Biomarkers as predictors of outcome after cardiac arrest

Blood-Based Biomarkers for Neuroprognostication in Acute Brain Injury

Acute brain injury causes loss of functionality in patients that often is devastating. Predicting the degree of functional loss and overall prognosis requires a multifaceted approach to help patients, and more so their families, make important decisions regarding plans and goals of care. A variety of blood-based markers have been studied as one aspect of this determination. In this review, we discuss CNS-derived and systemic markers that have been studied for neuroprognostication purposes. We discuss the foundation of each protein, the conditions in which it has been studied, and how the literature has used these markers for interpretation. We also discuss challenges to using each marker in each section as well.

Association of B-Type Natriuretic Peptide Level with Clinical Outcome in Out-of-Hospital Cardiac Arrest in Emergency Department Patients

OBJECTIVES

B-type natriuretic peptide (BNP) is used for outcome assessment of various diseases. We designed this study to investigate whether BNP, which has been proven useful in the risk stratification of sudden cardiac arrest (SCA) of cardiac etiology, can also prove to be a valuable prognostic tool for SCA also included with non-cardiac etiology. In this study, we aim to investigate the relationship between measured BNP levels and clinical outcomes in SCA, regardless of the cause of SCA.

METHODS

This retrospective multicenter observational study was performed in two tertiary university hospitals and one general hospital between January 2015 and December 2020. The total number of SCA patients was 1625. The patients with out-of-hospital cardiac arrest over 19 years old and acquired laboratory data, including BNP at emergency department (ED) arrival, were included. BNP was measured during advanced Cardiovascular Life Support (ACLS). The exclusion criteria were age under 18 years, traumatic arrest, and without BNP.

RESULTS

The median BNP was 171.8 (range; 5-5000) pg/mL in the return of Spontaneous Circulation (ROSC), higher than No-ROSC (p = 0.007). The median BNP concentration was 99.7 (range; 5-3040.68) pg/mL in the survival to discharge, which was significantly lower than the death group (p = 0.012). The odds ratio of survival to discharge decreased proportionally to the BNP level. The odds ratio of neurologic outcome was not correlated with the BNP level.

CONCLUSION

In patients with SCA of all origins, low BNP concentration measured during ACLS correlated with an increased ratio of survival to discharge. However, BNP measured during ACLS was not found to be an independent factor.

Comparison of Prognostic Performance between Procalcitonin and Procalcitonin-to-Albumin Ratio in Post Cardiac Arrest Syndrome

(1) Background: Post-cardiac arrest syndrome (PCAS) is a type of global ischemic reperfusion injury that occurs after the return of spontaneous circulation (ROSC). The procalcitonin to albumin ratio (PAR) has been studied as an independent prognostic factor of various diseases. There are no previous studies of PAR in patients with PCAS. We assessed if PAR is more effective than procalcitonin (PCT) in predicting prognosis for patients with PCAS. (2) Methods: This retrospective cohort study included a total of 187 patients with PCAS after non-traumatic out-of-hospital cardiac arrest (OHCA) between January 2016 and December 2020. Multivariate logistic regression analysis was conducted to assess the association between PAR and PCAS prognosis. The predictive performance of PAR was compared with PCT via the receiver-operating characteristic (ROC) analysis and DeLong test.; (3) Results: PAR at 24 and 48 h after hospital admission were independently associated with one-month neurological outcome (OR: 1.167, 95% CI: 1.023-1.330; OR: 1.077, 95% CI: 1.012-1.146, p < 0.05). By ROC analysis, PAR showed better performance over PCT at 48 h after admission in predicting one-month CPC (0.763 vs. 0.772, p = 0.010). (4) Conclusions: Our findings suggest that PAR at 48 h after admission is more effective in predicting a one-month neurological outcome than PCT at 48 h after admission in patients with PCAS after OHCA.

Do Body Mass Index and Nutritional Risk Score 2002 Influence the In-Hospital Mortality of Patients Following Cardiac Arrest?

BACKGROUND

Contemporarily, cardiac arrest (CA) remains one of the leading causes of death. Poor nutritional status can increase the post-CA mortality risk. The aim of this study was to determine the relationship between body mass index (BMI) and Nutritional Risk Score 2002 (NRS 2002) results and in-hospital mortality in patients admitted to the intensive care unit (ICU) after in-hospital and out-of-hospital cardiac arrest.

METHODS

A retrospective study and analysis of medical records of 161 patients admitted to the ICU of the University Clinical Hospital in Wrocław (Wrocław, Poland) was conducted.

RESULTS

No significant differences in body mass index (BMI) and nutritional risk score (NRS 2002) values were observed between non-survivors and survivors. Non-survivors had significantly lower albumin concentration (p = 0.017) and total cholesterol (TC) (p = 0.015). In multivariate analysis BMI and NRS 2002 scores were not, per se, associated with the in-hospital mortality defined as the odds of death (Model 1: p: 0.700, 0.430; Model 2: p: 0.576, 0.599). Univariate analysis revealed significant associations between the hazard ratio (HR) and TG (p ≈ 0.017, HR: 0.23) and hsCRP (p ≈ 0.018, HR: 0.34). In multivariate analysis, mortality risk over time was influenced by higher scores in parameters such as BMI (HR = 0.164; p = 0.048) and hsCRP (HR = 1.006, p = 0.002).

CONCLUSIONS

BMI and NRS 2002, on their own (unconditionally - in the whole study group) did not alter the odds of mortality in patients admitted to the intensive care unit (ICU) after in-hospital and out-of-hospital cardiac arrest. The risk of in-hospital mortality (expressed as hazard ratio - the risk over the time period of the study) increased with an increase in BMI but not with NRS 2002.

Rat model of asphyxia-induced cardiac arrest and resuscitation

Neurologic injury after cardiopulmonary resuscitation is the main cause of the low survival rate and poor quality of life among patients who have experienced cardiac arrest. In the United States, as the American Heart Association reported, emergency medical services respond to more than 347,000 adults and more than 7,000 children with out-of-hospital cardiac arrest each year. In-hospital cardiac arrest is estimated to occur in 9.7 per 1,000 adult cardiac arrests and 2.7 pediatric events per 1,000 hospitalizations. Yet the pathophysiological mechanisms of this injury remain unclear. Experimental animal models are valuable for exploring the etiologies and mechanisms of diseases and their interventions. In this review, we summarize how to establish a standardized rat model of asphyxia-induced cardiac arrest. There are four key focal areas: (1) selection of animal species; (2) factors to consider during modeling; (3) intervention management after return of spontaneous circulation; and (4) evaluation of neurologic function. The aim was to simplify a complex animal model, toward clarifying cardiac arrest pathophysiological processes. It also aimed to help standardize model establishment, toward facilitating experiment homogenization, convenient interexperimental comparisons, and translation of experimental results to clinical application.

