Predictive value of interleukin-6 in post-cardiac arrest patients treated with targeted temperature management at 33 °C or 36 °C

Canagliflozin Pretreatment Attenuates Myocardial Dysfunction and Improves Postcardiac Arrest Outcomes After Cardiac Arrest and Cardiopulmonary Resuscitation in Mice

OBJECTIVE

The SGLT2 inhibitor, canagliflozin, not only reduces glycemia in patients with type 2 diabetes but also exerts cardioprotective effects in individuals without diabetes. However, its potential beneficial effects in cardiac arrest have not been characterized. The purpose of this study was to examine the protective effect of canagliflozin pretreatment on postresuscitation-induced cardiac dysfunction in vivo.

METHODS

Male C57/BL6 mice were randomized to vehicle (sham and control) or canagliflozin treatment groups. All mice except for the sham-operated mice were subjected to potassium chloride-induced cardiac arrest followed by chest compressions and intravenous epinephrine for resuscitation. Canagliflozin therapy efficacies were evaluated by electrocardiogram, echocardiography, histological analysis, inflammatory response, serum markers of myocardial injury, protein phosphorylation analysis, and immunohistological assessment.

RESULTS

Canagliflozin-pretreated mice exhibited a higher survival rate (P < 0.05), a shorter return of spontaneous circulation (ROSC) time (P < 0.01) and a higher neurological score (P < 0.01 or P < 0.001) than control mice after resuscitation. Canagliflozin was effective at improving cardiac arrest and resuscitation-associated cardiac dysfunction, indicated by increased left ventricular ejection fraction and fractional shortening (P < 0.001). Canagliflozin reduced serum levels of LDH, CK-MB and α-HBDH, ameliorated systemic inflammatory response, and diminished the incidence of early resuscitation-induced arrhythmia. Notably, canagliflozin promoted phosphorylation of cardiac STAT-3 postresuscitation. Furthermore, pharmacological inhibition of STAT-3 by Ag490 blunted STAT-3 phosphorylation and abolished the cardioprotective actions of canagliflozin.

CONCLUSIONS

Canagliflozin offered a strong cardioprotective effect against cardiac arrest and resuscitation-induced cardiac dysfunction. This canagliflozin-induced cardioprotection is mediated by the STAT-3-dependent cell-survival signaling pathway.

Blood endothelium transition and phenotypic plasticity: A key regulator of integrity/permeability in response to ischemia

In the human body, the 1013 blood endothelial cells (ECs) which cover a surface of 500-700 m2 (Mai et al., 2013) are key players of tissue homeostasis, remodeling and regeneration. Blood vessel ECs play a major role in the regulation of metabolic and gaz exchanges, cell trafficking, blood coagulation, vascular tone, blood flow and fluid extravasation (also referred to as blood vascular permeability). ECs are heterogeneous in various capillary beds and have the exquisite capacity to cope with environmental changes by regulating their gene expression. Ischemia has major detrimental effects on the endothelium and ischemia-induced regulation of vascular integrity is of paramount importance for human health, as small amounts of fluid accumulation in the interstitium may be responsible for major effects on organ functions and patients outcome. In this review, we will here focus on the stimuli and the molecular mechanisms that control blood endothelium maintenance and phenotypic plasticity/transition involved in controlling blood capillary leakage that might open new avenues for therapeutic applications.

Wolf Creek XVII Part 8: Neuroprotection

Introduction

Post-cardiac arrest brain injury (PCABI) is the primary determinant of clinical outcomes for patients who achieve return of spontaneous circulation after cardiac arrest (CA). There are limited neuroprotective therapies available to mitigate the acute pathophysiology of PCABI.

Methods

Neuroprotection was one of six focus topics for the Wolf Creek XVII Conference held on June 14-17, 2023 in Ann Arbor, Michigan, USA. Conference invitees included international thought leaders and scientists in the field of CA resuscitation from academia and industry. Participants submitted via online survey knowledge gaps, barriers to translation, and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category that was debated, revised and ranked by all attendees to identify the top 5 for each category.

Results

Top 5 knowledge gaps included developing therapies for neuroprotection; improving understanding of the pathophysiology, mechanisms, and natural history of PCABI; deploying precision medicine approaches; optimizing resuscitation and CPR quality; and determining optimal timing for and duration of interventions. Top 5 barriers to translation included patient heterogeneity; nihilism & lack of knowledge about cardiac arrest; challenges with the translational pipeline; absence of mechanistic biomarkers; and inaccurate neuro-triage and neuroprognostication. Top 5 research priorities focused on translational research and trial optimization; addressing patient heterogeneity and individualized interventions; improving understanding of pathophysiology and mechanisms; developing mechanistic and outcome biomarkers across post-CA time course; and improving implementation of science and technology.

Conclusion

This overview can serve as a guide to transform the care and outcome of patients with PCABI. Addressing these topics has the potential to improve both research and clinical care in the field of neuroprotection for PCABI.

Recovery and Survival of Patients After Out-of-Hospital Cardiac Arrest: A Literature Review Showcasing the Big Picture of Intensive Care Unit-Related Factors

As an important public health issue, out-of-hospital cardiac arrest (OHCA) requires several stages of high quality medical care, both on-field and after hospital admission. Post-cardiac arrest shock can lead to severe neurological injury, resulting in poor recovery outcome and increased risk of death. These characteristics make this condition one of the most important issues to deal with in post-OHCA patients hospitalized in intensive care units (ICUs). Also, the majority of initial post-resuscitation survivors have underlying coronary diseases making revascularization procedure another crucial step in early management of these patients. Besides keeping myocardial blood flow at a satisfactory level, other tissues must not be neglected as well, and maintaining mean arterial pressure within optimal range is also preferable. All these procedures can be simplified to a certain level along with using targeted temperature management methods in order to decrease metabolic demands in ICU-hospitalized post-OHCA patients. Additionally, withdrawal of life-sustaining therapy as a controversial ethical topic is under constant re-evaluation due to its possible influence on overall mortality rates in patients initially surviving OHCA. Focusing on all of these important points in process of managing ICU patients is an imperative towards better survival and complete recovery rates.

The Effect of CytoSorb on Inflammatory Markers in Critically Ill Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

The effectiveness of CytoSorb at removing inflammatory mediators in critically ill patients is controversial.

DATA SOURCES

Electronic databases were searched from inception to May 2023.

STUDY SELECTION

Randomized controlled trials reporting the effects of CytoSorb therapy on inflammatory parameters in critically ill patients with hyperinflammatory conditions were included.

DATA EXTRACTION

Two authors screened articles for eligibility, extracted data, and assessed the risk of bias, conflicts of interest, and certainty of evidence (CoE). The primary outcome was interleukin (IL)-6 at 1 day after initiation of the therapy. Secondary outcomes included various inflammatory markers at 1, 2, 3, and 5 days and mortality. Data were pooled if at least three trials reported the outcome of interest. We conducted meta-analyses of the data using a random-effects model.

DATA SYNTHESIS

Seventeen trials ( n = 855) were included. Fourteen trials were judged to have notable concern about conflicts of interest. Seven trials were performed in medical ICU patients with hyperinflammatory conditions and 10 in complex cardiovascular surgery under cardiopulmonary bypass. Hemoadsorption with CytoSorb was not associated with lower IL-6 at 1 day (mean difference -5.98 [95% CI, -30.44 to 18.48] pg/mL), 2 days, 3 days, or 5 days after initiation of the treatment, as well as the concentration of procalcitionin. The levels of C-reactive protein were not lower with CytoSorb at 1, 2, and 3 days. The use of CytoSorb was associated with higher mortality at latest follow-up (relative risk = 1.22 [95% CI, 1.02-1.45]) and at 30 days. CoE ranged from low to very low.

CONCLUSIONS

The use of CytoSorb hemoadsorption in a mixed population of critically ill patients with hyperinflammatory conditions does not exhibit a consistent decrease in IL-6 and other inflammatory parameters within the first 5 days of treatment. The significant uncertainty surrounding these findings highlights the need for further investigations.

Prehospital high-dose methylprednisolone in resuscitated out-of-hospital cardiac arrest patients (STEROHCA): a randomized clinical trial

PURPOSE

Patients who are successfully resuscitated following out-of-hospital cardiac arrest (OHCA) are still at a high risk of neurological damage and death. Inflammation and brain injury are components of the post-cardiac arrest syndrome, and can be assessed by systemic interleukin 6 (IL-6) and neuron-specific enolase (NSE). Anti-inflammatory treatment with methylprednisolone may dampen inflammation, thereby improving outcome. This study aimed to determine if prehospital high-dose methylprednisolone could reduce IL-6 and NSE in comatose OHCA patients.

