High-sensitivity troponin assays: analytical and clinical aspects

2016 ◽  
Vol 51 (4) ◽  
pp. 315-320
Author(s):  
Magdalena Krintus

Cardiac troponins are considered the most sensitive and specific biomarkers for the diagnosis of acute coronary syndromes (ACS). According to the Third Universal Definition of Acute Myocardial Infarction, the diagnosis requires a rise / or fall of troponin concentration with at least one value exceeding the 99th percentile upper reference limit (URL) in a reference population with the coexistence of clinical symptoms of ischemia. The introduction of highly sensitive assays has resulted in lower detection limits for the concentration of troponin, allowing for early diagnosis of, as well as the detection of quantifiable concentrations of this biomarker in healthy subjects. According to current guidelines, the use of high-sensitivity tests can shorten the time required to make clinical decisions from the current 3-6 hours to 1-2 hours. The use of highly sensitive troponin assays also carries other potential benefits associated with their predictive value, as well as challenges that include reduced specificity for myocardial infarction, lack of standardization or the presence of biological variability. Given the increasing availability of new, highly sensitive troponin assays we should be aware that their increased analytical sensitivity and precision is accompanied by accurate clinical assessment of the patient, and takes into account other non-cardiac causes of their increased concentrations.

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 384 ◽  
Author(s):  
Zhiliang Zhang ◽  
Tiantian Si ◽  
Jun Liu ◽  
Guowei Zhou

The rapid sampling and efficient collection of target molecules from a real-world surface is fairly crucial for surface-enhanced Raman scattering (SERS) to detect trace pesticide residues in the environment and in agriculture fields. In this work, a versatile approach was exploited to fabricate a flexible SERS substrate for highly sensitive detection of carbaryl pesticides, using in-situ grown silver nanoparticles (AgNPs)on non-woven (NW) fabric surfaces based on mussel-inspired polydopamine (PDA) molecules. The obtained NW@PDA@AgNPs fabrics showed extremely sensitive and reproducible SERS signals toward crystal violet (CV) molecules, and the detection limit was as low as 1.0 × 10−12 M. More importantly, these NW@PDA@AgNPs fabrics could be directly utilized as flexible SERS substrates for the rapid extraction and detection of trace carbaryl pesticides from various fruit surfaces through a simple swabbing approach. It was identified that the detection limits of carbaryl residues from apple, orange, and banana surfaces were approximately decreased to 4.02 × 10−12, 6.04 × 10−12, and 5.03 × 10−12 g, respectively, demonstrating high sensitivity and superior reliability. These flexible substrates could not only drastically increase the collection efficiency from multifarious irregular-shaped matrices, but also greatly enhance analytical sensitivity and reliability for carbaryl pesticides. The fabricated flexible and multifunctional SERS substrates would have great potential to trace pesticide residue detection in the environment and bioscience fields.


TECHNOLOGY ◽  
2014 ◽  
Vol 02 (03) ◽  
pp. 200-205 ◽  
Author(s):  
Shyam Sundhar Bale ◽  
Gavrielle Price ◽  
Monica Casali ◽  
Nima Saeidi ◽  
Abhinav Bhushan ◽  
...  

