Implementation of high sensitivity troponin into routine clinical practice - results of the extended CARdiac MArkers guideline uptake in Europe group (CARMAGUE) survey

BACKGROUND

Measurement of cardiac troponin (cTn) by a high sensitivity method is now the recommended strategy for the detection of myocardial injury. An international survey was undertaken to assess how this has been implemented.

METHODS

A questionnaire based around 14 domains on cardiac biomarkers was distributed electronically with the aid of professional societies accessed by a web link within the invitation. Results were returned electronically then extracted into a relational database for analysis.

RESULTS

Responses were obtained from 663 laboratories across 76 countries ranging from 1 to 69 largest country. The majority of responses (79.6%) came from the European area. Responses were grouped into broad geographic areas for analysis. Most responses came from hospitals providing a local and regional service of which the majority provided angioplasty. cTn measurement was the dominant biomarker. The majority of laboratories include creatine kinase (CK) in their cardiac profile and approximately 50% also offer the MB isoenzyme of CK. The majority of laboratories (91.9%) measure cTn by a high sensitivity method. Sex specific reference ranges were typically implemented for cardiac troponin I but not for cardiac troponin T. The preferred unit of measurement was nanograms/L. A structured decision-making pathway utilising high sensitivity cTn measurement was used by 83.3% of laboratories who responded. Single sample rule out is common but the majority used serial sampling strategy based on measurement on admission and three hours.

CONCLUSIONS

Measurement of cTn by a high sensitivity method is now well established internationally, the use of rapid diagnostic protocols lags behind.

The multidimensional value of natriuretic peptides in heart failure, integrating laboratory and clinical aspects

Natriuretic peptides (NP) play an essential role in heart failure (HF) regulation, and their measurement has improved diagnostic and prognostic accuracy. Clinical symptoms and objective measurements, such as NP levels, should be included in the HF definition to render it more reliable and consistent among observers, hospitals, and healthcare systems. BNP and NT-proBNP are reasonable surrogates for cardiac disease, and their measurement is critical to early diagnosis and risk stratification of HF patients. NPs should be measured in all patients presenting with dyspnea or other symptoms suggestive of HF to facilitate early diagnosis and risk stratification. Both BNP and NT-proBNP are currently used for guided HF management and display comparable diagnostic and prognostic accuracy. Standardized cutoffs for each NP assay are essential for data comparison. The value of NP testing is recognized at various levels, including patient empowerment and education, analytical and operational issues, clinical HF management, and cost-effectiveness.

New reference limits for cardiac troponin T and N-terminal b-type natriuretic propeptide in elders

BACKGROUND AND AIMS

Our aim was to define reference limits for cardiac troponin T (cTnT) and N-terminal pro B-type natriuretic peptide (proBNP) that would better reflect their concentrations in older people. In addition, the incidence of acute myocardial infarctions (AMIs) was studied using these reference limits in an older population with and without previous heart diseases.

MATERIALS AND METHODS

A population-based study with a ten-year follow-up. The reference population was formed by 763 individuals aged over 64 years, with no diagnoses of heart or kidney diseases.

RESULTS

There was a significant increase in cTnT and proBNP concentrations with age. The 99 % reference limits for cTnT were 25 ng/L, 28 ng/l, 38 ng/l, and 71 ng/l for men in five-year-intervals starting from 64 to 69 years to 80 years and older, and 18 ng/L, 22 ng/l, 26 ng/l, and 52 ng/L for women, respectively. The 97.5 % reference limits for proBNP were 272 ng/L, 287 ng/l, 373 ng/l and 686 ng/L for men, and 341 ng/L, 377 ng/l, 471 ng/l, and 794 ng/L for women, respectively. Elevated proBNP was statistically significantly associated with future AMIs in subjects with and without a previous heart disease.

CONCLUSIONS

Age-specific reference limits for cTnT and proBNP are needed to better evaluate cardiac symptoms.