Effect of Cytokine Adsorption on Survival and Circulatory Stabilization in Patients Receiving Extracorporeal Cardiopulmonary Resuscitation

Even after the introduction of extracorporeal cardiopulmonary resuscitation (ECPR), survival after cardiac arrest remains poor. Excess release of vasoactive cytokines may be a reason for cardiovascular instability and death after ECPR. Recently, an extracorporeal cytokine adsorption device (CytoSorb) to reduce elevated levels of circulating cytokines has been introduced. So far, it remains unclear if this device may improve survival and cardiovascular stabilization after ECPR. We report data from our investigator-initiated, single-center ECPR registry. We compared 23 ECPR patients treated with cytokine adsorption with a propensity-matched cohort of ECPR patients without cytokine adsorption. We analyzed survival, lactate clearance, vasopressor need, and fluid demand in both groups and performed between-group comparisons. Survival to discharge from intensive care unit (ICU) was 17.4% (4/23) in the cytokine adsorption group and 21.7% in the control group (5/23, P > 0.99). In both groups, we observed a decrease of serum-lactate, need for vasopressors, and fluid demand during the first 72 hours after ECPR. However, in direct comparison, we did not find significant between-group differences. In this retrospective registry study employing propensity score matching, cytokine adsorption in severely ill patients after ECPR was not associated with improved ICU survival nor a decrease of lactate, fluid, or vasopressor levels. Due to small case numbers and the retrospective design of the study, our results neither disprove nor confirm a clinically relevant treatment effect of cytokine adsorption. Results from larger trials, preferably randomized-controlled trials are required to better understand the clinical benefit of cytokine adsorption after ECPR.

Serum Copeptin Levels Predict the Return of Spontaneous Circulation and the Short-Term Prognosis of Patients with Out-of-Hospital Cardiac Arrest: A Randomized Control Study

Introduction:

Early and accurate prediction of survival to hospital discharge following resuscitation after cardiac arrest (CA) is a major challenge. Biomarkers can be used for early and accurate prediction of survival and prognosis following resuscitation after CA, but none of those identified so far are sufficient by themselves.

Hypothesis/Problem:

The goal of this study was to investigate the predictive power of the serum copeptin level for determining the return of spontaneous circulation (ROSC) and prognosis of patients with non-traumatic out-of-hospital cardiac arrest (OHCA) who underwent cardiopulmonary resuscitation (CPR).

Methods:

A total of 76 consecutive consenting adult patients who were diagnosed as non-traumatic OHCA and 63 age- and sex-matched healthy controls were enrolled. The patients were divided into two groups based on whether or not they had ROSC. The ROSC group was divided into two sub-groups according to whether death occurred within 24 hours or after 24 hours following ROSC. Serum copeptin, high-sensitivity cardiac troponin (hs-cTnI), creatine kinase-muscle/brain (CK-MB), glucose, and blood gas values were compared between the groups.

Results:

Serum copeptin levels were significantly higher in the patient group than control group (P <.001). Receiving operator characteristic analysis revealed a cut-off copeptin level of 27.29pmol/L, with 98.7% sensitivity and 100.0% specificity, for distinguishing patients from controls. Serum copeptin levels were significantly lower in the ROSC group than non-ROSC group (P = .018). Additionally, the mean serum hs-cTnI level was significantly higher in the ROSC group than non-ROSC group (P = .032). However, there were no significant differences in the mean serum glucose level and CK-MB levels or arterial blood gas levels between the ROSC and non-ROSC groups (all P >.05).

Ten (38.5%) of the patients died within the first 24 hours after ROSC, whereas 16 (61.5%) survived longer than 24 hours. Serum copeptin levels were significantly lower in patients who survived longer than 24 hours compared with those who died within the first 24 hours. Moreover, the mean CPR duration was significantly lower in patients surviving more than 24 hours compared with less than 24 hours.

Conclusion:

The serum copeptin level may serve as a guide in diagnostic decision making to predict ROSC in patients undergoing CPR and determining the short-term prognosis of patients with ROSC.

Biofluid Markers of Equine Neurological Disorders Reviewed From Human Perspectives

Neurological disorders (NDs) are often fatal to horses. Thus, symptoms of equine NDs commonly indicate euthanasia. Current diagnostic approaches for equine NDs is based on clinical signs, differential diagnoses, analysis of cerebrospinal fluid (CSF), assessment of histopathological lesions, and imaging. However, advances in biofluid biomarkers in the diagnosis of human neurological diseases can potentially be applied to equine NDs. In this review, we described the established human blood and CSF neurobiomarkers that could potentially be used to diagnose equine NDs.

Effects of the duration of postresuscitation hyperoxic ventilation on neurological outcome and survival in an asphyxial cardiac arrest rat model

Cardiac arrest leads to sudden cessation of oxygen supply and cerebral hypoxia occurs when there is not sufficient oxygen supplied to the brain. Current Guidelines for adult cardiopulmonary resuscitation (CPR) and emergency cardiovascular care recommend the use of 100% oxygen during resuscitative efforts to maximize the probability of achieving the return of spontaneous circulation (ROSC). However, the optimal strategy for oxygen management after ROSC is still debatable. The aim of the present study was to evaluate the effects of the duration of post-resuscitation hyperoxic ventilation on neurological outcomes in asphyxial cardiac arrest rats treated with targeted temperature management (TTM). Asphyxia was induced by blocking the endotracheal tube in 80 adult male Sprague-Dawley rats. CPR begun after 7 min of untreated cardiac arrest. Animals were randomized to either the normoxic control under normothermia (NNC) group or to one of the 4 experimental groups (n = 16 each) immediately after ROSC: ventilated with 100% oxygen for 0 (O₂_0h), 1 (O₂_1h), 3 (O₂_3h), or 5 (O₂_5h) h and ventilated with room air thereafter under TTM. Physiological variables were recorded at baseline and during the 6 h postresuscitation monitoring period. Animals were closely observed for 96 h to assess neurologic recovery and survival. There were no significant differences in baseline measurements between groups, and all animals were successfully resuscitated. There were significant interactions between the duration of 100% oxygen administration and hemodynamics as well as, myocardial and cerebral injuries. Among all the durations of hyperoxic ventilation investigated, significantly lower neurological deficit scores and higher survival rates were observed in the O₂_3h group than in the NNC group. In conclusion, postresuscitation hyperoxic ventilation leads to improved PaO₂, PaCO₂, hemodynamic, myocardial and cerebral recovery in asphyxial cardiac arrest rats treated with TTM. However, the beneficial effects of high concentration-oxygen are duration dependent and ventilation with 100% oxygen during induced hypothermia contributes to improved neurological recovery and survival after 96 h.

Inhaling Hydrogen Ameliorates Early Postresuscitation EEG Characteristics in an Asphyxial Cardiac Arrest Rat Model

Background

Electroencephalography (EEG) is commonly used to assess the neurological prognosis of comatose patients after cardiac arrest (CA). However, the early prognostic accuracy of EEG may be affected by postresuscitation interventions. Recent animal studies found that hydrogen inhalation after CA greatly improved neurological outcomes by selectively neutralizing highly reactive oxidants, but the effect of hydrogen inhalation on EEG recovery and its prognostication value are still unclear. The present study investigated the effects of hydrogen inhalation on early postresuscitation EEG characteristics in an asphyxial CA rat model.

Methods

Cardiopulmonary resuscitation was initiated after 5 min of untreated CA in 40 adult female Sprague-Dawley rats. Animals were randomized for ventilation with 98% oxygen plus 2% hydrogen (H2) or 98% oxygen plus 2% nitrogen (Ctrl) under normothermia for 1 h. EEG characteristics were continuously recorded for 4 h, and the relationships between quantitative EEG characteristics and 96 h neurological outcomes were investigated.

