Sex Hormones and Adrenal Steroids: Biological Variation Estimated Using Direct and Indirect Methods.

BACKGROUND: Biological variation (BV) data may be used to develop analytical performance specifications (APS), reference change values (RCV), and support the applicability of population reference intervals. This study estimates within-subject BV (CVI) for several endocrine biomarkers using 3 different methodological approaches. METHODS: For the direct method, 30 healthy volunteers were sampled weekly for 10 consecutive weeks. Samples were analyzed in duplicate for 17-hydroxyprogesterone (17-OHP), androstenedione, cortisol, cortisone, estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), and testosterone. A CV-ANOVA with outlier removal and a Bayesian model were applied to derive the CVI. For estradiol, FSH and LH, only the male subgroup was included. In the indirect method, using the same analytes and groups, pairs of sequential results were extracted from the laboratory information system. The total result variation for individual pairs was determined by identifying a central gaussian distribution in the ratios of the result pairs. The CVI was then estimated by removing the effect of analytical variation. RESULTS: The estimated CVI from the Bayesian model (µCVP(i)) in the total cohort was: 17-OHP, 23%; androstenedione, 20%; cortisol, 18%; cortisone, 11%; SHBG, 7.4%; testosterone, 16%; and for the sex hormones in men: estradiol, 14%; FSH, 8%; and LH, 26%. CVI-heterogeneity was present for most endocrine markers. Similar CVI data were estimated using the CV-ANOVA and the indirect method. CONCLUSIONS: Similar CVI data were obtained using 2 different direct and one indirect method. The indirect approach is a low-cost alternative ensuring implementation of CVI data applicable for local conditions.

Circulating cardiovascular biomarkers during and after preeclampsia: Crosstalk with placental function?

Cardiovascular disease (CVD) is the leading cause of death in women, yet sex-specific risk factors remain understudied. Preeclampsia and other adverse pregnancy outcomes imply an increased maternal cardiovascular risk. We hypothesized that cardiac troponin T (cTnT), N-terminal pro-Brain Natriuretic Peptide (NT-proBNP) and growth differentiation factor 15 (GDF-15) are increased in such pregnancies and correlate with markers of placental dysfunction. We also investigated these cardiovascular biomarkers 1 or 3 years postpartum. Prior to delivery, we included serum from 417 pregnant women: 55 early-onset preeclampsia (EO-PE), 63 late-onset preeclampsia (LO-PE), 30 gestational hypertension (GH) and 269 healthy controls. Postpartum, we included 341 women 1 or 3 years after delivery: 26 EO-PE, 107 LO-PE, 61 GH, and 147 healthy pregnancies. Prior to delivery, median cTnT and NT-proBNP concentrations were higher in women with EO-PE, LO-PE, or GH than in controls. Median GDF-15 was higher in EO-PE and LO-PE compared to controls. Postpartum, GDF-15 was elevated in women with previous EO-PE. Markers of placental dysfunction correlated with CVD biomarkers in pregnancy, but not postpartum. Our findings underscore the cardiovascular burden of hypertensive disorders of pregnancy and the crosstalk with placental function. The upregulation of circulating GDF-15 following early-onset preeclampsia is in line with the epidemiological excessive risk of premature CVD in this group of women. GDF-15 may be explored for targeting postpartum women with most to gain from intensified preventive follow-up for CVD.

Cardiovascular biomarkers in pregnancy with diabetes and associations to glucose control.

