Decreased percentages of plasmacytoid dendritic cells predict survival in critically ill patients

Critically ill patients admitted to intensive care units (ICUs) experience a broad variety of life-threatening conditions. Irrespective of the initial cause of hospitalization, many experience systemic immune dysregulation. Dendritic cells (DCs) are the most potent antigen-presenting cells and play a pivotal role in regulating the immune response by linking the innate to the adaptive immune system. The aim of this study was to analyze whether DCs or their respective subsets are associated with 30-d mortality in an unselected patient cohort admitted to a medical ICU with a cardiovascular focus. A total of 231 patients were included in this single-center prospective observational study. Blood was drawn at admission and after 72 h. Subsequently, flow cytometry was utilized for the analysis of DCs and their respective subsets. In the total cohort, low percentages of DCs were significantly associated with sepsis, respiratory failure, and septic shock. In particular, a significantly lower percentage of circulating plasmacytoid DCs (pDCs) was found to be a strong and independent predictor of 30-d mortality after adjustment for demographic and clinical variables with an hazard ratio of 4.2 (95% confidence interval: 1.3-13.3, P = 0.015). Additionally, low percentages of pDCs were correlated with additional markers of inflammation and organ dysfunction. In conclusion, we observed low percentages of DCs in patients admitted to an ICU experiencing sepsis, respiratory failure, and cardiogenic shock, suggesting their depletion as a contributing mechanism for the development of immune paralysis. In our cohort, pDCs were identified as the most robust subset to predict 30-d mortality.

Repeated occurrence of severe hypotension associated with azithromycin infusion in a patient with fulminant myocarditis: a case report

Background

Intravenous administration of azithromycin has been linked to severe hypotension in some case reports in the past. We report a further case of profound shock requiring excessive use of vasopressors and extracorporeal membrane oxygenation (ECMO).

Case summary

An 18-year-old Caucasian male was admitted due to fulminant myocarditis and signs of cardiogenic shock. He had to be put on venoarterial ECMO only hours after admission. Due to the occurrence of disseminated intravascular coagulation and heparin-induced thrombocytopenia, haemodynamic support was discontinued on Day 8. On Day 11 of his stay, the patient started to exhibit signs of severe infection and a single 1500 mg dose of azithromycin was prescribed. Immediately after starting the infusion, the patient developed profound hypotension and signs of cardiogenic shock. Consecutively, venoarterial ECMO had to be re-established, and the azithromycin infusion was stopped in the process. It took the restart of the compound to recognize the connection between the administration of the therapy and the occurrence of cardiogenic shock. After discontinuing azithromycin, no further sudden hypotensive episodes were recorded, and the patient received left ventricular assist device implantation as a bridge to recovery or transplant.

Discussion

Rapid-onset hypotension appears to be a very rare but important adverse drug reaction associated with intravenous administration of azithromycin. Factors such as preceding infection and reduced biventricular function may facilitate the described occurrence.

Scrutinizing the Role of Venoarterial Extracorporeal Membrane Oxygenation: Has Clinical Practice Outpaced the Evidence?

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for temporary mechanical circulatory support in various clinical scenarios has been increasing consistently, despite the lack of sufficient evidence regarding its benefit and safety from adequately powered randomized controlled trials. Although the ARREST trial (Advanced Reperfusion Strategies for Patients with Out-of-Hospital Cardiac Arrest and Refractory Ventricular Fibrillation) and a secondary analysis of the PRAGUE OHCA trial (Prague Out-of-Hospital Cardiac Arrest) provided some evidence in favor of VA-ECMO in the setting of out-of-hospital cardiac arrest, the INCEPTION trial (Early Initiation of Extracorporeal Life Support in Refractory Out-of-Hospital Cardiac Arrest) has not found a relevant improvement of short-term mortality with extracorporeal cardiopulmonary resuscitation. In addition, the results of the recently published ECLS-SHOCK trial (Extracorporeal Life Support in Cardiogenic Shock) and ECMO-CS trial (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock) discourage the routine use of VA-ECMO in patients with infarct-related cardiogenic shock. Ongoing clinical trials (ANCHOR [Assessment of ECMO in Acute Myocardial Infarction Cardiogenic Shock, NCT04184635], REVERSE [Impella CP With VA ECMO for Cardiogenic Shock, NCT03431467], UNLOAD ECMO [Left Ventricular Unloading to Improve Outcome in Cardiogenic Shock Patients on VA-ECMO, NCT05577195], PIONEER [Hemodynamic Support With ECMO and IABP in Elective Complex High-risk PCI, NCT04045873]) may clarify the usefulness of VA-ECMO in specific patient subpopulations and the efficacy of combined mechanical circulatory support strategies. Pending further data to refine patient selection and management recommendations for VA-ECMO, it remains uncertain whether the present usage of this device improves outcomes.

Mechanical Circulatory Support Systems in Fulminant Myocarditis: Recent Advances and Outlook

Background: Fulminant myocarditis (FM) constitutes a severe and life-threatening form of acute cardiac injury associated with cardiogenic shock. The condition is characterised by rapidly progressing myocardial inflammation, leading to significant impairment of cardiac function. Due to the acute and severe nature of the disease, affected patients require urgent medical attention to mitigate adverse outcomes. Besides symptom-oriented treatment in specialised intensive care units (ICUs), the necessity for temporary mechanical cardiac support (MCS) may arise. Numerous patients depend on these treatment methods as a bridge to recovery or heart transplantation, while, in certain situations, permanent MCS systems can also be utilised as a long-term treatment option. Methods: This review consolidates the existing evidence concerning the currently available MCS options. Notably, data on venoarterial extracorporeal membrane oxygenation (VA-ECMO), microaxial flow pump, and ventricular assist device (VAD) implantation are highlighted within the landscape of FM. Results: Indications for the use of MCS, strategies for ventricular unloading, and suggested weaning approaches are assessed and systematically reviewed. Conclusions: Besides general recommendations, emphasis is put on the differences in underlying pathomechanisms in FM. Focusing on specific aetiologies, such as lymphocytic-, giant cell-, eosinophilic-, and COVID-19-associated myocarditis, this review delineates the indications and efficacy of MCS strategies in this context.

Association of Periprocedural Inflammatory Activation With Increased Risk for Early Coronary Stent Thrombosis

BACKGROUND

Stent thrombosis is a rare but deleterious event. Routine coronary angiography with percutaneous coronary intervention (PCI) is often deferred in the presence of laboratory markers of acute inflammation to prevent complications. The aim of this study was to investigate whether an acute inflammatory state is associated with an increased risk of early stent thrombosis.

METHODS AND RESULTS

Within a prospective single-center registry, the association between preprocedural acute inflammatory activation, defined as C-reactive protein plasma levels >50 mg/L or a leukocyte count >12 g/L, and occurrence of early (≤30 days) stent thrombosis was evaluated. In total, 11 327 patients underwent PCI and of those, 6880 patients had laboratory results available. 49.6% of the study population received PCI for an acute coronary syndrome and 50.4% for stable ischemic heart disease. In patients with signs of acute inflammatory activation (24.9%), PCI was associated with a significantly increased risk for stent thrombosis (hazard ratio, 2.89; P<0.00001), independent of age, sex, kidney function, number and type of stents, presence of multivessel disease, choice of P2Y12 inhibitor, and clinical presentation. Elevated laboratory markers of acute inflammation were associated with the occurrence of stent thrombosis in both patients with acute coronary syndrome (hazard ratio, 2.63; P<0.001) and in patients with stable ischemic heart disease (hazard ratio, 3.57; P<0.001).

CONCLUSIONS

An acute inflammatory state at the time of PCI was associated with a significantly increased risk of early stent thrombosis. Evidence of acute inflammation should result in deferred PCI in elective patients, while future studies are needed for patients with acute coronary syndrome.

Simulation of bempedoic acid and ezetimibe in the lipid-lowering treatment pathway in Austria using the contemporary SANTORINI cohort of high and very high risk patients

OBJECTIVE

The low-density lipoprotein cholesterol goals in the 2019 European Society of Cardiology/European Atherosclerosis Society dyslipidaemia guidelines necessitate greater use of combination therapies. We describe a real-world cohort of patients in Austria and simulate the addition of oral bempedoic acid and ezetimibe to estimate the proportion of patients reaching goals.

