AlphaLISA-Based Immunoassay for Detection of Troponin T in Serum of Patients with Acute Myocardial Infarction.

Survival and prognosis of patients with acute myocardial infarction (AMI) are highly dependent on rapid and accurate diagnosis of myocardial damage. Troponin T is the primary diagnostic biomarker and is widely used in clinical practice. Amplified luminescent proximity homogeneous assay (AlphaLISA) may provide a solution to rapidly detect a small amount of analyte through molecular interactions between special luminescent donor beads and acceptor bead. Here, a double-antibody sandwich assay was introduced into AlphaLISA for rapid detection for early diagnosis of AMI and disease staging evaluation. The performance of the assay was evaluated. The study found that the cTnT assay has a linear range of 48.66 to 20,000 ng/L with a limit of detection of 48.66 ng/L. In addition, the assay showed no cross-reactivity with other classic biomarkers of myocardial infarction and was highly reproducible with intra- and inter-batch coefficients of variation of less than 10%, notably, only 3 min was taken, which is particularly suitable for clinical diagnosis. These results suggest that our method can be conveniently applied in the clinic to determine the severity of the patient's condition.

Early changes in cardiac troponin T and NT-proBNP levels in neonates receiving ECMO support: a single-center experience.

OBJECTIVE: This study aimed to examine the changes in absolute value and decline rate of early serum cardiac troponin T (cTnT) and N-terminal pro b-type natriuretic peptide (NT-proBNP) in neonates who received veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO) support therapy within the first week of life. METHODS: We retrospectively collected clinical data and laboratory test results of 18 neonates who underwent V-A ECMO support within one week of birth, from July 2021 to June 2023, using the electronic medical record system. These patients were categorized into survival and death groups. Comparative analyses of the absolute values and decline rates of cTnT and NT-proBNP were made between the groups at baseline, and at 24, 48, and 72 h post-ECMO initiation. RESULTS: Out of the 18 neonates, 12 survived (survival rate: 66.7%), while 6 succumbed. The survival group exhibited significantly lower absolute values of cTnT and NT-proBNP than the death group, and their decline rates were significantly higher. Notably, all neonates without an early decline in cTnT and NT-proBNP levels were in the death group. CONCLUSION: The early changes in the absolute value and decline rate of serum cTnT and NT-proBNP in neonates undergoing V-A ECMO may serve as predictors of their prognosis.

Heart Failure: Is There an Ideal Biomarker?

An always-rising prevalence of heart failure (HF), formerly classified as an emerging epidemic in 1997 and still representing a serious problem of public health, imposes on us to examine more in-depth the pathophysiological mechanisms it is based on. Over the last few years, several biomarkers have been chosen and used in the management of patients affected by HF. The research about biomarkers has broadened our knowledge by identifying some underlying pathophysiological mechanisms occurring in patients with both acute and chronic HF. This review aims to provide an overview of the role of biomarkers previously identified as responsible for the pathophysiological mechanisms subtending the disease and other emerging ones to conduct the treatment and identify possible prognostic implications that may allow the optimization of the therapy and/or influence a closer follow-up. Taking the high prevalence of HF-associated comorbidities into account, an integrated approach using various biomarkers has shown promising results in predicting mortality, a preferable risk stratification, and the decrease of rehospitalizations, reducing health care costs as well.

Higher troponin T serum concentrations in hospital patients without diagnosed cardiac diseases compared to a population-based cohort.

OBJECTIVES: Upper reference limits of high-sensitivity cardiac troponin T (hs-cTnT) are derived from healthy, population-based cohorts, and are frequently exceeded in hospitalized patients. In this study we aim to systematically examine the differences between in-hospital patients with no diagnosed cardiac diseases and a population-based cohort. METHODS: Retrospective analyses were performed in two independent cohorts. We included 5,652 participants of the prospective population-based LIFE cohort as well as 9,300 patients having been treated at our hospital between 2014 and 2021. In both cohorts, subjects with diagnosed or suspected cardiac diseases were excluded. We used Spearman's rank correlation for correlation analyses of hs-cTnT serum concentrations and age. Sex- and age-adjusted 99th percentiles for hs-cTnT in subjects with preserved renal function were obtained in both cohorts. RESULTS: In both cohorts, hs-cTnT serum concentrations positively correlated with age. Male sex was associated with higher hs-cTnT serum concentrations. Persons treated in hospital showed significantly higher hs-cTnT concentrations in females and males aged above 50. While in the population-based cohort only 99th percentile hs-cTnT results of females aged above 70 and males aged above 60 years exceeded the assay's upper reference limit, the 99th percentiles of in-hospital females over 40 years and males of all age groups exceeded this threshold. CONCLUSIONS: Besides age and sex, hospitalization per se is correlated with higher serum concentrations of hs-cTnT in most age groups. Our results indicate, that unconditionally applying current hs-cTnT cut-offs to inpatients might overestimate myocardial infarction and potentially lead to overdiagnosis.