Type 1 Diabetes Mellitus (T1DM) is a T-cell mediated autoimmune disease in which deterioration of insulin producing pancreatic β-cells leads to a state of insulin deficiency. It has been shown that the clinical symptoms of T1DM are preceded by presence of islet cell autoantibodies (ICA) in serum. Radioimmunoassay (RIA) based detection of ICA are the current gold standard for diagnosis of T1DM. While the onset of hyperglycemia is an indicator of onset of T1DM, detection of ICA within the serum is important to differentiate T1DM from ketogenic Type 2 Diabetes (T2D) and Maturity Onset Diabetes of the Young (MODY). Due to their limited range of sensitivity, however, RIA cannot detect ICA at low concentrations in serum which could lead to delay in proper diagnosis and treatment. In addition, the use of radioactive species presents major disadvantages including exposure, waste removal, need for specialized licensed facilities to conduct the tests and the time required for the test (> 24 hours). To overcome these limitations, we have developed a rapid, highly sensitive, fluorescent and microsphere-based assay technique using Rolling Circle Amplification (RCA), to profile T1DM marker antibodies in serum. This assay utilizes the ability of RCA to detect very small amounts of DNA coupled with microsphere-immobilization resulting in an assay which is at least 50 times more sensitive than RIA. Further, this assay method requires very low volume of sample (5 μL), and can be easily adapted to detect other autoantibodies at similar sensitivities while reducing the assay time to ~6 hours. This powerful technique could enable detection of T1DM markers much earlier than current methods and enable earlier intervention to deter the progression of disease. In addition, the modularity of this assay would have implications for enhancing the sensitivities of any standard ELISA technique.


2018 ◽  
Vol 96 (1) ◽  
pp. 25-29
Author(s):  
N. N. Borovkov ◽  
Natalya A. Golitsyna

Aim. Study the immediate clinical significance of determination of highly sensitive troponin (high sensitive cardiac troponin - hscTn) in the early diagnosis of acute myocardial infarction (AMI). Material and methods. The analysis of nosological diagnosis in 92 patients with acute coronary syndrome (ACS), urgently hospitalized in the coronary care unit of the Nizhny Novgorod regional hospital. N.A. Semashko. The time from the moment of development of pain syndrome, hospitalization in a hospital ranged from 40 minutes to 4 hours, averaging 2.5 ± 0.32 hours. During hospitalization of patients in the complex diagnosis of AMI in addition to General clinical examination, ECG was determined by the content hscTn and troponin I. All patients in the hospital was performed selective coronary angiography (SCG). Evaluated the sensitivity, specificity and diagnostic accuracy hscTn in comparison with troponin I. Analysis results were represented as a percentage and using a software package "STATISTICA 10.0" (StatSoft, Inc., USA). Results. AMI is diagnosed in 74% of cases (n=68), and the rest 26% (n=24) unstable (progressive) angina (NS). Transmural myocardial infarction or Q-wave myocardial infarction detected in 54% (n=37) of patients. Intramural myocardial infarction or non Q-wave myocardial infarction - in 46% (n=31). AMI re-seen in 27% (n=18). Importance of the study of both cardiac troponin in the early diagnosis of AMI showed the following. Sensitivity hscTn reached 98%, while troponin I - 88%. Specificity hscTn was 79%, and troponin I, only 66%. Overall diagnostic accuracy hscTn was 92%, troponin I less - 83%). Conclusion. The results of the study indicate a predominant clinical significance hscTn in comparison with troponin I in early diagnosis of AMI in the parameters of sensitivity, specificity and diagnostic accuracy.


2013 ◽  
Vol 61 (10) ◽  
pp. E228 ◽  
Author(s):  
William Parsonage ◽  
Louise Cullen ◽  
Jaimi Greenslade ◽  
Jill Tate ◽  
Jacobus Ungerer ◽  
...  

2021 ◽  
pp. emermed-2020-210812
Author(s):  
Rob Meek ◽  
Louise Cullen ◽  
Zhong Xian Lu ◽  
Arthur Nasis ◽  
Lisa Kuhn ◽  
...  