METHODS

Patients at high or very high cardiovascular risk on lipid-lowering treatments (excluding proprotein convertase subtilisin/kexin type 9 inhibitors) from the Austrian cohort of the observational SANTORINI study were included using specific criteria. For patients not at their risk-based goals at baseline, addition of ezetimibe (if not already received) and subsequently bempedoic acid was simulated using a Monte Carlo simulation.

RESULTS

A cohort of patients (N = 144) with a mean low-density lipoprotein cholesterol of 76.4 mg/dL, with 94% (n = 135) on statins and 24% (n = 35) on ezetimibe monotherapy or in combination, were used in the simulation. Only 36% of patients were at goal (n = 52). Sequential simulation of ezetimibe (where applicable) and bempedoic acid increased the proportion of patients at goal to 69% (n = 100), with a decrease in the mean low-density lipoprotein cholesterol from 76.4 mg/dL at baseline to 57.7 mg/dL overall.

CONCLUSIONS

The SANTORINI real-world data in Austria suggest that a proportion of high and very high-risk patients remain below the guideline-recommended low-density lipoprotein cholesterol goals. Optimising use of oral ezetimibe and bempedoic acid after statins in the lipid-lowering pathway could result in substantially more patients attaining low-density lipoprotein cholesterol goals, likely with additional health benefits.

Short-term toll-like receptor 9 inhibition leads to left ventricular wall thinning after myocardial infarction

AIMS

Ischaemia-reperfusion injury (IRI) following myocardial infarction remains a challenging topic in acute cardiac care and consecutively arising heart failure represents a severe long-term consequence. The extent of neutrophil infiltration and neutrophil-mediated cellular damage are thought to be aggravating factors enhancing primary tissue injury. Toll-like receptor 9 was found to be involved in neutrophil activation as well as chemotaxis and may represent a target in modulating IRI, aspects we aimed to illuminate by pharmacological inhibition of the receptor.

METHODS AND RESULTS

Forty-nine male adult Sprague-Dawley rats were used. IRI was induced by occlusion of the left coronary artery and subsequent snare removal after 30 min. Oligonucleotide (ODN) 2088, a toll-like receptor 9 (TLR9) antagonist, control-ODN, or DNase, were administered at the time of reperfusion and over 24 h via a mini-osmotic pump. The hearts were harvested 24 h or 4 weeks after left coronary artery occlusion and immunohistochemical staining was performed. Echocardiography was done after 1 and 4 weeks to determine ventricular function. Inhibition of TLR9 by ODN 2088 led to left ventricular wall thinning (P = 0.003) in association with drastically enhanced neutrophil infiltration (P = 0.005) and increased markers of tissue damage. Additionally, an up-regulation of the chemotactic receptor CXCR2 (P = 0.046) was found after TLR9 inhibition. No such effects were observed in control-ODN or DNase-treated animals. We did not observe changes in monocyte content or subset distribution, hinting towards neutrophils as the primary mediators of the exerted tissue injury.

CONCLUSIONS

Our data indicate a TLR9-dependent, negative regulation of neutrophil infiltration. Blockage of TLR9 appears to prevent the down-regulation of CXCR2, followed by an uncontrolled migration of neutrophils towards the area of infarction and the exertion of disproportional tissue injury resulting in potential aneurysm formation. In comparison with previous studies conducted in TLR^-/- mice, we deliberately chose a transient pharmacological inhibition of TLR9 to highlight effects occurring in the first 24 h following IRI.

Staphylococcus aureus extracellular adherence protein (Eap) reduces immune cell phenotype in developing but not in established atherosclerotic lesions

Atherosclerosis is a chronic, inflammatory disease of the vessel wall where triggered immune cells bind to inflamed endothelium, extravasate and sustain local inflammation. Leukocyte adhesion and extravasation are mediated by adhesion molecules expressed by activated endothelial cells, like intercellular adhesion molecule 1 (ICAM-1). Extracellular adherence protein (Eap) from Staphylococcus aureus binds to a plethora of extracellular matrix proteins, including ICAM-1 and its ligands macrophage-1 antigen (Mac-1, αMβ2) and lymphocyte function-associated antigen 1 (LFA-1, αLβ2), thereby disrupting the interaction between leukocytes and endothelial cells. We aimed to use Eap to inhibit the interaction of leukocytes with activated endothelial cells in settings of developing and established atherosclerosis in apolipoprotein E (ApoE) deficient mice on high-fat diet. In developing atherosclerosis, Eap treatment reduced circulating platelet-neutrophil aggregates as well as infiltration of T cells and neutrophils into the growing plaque, accompanied by reduced formation of neutrophil extracellular traps (NETs). However, plaque size did not change. Intervention treatment with Eap of already established plaques did not result in cellular or morphological plaque changes, whereas T cell infiltration was increased and thereby again modulated by Eap. We conclude that although Eap leads to cellular changes in developing plaques, clinical implications might be limited as patients are usually treated at a more advanced stage of disease progression. Hence, usage of Eap might be an interesting mechanistic tool for cellular infiltration during plaque development in basic research but not a clinical target.

Interleukin-4 receptor alpha signaling regulates monocyte homeostasis

Interleukin‐4 (IL‐4) and its receptors (IL‐4R) promote the proliferation and polarization of macrophages. However, it is unknown if IL‐4R also influences monocyte homeostasis and if steady state IL‐4 levels are sufficient to affect monocytes. Employing full IL‐4 receptor alpha knockout mice (IL‐4Rα^−/−) and mice with a myeloid‐specific deletion of IL‐4Rα (IL‐4Rα^f/f LysM^cre), we show that IL‐4 acts as a homeostatic factor regulating circulating monocyte numbers. In the absence of IL‐4Rα, murine monocytes in blood were reduced by 50% without altering monocytopoiesis in the bone marrow. This reduction was accompanied by a decrease in monocyte‐derived inflammatory cytokines in the plasma. RNA sequencing analysis and immunohistochemical staining of splenic monocytes revealed changes in mRNA and protein levels of anti‐apoptotic factors including BIRC6 in IL‐4Rα^−/− knockout animals. Furthermore, assessment of monocyte lifespan in vivo measuring BrdU⁺ cells revealed that the lifespan of circulating monocytes was reduced by 55% in IL‐4Rα^−/− mice, whereas subcutaneously applied IL‐4 prolonged it by 75%. Treatment of human monocytes with IL‐4 reduced the amount of dying monocytes in vitro. Furthermore, IL‐4 stimulation reduced the phosphorylation of proteins involved in the apoptosis pathway, including the phosphorylation of the NFκBp65 protein. In a cohort of human patients, serum IL‐4 levels were significantly associated with monocyte counts. In a sterile peritonitis model, reduced monocyte counts resulted in an attenuated recruitment of monocytes upon inflammatory stimulation in IL‐4Rα^f/f LysM^cre mice without changes in overall migratory function. Thus, we identified a homeostatic role of IL‐4Rα in regulating the lifespan of monocytes in vivo.

Basic mechanisms in cardiogenic shock: part 2 - biomarkers and treatment options

Cardiogenic shock mortality rates remain high despite significant advances in cardiovascular medicine and the widespread uptake of mechanical circulatory support systems. Except for early invasive angiography and percutaneous coronary intervention of the infarct-related artery, all other widely used therapeutic measures are based on low-quality evidence. The grim prognosis and lack of high-quality data warrant further action. Within Part 2 of this two-part educational review on basic mechanisms in cardiogenic shock, we aimed to highlight the current status of translating our understanding of the pathophysiology of cardiogenic shock into clinical practice. We summarize the current status of biomarker research in risk stratification and therapy guidance. In addition, we summarized the current status of translating the findings from bench-, bedside, and biomarker studies into treatment options. Several large randomized controlled trials (RCTs) are underway, providing a huge opportunity to study contemporary cardiogenic shock patients. Finally, we call for translational, homogenous, biomarker-based, international RCTs testing novel treatment approaches to improve the outcome of our patients.

Basic mechanisms in cardiogenic shock: part 1-definition and pathophysiology

Cardiogenic shock mortality rates remain high despite significant advances in cardiovascular medicine and the widespread uptake of mechanical circulatory support systems. Except for early invasive angiography and percutaneous coronary intervention of the infarct-related artery, the most widely used therapeutic measures are based on low-quality evidence. The grim prognosis and lack of high-quality data warrant further action. Part 1 of this two-part educational review defines cardiogenic shock and discusses current treatment strategies. In addition, we summarize current knowledge on basic mechanisms in the pathophysiology of cardiogenic shock, focusing on inflammation and microvascular disturbances, which may ultimately be translated into diagnostic or therapeutic approaches to improve the outcome of our patients.

