Evaluating the performance of an updated high-sensitivity troponin T assay with increased tolerance to biotin.

Objectives: Biotin >20 ng/mL may interfere with the Elecsys Troponin T-high sensitive assay (cTnT-hs; Roche Diagnostics International Ltd). We evaluated the performance of an updated assay, cTnT-hs*, which was designed to reduce biotin interference.

Methods: cTnT-hs* assay performance was assessed using up to two applications (18 min/9 min) on three analyzers (cobas e 411/cobas e 601/cobas e 801).

Analytical and Clinical Validation of a Point-of-Care Cardiac Troponin T Test with an Improved Detection Limit.

Background: The point-of-care test Roche CARDIAC POC Troponin T (PoC TnT) is an improved assay which has been developed for the Roche cobas h 232 system.

Methods: We performed a multicentre evaluation (four sites) to assess the analytical performance of the PoC TnT assay and to compare it with the central laboratory Elecsys® troponin T high sensitive (lab cTnT-hs) assay.

Results: The relative mean differences found in method comparisons of PoC TnT vs.

Equal performance of novel N-terminal proBNP (Cardiac proBNP®) and established BNP (Triage BNP®) point-of-care tests.

Background: Recently, a novel point-of-care test (POCT) for N-terminal proBNP (NTproBNP) has been introduced (Cardiac proBNP®, Roche).

Aim: The aim was to compare the novel POCT for NTproBNP with the established POCT for BNP.

Methods: NTproBNP and BNP were assessed in 222 individuals with chronic heart failure (n = 151) or controls (n = 71) with both POCTs.

Multicentre evaluation of a second generation point-of-care assay with an extended range for the determination of N-terminal pro-brain natriuretic peptide.

Background: In the second generation of the point-of-care (POC) assay Roche CARDIAC proBNP, the upper limit of the measuring range was extended from 3000 to 9000 ng/L.

Methods: A thirteen-site multicentre evaluation was carried out to assess the analytical performance of the POC NT-proBNP assay and to compare it with a laboratory N-terminal pro-brain natriuretic peptide (NT-proBNP) assay.

Results: In method comparisons of six lots of POC NT-proBNP with the lab reference method (Elecsys proBNP) mean bias ranged from -10 to +17%.

Multicentre analytical evaluation of a new point-of-care system for the determination of cardiac and thromboembolic markers.

Background: The cobas h 232 point-of-care analyzer by Roche is the instrument successor of the Cardiac reader allowing the quantitative determination of troponin T, creatine kinase MB, myoglobin, NT-proBNP and D-dimer.

Methods: In this study 1329 patients with acute coronary syndromes, heart failure, thromboembolic or other diseases and 945 healthy donors were assessed. Comparisons versus central laboratory methods were carried out with 2379 samples from these individuals; out of these, 1591 samples gave quantitative results within the measuring range and were included in the evaluation.

Potential of mid-infrared spectroscopy to aid the triage of patients with acute chest pain.

A total of 1,429 serum samples from 389 consecutive patients with acute chest pain were analyzed with the goal to aid the rapid diagnosis of acute myocardial infarction. To the best of our knowledge this is the largest and most comprehensive study on mid-infrared spectroscopy in cardiology. We were able to identify those signatures in the mid-infrared spectra of the samples, which were specific to either acute myocardial infarction or chest pain of other origin (angina pectoris, oesophagitis, etc).

Multicentre evaluation of a new point-of-care test for the determination of CK-MB in whole blood.

Background: The point-of-care (POC) test Roche CARDIAC CK-MB is a new assay which has been developed for the existing Roche Cardiac reader system.

Methods: We performed a multicentre evaluation at six sites to assess the analytical performance of the POC CK-MB assay and to compare it with a quantitative laboratory CK-MB assay.

Results: Within-series coefficients of variation (CV) resulting from 34 ten-fold measurements with patient samples ranged from 4.

Development and calibration of a new point-of-care test for the determination of NT-proBNP in whole blood.

A new point-of-care test for the determination of NT-proBNP in whole blood was developed based on the existing gold-label rapid immunoassay technology of the Roche Cardiac reader system. The novel gold-labelled monoclonal antibody recognizes NT-proBNP at amino acid sequence 27 to 31, the biotinylated polyclonal antibody recognizes sequence 39 to 50. In a model assay based upon the reference method Elecsys proBNP and with an R & D lot of the point-of-care test, this newly selected and developed combination of antibodies showed a very good correlation with the standard Elecsys proBNP assay with correlations of 0.

