Clinical biochemistry
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Clinical biochemistry · Mar 2015
ReviewIFCC educational materials on selected analytical and clinical applications of high sensitivity cardiac troponin assays.
In 2011, the IFCC Task Force on Clinical Applications of Cardiac Bio-Markers (TF-CB) was formed, with the purpose of providing evidence based educational materials to assist all biomarker users, i.e. laboratorians, clinicians, researchers, in-vitro diagnostics and regulatory agencies, in better understanding important analytical and clinical aspects of established and novel cardiac biomarkers for use in clinical practice and research. The goal of the task force was to promulgate the same information conjointly through the in vitro diagnostic industry to the laboratory, emergency department and cardiologists. The initial undertaking of the TF-CB, which is comprised of laboratory medicine scientists, emergency medicine physicians and cardiologists, was to address two key issues pertaining to implementing high-sensitivity cardiac troponin (hs-cTn) assays in clinical practice: the 99th percentile upper reference limit (URL) and calculating serial change values in accord with the Universal Definition of AMI. The highlights of both concepts from IFCC statements are described.
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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.
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Clinical biochemistry · Mar 2015
An approach to rule-out an acute cardiovascular event or death in emergency department patients using outcome-based cutoffs for high-sensitivity cardiac troponin assays and glucose.
The application of "undetectable" high-sensitivity cardiac troponin (hs-cTn) concentrations to "rule-out" myocardial infarction is appealing, but there are analytical concerns and a lack of consensus on what concentration should be used to define the lower reportable limit; i.e., limit of detection (LoD) or limit of blank. An alternative approach is to utilize a measurable hs-cTn concentration that identifies patients at low-risk for a future cardiovascular event combined with another prognostic test, such as glucose. We assessed both of these approaches in different emergency department (ED) cohorts to rule-out an event. ⋯ The combination of a "healthy" hs-cTn concentration with glucose might effectively rule-out patients for an acute cardiovascular event at ED presentation.
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Clinical biochemistry · Mar 2015
Observational StudyDecreasing troponin turnaround time in the emergency department using the central laboratory: A process improvement study.
To implement collaborative process improvement measures to reduce emergency department (ED) troponin turnaround time (TAT) to less than 60min using central laboratory. ⋯ After process improvement and implementation of the new workflow model, decreased median TAT (in min) was seen in door-to-order (54 [IQR43] vs. 11 [IQR20]), order-to-collect (15 [IQR 23] vs. 10 [IQR12]), collect-to-received (6 [IQR8] vs. 5 [IQR5]), received-to-result (30 [IQR12] vs. 24 [IQR11]), and overall door-to-result (117 [IQR60] vs. 60 [IQR40]). A troponin TAT of <60min was realized beginning in May 2012 (59 [IQR39]). Hemolysis rates decreased (14.63±0.74 vs. 3.36±1.99, p<0.0001), as did ED length of stay (5.87±2.73h vs. 5.15±2.34h, p<0.0001). Conclusion Troponin TAT of <60min using a central laboratory was achieved with collaboration between the ED and the laboratory; additional findings include a decreased ED length of stay.