Cardiac troponin changes to distinguish type 1 and type 2 myocardial infarction and 180-day mortality risk.

Aims: To determine the ability of serial cardiac troponin (cTnI) changes (delta) to distinguish type 1 and type 2 myocardial infarction (MI) (excluding all ST-segment elevation MIs (STEMIs)) and describe the diagnostic accuracy and 180-day mortality in MI versus no-MI patients.

Methods And Results: Serial cTnIs were measured in 1112 consecutive patients without STEMI and within 6h of presentation to a United States emergency department: 856 (77%) with no MI, 66 (6%) type 1 MI, and 190 (17%) type 2 MI. Of the 0 to 3h and 0 to 6h absolute and relative cTnI changes, only the distribution of absolute change from 0 to 6h was significantly different between type 1 and type 2 MI: median (interquartile range) 311 (1430) ng/l vs.

Diagnostic performance of four point of care cardiac troponin I assays to rule in and rule out acute myocardial infarction.

Objective: This study evaluated the diagnostic performance of four point-of-care (POC) cardiac troponin I (cTnI) assays compared to a central laboratory cTnI assay for detecting myocardial injury and diagnosing acute myocardial infarction (AMI).

Design And Methods: Plasma obtained at admission, 3 h, and 6 h post-admission in 169 patients presenting with symptoms suggestive of acute coronary syndrome (ACS) was studied. cTnI concentrations were measured on the Instrumentation Laboratory prototype GEM Immuno, Radiometer AQT90, Mitsubishi PATHFAST, Abbott i-STAT and the Ortho-Clinical Diagnostic Vitros assays.

Performance characteristics of the ARCHITECT Galectin-3 assay.

Objectives: Galectin-3 is an emerging biomarker that is commonly increased in patients with heart failure and/or patients at risk for cardiovascular disease. We evaluated the Galectin-3 assay on the Abbott ARCHITECT i1000(SR) and ARCHITECT i2000(SR) at 2 testing sites.

Design And Methods: Imprecision (%CV), interference, limits of blank (LoB), detection (LoD), and quantitation (LoQ), linearity, method comparison to an ELISA method, comparisons between plasma and serum, and reference intervals were evaluated.

Determination of 19 cardiac troponin I and T assay 99th percentile values from a common presumably healthy population.

Background: Between-assay comparability of 99th percentiles for cardiac troponin concentrations has not been assessed systematically in a single population for a large number of assays.

Methods: We determined 99th percentiles for 19 cardiac troponin assays in heparin plasma samples from a population of 272 and 252 presumably healthy males and females, respectively. The assays evaluated included 1 cardiac troponin T (cTnT) assay from Roche and 18 cTnI assays from Abbott, Alere, Beckman, bioMerieux, Instrumentation Laboratory, Ortho-Clinical Diagnostics, Singulex, Siemens, and Roche.

Delta changes for optimizing clinical specificity and 60-day risk of adverse events in patients presenting with symptoms suggestive of acute coronary syndrome utilizing the ADVIA Centaur TnI-Ultra assay.

Objectives: We determined diagnostic accuracy and risk stratification using delta changes for the cardiac troponin I (cTnI) Centaur Ultra assay for ruling out acute myocardial infarction (AMI) and for risk prediction of adverse events in patients with symptoms of acute coronary syndrome.

Design And Methods: cTnI was measured on admission and 6-24 h in 371 patients. Optimal deltas (percent change, absolute value of percent change, change, absolute value of change) were determined from ROC curve analysis.

Increased cardiac troponin I as measured by a high-sensitivity assay is associated with high odds of cardiovascular death: the Minnesota Heart Survey.

Background: We examined several novel biomarkers of different pathophysiologic pathways as predictors of cardiovascular mortality in participants enrolled in the Minnesota Heart Survey (MHS), a population-based study of cardiovascular disease (CVD) risk factors.

Methods: In a nested case-control study within MHS, 7 biomarkers were assayed in serum samples from 211 patients identified after 8-15 years of follow-up who died of cardiovascular causes (cardiovascular heart disease, stroke, congestive heart failure) and 253 controls matched on age, sex, and study year. Logistic regression analysis, adjusted for age, race, sex, education, study year, smoking, abdominal obesity, diabetes, serum total cholesterol, systolic blood pressure, previous hospitalization for a CVD event, and other significant biomarkers, was used to evaluate the relations of biomarkers relative to the odds of CVD mortality.