AIM: Cardiovascular disease (CVD) is a leading cause of death in both men and women. Type 1 and 2 diabetes mellitus (DM1 and DM2) are well-known risk factors for CVD. In addition, gestational diabetes mellitus (GDM) is a female sex-specific risk factor for CVD. Here, we measure circulating concentrations of cardiac troponin T (cTNT), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and growth differentiation factor 15 (GDF-15) during pregnancy-a window of time often referred to as a cardiovascular stress test for women. METHODS: This study utilized data from 384 pregnant women: 64 with DM1, 16 with DM2, 35 with GDM and 269 euglycemic controls. Blood was predominantly sampled within a week before delivery. Cardiovascular biomarker concentrations were measured in serum using electrochemiluminescence immunoassay. RESULT: Circulating cTnT levels were higher in women with DM1, DM2 and GDM as compared to controls, whereas NT-proBNP and GDF-15 levels were only increased in women with DM1. Glucose dysregulation, assessed by third trimester HbA1c levels, positively correlated with all three CVD biomarker levels, whereas pregestational body mass index correlated negatively with GDF-15. CONCLUSIONS: Our results support the presence of myocardial affection in women with diabetic disorders during pregnancy. Although pregestational DM1 in this study was associated with the most adverse CVD biomarker profile, women with GDM displayed an adverse cTnT profile similar to what we found in women with pregestational DM2. This supports that women with GDM should be offered long-term intensified cardiovascular follow-up and lifestyle advice following delivery, similarly to the well-established CV follow-up of women with pregestational DM.

Prognostic value of cardiac biomarkers and National Early Warning Score 2 in acute dyspnoea.

OBJECTIVE: Patients hospitalised with acute dyspnoea due to acute heart failure (AHF) have a grave prognosis, but the European Society of Cardiology guidelines recommend no system to risk stratify these patients. The prognostic value of combining National Early Warning Score (NEWS) 2 and established cardiac biomarkers is not known. METHODS: We measured high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) and calculated NEWS2 in 314 patients with acute dyspnoea within 24 hours of hospitalisation. Their prognostic merits were assessed in the total cohort and for the subgroup with AHF separately. RESULTS: The median age was 73 (quartile (Q) 1-3, 63-81) years, 48% were women and 143 patients (46%) were hospitalised with AHF. The 114 patients (36%) who died during follow-up (median 823 days, Q1-3, 471-998) had higher concentrations of hs-cTnT (62 vs 33 ng/L, p<0.001) and NT-proBNP (6995 vs 2605 ng/L, p<0.001), and higher NEWS2 (6.1 vs 4.5 points, p<0.001), compared with survivors. Patients with increased vs low NEWS2 clinical risk had higher mortality rates in adjusted analyses in the total cohort (HR 2.11, 95% CI 1.28 to 3.48) and in patients with AHF (HR 2.00, 95% CI 1.54 to 2.60). NEWS2 provided incremental prognostic information compared with biomarkers alone for the total cohort: area under the curve 0.72 vs 0.70, p=0.042, and for the subpopulation with AHF: 0.70 vs 0.67, p=0.014. CONCLUSION: NEWS2 predicts long-term mortality in patients hospitalised due to acute dyspnoea and the subgroup with AHF and provide incremental prognostic information to hs-cTnT and NT-proBNP.

Adding stress biomarkers to high-sensitivity cardiac troponin for rapid non-ST-elevation myocardial infarction rule-out protocols.