METHODS

The STEROHCA trial was a randomized, blinded, placebo-controlled, phase II prehospital trial performed at two cardiac arrest centers in Denmark. Resuscitated comatose patients with suspected cardiac etiology were randomly assigned 1:1 to a single intravenous injection of 250 mg methylprednisolone or placebo. The co-primary outcome was reduction of IL-6 and NSE-blood levels measured daily for 72 h from admission. The main secondary outcome was survival at 180 days follow-up.

RESULTS

We randomized 137 patients to methylprednisolone (n = 68) or placebo (n = 69). We found reduced IL-6 levels (p < 0.0001) in the intervention group, with median (interquartile range, IQR) levels at 24 h of 2.1 pg/ml (1.0; 7.1) and 30.7 pg/ml (14.2; 59) in the placebo group. We observed no difference between groups in NSE levels (p = 0.22), with levels at 48 h of 18.8 ug/L (14.4; 24.6) and 14.8 ug/L (11.2; 19.4) in the intervention and placebo group, respectively. In the intervention group, 51 (75%) patients survived and 44 (64%) in the placebo group.

CONCLUSION

Prehospital treatment with high-dose methylprednisolone to resuscitated comatose OHCA patients, resulted in reduced IL-6 levels after 24 h, but did not reduce NSE levels.

Soluble Urokinase-Type Plasminogen Activator Receptor in Comatose Survivors After Out-of-Hospital Cardiac Arrest Treated with Targeted Temperature Management

Exposure to whole-body ischemia/reperfusion after out-of-hospital cardiac arrest (OHCA) triggers a systemic inflammatory response where soluble urokinase plasminogen activator receptor (suPAR) is released. This study investigated serial levels of suPAR in differentiated target temperature management and the associations with mortality and 6-month neurological outcome. This is a single-center substudy of the randomized Targeted Temperature Management (TTM) for 24-hour versus 48-hour trial. In this analysis, we included 82 patients and measured serial levels of suPAR at 24, 48, and 72 hours after achievement of target temperature (32-34°C). We assessed all-cause mortality and neurological function evaluated by the Cerebral Performance Categories (CPC) at 6 months after OHCA. Levels of suPAR between TTH groups were evaluated in repeated measures mixed models. Mortality was assessed by the Kaplan-Meier method and serial measurements of suPAR (log2 transformed) were investigated by Cox proportional-hazards models. Good neurological outcome at 6 months was assessed by logistic regression analyses. Levels of suPAR were significantly different between TTH groups (pinteraction = 0.04) with the highest difference at 48 hours, 4.7 ng/mL (95% CI: 4.1-5.4 ng/mL) in the TTH24 group compared to 2.8 ng/mL (95% CI: 2.2-3.5 ng/mL) in the TTH48 group, p < 0.0001. Levels of suPAR above the median value were significantly associated with increased all-cause mortality at any time point (plog-rank<0.05). The interaction of suPAR levels and TTH group was not significant (pinteraction = NS). A twofold increase in levels of suPAR was significantly associated with a decreased odds ratio of a good neurological outcome in both unadjusted and adjusted analyses without interaction of TTH group (pinteraction = NS). Prolonged TTM of 48 hours versus 24 hours was associated with lower levels of suPAR. High levels of suPAR were associated with increased mortality and lower odds for good neurological outcome at 6 months with no significant interaction of TTH group.

Inflammatory response after out-of-hospital cardiac arrest-Impact on outcome and organ failure development

BACKGROUND

Post-cardiac arrest syndrome that occurs in out-of-hospital cardiac arrest (OHCA) patients is characterized by inflammatory response. We conducted a scoping review of current evidence regarding several inflammatory markers' usefulness for assessment of patient outcome and illness severity. We also discuss the proposed underlying mechanisms leading to inflammatory response after OHCA.

METHODS

We searched the MEDLINE, PubMed Central, Cochrane CENTRAL and Web of Science Core Collection databases with the following search terms: ("inflammation" OR "cytokines") AND "out-of-hospital cardiac arrest." Each inflammatory marker found was combined with "out-of-hospital cardiac arrest" using "AND" to find further relevant studies. We included original studies measuring inflammatory markers in adult OHCA patients that assessed their prognostic capabilities for mortality, neurological outcome, or organ failure severity.

RESULTS

Fifty-nine studies met the inclusion criteria, covering in total 65 different markers. Interleukin-6 (IL-6), procalcitonin (PCT) and C-reactive protein (CRP) were the most studied markers, and they were associated with poor outcomes in 13/15, 13/14 and 11/17 studies, respectively. Based on area under the receiver operating characteristic curve (AUC) value, the time point of best discriminatory capacity for poor outcome was ICU admission for IL-6 (median AUC 0.78, range 0.71-0.98) and day one after OHCA for PCT (median AUC 0.84, range 0.61-0.98). Seven studies reported AUCs for CRP (range 0.52-0.76) with no measurement time point being superior to others. The association of IL-6 and PCT with outcome appeared stronger in studies with more severely ill patients. Studies reported conflicting results regarding each marker's association with organ failure severity.

CONCLUSION

Inflammatory markers are potentially useful for early risk stratification after OHCA. PCT and IL-6 have moderate prognostic value during the first 24 h of the ICU stay. Predictive accuracy appears to be associated with the study overall event rate.

State of the art post-cardiac arrest care: evolution and future of post cardiac arrest care

Out-of-hospital cardiac arrest is a leading cause of mortality. In the pre-hospital setting, bystander response with cardiopulmonary resuscitation and the use of publicly available automated external defibrillators have been associated with improved survival. Early in-hospital treatment still focuses on emergency coronary angiography for selected patients. For patients remaining comatose, temperature control to avoid fever is still recommended, but former hypothermic targets have been abandoned. For patients without spontaneous awakening, the use of a multimodal prognostication model is key. After discharge, follow-up with screening for cognitive and emotional disabilities is recommended. There has been an incredible evolution of research on cardiac arrest. Two decades ago, the largest trials include a few hundred patients. Today, undergoing studies are planning to include 10-20 times as many patients, with improved methodology. This article describes the evolution and perspectives for the future in post-cardiac arrest care.

Hemadsorption in patients requiring V-A ECMO support: Comparison of Cytosorb versus Jafron HA330

BACKGROUND

ECMO support is associated with the development of a systemic hyper-inflammatory response, which may become quite significant and extreme in some cases. We hypothesize that Cytosorb or Jafron therapy may benefit patients on V-A ECMO in terms of levels of inflammatory markers such as IL-6, complications, and overall outcomes.

METHODS

We conducted a retrospective study of prospectively collected data in a single tertiary care center between January 2021 and April 2022. At the time of the analysis of this article, 20 patients on V-A ECMO had cytokine adsorption while on ECMO support: Cytosorb group (n = 10), Jafron group (n = 10). In 10 ECMO-supported patients cytokine adsorption was not used, this group served as a control group, which may be quite significant in some cases. Evaluation of the level of inflammatory markers (IL-1, 6, 8; CRP, Leukocyte, Lactate, PCT, NT-proBNP, TNF-α) was performed.

RESULTS

There was statistically significant longer CPB time, aortic cross-clamp time and ICU stay in cytokine adsorption groups than in the control group, but there were no differences between subgroups with different types of haemoadsorption used. Moreover, in the control group mortality rate was higher than in the cytokine adsorption groups (60% vs. 20%, p = 0.02). All patients had an elevation of inflammatory markers in the perioperative and immediate postoperative periods. After 72 h of intensive care, blood inflammation markers had a tendency to decline.

CONCLUSION

At the time of writing, hemadsorption in patients requiring V-A ECMO support represents a good therapeutic effect. This effect is permanent for the whole period of extracorporeal cytokine hemadsorption application for both CytoSorb and Jafron HA330 devices.

Modulation of inflammation by treatment with tocilizumab after out-of-hospital cardiac arrest and associations with clinical status, myocardial- and brain injury

AIM

To investigate how the inflammatory response after out-of-hospital cardiac arrest (OHCA) is modulated by blocking IL-6-mediated signalling with tocilizumab, and to relate induced changes to clinical status, myocardial- and brain injury.

METHODS

This is a preplanned substudy of the IMICA trial (ClinicalTrials.gov, NCT03863015). Upon admission 80 comatose OHCA patients were randomized to infusion of tocilizumab or placebo. Inflammation was characterized by a cytokine assay, CRP, and leukocyte differential count; myocardial injury by TnT and NT-proBNP; brain injury by neuron-specific enolase (NSE) and Neurofilament Light chain (NFL), while sequential organ assessment (SOFA) score and Vasoactive-Inotropic Score (VIS) represented overall clinical status.