Quantitative and Functional Assessment of the Influence of Routinely Used Cryopreservation Media on Mononuclear Leukocytes for Medical Research

Quantitative and functional analysis of mononuclear leukocyte populations is an invaluable tool to understand the role of the immune system in the pathogenesis of a disease. Cryopreservation of mononuclear cells (MNCs) is routinely used to guarantee similar experimental conditions. Immune cells react differently to cryopreservation, and populations and functions of immune cells change during the process of freeze–thawing. To allow for a setup that preserves cell number and function optimally, we tested four different cryopreservation media. MNCs from 15 human individuals were analyzed. Before freezing and after thawing, the distribution of leukocytes was quantified by flow cytometry. Cultured cells were stimulated using lipopolysaccharide, and their immune response was quantified by flow cytometry, quantitative polymerase chain reaction (qPCR), and enzyme-linked immunosorbent assay (ELISA). Ultimately, the performance of the cryopreservation media was ranked. Cell recovery and viability were different between the media. Cryopreservation led to changes in the relative number of monocytes, T cells, B cells, and their subsets. The inflammatory response of MNCs was altered by cryopreservation, enhancing the basal production of inflammatory cytokines. Different cryopreservation media induce biases, which needs to be considered when designing a study relying on cryopreservation. Here, we provide an overview of four different cryopreservation media for choosing the optimal medium for a specific task.

Soluble neprilysin and survival in critically ill patients

Background

Critically ill patients admitted to an intensive care unit (ICU) exhibit a high mortality rate irrespective of the initial cause of hospitalization. Neprilysin, a neutral endopeptidase degrading an array of vasoactive peptides became a drug target within the treatment of heart failure with reduced ejection fraction. The aim of this study was to analyse whether circulating levels of neprilysin at ICU admission are associated with 30 day mortality.

Methods and results

In this single‐centre prospective observational study, 222 consecutive patients admitted to a tertiary ICU at a university hospital were included. Blood was drawn at admission and soluble neprilysin levels were measured using ELISA. In the total cohort, soluble neprilysin levels did not differ according to survival status after 30 days as well as type of admission. However, in patients after surgery or heart valve intervention, 30 day survivors exhibited significantly lower circulating neprilysin levels as compared to those who died within 30 days (660.2, IQR: 156.4–2512.5 pg/mL vs. 6532.6, IQR: 1840.1–10 000.0 pg/mL; P = 0.02). Soluble neprilysin predicted mortality independently from age, gender, and commonly used scores of risk‐prediction (EuroSCORE II, STS‐score, and SAPS II score). Additionally, soluble neprilysin was markedly elevated in patients with sepsis and septic shock (P < 0.05).

Conclusion

At the time of ICU admission, circulating levels of neprilysin independently predicted 30 day mortality in patients following cardiac surgery or heart valve intervention, but not in critically ill medical patients. Furthermore, patients suffering from sepsis and septic shock displayed significantly increased circulating neprilysin levels.

OUP accepted manuscript

Tachyarrhythmias are common complications of critically ill patients treated on intensive care units. Landiolol is an ultra-short acting beta-blocker with a very high beta1-selectivity. Therefore, landiolol effectively reduces heart rate with only minimal negative effects on blood pressure and inotropy. This article describes two cases of successful treatment of supraventricular and ventricular tachycardias with landiolol in critically ill patients.

Innate Immune Training with Bacterial Extracts Enhances Lung Macrophage Recruitment to Protect from Betacoronavirus Infection

Training of the innate immune system with orally ingested bacterial extracts was demonstrated to have beneficial effects on infection clearance and disease outcome. The aim of our study was to identify cellular and molecular processes responsible for these immunological benefits. We used a murine coronavirus (MCoV) A59 mouse model treated with the immune activating bacterial extract Broncho-Vaxom (BV) OM-85. Tissue samples were analysed with qPCR, RNA sequencing, histology, and flow cytometry. After BV OM-85 treatment, interstitial macrophages accumulated in lung tissue leading to a faster response of type I interferon (IFN) signalling after MCoV infection resulting in overall lung tissue protection. Moreover, RNA sequencing showed that lung tissue from mice receiving BV OM-85 resembled an intermediate stage between healthy and viral infected lung tissue at day 4, indicating a faster return to normal tissue homoeostasis. The pharmacologic effect was mimicked by adoptively transferring naive lung macrophages into lungs from recipient mice before virus infection. The beneficial effect of BV OM-85 was abolished when inhibiting initial type I IFN signalling. Overall, our data suggest that BV OM-85 enhances lung macrophages allowing for a faster IFN response towards a viral challenge as part of the oral-induced innate immune system training.

Pharmacological inhibition of fatty acid oxidation reduces atherosclerosis progression by suppression of macrophage NLRP3 inflammasome activation

BACKGROUND

Inflammation is a key process during atherosclerotic lesion development and propagation. Recent evidence showed clearly that especially the inhibition of interleukin (IL)-1β reduced atherosclerotic adverse events in human patients. Fatty acid oxidation (FAO) was previously demonstrated to interact with the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) pathway which is required for mature IL-1β secretion. To understand possible anti-inflammatory properties of FAO inhibition, we tested the effect of pharmacological FAO inhibition using the inhibitor for long-chain 3-ketoacyl coenzyme A thiolase trimetazidine on atherosclerotic plaque development and inflammation.

EXPERIMENTAL APPROACH

The effect of FAO inhibition was determined in LDL-R^-/- male mice on a C57/BL6 background. In vitro effects of trimetazidine treatment were analyzed in human umbilical vein endothelial cells and human monocyte derived macrophages.

KEY RESULTS

We were able to demonstrate that inhibition of FAO reduced atherosclerotic plaque growth. We did not find direct anti-inflammatory properties of trimetazidine in endothelial cells or macrophages in vitro. However, we found that the activation of the NLRP3 system and the secretion of IL-1β were significantly reduced in macrophages after FAO inhibition. These results were confirmed in atherosclerotic lesions of mice treated with trimetazidine as they showed a significant reduction of IL-1β and cleaved caspase-1 in the atherosclerotic lesion as well as of IL-1β and IL-18 in the circulation.

CONCLUSION

Overall, we therefore suggest that the main mechanism of reducing inflammation of trimetazidine and FAO inhibition is the reduction of the NLRP-3 activation leading to reduced levels of the proinflammatory cytokine IL-1β.

Circulating levels of proprotein convertase subtilisin/kexin type 9 (PCSK9) are associated with monocyte subsets in patients with stable coronary artery disease

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): FWF

Background and aims

Proprotein convertase subtilisin/kexin type-9 (PCSK9) is an enzyme promoting the degradation of low-density lipoprotein receptors (LDL-R) in hepatocytes. Inhibition of PCSK9 has emerged as a novel target for lipid-lowering therapy. Monocytes are crucially involved in the pathogenesis of atherosclerosis and can be divided into three subsets. The aim of this study was to examine whether circulating levels of PCSK9 are associated with monocyte subsets.

Methods

We included 69 patients with stable coronary artery disease. PCSK9 levels were measured and monocyte subsets were assessed by flow cytometry and divided into classical monocytes (CD14++CD16-; CM), intermediate monocytes (CD14++CD16+; IM) and non-classical monocytes (CD14 + CD16++; NCM).

Results

Mean age was 64 years and 80% of patients were male. Patients on statin treatment (n = 55) showed higher PCSK9-levels (245.4 (206.0-305.5) ng/mL) as opposed to those without statin treatment (186.1 (162.3-275.4) ng/mL; p = 0.05). In patients on statin treatment, CM correlated with circulating PCSK9 levels (R = 0.29; p = 0.04), while NCM showed an inverse correlation with PCSK9 levels (R=-0.33; p = 0.02). Patients with PCSK9 levels above the median showed a significantly higher proportion of CM as compared to patients with PCSK-9 below the median (83.5 IQR 79.2-86.7 vs. 80.4, IQR 76.5-85.2%; p = 0.05). Conversely, PCSK9 levels &gt;median were associated with a significantly lower proportion of NCM as compared to those with PCSK9 &lt;median (10.2, IQR 7.3-14.6 vs. 14.3, IQR 10.9-18.7%; p = 0.02). In contrast, IM showed no association with PCSK-9 levels.

Conclusions

We hereby provide a novel link between PCSK9 regulation, innate immunity and atherosclerotic disease in statin-treated patients.