Paraproteins and electrolyte assays: exclusion effect and effect of paraprotein elimination

Paraproteins are a potential source of error for electrolyte analyses. The exclusion effect itself causes a discrepancy between direct and indirect ion selective electrode assays (dISE and iISE, respectively). We tested the applicability of different pretreatment methods and the difference of dISE and iISE with paraprotein-rich samples. We analysed chloride (Cl-), potassium (K+), and sodium (Na+) on 46 samples with paraproteins up to 73 g/L. We compared pretreatment methods of preheating, precipitation, and filtration to the native sample. All induced a statistically significant difference (p-value <0.05). Clinically significant difference was induced by precipitation for all analytes, and filtration for Cl- and Na+, but for none by preheating. The difference in electrolyte measurements with either dISE or iISE on native samples was explained by total protein concentration (TP). There was a statistically significant difference in all electrolyte measurements. On average, there was a clinically significant difference in Na + but not in Cl- and K + measurements. Paraprotein concentration (PP) or heavy chain class did not induce a statistically significant effect. The regression analysis and comparison to the theoretical exclusion effect supported the conclusion that TP is the only explanatory factor in the difference between dISE and iISE. We conclude that preheating is a suitable pretreatment method for all the studied analytes. Precipitation is not valid for any of them, and filtration can be considered only for K+. Because the difference between dISE and iISE was explained by the exclusion effect caused by TP, dISE is the more suitable method to analyse paraprotein-rich samples.

Serum caspase-cleaved cytokeratin-18 fragment as a prognostic biomarker in hematological patients with febrile neutropenia

The study aim was to determine the benefit of the measurement of serum caspase-cleaved cytokeratin-18 (CK-18) fragment as a prognostic marker of febrile neutropenia (FN) in hematological patients. The study population consisted of 86 consecutive patients with FN who received intensive chemotherapy for hematological malignancy at the adult hematology ward of Kuopio University Hospital. Twenty-three patients (27%) had acute myeloid leukemia, and 63 patients (73%) were autologous stem cell transplant recipients. Serum caspase-cleaved CK-18 fragment M30, C-reactive protein (CRP) and procalcitonin (PCT) were measured at the onset of FN (d0), on day 1 (d1), and on day 2 (d2). Eight patients (9%) developed severe sepsis, including three patients with septic shock. Eighteen patients (21%) had a blood culture-positive infection. Serum CK-18 fragment peaked on the first day after fever onset in patients with severe sepsis. Higher CK-18 level was associated with severe sepsis, intensive care unit treatment, and fatal outcome, but not with blood culture positivity. In ROC curve analysis, d1 serum CK-18 fragment predicted severe sepsis with an area under the curve (AUC) of 0.767, CRP with an AUC of 0.764, and PCT with an AUC of 0.731. On d2, the best predictive capacity was observed for CRP with an AUC of 0.832. The optimal cutoff of caspase-cleaved CK-18 fragment M30 for predicting severe sepsis was 205 U/L on d1. In hematological patients, serum CK-18 fragment was found to be a potential prognostic marker of severe sepsis at early stages of FN.

Tau, S100B and NSE as Blood Biomarkers in Acute Cerebrovascular Events

BACKGROUND/AIM

We aimed to analyze the diagnostic value of total tau (T-tau), S-100 calcium-binding protein B (S100B) and neuron-specific enolase (NSE) as blood-based biomarkers in acute ischemic stroke (AIS) or transient ischemic attack (TIA), and their correlation with symptom severity, infarct size, etiology and outcome.

PATIENTS AND METHODS

A total of 102 patients with stroke and 35 with TIA were analyzed. Subacute (63.8±50.1 h) plasma T-tau was measured with the single-molecule array (Simoa) method and NSE and S100B were evaluated for comparison. We evaluated biomarkers associations with: (i) diagnosis of AIS or TIA, (ii) cerebral infarction volume in the brain computed tomography, (iii) stroke etiology, (iv) clinical stroke severity and (iv) functional outcome after three months.