Postmortem biochemical analysis of soluble ST2 in the pericardial fluid of patients with sudden cardiac death caused by ischemic heart disease: a pilot study.

Soluble growth stimulation expressed gene 2 protein (sST2) is a myocardial protein induced by biomechanical stress. sST2 is widely present in the serum of patients with heart failure and is recommended as an important indicator to predict adverse outcomes in these patients. However, no postmortem biochemical analysis of sST2 in forensic practice has been reported. The present pilot study aimed to investigate the expression of sST2 in the pericardial fluid of patients with sudden cardiac death (SCD) caused by ischemic heart disease (IHD). In addition, to explore the relationship of sST2 with CK-MB, cTnT, and NT-proBNP, which have been proven to be auxiliary biomarkers for the diagnosis of SCD, we analyzed CK-MB, cTnT, NT-proBNP, and sST2 levels in twenty-one pericardial fluid samples from the Center of Forensic Investigation, China Medical University, with a Roche cobas e 411 electrochemiluminescence automatic immunoassay system and ST2/IL-33R Valukine™ enzyme-linked immunosorbent assay kit. The levels of sST2 in the pericardial fluid of patients with SCD caused by IHD were significantly increased (P < 0.01) and positively correlated with CK-MB and NT-proBNP (P < 0.0001). Receiver operating characteristic curve analysis indicated that the combined measurement of sST2 and NT-proBNP has a higher diagnostic value for SCD caused by IHD than the measurement of either indicator alone. This study preliminarily demonstrated that sST2 in the pericardial fluid was significantly increased in patients with SCD caused by IHD and might be used as a novel auxiliary biomarker for postmortem diagnosis of SCD in forensic practice.

A comparison of modelled serum cTnT and cTnI kinetics after 60 min swimming.

Post-exercise elevations of cardiac troponin T (cTnT) and I (cTnI) are often used in isolation but interpreted interchangeably. Research suggests, however, that post-exercise cTn kinetic might differ with each isoform. In this cross-sectional observational study, we collected blood samples before, immediately after (5 minutes), and at 1-, 3-, 6-, 12-, and 24-hour post-exercise in a mixed cohort of 56 participants after a distance-trial of 60 min continuous swimming (age range from 14 to 22, 57.1% female). Cardiac troponin kinetics were modelled using Bayesian mixed-effects models to estimate time to peak (TTP) and peak concentration (PC) for each isoform, while controlling for participants sex, tanner stage and average relative heart rate during the test. Exercise induced an elevation of cTnT and cTnI in 93% and 75% of the participants, respectively. Cardiac troponin T peaked earlier, at 2.9 h (CI: 2.6 - 3.2 h) post-exercise, whereas cTnI peaked later, at 4.5 h (CI: 4.2 - 4.9 h). Peak concentrations for cTnT and cTnI were 2.5 ng/L, CI: 0 - 11.2 ng/L and 2.16 ng/L, CI: 0 - 22.7 ng/L, respectively. Additionally, we did not observe a systematic effect of sex and maturational status mediating cTn responses.

Evaluation of the 0 h/1 h high-sensitivity cardiac troponin T algorithm in diagnosis of non-ST-segment elevation myocardial infarction (NSTEMI) in Han population.

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.

Establishment of the reference interval for high-sensitivity cardiac troponin T in healthy children of Chongqing Nan'an district.

OBJECTIVE: To detect the concentration of high-sensitivity cardiac troponin T (hs-cTnT) in healthy children aged 0-14 years by electrochemiluminescence immunoassay (ECLIA), so as to explore the differences in different ages and genders. The aim of this study is to establish the reference interval for hs-cTnT in healthy children aged 0-14 years. METHODS: After screening, 3463 healthy children, including 1924 boys and 1539 girls, were selected from 4617 children aged 0-14 years. They were divided into nine groups: one day (umbilical cord blood; 'UCB'), one day (venous blood; 'VB'), 2-28 days, 29 days-<3 months, 3-<6 months, 6 months-<1 year old, 1-< 3 years old, 3-< 6 years old and 6-14 years old. A nonparametric test was used to detect the hs-cTnT concentration. The upper limit of the reference interval is the mean of the 99th percentile after bootstrap sampling. RESULTS: Hs-cTnT levels conformed to a non-Gaussian distribution. There was no significant difference in the concentration of hs-cTnT between boys and girls in the general data, but there were differences between boys and girls in the 3-<6 years old and 6-14 years old age groups. Except for UCB and 2-28 days, the concentration of hs-cTnT was significantly different in other age groups. The level of hs-cTnT in neonatal serum (2-28 days) was the highest. In other groups, it decreased gradually with age and dropped to the reference range of adults (0-14ng/L) at one-year old. The upper limit of reference interval of hs-cTnT concentration in each group was, respectively, 60.8, 78.8, 96.6, 58.6, 34.2, 16.2, 11.4, 8.0 (7.8 female), and 7.9 (7.3 female) ng/L. CONCLUSIONS: Referring to WS/T 402-2012 establishment of reference intervals for clinical laboratory testing projects and CLSI (Clinical and Laboratory Standards Institute) C28-A3 documents and the joint expert consensus of ESC (European Society of Cardiology) and ACC (American College of Cardiology) in 2007, we established the reference interval of hs-cTnT concentration in children aged 0-14 years in Chongqing Nan'an district of China which can provide certain reference value for clinical diagnosis and treatment of myocarditis and myocardial (micro) injury in children.

