scholarly journals Fluoroenzymometric method to measure cardiac troponin I in sera of patients with myocardial infarction

1996 ◽  
Vol 42 (9) ◽  
pp. 1460-1466 ◽  
Author(s):  
M Zaninotto ◽  
S Altinier ◽  
M Lachin ◽  
P Carraro ◽  
M Plebani

Abstract The aim of our study was to evaluate the clinical relevance of serum troponin I (TnI) as a marker of ischemic myocardial injury by using an automated fluoroenzymometric assay. The reference range for serum TnI was established by measuring serum TnI concentrations in blood from 75 healthy donors. The concentration was then compared with serum creatine kinase (CK) activity, CK-MB mass, and myoglobin concentrations in 20 patients with myocardial infarction diagnosed according to the WHO criteria, 20 patients with chest pain of nonischemic origin, 9 patients with unstable angina, 11 with stable angina, 11 patients with chronic muscular diseases, 6 patients with muscular trauma without chest contusion, and 13 patients with chronic renal disease. We found that: (a) 99% of the blood donors had TnI concentrations <0.26 microgram/L (detection limit of the assay in our study); (b) TnI values in acute myocardial infarction (AMI) patients 4 h after onset of chest pain showed a sensitivity of 0.769 and a specificity of 1.0 at a decisional concentration for AMI of 1 microgram/L, even in the presence of severe skeletal muscle injuries or renal diseases; (c) the increase in TnI concentrations after infarction (interquartile range 3.25-6 h) and the peak occurred later (interquartile range 11.5-24 h) than the rise found in myoglobin and CK-MB, but the increase persisted much longer (>96 h); (d) receiver-operating characteristic curve analysis showed the high diagnostic accuracy of TnI in diagnosing AMI even in patients in whom traditional biochemical markers are adversely influenced by underlying clinical situations.

1993 ◽  
Vol 39 (6) ◽  
pp. 972-979 ◽  
Author(s):  
C Larue ◽  
C Calzolari ◽  
J P Bertinchant ◽  
F Leclercq ◽  
R Grolleau ◽  
...  

Abstract The screening by immunoenzymometric assay (IEMA) of 784 monoclonal antibody (MAb) combinations resulted in the selection of an optimal pair of MAbs for measuring human cardiac troponin I (TnI). Using a one-step IEMA described here, we were able to detect TnI within the range of 0.2-20 micrograms/L in 30 min at room temperature. No cross-reactivity was observed with the skeletal isoforms of troponin up to a concentration of 500 micrograms/L. This assay was used to measure cardiac TnI in the plasma of 43 patients with acute myocardial infarction (AMI). TnI was detected relatively early after the onset of chest pain (4.3 +/- 2.1 h, mean +/- SD); the peak occurred after 12.2 +/- 4.6 h in a population that had undergone fibrinolysis. TnI disappearance was generally observed between 5 and 9 days after the onset of chest pain. No cardiac TnI could be detected in 145 healthy donors or in a control group of 6 patients (with skeletal damage or rhabdomyolysis). This assay allows a specific diagnosis of AMI in its early acute phase, with a high diagnostic specificity and sensitivity.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
F Kahles ◽  
R.W Mertens ◽  
M.V Rueckbeil ◽  
M.C Arrivas ◽  
J Moellmann ◽  
...  