RESULTS

T-tau was higher in patients with stroke [1.0 pg/ml (IQR=0.3-2.2)] than with TIA [0.5 pg/ml (IQR=0.2-1.0), p=0.02]. The levels of S100B were also increased in stroke [0.082 μg/l (IQR=0.049-0.157)] patients compared to TIA patients [0.045 μg/l (IQR=0.03-0.073), p<0.001]. However, when the results were adjusted for confounders, significance was lost. Serum levels of NSE among patients with AIS [11.85 μg/l (IQR=9.30-16.14)] compared to those with TIA [10.96 μg/l (IQR=7.98-15.33), p=0.30] were equal. T-tau and S100B concentrations significantly correlated with cerebral infarction volume (r=0.412, p<0.001) and (r=0.597, p<0.001), also after corrections (p<0.001). mRS scores at three-month follow-up correlated with T-tau (r=0.248, p=0.016) and S100B concentrations (r=0.205, p=0.045).

CONCLUSION

For the diagnosis of TIA vs. AIS, blood T-tau and S100B concentrations discriminated only modestly. Additionally, groups were not separable after measuring of T-tau and S100B levels in the blood. T-tau and S100B concentrations correlated with the infarct size, but were not alone predictive for functional outcome at 3 months.

How Well Do Laboratories Adhere to Recommended Guidelines for Cardiac Biomarkers Management in Europe? The CArdiac MARker Guideline Uptake in Europe (CAMARGUE) Study of the European Federation of Laboratory Medicine Task Group on Cardiac Markers

BACKGROUND

The CARdiac MARker Guideline Uptake in Europe (CAMARGUE) program is a multi-country audit of the use of cardiac biomarkers in routine clinical practice.

METHODS

An email link to a web-based questionnaire of 30 multiple-choice questions was distributed via the professional societies in Europe.

RESULTS

374 questionnaires were returned from 39 countries, the majority of which were in northern Europe with a response rate of 8.2%-42.0%. The majority of the respondents were from hospitals with proportionately more responses from central hospitals than district hospitals. Cardiac troponin was the preferred cardiac biomarker, evenly split between cardiac troponin T (cTnT) and cardiac troponin I (cTnI). Aspartate transaminase and lactate dehydrogenase are no longer offered as cardiac biomarkers. Creatine kinase, creatine kinase MB isoenzyme, and myoglobin continue to be offered as part of the cardiac biomarker profile in approximately on 50% of respondents. There is widespread utilization of high sensitivity (hs) troponin assays. The majority of cTnT users measure hs-cTnT. 29.5% of laboratories measure cTnI by a non-hs method but there has been substantial conversion to hs-cTnI. The majority of respondents used ng/L and use the 99th percentile as the upper reference limit (71.9% of respondents). A range of diagnostic protocols are in use.

CONCLUSIONS

There is widespread utilization of hs troponin methods. A significant minority do not use the 99th percentile as recommended and there is, as yet, little uptake of very rapid diagnostic strategies. Education of laboratory professionals and clinicians remains a priority.

Quantifying atherogenic lipoproteins for lipid-lowering strategies: consensus-based recommendations from EAS and EFLM

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently addressed present and future challenges in the laboratory diagnostics of atherogenic lipoproteins. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), LDL cholesterol (LDLC), and calculated non-HDLC (=total - HDLC) constitute the primary lipid panel for estimating risk of atherosclerotic cardiovascular disease (ASCVD) and can be measured in the nonfasting state. LDLC is the primary target of lipid-lowering therapies. For on-treatment follow-up, LDLC shall be measured or calculated by the same method to attenuate errors in treatment decisions due to marked between-method variations. Lipoprotein(a) [Lp(a)]-cholesterol is part of measured or calculated LDLC and should be estimated at least once in all patients at risk of ASCVD, especially in those whose LDLC declines poorly upon statin treatment. Residual risk of ASCVD even under optimal LDL-lowering treatment should be also assessed by non-HDLC or apolipoprotein B (apoB), especially in patients with mild-to-moderate hypertriglyceridemia (2-10 mmol/L). Non-HDLC includes the assessment of remnant lipoprotein cholesterol and shall be reported in all standard lipid panels. Additional apoB measurement can detect elevated LDL particle (LDLP) numbers often unidentified on the basis of LDLC alone. Reference intervals of lipids, lipoproteins, and apolipoproteins are reported for European men and women aged 20-100 years. However, laboratories shall flag abnormal lipid values with reference to therapeutic decision thresholds.