Results

No differences in baseline and resuscitation data were observed between groups, but the survival rate was significantly higher in the H2 group than in the Ctrl group (90% vs. 40%, P < 0.01). Compared to the Ctrl group, the H2 group showed a shorter burst onset time (21.85 [20.00-23.38] vs. 25.70 [22.48-30.05], P < 0.01) and time to normal trace (169.83 [161.63-208.55] vs. 208.39 [186.29-248.80], P < 0.01). Additionally, the burst suppression ratio (0.66 ± 0.09 vs. 0.52 ± 0.17, P < 0.01) and weighted-permutation entropy (0.47 ± 0.16 vs. 0.34 ± 0.13, P < 0.01) were markedly higher in the H2 group. The areas under the receiver operating characteristic curves for the 4 EEG characteristics in predicting survival were 0.82, 0.84, 0.88, and 0.83, respectively.

Conclusions

In this asphyxial CA rat model, the improved postresuscitation EEG characteristics for animals treated with hydrogen are correlated with the better 96 h neurological outcome and predicted survival.

Hydrogen Inhalation is Superior to Mild Hypothermia for Improving Neurological Outcome and Survival in a Cardiac Arrest Model of Spontaneously Hypertensive Rat

BACKGROUND

Postcardiac arrest syndrome is the consequence of whole-body ischemia-reperfusion events that lead to multiple organ failure and eventually to death. Recent animal studies demonstrated that inhalation of hydrogen greatly mitigates postresuscitation myocardial dysfunction and brain injury. However, the influence of underlying heart disease on the efficacy of hydrogen is still unknown. In the present study, we investigated the effects of hydrogen inhalation on neurological outcome and survival in a cardiac arrest model of spontaneously hypertensive rat (SHR).

METHODS

Cardiopulmonary resuscitation was initiated after 4 min of untreated ventricular fibrillation in 40 SHRs. Immediately after successful resuscitation, animals were randomized to be ventilated with 98% oxygen and 2% nitrogen under normothermia (Ctrl), 2% nitrogen under hypothermia (TH), 2% hydrogen under normothermia (H2), or 2% hydrogen under hypothermia (H2+TH) for 2 h. Hypothermia was maintained at 33°C for 2 h. Animals were observed up to 96 h for assessment of survival and neurologic recovery.

RESULTS

No statistical differences in baseline measurements were observed among groups and all the animals were successfully resuscitated. Compared with Ctrl, serum cardiac troponin T measured at 5 h and myocardial damage score measured at 96 h after resuscitation were markedly reduced in H2, TH, and H2+TH groups. Compared with Ctrl and TH, astroglial protein S100 beta measured during the earlier postresuscitation period, and neurological deficit score and neuronal damage score measured at 96 h were considerably lower in both H2 and H2+TH groups. Ninety-six hours survival rates were significantly higher in the H2 (80.0%) and H2+TH (90.0%) groups than TH (30.0%) and to Ctrl (30.0%).

CONCLUSIONS

Hydrogen inhaling was superior to mild hypothermia for improving neurological outcome and survival in cardiac arrest and resuscitation model of systemic hypertension rats.

Determination of Cut-off Serum Values for Resistin and S100B Protein in Patients Who Survived a Cardiac Arrest

Introduction

In an attempt to identify patients who have successfully survived a resuscitated cardiac arrest (CA), attention is drawn to resistin and S100B protein, two biomarkers that have been studied in relation to CA.

Aim

The study aimed to identify the potential cut-off serum values for resistin and S100B in patients who had CA, compared to healthy volunteers, given that, currently, none of the markers have normal and pathological reference range limits for human assay levels related to this pathology.

Materials and Methods

Forty patients, resuscitated after out-of-hospital CA and forty healthy controls, were included in the study. All patients were followed up for seventy-two hours after CA or until death. Blood samples for biomarkers were collected on admission to the ED (0-time interval) and at 6, 12, 24, 48 and 72 hours following resuscitation. Only one blood sample was collected from the controls. The serum concentrations of biomarkers were measured.

Results

For each time interval, median serum levels of resistin and S100 B were ​ significantly higher in patients with CA compared to healthy controls. The cut-of value for resistin in patients with CA, at the 12-hours versus controls, was > 8.2 ng/ml. The cut-of value for S100B in patients with CA versus controls recorded at 6 hours, was > 11.6 pg/ml.

Conclusion

Serum levels of resistin and S100B are higher among resuscitated CA patients compared to controls.

[Biomarkers after resuscitation : Relevance in daily clinical practice for prognosis estimation and definition of therapeutic goals]

BACKGROUND

The assessment of the neurological prognosis after cardiac arrest should be made using a multimodal approach involving clinical, physical and laboratory findings. Here, biomarkers are of high importance. The reliable prognostication has far-reaching consequences for the patient on the further course of therapy and rehabilitation.

OBJECTIVES

Which biomarkers help in prognosis estimation and therapy target definition and are currently used in daily clinical practice?

MATERIALS AND METHODS

Presentation of the multimodal approach for prognosis generation in patients after resuscitation with hypoxic-ischemic encephalopathy with special consideration and discussion of various biomarkers.

RESULTS AND CONCLUSION

Neuron-specific enolase (NSE) is the best-established predictive biomarker in patients with hypoxic-ischemic encephalopathy after cardiac arrest. In combination with other methods (clinical examination, physical testing) and considering possible interfering factors (hemolysis, tumor diseases), NSE is used after 48-72 h with a cutoff value of 90 ng/ml. Most other biomarkers have so far only been studied in smaller groups or individual studies and thus cannot currently be routinely used outside of studies.

Neutrophil-lymphocyte ratio: A prognostic tool in patients with in-hospital cardiac arrest

BACKGROUND

In-hospital cardiac arrest (IHCA) portends a poor prognosis and survival to discharge rate. Prognostic markers such as interleukin-6, S-100 protein and high sensitivity C reactive protein have been studied as predictors of adverse outcomes after return of spontaneous circulation (ROSC); however; these variables are not routine laboratory tests and incur additional cost making them difficult to incorporate and less attractive in assessing patient’s prognosis. The neutrophil-lymphocyte ratio (NLR) is a marker of adverse prognosis for many cardiovascular conditions and certain types of cancers and sepsis. We hypothesize that an elevated NLR is associated with poor outcomes including mortality at discharge in patients with IHCA.

AIM

To determine the prognostic significance of NLR in patients suffering IHCA who achieve ROSC.

METHODS

A retrospective study was performed on all patients who had IHCA with the advanced cardiac life support protocol administered in a large urban community United States hospital over a one-year period. Patients were divided into two groups based on their NLR value (NLR < 4.5 or NLR ≥ 4.5). This cutpoint was derived from receiving operator characteristic curve analysis (area under the curve = 0.66) and provided 73% positive predictive value, 82% sensitivity and 42% specificity for predicting in-hospital death after IHCA. The primary outcome was death or discharge at 30 d, whichever came first.

RESULTS

We reviewed 153 patients with a mean age of 66.1 ± 16.3 years; 48% were female. In-hospital mortality occurred in 65%. The median NLR in survivors was 4.9 (range 0.6-46.5) compared with 8.9 (0.28-96) in non-survivors (P = 0.001). A multivariable logistic regression model demonstrated that an NLR above 4.55 [odds ratio (OR) = 5.20, confidence interval (CI): 1.5-18.3, P = 0.01], older age (OR = 1.03, CI: 1.00-1.07, P = 0.05), and elevated serum lactate level (OR = 1.20, CI: 1.03-1.40, P = 0.02) were independent predictors of death.

CONCLUSION

An NLR ≥ 4.5 may be a useful marker of increased risk of death in patients with IHCA.