RESULTS

Responses for IL-5, IL-6, IL-17, neutrophil as well as monocyte counts, and VIS were affected by tocilizumab treatment (all p < 0.05), while there was no effect on levels of NFL. IL-5 and IL-6 were substantially increased by tocilizumab, while IL-17 was lowered. Neutrophils and monocytes were lower at 24 and 48 hours, and VIS was lower at 24 hours, for the tocilizumab group compared to placebo. Multiple correlations were identified for markers of organ injury and clinical status versus inflammatory markers; this included correlations of neutrophils and monocytes with TnT, NSE, NFL, SOFA- and VIS score for the tocilizumab but not the placebo group. NT-proBNP, NFL and SOFA score correlated with CRP in both groups.

CONCLUSIONS

Treatment with tocilizumab after OHCA modulated the inflammatory response with notable increases for IL-5, IL-6, and decreases for neutrophils and monocytes, as well as reduced vasopressor and inotropy requirements.

Cytokine hemoadsorption with CytoSorb® in post-cardiac arrest syndrome, a pilot randomized controlled trial

BACKGROUND

Hemoadsorption (HA) might mitigate the systemic inflammatory response associated with post-cardiac arrest syndrome (PCAS) and improve outcomes. Here, we investigated the feasibility, safety and efficacy of HA with CytoSorb® in cardiac arrest (CA) survivors at risk of PCAS.

METHODS

In this pilot randomized controlled trial, we included patients admitted to our intensive care unit following CA and likely to develop PCAS: required norepinephrine (> 0.2 µg/kg/min), and/or had serum lactate > 6 mmol/l and/or a time-to-return of spontaneous circulation (ROSC) > 25 min. Those requiring ECMO or renal replacement therapy were excluded. Eligible patients were randomly allocated to either receive standard of care (SOC) or SOC plus HA. Hemoadsorption was performed as stand-alone therapy for 24 h, using CytoSorb® and regional heparin-protamine anticoagulation. We collected feasibility, safety and clinical data as well as serial plasma cytokines levels within 72 h of randomization.

RESULTS

We enrolled 21 patients, of whom 16 (76%) had out-of-hospital CA. Median (IQR) time-to-ROSC was 30 (20, 45) minutes. Ten were assigned to the HA group and 11 to the SOC group. Hemoadsorption was initiated in all patients allocated to the HA group within 18 (11, 23) h of ICU admission and conducted for a median duration of 21 (14, 24) h. The intervention was well tolerated except for a trend for a higher rate of aPTT elevation (5 (50%) vs 2 (18%) p = 0.18) and mild (100-150 G/L) thrombocytopenia at day 1 (5 (50%) vs 2 (18%) p = 0.18). Interleukin (IL)-6 plasma levels at randomization were low (< 100 pg/mL) in 10 (48%) patients and elevated (> 1000 pg/mL) in 6 (29%). The median relative reduction in IL-6 at 48 h was 75% (60, 94) in the HA group versus 5% (- 47, 70) in the SOC group (p = 0.06).

CONCLUSIONS

In CA survivors at risk of PCAS, HA was feasible, safe and was associated with a nonsignificant reduction in cytokine plasma levels. Future trials are needed to further define the role of HA after CA. Those studies should include cytokine assessment to enrich the study population.

TRIAL REGISTRATION

NCT03523039, registered 14 May 2018.

Conventional and Pro-Inflammatory Pathways of Fibrinolytic Activation in Non-Traumatic Hyperfibrinolysis

Hyperfibrinolysis (HF) frequently occurs after severe systemic hypoperfusion during major trauma and out-of-hospital cardiac arrest (OHCA). In trauma-induced HF, hypoperfusion, the activation of protein C (APC), and the release of tissue plasminogen activator (t-PA) have been identified as the driving elements of premature clot breakdown. The APC pathway also plays a role in inflammatory responses such as neutrophil extracellular trap formation (NETosis), which might contribute to lysis through cleavage of fibrin by neutrophil elastases. We investigated whether the APC and the plasminogen pathway were general drivers of HF, even in the absence of a traumatic incident. Additionally, we were interested in inflammatory activation such as the presence of NETs as potential contributing factors to HF. A total of 41 patients with OHCA were assigned to a HF and a non-HF group based on maximum lysis (ML) in thromboelastometry. Thrombin-antithrombin (TAT)-complex, soluble thrombomodulin (sTM), APC-PC inhibitor complex, t-PA, PAI-1, t-PA-PAI-1 complex, plasmin-antiplasmin (PAP), d-dimers, neutrophil elastase, histonylated DNA (hDNA) fragments, and interleukin-6 were assessed via immunoassays in the HF group vs. non-HF. APC-PC inhibitor complex is significantly higher in HF patients. Antigen levels of t-PA and PAI-1 do not differ between groups. However, t-PA activity is significantly higher and t-PA-PAI-1 complex significantly lower in the HF group. Consistent with these results, PAP and d-dimers are significantly elevated in HF. HDNA fragments and neutrophil elastase are not elevated in HF patients, but show a high level of correlation, suggesting NETosis occurs in OHCA as part of inflammatory activation and cellular decay. Just as in trauma, hypoperfusion, the activation of protein C, and the initiation of the plasminogen pathway of fibrinolysis manifest themselves in the HF of cardiac arrest. Despite features of NETosis being detectable in OHCA patients, early pro-inflammatory responses do not appear be associated with HF in cardiac arrest.

Contemporary Management of Concomitant Cardiac Arrest and Cardiogenic Shock Complicating Myocardial Infarction

Cardiogenic shock (CS) and cardiac arrest (CA) are the most life-threatening complications of acute myocardial infarction. Although there is a significant overlap in the pathophysiology with approximately half the patients with CS experiencing a CA and approximately two-thirds of patients with CA developing CS, comprehensive guideline recommendations for management of CA + CS are lacking. This paper summarizes the current evidence on the incidence, pathophysiology, and short- and long-term outcomes of patients with acute myocardial infarction complicated by concomitant CA + CS. We discuss the hemodynamic factors and unique challenges that need to be accounted for while developing treatment strategies for these patients. A summary of expert-based step-by-step recommendations to the approach and treatment of these patients, both in the field before admission and in-hospital management, are presented.

Steroid treatment as anti-inflammatory and neuroprotective agent following out-of-hospital cardiac arrest: a randomized clinical trial

Background

Patients resuscitated from out-of-hospital cardiac arrest (OHCA) have a high morbidity and mortality risk and often develop post-cardiac arrest syndrome (PCAS) involving systemic inflammation. The severity of the inflammatory response is associated with adverse outcome, with anoxic irreversible brain injury as the leading cause of death following resuscitated OHCA. The study aimed to investigate the anti-inflammatory and neuroprotective effect of pre-hospital administration of a high-dose glucocorticoid following OHCA.

Methods

The study is an investigator-initiated, randomized, multicenter, single-blinded, placebo-controlled, clinical trial. Inclusion will continue until one hundred twenty unconscious OHCA patients surviving a minimum of 72 h are randomized. Intervention is a 1:1 randomization to an infusion of methylprednisolone 250 mg following a minimum of 5 min of sustained return of spontaneous circulation in the pre-hospital setting. Methylprednisolone will be given as a bolus infusion of 1 × 250 mg (1 × 4 mL) over a period of 5 min. Patients allocated to placebo will receive 4 mL of isotonic saline (NaCl 0.9%). Main eligibility criteria are OHCA of presumed cardiac cause, age ≥ 18 years, Glasgow Coma Scale ≤ 8, and sustained ROSC for at least 5 min. Co-primary endpoint: Reduction of interleukin-6 and neuron-specific-enolase. Secondary endpoints: Markers of inflammation, brain, cardiac, kidney and liver damage, hemodynamic and hemostatic function, safety, neurological function at follow-up, and mortality. A research biobank is set up with blood samples taken daily during the first 72 h from hospitalization to evaluate primary and secondary endpoints.

Discussion

We hypothesize that early anti-inflammatory steroid treatment in the pre-hospital setting can mitigate the progression of PCAS following resuscitated OHCA. Primary endpoints will be assessed through analyses of biomarkers for inflammation and neurological damage taken during the first 72 h of admission.

Trial registration

EudraCT number: 2020-000855-11; submitted March 30, 2020

ClinicalTrials.gov Identifier: NCT04624776; submitted October 12, 2020, first posted November 10, 2020

Effects of Methylprednisolone on Myocardial Function and Microcirculation in Post-resuscitation: A Rat Model

Background

Previous studies have demonstrated that inflammation and impaired microcirculation are key factors in post-resuscitation syndromes. Here, we investigated whether methylprednisolone (MP) could improve myocardial function and microcirculation by suppressing the systemic inflammatory response following cardiopulmonary resuscitation (CPR) in a rat model of cardiac arrest (CA).

Methods

Sprague-Dawley rats were randomly assigned to (1) sham, (2) control, and (3) drug groups. Ventricular fibrillation was induced and then followed by CPR. The rats were infused with either MP or vehicle at the start of CPR. Myocardial function and microcirculation were assessed at baseline and after the restoration of spontaneous circulation. Blood samples were drawn at baseline and 60-min post-resuscitation to assess serum cytokine (TNF-α, IL-1β, and IL-6) levels.

