Clinical biochemistry
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Clinical biochemistry · Mar 2015
ReviewUse and interpretation of high sensitivity cardiac troponins in patients with chronic kidney disease with and without acute myocardial infarction.
It is well known that the population with chronic kidney disease (CKD) is at greater risk for cardiovascular disease and death than the general population. The use and interpretation of high sensitivity cardiac troponin (hs-cTn) assays have been particularly challenging in these patients with the majority having elevated levels at baseline. The diagnostic accuracy of acute myocardial infarction (AMI) may be decreased in patients with CKD when using these newer troponins. ⋯ The purpose of the review is to evaluate hs-cTn in patients with CKD for the diagnosis of AMI and for the prognostic significance of elevated levels in CKD patients without AMI. Although the underlying etiology of persistently elevated cTn in the CKD population remains unclear, the review will also evaluate studies attempting to explain whether the source of cTn is from increased cardiac production versus decreased renal clearance. Further longitudinal studies are required in order to bridge the gap between the prognostic importance of elevated cTn and clinical management to prevent symptomatic cardiac disease.
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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
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
ReviewHow acute changes in cardiac troponin concentrations help to handle the challenges posed by troponin elevations in non-ACS-patients.
Cardiac troponins (cTn) I and T are organ-specific, but not disease specific biomarkers. Although acute myocardial infarction (AMI) is the most important cause of cTn elevation, other cardiac disorders as well as primarily noncardiac disorders with cardiac involvement often are also associated with cardiomyocyte injury. Levels of cTn should be interpreted as quantitative markers of cardiomyocyte injury with the likelihood of AMI increasing with the level of cTn. ⋯ Two caveats apply to the diagnostic use of cTn changes. First, patients with AMI may show no or only a minimal change when assessed around the peak of cTn release. Second, in addition to AMI, several other acute cardiac conditions including tachyarrhythmias, myocarditis, hypertensive crisis, and Takotsubo cardiomyopathy also may present with substantial cTn changes.
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Clinical biochemistry · Mar 2015
ReviewEffectiveness of practices for improving the diagnostic accuracy of Non ST Elevation Myocardial Infarction in the Emergency Department: A Laboratory Medicine Best Practices™ systematic review.
This article is a systematic review of the effectiveness of four practices (assay selection, decision point cardiac troponin (cTn) threshold selection, serial testing, and point of care testing) for improving the diagnostic accuracy Non-ST-Segment Elevation Myocardial Infarction (NSTEMI) in the Emergency Department. ⋯ The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention/the Agency for Toxic Substances and Disease Registry (CDC/ATSDR).