Clinical chemistry
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Comparative Study
Comparison of serum creatinine and cystatin C for early diagnosis of contrast-induced nephropathy after coronary angiography and interventions.
The diagnostic accuracy of serum creatinine and cystatin C (Cys) as early predictors of contrast-induced nephropathy (CIN) has been debated. We investigated the diagnostic sensitivities, diagnostic specificities, and variations from baseline for serum creatinine and Cys in CIN. ⋯ Variations from the serum creatinine baseline offer better diagnostic accuracy for predicting CIN at an earlier stage than similar variations in Cys. An additional diagnostic value of Cys over the determination of serum creatinine in the setting of CIN was not observed.
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Comparative Study
Troponin T measurements by high-sensitivity vs conventional assays for risk stratification in acute dyspnea.
Cardiac troponin T measured by a high-sensitivity assay (hs-cTnT) recently proved to be of prognostic value in several populations. The hs-cTnT assay may also improve risk stratification in acute dyspnea. ⋯ hs-cTnT is associated with mortality in patients presenting with acute dyspnea. hs-cTnT concentrations provide additional prognostic information to cTnT and NT-proBNP testing in patients with cTnT concentrations below the detection limit. In particular, the hs-cTnT cutoff of 0.016 μg/L enables identification of low-risk patients.
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We evaluated kinetic changes of high-sensitivity cardiac troponin T (hs-cTnT) in patients with acute coronary syndrome (ACS) and patients with hs-cTnT increases not due to ACS to rule in or rule out non-ST-segment elevation myocardial infarction (STEMI). ⋯ Absolute δ changes appear superior to relative δ changes in discriminating non-STEMI. A rise or fall of at least 9.2 ng/L in the entire study population and 6.9 ng/L in selected ACS patients seems adequate to rule-out non-STEMI. However, δ-values are useful to rule-in non-STEMI only in a specific ACS population.
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Cardiac troponins I (cTnI) and T (cTnT) have received international endorsement as the standard biomarkers for detection of myocardial injury, for risk stratification in patients suspected of acute coronary syndrome, and for the diagnosis of myocardial infarction. An evidence-based clinical database is growing rapidly for high-sensitivity (hs) troponin assays. Thus, clarifications of the analytical principles for the immunoassays used in clinical practice are important. ⋯ This review raises important points regarding cTnI and cTnT assays and their reference limits and specifically addresses hs assays used to measure low concentrations (nanograms per liter or picograms per milliliter). Recommendations are made to help clarify the nomenclature. The review also identifies further challenges for the evolving science of cardiac troponin measurement. It is hoped that with the introduction of these concepts, both laboratorians and clinicians can develop a more unified view of how these assays are used worldwide in clinical practice.
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Glial fibrillary acidic protein (GFAP) is a biomarker candidate indicative of intracerebral hemorrhage (ICH) in patients with symptoms of acute stroke. GFAP is released rapidly in the presence of expanding intracerebral bleeding, whereas a more gradual release occurs in ischemic stroke. In this study the diagnostic accuracy of plasma GFAP was determined in a prospective multicenter approach. ⋯ Plasma GFAP analysis performed within 4.5 h of symptom onset can differentiate ICH and ischemic stroke. Studies are needed to evaluate a GFAP point-of-care system that may help optimize the prehospital triage and management of patients with symptoms of acute stroke.