AIMS: This study tested the hypothesis that combining stress-induced biomarkers (copeptin or glucose) with high-sensitivity cardiac troponin (hs-cTn) increases diagnostic accuracy for non-ST-elevation myocardial infarction (NSTEMI) in patients presenting to the emergency department. METHODS AND RESULTS: The ability to rule-out NSTEMI for combinations of baseline hs-cTnT or hs-cTnI with copeptin or glucose was compared with the European Society of Cardiology (ESC) hs-cTnT/I-only rule-out algorithms in two independent (one Norwegian and one international multicentre) diagnostic studies. Among 959 patients (median age 64 years, 60.5% male) with suspected NSTEMI in the Norwegian cohort, 13% had NSTEMI. Adding copeptin or glucose to hs-cTnT/I as a continuous variable did not improve discrimination as quantified by the area under the curve {e.g. hs-cTnT/copeptin 0.91 [95% confidence interval (CI) 0.89-0.93] vs. hs-cTnT alone 0.91 (95% CI 0.89-0.93); hs-cTnI/copeptin 0.85 (95% CI 0.82-0.87) vs. hs-cTnI alone 0.93 (95% CI 0.91-0.95)}, nor did adding copeptin <9 mmol/L or glucose <5.6 mmol/L increase the sensitivity of the rule-out provided by hs-cTnT <5 ng/L or hs-cTnI <4 ng/L in patients presenting more than 3 h after chest pain onset (target population in the ESC-0 h-algorithm). The combination decreased rule-out efficacy significantly (both P < 0.01). These findings were confirmed among 1272 patients (median age 62 years, 69.3% male) with suspected NSTEMI in the international validation cohort, of which 20.7% had NSTEMI. A trend towards increased sensitivity for the hs-cTnT/I/copeptin combinations (97-100% vs. 91-97% for the ESC-0 h-rule-out cut-offs) was observed in the Norwegian cohort. CONCLUSION: Adding copeptin or glucose to hs-cTnT/I did not increase diagnostic performance when compared with current ESC guideline hs-cTnT/I-only 0 h-algorithms.

Biological variation of cardiac myosin-binding protein C in healthy individuals.

OBJECTIVES: Cardiac myosin-binding protein C (cMyC) is a novel biomarker of myocardial injury, with a promising role in the triage and risk stratification of patients presenting with acute cardiac disease. In this study, we assess the weekly biological variation of cMyC, to examine its potential in monitoring chronic myocardial injury, and to suggest analytical quality specification for routine use of the test in clinical practice. METHODS: Thirty healthy volunteers were included. Non-fasting samples were obtained once a week for ten consecutive weeks. Samples were tested in duplicate on the Erenna® platform by EMD Millipore Corporation. Outlying measurements and subjects were identified and excluded systematically, and homogeneity of analytical and within-subject variances was achieved before calculating the biological variability (CVI and CVG), reference change values (RCV) and index of individuality (II). RESULTS: Mean age was 38 (range, 21-64) years, and 16 participants were women (53%). The biological variation, RCV and II with 95% confidence interval (CI) were: CVA (%) 19.5 (17.8-21.6), CVI (%) 17.8 (14.8-21.0), CVG (%) 66.9 (50.4-109.9), RCV (%) 106.7 (96.6-120.1)/-51.6 (-54.6 to -49.1) and II 0.42 (0.29-0.56). There was a trend for women to have lower CVG. The calculated RCVs were comparable between genders. CONCLUSIONS: cMyC exhibits acceptable RCV and low II suggesting that it could be suitable for disease monitoring, risk stratification and prognostication if measured serially. Analytical quality specifications based on biological variation are similar to those for cardiac troponin and should be achievable at clinically relevant concentrations.

Biological variation of secretoneurin; a novel cardiovascular biomarker implicated in arrhythmogenesis.

BACKGROUND: Secretoneurin is a novel prognostic biomarker that may predict mortality in heart failure and the occurrence of ventricular arrhythmias. This study reports the within subject variation (CVI), between subject variation (CVG), reference change values (RCV) and index of individuality (II) of secretoneurin. METHODS: Thirty healthy volunteers were included. Non-fasting samples were obtained between 8 and 10 am once a week for ten weeks. Secretoneurin was analyzed in duplicate using ELISA. No outliers were present according to Burnett and Reeds' criteria. Simple linear regression did not identify significant trends. Variance homogeneity in the analytical variance and CVI were tested using Cochrane's and Bartlett's tests and four participants were excluded. Calculation of CVI, CVG and RCV were done on ln transformed data as described by Fokkema, the II was calculated using retransformed data. RESULTS: The median age of the participants was 36 years and 53% were female. Non-fasting glucose, eGFR(CKD-EPI), cTnT and NT-proBNP concentrations were within the normal range. Median secretoneurin concentrations were 38 pmol/L (women) and 33 pmol/L (men), p-value < 0.001. CVI and CVG were 9.8% (CI 8.7% to 11.0%) and 20.0 (CI 15.4% to 28.0%), respectively. RCV were 38.7% (CI 35.5% to 42.7%) and -27.9 (CI -29.9 to -26.2) and the II were 0.60 (CI 0.42-0.78). No gender differences were present. CONCLUSION: Secretoneurin has a fairly low CVI, CVG, RCV and II, indicating that it could be suitable as a diagnostic or prognostic biomarker and that delta values in serial samplings may be preferable for identifying clinical changes.