Circulating levels of proprotein convertase subtilisin/kexin type 9 (PCSK9) are associated with monocyte subsets in patients with stable coronary artery disease

BACKGROUND

Proprotein convertase subtilisin/kexin type-9 (PCSK9) is an enzyme promoting the degradation of low-density lipoprotein receptors (LDL-R) in hepatocytes. Inhibition of PCSK9 has emerged as a novel target for lipid-lowering therapy. Monocytes are crucially involved in the pathogenesis of atherosclerosis and can be divided into three subsets.

OBJECTIVE

The aim of this study was to examine whether circulating levels of PCSK9 are associated with monocyte subsets.

METHODS

We included 69 patients with stable coronary artery disease. PCSK9 levels were measured and monocyte subsets were assessed by flow cytometry and divided into classical monocytes (CD14++CD16-; CM), intermediate monocytes (CD14++CD16+; IM) and non-classical monocytes (CD14+CD16++; NCM).

RESULTS

Mean age was 64 years and 80% of patients were male. Patients on statin treatment (n = 55) showed higher PCSK9-levels (245.4 (206.0-305.5) ng/mL) as opposed to those without statin treatment (186.1 (162.3-275.4) ng/mL; p = 0.05). In patients on statin treatment, CM correlated with circulating PCSK9 levels (R = 0.29; p = 0.04), while NCM showed an inverse correlation with PCSK9 levels (R = -0.33; p = 0.02). Patients with PCSK9 levels above the median showed a significantly higher proportion of CM as compared to patients with PCSK9 below the median (83.5 IQR 79.2-86.7 vs. 80.4, IQR 76.5-85.2%; p = 0.05). Conversely, PCSK9 levels >median were associated with a significantly lower proportion of NCM as compared to those with PCSK9 <median (10.2, IQR 7.3-14.6 vs. 14.3, IQR 10.9-18.7%; p = 0.02). In contrast, IM showed no association with PCSK9 levels.

CONCLUSIONS

We hereby provide a novel link between PCSK9 regulation, innate immunity and atherosclerotic disease in statin-treated patients.

Implementation of clinical practices and pathways optimizing ACS patients lipid management: Focus on eight European initiatives

Post-acute coronary syndrome (ACS) patients are at very high cardiovascular risk. Despite current guidelines strongly recommend to reduce LDL-C levels and initiation of high-intensity statins as early as possible in patients admitted with an ACS, less than half of ACS patients receive a high intensity statin, and a high percentage of has LDL-C well above the goal despite therapy. There are multiple reasons for that, including physician lack of guideline adherence, patient lack of compliance with treatment, and lack of standardized procedures. Furthermore, although the prevalence of familial hypercholesterolemia is higher among patients with ACS, this condition remains poorly estimated. To fill these gaps, some European countries have launched local initiatives for the in-hospital and post-discharge ACS patient lipid management. It appears that ensuring optimal therapy during hospitalization and dedicated follow-up protocols results in a significant improvement of lipid levels in these very high risk patients, which may translate into a reduced risk of recurrent future events.

Alternative activation of human macrophages enhances tissue factor expression and production of extracellular vesicles

Macrophages are versatile cells that can be polarized by the tissue environment to fulfill required needs. Proinflammatory polarization is associated with increased tissue degradation and propagation of inflammation whereas alternative polarization within a Th2 cytokine environment is associated with wound healing and angiogenesis. To understand whether polarization of macrophages can lead to a procoagulant macrophage subset we polarized human monocyte-derived macrophages to proinflammatory and alternative activation states. Alternative polarization with interleukin-4 and interleukin-13 led to a macrophage phenotype characterized by increased tissue factor (TF) production and release and by an increase in extracellular vesicle production. In addition, TF activity was enhanced in extracellular vesicles of alternatively polarized macrophages. This TF induction was dependent on signal transducer and activator of transcription- 6 signaling and poly ADP ribose polymerase activity. In contrast to monocytes, human macrophages did not show increased TF expression upon stimulation with lipopolysaccharide and interferon-γ. Previous polarization to either a proinflammatory or an alternative activation subset did not change the subsequent stimulation of TF. The inability of proinflammatory activated macrophages to respond to lipopolysaccharide and interferon- γ with an increase in TF production seemed to be due to an increase in TF promoter methylation and was reversible when these macrophages were treated with a demethylating agent. In conclusion, we provide evidence that proinflammatory polarization of macrophages does not lead to enhanced procoagulatory function, whereas alternative polarization of macrophages leads to an increased expression of TF and increased production of TF-bearing extracellular vesicles by these cells suggesting a procoagulatory phenotype of alternatively polarized macrophages.

Death is associated to the type of drug-eluting stent in patients with left ventricular dysfunction and elevated natriuretic peptide levels

As advanced heart failure (HF) with elevated NT-proBNP is characterized by an activated coagulation system, coronary events clinically noticed as sudden or HF death may be more common after treatment with first- compared to newer-generation DES. Our study evaluates (1) if patients with left ventricular dysfunction (LVSD) who underwent percutaneous coronary intervention have a better survival with first- or newer-generation DES, and (2) if the survival benefit is predicted by NT-proBNP. Our observational study evaluated patients with LVSD who were registered in the coronary catheter laboratory database of the Medical University of Vienna. Multivariate Cox regression analyses tested an interaction in the risk of death between those with lower or elevated NT-proBNP levels and the stent-generation. The relative risk of newer- compared to first-generation DES as reference was calculated for patients with low and elevated NT-proBNP levels. In 340 patients (178 newer- and 162 first-generation DES) stent-generation and NT-proBNP were independent predictors of death. When the stent-generation*NTproBNP interaction was forced into a Cox regression model, this term independently predicted death. The relative risk of first- compared to newer-generation DES was similar in patients with lower NT-proBNP (HR 1.02, 95% CI 0.95–1.10, p = 0.560), but was higher in patients with elevated NT-proBNP (HR 1.06, 95% CI 1.01–1.10, p = 0.020). Death is associated to stent-generation. NT-proBNP is a predictor for the stent generation used: elevated levels demonstrated a higher mortality risk when using first- compared to newer-generation DES, while lower levels showed a similar risk when using either DES-generation.

Effects of Nicorandil on Inflammation, Apoptosis and Atherosclerotic Plaque Progression

Nicorandil, a balanced vasodilator, is used in the second-line therapy of angina pectoris. In this study, we aimed to illuminate the effects of nicorandil on inflammation, apoptosis, and atherosclerotic plaque progression. Twenty-five LDL-R -/- mice were fed a high-fat diet for 14 weeks. After 6 weeks mice were randomly allocated to treatment with nicorandil (10 mg/kg/day) or tap water. Nicorandil treatment led to a more stable plaque phenotype, displaying an increased thickness of the fibrous cap (p = 0.014), a significant reduction in cholesterol clefts (p = 0.045), and enhanced smooth muscle cell content (p = 0.009). In endothelial cells nicorandil did not reduce the induction of adhesion molecules or proinflammatory cytokines. In H₂O₂ challenged endothelial cells, pretreatment with nicorandil significantly reduced the percentage of late apoptotic/necrotic cells (p = 0.016) and the ratio of apoptotic to living cells (p = 0.036). Atherosclerotic lesions of animals treated with nicorandil exhibited a significantly decreased content of cleaved caspase-3 (p = 0.034), lower numbers of apoptotic nuclei (p = 0.040), and reduced 8-oxogunanine staining (p = 0.039), demonstrating a stabilizing effect of nicorandil in established atherosclerotic lesions. We suggest that nicorandil has a positive effect on atherosclerotic plaque stabilization by reducing apoptosis.

Biomarkers of coagulation and fibrinolysis in acute myocardial infarction: a joint position paper of the Association for Acute CardioVascular Care and the European Society of Cardiology Working Group on Thrombosis

The formation of a thrombus in an epicardial artery may result in an acute myocardial infarction (AMI). Despite major advances in acute treatment using network approaches to allocate patients to timely reperfusion and optimal antithrombotic treatment, patients remain at high risk for thrombotic complications. Ongoing activation of the coagulation system as well as thrombin-mediated platelet activation may both play a crucial role in this context. Whether measurement of circulating biomarkers of coagulation and fibrinolysis could be useful for risk stratification in secondary prevention is currently not fully understood. In addition, measurement of such biomarkers could be helpful to identify thrombus formation as the leading mechanism for AMI. The introduction of biomarkers of myocardial injury such as high-sensitivity cardiac troponins made rule-out of AMI even more precise. However, elevated markers of myocardial injury cannot provide proof of a type 1 AMI, let alone thrombus formation. The combined measurement of markers of myocardial injury with biomarkers reflecting ongoing thrombus formation might be helpful for the fast and correct diagnosis of an atherothrombotic type 1 AMI. This position paper gives an overview of the current knowledge and possible role of biomarkers of coagulation and fibrinolysis for the diagnosis of AMI, risk stratification, and individualized treatment strategies in patients with AMI.