Multicentre evaluation of a new point-of-care test for the determination of NT-proBNP in whole blood.

Background: The Roche CARDIAC proBNP point-of-care (POC) test is the first test intended for the quantitative determination of N-terminal pro-brain natriuretic peptide (NT-proBNP) in whole blood as an aid in the diagnosis of suspected congestive heart failure, in the monitoring of patients with compensated left-ventricular dysfunction and in the risk stratification of patients with acute coronary syndromes.

Methods: A multicentre evaluation was carried out to assess the analytical performance of the POC NT-proBNP test at seven different sites.

Results: The majority of all coefficients of variation (CVs) obtained for within-series imprecision using native blood samples was below 10% for both 52 samples measured ten times and for 674 samples measured in duplicate.

Sensitivity and specificity of a quantitative point of care D-dimer assay using heparinized whole blood, in patients with clinically suspected deep vein thrombosis.

D-dimer assays are efficient in the exclusion diagnostics of deep vein thrombosis (DVT) in patients without severe concomitant diseases. We have determined diagnostic sensitivity and specificity of a new point-of-care rapid assay for quantitative determination of D-dimer in heparinized whole blood in outpatients with suspected DVT. In 19 participating centers, 637 patients were included in the study, of which 77 were excluded, the majority because of inadequate documentation of analytical quality control measures.

Risk stratification of chest pain patients by point-of-care cardiac troponin T and myoglobin measured in the emergency department.

A prospective multicenter study including 1410 chest pain patients with suspected acute coronary syndromes was carried out to examine the predictive value of biological cardiac markers for adverse events measured by a point-of-care system. Admission cardiac troponin T (cTnT) and myoglobin were measured in parallel on a point-of-care system in the emergency department and -- together with CK-MB mass -- on lab analyzers. In a one-year follow-up, cardiac and non-cardiac death, acute myocardial infarction, unstable angina pectoris and need for revascularization were registered.

Detection limit, cut-off and specificity of an improved rapid assay for cardiac troponin T.

The performance of an improved version of the troponin T rapid test TROPT Sensitive was investigated in a multicentre evaluation at twelve centres. The detection limit and the cut-off were determined in a method comparison with Elecsys Troponin T using a total of 365 samples from patients with suspected acute coronary syndromes and 91 samples from healthy blood donors or non-cardiological patients. The analytical specificity was determined by measuring 1271 blood samples from blood donors without any myocardial injury.

Multicentre evaluation of a new point-of-care test for the quantitative determination of D-dimer.

Imprecision studies, interference testing and multicentre method comparisons using patient samples were carried out with of a new point-of-care test for D-dimer (CARDIAC D-Dimer). The CV of the within-series and the day-to-day imprecision with blood samples and control materials were between 7% and 13%. Compared with Tina-quant D-Dimer, CARDIAC D-Dimer showed a good correlation and accuracy (n=353; r=0.

Recalibration of the point-of-care test for CARDIAC T Quantitative with Elecsys Troponin T 3rd generation.

The rapid troponin T assay CARDIAC T Quantitative was recalibrated using Elecsys Troponin T 3rd Generation as a new reference method. This paper presents the method comparisons at six centres using the new reference method. Method comparison between CARDIAC T Quantitative versus Elecsys Troponin T 3rd Generation were performed using 319 samples from patients with acute coronary syndromes.

Analytical performance of a portable critical care blood gas analyzer.

The portable blood gas analyzer OPTI Critical Care Analyzer was evaluated in comparison to routine laboratory assays using heparinized blood samples of adults and newborns. Within-run imprecision studies were performed with native blood using tonometry to adjust blood gas concentrations. The results obtained show a very close agreement between the OPTI system and the comparison methods for all parameters tested: hemoglobin (y=1.

Time-dependent diagnostic performance of a rapid troponin T version 2 bedside test in patients with acute coronary syndromes.