Myeloperoxidase improves risk stratification in patients with ischemia and normal cardiac troponin I concentrations.

Background: We assessed the ability of myeloperoxidase (MPO) to identify the risk for major adverse cardiac events (MACE) in patients who present with ischemic symptoms suggestive of acute coronary syndrome and have a normal cardiac troponin I (cTnI) value.

Methods: We used Siemens (n = 400) and Abbott (n = 350) assays to measure MPO and cTnI in plasma samples from 400 patients. Event rates (myocardial infarction, cardiac death, percutaneous coronary intervention, coronary artery bypass grafting) were estimated by the Kaplan-Meier method and compared with the log-rank statistic.

Measurement of B-type natriuretic peptide by two assays utilizing antibodies with different epitope specificity.

Objectives: To compare plasma BNP values determined by a conventional-type and a novel-type of BNP assays.

Design And Methods: Plasma samples (n=94) from HF patients were analyzed by the novel-type "Single Epitope Sandwich" (SES assay prototype) and the conventional-type Siemens ADVIA Centaur BNP assays. Both assays were calibrated using recombinant proBNP (expressed in E.

Defining the serum 99th percentile in a normal reference population measured by a high-sensitivity cardiac troponin I assay.

Objectives: This study determined the serum 99th percentile reference value for cTnI measured using the high sensitivity Erenna cTnI assay.

Design And Methods: Serum was obtained from healthy adults (n=348); aged 18-76 years of which 147 were males and 201 were females. Nonparametric analysis was performed to determine the 99th percentiles.

Role of monitoring changes in sensitive cardiac troponin I assay results for early diagnosis of myocardial infarction and prediction of risk of adverse events.

Background: We sought to determine the diagnostic accuracy of the cardiac troponin I (cTnI) VITROS(R) Troponin I-ES assay for early detection of acute myocardial infarction (AMI) and for risk prediction of adverse events in patients with symptoms of acute coronary syndrome (ACS).

Methods: cTnI was measured on admission and approximately 6 h postadmission in 381 patients. The 99th percentile cTnI concentration (0.

Assessment of the multiple-biomarker approach for diagnosis of myocardial infarction in patients presenting with symptoms suggestive of acute coronary syndrome.

Background: Cardiac troponin is the preferred biomarker for detecting acute myocardial injury and infarction (MI). We studied whether multiple biomarkers of numerous pathophysiological pathways would increase the diagnostic accuracy for detecting MI.

Methods: Seven biomarkers [myeloperoxidase, soluble CD40 ligand, placental growth factor, matrix metalloproteinase 9 (MMP-9), high-sensitivity C-reactive protein (hsCRP), cardiac troponin I (cTnI), N-terminal pro-B-type natriuretic peptide] and estimated glomerular filtration rate were measured in 457 patients presenting on admission with symptoms suggestive of acute coronary syndrome.

Analytical characteristics of commercial cardiac troponin I and T immunoassays in serum from rats, dogs, and monkeys with induced acute myocardial injury.

Background: Information is needed regarding analytical characteristics of cardiac troponin (cTn) assays used in preclinical studies.

Methods: We measured cTnI and cTnT in serum from normal animals and animals with induced myocardial injury [Sprague-Dawley (SD) and Wistar rats, beagle dogs, and rhesus (Rh) and cynomolgus (Cy) monkeys]. We evaluated the following assays: for cTnI, Abbott Architect, Bayer Centaur (first and second generation), Beckman Access, DPC Immulite, Dade Dimension, Ortho Vitros ES, Tosoh AIA, and species-specific enzyme immunoassays; for cTnT, Roche Elecsys.

Novel immunoassay for quantification of brain natriuretic peptide and its precursor in human blood.

Background: Brain natriuretic peptide (BNP) is an unstable molecule that can rapidly lose immunologic activity in blood. Conventional sandwich BNP immunoassays use 2 antibodies specific to 2 different epitopes. Larger distances between epitopes are associated with a greater probability of proteolysis sites being located between the antibody-binding sites, and thus such assays have an increased susceptibility to underdetect BNP because of the increased likelihood of proteolytic degradation.