Interdependence of VA-ECMO output, pulmonary congestion and outcome after cardiac surgery

BACKGROUND

Venoarterial-extracorporeal membrane oxygenation (VA-ECMO) is a life-saving method for patients with low-output failure after cardiac surgery. However, VA-ECMO therapy may increase left ventricular afterload due to retrograde blood flow in the aorta, which may lead to progression of pulmonary congestion. We examined the predictive value of pulmonary congestion in patients that need VA-ECMO support after cardiovascular surgery.

METHODS

We enrolled a total of 266 adult patients undergoing VA-ECMO support following cardiovascular surgery at a university-affiliated tertiary care centre into our single-center registry. Pulmonary edema was assessed on bedside chest X rays at day 0, 3, 5 after VA-ECMO implantation.

RESULTS

Median age was 65 (57-72) years, 69% of patients were male and 30-day survival was 63%. At ICU-admission 20% of patients had mild, 54% had moderate and 26% showed severe pulmonary congestion. Pulmonary congestion at day 0 was not associated with outcome (adjusted HR 1.31; 95%-CI 0.89-1.93;P = 0.18), whereas pulmonary congestion at day 3 (adj. HR 2.81; 95%-CI 1.76-4.46;P<0.001) and day 5 (adj. HR 3.01;95%-CI 1.84-4.93;P<0.001) was significantly associated with survival. Linear regression revealed that out of left ventricular function, cardiac output, central venous saturation, maximum dobutamine and norepinephrine dose as well as fluid balance solely ECMO rotation was associated with the evolution of pulmonary congestion (P = 0.007).

CONCLUSIONS

Pulmonary edema three and five days after ECMO implantation are associated with poor survival. Interestingly, a high VA-ECMO output was the most important determinant of worsening pulmonary congestion within the first five days.

Monocyte subsets predict mortality after cardiac arrest

After successful cardiopulmonary resuscitation (CPR), many patients show signs of an overactive immune activation. Monocytes are a heterogeneous cell population that can be distinguished into 3 subsets by flow cytometry (classical monocytes [CM: CD14⁺⁺CD16^‐], intermediate monocytes [IM: CD14⁺⁺CD16⁺CCR2⁺] and non‐classical monocytes [NCM: CD14⁺CD16⁺⁺CCR2^‐]). Fifty‐three patients admitted to the medical intensive care unit (ICU) after cardiac arrest were included. Blood was taken on admission and after 72 h. The primary endpoint of this study was survival at 6 months and the secondary endpoint was neurological outcome as determined by cerebral performance category (CPC)‐score at 6 months. Median age was 64.5 (49.8‐74.3) years and 75.5% were male. Six‐month mortality was 50.9% and survival with good neurological outcome was 37.7%. Monocyte subset distribution upon admission to the ICU did not differ according to survival. Seventy‐two hours after admission, patients who died within 6 months showed a higher percentage of the pro‐inflammatory subset of IM (8.3% [3.8‐14.6]% vs. 4.1% [1.5–8.2]%; P = 0.025), and a lower percentage of CM (87.5% [79.9–89.0]% vs. 90.8% [85.9–92.7]%; P = 0.036) as compared to survivors. In addition, IM were predictive of outcome independent of time to ROSC and witnessed cardiac arrest, and correlated with CPC‐score at 6 months (R = 0.32; P = 0.043). These findings suggest a possible role of the innate immune system in the pathophysiology of post cardiac arrest syndrome.

The ISTH DIC score predicts outcome in non-septic patients admitted to a cardiovascular intensive care unit

BACKGROUND

The International Society of Thrombosis and Haemostasis (ISTH) disseminated intravascular coagulation (DIC) score is widely used to predict mortality in critically ill - typically septic - patients. The objective of this study was to investigate whether the ISTH DIC-2001 and DIC-2018 score can be used to predict the 30-day mortality in non-septic patients in an intensive care unit (ICU).

METHODS

In this single-center, prospective observational study we included all patients ≥18 years of age who were admitted to a medical ICU with a focus on cardiovascular diseases between August 2012 and 2013. The DIC-2001 and DIC-2018 scores were calculated on admission (DIC-2001-0h and DIC-2018-0h) and 72 hours thereafter (DIC-2001-72h and DIC-2018-72h) and were classified as overt when ≥ 5 for DIC-2001 and ≥ 4 for DIC-2018.

RESULTS

A total of 233 patients were included in this study. Excluding septic patients and patients after routine surgery/procedures, we calculated the DIC score for 167 patients (32.4% female; median age 64.9 years). Overt DIC-2001-0h, DIC-2018-0h and overt DIC-2001-72h scores were associated with a significantly higher 30-day mortality rate (52.9% vs. 25.0%, 46.2% vs 21.2%, and 57.1% vs. 23.7%; p < 0.04). The DIC-2001 scores and the DIC-2018-0h score significantly predicted the 30-day mortality.

CONCLUSION

This study suggests that the DIC score may be applied to non-septic ICU populations, and indicates that it is a useful tool for mortality prediction, regardless of the underlying disease.

Neutrophil Extracellular Trap Degradation by Differently Polarized Macrophage Subsets

Supplemental Digital Content is available in the text.

Macrophages are immune cells, capable to remodel the extracellular matrix, which can harbor extracellular DNA incorporated into neutrophil extracellular traps (NETs). To study the breakdown of NETs we studied the capability of macrophage subsets to degrade these structures in vitro and in vivo in a murine thrombosis model. Furthermore, we analyzed human abdominal aortic aneurysm samples in support of our in vitro and in vivo results.

Epinephrine treatment but not time to ROSC is associated with intestinal injury in patients with cardiac arrest

AIM

Current guidelines suggest the use of epinephrine in patients with cardiac arrest (CA). However, evidence for increased survival in good neurological condition is lacking. In experimental settings, epinephrine-induced impairment of microvascular flow was shown. The aim of our study was to analyze the association between epinephrine treatment and intestinal injury in patients after CA.

METHODS

We have included 52 patients with return of spontaneous circulation (ROSC) after CA admitted to our medical intensive care unit (ICU). Blood was taken on admission and levels of circulating intestinal fatty acid binding protein (iFABP) were analyzed.

RESULTS

Patients were 64 (49.8-73.8) years old and predominantly male (76.9%). After six months, 50% of patients died and 38.5% of patients had a cerebral performance category (CPC)-score of 1-2. iFABP levels were lower in survivors (234 IQR 90-399 pg/mL) as compared to non-survivors (283, IQR 86-11500 pg/mL; p < 0.05). Plasma levels of iFABP were not associated with time to ROSC but correlated with epinephrine-dose (R = 0.32; p < 0.05). 40% of patients receiving ≥3 mg of epinephrine as compared to 10.5% of patients treated with <3 mg (p < 0.05) developed iFABP plasma levels >1500 pg/mL, which was associated with dramatically increased mortality (HR4.87, 95%CI 1.95-12.1; p < 0.001). iFABP levels predicted mortality independent from time to ROSC and the disease severity score SAPS II. In contrast to mortality, iFABP plasma levels were not associated with neurological outcome.

CONCLUSIONS

In this small, single centre study, cumulative dose of epinephrine used in cardiac arrest patients was associated with an increase in biomarker indicative of intestinal injury and 6-month mortality.

The adipokine vaspin is associated with decreased coronary in-stent restenosis in vivo and inhibits migration of human coronary smooth muscle cells in vitro

BACKGROUND

Percutaneous coronary intervention represents the most important treatment modality of coronary artery stenosis. In-stent restenosis (ISR) is still a limitation for the long-term outcome despite the introduction of drug eluting stents. It has been shown that adipokines directly influence vessel wall homeostasis by influencing the function of endothelial cells and arterial smooth muscle cells. Visceral adipose tissue-derived serpin vaspin was recently identified as a member of serine protease inhibitor family and serveral studies could demonstrate a relation to metabolic diseases. The aim of this study was to investigate a role of vaspin in the development of in-stent restenosis in vivo and on migration of smooth muscle cells and endothelial cells in vitro.