Abstract Background GLP-1 and GLP-2 (glucagon-like peptide-1/2) are gut derived hormones that are co-secreted from intestinal L-cells in response to food intake. While GLP-1 is known to induce postprandial insulin secretion, GLP-2 enhances intestinal nutrient absorption and is clinically used for the treatment of patients with short bowel syndrome. The relevance of the GLP-2 system for cardiovascular disease is unknown. Purpose The aim of this study was to assess the predictive capacity of GLP-2 for cardiovascular prognosis in patients with myocardial infarction. Methods Total GLP-2 levels, NT-proBNP concentrations and the Global Registry of Acute Coronary Events (GRACE) score were assessed at time of admission in 918 patients with myocardial infarction, among them 597 patients with NSTEMI and 321 with STEMI. The primary composite outcome of the study was the first occurrence of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke (3-P-MACE) with a median follow-up of 311 days. Results Kaplan-Meier survival plots (separated by the median of GLP-2 with a cut-off value of 4.4 ng/mL) and univariable cox regression analyses found GLP-2 values to be associated with adverse outcome (logarithmized GLP-2 values HR: 2.87; 95% CI: 1.75–4.68; p<0.0001). Further adjustment for age, sex, smoking, hypertension, hypercholesterolemia, diabetes mellitus, family history of cardiovascular disease, hs-Troponin T, NT-proBNP and hs-CRP levels did not affect the association of GLP-2 with poor prognosis (logarithmized GLP-2 values HR: 2.96; 95% CI: 1.38–6.34; p=0.0053). Receiver operating characteristic curve (ROC) analyses illustrated that GLP-2 is a strong indicator for cardiovascular events and proved to be comparable to other established risk markers (area under the curve of the combined endpoint at 6 months; GLP-2: 0.72; hs-Troponin: 0.56; NT-proBNP: 0.70; hs-CRP: 0.62). Adjustment of the GRACE risk estimate by GLP-2 increased the area under the receiver-operating characteristic curve for the combined triple endpoint after 6 months from 0.70 (GRACE) to 0.75 (GRACE + GLP-2) in NSTEMI patients. Addition of GLP-2 to a model containing GRACE and NT-proBNP led to a further improvement in model performance (increase in AUC from 0.72 for GRACE + NT-proBNP to 0.77 for GRACE + NT-proBNP + GLP-2). Conclusions In patients admitted with acute myocardial infarction, GLP-2 levels are associated with adverse cardiovascular prognosis. This demonstrates a strong yet not appreciated crosstalk between the heart and the gut with relevance for cardiovascular outcome. Future studies are needed to further explore this crosstalk with the possibility of new treatment avenues for cardiovascular disease. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): German Society of Cardiology (DGK), German Research Foundation (DFG)


Author(s):  
Mahir Abdulkadhum Khudhair Alzughaibi ◽  
Ammar Waheeb Obeiad ◽  
Nassar Abdalaema Abdalhadi Mera ◽  
Mohammed Sadeq Hamzah Al-Ruwaiee

Background: Cardiac Troponins-I (CTNI) are myoregulatory polypeptides that control the actin-myosin interface, considered specific to cardiomyocytes. Age and sex variances in the extent of CTNI levels have arisen a recent debatable emphasis. Existing revisions do not display a reliable clinical power of sex-specific CTNI 99th centiles, which actually might mirror procedural aspects. Nevertheless, from a biochemical viewpoint, the trends of sex-specific CTNI 99th centiles seem sensible for the ruling-in of acute myocardial infarction AMI. Vulnerable females may be missed when applying the male sex-specific threshold. This study aimed to determine whether gender differences in CTNI exist in patients with AMI presented with chest pain. Methodology: The study was a cross-sectional, single-center, included 236-patients with AMI diagnosis by cardiologists at Merjan teaching hospital during the period from April to July 2020 from patients attending the hospital for cardiac consultation complaining of acute chest pain suggestive of AMI. Blood analysis had initiated at the time of admission included serum creatinine, blood urea, R/FBS, WBCs, PCV, and serum CTNI. A p-value below 0.05 specifies statistical significance. All statistical bioanalyses had performed by IBM-SPSS, version-25 for Windows. Results: The mean age of participants was 67.5 years, the men were dominant 76.2%. The incidence of DM and hypertension were significantly high and 24.5% of the patients were current smokers. Biochemical serum analysis revealed mean creatinine, urea, sugar, and STI values were 79.8±4.2 mmol/l, 15.9±1.7 mmol/l, 10.9±0.9 mmol/l, and 7.9±0.6 ng/ml separately. Both hypertension and smoking were significantly (p-0.001) more among males compared to the females, which is not the case for the prevalence of DM. The males were heavier significantly than females (p-0.001). Almost, there was no impact of gender on most of the other study variables other than serum TNI levels, which were significantly higher among the males (p-0.001). Conclusion: In patients with AMI presented with acute chest pain, the routine of CTNI in the diagnosis of AMI is based on the patient's gender. The application of gender-dependent cutoff levels for CTNI analyses appears to be highly suggested.