Results

Myocardial function [estimated by the ejection fraction (EF), myocardial performance index (MPI), and cardiac output (CO)] improved post-ROSC in the MP group compared with those in the control group (p &lt; 0.05). MP decreased the levels of the aforementioned pro-inflammatory cytokines and alleviated cerebral, sublingual, and intestinal microcirculation compared with the control (p &lt; 0.05). A negative correlation emerged between the cytokine profile and microcirculatory blood flow.

Conclusion

MP treatment reduced post-resuscitation myocardial dysfunction, inhibited pro-inflammatory cytokines, and improved microcirculation in the initial recovery phase in a CA and resuscitation animal model. Therefore, MP could be a potential clinical target for CA patients in the early phase after CPR to alleviate myocardial dysfunction and improve prognosis.

Physiologic effects of stress dose corticosteroids in in-hospital cardiac arrest (CORTICA): A randomized clinical trial

Aim

Postresuscitation hemodynamics are associated with hospital mortality/functional outcome. We sought to determine whether low-dose steroids started during and continued after cardiopulmonary resuscitation (CPR) affect postresuscitation hemodynamics and other physiological variables in vasopressor-requiring, in-hospital cardiac arrest.

Methods

We conducted a two-center, randomized, double-blind trial of patients with adrenaline (epinephrine)-requiring cardiac arrest. Patients were randomized to receive either methylprednisolone 40 mg (steroids group) or normal saline-placebo (control group) during the first CPR cycle post-enrollment. Postresuscitation shock was treated with hydrocortisone 240 mg daily for 7 days maximum and gradual taper (steroids group), or saline-placebo (control group). Primary outcomes were arterial pressure and central-venous oxygen saturation (ScvO₂) within 72 hours post-ROSC.

Results

Eighty nine of 98 controls and 80 of 86 steroids group patients with ROSC were treated as randomized. Primary outcome data were collected from 100 patients with ROSC (control, n = 54; steroids, n = 46). In intention-to-treat mixed-model analyses, there was no significant effect of group on arterial pressure, marginal mean (95% confidence interval) for mean arterial pressure, steroids vs. control: 74 (68–80) vs. 72 (66–79) mmHg] and ScvO₂ [71 (68–75)% vs. 69 (65–73)%], cardiac index [2.8 (2.5–3.1) vs. 2.9 (2.5–3.2) L/min/m²], and serum cytokine concentrations [e.g. interleukin-6, 89.1 (42.8–133.9) vs. 75.7 (52.1–152.3) pg/mL] determined within 72 hours post-ROSC (P = 0.12–0.86). There was no between-group difference in body temperature, echocardiographic variables, prefrontal blood flow index/cerebral autoregulation, organ failure-free days, and hazard for poor in-hospital/functional outcome, and adverse events (P = 0.08–>0.99).

Conclusions

Our results do not support the use of low-dose corticosteroids in in-hospital cardiac arrest.

Trial Registration:ClinicalTrials.gov number: NCT02790788 (https://www.clinicaltrials.gov).

Association between inflammatory markers and survival in comatose, resuscitated out-of-hospital cardiac arrest patients

OBJECTIVES

Prognostication after out-of-hospital cardiac arrest (OHCA) remains challenging. The inflammatory response after OHCA has been associated with increased mortality. This study investigates the associations and predictive value between inflammatory markers and outcome in resuscitated OHCA patients.

DESIGN

The study is based on post hoc analyses of a double-blind controlled trial, where resuscitated OHCA patients were randomized to receive either exenatide or placebo. Blood was analyzed for levels of inflammatory markers the day following admission. Primary endpoint was time to death for up to 180 days. Secondary endpoints included 180-day mortality and poor neurological outcome after 180 days, defined as a cerebral performance category (CPC) of 3 to 5.

RESULTS

Among 110 included patients we found significant associations between higher leucocyte quartile and increasing mortality in univariable analysis (OR 2.6 (95%CI 1.6-4.2), p < .001), as well as in multivariable analysis (OR 2.1 (95%CI 1.1-4.0), p = .02). A significant association was found between higher neutrophil quartile and increasing mortality in univariable analysis (OR 3.0 (95%CI 1.8-5.0), p < .001) as well as multivariable analysis (OR 2.4 (95%CI 1.2-4.6), p = .01). Leucocyte and neutrophil levels were predictive of poor outcome after 180 days with area under the receiver operating characteristics curves of 0.79 and 0.81, respectively. We found no associations between CRP and lymphocyte levels versus outcome.

CONCLUSIONS

Total leucocyte count and neutrophil levels measured the first day following OHCA were significantly associated with 180-day all-cause mortality and may potentially act as early predictors of outcome.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov, unique identifier: NCT02442791.

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.

Real-Time Brain Monitoring by Near-Infrared Spectroscopy Predicts Neurological Outcome after Cardiac Arrest and Resuscitation in Rats: A Proof of Concept Study of a Novel Prognostic Measure after Cardiac Arrest

Clinical studies have demonstrated that dynamic changes in regional cerebral oxygen saturation (rSO₂) after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) have a role in predicting neurological outcomes after the return of spontaneous circulation (ROSC). Our study evaluated whether the timing of rSO₂ decline shortly after CPR reflects the severity of brain injury in a rat model of CA. Rats were subjected to different durations of asphyxia to produce variable severities of brain injury, due to CA. Time from ROSC to achieving the initial minimum rSO₂ was defined as T_nadir. A T_nadir cut-off of 24 min had optimal sensitivity and specificity for predicting good neurological outcomes at 72 h after ROSC (AUC, 0.88; sensitivity, 89%; specificity, 86%; p < 0.01). Immunohistochemistry at 72 h post-CA revealed that the number of Fluoro-Jade B positive degenerating neurons in the hippocampus CA1 sector were markedly higher in animals with T_nadir > 24 min than that in animals with T_nadir ≤ 24 min. There was no difference in the gene expressions of cytokines and mitochondrial fission proteins in the brain at 2 h after ROSC between rats with T_nadir > 24 min and with T_nadir ≤ 24 min. In conclusion, T_nadir can be a novel predictor of good neurological outcomes after CA/CPR.

Impact of rewarming rate on interleukin-6 levels in patients with shockable cardiac arrest receiving targeted temperature management at 33 °C: the ISOCRATE pilot randomized controlled trial

Purpose

While targeted temperature management (TTM) has been recommended in patients with shockable cardiac arrest (CA) and suggested in patients with non-shockable rhythms, few data exist regarding the impact of the rewarming rate on systemic inflammation. We compared serum levels of the proinflammatory cytokine interleukin-6 (IL6) measured with two rewarming rates after TTM at 33 °C in patients with shockable out-of-hospital cardiac arrest (OHCA).

Methods

ISOCRATE was a single-center randomized controlled trial comparing rewarming at 0.50 °C/h versus 0.25 °C/h in patients coma after shockable OHCA in 2016–2020. The primary outcome was serum IL6 level 24–48 h after reaching 33 °C. Secondary outcomes included the day-90 Cerebral Performance Category (CPC) and the 48-h serum neurofilament light-chain (NF-L) level.

Results

We randomized 50 patients. The median IL6 area-under-the-curve was similar between the two groups (12,389 [7256–37,200] vs. 8859 [6825–18,088] pg/mL h; P = 0.55). No significant difference was noted in proportions of patients with favorable day-90 CPC scores (13/25 patients at 0.25 °C/h (52.0%; 95% CI 31.3–72.2%) and 13/25 patients at 0.50 °C/h (52.0%; 95% CI 31.3–72.2%; P = 0.99)). Median NF-L levels were not significantly different between the 0.25 °C/h and 0.50 °C/h groups (76.0 pg mL, [25.5–3074.0] vs. 192 pg mL, [33.6–4199.0]; P = 0.43; respectively).

Conclusion

In our RCT, rewarming from 33 °C at 0.25 °C/h, compared to 0.50 °C/h, did not decrease the serum IL6 level after shockable CA. Further RCTs are needed to better define the optimal TTM strategy for patients with CA.

Trial registration ClinicalTrials.gov, NCT02555254. Registered September 14, 2015.

Take-Home Message: Rewarming at a rate of 0.25 °C/h, compared to 0.50 °C, did not result in lower serum IL6 levels after achievement of hypothermia at 33 °C in patients who remained comatose after shockable cardiac arrest. No associations were found between the slower rewarming rate and day-90 functional outcomes or mortality.

140-character Tweet: Rewarming at 0.25 °C versus 0.50 °C did not decrease serum IL6 levels after hypothermia at 33 °C in patients comatose after shockable cardiac arrest.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03842-9.

