictors of infarct volume and edema volume, respectively. Cox Regression revealed there is a 3.25 times increased risk for mortality based on changes in bicarbonate (pre- to post-MCAO).

CONCLUSIONS

These early venous blood changes in acid/base balance and electrolytes can be used to predict stroke outcomes in our rat model of stroke. This study provides potential biomarkers to be examined in the human condition that could provide profound prognostic tools for stroke patients.

Translational Evaluation of Acid/Base and Electrolyte Alterations in Rodent Model of Focal Ischemia

BACKGROUND AND PURPOSE

Acid/base and electrolytes could provide clinically valuable information about cerebral infarct core and penumbra. We evaluated associations between acid/base and electrolyte changes and outcomes in 2 rat models of stroke, permanent, and transient middle cerebral artery occlusion.

METHODS

Three-month old Sprague-Dawley rats underwent permanent or transient middle cerebral artery occlusion. Pre- and post-middle cerebral artery occlusion venous samples for permanent and transient models provided pH, carbon dioxide, oxygen, glucose, and electrolyte values of ionized calcium, potassium, and sodium. Multiple regression determined predictors of infarct volume from these values, and Kaplan-Meier curve analyzed morality between permanent and transient middle cerebral artery occlusion models.

RESULTS

Analysis indicated significant differences in the blood gas and electrolytes between pre- to post-middle cerebral artery occlusion. A decrease in pH and sodium with increases in carbon dioxide, potassium, ionized calcium, and glucose changes were found in both middle cerebral artery occlusion models; while hematocrit and hemoglobin were significant in the transient model. pH and ionized calcium were predictors of infarct volume in the permanent model, as changes in pH and ionized calcium decreased, infarct volume increased.

CONCLUSIONS

There are acute changes in acid/base balance and electrolytes during stroke in transient and permanent rodent models. Additionally, we found pH and ionized calcium changes predicted stroke volume in the permanent middle cerebral artery occlusion model. These preliminary findings are novel, and warrant further exploration in human conditions.

A cohort study of relationship between serum calcium levels and cerebral microbleeds (CMBs) in ischemic stroke patients with AF and/or RHD

Calcium is an essential element for life and has cerebroprotective property in stroke patients. Low serum calcium levels were found to be related to large hematoma volumes in intracerebral hemorrhagic patients and hemorrhagic transformation in ischemic stroke patients after thrombolysis. However, their impact on hemorrhage-prone small vessel disease represented by cerebral microbleeds (CMBs) is uncertain. We aim to investigate whether low serum calcium levels are associated with presence and location of CMBs.Ischemic stroke patients with atrial fibrillation (AF) and/or rheumatic heart disease admitted to our hospital were consecutively and prospectively enrolled. Demographic and clinical information were collected and analyzed according to the occurrence and location of CMBs, and levels of serum calcium. We used logistic regression analysis to estimate the multivariable adjusted relationship between serum calcium levels and the presence or location of CMBs.Among the 67 patients (28 males; mean age, 67.3 years) in the final analysis, 39 (58.2%) were found to have CMBs. After adjustment for age, sex, smoking habits, drinking habits, and renal impairment, the presence of CMBs and deep CMBs was, respectively, 4.96- and 4.83-fold higher in patients with lower serum calcium levels (≤2.15 mmol/L) than in patients with higher serum calcium levels.Lower serum calcium levels (≤2.15 mmol/L) are independently associated with the presence of CMBs and deep CMBs in ischemic stroke patients with AF and/or rheumatic heart disease, which should be verified and extended in large cohorts, with other types of stroke patients and the general population.

Lower serum calcium level is associated with hemorrhagic transformation after thrombolysis

BACKGROUND AND PURPOSE

We aim to investigate whether lower admission serum calcium levels are associated with hemorrhagic transformation (HT) after intravenous thrombolysis (IVT).

METHODS

A total of 362 patients treated with IVT was divided into 4 quartiles based on admission serum calcium levels (Q1[<2.16], Q2[2.16, 2.23], Q3[2.24, 2.31], and Q4[>2.31] mmol/L). HT was classified as hemorrhagic infarction and parenchymal hemorrhage. Logistic regression was applied to assess the association between serum calcium levels and the incidence of HT.