Resistin-Can it be a new early marker for prognosis in patients who survive after a cardiac arrest? A pilot study

AIM

The aim of our study was to evaluate the potential role of resistin in estimating the 30 days prognosis in patients with hypoxic-ischemic organ injury who survived after a cardiac arrest (CA).

MATERIALS AND METHODS

The study included 40 patients resuscitated after a non-traumatic out-of-hospital CA admitted in Emergency Department (ED). All patients were followed for 30 days after CA or until death. Clinical data on admission were recorded. Blood samples were collected on admission in ED (0-time interval), and at 6, 12, 24, 48- and 72-hours following resuscitation. Serum concentrations of resistin, S100B and neuron specific enolase (NSE) were measured. Several predictive scores for the mortality at 30 days were created with logistic regressions.

RESULTS

At each time interval, median serum levels of resistin and S100 B were significantly higher in non-survivors compared to survivors. For NSE, plasma levels were significantly lower in survivors as compared to non-survivors at 48 and 72 hours, respectively. Accurate predictive scores for 30-days mortality were the ones which included the values of resistin and S100B measured at 12 hours after admittance [AUC 0.938 (0.813-0.989), sensitivity 85.71% (67.3%- 96%), specificity 91.67% (61.5%'99.8%), p<0.001], which included the values of all three markers measured at 12 hours after admittance [AUC 0.955 (0.839-0.995), sensitivity 82.14% (63.1%'93.9%), specificity 100.00% (73.5%'100.0%), p<0.001] and the that included the values of resistin and S-100B at 6 hours together with serum lactate on admission [AUC = 0.994 (0.901-1.0), sensitivity 96.4% (81.7%'99.9%), specificity 100.00% (73.5%'100.0%), p<0.001].

CONCLUSION

In our study, serum levels of resistin or a combination of resistin with S-100B or resistin with S-100B and lactate, were highly predictive for 30 days mortality in resuscitated patients after CA. Further studies on large number of patients are needed to confirm our data.

Repetitive anodal transcranial direct current stimulation improves neurological outcome and survival in a ventricular fibrillation cardiac arrest rat model

BACKGROUND

Transcranial direct current stimulation (tDCS) modulates neuronal activity and is a potential therapeutic tool for many neurological diseases. However, its beneficial effects on post cardiac arrest syndrome remains uncertain.

OBJECTIVE/HYPOTHESIS

We investigated the effects of repetitive anodal tDCS on neurological outcome and survival in a ventricular fibrillation (VF) cardiac arrest rat model.

METHODS

Cardiopulmonary resuscitation was initiated after 6 min of VF in 36 Sprague-Dawley rats. The animals were randomized into three groups immediately after resuscitation (n = 12 each): no-treatment control (NTC) group, targeted temperature management (TTM) group, and tDCS group. For tDCS, 1 mA anodal tDCS was applied on the dorsal scalp for 0.5 h. The stimulation was repeated for four sessions with 1-h resting interval under normothermia. Post-resuscitation hemodynamic, cerebral, and myocardial injuries, 96-h neurological outcome, and survival were evaluated.

RESULTS

Compared with the NTC group, post-resuscitation serum astroglial protein S100 beta and cardiac troponin T levels and 96-h neuronal and myocardial damage scores were markedly reduced in the tDCS and TTM groups. Myocardial ejection fraction, neurological deficit score, and 96-h survival rate were also significantly better for the tDCS and TTM groups. The period of post-resuscitation arrhythmia with hemodynamic instability was considerably shorter in the tDCS group, but no differences were observed in neurological outcome and survival between the tDCS and TTM groups.

CONCLUSIONS

In this cardiac arrest rat model, repeated anodal tDCS commenced after resuscitation improves 96-h neurological outcome and survival to an extent comparable to TTM by attenuating post-resuscitation cerebral and cardiac injuries.

Elevated Serum Glial Fibrillary Acidic Protein (GFAP) is Associated with Poor Functional Outcome After Cardiopulmonary Resuscitation

BACKGROUND

The neurological prognosis of patients after cardiopulmonary resuscitation (CPR) is difficult to assess. GFAP is an astrocytic intermediate filament protein released into bloodstream in case of cell death. We performed a prospective study aiming to compare the predictive potential of GFAP after resuscitation to the more widely used biomarker neuron-specific enolase (NSE).

METHODS

One hundred patients were included at 48 h (tolerance interval ±12 h) after cardiac arrest. A serum sample was collected immediately after study inclusion. We determined serum levels of GFAP and NSE by means of immunoassays. Primary outcome was the modified Glasgow outcome scale at 4 weeks. Values below four were considered as a poor functional outcome.

RESULTS

Median GFAP levels in poor outcome (n = 61) and good outcome (n = 39) patients were 0.03 μg/L (interquartile range 0.01-0.07 μg/L) and 0.02 μg/L (0.01-0.03 μg/L; p = 0.014), respectively. GFAP revealed a sensitivity of 60.7% and a specificity of 66.7% to predict a poor functional outcome. All patients having a GFAP level >0.08 µg/L had a poor functional outcome. For NSE, sensitivity was 44.3% and specificity was 100.0% for predicting a poor outcome. Multivariate regression analysis revealed GFAP, NSE, and the Karnofsky index to be independent predictors of outcome.

CONCLUSIONS

The release patterns of GFAP and NSE after CPR show differences. GFAP levels above 0.08 µg/L were associated with a poor outcome in all cases, and patients with strongly elevated values (>3 µg/L) consistently had severe brain damage on brain imaging. Both biomarkers independently contribute to outcome prediction after CPR.

MicroRNAs as potential prognosticators of neurological outcome in out-of-hospital cardiac arrest patients

Out-of-hospital cardiac arrest survival rates have increased due to advancement in resuscitative measures, yet approximately 90% of survivors ultimately die or have severe neurologic dysfunction caused by ischemic injury. Currently, there are few early prognostic indicators of which patients have possibility of meaningful recovery. This leads to uncertainty for families and clinicians, as well as aggressive, invasive and expensive treatments despite medical futility. Several biomarkers investigated in traumatic brain injury have shown prognostication potential in ischemic brain injury. miRNAs, small noncoding RNAs responsible for gene regulation, have been studied in cardiovascular diseases, and have shown prognostication potential due to tissue specificity and stability in circulation. This review discusses available evidence on miRNAs prognosticating neurological outcomes after out-of-hospital cardiac arrest.

Prognostic value of neuron-specific enolase (NSE) for prediction of post-concussion symptoms following a mild traumatic brain injury: a systematic review

BACKGROUND

This systematic review aimed to determine the prognostic value of neuron-specific enolase (NSE) to predict post-concussion symptoms following mild traumatic brain injury (TBI).

METHODS

Seven databases were searched for studies evaluating the association between NSE levels and post-concussion symptoms assessed ≥ 3 months (persistent) or ≥ 7 days < 3 months (early) after mild TBI. Two researchers independently screened studies for inclusion, extracted data and appraised quality using the Quality in Prognostic Studies (QUIPS) tool.

RESULTS

The search strategy yielded a total of 23,298 citations from which 8 cohorts presented in 10 studies were included. Studies included between 45 and 141 patients (total 608 patients). The outcomes most frequently assessed were post-concussion syndrome (PCS, 12 assessments) and neuropsychological performance deficits (10 assessments). No association was found between an elevated NSE serum level and PCS. Only one study reported a statistically significant association between a higher NSE serum level and alteration of at least three cognitive domains at 2 weeks but this association was no longer significant at 6 weeks. Overall, risk of bias of the included studies was considered moderate.