A practical laboratory index to predict institutionalization and mortality - an 18-year population-based follow-up study

Background

Previously, several indexes based on a large number of clinical and laboratory tests to predict mortality and frailty have been produced. However, there is still a need for an easily applicable screening tool for every-day clinical practice.

Methods

A prospective study with 10- and 18-year follow-ups. Fourteen common laboratory tests were combined to an index. Cox regression model was used to analyse the association of the laboratory index with institutionalization and mortality.

Results

The mean age of the participants (n = 1153) was 73.6 (SD 6.8, range 64.0–100.0) years. Altogether, 151 (14.8%) and 305 (29.9%) subjects were institutionalized and 422 (36.6%) and 806 (69.9%) subjects deceased during the 10- and 18-year follow-ups, respectively. Higher LI (laboratory index) scores predicted increased mortality. Mortality rates increased as LI scores increased both in unadjusted and in age- and gender-adjusted models during both follow-ups. The LI did not significantly predict institutionalization either during the 10- or 18-year follow-ups.

Conclusions

A practical index based on routine laboratory tests can be used to predict mortality among older people. An LI could be automatically counted from routine laboratory results and thus an easily applicable screening instrument in clinical settings.

Predictive value of plasma proenkephalin and neutrophil gelatinase-associated lipocalin in acute kidney injury and mortality in cardiogenic shock

BACKGROUND

Acute kidney injury (AKI) is a frequent form of organ injury in cardiogenic shock. However, data on AKI markers such as plasma proenkephalin (P-PENK) and neutrophil gelatinase-associated lipocalin (P-NGAL) in cardiogenic shock populations are lacking. The objective of this study was to assess the ability of P-PENK and P-NGAL to predict acute kidney injury and mortality in cardiogenic shock.

RESULTS

P-PENK and P-NGAL were measured at different time points between baseline and 48 h in 154 patients from the prospective CardShock study. The outcomes assessed were AKI defined by an increase in creatinine within 48 h and all-cause 90-day mortality. Mean age was 66 years and 26% were women. Baseline levels of P-PENK and P-NGAL (median [interquartile range]) were 99 (71-150) pmol/mL and 138 (84-214) ng/mL. P-PENK > 84.8 pmol/mL and P-NGAL > 104 ng/mL at baseline were identified as optimal cut-offs for AKI prediction and independently associated with AKI (adjusted HRs 2.2 [95% CI 1.1-4.4, p = 0.03] and 2.8 [95% CI 1.2-6.5, p = 0.01], respectively). P-PENK and P-NGAL levels at baseline were also associated with 90-day mortality. For patients with oliguria < 0.5 mL/kg/h for > 6 h before study enrollment, 90-day mortality differed significantly between patients with low and high P-PENK/P-NGAL at baseline (5% vs. 68%, p < 0.001). However, the biomarkers provided best discrimination for mortality when measured at 24 h. Identified cut-offs of P-PENK_24h > 105.7 pmol/L and P-NGAL_24h > 151 ng/mL had unadjusted hazard ratios of 5.6 (95% CI 3.1-10.7, p < 0.001) and 5.2 (95% CI 2.8-9.8, p < 0.001) for 90-day mortality. The association remained significant despite adjustments with AKI and two risk scores for mortality in cardiogenic shock.

CONCLUSIONS

High levels of P-PENK and P-NGAL at baseline were independently associated with AKI in cardiogenic shock patients. Furthermore, oliguria before study inclusion was associated with worse outcomes only if combined with high baseline levels of P-PENK or P-NGAL. High levels of both P-PENK and P-NGAL at 24 h were found to be strong and independent predictors of 90-day mortality.

TRIAL REGISTRATION

NCT01374867 at www.clinicaltrials.gov , registered 16 Jun 2011-retrospectively registered.

Febrile neutropenia in patients with acute myeloid leukemia: Outcome in relation to qSOFA score, C-reactive protein, and blood culture findings

OBJECTIVES

To evaluate quick Sequential Organ Failure Assessment (qSOFA) score during febrile neutropenia (FN) in adult patients receiving intensive chemotherapy for acute myeloid leukemia (AML).

METHODS

qSOFA score, as well as the association of qSOFA score with ICU admission, infectious mortality, blood culture findings, and C-reactive protein (CRP) measurements during FN were assessed among 125 adult AML patients with 355 FN periods receiving intensive chemotherapy in a tertiary care hospital from November 2006 to December 2018.