METHODS

We studied 85 patients with stable coronary artery disease who underwent elective and successful PCI with implatation of drug eluting stents. Blood samples were taken directly before PCI. Vaspin plasma levels were measured by specific ELISA. ISR was evaluated eight months later by coronary angiography. Human coronary artery smooth muscle cells (HCASMC) and human umbilical vein endothelial cells (HUVEC) migration was analyzed by an in-vitro migration assay with different concentrations (0.004ng/mL up to 40ng/mL) of vaspin as well as by an scratch assay. For proliferation an impedance measurement with specialiced E-Plates was performed.

RESULTS

During the follow up period, 14 patients developed ISR. Patients with ISR had significantly lower vaspin plasma levels compared to patients without ISR (0.213 ng/ml vs 0.382 ng/ml; p = 0.001). In patients with plasma vaspin levels above 1.35 ng/ml we could not observe any restenosis. There was also a significant correlation of plasma vaspin levels and late lumen loss in the stented coronary segments. Further we could demonstrate that vaspin nearly abolishes serum induced migration of HCASMC (100% vs. 9%; p<0.001) in a biphasic manner but not migration of HUVEC. Proliferation of HCASMC and HUVEC was not modulated by vaspin treatment.

CONCLUSION

We were able to show that the adipokine vaspin selectively inhibits human coronary SMC migration in vitro and has no effect on HUVEC migration. Vaspin had no effect on proliferation of HUVEC which is an important process of the healing of the stented vessel. In addition, the occurrence of ISR after PCI with implantation of drug eluting stents was significantly associated with low vaspin plasma levels before intervention. Determination of vaspin plasma levels before PCI might be helpful in the identification of patients with high risk for development of ISR after stent implantation. In addition, the selective effects of vaspin on smooth muscle cell migration could potentially be used to reduce ISR without inhibition of re-endothelialization of the stented segment.

Neutrophil extracellular traps and monocyte subsets at the culprit lesion site of myocardial infarction patients

Neutrophils release their chromatin into the extracellular space upon activation. These web-like structures are called neutrophil extracellular traps (NETs) and have potent prothrombotic and proinflammatory properties. In ST-elevation myocardial infarction (STEMI), NETs correlate with increased infarct size. The interplay of neutrophils and monocytes impacts cardiac remodeling. Monocyte subsets are classified as classical, intermediate and non-classical monocytes. In the present study, in vitro stimulation with NETs led to an increase of intermediate monocytes and reduced expression of CX3CR1 in all subsets. Intermediate monocytes have been associated with poor outcome, while non-classical CX3CR1-positive monocytes could have reparative function after STEMI. We characterized monocyte subsets and NET markers at the culprit lesion site of STEMI patients (n = 91). NET surrogate markers were increased and correlated with larger infarct size and with fewer non-classical monocytes. Intermediate and especially non-classical monocytes were increased at the culprit site compared to the femoral site. Low CX3CR1 expression of monocytes correlated with high NET markers and increased infarct size. In this translational system, causality cannot be proven. However, our data suggest that NETs interfere with monocytic differentiation and receptor expression, presumably promoting a subset shift at the culprit lesion site. Reduced monocyte CX3CR1 expression may compromise myocardial salvage.

P789TLR-4 expression predicts mortality in patients with acute heart failure

Background

Inflammation is regarded as an important trigger for disease progression in heart failure (HF) and activation of the inflammatory system was implicated in the pathophysiology of acute heart failure (AHF).

Toll-like receptors (TLRs) play an important role in acute inflammatory processes in critically ill patients by binding to pathogen associated molecular patterns (PAMP) and danger associated molecular patterns (DAMP). However, it is not known whether the expression patterns of TLRs on neutrophils and monocytes are associated with outcome in patients with severe AHF requiring intensive care unit (ICU) admission.

The aim of this prospective, observational study was to analyze whether TLR-expression on monocytes or neutrophils is associated with 30-day survival in patients with severe AHF.

Methods

We included 84 patients with severe AHF admitted to a cardiac ICU. Blood was taken at admission and mean fluorescence activity (MFI) of TLR-2, TLR-4 and TLR-9 on monocytes and neutrophils was analyzed by flow cytometry.

Results

Median age was 64 (IQR 48–74) years and 76.2% of patients were male. Median NT-proBNP was 4941 (IQR 1298–12273) pg/mL and 30-day mortality was 33.3%. TLR-4 expression on monocytes in survivors (740 IQR 694–854) was significantly lower than in non-survivors (871 IQR 723–979; p<0.05). TLR-2 and TLR-9 expression on monocytes and TLR expression on neutrophils was not associated with survival. TLR-4 expression on monocytes was significantly associated with survival independent of age, sex, creatinine and NT-proBNP levels.

Conclusion

Monocyte TLR-4 expression predicts mortality in patients admitted to a cardiac ICU for severe acute heart failure. This suggests that activation of the innate immune system by TLR-binding of DAMPS may play a significant role in critically ill acute heart failure patients.

Growth differentiation factor-15 predicts poor survival after cardiac arrest

BACKGROUND

Early prognostication in post-cardiac arrest (CA) patients remains challenging and biomarkers have evolved as helpful tools in risk assessment. The stress-response cytokine growth differentiation factor-15 (GDF-15) is dramatically up-regulated during various kinds of tissue injury and predicts outcome in many pathological conditions. We aimed to assess the predictive value of circulating GDF-15 in post-CA patients.

METHODS

This prospective observational study included 128 consecutive patients (median age 60.3 years, 75.8% male) with return of spontaneous circulation after in- or out-of-hospital CA who were treated at a tertiary university hospital. GDF-15 serum levels were determined at admission.

RESULTS

A total of 52 patients (40.6%) died during the 6-month follow-up. Median GDF-15 levels were significantly lower in survivors (1601 ng/L (interquartile range: 1114-2983 ng/L) than in non-survivors (3172 ng/L (1927-8340 ng/L); p < 0.001). GDF-15 levels were also significantly lower in patients with favourable neurological 6-month outcome (cerebral performance category (CPC) 1-2) than in those with poor neurological outcome (CPC 3-5; p < 0.001). GDF-15 significantly predicted 6-month mortality in univariate Cox regression analysis (hazard ratio (HR) per 1-standard deviation increase 1.76 [95% confidence interval (CI) 1.35-2.31; p < 0.001] and remained significant after multivariable adjustment (HR 1.57 [95% CI 1.19-2.07; p = 0.001]). Subgroup analysis revealed that the association between GDF-15 and 6-month outcome was present both in patients with in- and out-of-hospital CA.

CONCLUSIONS

GDF-15 predicts poor survival and neurological outcome in post-CA patients. GDF-15 may reflect the extent of hypoxic injury to the brain and other organs and might help to improve early risk stratification after CA.

Protease-Activated Receptors 1 and 3 are Differentially Expressed on Human Monocyte Subsets and are Upregulated by Lipopolysaccharide Ex Vivo and In Vivo

Monocytes are activated in inflammatory conditions via a variety of cytokine receptors as well as in a procoagulatory setting through thrombin, acting upon protease-activated receptors (PARs). This study investigated the expression pattern of PAR1 and PAR3 on human monocyte subsets. Furthermore, a possible regulation of the expression of PAR1 and PAR3 in these cells by inflammatory activation were studied. CD16⁺ monocytes showed significantly higher levels of PAR1 and PAR3 as compared with CD16^- monocytes. Ex vivo treatment of whole blood with lipopolysaccharide (LPS) increased PAR1 and PAR3 messenger ribonucleic acid (mRNA) in human monocytes. In addition, increase of PAR1 was seen in all three subsets upon LPS treatment, whereas PAR3 increased significantly only in CD16^- monocytes and nonclassical CD16⁺ monocytes. Protein levels of PAR1 and PAR3 significantly increased on monocytes in vivo in human endotoxemia 1 hour after LPS infusion. PAR1 increased significantly in CD16^- monocytes and nonclassical CD16⁺ monocytes. In this in vivo model, PAR3 was also significantly elevated in CD16^- monocytes and increased slightly albeit not significantly in CD16⁺ monocytes. Endotoxemia increased plasminogen activator inhibitor-1 (PAI-1) and tissue factor (TF) expression in monocytes in humans. Pretreatment of healthy volunteers with the PAR1 antagonist vorapaxar blocked the increase in PAI-1 but not the increase in TF. We here provide new evidence for a critical role for monocytes as cellular mediators that contribute to the activation of coagulation in diseases characterized by an inflammatory state.