The inflammatory response is related to circulatory failure after out-of-hospital cardiac arrest: A prospective cohort study

BACKGROUND

Whole body ischemia and reperfusion injury after cardiac arrest leads to the massive inflammation clinically manifested in the post-cardiac arrest syndrome. Previous studies on the inflammatory effect on circulatory failure after cardiac arrest have either investigated a selected patient group or a limited part of the inflammatory mechanisms. We examined the association between cardiac arrest characteristics and inflammatory biomarkers, and between inflammatory biomarkers and circulatory failure after cardiac arrest, in an unselected patient cohort.

METHODS

This was a prospective study of 50 consecutive patients with out-of-hospital cardiac arrest. Circulation was invasively monitored from admission until day five, whereas inflammatory biomarkers, i.e. complement activation, cytokines and endothelial injury, were measured daily. We identified predictors for an increased inflammatory response, and associations between the inflammatory response and circulatory failure.

RESULTS

We found a marked and broad inflammatory response in patients after cardiac arrest, which was associated with clinical outcome. Long time to return of spontaneous circulation and high lactate level at admission were associated with increased complement activation (TCC and C3bc), pro-inflammatory cytokines (IL-6, IL-8) and endothelial injury (syndecan-1) at admission. These biomarkers were in turn significantly associated with lower mean arterial blood pressure, lower cardiac output and lower systemic vascular resistance, and increased need of circulatory support in the initial phase. High levels of TCC and IL-6 at admission were significantly associated with increased 30-days mortality.

CONCLUSION

Inflammatory biomarkers, including complement activation, cytokines and endothelial injury, were associated with increased circulatory failure in the initial period after cardiac arrest.

Early Bronchoscopy Improves Extubation Rates after Out-of-Hospital Cardiac Arrest: A Retrospective Cohort Analysis

BACKGROUND

Patients suffering from out-of-hospital cardiac arrest (OHCA) frequently receive a bronchoscopy after being admitted to the ICU. We investigated the optimal timing and the outcome in these patients.

METHODS

All patients who suffered from OHCA and were treated in our ICU from January 2013 to December 2018 were retrospectively analyzed. The data were collected from the patients' medical files, and included duration of mechanical ventilation, antibiotics, microbiological test results and neurological outcome. The outcome was the effect of early bronchoscopy (≤48 h after administration) on the rate of intubated patients on day five and day seven.

RESULTS

From January 2013 to December 2018, 190 patients were admitted with OHCA. Bronchoscopy was performed in 111 patients out of the 164 patients who survived the first day. Late bronchoscopy >48 h was associated with higher rates of intubation on day five (OR 4.94; 95% CI 1.2-36.72, 86.7% vs. 55.0%, p = 0.036) and day seven (OR 4.96; 95% CI 1.38-24.69; 80.0% vs. 43.3%, p = 0.019).

CONCLUSION

This study shows that patients who suffered from OHCA might have a better outcome if they receive a bronchoscopy early after hospital admission. Our data suggests an association of early bronchoscopy with a shorter intubation period.

Skin sympathetic nerve activity as a biomarker for neurologic recovery during therapeutic hypothermia for cardiac arrest

BACKGROUND

Targeted temperature management (TTM) improves neurologic outcome after cardiac arrest. However, better neurologic prognostication is needed.

OBJECTIVE

The purpose of this study was to test the hypothesis that noninvasive recording of skin sympathetic nerve activity (SKNA) and its association with heart rate (HR) during TTM may serve as a biomarker of neurologic status.

METHODS

SKNA recordings were analyzed from 29 patients undergoing TTM. Patients were grouped based on Clinical Performance Category (CPC) score into group 1 (CPC 1-2) representing a good neurologic outcome and group 2 (CPC 3-5) representing a poor neurologic outcome.

RESULTS

Of the 29 study participants, 18 (62%) were deemed to have poor neurologic outcome. At all timepoints, low average skin sympathetic nerve activity (aSKNA) was associated with poor neurologic outcome (odds ratio 22.69; P = .002) and remained significant (P = .03) even when adjusting for presenting clinical factors. The changes in aSKNA and HR during warming in group 1 were significantly correlated (ρ = 0.49; P <.001), even when adjusting for corresponding temperature and mean arterial pressure measurements (P = .017), whereas this correlation was not observed in group 2. Corresponding to high aSKNA, there was increased nerve burst activity during warming in group 1 compared to group 2 (0.739 ± 0.451 vs 0.176 ± 0.231; P = .013).

CONCLUSION

Neurologic recovery was retrospectively associated with SKNA. Patients undergoing TTM who did not achieve neurologic recovery were associated with low SKNA and lacked a significant correlation between SKNA and HR. These preliminary results indicate that SKNA may potentially be a useful biomarker to predict neurologic status in patients undergoing TTM.

Opportunities, controversies, and challenges of extracorporeal hemoadsorption with CytoSorb during ECMO

Extracorporeal membrane oxygenation (ECMO) is frequently used in many centers around the globe for various indications. However, prognosis is often poor even with all supportive therapies, and in many cases, clinical deterioration is associated with inflammation. Hemoadsorption with CytoSorb is a novel approach to limit the inflammatory response, and the device can be safely and easily installed into ECMO circuits. CytoSorb has been used more than 130.000 times to date, but because randomized controlled trials are largely lacking, there is substantial debate on its use. Here, experts from critical care medicine, cardiology, cardiac surgery, and perfusion technology discuss the pros and cons of this novel therapy and outline the future aspects for its clinical application and research.

Predicting neurological outcome after out-of-hospital cardiac arrest with cumulative information; development and internal validation of an artificial neural network algorithm

Background

Prognostication of neurological outcome in patients who remain comatose after cardiac arrest resuscitation is complex. Clinical variables, as well as biomarkers of brain injury, cardiac injury, and systemic inflammation, all yield some prognostic value. We hypothesised that cumulative information obtained during the first three days of intensive care could produce a reliable model for predicting neurological outcome following out-of-hospital cardiac arrest (OHCA) using artificial neural network (ANN) with and without biomarkers.

Methods

We performed a post hoc analysis of 932 patients from the Target Temperature Management trial. We focused on comatose patients at 24, 48, and 72 h post-cardiac arrest and excluded patients who were awake or deceased at these time points. 80% of the patients were allocated for model development (training set) and 20% for internal validation (test set). To investigate the prognostic potential of different levels of biomarkers (clinically available and research-grade), patients’ background information, and intensive care observation and treatment, we created three models for each time point: (1) clinical variables, (2) adding clinically accessible biomarkers, e.g., neuron-specific enolase (NSE) and (3) adding research-grade biomarkers, e.g., neurofilament light (NFL). Patient outcome was the dichotomised Cerebral Performance Category (CPC) at six months; a good outcome was defined as CPC 1–2 whilst a poor outcome was defined as CPC 3–5. The area under the receiver operating characteristic curve (AUROC) was calculated for all test sets.

Results

AUROC remained below 90% when using only clinical variables throughout the first three days in the ICU. Adding clinically accessible biomarkers such as NSE, AUROC increased from 82 to 94% (p < 0.01). The prognostic accuracy remained excellent from day 1 to day 3 with an AUROC at approximately 95% when adding research-grade biomarkers. The models which included NSE after 72 h and NFL on any of the three days had a low risk of false-positive predictions while retaining a low number of false-negative predictions.

Conclusions

In this exploratory study, ANNs provided good to excellent prognostic accuracy in predicting neurological outcome in comatose patients post OHCA. The models which included NSE after 72 h and NFL on all days showed promising prognostic performance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03505-9.

The Value of Extracellular Cold-Inducible RNA-Binding Protein (eCIRP) in Predicting the Severity and Prognosis of Patients After Cardiac Arrest: A Preliminary Observational Study

BACKGROUND

Extracellular cold-inducible RNA-binding protein (eCIRP) acting as a novel damage-associated molecular pattern molecule promotes systemic inflammatory responses, including neuroinflammation in cerebral ischemia. We aimed to observe the changes of serum eCIRP and evaluate whether the increased serum eCIRP was associated with the severity and prognosis in patients with restoration of spontaneous circulation (ROSC).

METHODS

A total of 73 patients after ROSC were divided into non-survivor (n = 48) and survivor (n = 25) groups based on 28-day survival. Healthy volunteers (n = 25) were enrolled as controls. Serum eCIRP, procalcitonin (PCT), the pro-inflammatory mediators tumor necrosis factor (TNF)-α, interleukin-6 (IL)-6 and high mobility group protein (HMGB1), the neurological damage biomarkers neuron-specific enolase (NSE), and soluble protein 100β (S100β) were measured on days 1, 3, and 7 after ROSC. Clinical data and laboratory findings were collected, and the Sequential Organ Failure Assessment (SOFA) score and Acute Physiology and Chronic Health Evaluation (APACHE II) were calculated concurrently. Cerebral performance category scores on day 28 after ROSC were recorded.

