scholarly journals Analytical Validation of a High-Sensitivity Cardiac Troponin T Assay

2010 ◽  
Vol 56 (2) ◽  
pp. 254-261 ◽  
Author(s):  
Evangelos Giannitsis ◽  
Kerstin Kurz ◽  
Klaus Hallermayer ◽  
Jochen Jarausch ◽  
Allan S Jaffe ◽  
...  

Abstract Background: We report the development of a novel high-sensitivity cardiac troponin T (hs-cTnT) assay, a modification of the Roche fourth-generation cTnT assay, and validation of the analytical performance of this assay. Methods: Validation included testing of analytical sensitivity, specificity, interferences, and precision. We established the 99th percentile cutoff from healthy reference populations (n = 616). In addition, we studied differences in time to a positive result when using serial measurements of hs-cTnT vs cTnT in patients with a confirmed diagnosis of non-ST elevation myocardial infarction (non-STEMI). Results: The hs-cTnT assay had an analytical range from 3 to 10 000 ng/L. At the 99th percentile value of 13.5 ng/L, the CV was 9% using the Elecsys® 2010 analyzer. The assay was specific for cTnT without interferences from human cTnI or cTnC, skeletal muscle TnT, or hemoglobin concentrations up to 1000 mg/L, above which falsely lower values would be expected. When the assay was evaluated clinically, a hs-cTnT higher than the 99th percentile concentration identified a significantly higher number of patients with non-STEMI on presentation (45 vs 20 patients, P = 0.0004) compared with cTnT, and a final diagnosis of non-STEMI was made in 9 additional patients (55 vs 46 patients, P = 0.23) after serial sampling. Time to diagnosis was significantly shorter using hs-cTnT compared with cTnT [mean 71.5 (SD 108.7) min vs 246.9 (82.0) min, respectively; P < 0.01]. Conclusions: The analytical performance of hs-cTnT complies with the ESC-ACCF-AHA-WHF Global Task Force recommendations for use in the diagnosis of MI.

2010 ◽  
Vol 29 (4) ◽  
pp. 274-281 ◽  
Author(s):  
Jochen Jarausch

Diagnostic and Prognostic Information Provided by a High Sensitivity Assay for Cardiac Troponin TCardiac troponins (cTns) are the preferred biomarkers for the diagnosis of acute myocardial infarction, assessment of risk and prognosis, and for determination of antithrombotic and revascularization strategy in patients with acute coronary syndromes. The implementation of high sensitivity cTn assays into the clinical routine has increased the number of patients diagnosed with myocardial infarction. In addition, the number of patients with elevated cTn levels that cannot be explained by acute ischemic injury was increased, which is observed in patients with chronic heart disease and other nonischemic cardiac injury or in patients with impaired renal function. The new definition of myocardial infarction provides support for the interpretation of elevated cTn measured with high sensitivity cTn assays in patients with suspected acute coronary syndrome. This review will summarize clinical studies with the recently introduced high sensitivity cTnT assay (TnT hs) with reference to recent experience with high sensitivity cTn assays in general.


2012 ◽  
Vol 58 (6) ◽  
pp. 1049-1054 ◽  
Author(s):  
Christoph Liebetrau ◽  
Helge Möllmann ◽  
Holger Nef ◽  
Sebastian Szardien ◽  
Johannes Rixe ◽  
...  

Abstract BACKGROUND The release kinetics of cardiac troponin T measured with conventional vs high-sensitivity cardiac troponin T (hs-cTnT) assays in patients with acute myocardial infarction (AMI) is difficult to establish. METHODS We analyzed the release kinetics of cTnT measured by fourth generation and high-sensitivity assays, creatine kinase-MB (CK-MB), and myoglobin in patients with hypertrophic obstructive cardiomyopathy undergoing transcoronary ablation of septal hypertrophy (TASH), a model of AMI. Consecutive patients (n = 21) undergoing TASH were included. Serum and EDTA-plasma samples were collected before and at 15, 30, 45, 60, 75, 90, and 105 min, and 2, 4, 8, and 24 h after TASH. RESULTS cTnT concentrations measured by the hs assay were significantly increased at 15 min [21.4 ng/L, interquartile range (IQR) 13.3–39.7 ng/L vs 11.3 ng/L, IQR 6.0–18.8 ng/L at baseline; P = 0.031]. In comparison, cTnT concentrations measured by the conventional fourth generation assay increased significantly at 60 min (30.0 ng/L, IQR 20.0–30.0 ng/L vs <10.0 ng/L, IQR <10.0–10.0 ng/L; P < 0.01), CK-MB at 90 min (8.4 μg/L, IQR 6.9–14.4 μg/L vs 0.9 μg/L, IQR 0.4–1.1 μg/L; P < 0.01), and myoglobin at 30 min (188.0 μg/L, IQR 154.0–233.0 μg/L vs 38.0 μg/L, IQR 28.0–56.0; P < 0.01). CONCLUSIONS cTnT concentrations measured by the hs assay were significantly increased after TASH at all of the time points, with a doubling at 15 min after induction of AMI, confirming earlier evidence of myocardial injury compared to the fourth generation cTnT assay and CK-MB and myoglobin.


