Clinical chemistry
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The definition of acute myocardial infarction (AMI) requires a rise and/or fall in troponin with 1 or more results ≥99th percentile of the reference range. How much troponin must change has not been specified. We ascertained whether dynamic changes (δ) in high-sensitivity troponin T (hs-TnT) improved diagnostic and prognostic test performance in the emergency department. ⋯ Diagnostic specificity of hs-cTnT improved with the use of a δ ≥20% in those patients with concentrations ≥99th percentile, but at a cost of a large reduction in sensitivity. Diagnostic sensitivity improved with the use of a δ ≥20% in patients with 0-2-h concentrations <99th percentile. Both approaches may be required for optimum rule-in and rule-out strategies, respectively. The δ criteria seem to be less useful for medium-term risk stratification.
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Emerging technologies for rapid identification of microbes demonstrate a shift from traditional biochemical and molecular testing algorithms toward methods using mass spectrometry (MS) for the semiquantitative analysis of microbial proteins and genetic elements. This study was performed to assess the diagnostic accuracy of 2 such technologies, PCR-electrospray ionization (ESI)/MS and MALDI-TOF/MS, with respect to phenotypic and biochemical profiling as a reference standard method. A positive challenge set of blood culture bottles was used to compare PCR-ESI/MS and MALDI-TOF/MS performance on a matched set of samples. ⋯ Our results demonstrate that PCR-ESI/MS and MALDI-TOF/MS are equivalent in their ability to characterize bloodstream infections with respect to the reference standard, and highlight key differences in the methods that allow for each method to have a unique niche as a tool for rapid identification of microbes in blood cultures.
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Multicenter Study
Prognostic utility of ST2 in patients with acute dyspnea and preserved left ventricular ejection fraction.
Soluble ST2 (sST2), an interleukin-1 receptor family member, is an emerging risk indicator for patients with cardiovascular disease. We evaluated the prognostic role of sST2 for patients presenting to the emergency department with acute dyspnea, with a focus on those with preserved left ventricular ejection fraction (LVEF ≥50%), as risk stratification is often most complex in this subgroup. ⋯ sST2 is a strong predictor of mortality in patients presenting with acute dyspnea, particularly those with preserved LVEF, and may be useful for triage and risk stratification of this challenging group.
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To develop methods for systematically reviewing evidence for identifying effective laboratory medicine (LM) practices associated with improved healthcare quality outcomes. ⋯ Adapting and developing methods from validated systems and applying them to systematically review and evaluate practices in LM by using published and unpublished studies is feasible. With these methods, evidence from quality improvement studies can be systematically synthesized and summarized to identify effective LM practices. Practical and scientifically validated demonstration of a positive impact on outcomes ensures that practitioners, policy makers, and decision makers at all levels have the evidence needed for improving healthcare quality and public health.
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Vitamin B₁₂ deficiency is common among the elderly, and early detection is clinically important. However, clinical signs and symptoms have limited diagnostic accuracy and there is no accepted reference test method. ⋯ This study supports the use of holoTC as the first-line diagnostic procedure for vitamin B₁₂ status.