RESULTS

The multivariate model for qSOFA score ≥ 2 included CRP ≥ 150 mg/L on d0-2 [OR 2.9 (95% CI 1.1-7.3), P = .026], Gram-negative bacteremia [OR 2.7 (95% CI 1.1-6.9), P = .034], and treatment according to AML-2003 vs more recent protocols [OR 2.7 (95% CI 1.0-7.4), P = .047]. Age or gender did not gain significance in the model. qSOFA score ≥ 2 was associated with ICU treatment and infectious mortality during FN with sensitivity and specificity of 0.700 and 0.979, and 1.000 and 0.971, respectively.

CONCLUSION

qSOFA offers a useful tool to evaluate the risk of serious complications in AML patients during FN.

Kinetics of procalcitonin, C-reactive protein and interleukin-6 in cardiogenic shock - Insights from the CardShock study

BACKGROUND

Inflammatory responses play an important role in the pathophysiology of cardiogenic shock (CS). The aim of this study was to investigate the kinetics of procalcitonin (PCT), C-reactive protein (CRP), and interleukin-6 (IL-6) in CS and to assess their relation to clinical presentation, other biochemical variables, and prognosis.

METHODS

Levels of PCT, CRP and IL-6 were analyzed in serial plasma samples (0-120h) from 183 patients in the CardShock study. The study population was dichotomized by PCT_max ≥ and < 0.5 μg/L, and IL-6 and CRP_max above/below median.

RESULTS

PCT peaked already at 24 h [median PCT_max 0.71 μg/L (IQR 0.24-3.4)], whereas CRP peaked later between 48 and 72 h [median CRP_max 137 mg/L (59-247)]. PCT levels were significantly higher among non-survivors compared with survivors from 12 h on, as were CRP levels from 24 h on (p < 0.001). PCT_max ≥ 0.5 μg/L (60% of patients) was associated with clinical signs of systemic hypoperfusion, cardiac and renal dysfunction, acidosis, and higher levels of blood lactate, IL-6, growth-differentiation factor 15 (GDF-15), and CRP_max. Similarly, IL-6 > median was associated with clinical signs and biochemical findings of systemic hypoperfusion. PCT_max ≥ 0.5 μg/L and IL-6 > median were associated with increased 90-day mortality (50% vs. 30% and 57% vs. 22%, respectively; p < 0.01 for both), while CRP_max showed no prognostic significance. The association of inflammatory markers with clinical infections was modest.

CONCLUSIONS

Inflammatory markers are highly related to signs of systemic hypoperfusion in CS. Moreover, high PCT and IL-6 levels are associated with poor prognosis.

Plasma level of interleukin-18 and complicated course of febrile neutropenia in hematological patients after intensive chemotherapy

In search of a biomarker for complicated course of febrile neutropenia (FN), plasma IL-18 was measured in 92 hematological patients after intensive chemotherapy at the beginning of FN (days 0-3). Complicated course was defined as blood culture positivity or septic shock. IL-18 varied according to background hematological malignancy and showed an inverse correlation with leukocyte count. IL-18 was not associated with complicated course of FN, defined as blood culture positivity or septic shock, in the whole study group, but an association was observed on d1 and d2 after the onset of FN in the subgroup of autologous stem cell transplant recipients with non-Hodgkin lymphoma.

Direct Immunoassay for Free Pregnancy-Associated Plasma Protein A (PAPP-A)

Background

Pregnancy-associated plasma protein A (PAPP-A), especially in its noncomplexed form (fPAPP-A), is linked to vulnerable atherosclerotic plaques and risk of cardiac events. An assay for sensitive detection of fPAPP-A has been lacking. Our aim was to develop and validate a direct fPAPP-A assay to meet this need.

Methods

Monoclonal antibodies binding exclusively fPAPP-A were produced by immunizing mice with recombinant PAPP-A. In the optimized immunoassay, we used an fPAPP-A–specific capture antibody together with a lanthanide-chelate–labeled monoclonal antibody recognizing all PAPP-A forms. The assay was evaluated with CLSI guidelines and compared to a 2-assay subtractive fPAPP-A approach. Clinical performance was assessed with acute coronary syndrome patients.