CONCLUSIONS

Early NSE serum level is not a strong independent predictor of post-concussion symptoms following mild TBI.

Identification of novel biomarkers for prediction of neurological prognosis following cardiac arrest

Background

Early prognostication of neurological outcome in comatose patients after cardiac arrest (CA) is important for devising patient treatment strategies. However, there is still a lack of sensitive and specific biomarkers for easy identification of these patients. We evaluated whether molecular signatures from blood of CA patients might help to improve the prediction of neurological outcome.

Methods

We examined 22 comatose patients resuscitated after CA and obtained peripheral blood samples 48 hours after CA. To identify novel blood biomarkers, we aimed to measure neurological outcomes according to the Cerebral Performance Category (CPC) score at 6 months after CA and to determine blood transcriptome-based molecular signature of poor neurological outcome group.

Results

According to the CPC score, 10 patients exhibited a CPC score of one and 12 patients, a CPC score four to five. Blood transcriptomics revealed differently expressed profiles between the good outcome group and poor outcome group. A total of 150 genes were down-regulated and 237 genes were up-regulated in the poor neurological outcome group compared with good outcome group. From the blood transcriptome-based signatures, we identified that MAPK3, BCL2 and AKT1 were more specific and sensitive diagnostic biomarkers in poor neurological outcome with an area under the curve of 0.867 (p<0.0001), 0.800 (p=0.003), and 0.767 (p=0.016) respectively.

Conclusions

We identify three biomarkers as potential predictors of neurological outcome following CA. Further assessment of the prognostic value of transcriptomic analysis in larger cohorts of CA patients is needed.

Prognostic utility of neuroinjury biomarkers in post out-of-hospital cardiac arrest (OHCA) patient management

Despite aggressive intervention, patients who survive an out-of-hospital cardiac arrest (OHCA) generally have very poor prognoses, with nationwide survival rates of approximately 10-20%. Approximately 90% of survivors will have moderate to severe neurological injury ranging from moderate cognitive impairment to brain death. Currently, few early prognostic indicators are considered reliable enough to support patients' families and clinicians' in their decisions regarding medical futility. Blood biomarkers of neurological injury after OHCA may be of prognostic value in these cases. When most bodily tissues are oxygen-deprived, cellular metabolism switches from aerobic to anaerobic respiration. Neurons are a notable exception, however, being dependent solely upon aerobic respiration. Thus, after several minutes without circulating oxygen, neurons sustain irreversible damage, and certain measurable biomarkers are released into the circulation. Prior studies have demonstrated value in blood biomarkers in prediction of survival and neurologic impairment after OHCA. We hypothesize that understanding peptide biomarker kinetics in the early return of spontaneous circulation (ROSC) period, especially in the setting of refractory cardiac arrest, may assist clinicians in determining prognosis earlier in acute resuscitation. Specifically, during and after immediate resuscitation and return of ROSC, clinicians and families face a series of important questions regarding patient prognosis, futility of care and allocation of scarce resources such as the early initiation of extracorporeal cardiopulmonary resuscitation (ECPR). The ability to provide early prognostic information in this setting is highly valuable. Currently available, as well as potential biomarkers that could be good candidates in prognostication of neurological outcomes after OHCA or in the setting of refractory cardiac arrest will be reviewed and discussed.

Neuroprognostication after adult cardiac arrest treated with targeted temperature management: task force for Belgian recommendations

The prognosis of patients who are admitted to the hospital after cardiac arrest often relies on neurological examination, which could be significantly influenced by the use of sedative drugs or the implementation of targeted temperature management. The need for early and accurate prognostication is crucial as up to 15-20% of patients could be considered as having a poor outcome and may undergo withdrawal of life-sustaining therapies while a complete neurological recovery is still possible. As current practice in Belgium is still based on a very early assessment of neurological function in these patients, the Belgian Society of Intensive Care Medicine created a multidisciplinary Task Force to provide an optimal approach for monitoring and refine prognosis of CA survivors. This Task Force underlined the importance to use a multimodal approach using several additional tools (e.g., electrophysiological tests, neuroimaging, biomarkers) and to refer cases with uncertain prognosis to specialized centers to better evaluate the extent of brain injury in these patients.

The Extent of Myocardial Injury During Prolonged Targeted Temperature Management After Out-of-Hospital Cardiac Arrest

AIM

The aim of this study is to evaluate the extent of myocardial injury by cardiac biomarkers during prolonged targeted temperature management of 24 hours vs 48 hours after out-of-hospital cardiac arrest.

METHODS

This randomized Scandinavian multicenter study compares the extent of myocardial injury quantified by area under the curve (AUC) of cardiac biomarkers during prolonged targeted temperature management at 33°C ± 1°C of 24 hours and 48 hours, respectively. Through a period of 2.5 years, 161 comatose out-of-hospital cardiac arrest patients were randomized to targeted temperature management for 24 hours (n = 77) or 48 hours (n = 84). The AUC was calculated using both high-sensitivity cardiac troponin T (hs-cTnT_AUC) and creatine kinase-myocardial band (CK-MB_AUC) that were based upon measurements of these biomarkers every 6 hours upon admission until 96 hours after reaching target temperature.

RESULTS

The median hs-cTnT_AUC of 33,827 ng/L/h (interquartile range [IQR] 11,366-117,690) of targeted temperature management at 24 hours did not differ significantly from that of 28,973 ng/L/h (IQR 10,656-163,655) at 48 hours. In contrast, the median CK-MB_AUC of 1829 μg/L/h (IQR 800-6799) during targeted temperature management at 24 hours was significantly lower than that of 2428 μg/L/h (IQR 1163-10,906) within targeted temperature management at 48 hours, P <.05.

CONCLUSION

This study of comatose out-of-hospital cardiac arrest survivors showed no difference between the extents of myocardial injury estimated by hs-cTnT_AUC of prolonged targeted temperature management of 48 hours vs 24 hours, although the CK-MB_AUC was significantly higher during 48 hours vs 24 hours. Hence, it seems unlikely that the duration of targeted temperature management has a beneficial effect on the extent of myocardial injury after out-of-hospital cardiac arrest, and may even have a worsening effect.

Predicting the outcomes for out-of-hospital cardiac arrest patients using multiple biomarkers and suspension microarray assays

Predicting the prognosis for cardiac arrest is still challenging. Combining biomarkers from diverse pathophysiological pathways may provide reliable indicators for the severity of injury and predictors of long-term outcomes. We investigated the feasibility of using a multimarker strategy with key independent biomarkers to improve the prediction of outcomes in cardiac arrest. Adult out-of-hospital cardiac arrest patients with sustained return of spontaneous circulation were prospectively enrolled in this study. Blood samples were taken at 2 and 24 hours after cardiac arrest. Suspension microarray assays were used to test 21 different biomarkers. A total of 99 patients were enrolled, 45 of whom survived to hospital discharge. We identified 11 biomarkers that, when combined with clinical variables and factors of APACHE II score and history of arrhythmia, were independent determinants for outcome of in-hospital mortality (concordance = 0.9249, standard error = 0.0779). Three biomarkers combined with APACHE II and age were independent determinants for favorable neurological outcome at hospital discharge (area under the receiver-operator characteristic curve, 0.938; 95% confidence interval, 0.854 ~ 1.0). In conclusion, a systemic multiple biomarker approach using suspension microarray assays can identify independent predictors and model the outcomes of cardiac arrest patients during the post-cardiac arrest period.