RESULTS

Serum eCIRP, IL-6, TNF-α, PCT, and HMGB1, NSE and S100β were significantly increased within the first week after ROSC. The increased levels of eCIRP were positively correlated with IL-6, TNF-α, lactate, NSE, S100β, CPR time, SOFA score, APACHE II score, and HMGB1 after ROSC. Serum eCIRP on days 1, 3, and 7 after ROSC could predict 28-day mortality and neurological prognosis. Serum eCIRP on day 3 after ROSC had a biggest AUC [0.862 (95% CI: 0.741-0.941)] for 28-day mortality and a biggest AUC [0.807 (95% CI: 0.630-0.981)] for neurological prognosis.

CONCLUSIONS

Systemic inflammatory response with increased serum eCIRP occurred in patients after ROSC. Increased eCIRP level was positively correlated with the aggravation of systemic inflammatory response and the severity after ROSC. Serum eCIRP serves as a potential predictor for 28-day mortality and poor neurological prognosis after ROSC.

Ultrafast Hypothermia Selectively Mitigates the Early Humoral Response After Cardiac Arrest

Background

Total liquid ventilation (TLV) has been shown to prevent neurological damage though ultrafast cooling in animal models of cardiac arrest. We investigated whether its neuroprotective effect could be explained by mitigation of early inflammatory events.

Methods and Results

Rabbits were submitted to 10 minutes of ventricular fibrillation. After resuscitation, they underwent normothermic follow‐up (control) or ultrafast cooling by TLV and hypothermia maintenance for 3 hours (TLV). Immune response, survival, and neurological dysfunction were assessed for 3 days. TLV improved neurological recovery and reduced cerebral lesions and leukocyte infiltration as compared with control (eg, neurological dysfunction score=34±6 versus 66±6% at day 1, respectively). TLV also significantly reduced interleukin‐6 blood levels during the hypothermic episode (298±303 versus 991±471 pg/mL in TLV versus control at 3 hours after resuscitation, respectively), but not after rewarming (752±563 versus 741±219 pg/mL in TLV versus control at 6 hours after resuscitation, respectively). In vitro assays confirmed the high temperature sensitivity of interleukin‐6 secretion. Conversely, TLV did not modify circulating high‐mobility group box 1 levels or immune cell recruitment into the peripheral circulation. The link between interleukin‐6 early transcripts (<8 hours) and neurological outcome in a subpopulation of the previously described Epo‐ACR‐02 (High Dose of Erythropoietin Analogue After Cardiac Arrest) trial confirmed the importance of this cytokine at the early stages as compared with delayed stages (>8 hours).

Conclusions

The neuroprotective effect of hypothermic TLV was associated with a mitigation of humoral interleukin‐6 response. A temperature‐dependent attenuation of immune cell reactivity during the early phase of the post–cardiac arrest syndrome could explain the potent effect of rapid hypothermia.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00999583.

High plasma levels of pro-inflammatory factors interleukin-17 and interleukin-23 are associated with poor outcome of cardiac-arrest patients: a single center experience

Background

Systemic inflammation is an important feature of post-cardiac arrest syndrome (PCAS). This study was designed to determine whether the plasma concentrations of some circulating pro-inflammatory cytokines (interleukin-17 [IL-8], IL-22, IL-23 and IL-33) are of value in predicting the outcome of patients after return of spontaneous circulation (ROSC) during the post–cardiac arrest period.

Methods

This was a prospective observational clinical study. In total, 21 patients (survivors, n = 10; non-survivors, n = 11) who experienced cardiac arrest and successful ROSC with expected survival of at least 7 days were consecutively enrolled from January 2016 to December 2017. Of the 21 enrolled patients, ten survived were designated “survivors”. The other eleven patients died between 2 days and 1 months post ROSC. Venous blood was drawn at three time-points: baseline (< 1 h post ROSC), 2 days post ROSC and 7 days post ROSC. Plasma IL-8, IL-22, IL-23 and IL-33 were determined using commercial enzyme-linked immunosorbent assays.

Results

Plasma creatinine levels, but aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, were elevated in non-survivors compared with survivors. Plasma levels of IL-17, IL-22, IL-23 and IL-33 of the 21 total patients did not change at 2 or 7 days post ROSC compared to baseline. In survivors, the plasma levels of IL-17 and IL-23 at 2 or 7 days post ROSC were lower than baseline. In non-survivors, plasma levels of IL-17 increased compared with baseline. Receiver operating characteristic curve analysis showed that the plasma levels of IL-17 and IL-23 at 2 or 7 days post ROSC were able to predict the mortality of PCAS patients, and positively correlated with Acute Physiology and Chronic Health Evaluation (APACHE)-II score and time to ROSC.

Conclusion

These results provide the first evidence that the elevated plasma IL-17 and IL-23 levels are associated with poor outcome in PCAS patients. The role of IL-17/IL-23 axis post ROSC is worth paying attention to in PCAS patients.

Trial registration

Clinicaltrial.govNCT02297776, 2014-11-21.

Hydrogen gas inhalation alleviates oxidative stress in patients with post-cardiac arrest syndrome

Oxidative stress plays a key role in the pathophysiology of post-cardiac arrest syndrome. Molecular hydrogen reduces oxidative stress and exerts anti-inflammatory effects in an animal model of cardiac arrest. However, its effect on human post-cardiac arrest syndrome is unclear. We consecutively enrolled five comatose post-cardiac arrest patients (three males; mean age, 65 ± 15 years; four cardiogenic, one septic cardiac arrest) and evaluated temporal changes in oxidative stress markers and cytokines with inhaled hydrogen. All patients were treated with target temperature management. Hydrogen gas inhalation (2% hydrogen with titrated oxygen) was initiated upon admission for 18 h. Blood hydrogen concentrations, plasma and urine oxidative stress markers (derivatives of reactive oxygen metabolites, biological antioxidant potential, 8-hydroxy-2'-deoxyguanosine, N^ɛ-hexanoyl-lysine, lipid hydroperoxide), and cytokines (interleukin-6 and tumor necrosis factor-α) were measured before and 3, 9, 18, and 24 h after hydrogen gas inhalation. Arterial hydrogen concentration was measurable and it was equilibrated with inhaled hydrogen. Oxidative stress was reduced and cytokine levels were unchanged in cardiogenic patients, whereas oxidative stress was unchanged and cytokine levels were diminished in the septic patient. The effect of inhaled hydrogen on oxidative stress and cytokines in comatose post-cardiac arrest patients remains indefinite because of methodological weaknesses.

Inflammatory biomarkers to predict adverse outcomes in postoperative patients with acute type A aortic dissection

Objectives. The present study aimed to evaluate prognostic value of inflammatory markers for in-hospital mortality and renal complication in patients undergoing surgery for acute type A aortic dissection (ATAAD). Design. Serum concentration of C-reactive protein, leukocyte counts, procalcitonin (PCT), tumor necrosis factor (TNF)-α, interleukin-2 receptor (IL-2R), IL-6 and IL-8 were measured on the day of admission to the hospital (T0) and on 1st (T1), 2nd (T2), and 7th (T3) day after surgery. Results. 328 patients were included. There were significant differences between survivor group and non-survivor group in PCT, IL-2R, and IL-6 (p = .001, p = .015, and p = .005). There were significant differences between patients with different AKI stage in PCT and IL-2R (p = .001, p < .001). The area under receiver operating characteristics (ROC) curve on 30-day death was 0.686 for PCT, 0.718 for IL-2R, 0.694 for IL-6 and 0.627 for IL-8. The area under ROC curve on stage III AKI was 0.852 for PCT, 0.749 for IL-2R, 0.626 for IL-8, and 0.636 for TNF-α. IL-2 > 1438 U/ml and IL-6 > 45.5 pg/ml were independently associated with 30-day mortality (p = .014 and p < .001). The area under ROC curve was 0.849 on score 2 (using 1 point for PCT > 4.58 ng/ml, 1 point for IL-2R > 1438 U/ml, 1 point for APACHE II score >15.5, and 1 point for IL-6 > 45.5 pg/ml). Conclusions. PCT and cytokines may be considered as predictors for adverse renal outcomes and mortality in patients with ATAAD patients after surgery. They are earlier than traditional biomarkers and combination of these biomarkers will improve the accuracy.

Growth differentiation factor 15 and early prognosis after out-of-hospital cardiac arrest

BACKGROUND

Growth differentiation factor 15 (GDF-15) is an inflammatory cytokine released in response to tissue injury. It has prognostic value in cardiovascular diseases and other acute and chronic conditions. Here, we explored the value of GDF-15 as an early predictor of neurologic outcome after an out-of-hospital cardiac arrest (OHCA).

