Defining high-sensitivity cardiac troponin concentrations in the community.

Background: High-sensitivity cardiac troponin (hs-cTn) assays are now available that can detect measurable troponin in significantly more individuals in the general population than conventional assays. The clinical use of these hs-cTn assays depends on the development of proper reference values. Therefore, our objective was to define hs-cTnI reference values and determinants in the general community, in a healthy reference cohort, and in subsets with diseases.

Harmonisation of Measurement Procedures: how do we get it done?

Clinical laboratory measurement results must be comparable among different measurement procedures, different locations and different times in order to be used appropriately for identifying and managing disease conditions. Harmonisation in the broad sense is the overall process of achieving comparability of results among clinical laboratory measurement procedures that measure the same measurand. The term standardisation is used when comparable results among measurement procedures are based on calibration traceability to SI using a reference measurement procedure of the highest available order.

Measurement of multiple biomarkers in advanced stage heart failure patients treated with pulmonary artery catheter guided therapy.

Introduction: This study was carried out to investigate the prognostic utility of biomarkers in advanced stage heart failure (HF) patients requiring ICU admission for pulmonary artery catheter (PAC) guided therapy.

Methods: Thirty patients admitted to an ICU for PAC guided HF therapy were enrolled; concentrations of soluble ST2 (sST2), highly sensitive troponin I, an experimental ultrasensitive troponin I, amino-terminal pro-B type natriuretic peptide, cystatin C, and myeloperoxidase were measured over the first 48 hours. Outcomes included response of filling pressures and hemodynamics to tailored therapy and 90-day event-free survival (death, left ventricular assist device implantation, transplant).

Functional sensitivity of seven automated thyroid stimulating hormone immunoassays.

Background: Serum thyroid stimulating hormone (TSH) measurements are useful for detecting clinical and subclinical primary hypo- and hyperthyroidism in ambulatory patients. For diagnosis of hyperthyroidism, the functional sensitivity (FS) is an important performance criterion, and current guidelines recommend an FS of ≤0.02 m IU/l for "third" generation performance.

Roadmap for harmonization of clinical laboratory measurement procedures.

Results between different clinical laboratory measurement procedures (CLMP) should be equivalent, within clinically meaningful limits, to enable optimal use of clinical guidelines for disease diagnosis and patient management. When laboratory test results are neither standardized nor harmonized, a different numeric result may be obtained for the same clinical sample. Unfortunately, some guidelines are based on test results from a specific laboratory measurement procedure without consideration of the possibility or likelihood of differences between various procedures.

Plasma and dietary magnesium and risk of sudden cardiac death in women.

Background: Magnesium has antiarrhythmic properties in cellular and experimental models; however, its relation to sudden cardiac death (SCD) risk is unclear.

Objective: We prospectively examined the association between magnesium, as measured in diet and plasma, and risk of SCD.

Design: The analysis was conducted within the Nurses' Health Study.

Amino-terminal pro-B-type natriuretic peptide and high-sensitivity C-reactive protein as predictors of sudden cardiac death among women.

Background: Plasma concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP) have been found to predict risk of sudden cardiac death (SCD) in patients with known cardiac disease, and C-reactive protein levels have been found to predict risk among apparently healthy men. However, there are no data on SCD risk prediction for either of these markers in a population of women unselected on the basis of cardiovascular disease.

Methods And Results: In a prospective, nested, case-control analysis within the 121,700-participant Nurses' Health Study, 99 cases of definite or probable SCD were identified and matched to 294 controls.