1994 ◽  
Vol 40 (7) ◽  
pp. 1291-1295 ◽  
Author(s):  
J E Adams ◽  
K B Schechtman ◽  
Y Landt ◽  
J H Ladenson ◽  
A S Jaffe

Abstract Although measurement of cardiac troponin I (cTnI) is, in some situations, more specific for detection of cardiac injury than is measurement of the MB isoenzyme of creatine kinase (MBCK), its sensitivity and specificity relative to MBCK for detection of myocardial infarction has not been established. Accordingly, we studied prospectively 199 consecutive patients admitted to the coronary care unit. Values of MBCK and cTnI mass were determined in all samples. Of the 188 patients admitted with a suspicion of acute myocardial ischemia, 89 were diagnosed as having an acute myocardial infarction on the basis of the patterns of MBCK values. Eighty-six of these patients also had increased cTnI (concordance, 96.6%); three did not. Of the patients diagnosed as without infarction, five with unstable angina and symptoms in the day(s) prior to admission had increased cTnI, for a cTnI specificity of 94.9%. Receiver operating characteristic curve analysis indicated that cTnI and MBCK had statistically indistinguishable diagnostic accuracies for the detection of acute myocardial infarction.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
C Hansen ◽  
C Bang ◽  
K G Lauridsen ◽  
C A Frederiksen ◽  
M Schmidt ◽  
...  

Abstract Introduction According to ESC guidelines, an acute myocardial infarction (MI) can be excluded without serial troponin measurements in patients presenting with a single high-sensitive troponin below the 99th percentile and chest pain starting >6 hours prior to admission. However, it is unclear if single-testing of high-sensitive troponin can rule-out MI in early presenters. Purpose To investigate the diagnostic performance of a single value of high-sensitive cardiac troponin I (hs-cTnI) at presentation for ruling-out MI in patients presenting with chest pain to the Emergency Department irrespective of chest pain onset. Methods We conducted a substudy of preliminary data from the RACING-MI trial. We included patients presenting with chest pain suggestive of MI to the Emergency Department of a Regional Hospital. We used the Siemens hs-cTnI (Siemens Healthcare, TNIH, Limit of detection: 2.21 ng/L) and a diagnostic cut-off value <3 ng/L to rule-out MI at presentation. Two physicians independently adjudicated the final diagnosis based on all clinical information. Patients were stratified based on time from chest pain onset to hospital admission as very early (0–3 hours), early (3–6 hours) and late presenters (>6 hours). Results We included 989 patients with available hs-cTnI results at admission. MI was confirmed in 82 (8.3%) patients. Using hs-cTnI <3 ng/L as diagnostic cut-off value at presentation, 302 (30.5%) patients without MI were classified as rule-out. Overall, the negative predictive value (NPV) for MI was 100% (95% CI 98.7–100). Based on chest pain onset, 33.8% of patients were classified as very early, 12.8% as early, and 42.7% as late presenters, with 10.7% patients with unreported/unknown onset. NPV was 100% (95% CI 96.5–100) for very early, 100% (95% CI 88.3–100) for early and 100% (95% CI 97.3–100) for late presenters. Conclusions Using a single hs-cTnI value <3ng/L as diagnostic cut-off to rule-out MI seems to be safe and to allow rapid rule-out of MI in patients presenting with chest pain to the emergency department, even in very early presenters. ClinicalTrials.gov Identifier: NCT03634384. Acknowledgement/Funding Randers Regional Hospital, A.P Møller Foundation, Boserup Foundation, Korning Foundation, Højmosegård Grant, Siemens Healthcare (TNIH assays), etc.