Results

The limits of detection and quantitation were 0.4 mIU/L and 1.3 mIU/L, respectively, and the assay was linear up to 1000 mIU/L (R2 = 0.999). Both serum and heparin plasma were suitable matrices, and the complexed form of PAPP-A caused no significant interference. Correlation between the developed assay and the 2-assay approach was fair (Pearson's r = 0.819). Median concentration in healthy individuals was 1.0 mIU/L. fPAPP-A concentration was higher in patients who had myocardial infarction or died during the 1-year follow-up period than in those who did not (1.13 mIU/L vs 0.82 mIU/L, P = 0.008, model adjusted with age and sex). fPAPP-A measured with this direct assay predicted this end point as well as (follow-up 1 year) or better (30 days) than the 2-assay fPAPP-A alone or in combination with cTnI.

Conclusions

The new assay enables sensitive and reliable measurement of low cardiac-related fPAPP-A concentrations from blood samples.

Educational Recommendations on Selected Analytical and Clinical Aspects of Natriuretic Peptides with a Focus on Heart Failure: A Report from the IFCC Committee on Clinical Applications of Cardiac Bio-Markers

The IFCC Committee on Clinical Applications of Cardiac Bio-Markers (C-CB) has directives and initiatives focused on providing evidence-based educational resources to aid and improve understanding around key analytical and clinical aspects of cardiac biomarkers used in clinical practice and the research setting. As a task force, we have previously published position statements and recommendations focused on use and analytical aspects of high-sensitivity cardiac troponin assays. The current educational document is the first from the C-CB highlighting important biochemical, analytical, and clinical aspects as they relate to the natriuretic peptides (NPs), including B-type natriuretic peptide (BNP) and N-terminal pro–B-type natriuretic peptide (NT-proBNP), with a focus on heart failure.

Levels of Growth Differentiation Factor 15 and Early Mortality Risk Stratification in Cardiogenic Shock

BACKGROUND

The aim of this study was to assess the levels, kinetics, and prognostic value of growth differentiation factor 15 (GDF-15) in cardiogenic shock (CS).

METHODS AND RESULTS

Levels of GDF-15 were determined in serial plasma samples (0-120 h) from 177 CS patients in the CardShock study. Kinetics of GDF-15, its association with 90-day mortality, and incremental value for risk stratification were assessed. The median GDF-15_0h level was 9647 ng/L (IQR 4500-19,270 ng/L) and levels above median were significantly associated with acidosis, hyperlactatemia, renal dysfunction, and higher 90-day mortality (56% vs 28%, P < .001). Serial sampling showed that non-survivors had significantly higher GDF-15 levels at all time points (P < .001 for all). Furthermore, non-survivors displayed increasing and survivors declining GDF-15 levels during the first days in CS. Higher levels of GDF-15 were independently associated with mortality. A GDF-15_12h cutoff >7000 ng/L was identified as a strong predictor of death (OR 5.0; 95% CI 1.9-3.8, P = .002). Adding GDF-15_12h >7000 ng/L to the CardShock risk score improved discrimination and risk stratification for 90-day mortality.

CONCLUSIONS

GDF-15 levels are highly elevated in CS and associated with markers of systemic hypoperfusion and end-organ dysfunction. GDF-15 helps to discriminate survivors from non-survivors very early in CS.

Serum Neurofilament Light Chain Concentration Correlates with Infarct Volume but Not Prognosis in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

We studied serum neurofilaments diagnostic value in patients with acute ischemic stroke (AIS) or TIA and evaluated any correlation with symptom severity, cerebral infarction volume, aetiology, and clinical outcome.

METHODS

One hundred and thirty-six patients (101 with AIS, and 35 with TIA) were included. Acute-phase serum neurofilament light chain (sNfL) was analyzed with a novel ultrasensitive single molecule array (Simoa). Cerebral infarction volume was measured from brain computed tomography in the subacute phase (>2 days). Stroke aetiology was defined by trial of ORG 10172 in acute stroke treatment classification, severity by National Institute of Health stroke scale (NIHSS) and the degree of disability by the Modified Rankin Scale (mRS) after 90 days.

