High-sensitivity troponin T and I in patients suspected of acute myocardial infarction.

Measurement of cardiac troponin (cTn) is the cornerstone in the diagnosis of myocardial infarction (MI). Potential disparities in concentrations of cTn, trajectories and mortality, following initial measurement warrant further investigation. Such data may guide clinicians treating patients suspected of MI. Plasma concentrations of cTnT and cTnI were measured in 503 consecutive patients at Aarhus University Hospital between June 13th and June 27th, 2019. cTnT was measured with the Roche cobas® E602 hs-cTnT assay, while cTnI was measured with the Siemens ADVIA Centaur® XPT hs-cTnI assay. Analytical agreement was determined based on assay-specific 99th percentiles. Medical records were reviewed for adjudication of the MI diagnosis. MI was the final diagnosis in 65 patients (12.9%) and the analytical agreement between cTnT and cTnI assays was 95.2%. For patients diagnosed with MI, cTnI reached higher peak concentrations in shorter time, compared to cTnT. All-cause mortality risk increased with increasing levels of both biomarkers. In this study, the analytical agreement of two cTn assays was high. However, some disparities in troponin trajectories were observed.

Non-cardiac causes of troponin elevation.

With the increased sensitivity of the newest cardiac troponin assays, the risk of false positive cardiac troponin measurements has also increased. As summarised in this review, there are multiple possible causes of cardiac troponin release including several non-cardiac illnesses, particularly kidney disease. Further, there is a risk of analytical interference in which case repeated measurements with a different assay is a good tool. When there is a discrepancy between troponin measurement and clinical presentation of the patient, the clinician should consider the possibility of analytical interference.

Existing Data Sources in Clinical Epidemiology: Laboratory Information System Databases in Denmark.

Routine biomarker results from hospital laboratory information systems, covering hospitals and general practitioners, in Denmark are available to researchers through access to the regional Clinical Laboratory Information System Research Database at Aarhus University and the nationwide Register of Laboratory Results for Research. This review describes these two data sources. The laboratory databases have different geographical and temporal coverage. They both include individual-level biomarker results that are electronically transferred from laboratory information systems. The biomarker results can be linked to all other Danish registries at the individual level, using the unique identifier, the CPR number. The databases include variables such as the CPR number, date and time (hour and minute) of sampling, NPU code, and name of the biomarker, identification code for the laboratory and the requisitioner, the test result with the corresponding unit, and the lower and upper reference limits. Access to the two databases differs since they are hosted by two different institutions. Data cannot be transferred outside Denmark, and direct access is provided only to Danish institutions. It is concluded that access to data on routine biomarkers expands the detailed biological and clinical information available on patients in the Danish healthcare system. The full potential is enabled through linkage to other Danish healthcare registries.

The effect of vitamin D3 supplementation on markers of cardiovascular health in hyperparathyroid, vitamin D insufficient women: a randomized placebo-controlled trial.

PURPOSE: Emerging data supports an association between parathyroid hormone (PTH) and aldosterone. It has been speculated, that potential adverse cardiovascular effects of vitamin D insufficiency may partly be caused by the development of secondary hyperparathyroidism with increased activity of the renin-angiotensin-aldosterone system (RAAS). We aimed to investigate the effect of normalizing vitamin D status and/or reducing PTH levels on RAAS activity and other markers of cardiovascular health. METHODS: In a double-blinded study during wintertime, we randomized 81 healthy postmenopausal women with secondary hyperparathyroidism (PTH > 6.9 pmol/l) and 25-hydroxy-vitamin D (25(OH)D) levels < 50 nmol/l to 12 weeks of treatment with vitamin D3 70 µg/day (2800 IU/day) or identical placebo. Markers of cardiovascular health were defined as changes in the plasma RAAS, glycated hemoglobin, lipids, and lipoproteins, blood pressure, vascular stiffness, heart rate, and cardiac conductivity. RESULTS: Compared to placebo, vitamin D3 treatment significantly increased plasma levels of 25(OH)D and 1,25(OH)2D by 230% (95% CI: 189-272%) and 58% (190-271%), respectively. Vitamin D3 treatment reduced PTH by 17% (11-23%), but did not reduce RAAS activity. Compared to placebo, vitamin D3 treatment increased plasma levels of high-density lipoproteins (HDL) by 4.6% (0.12-9.12%), but did not affect other measured indices. CONCLUSIONS: Vitamin D3 supplementation normalized vitamin D levels and reduced PTH. The supplement increased levels of HDL, but had no effects on RAAS activity or other indices of cardiovascular health.

[Dapsone-induced decrease in the HbA(1c) level may cause artefacts in diabetic control]. / Dapsoninduceret fald i HbA(1c) kan give et falskt billede af diabeteskontrollen.

Glycated haemoglobin (HbA(1c)) level is used to monitor glycaemic control in diabetic patients, and has recently been included as a diagnostic factor for type 2 diabetes mellitus (DM). A 50-year-old male with well-controlled type 1 DM, Mb Addison and coeliac disease was diagnosed with dermatitis herpetiformis and treated with dapsone. Subsequently, the patient presented a pronounced drop in HbA(1c) levels without changes in blood glucose levels. S-fructosamine values were in agreement with the previous stable HbA(1c) values. Blood analyses showed inappropriately low HbA(1c) values due to mild haemolysis and shortening of erythrocyte lifetime without anaemia.

Quantitative point-of-care troponin T measurement for diagnosis and prognosis in patients with a suspected acute myocardial infarction.

Improvement of prehospital triage is essential to ensure rapid management of patients with acute myocardial infarction (AMI). This study evaluates the feasibility of prehospital quantitative point-of-care cardiac troponin T (POC-cTnT) analysis, its ability to identify patients with AMI, and its capacity to predict mortality. The study was performed in the Central Denmark Region from May 2010 to May 2011. As a supplement to electrocardiography, a prehospital POC-cTnT measurement was performed by a paramedic in patients with suspected AMI. AMI was diagnosed according to the universal definition of myocardial infarction using the ninety-ninth percentile upper reference level as diagnostic cut point. The paramedics performed POC-cTnT measurements in 985 subjects with a symptom duration of 70 minutes (95% CI, 35 to 180); of whom, 200 (20%) had an AMI. The prehospital sample was obtained 88 minutes (range, 58 to 131) before the sample made on admission to the hospital. The sensitivity for detection of patients with an AMI was 39% (95% CI, 32% to 46%) and the diagnostic accuracy of the POC-cTnT values was 0.67 (95% CI, 0.64 to 0.71). Adjusted survival analysis showed a strong significant association between elevated prehospital POC-cTnT level above the detection level of 50 ng/L and mortality in patients with a suspected AMI irrespective of whether an AMI was diagnosed. In conclusion, large-scale quantitative prehospital POC-cTnT testing by paramedics is feasible. An elevated prehospital POC-cTnT value contains diagnostic information and is highly predictive of mortality in patients with a suspected AMI.