1999 ◽  
Vol 45 (2) ◽  
pp. 206-212 ◽  
Author(s):  
Fred S Apple ◽  
Andrew J Maturen ◽  
Richard E Mullins ◽  
Pennell C Painter ◽  
Melissa S Pessin-Minsley ◽  
...  

Abstract We evaluated the AxSYM troponin I (cTnI) immunoassay for assisting in the detection of acute myocardial infarction (AMI). At four sites, the total imprecision (CV) over 20 days was 6.3–10.2%. The minimum detectable concentration was 0.14 ± 0.05 μg/L. Comparison of cTnI measurements between the AxSYM and Stratus (n = 406) over the dynamic range of the AxSYM assay demonstrated good correlation, r = 0.881, with a proportional bias: AxSYM cTnI = 3.50(Stratus cTnI) − 1.10. The confidence intervals (95%) for the slope and intercept were 3.39–3.64 and −1.32 to −0.95, respectively. The expected cTnI concentration in healthy individuals was ≤0.5 μg/L, whereas the ROC curve-determined cutoff for AMI was 2.0 μg/L. This gave a diagnostic sensitivity of 91.8% and specificity of 92.4% when tested in serial samples collected within 24 h of admission in 633 patients presenting with chest pain, of which 122 had an AMI. The concordances of the AxSYM cTnI with the Stratus cTnI, OPUS cTnI, and Access cTnI were 95.3%, 95.1%, and 94.3%, respectively, from patients with suspected AMI. The AxSYM cTnI demonstrated excellent clinical specificity, ≥96%, in skeletal muscle injury, chronic renal disease, and same-day noncardiac surgery patients.


2009 ◽  
Vol 55 (8) ◽  
pp. 1530-1538 ◽  
Author(s):  
Pierre N Floriano ◽  
Nicolaos Christodoulides ◽  
Craig S Miller ◽  
Jeffrey L Ebersole ◽  
John Spertus ◽  
...  

Abstract Background: For adults with chest pain, the electrocardiogram (ECG) and measures of serum biomarkers are used to screen and diagnose myocardial necrosis. These measurements require time that can delay therapy and affect prognosis. Our objective was to investigate the feasibility and utility of saliva as an alternative diagnostic fluid for identifying biomarkers of acute myocardial infarction (AMI). Methods: We used Luminex and lab-on-a-chip methods to assay 21 proteins in serum and unstimulated whole saliva procured from 41 AMI patients within 48 h of chest pain onset and from 43 apparently healthy controls. Data were analyzed by use of logistic regression and area under curve (AUC) for ROC analysis to evaluate the diagnostic utility of each biomarker, or combinations of biomarkers, in screening for AMI. Results: Both established and novel cardiac biomarkers demonstrated significant differences in concentrations between patients with AMI and controls without AMI. The saliva-based biomarker panel of C-reactive protein, myoglobin, and myeloperoxidase exhibited significant diagnostic capability (AUC = 0.85, P &lt; 0.0001) and in conjunction with ECG yielded strong screening capacity for AMI (AUC = 0.96) comparable to that of the panel (brain natriuretic peptide, troponin-I, creatine kinase-MB, myoglobin; AUC = 0.98) and far exceeded the screening capacity of ECG alone (AUC approximately 0.6). En route to translating these findings to clinical practice, we adapted these unstimulated whole saliva tests to a novel lab-on-a-chip platform for proof-of-principle screens for AMI. Conclusions: Complementary to ECG, saliva-based tests within lab-on-a-chip systems may provide a convenient and rapid screening method for cardiac events in prehospital stages for AMI patients.