In a prospective trial, the diagnostic performance of the second version of the troponin T rapid assay (Trop T; cutoff 0.2 microg/L) was compared with the quantitative cardiac-specific troponin T assay (cTnT ELISA; cutoff 0.1 microg/L) and other established cardiac markers such as CK, CK-MB activity, CK-MB mass and myoglobin.

Evaluation of a point-of-care system for quantitative determination of troponin T and myoglobin.

We present the results of a multicenter evaluation of a new point-of-care system (Cardiac Reader) for the quantitative determination of cardiac troponin T (CARDIAC T Quantitative test) and myoglobin (CARDIAC M test) in whole blood samples. The Cardiac Reader is a CCD camera that optically reads the immunochemical test strips. The measuring range is 0.

Long-term prognostic value of serial troponin T bedside tests in patients with acute coronary syndromes.

The early presence of troponin T in serum strongly predicts short-term mortality and myocardial infarction in patients with acute coronary syndromes. We investigated the long-term outcome of the prognostic significance of the troponin T rapid bedside assay (TROPT) and compared this with the quantitative troponin T assay (cTnT enzyme-linked immunosorbent assay), myoglobin and creatine kinase-MB (CK-MB) mass. One hundred sixty-three patients with chest pain and suspected acute coronary syndromes were studied and followed prospectively for 3 years.

Analytical and clinical performance of an improved qualitative troponin T rapid test in laboratories and critical care units.

Objective: To evaluate the performance of a visual troponin T rapid test in the hands of nontraditionally trained personnel of 2 critical care units in comparison to 3 laboratories.

Methods: Method comparisons of the troponin T rapid test versus cardiac troponin T enzyme-linked immunosorbent assay were performed with 804 samples from 510 patients with suspected acute coronary syndromes. Cross-reactivity with skeletal troponin T was studied up to 5000 microg/L.

Quantitative bedside assay for cardiac troponin T: a complementary method to centralized laboratory testing.

Background: In the evaluation of chest pain patients, whole blood bedside assays of highly specific cardiac molecules may be an attractive alternative to centralized clinical chemistry testing. We now report on an optimized test strip device for cardiac troponin T (cTnT) that can be analyzed by a cardiac reader for quantitative assessment of the test result.

Methods And Results: The cTnT test strip reader measures, via a CCD camera, the reflectance of the signal line.

[Patient self-monitoring in follow-up of long-term anticoagulant therapy].

The CoaguChek system is a new system for simple self-testing of prothrombin time from capillary blood. The instrument works with a measuring principle which is completely new in coagulation: the motion of magnetic micro-particles in an oscillating magnetic field is stopped by the fibrin clot and is detected by a photodetector. The existing data show the analytical and clinical reliability of the system.

An improved rapid troponin T test with a decreased detection limit: a multicentre study of the analytical and clinical performance in suspected myocardial damage.

In a multicentre study, we evaluated the analytical and diagnostic performance of the second version of the TROPT rapid test (TROPT 2, CARDIACT in the US). We tested TROPT 2 on 796 blood samples from 487 patients admitted on suspicion of myocardial infarction between 1 and 72 h after onset of symptoms and determined cTnT ELISA and CK MB mass in the corresponding serum samples. Frequency distributions of the results with TROPT 2 showed a detection limit of 0.

Multicentre evaluation of an immunological rapid test for the detection of troponin T in whole blood samples.

In a multicentre study we assessed the analytical and diagnostic performance of a rapid test (TROPT rapid test, Boehringer Mannheim; in the USA: CARDIACT) for cardiac troponin T compared to quantitative troponin T ELISA and creatine kinase-MB mass determinations. The rapid test requires 150 microliters of heparinized or EDTA whole blood; serum is not suitable. Interference testing with biotin, haemoglobin and 27 standard drugs yielded no significant influence in the physiological range.

Multicenter evaluation of a new capillary blood prothrombin time monitoring system.

The analytical performance of the new capillary blood prothrombin time monitoring system CoaguChek was examined in a multicenter evaluation at six hospitals. The coefficients of variation of the INR obtained in the CoaguChek imprecision study were approximately 7% in the control plasma provided (within-run and day-to-day) and 4% in blood (within-run). The prothrombin times were ascertained in capillary blood (CoaguChek PT Test) and citrated venous plasma (Hepato Quick, Thromborel S) from 359 patients under oral anticoagulation therapy with phenprocoumon, acenocoumarin or warfarin.