ß-Amyloid in Cerebrospinal Fluid: How to Keep It Floating (Not Sticking) by Standardization of Preanalytic Processes and Collection Tubes.

BACKGROUND: Phosphorylated tau (pTau), total tau (tTau), and ß-amyloid (Aß) are established cerebrospinal fluid (CSF) biomarkers used to help diagnose Alzheimer disease. Preanalytic workups of CSF samples lack harmonization, making interlaboratory comparison of these biomarkers challenging. The Aß adsorbs to sample tubes, yielding underestimated concentrations, and may result in false Alzheimer disease diagnosis. Our primary aim was to compare Aß recovery across multiple polypropylene tubes and to test the stability of tTau, pTau, and Aß in the best performing tube. METHODS: Eight polypropylene tubes were tested using 3 CSF pools with Aß concentrations <500, 500-1000, and >1000 ng/L. All samples were analyzed in duplicate. Tubes were cut open to assess their different infrared adsorption spectra. Freshly drawn CSF from 14 patients was distributed into 4 Sarstedt 5-mL (no. 63.504.027; Sar5CSF) tubes, left at room temperature for up to 7 days, and analyzed for pTau, tTau, and Aß by ELISA. RESULTS: Two Sarstedt 5-mL tubes and a Sarstedt 10-mL (Sar10CSF) tube showed significantly higher Aß recovery at all 3 concentrations compared with the 5 other tubes. The infrared adsorption spectra of Sar10CSF and Sar5CSF tubes were practically identical, unlike the other tubes. No significant loss of pTau, tTau, and Aß was observed in CSF left at room temperature for up to 7 days (P > 0.05). CONCLUSIONS: Recovery of Aß from Sar5CSF tubes is equivalent to Aß recovery from Sar10CSF tubes. Levels of pTau, tTau, and Aß were stable for at least 7 days at room temperature but not at 37 °C.

High-sensitivity cardiac troponin T and N-terminal pro-B-type natriuretic peptide in acute heart failure: Data from the ACE 2 study.

BACKGROUND: To assess if cardiac troponins can improve diagnostics of acute heart failure (AHF) and provide prognostic information in patients with acute dyspnea. METHODS: We measured cardiac troponin T with a high-sensitivity assay (hs-cTnT) in 314 patients hospitalized with acute dyspnea. The index diagnosis was adjudicated and AHF patients were stratified into AHF with reduced or preserved ejection fraction (HFrEF/HFpEF). The prognostic and diagnostic merit of hs-cTnT was compared to the merit of N-terminal pro-B-type natriuretic peptide (NT-proBNP). RESULTS: In the total population, median age was 73 (quartile [Q] 1-3 63-81) years and 48% were women. One-hundred-forty-three patients were categorized as AHF (46%) and these patients had higher hs-cTnT concentrations than patients with non-AHF-related dyspnea: median 38 (Q1-3 22-75) vs. 13 (4-25) ng/L; p < 0.001. hs-cTnT concentrations were similar between patients with HFrEF and HFpEF (p = 0.80), in contrast to NT-proBNP, which was higher in HFrEF (p < 0.001). C-statistics for discriminating HFpEF from non-AHF-related dyspnea was 0.80 (95% CI 0.73-0.86) for hs-cTnT, 0.79 (0.73-0.86) for NT-proBNP, and 0.83 (0.76-0.89) for hs-cTnT and NT-proBNP in combination. Elevated hs-cTnT remained associated with HFpEF in logistic regression analysis after adjusting for demographics, comorbidities and renal function. During median 27 months of follow-up, 114 (36%) patients died in the total population. Higher hs-cTnT concentrations were associated with increased risk of all-cause mortality after adjustment for clinical variables and NT-proBNP: hazard ratio 1.30 (95% CI 1.07-1.58), p = 0.009. CONCLUSION: hs-cTnT measurements improve diagnostic accuracy for HFpEF and provide independent prognostic information in unselected patients with acute dyspnea.

