Clinical biochemistry
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Clinical biochemistry · Jan 2019
Multicenter StudyA novel Sigma metric encompasses global multi-site performance of 18 assays on the Abbott Alinity system.
The Abbott Alinity family of chemistry and immunoassay systems recently launched with early adopters contributing imprecision and bias data, which was consolidated to assess the performance of Alinity assays across multiple sites using the Sigma metric. Multi-site Sigma metrics were determined for 3 ion-selective electrodes, 12 photometric assays, and 3 immunoassays across 11 independent laboratory sites in 9 countries. ⋯ This multi-center study applies a novel application of Sigma metrics to the first Alinity users and reveals analytical performance of greater than 4 Sigma for vast majority of assays. Laboratories with limited resources can leverage larger data sets for Pooled Sigma metric analysis, providing a tool to assess the consistency of analytical performance from multiple sites.
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Clinical biochemistry · Mar 2018
Multicenter Study Clinical Trial Observational StudyThe predictive value of NT-proBNP and hs-TnT for risk of death in cardiac surgical patients.
European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) is used for risk stratification before cardiac surgery, but whether N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (hs-TnT) may add prognostic information to EuroSCORE II is not known. ⋯ Sixty-one patients (9.5%) died during follow-up in cohort #1. Preoperative NT-proBNP and hs-TnT concentrations correlated (rho=0.58; p<0.001) and were higher in non-survivors compared to survivors: median 2027 (Q1-3 478-5387) vs. 373 (134-1354) ng/L [NT-proBNP] and 39 (16-191) vs. 13 (8-32) ng/L [hs-TnT]; p<0.001 for both. Preoperative NT-proBNP concentrations were associated with time to death after adjustment for EuroSCORE II (HR [lnNT-proBNP] 1.33 [95% CI 1.08-1.64]), p=0.008 and reclassified patients on top of EuroSCORE II (net reclassification index 0.39 [95% CI 0.14-0.64], p=0.003). Pre- and postoperative NT-proBNP concentrations were closely correlated (rho=0.80, p<0.001) and postoperative NT-proBNP concentrations were also associated with long-term mortality after adjustment for EuroSCORE II. A parsimonious risk model that included age, creatinine clearance, chronic pulmonary disease, and NT-proBNP measurements provided comparable prognostic accuracy as EuroSCORE II in cohort #1 and #2 for risk of long-term mortality. hs-TnT measurements did not add to NT-proBNP measurements CONCLUSION: NT-proBNP measurements could improve and simplify risk prediction in cardiac surgical patients.
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Clinical biochemistry · Mar 2015
Multicenter StudyDiagnostic performance of cardiac Troponin I for early rule-in and rule-out of acute myocardial infarction: Results of a prospective multicenter trial.
To compare emergency department TnI serial sampling intervals, determine optimal diagnostic thresholds, and report representative diagnostic performance characteristics for early rule-in and rule-out of MI. ⋯ We report a large multicenter prospective adjudicated trial assessing troponin for early rule-in and rule-out using the Universal Definition of MI and conducted in primary care hospital-associated emergency departments. Our study demonstrates high diagnostic accuracy at early observation times, and reinforces consensus recommendations for sampling on admission and 3h later, repeated at 6h when clinical suspicion remains high.
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Clinical biochemistry · Mar 2015
Multicenter Study Observational StudyCombining presentation high-sensitivity cardiac troponin I and glucose measurements to rule-out an acute myocardial infarction in patients presenting to emergency department with chest pain.
The use of high sensitivity troponin (hs-Tn) may enable early rule out of acute myocardial infarction (AMI) for patients presenting to the emergency department (ED) with chest pain. This study evaluated two approaches to the early rule out of AMI; a combination of a presentation hs-Tn <4ng/L and normal glucose at presentation (dual testing) and a presentation hs-Tn troponin below the limit of detection (LoD). ⋯ The dual testing and LoD approach identified all patients with index AMI and could be used to reduce the proportion of patients requiring lengthy assessment and inpatient admission. Further investigation is still required to rule out unstable angina pectoris in patients identified as low risk.
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Clinical biochemistry · Mar 2015
Multicenter StudyAbsolute and relative changes (delta) in troponin I for early diagnosis of myocardial infarction: Results of a prospective multicenter trial.
We investigated absolute and relative cardiac troponin I (TnI) delta changes, optimal sampling protocols, and decision thresholds for early diagnosis of myocardial infarction (MI). Serial cardiac biomarker values demonstrating a rise and/or fall define MI diagnosis; however the magnitude of change, timing, and diagnostic accuracy of absolute versus relative (percentage) deltas remains unsettled. ⋯ Absolute delta performed significantly better than relative delta at all time intervals. Baseline TnI and absolute delta may be used in conjunction to estimate probability of MI. Consensus recommendations are supported for sampling on admission and 3h later, repeated at 6h in patients when clinical suspicion remains high.