Increased platelet mitochondrial respiration after cardiac arrest and resuscitation as a potential peripheral biosignature of cerebral bioenergetic dysfunction

Cardiac arrest (CA) results in a sepsis-like syndrome with activation of the innate immune system and increased mitochondrial bioenergetics.

OBJECTIVE

To determine if platelet mitochondrial respiration increases following CA in a porcine pediatric model of asphyxia-associated ventricular fibrillation (VF) CA, and if this readily obtained biomarker is associated with decreased brain mitochondrial respiration. CA protocol: 7 min of asphyxia, followed by VF, protocolized titration of compression depth to systolic blood pressure of 90 mmHg and vasopressor administration to a coronary perfusion pressure greater than 20 mmHg.

PRIMARY OUTCOME

platelet integrated mitochondrial electron transport system (ETS) function evaluated pre- and post-CA/ROSC four hours after return of spontaneous circulation (ROSC). Secondary outcome: correlation of platelet mitochondrial bioenergetics to cerebral bioenergetic function. Platelet maximal oxidative phosphorylation (OXPHOSCI+CII), P < 0.02, and maximal respiratory capacity (ETSCI+CII), P < 0.04, were both significantly increased compared to pre-arrest values. This was primarily due to a significant increase in succinate-supported respiration through Complex II (OXPHOSCII, P < 0.02 and ETSCII, P < 0.03). Higher respiration was not due to uncoupling, as the LEAKCI + CII respiration (mitochondrial respiration independent of ATP-production) was unchanged after CA/ROSC. Larger increases in platelet mitochondrial respiratory control ratio (RCR) compared to pre-CA RCR were significantly correlated with lower RCRs in the cortex (P < 0.03) and hippocampus (P < 0.04) compared to sham respiration. Platelet mitochondrial respiration is significantly increased four hours after ROSC. Future studies will identify mechanistic relationships between this serum biomarker and altered cerebral bioenergetics function following cardiac arrest.

Cardiovascular Collapse Associated With Irreversible Cardiomyopathy, Chronic Renal Failure, and Hypertension During Routine Dental Care

Patients with multiple comorbid conditions visit the dental office every day, and although rare, complications from their conditions may occur during treatment. A case is presented of a 65-year-old African American woman with a history of severe cardiovascular disease, renal disease, and a reported local anesthetic allergy who experienced complete cardiovascular collapse during routine dental treatment from which she was successfully resuscitated. Treating clinicians should recognize the emerging symptoms and be proficient with a basic and advanced cardiac life support protocol to care for their patients safely and effectively until they can be transported to more advanced care facilities.

Cardiac Arrest Disrupts Caspase-1 and Patterns of Inflammatory Mediators Differently in Skin and Muscle Following Localized Tissue Injury in Rats: Insights from Data-Driven Modeling

BACKGROUND

Trauma often cooccurs with cardiac arrest and hemorrhagic shock. Skin and muscle injuries often lead to significant inflammation in the affected tissue. The primary mechanism by which inflammation is initiated, sustained, and terminated is cytokine-mediated immune signaling, but this signaling can be altered by cardiac arrest. The complexity and context sensitivity of immune signaling in general has stymied a clear understanding of these signaling dynamics.

METHODOLOGY/PRINCIPAL FINDINGS

We hypothesized that advanced numerical and biological function analysis methods would help elucidate the inflammatory response to skin and muscle wounds in rats, both with and without concomitant shock. Based on the multiplexed analysis of inflammatory mediators, we discerned a differential interleukin (IL)-1α and IL-18 signature in skin vs. muscle, which was suggestive of inflammasome activation in the skin. Immunoblotting revealed caspase-1 activation in skin but not muscle. Notably, IL-1α and IL-18, along with caspase-1, were greatly elevated in the skin following cardiac arrest, consistent with differential inflammasome activation.

CONCLUSION/SIGNIFICANCE

Tissue-specific activation of caspase-1 and the NLRP3 inflammasome appear to be key factors in determining the type and severity of the inflammatory response to tissue injury, especially in the presence of severe shock, as suggested via data-driven modeling.

Impact of Admission Time on Treatment and Outcome of Stroke in Patients Admitted to Tertiary Care Hospital: A Pilot Study from Central India

INTRODUCTION

Admission of patients within window period has been linked with efficacy of treatment outcome and recovery. The present study examined the effects of early vs delayed admission on functional outcome of Acute Ischemic Stroke (AIS) as well as added value of stroke markers in such patients admitted to a tertiary care hospital in Central India.

MATERIALS AND METHODS

Hundred and four patients admitted to Neurology department of Central India Institute of Medical Sciences were grouped as early referrals (within 24 hour admission) and late referrals (after 24 hour admission) based on onset of symptoms and time of admission. Baseline data, throm bolysis eligibility, hospital and long term outcomes were determined in early and later referrals. Stroke markers NSE, S-100 ββ and ITIH4 peptides were also screened in patients who were further categorized as improved and expired /dependent during hospital outcome. Outcome of death /dependency in both groups was analysed using multivariate regression analysis. Kaplan-Meier analysis was performed to determine the rate of stroke-mortality in hospital and over 12 and 15 month period.

RESULTS

Hospital outcome indicated higher percentage (90%) of improved cases in early referrals as opposed to 79% observed in late referrals. Similarly, the ratio of dependency was slighter higher in late referrals (18%) as compared to early referral (6%) cases. The long term outcome at 12 and 18 months showed more or less similar ratio of death/dependency in early (23%, 9%) and late referrals (32%,24%) respectively. Multivariate analysis revealed no significant impact of risk confounders at long term and short term outcome in both groups. Analysis of stroke marker revealed better prognosis with significant association between ITIH4 peptides and NSE & S-100 ββ level with level of improvement in early referrals.

CONCLUSION

Early admission of AIS patients is associated with better hospital outcome. However admission time has no major impact on long term outcome in AIS patients. Moreover, stroke markers such ITIH4, can be used as a predictor of stroke outcome and may have prognostic importance in AIS cases in future.

NT-proBNP in cardiopulmonary resuscitated patients treated with mild therapeutic hypothermia is not independently associated with mortality: a retrospective observational study

Background

In spite of the introduction of mild therapeutic hypothermia (MTH), mortality rates remain high in patients with return of spontaneous circulation (ROSC) after cardiac arrest (CA). To date, no accurate and independent biomarker to predict survival in these patients exists. B-type natriuretic peptide (BNP) was found to provide both prognostic and diagnostic value in various cardiovascular diseases, including survival to hospital discharge in patients with ROSC. However, the biologically inactive counterpart of BNP, NT-proBNP, was found to be a more stable and accurate analyte. The current retrospective observational study investigates the value of NT-proBNP to predict 28-day mortality in post-CA patients treated with MTH, as well as the dynamics of NT-proBNP during MTH.

Methods

NT-proBNP levels were measured in post-CA patients cooled via cold intravenous saline infusion and water-circulating body wraps (Medi-Therm®, Gaymar). Plasma samples were obtained before cooling was started, at the start and end of the maintenance phase and at the end of rewarming.