2017 ◽  
Vol 63 (2) ◽  
pp. 542-551 ◽  
Author(s):  
Matthias Mueller-Hennessen ◽  
Christian Mueller ◽  
Evangelos Giannitsis ◽  
Moritz Biener ◽  
Mehrshad Vafaie ◽  
...  

Abstract BACKGROUND Guidelines for diagnosing acute myocardial infarction (AMI) recommend adding kinetic changes to the initial cardiac troponin (cTn) blood concentration to improve AMI diagnosis. We hypothesized that kinetic changes may not be required in patients presenting with highly abnormal cTn. METHODS Patients presenting with suspected AMI to the emergency department were enrolled in a prospective diagnostic study. We assessed the positive predictive value (PPV) of initial high-sensitivity cardiac troponin T (hs-cTnT) blood concentrations alone and in combination with kinetic changes for AMI. Predefined relative changes (δ change of ≥20%) and absolute changes (Δ change ≥9.2 ng/L) within different time intervals (1 h, 2 h, and 4–14 h after presentation) were assessed. The final diagnosis was adjudicated by 2 independent cardiologists. RESULTS Among 1282 patients, 213 (16.6%) patients had a final diagnosis of AMI. For AMI prediction, PPVs increased from 48.8% for an initial hs-cTnT >14 ng/L to 87.2% for >60 ng/L, whereas PPVs remained unchanged for higher hs-cTnT concentrations at baseline (87.1% for both >80 ng/L and >100 ng/L). With addition of 20% relative Δ change, PPVs were not further improved in patients with baseline hs-cTnT >80 ng/L using the 1-h (84.0%) and 2-h (88.9%) intervals, and only minimally when extending the interval to 4–14 h (91.2% for >80 ng/L and 90.4% for >100 ng/L, respectively). Similar findings were observed when applying absolute changes. CONCLUSIONS In chest pain patients with highly abnormal hs-cTnT concentrations at presentation, subsequent blood draws may not be required, as they do not provide incremental diagnostic value for prediction of AMI diagnosis.


2012 ◽  
Vol 58 (1) ◽  
pp. 246-256 ◽  
Author(s):  
Nora Schaub ◽  
Tobias Reichlin ◽  
Christophe Meune ◽  
Raphael Twerenbold ◽  
Philip Haaf ◽  
...  

Abstract BACKGROUND Plaque erosion and plaque rupture occur early in the pathophysiology of acute myocardial infarction (AMI). We hypothesized that markers of plaque instability might be useful in the early diagnosis and risk stratification of AMI. METHODS In this multicenter study, we examined 4 markers of plaque instability, myeloperoxidase (MPO), myeloid-related protein 8/14 (MRP-8/14), pregnancy-associated plasma protein-A (PAPP-A), and C-reactive protein (CRP) in 398 consecutive patients presenting to the emergency department with acute chest pain and compared them to normal and high-sensitivity cardiac troponin T (cTnT and hs-cTnT). The final diagnosis was adjudicated by 2 independent cardiologists. Primary prognostic end point was death during a median follow-up of 27 months. RESULTS The adjudicated final diagnosis was AMI in 76 patients (19%). At emergency department presentation, concentrations of all 4 biomarkers of plaque instability were significantly higher in patients with AMI than in patients with other diagnoses. However, their diagnostic accuracy as quantified by the area under the ROC curve (AUC) was low (MPO 0.63, MRP-8/14 0.65, PAPP-A 0.62, CRP 0.59) and inferior to both normal and high-sensitivity cardiac troponin T (cTnT 0.88, hs-cTnT 0.96; P < 0.001 for all comparisons). Thirty-nine patients (10%) died during follow-up. Concentrations of MPO, MRP-8/14, and CRP were higher in nonsurvivors than in survivors and predicted all-cause mortality with moderate accuracy. CONCLUSIONS Biomarkers of plaque instability do not seem helpful in the early diagnosis of AMI but may provide some incremental value in the risk stratification of patients with acute chest pain.


Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Yasuyuki Honda ◽  
Yejin Mok ◽  
Junichi Ishigami ◽  
Kellan E Ashley ◽  
Ron C Hoogeveen ◽  
...  