Release of mitochondrial DNA is associated with mortality in severe acute heart failure

BACKGROUND

Inflammation is regarded as an important trigger for disease progression in heart failure. Particularly in severe acute heart failure, tissue hypoxia may lead to cellular damage and the release of intracellular mitochondrial DNA, which acts as an activator of the immune system due to its resemblance to bacterial DNA. It may therefore serve as a mediator of disease progression. The aim of this study was to determine circulating levels of mitochondrial DNA and its association with mortality in patients with heart failure in different presentations.

METHODS

Plasma levels of circulating mitochondrial DNA were measured in 90 consecutive patients with severe acute heart failure admitted to our medical intensive care unit as well as 109 consecutive chronic heart failure patients.

RESULTS

In patients admitted to our medical intensive care unit (median age 64 (49-74) years, median NT-pro-brain natriuretic peptide 4986 (1525-23,842) pg/mL, 30-day survival 64.4%), mitochondrial DNA levels were significantly higher in patients who died within 30 days after intensive care unit admission, and patients with plasma levels of mitochondrial DNA in the highest quartile had a 3.4-fold increased risk (P=0.002) of dying independent of renal function, vasopressor use and NT-pro-brain natriuretic peptide, troponin T, lactate levels or CardShock and acute physiology and chronic health evaluation II score. However, mitochondrial DNA did not provide incremental prognostic accuracy on top of the current gold standard acute physiology and chronic health evaluation II. Patients with severe acute heart failure showed significantly higher mitochondrial DNA levels (P<0.005) as compared to patients with chronic heart failure. In these patients, mitochondrial DNA levels were associated with the New York Heart Association functional class but were not associated with outcome.

CONCLUSIONS

The release of mitochondrial DNA into the circulation is associated with mortality in patients with severe acute heart failure but not in patients with chronic heart failure. The release of mitochondrial DNA may therefore play a role within the pathophysiology of acute heart failure, which warrants further research. However, the use of mitochondrial DNA as a biomarker for risk stratification in these patients is of limited utility.

N-terminal pro-brain natriuretic peptide and high-sensitivity troponin T exhibit additive prognostic value for the outcome of critically ill patients

BACKGROUND

Patients treated at medical intensive care units suffer from various pathologies and often present with elevated troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Both markers may reflect different forms of cardiac involvement in critical illness. Therefore, the aim of our study was to examine the synergistic prognostic potential of NT-proBNP and high-sensitivity TnT (hs)TnT in unselected critically ill patients.

METHODS

We included all consecutive patients admitted to our intensive care unit within one year, excluding those suffering from acute myocardial infarction or undergoing cardiac surgery and measured NT-proBNP and TnT plasma levels on the day of admission and 72 hours thereafter.

RESULTS

Of the included 148 patients, 52% were male, mean age was of 64.2 ± 16.8 years and 30-day mortality was 33.2%. Non-survivors showed significantly higher NT-proBNP and TnT plasma levels as compared with survivors (p<0.01). An elevation of both markers exhibited an additive effect on mortality, as those with both NT-proBNP and TnT levels above the median had a 30-day mortality rate of 51.0%, while those with both markers below the median had a 16.7% mortality rate (hazard ratio 3.7). These findings were independent of demographic and clinical parameters (p<0.05).

CONCLUSIONS

Our findings regarding the individual predictive properties of NT-proBNP and TnT are in line with literature. However, we were able to highlight that they exhibit additive prognostic potential which exceeds their individual value. This might be attributed to a difference in underlying pathomechanisms and an assessment of synergistic risk factors.

Clopidogrel in Critically Ill Patients

Only limited data are available regarding the treatment of critically ill patients with clopidogrel. This trial investigated the effects and the drug concentrations of the cytochrome P450 (CYP450) activated prodrug clopidogrel (n = 43) and the half‐life of the similarly metabolized pantoprazole (n = 16) in critically ill patients. ADP‐induced aggregometry in whole blood classified 74% (95% confidence intervals 59–87%) of critically ill patients as poor responders (n = 43), and 65% (49–79%) responded poorly according to the vasodilator‐stimulated phosphoprotein phosphorylation (VASP‐P) assay. Although the plasma levels of clopidogrel active metabolite normally exceed the inactive prodrug ∼30‐fold, the parent drug levels even exceeded those of the metabolite 2‐fold in critically ill patients. The half‐life of pantoprazole was several‐fold longer in these patients compared with reference populations. The inverse ratio of prodrug/active metabolite indicates insufficient metabolization of clopidogrel, which is independently confirmed by the ∼5‐fold increase in half‐life of pantoprazole. Thus, high‐risk patients may benefit from treatment with alternative platelet inhibitors.

PAI-1 (Plasminogen Activator Inhibitor-1) Expression Renders Alternatively Activated Human Macrophages Proteolytically Quiescent

OBJECTIVE

Macrophages are versatile immune cells capable of polarizing into functional subsets depending on environmental stimulation. In atherosclerotic lesions, proinflammatory polarized macrophages are associated with symptomatic plaques, whereas Th2 (T-helper cell type 2) cytokine-polarized macrophages are inversely related with disease progression. To establish a functional cause for these observations, we analyzed extracellular matrix degradation phenotypes in polarized macrophages.

APPROACH AND RESULTS

We provide evidence that proinflammatory polarized macrophages rely on membrane-bound proteases including MMP-14 (matrix metalloproteinase-14) and the serine protease uPA (urokinase plasminogen activator) together with its receptor uPAR for extracellular matrix degradation. In contrast, Th2 cytokine alternatively primed macrophages do not show different proteolytic activity in comparison to unpolarized macrophages and lack increased localization of MMP-14 and uPA receptor to the cell membrane. Nonetheless, they express the highest amount of the serine protease uPA. However, uPA activity is blocked by similarly increased expression of its inhibitor PAI-1 (plasminogen activator inhibitor 1). When inhibiting PAI-1 or when analyzing macrophages deficient in PAI-1, Th2 cytokine-polarized macrophages display the same matrix degradation capability as proinflammatory-primed macrophages. Within atherosclerotic lesions, macrophages positive for the alternative activation marker CD206 express high levels of PAI-1. In addition, to test changed tissue remodeling capacities of alternatively activated macrophages, we used a bleomycin lung injury model in mice reconstituted with PAI-1^-/- bone marrow. These results supported an enhanced remodeling phenotype displayed by increased fibrosis and elevated MMP activity in the lung after PAI-1 loss.

CONCLUSIONS

We were able to demonstrate matrix degradation dependent on membrane-bound proteases in proinflammatory stimulated macrophages and a forced proteolytical quiescence in alternatively polarized macrophages by the expression of PAI-1.

Prasugrel in critically ill patients

While prasugrel is indicated for the treatment of myocardial infarction, its effects in the most severely affected patients requiring intensive care is unknown, so that we measured the antiplatelet effects and sparse pharmacokinetics of prasugrel in critically ill patients. Twenty-three patients admitted to medical intensive care units, who were treated with 10 mg prasugrel once daily, were included in this prospective trial. Critically ill patients responded poorly to daily prasugrel treatment: adenosine diphosphate (ADP)-induced aggregation in whole blood classified 65 % (95 % confidence intervals (CI) 43-84 %) of patients as having high on treatment platelet reactivity, platelet function under high shear rates even 74 % (95 %CI 52-90 %). There was only limited additional inhibition provided 2 hours after the next dose of prasugrel. In contrast, insufficient inhibition of the target was only seen in 26 % (95 %CI 10-48 %) of patients as measured by the vasodilator-stimulated phosphoprotein phosphorylation (VASP-P) assay. Low effective plasma levels of prasugrel active metabolite were measured at trough [0.5 (quartiles 0.5-1.1) ng/ml at baseline], and 2 hours after intake [5.7 (3.8-9.8) ng/ml], but showed coefficients of variation of ~70 %. In sum, inhibition of platelet aggregation by prasugrel is not uniform but highly variable in critically ill patients, similar to clopidogrel in a general population. The pharmacokinetic measurements indicate that poor absorption/metabolism of prasugrel may partly contribute while inflammation induced heightened intrinsic platelet reactivity may also play a role.

Acetylsalicylic acid in critically ill patients: a cross-sectional and a randomized trial

BACKGROUND

Despite decades of clinical use, the pharmacokinetics and the effects of acetylsalicylic acid (ASA) in critically ill patients remain ill-defined. We aimed to investigate the pharmacokinetics and the effects of different ASA formulations during critical illness.