Results

250 patients, admitted between 2009 and 2013, had NT-proBNP levels measured on ICU admission and were included for the evaluation of NT-proBNP as a prognostic marker. In the 28 days following ICU admission, 114 patients died (46%). Non-survivors had significantly higher NT-proBNP (median 1448 ng/l, IQR 366–4623 vs median 567 ng/1, IQR 148–1899; P < 0.001) levels on ICU admission. Unadjusted odds ratios for 28-day mortality were 1.7 (95% CI 0.8-3.5), 1.6 (0.8-3.3) and 3.6 (1.7-7.5) for increasing quartiles of NT-proBNP as compared to the lowest quartile. Adjusted odds ratios were 1.1 (95% CI 0.5-2.5), 1.1 (0.5-2.5) and 1.6 (0.7-3.8), respectively. A cut-off value of 834 ng/l achieved a sensitivity of 58% and a specificity of 58% to predict 28-day mortality. Of 113 patients, NT-proBNP values of each MTH phase were available and grouped in decreased or increased levels in time. Both decreases and increases of NT-proBNP values were observed during the MTH phases, but presence of either was not associated with outcome.

Conclusions

High NT-proBNP plasma concentrations on ICU admission are associated with high 28-day mortality in post-CA patients treated with MTH in a univariate analysis, but not in a multivariate analysis. Increases or decreases of NT-proBNP levels during MTH appear unrelated to 28 day mortality.

MicroRNAs: new biomarkers and therapeutic targets after cardiac arrest?

Despite advances in resuscitation medicine, including target temperature management as part of post-cardiac arrest care, many patients will have a poor neurological outcome, most often resulting in death. It is a commonly held belief that the ability to prognosticate outcome at an early stage after cardiac arrest would allow subsequent health care delivery to be tailored to individual patients. However, currently available predictive methods and biomarkers lack sufficient accuracy and therefore cannot be generally recommended in clinical practice. MicroRNAs have recently emerged as potential biomarkers of cardiovascular diseases. While the biomarker value of microRNAs for myocardial infarction or heart failure has been extensively studied, less attention has been devoted to their prognostic value after cardiac arrest. This review highlights the recent discoveries suggesting that microRNAs may be useful both to predict outcome and to treat patients after cardiac arrest.

Prognostic value of high-sensitivity troponin T levels in patients with ventricular arrhythmias and out-of-hospital cardiac arrest: data from the prospective FINNRESUSCI study

Introduction

Myocardial dysfunction is common after out-of-hospital cardiac arrest (OHCA) and high-sensitivity troponin T (hs-TnT) levels may provide incremental prognostic information to established risk indices.

Methods

A total of 155 patients with OHCA and a shockable rhythm (98% ventricular fibrillation; OHCA-VF/VT) had blood samples drawn within six hours of admission. Blood samples were also available after 24 hours, 48 hours, and 96 hours in subsets of patients. The endpoints of the study were hospital mortality and neurological status and mortality after one year.

Results

Admission hs-TnT levels were higher than the 99-percentile of the general population (14 ng/L) in all patients (range 18 to 17837 ng/L). Admission hs-TnT levels were associated with acute coronary artery occlusion, time to return of spontaneous circulation, heart failure, and renal function. Admission hs-TnT levels were higher in one-year non-survivors compared to survivors (median 747 (quartile 1 to 3, 206 to 1061) ng/L versus 345 (184 to 740) ng/L, P =0.023) and in patients with a poor versus a favorable neurological outcome (739 (191 to 1061) ng/L versus 334 (195 to 716) ng/L, P =0.028). However, hs-TnT measurements did not add prognostic information to established risk variables in multivariate analyses. hs-TnT levels measured during the hospitalization for OHCA-VF/VT correlated closely with admission levels (r ≥0.63) and were inferior to Simplified Acute Physiology Score II (SAPS II) scores for the prediction of events during follow-up. hs-TnT dynamics did not discriminate between survivors and non-survivors or between a poor versus a favorable neurological outcome.

Conclusion

hs-TnT levels are elevated in critically ill patients with OHCA-VF/VT, but do not improve risk prediction.

Hypothermia after cardiac arrest does not affect serum levels of neuron-specific enolase and protein S-100b

BACKGROUND

We investigated the brain-derived proteins neuron-specific enolase (NSE) and protein S-100b (S-100b) in survivors of cardiac arrest who had either received therapeutic hypothermia (TH) or had not.

METHODS

In a retrospective cohort study, we analysed serum levels of these two proteins over 5 days in 201 adult cardiac arrest survivors admitted to our intensive care unit between 2003 and 2010. These were all survivors that remained comatose and survived at least 48 h. Of these, 140 received therapeutic hypothermia (hypothermia group). The remainder received only standard therapy without hypothermia (normothermia group).

RESULTS

There was no difference in survival between the hypothermia and normothermia groups. At 4 weeks after arrest, 61 (43.6%) patients of the hypothermia group and 26 (42.6%) patients of the normothermia group were still alive with favourable to moderate neurological outcome (Cerebral Performance Category Scale 1-3). We observed no change in the mean serum levels of either protein between the two groups. Within each group, we found significantly higher serum levels of NSE and S-100b in patients with unfavourable neurological outcome (Cerebral Performance Category Scale 4 and 5) than in those with moderate to favourable outcome. Cut-off levels 3 days after cardiac arrest predicting an unfavourable outcome were >40 ng/ml for NSE [specificity 95.2%, Sensitivity 74.1%, areas under the curve (AUC):0.889], false positive rate 4 [confidence interval (CI): 0.0131-0.1175] and >1.03 μg/1 for S-100b (specificity 95.6%, Sensitivity 57.8%, AUC: 0.875) false positive rate 3 (CI: 0.0091-01218).

CONCLUSIONS

Additional application of TH was not associated with significant changes in serum levels of NSE and S-100b in comatose survivors of cardiac arrest, compared to those treated without TH.

Admission interleukin-6 is associated with post resuscitation organ dysfunction and predicts long-term neurological outcome after out-of-hospital ventricular fibrillation

AIM OF THE STUDY

To study plasma concentrations of interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP) and S-100B during intensive care after out-of-hospital cardiac arrest from ventricular fibrillation (OHCA-VF), and their associations with the duration of ischemia, organ dysfunction and long-term neurological outcome.

MATERIALS AND METHODS

A 12-month prospective observational multicentre study was conducted in 21 Finnish intensive care units in 2011. IL-6, hs-CRP and S-100B were measured at 0-6 h, 24 h, 48 h and 96 h after ICU admission. Associations with the time to return of spontaneous circulation (ROSC), sequential organ failure assessment (SOFA) scores divided into tertiles and 12-month cerebral performance category (CPC) were tested.

RESULTS

Of 186 OHCA-VF patients included in the study, 110 (59.1%) patients survived with good neurological outcome (CPC 1-2) 12 months after cardiac arrest. Admission plasma concentrations of IL-6 but not hs-CRP were higher with prolonged time to ROSC (p<0.001, 0.203, respectively), in patients with subsequent higher SOFA scores (p<0.001, 0.069) and poor long-term neurological outcome (CPC 3-5) (p<0.001, 0.315). S-100B concentrations over time were higher in patients with CPC of 3-5 (p<0.001). The area under the curve for prediction of poor 12-month outcome for admission levels was 0.711 IL-6, 0.663 for S-100B and 0.534 for hs-CRP. With multivariate logistic regression analysis only admission IL-6 (p=0.046, OR 1.006, 95% CI 1.000-1.011/ng/L) was an independent predictor of poor neurological outcome.

CONCLUSION

Admission high IL-6, but not hs-CRP or S-100B, is associated with extra-cerebral organ dysfunction and along with age and time to ROSC are independent predictors for 12-month poor neurologic outcome (CPC 3-5).