METHODS

Prospective registry study of patients in coma after an OHCA, admitted in the intensive cardiac care unit from a single university center. Serum levels of GDF-15 were measured on admission. Neurologic status was evaluated according to the cerebral performance category (CPC) scale. The relationship between GDF-15 levels and poor neurologic outcome at 6 months was analyzed.

RESULTS

Among 62 patients included, 32 (51.6%) presented poor outcome (CPC 3-5). Patients with CPC 3-5 exhibited significantly higher GDF-15 levels (median, 17.1 [IQR, 11.1-20.4] ng/mL) compared to those with CPC 1-2 (7.6 [IQR, 4.1-13.1] ng/mL; p = 0.004). Multivariable logistic regression analyses showed that age (OR, 1.09; 95% CI 1.01-1.17; p = 0.020), home setting arrest (OR, 8.07; 95% CI 1.61-40.42; p = 0.011), no bystander cardiopulmonary resuscitation (OR, 7.91; 95% CI 1.84-34.01; p = 0.005), and GDF-15 levels (OR, 3.74; 95% CI 1.32-10.60; p = 0.013) were independent predictors of poor outcome. The addition of GDF-15 in a dichotomous manner (≥ 10.8 vs. < 10.8 ng/mL) to the resulting clinical model improved discrimination; it increased the area under the curve from 0.867 to 0.917, and the associated continuous net reclassification improvement was 0.90 (95% CI 0.48-1.44), which allowed reclassification of 37.1% of patients.

CONCLUSIONS

After an OHCA, increased GDF-15 levels were an independent, early predictor of poor neurologic outcome. Furthermore, when added to the most common clinical factors, GDF-15 improved discrimination and allowed patient reclassification.

Increased Citrullinated Histone H3 Levels in the Early Post-Resuscitative Period Are Associated with Poor Neurologic Function in Cardiac Arrest Survivors-A Prospective Observational Study

The exact contribution of neutrophils to post-resuscitative brain damage is unknown. We aimed to investigate whether neutrophil extracellular trap (NET) formation in the early phase after return of spontaneous circulation (ROSC) may be associated with poor 30 day neurologic function in cardiac arrest survivors. This study prospectively included adult (≥18 years) out-of-hospital cardiac arrest (OHCA) survivors with cardiac origin, who were subjected to targeted temperature management. Plasma levels of specific (citrullinated histone H3, H3Cit) and putative (cell-free DNA (cfDNA) and nucleosomes) biomarkers of NET formation were assessed at 0 and 12 h after admission. The primary outcome was neurologic function on day 30 after admission, which was assessed using the five-point cerebral performance category (CPC) score, classifying patients into good (CPC 1–2) or poor (CPC 3–5) neurologic function. The main variable of interest was the effect of H3Cit level quintiles at 12 h on 30 day neurologic function, assessed by logistic regression. The first quintile was used as a baseline reference. Results are given as crude odds ratio (OR) with 95% confidence interval (95% CI). Sixty-two patients (79% male, median age: 57 years) were enrolled. The odds of poor neurologic function increased linearly, with 0 h levels of cfNDA (crude OR 1.8, 95% CI: 1.2–2.7, p = 0.007) and nucleosomes (crude OR 1.7, 95% CI: 1.0–2.2, p = 0.049), as well as with 12 h levels of cfDNA (crude OR 1.6, 95% CI: 1.1–2.4, p = 0.024), nucleosomes (crude OR 1.7, 95% CI: 1.1–2.5, p = 0.020), and H3Cit (crude OR 1.6, 95% CI: 1.1–2.3, p = 0.029). Patients in the fourth (7.9, 95% CI: 1.1–56, p = 0.039) and fifth (9.0, 95% CI: 1.3–63, p = 0.027) H3Cit quintile had significantly higher odds of poor 30 day neurologic function compared to patients in the first quintile. Increased plasma levels of H3Cit, 12 h after admission, are associated with poor 30 day neurologic function in adult OHCA survivors, which may suggest a contribution of NET formation to post-resuscitative brain damage and therefore provide a therapeutic target in the future.

Number of Circulating CD 73-Expressing Lymphocytes Correlates With Survival After Cardiac Arrest

Background

Patients resuscitated from cardiac arrest (CA) have highly variable neurological, circulatory, and systemic ischemia‐reperfusion injuries. After the initial hypoxic‐ischemic insult, a cascade of immune and inflammatory responses develops and is often fatal. The role of the immune response in pathophysiological characteristics and recovery is not well understood. We studied immune cell activity and its association with outcomes in a cohort of CA survivors.

Methods and Results

After informed consent, we collected blood samples at intervals over a week after resuscitation from CA. We examined the expression of CD39 and CD73 (alias 5′‐nucleotidase), production of tumor necrosis factor‐α, generation of reactive oxygen species, and secretion of vascular endothelial growth factor by circulating myeloid and lymphoid cells, in comparison to cells obtained from control subjects before coronary artery bypass grafting surgery. The number of circulating total and CD73‐expressing lymphocytes correlated with survival after CA. Incubation of immune cells, obtained from post‐CA subjects, with AMP, a substrate for CD73, resulted in inhibition of tumor necrosis factor‐α production and generation of reactive oxygen species. This effect was blocked by adenosine 5′‐(α, β‐methylene) diphosphate, a specific inhibitor of CD73 and ZM 241385, an A2 adenosine receptor antagonist. We also found that AMP‐dependent activation of CD73 induces production of vascular endothelial growth factor.

Conclusions

CD73‐expressing lymphocytes mediate cellular protection from inflammation after CA through inhibition of proinflammatory activation of myeloid cells and promotion of vascular endothelial growth factor secretion. The contribution of CD73 lymphocytes in the regulation of acute inflammation and tissue injury after CA warrants further study.

Cytokine Adsorption in Critically Ill Patients Requiring ECMO Support

Systemic inflammation is a key characteristic of sepsis but also also in non-infectious conditions such as post-cardiac arrest syndrome. Cytokine adsorption and extracorporeal membrane oxygenation are emerging therapies applied in these critically ill patients, but the experience with their concurrent use is limited. We evaluated cytokine adsorption in critically ill patients requiring support with either veno-venous (vv) or veno-arterial (va) extracorporeal membrane oxygenation (ECMO) support and hypothesized that adsorber incorporation into the ECMO circuit was technically feasible and not associated with imminent risk. We analyzed data from the first six cases of a prospective single-center registry of patients undergoing veno-venous (vv) or veno-arterial (va) ECMO therapy. While in most published cases cytokine adsorbers were inserted into a hemofiltration circuit, we directly incorporated the adsorber into the ECMO circuit without interruption of continuous ECMO support. We observed no relevant side effects attributable to cytokine adsorption. Thirty-day mortality was 83% (predicted mortality 87%), indicating that the decision for adding cytokine adsorption may have been considered as an ultima ratio decision in severe cases with poor prognosis. Vasopressor or inotrope use, lactate level, and fluid balance did not change significantly when comparing pre- vs. post-cytokine adsorption values. Interestingly, the real-time course of the mentioned three surrogate parameters remained unaltered in all but two cases, regardless of cytokine removal. Beneficial effects of cytokine adsorption are plausible in two va-ECMO-treated patient, where increasing lactate began to drop after initiation of cytokine adsorption. Taken together, these data suggest that incorporation of cytokine adsorption into the management of critically ill patients requiring continued ECMO support is feasible and easy to handle. Whether cytokine removal improves clinical outcome in ECMO-treated patients should now be investigated in randomized controlled trials.

Serum tau fragments as predictors of death or poor neurological outcome after out-of-hospital cardiac arrest

Background: Anoxic brain injury is the primary cause of death after resuscitation from out-of-hospital cardiac arrest (OHCA) and prognostication is challenging. The aim of this study was to evaluate the potential of two fragments of tau as serum biomarkers for neurological outcome. Methods: Single-center sub-study of 171 patients included in the Target Temperature Management (TTM) Trial randomly assigned to TTM at 33 °C or TTM at 36 °C for 24 h after OHCA. Fragments (tau-A and tau-C) of the neuronal protein tau were measured in serum 24, 48 and 72 h after OHCA. The primary endpoint was neurological outcome. Results: Median (quartile 1 - quartile 3) tau-A (ng/ml) values were 58 (43-71) versus 51 (43-67), 72 (57-84) versus 71 (59-82) and 76 (61-92) versus 75 (64-89) for good versus unfavourable outcome at 24, 48 and 72 h, respectively (p_group = 0.95). Median tau C (ng/ml) values were 38 (29-50) versus 36 (29-49), 49 (38-58) versus 48 (33-59) and 48 (39-59) versus 48 (36-62) (p_group = 0.95). Tau-A and tau-C did not predict neurological outcome (area under the receiver-operating curve at 48 h; tau-A: 0.51 and tau-C: 0.51). Conclusions: Serum levels of tau fragments were unable to predict neurological outcome after OHCA.