RESULTS

sNfL was markedly higher in patients with AIS (89.5 pg/mL [IQR: 44.7-195.3]) than with TIA (25.2 pg/mL [IQR: 14.6-48.0]), P= <.001), also after adjusting for age, NIHSS, and stroke volume (P= .003). In receiver operating characteristic analysis, sNfL concentration greater than or equal to 49 pg/mL proved to be the best cut-off value to differentiate between patients with stroke and those with TIA (sensitivity of 73% and specificity of 80%). sNfL concentration significantly correlated with cerebral infarction volume (r = .413, P= <.001), this association remained significant after adjusting for established predictors (P= .019). Patients with AIS due to cardioembolism or large artery atherosclerosis had the highest sNfL concentrations. NIHSS on admission (r = .343, P = <.001) and mRS scores after 3 months (r = .306, P = .004) correlated with sNfL concentration, however functional outcome 3 months after stroke was not associated with sNfL after adjusting for potential confounders.

CONCLUSIONS

Cases with stroke were distinguishable from those with TIA following the determination of sNfL in the blood samples. The presence and amount of axonal damage estimated by sNfL correlated with the final cerebral infarction volume but was not predictive of degree of disability.

MMP-10 and TIMP-1 as indicators of severe sepsis in adult hematological patients with febrile neutropenia

Commonly used indicators of sepsis are nonspecific and insufficient for predicting the course of febrile neutropenia (FN) in hematological patients. We analyzed data from 91 adult FN patients who received intensive chemotherapy for acute myeloid leukemia or autologous stem cell transplantation. Compared to patients with non-severe sepsis, patients with severe sepsis had significantly higher serum levels of tissue inhibitor of metalloproteinases-1 on the day of first occurrence of fever (day 0: 172 vs. 112 µg/L, p= .002) and for the two following days (day 1: 219 vs. 128 µg/L, p< .001; day 2: 443 vs. 128 µg/L, p= .001), and significantly higher serum levels of matrix metalloproteinase-10 on day 1 (1975 vs. 876 ng/L, p= .001) and day 2 (2020 vs. 841 ng/L, p< .001). We conclude that the measurement of these biomarkers may be useful in predicting the severity of sepsis in FN patients.

Hypoalbuminemia is a frequent marker of increased mortality in cardiogenic shock

INTRODUCTION

The prevalence of hypoalbuminemia, early changes of plasma albumin (P-Alb) levels, and their effects on mortality in cardiogenic shock are unknown.

MATERIALS AND METHODS

P-Alb was measured from serial blood samples in 178 patients from a prospective multinational study on cardiogenic shock. The association of hypoalbuminemia with clinical characteristics and course of hospital stay including treatment and procedures was assessed. The primary outcome was all-cause 90-day mortality.

RESULTS

Hypoalbuminemia (P-Alb < 34g/L) was very frequent (75%) at baseline in patients with cardiogenic shock. Patients with hypoalbuminemia had higher mortality than patients with normal albumin levels (48% vs. 23%, p = 0.004). Odds ratio for death at 90 days was 2.4 [95% CI 1.5-4.1] per 10 g/L decrease in baseline P-Alb. The association with increased mortality remained independent in regression models adjusted for clinical risk scores developed for cardiogenic shock (CardShock score adjusted odds ratio 2.0 [95% CI 1.1-3.8], IABP-SHOCK II score adjusted odds ratio 2.5 [95%CI 1.2-5.0]) and variables associated with hypoalbuminemia at baseline (adjusted odds ratio 2.9 [95%CI 1.2-7.1]). In serial measurements, albumin levels decreased at a similar rate between 0h and 72h in both survivors and nonsurvivors (ΔP-Alb -4.6 g/L vs. 5.4 g/L, p = 0.5). While the decrease was higher for patients with normal P-Alb at baseline (p<0.001 compared to patients with hypoalbuminemia at baseline), the rate of albumin decrease was not associated with outcome.