Growth Differentiation Factor 15 Provides Prognostic Information Superior to Established Cardiovascular and Inflammatory Biomarkers in Unselected Patients Hospitalized With COVID-19.

BACKGROUND: Growth differentiation factor 15 (GDF-15) is a strong prognostic marker in sepsis and cardiovascular disease (CVD). The prognostic value of GDF-15 in coronavirus disease 2019 (COVID-19) is unknown. METHODS: Consecutive, hospitalized patients with laboratory-confirmed infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and symptoms of COVID-19 were enrolled in the prospective, observational COVID Mechanisms Study. Biobank samples were collected at baseline, day 3 and day 9. The primary end point was admission to the intensive care unit or death during hospitalization, and the prognostic performance of baseline and serial GDF-15 concentrations were compared with that of established infectious disease and cardiovascular biomarkers. RESULTS: Of the 123 patients enrolled, 35 (28%) reached the primary end point; these patients were older, more often had diabetes, and had lower oxygen saturations and higher National Early Warning Scores on baseline. Baseline GDF-15 concentrations were elevated (>95th percentile in age-stratified healthy individuals) in 97 (79%), and higher concentrations were associated with detectable SARS-CoV-2 viremia and hypoxemia (both P<0.001). Patients reaching the primary end point had higher concentrations of GDF-15 (median, 4225 [IQR, 3197-5972] pg/mL versus median, 2187 [IQR, 1344-3620] pg/mL, P<0.001). The area under the receiver operating curve was 0.78 (95% CI, 0.70-0.86). The association between GDF-15 and the primary end point persisted after adjusting for age, sex, race, body mass index, estimated glomerular filtration rate, previous myocardial infarction, heart failure, and atrial fibrillation (P<0.001) and was superior and incremental to interleukin-6, C-reactive protein, procalcitonin, ferritin, D-dimer, cardiac troponin T, and N-terminal pro-B-type natriuretic peptide. Increase in GDF-15 from baseline to day 3 was also greater in patients reaching the primary end point (median, 1208 [IQR, 0-4305] pg/mL versus median, -86 [IQR, -322 to 491] pg/mL, P<0.001). CONCLUSIONS: GDF-15 is elevated in the majority of patients hospitalized with COVID-19, and higher concentrations are associated with SARS-CoV-2 viremia, hypoxemia, and worse outcome. The prognostic value of GDF-15 was additional and superior to established cardiovascular and inflammatory biomarkers. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04314232.

N-terminal pro-B-type natriuretic peptide as a prognostic indicator for 30-day mortality following out-of-hospital cardiac arrest: a prospective observational study.