Prognostic relevance of plasma heart-type fatty acid binding protein after out-of-hospital cardiac arrest

OBJECTIVE

Heart-type fatty acid binding protein (H-FABP) is a tissue-specific protein which is rapidly released into the circulation when cardiomyocyte injury occurs. The aim of the study is to investigate the prognostic relevance of H-FABP for out-of-hospital cardiac arrest (OHCA) patients in the early post-cardiac arrest period.

DESIGN AND METHODS

This is a prospective cohort study enrolling non-traumatic resuscitated OHCA patients.

RESULTS

A total of 106 patients were enrolled. The H-FABP level at 24h was correlated to the duration from collapse to return of spontaneous circulation (p<0.001, R(2)=0.549). The outcomes of survival to discharge were worse in the patient group with the higher tertile of plasma H-FABP level at 24h after the event (p=0.011). Multivariate analysis demonstrated that the significant predictors for in-hospital mortality were APACHE II score (p=0.010), gender (p=0.025) and the tertiles of H-FABP at 24h with hazard ratios for the lowest, middle, and highest tertiles being 1.0, 1.157 (95% confidence interval 0.435-3.075, p=0.770), and 2.840 (95% confidence interval 1.137-7.092, p=0.025), respectively.

CONCLUSION

The plasma level of H-FABP at 24h after the event may be an early and independent factor associated with survival to discharge in OHCA patients.

CT-proAVP (copeptin), MR-proANP and Peroxiredoxin 4 after cardiac arrest: release profiles and correlation to outcome

BACKGROUND

Further characterization of the post-cardiac arrest syndrome (PCAS) is essential to better understand the mechanisms resulting in injury and death. We investigated serial serum concentrations of the stress hormone c-terminal provasopressin (CT-proAVP or copeptin), the cardiac biomarker MR-proANP and a biomarker of oxidation injury, Peroxiredoxin 4 (Prx4) in patients treated with mild hypothermia (MHT) after cardiac arrest, and studied their association to the PCAS and long-term outcome.

METHODS

Serum samples from cardiac arrest patients were collected serially: at admission, 2, 6, 12, 24, 36, 48 and 72 h after cardiac arrest. CT-proAVP, MR-proANP and Prx4 concentrations were determined and tested for association with two surrogate markers of PCAS (time to return of spontaneous circulation and circulation-SOFA score) and with cerebral performance category (CPC) at 6 months. Good outcome was defined as CPC 1 to 2.

RESULTS

Eighty-four patients were included. CT-proAVP, MR-proANP and Prx4 were early biomarkers with maximum concentrations soon after cardiac arrest and with a significant discriminatory ability between good and poor long-term outcome at most time points. CT-proAVP predicted a poor outcome with the highest accuracy, followed by MR-proANP and Prx4 (area under the receiving operating characteristics curve at 12 h of 0.85, 0.77 and 0.76 respectively). CT-proAVP and MR-proANP showed best correlation to the PCAS.

CONCLUSION

In 84 resuscitated patients receiving MHT after cardiac arrest, there is a significant difference in concentrations of CT-proAVP, MR-proANP and Prx4 between patients with good and poor outcome. CT-proAVP and MR-proANP have a significant correlation to surrogate markers of the PCAS.

The brain-enriched microRNA miR-124 in plasma predicts neurological outcome after cardiac arrest

Introduction

Early prognostication after successful cardiopulmonary resuscitation is difficult, and there is a need for novel methods to estimate the extent of brain injury and predict outcome. In this study, we evaluated the impact of the cardiac arrest syndrome on the plasma levels of selected tissue-specific microRNAs (miRNAs) and assessed their ability to prognosticate death and neurological disability.

Methods

We included 65 patients treated with hypothermia after cardiac arrest in the study. Blood samples were obtained at 24 hours and at 48 hours. For miRNA-screening purposes, custom quantitative polymerase chain reaction (qPCR) panels were first used. Thereafter individual miRNAs were assessed at 48 hours with qPCR. miRNAs that successfully predicted prognosis at 48 hours were further analysed at 24 hours. Outcomes were measured according to the Cerebral Performance Category (CPC) score at 6 months after cardiac arrest and stratified into good (CPC score 1 or 2) or poor (CPC scores 3 to 5).

Results

At 48 hours, miR-146a, miR-122, miR-208b, miR-21, miR-9 and miR-128 did not differ between the good and poor neurological outcome groups. In contrast, miR-124 was significantly elevated in patients with poor outcomes compared with those with favourable outcomes (P < 0.0001) at 24 hours and 48 hours after cardiac arrest. Analysis of receiver operating characteristic curves at 24 and 48 hours after cardiac arrest showed areas under the curve of 0.87 (95% confidence interval (CI) = 0.79 to 0.96) and 0.89 (95% CI = 0.80 to 0.97), respectively.

Conclusions

The brain-enriched miRNA miR-124 is a promising novel biomarker for prediction of neurological prognosis following cardiac arrest.

How to assess prognosis after cardiac arrest and therapeutic hypothermia

The prognosis of patients who are admitted in a comatose state following successful resuscitation after cardiac arrest remains uncertain. Although the introduction of therapeutic hypothermia (TH) and improvements in post-resuscitation care have significantly increased the number of patients who are discharged home with minimal brain damage, short-term assessment of neurological outcome remains a challenge. The need for early and accurate prognostic predictors is crucial, especially since sedation and TH may alter the neurological examination and delay the recovery of motor response for several days. The development of additional tools, including electrophysiological examinations (electroencephalography and somatosensory evoked potentials), neuroimaging and chemical biomarkers, may help to evaluate the extent of brain injury in these patients. Given the extensive literature existing on this topic and the confounding effects of TH on the strength of these tools in outcome prognostication after cardiac arrest, the aim of this narrative review is to provide a practical approach to post-anoxic brain injury when TH is used. We also discuss when and how these tools could be combined with the neurological examination in a multimodal approach to improve outcome prediction in this population.

Clinical review: Continuous and simplified electroencephalography to monitor brain recovery after cardiac arrest

There has been a dramatic change in hospital care of cardiac arrest survivors in recent years, including the use of target temperature management (hypothermia). Clinical signs of recovery or deterioration, which previously could be observed, are now concealed by sedation, analgesia, and muscle paralysis. Seizures are common after cardiac arrest, but few centers can offer high-quality electroencephalography (EEG) monitoring around the clock. This is due primarily to its complexity and lack of resources but also to uncertainty regarding the clinical value of monitoring EEG and of treating post-ischemic electrographic seizures. Thanks to technical advances in recent years, EEG monitoring has become more available. Large amounts of EEG data can be linked within a hospital or between neighboring hospitals for expert opinion. Continuous EEG (cEEG) monitoring provides dynamic information and can be used to assess the evolution of EEG patterns and to detect seizures. cEEG can be made more simple by reducing the number of electrodes and by adding trend analysis to the original EEG curves. In our version of simplified cEEG, we combine a reduced montage, displaying two channels of the original EEG, with amplitude-integrated EEG trend curves (aEEG). This is a convenient method to monitor cerebral function in comatose patients after cardiac arrest but has yet to be validated against the gold standard, a multichannel cEEG. We recently proposed a simplified system for interpreting EEG rhythms after cardiac arrest, defining four major EEG patterns. In this topical review, we will discuss cEEG to monitor brain function after cardiac arrest in general and how a simplified cEEG, with a reduced number of electrodes and trend analysis, may facilitate and improve care.