BackgroundHigh-sensitivity cardiac troponin I (hs-cTnI) assays promise high diagnostic accuracy for myocardial infarction (MI). In an ED where conventional cTnI was in use, we evaluated an assessment pathway using the new Access hsTnI assay.MethodsThis retrospective analysis recruited ED patients with suspected MI between June and September 2019. All patients received routine care with a conventional cTnI assay (AccuTnI +3: limit of detection (LoD) 10 ng/L, 99th centile upper reference limit (URL) 40 ng/L, abnormal elevation cut-point 80 ng/L). Arrival, then 90-minute or 360-minute cTnI levels for low and non-low risk patients, respectively (ED Assessment of Chest pain score) guided diagnosis and disposition which was at treating physician discretion. The same patients had arrival and 90-minute or 180-minute samples drawn for hs-cTnI levels (Access hsTnI: LoD 2 ng/L, 99th centile URL 10 ng/L (females) and 20 ng/L (males); abnormal elevation above the URL and delta >30%). Treating physicians were blinded to the hs-cTnI results. Using the hs-cTnI values, investigators retrospectively assigned likely diagnosis, disposition and likelihood of a 30-day major adverse cardiac event (MACE). Admission was recommended for significantly rising hs-cTnI elevations. The primary objective was to demonstrate an acceptable unexpected 30-day post-discharge MACE rate of <1%. cTnI elevation rates, diagnostic outcomes and ED disposition were also compared between pathways.ResultsFor the 935 patients, unexpected 30-day post-discharge MACE rates were 0/935 (0%, 95% CI 0% to 0.4%) with the conventional or novel pathway. For the high-sensitivity and conventional assays, respectively, abnormal elevation rates were 29% (95% CI 26% to 32%) and 19% (95% CI 17% to 22%), for MI were 9% (95% CI 8% to 11%) and 8% (95% CI 6% to 10%), and for hospital admission were 42% (95% CI 39% to 45%) and 43% (95% CI 40% to 47%).ConclusionThe novel pathway using the Access hsTnI assay has an acceptably low 30-day MACE rate.


Author(s):  
Tanja Zeller ◽  
Francisco Ojeda ◽  
Fabian J. Brunner ◽  
Philipp Peitsmeyer ◽  
Thomas Münzel ◽  
...  

AbstractThe 99th percentile of cardiac troponin levels, determined in a reference population, is accepted as threshold for diagnosis of acute myocardial infarction (AMI). However, there is no common consensus of how to define the reference population. The aim of the present study was to determine 99th percentile reference values, determined by a high-sensitivity assay (hsTnI), according to different health status and cardiovascular risk factor prevalence in a large population-based sample.Troponin I was determined using the Abbott ARCHITECT STAT highly sensitive troponin I immunoassay in 4138 participants of the Gutenberg Health Study.hsTnI was detectable in 81.6% of all individuals. The 99th percentile of the overall population was 27 ng/L. Age and gender had a prominent influence on these values. Exclusion of individuals with elevated natriuretic peptide levels or cardiac abnormalities resulted in lower 99th percentile values, whereas exclusion of individuals with an impaired estimated glomerular filtration rate (eGFR) or with prevalent coronary artery disease/myocardial infarction (CAD/MI) did not result in a meaningful change.Troponin I, measured by a high-sensitivity assay, can be reliably detected in the vast majority of the general population. hsTnI values were dependent on age, gender as well as structural and functional cardiac abnormalities.


Author(s):  
Simona Ferraro ◽  
Alberto Dolci ◽  
Mauro Panteghini

Abstract:The introduction of “highly sensitive” cardiac troponin assays (hsTn) has reinforced the evidence that only serial testing incorporated in running algorithms allows a more accurate diagnosis of acute myocardial infarction. In this report, we consider the available evidence supporting the use of fast track protocols for ruling out and ruling in non-ST elevation myocardial infarction (NSTEMI) and compare it with the content of recently released guideline by the European Society of Cardiology, noting some uncomfortable aspects that need urgent clarification and/or revision. Firstly, the guideline drafters have to reconsider the available evidence that does not permit to assign the same class and level of evidence to the very well-validated 0–3 h algorithm and to the 0–1 h algorithm. In agreement with the validity of available data, the limitations of fast track protocols, in particular of the 0–1 h algorithm for NSTEMI rule-in, calls for caution. Secondly, as the current diagnostics guidance by the UK National Institute for Health and Care Excellence recommends, rapid diagnostic protocols should be performed only using well-validated hsTn; recommending the use of an assay before being commercially available is not fair and scientifically sound.


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