BACKGROUND: Early risk stratification applying cardiac biomarkers may prove useful in sudden cardiac arrest patients. We investigated the prognostic utility of early-on levels of high sensitivity cardiac troponin-T (hs-cTnT), copeptin and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with out-of-hospital cardiac arrest (OHCA). METHODS: We conducted a prospective observational unicenter study, including patients with OHCA of assumed cardiac origin from the southwestern part of Norway from 2007 until 2010. Blood samples for later measurements were drawn during cardiopulmonary resuscitation or at hospital admission. RESULTS: A total of 114 patients were included, 37 patients with asystole and 77 patients with VF as first recorded heart rhythm. Forty-four patients (38.6%) survived 30-day follow-up. Neither hs-cTnT (p = 0.49), nor copeptin (p = 0.39) differed between non-survivors and survivors, whereas NT-proBNP was higher in non-survivors (p <  0.001) and significantly associated with 30-days all-cause mortality in univariate analysis, with a hazard ratio (HR) for patients in the highest compared to the lowest quartile of 4.6 (95% confidence interval (CI), 2.1-10.1), p <  0.001. This association was no longer significant in multivariable analysis applying continuous values, [HR 0.96, (95% CI, 0.64-1.43), p = 0.84]. Similar results were obtained by dividing the population by survival at hospital admission, excluding non-return of spontaneous circulation (ROSC) patients on scene [HR 0.93 (95% CI, 0.50-1.73), P = 0.83]. We also noted that NT-proBNP was significantly higher in asystole- as compared to VF-patients, p <  0.001. CONCLUSIONS: Early-on levels of hs-cTnT, copeptin and NT-proBNP did not provide independent prognostic information following OHCA. Prediction was unaffected by excluding on-scene non-ROSC patients in the multivariable analysis. TRIAL REGISTRATION: ClinicalTrials. gov, NCT02886273 .

Diagnostic and prognostic properties of procalcitonin in patients with acute dyspnea: Data from the ACE 2 Study.

BACKGROUND: Procalcitonin (PCT) concentrations increase during bacterial infections and could improve diagnosis of pneumonia and risk stratification in patients with acute dyspnea. METHODS: PCT concentrations were measured <24 h of admission in 310 patients with acute dyspnea and compared to C-reactive protein (CRP) and white blood cells (WBC) in the total cohort and the subset of patients with concomitant acute heart failure (HF). RESULTS: We diagnosed pneumonia in 16 out of 140 patients with acute HF (11%) and in 45 out of 170 patients with non-HF-related dyspnea (27%). PCT concentrations were higher in patients with pneumonia vs. patients without pneumonia, both among acute HF patients (median 2.79 [Q1-3 0.18-5.80] vs. 0.10 [0.07-0.14] ng/mL, p < .001) and non-HF patients (0.22 [Q1-3 0.13-0.77] vs. 0.07 [0.05-0.10] ng/mL, p < .001). CRP and WBC were also higher in patients with pneumonia in both groups, but among acute HF patients, only PCT concentrations were associated with pneumonia in multivariate analysis. In patients with acute HF, receiver-operating statistics area under the curve (ROC-AUC) to diagnose pneumonia was 0.90 (95% CI 0.81-0.98) for PCT, 0.84 (0.73-0.94) for CRP, and 0.72 (0.57-0.87) for WBC. The corresponding ROC-AUCs among patients with non-HF-related dyspnea were 0.88 (0.82-0.93), 0.94 (0.90-0.98), and 0.79 (0.72-0.87), respectively. During a median follow-up of 823 days (Q1-3 471-998) 114 patients died, and PCT and CRP, but not WBC concentrations were associated with all-cause mortality. CONCLUSION: In acute HF patients, PCT concentrations were superior to CRP and WBC to diagnose concurrent pneumonia.

Initial Phase NT-proBNP, but Not Copeptin and High-Sensitivity Cardiac Troponin-T Yielded Diagnostic and Prognostic Information in Addition to Clinical Assessment of Out-of-Hospital Cardiac Arrest Patients With Documented Ventricular Fibrillation.