Chemokine RANTES and IL-1β in mild therapeutic hypothermia-treated patients after out-of-hospital sudden cardiac arrest

INTRODUCTION

CCL5/RANTES and IL-1β, which regulate the immune response, may have an impact on survival in patients with acute coronary syndrome (ACS) and sudden cardiac arrest (SCA).

AIM

To evaluate levels of CCL5/RANTES and IL-1β in patients with ACS complicated by SCA, treated with coronary angioplasty (PCI) and mild therapeutic hypothermia (MTH), and these chemokines' impact on the 30- and 180-day survival.

MATERIAL AND METHODS

Thirty-three unconscious patients admitted after SCA with ACS underwent PCI and MTH treatment. CCL5/RANTES and IL-1β were evaluated on admission (T0), at 12-24 h (T1) and at 48-72 h (T2). All-cause mortality was recorded at 30 and 180 days.

RESULTS

We observed a statistically significant decrease in median levels of CCL/RANTES at T0, T1 and T2 (24.69 ng/ml vs. 3.89 ng/ml vs. 2.71 ng/ml; p < 0.001), and significant differences in median levels of IL-1β (0.196 pg/ml vs. 0.171 pg/ml vs. 0.214 pg/ml; p = 0.034). Initial levels of CCL5/RANTES and IL-1β correlated significantly (r = -0.360; p = 0.045). At T2, CCL5/RANTES correlated with the maximum levels of hs-TnT and CK-MB (r = -0.594; p < 0.001 and r = -0.389; p = 0.030), and at T0 with BNP (r = -0.521; p = 0.003). Mortality rate at 30 days and 180 days was 18.2% and 45.5%, respectively. At 30 days, we observed a trend to significance for IL-1β at T0 and T1 (p = 0.078 and p = 0.079), but not for CCL5/RANTES (p = 0.284 and p = 0.351). For 180-day survival curves, only the IL-1β level at T1 was associated with mortality (p = 0.028).

CONCLUSIONS

Although CCL5/RANTES levels correlate with cardiac injury and heart failure markers and they decrease during MTH, they failed to predict early and late mortality. In contrast, IL-1β level was associated with 180-day survival.

Non-Coding RNAs to Aid in Neurological Prognosis after Cardiac Arrest

Cardiovascular disease in general, and sudden cardiac death in particular, have an enormous socio-economic burden worldwide. Despite significant efforts to improve cardiopulmonary resuscitation, survival rates remain low. Moreover, patients who survive to hospital discharge have a high risk of developing severe physical or neurological symptoms. Being able to predict outcomes after resuscitation from cardiac arrest would make it possible to tailor healthcare approaches, thereby maximising efforts for those who would mostly benefit from aggressive therapy. However, the identification of patients at risk of poor recovery after cardiac arrest is still a challenging task which could be facilitated by novel biomarkers. Recent investigations have recognised the potential of non-coding RNAs to aid in outcome prediction after cardiac arrest. In this review, we summarize recent discoveries and propose a handful of novel perspectives for the use of non-coding RNAs to predict outcome after cardiac arrest, discussing their use for precision medicine.

The Role of Inflammatory Cytokines in Cardiac Arrest

Introduction:

Post-cardiac arrest syndrome (PCAS) is characterized by systemic ischemia/reperfusion injury, anoxic brain injury, and post-arrest myocardial dysfunction superimposed on a precipitating pathology. The role of inflammatory cytokines in cardiac arrest remains unclear.

Aims:

We aimed to describe, with an emphasis on clinical applications, what is known about the role of inflammatory cytokines in cardiac arrest.

Data Sources:

A PubMed literature review was performed for relevant articles. Only articles in English that studied cytokines in patients with cardiac arrest were included.

Results:

Cytokines play a crucial role in the pathogenesis of PCAS. Following cardiac arrest, the large release of circulating cytokines mediates the ischemia/reperfusion injury, brain dysfunction, and myocardial dysfunction seen. Interleukins, tumor necrosis factor, and matrix metalloproteinases all play a unique prognostic role in PCAS. High levels of inflammatory cytokines have been associated with mortality and/or poor neurologic outcomes. Interventions to modify the systemic inflammation seen in PCAS continue to be heavily studied. Currently, the only approved medical intervention for comatose patients following cardiac arrest is targeted temperature management. Medical agents, including minocycline and sodium sulfide, have demonstrated promise in animal models.

Conclusions:

The role of inflammatory cytokines for both short- and long-term outcomes is an important area for future investigation.

Venoarterial Extracorporeal Membrane Oxygenation Increased Immune Function of Spleen and Decreased Reactive Oxygen Species During Post-Resuscitation

We aimed to investigate the effect of venoarterial extracorporeal membrane oxygenation (VA-ECMO) on immune function of the spleen and reactive oxygen species (ROS) during post-resuscitation in a porcine model. After 8 min of untreated ventricular fibrillation and 6 min of basic life support, pigs were randomized into two groups: Group 1 received VA-ECMO and Group 2 received conventional cardiopulmonary resuscitation. After successful return of spontaneous circulation, the hemodynamic status was determined and blood samples were collected at 0, 1, 2, 4, and 6 h. Surviving pigs were euthanized 6 h after return of spontaneous circulation, their spleens were harvested and the T-cells were separated. Then, we investigated immune function parameters of the spleen and ROS levels. VA-ECMO increased the return of spontaneous circulation and 6 h survival rate after return of spontaneous circulation. Compared with the conventional cardiopulmonary resuscitation group, the VA-ECMO group showed increased superoxide dismutase and decreased malondialdehyde and ROS levels. Furthermore, VA-ECMO was associated with a high rate of CD4+ and CD4+/CD8+, high levels of interleukin 2, interferon γ, and interferon γ/interleukin 4, as well as high proliferation of lymphocytes. The apoptotic rate of T-cells was lower in the VA-ECMO group than it was in the conventional cardiopulmonary resuscitation group. VA-ECMO increased immune function of spleen and decreased ROS levels during post-resuscitation. Further research is expected to illustrate whether the differences in immune responses are due to ROS or some other perfusion related effect on spleen.

Interleukin-6 Levels in Cerebrospinal Fluid and Plasma in Patients with Severe Spontaneous Subarachnoid Hemorrhage

BACKGROUND

Inflammatory processes play a key role in the pathophysiology of subarachnoid hemorrhage (SAH). This study evaluated whether different temporal patterns of intrathecal and systemic inflammation could be identified in the acute phase after SAH. The intensity of the inflammation was also assessed in clinical subgroups.

METHODS

Cerebrospinal fluid (CSF) and blood samples were collected at days 1, 4, and 10 after ictus in 44 patients with severe SAH. Interleukin-6 (IL-6) was analyzed by a routine monoclonal antibody-based method. Median IL-6 values for each day were calculated. Day 4 IL-6 values were compared in dichotomized groups (age, sex, World Federation of Neurosurgical Societies [WFNS] grade, Fisher scale grade, outcome, vasospasm, central nervous system infection and systemic infections).

RESULTS

CSF IL-6 levels were significantly elevated from day 1 to days 4 and 10, whereas plasma IL-6 showed a different trend at lower levels. Median CSF IL-6 concentrations for days 1, 4, and 10 were 876.5, 3361, and 1567 ng/L, whereas plasma was 26, 27.5, and 15.9 ng/L, respectively. No significant differences in CSF concentrations were observed between the subgroups, with the most prominent one being in day 4 IL-6 in the WFNS subgroups (grades 1-3 vs. 4-5, 1158.5 vs. 5538 ng/L; P = 0.056). Patients with systemic infection had significantly higher plasma IL-6 concentrations than patients without infection (31 vs. 16.05 ng/L, respectively; P = 0.028).

CONCLUSIONS

Distinctly different inflammatory patterns could be seen intrathecally compared with the systemic circulation. In plasma, a significant difference in the intensity of the inflammation was seen in cases with systemic infection. No other subgroup showed statistically significant differences.

Methods for Defining the Neuroprotective Properties of Xenon

Xenon has features that make it an ideal general anesthetic agent; cost and scarcity mitigate xenon's widespread use in the operating room. Discovery of xenon's cytoprotective properties resulted in its application to thwart ongoing acute neurologic injury, an unmet clinical need. The discovery that xenon's neuroprotective effect interacts synergistically with targeted temperature management (TTM) led to its investigation in clinical settings, including in the management of the postcardiac arrest syndrome, in which TTM is indicated. Following successful demonstration of xenon's efficacy in combination with TTM in a preclinical model of porcine cardiac arrest, xenon plus TTM was shown to significantly decrease an imaging biomarker of brain injury for out of hospital cardiac arrest victims that had been successfully resuscitated. With the development of an efficient delivery system the stage is now set to investigate whether xenon improves survival, with good clinical outcome, for successfully resuscitated victims of a cardiac arrest.