Background: High-sensitivity cardiac troponin T (TnT) is a potent predictor of cardiovascular disease (CVD) in the general population. Recently, the US FDA has approved Roche fifth generation (Gen 5) TnT assay (more sensitive than the fourth generation [Gen 4] TnT assay). Since many previous epidemiological studies used Gen 4 TnT, it is important to characterize the association of Gen 5 TnT with major CVD events. Methods: We first assessed correlation of Gen 5 vs. Gen 4 TnT in a subsample of 91 participants. Then, as the main analysis, we examined the association of Gen 5 TnT at visit 3 (1993-1995) with major CVD events (coronary heart disease [CHD], stroke, heart failure [HF], and peripheral artery disease [PAD]). Gen 5 TnT was categorized as <6 (limit of quantification), 6-<8, 8-<14, 14-<19, and ≥19 ng/L. CHD and stroke events were adjudicated whereas HF and PAD were based on hospitalization codes. We also conducted a subgroup analysis by prevalent CVD at baseline. Results: Gen 5 TnT and Gen 4 TnT had a correlation coefficient of 0.98 (0.88 after excluding outliers >3SD). Of 11,979 participants (mean age 60 [SD 6] years, 1,840 [15%] with prevalent CVD), 5,856 (49%) participants had quantifiable levels of TnT. During a median follow-up of 22.1 years, there were 1,850 CHD events, 1,075 stroke events, 2,908 HF cases, and 571 PAD cases. Gen 5 TnT showed a robust dose response association with each CVD type, with adjusted hazard ratio 2-4 for TnT ≥19 (vs.<6) ng/L ( Table ). Even the category 6-<8 ng/L showed significantly elevated risk for all outcomes except stroke. The associations were stronger for HF and PAD than CHD or stroke (all p-values using seemingly unrelated regression <0.001). The associations were similar regardless of baseline CVD status. Conclusions: Gen 5 TnT was highly correlated with Gen 4 TnT and gave quantifiable values in half middle-aged adults. Gen 5 TnT was robustly associated with major CVD events (especially HF and PAD) in the general population, supporting its usefulness in epidemiological research and clinical practice.


Author(s):  
Eloisa Lopez-Calle ◽  
Pamela Espindola ◽  
Juergen Spinke ◽  
Sascha Lutz ◽  
Alfons Nichtl ◽  
...  

AbstractBackground:A multitude of troponin assays for the point-of-care (POC) have been developed showing a lack of analytical sensitivity and precision. We present a new platform solution for the high-sensitivity detection of cardiac troponin T (cTnT) in a 30 μL whole blood sample with a turnaround time of 11 min.Methods:The immunoassay was completely run in a ready-to-use plastic disposable, a centrifugal microfluidic disc with fully integrated reagents. After the sample application, the assay was automatically processed by separating the cellular blood components via centrifugation, followed by incubation of a defined volume from the generated plasma with the immunoreagents. The fluorescence in the signal zone of a membrane was measured after its washing for the cTnT quantitation.Results:A calibration curve, measured in whole blood samples spiked with native human cTnT, was generated covering a range up to a concentration of approximately 8300 ng/L. The lower detection limit was determined to be 3.0 ng/L. At a concentration of 14 ng/L, the 99th percentile value from the high-sensitivity cardiac troponin T (hs-cTnT) assay in the ElecsysConclusions:The described technology shows that an analytical performance for a highly sensitive determination of cTnT can be achieved in a POC setting.


Author(s):  
Chen Dongxu ◽  
Zhou Yannan ◽  
Yang Yilin ◽  
Yao Chenling ◽  
Gu Guorong ◽  
...  

Abstract Objectives A rapid 0 h/1 h algorithm using high-sensitivity cardiac troponin T (hs-cTnT) for rule-out and rule-in of non-ST-segment elevation myocardial infarction (NSTEMI) is recommended by the European Society of Cardiology. We aim to prospectively evaluate the diagnostic performance of the algorithm in Chinese Han patients with suspected NSTEMI. Methods In this prospective diagnostic cohort study, 577 patients presenting to the emergency department with suspected NSTEMI and recent (<12 h) onset of symptoms were enrolled. The levels of serum hs-cTnT were measured on admission, 1 h later and 4–14 h later. All patients underwent the initial clinical assessment and were triaged into three groups (rule-out, rule-in and observe) according to the 0 h/1 h algorithm. The major cardiovascular events (MACE) were evaluated at the 7-day and 30-day follow-ups. Results Among 577 enrolled patients, NSTEMI was the final diagnosis for 106 (18.4%) patients. Based on the hs-cTnT 0 h/1 h algorithm, 148 patients (25.6%) were classified as rule-out, 278 patients (48.2%) as rule-in and 151 patients (26.2%) were assigned to the observe group. The rule-out approach resulted in a sensitivity of 100% and negative predictive value of 100%. The rule-in approach resulted in a specificity of 62.9% [95% CI (58.5–67.2%)] and positive predictive value of 37.1% [95%CI (31.3–42.8%)]. No MACE was observed in the rule-out group within 30-day follow-up. Conclusions The hs-cTnT 0 h/1 h algorithm is a safe tool for early rule-out of NSTEMI, while probably not an effective strategy for accurate rule-in of NSTEMI in Chinese Han population.


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