AIM: Sudden cardiac arrest (SCA) secondary to ventricular fibrillation (VF) may be due to different cardiac conditions. We investigated whether copeptin, hs-cTnT and NT-proBNP in addition to clinical assessment may help to identify the etiology of SCA and yield prognostic information. METHODS AND RESULTS: EDTA-blood was collected prior to or at hospital admission from patients with SCA of assumed cardiac origin. Clinical data were obtained from hospital records. VF was the primary heart rhythm in 77 patients who initially were divided into 2 groups based on whether they had an ischemic or non-ischemic mechanism as the most likely cause of SCA. They were further divided into 4 groups according to whether or not they had a history of previous heart disease. The patients were categorized by baseline clinical information, ECG, echocardiography and coronary angiography; Group 1 (n = 43): SCA with first AMI, Group 2 (n = 10): SCA with AMI and previous MI, Group 3 (n = 3): SCA without AMI and without former heart disease, Group 4 (n = 18): SCA without AMI and with known heart disease. Copeptin and hs-cTNT did not differ between patient groups, whereas NT-proBNP was significantly higher in patients with established heart disease without AMI and differed between non-AMI and AMI. Furthermore, NT-proBNP was significantly elevated in non-survivors as compared to survivors. CONCLUSION: NT-proBNP provided both diagnostic and prognostic information in blood samples collected close to out-of-hospital resuscitation of VF patients, whereas copeptin and hs-cTnT failed to do so. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02886273.

Prognostic and diagnostic significance of mid-regional pro-atrial natriuretic peptide in acute exacerbation of chronic obstructive pulmonary disease and acute heart failure: data from the ACE 2 Study.

PURPOSE: To compare the diagnostic and prognostic value of mid-regional pro-ANP (MR-proANP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with acute dyspnea. METHODS: MR-proANP and NT-proBNP were measured with commercial immunoassays at hospital admission (n = 313), on day 2 (n = 234), and before discharge (n = 91) and compared for diagnosing acute heart failure (HF; n = 143) and to predict mortality among patients with acute HF and acute exacerbation of chronic obstructive pulmonary disease (AECOPD; n = 84) separately. RESULTS: The correlation coefficient between MR-proANP and NT-proBNP was 0.89 (p < 0.001) and the receiver-operating area under the curve (AUC) was 0.85 (95% CI 0.81-0.89) for MR-proANP and 0.86 (0.82-0.90) for NT-proBNP to diagnose acute HF. During a median follow-up of 816 days, mortality rates were 46% in acute HF patients and 42% in AECOPD patients. After adjustment for other risk variables by multivariate Cox regression analysis, MR-proANP and NT-proBNP concentrations were associated with mortality in patients with acute HF, but only MR-proANP were associated with mortality among patients with AECOPD: hazard ratio (lnMR-proANP) 1.98 (95% CI 1.17-3.34). CONCLUSION: MR-proANP and NT-proBNP concentrations provide similar diagnostic and prognostic information in patients with acute HF. In contrast to NT-proBNP, MR-proANP measurements also provided independent prognostic information in AECOPD patients.

The copeptin response after physical activity is not associated with cardiac biomarkers or asymptomatic coronary artery disease: The North Sea Race Endurance Exercise Study (NEEDED) 2013.

BACKGROUND: Copeptin concentrations increase both during acute coronary syndrome and following physical exercise. The relationship between copeptin increase following physical exercise and coronary artery disease (CAD) is uncertain. The aim of this study was to 1) describe the copeptin response following strenuous physical exercise, and 2) investigate the determinants of exercise induced copeptin concentrations, particularly in relation to cardiac biomarkers and CAD. METHODS: Serum samples were collected from 97 recreational cyclists 24h before, and immediately, 3 and 24h after a 91-km bike race. Three subjects were subsequently diagnosed with significant asymptomatic CAD. Delta copeptin concentrations were correlated to patient characteristics and to biomarker concentrations. RESULTS: Participants were 42.8±9.6years, and 76.3% were male. Copeptin concentrations increased to maximal levels immediately after the race and were normalized in >90% after 3h. A total of 53% and 39% exceeded the 95th and 99th percentile of the assay (10 and 19pmol/L) respectively. In multivariate models, race time, serum sodium, creatinine and cortisol were significant predictors of copeptin levels. There was no correlation between changes in copeptin and changes in cardiac biomarkers (hs-cTnI, hs-cTnT and BNP). Copeptin concentrations were normal in the subjects with asymptomatic CAD. CONCLUSIONS: The moderate, short-term, exercise induced copeptin increase observed in the present study was not related to hs-cTn or BNP levels. Copeptin was normal in three asymptomatic recreational athletes with significant CAD.