CONCLUSIONS

Hypoalbuminemia was a frequent finding early in cardiogenic shock, and P-Alb levels decreased during hospital stay. Low P-Alb at baseline was associated with mortality independently of other previously described risk factors. Thus, plasma albumin measurement should be part of the initial evaluation in patients with cardiogenic shock.

TRIAL REGISTRATION

NCT01374867 at ClinicalTrials.gov.

Cardiac troponin and natriuretic peptide analytical interferences from hemolysis and biotin: educational aids from the IFCC Committee on Cardiac Biomarkers (IFCC C-CB)

Two interferences recently brought to the forefront as patient safety issues include hemolysis (hemoglobin) and biotin (vitamin B7). The International Federation for Clinical Chemistry Committee on Cardiac Biomarkers (IFCC-CB) obtained input from a majority of cTn and NP assay manufacturers to collate information related to high-sensitivity (hs)-cTnI, hs-cTnT, contemporary, and POC cTn assays, and NP assays interferences due to hemolysis and biotin. The information contained in these tables was designed as educational tools to aid laboratory professionals and clinicians in troubleshooting cardiac biomarker analytical results that are discordant with the clinical situation.

Circulating levels of microRNA 423-5p are associated with 90 day mortality in cardiogenic shock

AIMS

The role of microRNAs has not been studied in cardiogenic shock. We examined the potential role of miR-423-5p level to predict mortality and associations of miR-423-5p with prognostic markers in cardiogenic shock.

METHODS AND RESULTS

We conducted a prospective multinational observational study enrolling consecutive cardiogenic shock patients. Blood samples were available for 179 patients at baseline to determine levels of miR-423-5p and other biomarkers. Patients were treated according to local practice. Main outcome was 90 day all-cause mortality. Median miR-423-5p level was significantly higher in 90 day non-survivors [median 0.008 arbitrary units (AU) (interquartile range 0.003-0.017) vs. 0.004 AU (0.002-0.009), P = 0.003]. miR-423-5p level above median was associated with higher lactate (median 3.7 vs. 2.4 mmol/L, P = 0.001) and alanine aminotransferase levels (median 68 vs. 35 IU/L, P < 0.001) as well as lower cardiac index (1.8 vs. 2.4, P = 0.04) and estimated glomerular filtration rate (56 vs. 70 mL/min/1.73 m² , P = 0.002). In Cox regression analysis, miR-423-5p level above median was associated with 90 day all-cause mortality independently of established risk factors of cardiogenic shock [adjusted hazard ratio 1.9 (95% confidence interval 1.2-3.2), P = 0.01].

CONCLUSIONS

In cardiogenic shock patients, above median level of miR-423-5p at baseline is associated with markers of hypoperfusion and seems to independently predict 90 day all-cause mortality.

Novel renal markers for the assessment of renal integrity in patients undergoing knee arthroplasty - a pilot study

Background

The feasibility of novel kidney injury biomarkers in consecutive patients having total knee arthroplasty with local infiltration analgesia was evaluated.

Methods

We enrolled 30 patients scheduled for elective unilateral total knee arthroplasty. Paired plasma and urine samples were taken before surgery and at 4 h, 24 h and 48 h after surgery to measure creatinine, cystatin C, neutrophil gelatinase associated lipocalin, kidney injury molecule-1, interleukin-18 and liver-type fatty acid-binding protein.

Results

At baseline, 13 subjects had normal kidney function, 15 had mild and two had moderate kidney failure evaluated by calculated glomerular filtration rate. None of the subjects had all measured novel renal markers below proposed cut-off concentrations. Altogether 28/30 subjects had one (n = 3), two (n = 7) or three (n = 18) plasma neutrophil gelatinase associated lipocalin values above normal. In seven of these 28 subjects plasma creatinine, calculated glomerular filtration rate and plasma cystatin C were within the reference values. Five subjects had a low urine output, < 0.5 mL/h, indicating transient acute kidney injury, four of these had high plasma neutrophil gelatinase associated lipocalin and one high plasma cystatin C.

Conclusions

In the present study plasma neutrophil gelatinase associated lipocalin was elevated in most subjects with total knee arthroplasty and local infiltration analgesia as a marker of possible renal proximal tubular injury. Five subjects had transient low urine output, but none developed renal deterioration requiring treatment.