RESULTS

Compared with Q4, HT was more common in Q1 (odds ratio, 2.580; 95% CI, [1.258-5.292]; P=0.010), Q2 (odds ratio, 2.382; 95% CI, [1.163-4.877]; P=0.018), and Q3 (odds ratio, 2.293; 95% CI, [1.133-4.637]; P=0.021). Hemorrhagic infarction was more common in Q1 (P=0.037), and Q2 (P=0.018), compared with Q4, and parenchymal hemorrhage was more common in Q1 (P=0.029) than Q4.

CONCLUSIONS

Lower admission serum calcium level is independently associated with HT after IVT, and this hypothesis needs larger confirmatory trials.

Elevated calcium after acute ischemic stroke: association with a poor short-term outcome and long-term mortality

BACKGROUND AND PURPOSE

An elevated intracellular calcium level is known to be a major initiator and activator of ischemic cell death pathway; however, in recent studies, elevated serum calcium levels have been associated with better clinical outcomes and smaller cerebral infarct volumes. The pathophysiological role played by calcium in ischemic stroke is largely unknown.

METHODS

Acute stroke patients from a prospective stroke registry, consecutively admitted during October 2002-September 2008, were included. Significant associations between the modified Rankin scale distribution at discharge and serum calcium or albumin-corrected calcium were identified using ordinal logistic regression analysis. Cox proportional hazard models were used for survival analysis.

RESULTS

Mean serum calcium and albumin-corrected calcium levels of the 1,915 participants on admission were 8.97±0.58 mg/dL and 9.07±0.49 mg/dL, respectively. Second [adjusted odds ratio 1.32 (95% confidence interval 1.07-1.61)] and third [1.24 (1.01-1.53)] tertiles of serum calcium level and the third [1.24 (1.01-1.53)] tertile of albumin-corrected calcium level were found to be independent risk factors for a poor discharge outcome. Significant relationships were observed with serum calcium [1.19 (1.03-1.38)] and albumin-corrected calcium [1.21(1.01-1.44)] as linear variables. However, only albumin-corrected calcium was associated with long-term mortality, third tertile [adjusted hazard ratio 1.40 (1.07-1.83)], and increase by 1 mg/dL [1.46 (1.16-1.84)].

CONCLUSIONS

Elevated albumin-corrected serum calcium levels are associated with a poorer short-term outcome and greater risk of long-term mortality after acute ischemic stroke.

Mobilization of endogenous bone marrow derived endothelial progenitor cells and therapeutic potential of parathyroid hormone after ischemic stroke in mice

Stroke is a major neurovascular disorder threatening human life and health. Very limited clinical treatments are currently available for stroke patients. Stem cell transplantation has shown promising potential as a regenerative treatment after ischemic stroke. The present investigation explores a new concept of mobilizing endogenous stem cells/progenitor cells from the bone marrow using a parathyroid hormone (PTH) therapy after ischemic stroke in adult mice. PTH 1-34 (80 µg/kg, i.p.) was administered 1 hour after focal ischemia and then daily for 6 consecutive days. After 6 days of PTH treatment, there was a significant increase in bone marrow derived CD-34/Fetal liver kinase-1 (Flk-1) positive endothelial progenitor cells (EPCs) in the peripheral blood. PTH treatment significantly increased the expression of trophic/regenerative factors including VEGF, SDF-1, BDNF and Tie-1 in the brain peri-infarct region. Angiogenesis, assessed by co-labeled Glut-1 and BrdU vessels, was significantly increased in PTH-treated ischemic brain compared to vehicle controls. PTH treatment also promoted neuroblast migration from the subventricular zone (SVZ) and increased the number of newly formed neurons in the peri-infarct cortex. PTH-treated mice showed significantly better sensorimotor functional recovery compared to stroke controls. Our data suggests that PTH therapy improves endogenous repair mechanisms after ischemic stroke with functional benefits. Mobilizing endogenous bone marrow-derived stem cells/progenitor cells using PTH and other mobilizers appears an effective and feasible regenerative treatment after ischemic stroke.