DESIGN

A cross-sectional study and a randomized, parallel-group trial were performed. Critically ill patients under chronic oral ASA treatment (100 mg enteric-coated) were screened for high 'on-treatment' platelet reactivity (HTPR) according to arachidonic acid-induced whole-blood aggregometry. Thirty patients with HTPR were randomized to receive 100 mg ASA intravenously, 100 mg enteric-coated ASA bid (bis in die) or 81 mg chewable ASA (n = 10 per group). Serum thromboxane B2 (TXB2) levels, ASA and salicylic acid levels were quantified.

RESULTS

Of 66 patients, 85% (95% confidence intervals 74-93%) had HTPR. Compared to baseline infusion of 100 mg, ASA significantly reduced platelet aggregation after 24 h to median 80% (Quartiles: 66-84%). Intake of 81 mg chewable ASA significantly reduced platelet aggregation to 75% (54-86%) after four hours, but increased it to 117% after 24 h (81-163%). Treatment with 100 mg enteric-coated ASA bid decreased platelet aggregation after 24 h to median 56% (52-113%). Baseline TXB2 levels were median 0·35 ng/mL (0·07-0·94). Infusion of ASA or intake of 100 mg ASA bid reduced TXB2 levels to 0·07-0·18 ng/mL after 24 h, respectively. Chewable ASA reduced TXB2 levels only transiently. Pharmacokinetic analysis revealed highly variable absorption patterns of oral ASA formulations.

CONCLUSION

There is a very high prevalence of HTPR in critically ill patients on peroral ASA therapy, caused by an incomplete suppression of TXB2 and/or by impaired absorption of ASA.

Anti-thrombotic and pro-fibrinolytic effects of levosimendan in human endothelial cells in vitro

AIMS

Levosimendan is an inodilator for the treatment of acute decompensated heart failure (HF). Data from clinical studies suggest that levosimendan is particularly effective in HF due to myocardial infarction. After acute revascularization, no reflow-phenomenon is a common complication that may lead to pump failure and cardiogenic shock. Our aim was to examine whether levosimendan interferes with the pro-thrombotic phenotype of activated endothelial cells in vitro.

METHODS

Human heart microvascular endothelial cells (HHMEC) and human umbilical vein endothelial cells (HUVEC) were treated with interleukin-1β (IL-1β) (200U/mL) or thrombin (5U/mL) and co-treated with or without levosimendan (0.1-10μM) for 2-24h. In addition, flow experiments were performed. Effects on plasminogen activator inhibitor-1 (PAI-1) and tissue factor (TF) expression and activity were measured by rt-PCR, specific ELISA and flow cytometry.

RESULTS

Treatment with IL-1β or thrombin significantly increased the expression of PAI-1 and TF in endothelial cells. Co-treatment with levosimendan strongly attenuated the effects of IL-1β and thrombin on PAI-1 and TF mRNA by up to 50% and 45%, in a dose- and time-dependent manner. Similar results were obtained under flow conditions. Furthermore, co-treatment with levosimendan dampened the antigen production of PAI-1 and the surface expression of TF by 35% and 45%, respectively. Additionally, levosimendan diminished both TF and PAI-1 activity.

CONCLUSION

Levosimendan down-regulates the expression of the pro-thrombotic and anti-fibrinolytic biomolecules TF and PAI-1 in activated human endothelial cells. Our findings may, at least in part, explain some of the beneficial effects of levosimendan after myocardial reperfusion.

Copeptin Predicts Mortality in Critically Ill Patients

Background

Critically ill patients admitted to a medical intensive care unit exhibit a high mortality rate irrespective of the cause of admission. Besides its role in fluid and electrolyte balance, vasopressin has been described as a stress hormone. Copeptin, the C-terminal portion of provasopressin mirrors vasopressin levels and has been described as a reliable biomarker for the individual’s stress level and was associated with outcome in various disease entities. The aim of this study was to analyze whether circulating levels of copeptin at ICU admission are associated with 30-day mortality.

Methods

In this single-center prospective observational study including 225 consecutive patients admitted to a tertiary medical ICU at a university hospital, blood was taken at ICU admission and copeptin levels were measured using a commercially available automated sandwich immunofluorescent assay.

Results

Median acute physiology and chronic health evaluation II score was 20 and 30-day mortality was 25%. Median copeptin admission levels were significantly higher in non-survivors as compared with survivors (77.6 IQR 30.7–179.3 pmol/L versus 45.6 IQR 19.6–109.6 pmol/L; p = 0.025). Patients with serum levels of copeptin in the third tertile at admission had a 2.4-fold (95% CI 1.2–4.6; p = 0.01) increased mortality risk as compared to patients in the first tertile. When analyzing patients according to cause of admission, copeptin was only predictive of 30-day mortality in patients admitted due to medical causes as opposed to those admitted after cardiac surgery, as medical patients with levels of copeptin in the highest tertile had a 3.3-fold (95% CI 1.66.8, p = 0.002) risk of dying independent from APACHE II score, primary diagnosis, vasopressor use and need for mechanical ventilation.

Conclusion

Circulating levels of copeptin at ICU admission independently predict 30-day mortality in patients admitted to a medical ICU.

Monocyte subset distribution is associated with mortality in critically ill patients

Although patients admitted to an intensive care unit (ICU) suffer from various pathologies, many develop a systemic inflammatory response syndrome (SIRS). As key regulators of innate immunity, monocytes may be crucially involved in SIRS development. Monocytes can be distinguished into three subsets: Classical monocytes (CD14⁺⁺CD16^-; CM), non-classical monocytes (CD14⁺CD16⁺⁺CCR2^-; NCM) and intermediate monocytes (CD14⁺⁺CD16⁺CCR2⁺; IM). The aim of this prospective, observational study was to analyse whether monocyte subset distribution is associated with 30-day survival in critically ill patients. A total of 195 consecutive patients admitted to a cardiac ICU at a tertiary-care centre were enrolled, blood was taken at admission and after 72 hours and monocyte subset distribution was analysed. Mean APACHE II score was 19.5 ± 8.1 and 30-day mortality was 25.4 %. At admission, NCM were significantly lower in non-survivors as compared to survivors [2.7 (0.4-5.5) vs 4.2 (1.6-7.5)%; p=0.012] whereas CM and IM did not differ according to 30-day survival. In contrast, 72 hours after admission, monocyte subset distribution shifted towards an increased proportion of IM [8.2 (3.9-13.2) vs 4.2 (2.3-7.9)%; p=0.003] with a concomitant decrease of CM [86.9 (78.6-89.2) vs 89.6 (84.9-93.1)%; p=0.02] in non-survivors vs survivors, respectively. NCM at day 3 were not associated with death at 30 days. These results were independent from age, gender, CRP, APACHE II score and primary diagnosis. In conclusion, circulating monocyte subsets are associated with 30-day mortality in critically ill patients. The innate immune system as reflected by monocyte subset distribution may play a major role in ICU outcome despite varying admittance pathologies.

Differential in vivo activation of monocyte subsets during low-grade inflammation through experimental endotoxemia in humans

Human monocytes are a heterogeneous cell population, which can be divided into a classical (CD14++CD16−), a non-classical (CD14+CD16+), and an intermediate (CD14++CD16+) subset. We hypothesized that low-grade inflammation may differentially affect monocyte subsets. We used a human lipopolysaccharide (LPS) infusion model to mimic low-grade inflammation to identify, which monocyte subsets are preferentially activated under these conditions. Monocyte subsets were identified by staining for CD14 and CD16, activation status of monocytes was analyzed by staining for CD11b and a novel in situ mRNA hybridization approach to detect IL-6 and IL-8 specific mRNA at the single-cell level by flow cytometry. After LPS challenge, cell numbers of monocyte subsets dropped after 2 h with cell numbers recovering after 6 h. Distribution of monocyte subsets was skewed dramatically towards the intermediate subset after 24 h. Furthermore, intermediate monocytes displayed the largest increase of CD11b expression after 2 h. Finally, IL-6 and IL-8 mRNA levels increased in intermediate and non-classical monocytes after 6 h whereas these mRNA levels in classical monocytes changed only marginally. In conclusion, our data indicates that the main responding subset of monocytes to standardized low-grade inflammation induced by LPS in humans is the CD14++CD16+ intermediate subset followed by the CD14+CD16+ non-classical monocyte subset. Circulating classical monocytes showed comparably less reaction to LPS challenge in vivo.