2018 ◽  
Vol 16 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Bijaya Mishra ◽  
Sunil Pandey ◽  
Surya Raj Niraula ◽  
Bijendra Kumar Rai ◽  
Prahlad Karki ◽  
...  

Background: The diagnosis of acute coronary syndrome remains challenging, as cardiac troponins and creatine kinase-MB do not detect myocardial ischemia. Ischemia modified albumin is biomarker positive within 6-10 minutes following ischemic onset, where oxygen free radicals leads to reduction in binding capacity of human serum albumin to transitional metal-cobalt. The objective of this study was to compare ischemia modified albumin between acute coronary syndrome patients and healthy controls, and evaluate diagnostic performance of ischemia modified albumin compared to cardiac troponins, creatine kinase-MB and electrocardiogram in acute coronary syndrome patients.Methods: Fifty ACS patients and 50 healthy controls were enrolled in this cross-sectional study. Ischemia modified albumin was measured after addition of known amount of cobalt to human serum albumin, followed by spectrophotometric determination of unbound cobalt fraction at 470 nm using dithiothreitol as coloring agent. Independent student t-test and One-way ANOVA to compare differences of mean between groups; diagnostic sensitivity and specificity of ischemia modified albumin was determined by receiver operating characteristic curve; McNemar-test was used to assess diagnostic performance of entire test parameters, when used alone and in combinations.Results: Ischemia modified albumin was significantly higher in acute coronary syndrome patients compared to controls (0.823±0.191 vs 0.410±0.081)(p<0.001). Receiver operating characteristic curve derived optimal cutoff of 0.475 Absorbance unit had sensitivity and specificity of 92% and 82% respectively (area under curve- 0.96). However, no significant differences in mean ischemia modified albumin values between three categories of acute coronary syndrome were seen. Sensitivity of ischemia modified albumin assay (92%) was significantly higher compared to electrocardiogram (72%), cardiac troponin I (18%), and creatine kinase-MB(42%).Conclusions: Ischemia modified albumin is elevated in acute coronary syndrome patients with better diagnostic performance compared to electrocardiogram, cardiac troponin I, and creatine kinase-MB for early diagnosis, however, with limited ability to discriminate between ST-elevation myocardial infarction, non-ST-elevation myocardial infarction and unstable angina.


2021 ◽  
Author(s):  
Xiao Tong ◽  
Xin Yi Zhao ◽  
Li Jin Zhou ◽  
Miao Li ◽  
Jian Bin Han ◽  
...  

Abstract Background This study aimed to provide an early potential diagnosis of acute myocardial infarction (AMI) and determine its correlation with ferroptosis, immune checkpoints, and N6-methyladenosine (m6A). Methods We downloaded microarray data from NCBI (GSE61144, GSE60993, and GSE42148) and identified differentially expressed genes (DEGs) in samples from healthy subjects and patients with AMI. We also performed systematic gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses and used STRING to predict the interactions between proteins. Then we proceeded with the identification of the first ten DEGs by plotting the receiver operating characteristic curve using the multi-scale curvature classification algorithm, and verification of their diagnostic significance. Next, we investigated the relationship between these target genes and immune checkpoints, ferroptosis, and m6A. Results Through screening, we identified 253 DEGs, including 181 downregulated and 72 upregulated genes. According to GO, KEGG, and key gene screening results, GZMB, GZMA, PRF1, KLRB1, CD2, KLRD1, IL2RB, NKG7, GZMK, and CCL5 could be used for early prediction of AMI. Moreover, we found that AMI was associated with ferroptosis, immune checkpoints, and m6A. Conclusion GZMB, GZMA, PRF1, KLRB1, CD2, KLRD1, IL2RB, NKG7, GZMK, and CCL5 are effective markers for the diagnosis of AMI, which can provide new prospects for future studies on the pathogenesis of AMI.


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