Evolving role of biomarkers in acute cerebrovascular disease

The development of a clinically validated biomarker of acute cerebral ischemia would have the potential to facilitate the use of time-sensitive reperfusion strategies, allow for individualization of patient care by predicting relative risk of hemorrhage and volume of penumbral tissue, and add valuable prognostic information for patients presenting with acute stroke. Additionally, a stroke biomarker might benefit early stage clinical research by serving as a surrogate measure of ischemic injury. Although at present there are no clinically validated biomarkers of acute stroke, previous studies have focused on markers associated with different components of the ischemic cascade, including microglial activation, inflammation, oxidative stress, neuronal injury, hemostasis, and endothelial dysfunction. Evolving technologies have provided high throughput approaches to investigate potential gene and protein signatures, and methods to measure newly discovered markers of cell death and immune responses. Prior to defining the clinical utility of stroke biomarkers, it is critical to understand the inherent limitations of a biomarker-based approach and define its potential value for providing adjunctive diagnostic and prognostic information. The identification and validation of a clinically relevant biomarker, or panel of markers, of stroke will ultimately require incorporation of both stringent research design and assessment in the clinical context in which the marker will be used.

VISTA-Rehab: A Resource for Stroke Rehabilitation Trials

Background

Stroke rehabilitation is a complex intervention. Many factors influence the interaction between the patient and the elements of the intervention. Rehabilitation interventions are aimed at altering different domains of patient outcome including body functions, activity and participation. As a consequence, randomised clinical trials in this area are difficult to design. We developed an archive of stroke rehabilitation trials (VISTA-Rehab) to act as a resource to help trialists model and design future rehabilitation studies.

Methods

We developed specific eligibility criteria for the entry of stroke rehabilitation trials into the archive. We established a Steering Committee to oversee projects and publications and commenced the recruitment of rehabilitation trials into this resource.

Results

As of August 2009, VISTA-Rehab contains data from 23 stroke rehabilitation trials (>3400 patients). Demographic data, including age [median=73, interquartile range (63,79)], gender (male=53%) and initial dependency [median baseline Barthel index score=6, interquartile range ( 9 , 19 )], are available for all patients. Outcome measures include the modified Rankin Scale, Barthel Index, Rivermead Motor Assessment, Fugl-Meyer Assessment, General Health Questionnaire and Nottingham Extended Activities of Daily Living Scale.

Conclusion

VISTA-Rehab expands the Virtual International Stroke Trials Archive to include rehabilitation trials. Anonymised data can be used to examine questions specific to stroke rehabilitation and to generate novel hypotheses.

New approaches to neuroprotection in infant heart surgery

Advances in surgical techniques and perioperative management have led to dramatic improvements in outcomes for children with complex congenital heart disease (CHD). As the number of survivors continues to grow, clinicians are becoming increasingly aware that adverse neurodevelopmental outcomes after surgical repair of CHD represent a significant cause of morbidity, with widespread neuropsychologic deficits in as many as 50% of these children by the time they reach school age. Modifications of intraoperative management have yet to measurably impact long-term neurologic outcomes. However, exciting advances in our understanding of the underlying mechanisms of cellular injury and of the events that mediate endogenous cellular protection have provided a variety of new potential targets for the assessment, prevention, and treatment of neurologic injury in patients with CHD. In this review, we will discuss the unique challenges to developing neuroprotective strategies in children with CHD and consider how multisystem approaches to neuroprotection, such as ischemic preconditioning, will be the focus of ongoing efforts to develop new diagnostic tools and therapies. Although significant challenges remain, tremendous opportunity exists for the development of diagnostic and therapeutic interventions that can serve to limit neurologic injury and ultimately improve outcomes for infants and children with CHD.

Clinical application of blood biomarkers in cerebrovascular disease

Identifying a biomarker or panel of biomarkers of cerebral ischemia would have a major impact on the care of stroke patients by facilitating early management decisions and individualization of care. Biochemical surrogates of cerebral ischemia might also play an important role by identifying relevant pathways for novel therapeutic strategies and by facilitating early clinical trials in cerebrovascular disease. Serum biomarkers related to pathways of hemostasis, oxidation and inflammation, or alterations in glial and neuronal proteins, have been identified but none have been recommended for routine clinical use. This review describes the most promising biomarkers of cerebrovascular disease and the context and limitations in which they have been studied.