Immunodetection of glycosylated NT-proBNP circulating in human blood.

Background: Brain natriuretic peptide (BNP) or NT-proBNP (N-terminal fragment of BNP precursor) measurements are recommended as aids in diagnosis and prognosis of patients with heart failure. Recently it has been shown that proBNP is O-glycosylated in human blood. The goal of this study was to map sites on the NT-proBNP molecule that should be recognized by antibodies used in optimal NT-proBNP assays.

Performance characteristics of the Architect brain natriuretic peptide (BNP) assay: a two site study.

Introduction: Brain natriuretic peptide (BNP) is produced by the ventricles of the heart and is a biomarker for heart failure. Several commercial assays are now available. We evaluated the performance characteristics of the ARCHITECT BNP assay.

Use of the Centaur TnI-Ultra assay for detection of myocardial infarction and adverse events in patients presenting with symptoms suggestive of acute coronary syndrome.

Background: We determined the diagnostic accuracy of the Advia Centaur TnI-Ultra assay for detecting myocardial infarction (MI) and assessing risk of adverse events in patients presenting with ischemic symptoms suggestive of acute coronary syndrome.

Methods: We measured cardiac troponin I (cTnI) on admission and 6-24 h after admission (follow-up) in plasma specimens from 371 consecutive patients. The end point was the first of cardiac event or death within 60 days.

Use of the bioMérieux VIDAS troponin I ultra assay for the diagnosis of myocardial infarction and detection of adverse events in patients presenting with symptoms suggestive of acute coronary syndrome.

Background: We demonstrate the performance of the bioMérieux VIDAS Troponin I Ultra assay for diagnostic accuracy for detection of myocardial infarction (MI) and risk stratification.

Method: cTnI was measured in 545 patients from 2 clinical centers with symptoms suggestive of ACS at admission, with an additional specimen at 4-12 h (453 patients). The 99th percentile value (0.

Tumor-induced anorexia and weight loss are mediated by the TGF-beta superfamily cytokine MIC-1.

Anorexia and weight loss are part of the wasting syndrome of late-stage cancer, are a major cause of morbidity and mortality in cancer, and are thought to be cytokine mediated. Macrophage inhibitory cytokine-1 (MIC-1) is produced by many cancers. Examination of sera from individuals with advanced prostate cancer showed a direct relationship between MIC-1 abundance and cancer-associated weight loss.

Analytical and clinical performance of the Ortho-Clinical Diagnostics VITROS amino-terminal pro-B type natriuretic peptide assay.

Background: Measurement of amino-terminal pro-B-type natriuretic peptide (NT-proBNP) is useful for evaluating patients with heart failure (HF).

Methods: We evaluated the performance of a new automated NT-proBNP assay.

Results: The VITROS NT-proBNP assay had mean within-run and total imprecision of 1.

Multi-center validation of the Response Biomedical Corporation RAMP NT-proBNP assay with comparison to the Roche Diagnostics GmbH Elecsys proBNP assay.

Background: NT-proBNP measurements aid in the evaluation of patients with suspected heart failure (HF) and may facilitate risk stratification in patients with HF and acute coronary syndrome (ACS). Point-of-care (POC) assays may provide more timely results and potentially improve patient outcomes.

Methods: We evaluated the analytical performance of the Response Biomedical Corporation whole blood RAMP amino-terminal pro-B type natriuretic peptide (NT-proBNP) POC assay compared to the Roche Elecsys proBNP (NT-proBNP) assay.

Multiple biomarker use for detection of adverse events in patients presenting with symptoms suggestive of acute coronary syndrome.

Background: We investigated multiple biomarkers of various pathophysiologic pathways to determine their relationships with adverse outcomes in patients presenting with symptoms of acute coronary syndrome.

Methods: We obtained plasma specimens from 457 patients on admission and measured 7 biomarkers: myeloperoxidase (MPO), soluble CD40 ligand (CD40L), placental growth factor (PlGF), metalloproteinase-9 (MMP-9), high-sensitivity C-reactive protein (hsCRP), cardiac troponin I (cTnI), and N-terminal pro-B-type natriuretic peptide (NT-proBNP). We used the Modification of Diet in Renal Disease formula to calculate the estimated glomerular filtration rate (eGFR).