Prognostic and diagnostic significance of copeptin in acute exacerbation of chronic obstructive pulmonary disease and acute heart failure: data from the ACE 2 study.

BACKGROUND: Copeptin is a novel biomarker that predicts mortality in lower respiratory tract infections and heart failure (HF), but the diagnostic value of copeptin in acute dyspnea and the prognostic significance of copeptin in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is not clear. METHOD: We determined copeptin and NT-proBNP concentrations at hospital admission in 314 patients with acute dyspnea who were categorized by diagnosis. Survival was registered after a median follow-up of 816 days, and the prognostic and diagnostic properties of copeptin and NT-proBNP were analyzed in acute HF (n = 143) and AECOPD (n = 84) separately. RESULTS: The median concentration of copeptin at admission was lower in AECOPD compared to acute HF (8.8 [5.2-19.7] vs. 22.2 [10.2-47.9]) pmol/L, p < 0.001), but NT-proBNP discriminated acute HF from non-HF related dyspnea more accurately than copeptin (ROC-AUC 0.85 [0.81-0.89] vs. 0.71 [0.66-0.77], p < 0.0001). Adjusted for basic risk factors, increased copeptin concentrations predicted mortality in AECOPD (HR per log (ln) unit 1.72 [95% CI 1.21-2.45], p = 0.003) and acute HF (1.61 [1.25-2.09], p < 0.001), whereas NT-proBNP concentrations predicted mortality only in acute HF (1.62 [1.27-2.06], p < 0.001). On top of a basic model copeptin reclassified a significant proportion of patients into a more accurate risk strata in AECOPD (NRI 0.60 [0.19-1.02], p = 0.004) and acute HF (0.39 [0.06-0.71], p = 0.020). CONCLUSION: Copeptin is a strong prognostic marker in both AECOPD and acute HF, while NT-proBNP concentrations predict mortality only in patients with acute HF. NT-proBNP levels are superior to copeptin levels to diagnose acute HF in patients with acute dyspnea.

The microINR portable coagulometer: analytical quality and user-friendliness of a PT (INR) point-of-care instrument.

Regular measurement of prothrombin time as an international normalized ratio PT (INR) is mandatory for optimal and safe use of warfarin. Scandinavian evaluation of laboratory equipment for primary health care (SKUP) evaluated the microINR portable coagulometer (microINR®) (iLine Microsystems S.L., Spain) for measurement of PT (INR). Analytical quality and user-friendliness were evaluated under optimal conditions at an accredited hospital laboratory and at two primary health care centres (PHCCs). Patients were recruited at the outpatient clinic of the Laboratory of Medical Biochemistry, St Olav's University Hospital, Trondheim, Norway (n = 98) and from two PHCCs (n = 88). Venous blood samples were analyzed under optimal conditions on the STA-R®Evolution with STA-SPA + reagent (Stago, France) (Owren method), and the results were compared to capillary measurements on the microINR®. The imprecision of the microINR® was 6% (90% CI: 5.3-7.0%) and 6.3% (90% CI: 5.1-8.3) in the outpatient clinic and PHCC2, respectively for INR ≥2.5. The microINR® did not meet the SKUP quality requirement for imprecision ≤5.0%. For INR <2.5 at PHCC2 and at both levels in PHCC1, CV% was ≤5.0. The accuracy fulfilled the SKUP quality goal in both outpatient clinic and PHCCs. User-friendliness of the operation manual was rated as intermediate, defined by SKUP as neutral ratings assessed as neither good nor bad. Operation facilities was rated unsatisfactory, and time factors satisfactory. In conclusion, quality requirements for imprecision were not met. The SKUP criteria for accuracy was fulfilled both at the hospital and at the PHCCs. The user-friendliness was rated intermediate.