Biomarkers assessment in patients with Chagas disease and systemic arterial hypertension.

Chagas disease (ChD) and systemic arterial hypertension (SAH) are two severe comorbidities that lead to mortality and a reduction in people's quality of life, with an impact on public health. The aim of this study was to quantify the biomarkers of cardiac injury in patients with ChD and SAH. Eighty patients were divided into four groups: 20 hypertensive patients, 20 ChD-hypertensive patients, 20 ChD patients, and 20 normotensive volunteers; all of them came from outpatient's public health services. Among the evaluated markers for cardiac lesions (creatine kinase, creatine kinase-MB isoform, myoglobin, high-sensitive cardiac troponin T[hs-cTnT], B-type natriuretic peptide [BNP], and C-reactive protein), hs-cTnT and BNP were the most appropriate. Importantly, our results showed that the cut off point for hs-cTnT could be < 0.007 ng/mL, which could lead to the early detection of myocardial lesions. The BNP and hs-cTnT levels were high only in the ChD and ChD-hypertensive patient groups, suggesting that Chagas' disease may play an important role in the increase of these biomarkers. ChD patients, hypertensive or not, with cardiac or cardiodigestive involvement presented significantly higher values of hs-cTnT (p < 0.001) and BNP (p = 0.001) than ChD patients with indeterminate and digestive forms, which strengthens the validation of these markers for the follow-up of clinical cardiac form of ChD. This study suggests that the BNP and hs-cTnT can be used as possible indirect biomarkers of cardiac damage. In addition, the reference values of these biomarkers in Chagas and hypertensive cardiomyopathies should be better understood with further studies.

Associations of Cardiac, Kidney, and Diabetes Biomarkers With Peripheral Neuropathy among Older Adults in the Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: The aim of this study was to assess the association of high-sensitivity cardiac troponin (hs-cTnT) and other cardiac, kidney, hyperglycemia, and inflammatory biomarkers with peripheral neuropathy (PN) in a community-based population. METHODS: We conducted a cross-sectional analysis of 3056 black and white participants in the Atherosclerosis Risk in Communities (ARIC) study who underwent standardized monofilament PN testing and had measures of cardiac function (hs-cTnT, N-terminal pro-B-type natriuretic peptide [NT-proBNP], and growth differentiation factor 15 [GDF15]), kidney function (serum creatinine, cystatin C, ß-2 microglobulin, urine albumin-to-creatinine ratio), hyperglycemia (fasting glucose, hemoglobin A1c [Hb A1c], fructosamine, glycated albumin, 1,5-anhydroglucitol), and inflammation (C-reactive protein) assessed at visit 6 (2016-2017; age 71-94 years). We used logistic regression to assess the associations of these biomarkers (modeled in diabetes-specific tertiles) with PN in older adults with and without diabetes after adjusting for traditional risk factors. RESULTS: In total, 33.5% of participants had PN (37.3% with diabetes and 31.9% without diabetes). There was an independent association of hs-cTnT with PN regardless of diabetes status (diabetes T3 vs. T1: odds ratio [OR], 2.15 [95% CI, 1.44-3.22]; no diabetes: OR, 2.31 [95%CI, 1.76-3.03]; P = 0.72 for interaction). Among participants without diabetes, there were also significant associations of NT-proBNP (OR, 1.40 [95% CI, 1.08-1.81]) and urine albumin-to-creatinine ratio (OR, 1.55 [95% CI, 1.22-1.97]) with PN. Associations of hyperglycemia biomarkers including Hb A1c (OR, 1.76 [95% CI, 1.22-2.54]), fructosamine (OR, 1.71 [95% CI, 1.19-2.46]), and glycated albumin (OR, 1.45 [95% CI, 1.03-2.03]) with PN were significant only among participants with diabetes. CONCLUSIONS: Overall, hs-cTnT appears to be a global marker of end organ damage, including PN. Laboratory biomarkers may be able to help us identify those individuals with PN.

Cancer Survivorship and Subclinical Myocardial Damage.

Cancer survivors might have an excess risk of cardiovascular disease (CVD) resulting from toxicities of cancer therapies and a high burden of CVD risk factors. We sought to evaluate the association of cancer survivorship with subclinical myocardial damage, as assessed by elevated high-sensitivity cardiac troponin T (hs-cTnT) test results. We included 3,512 participants of the Atherosclerosis Risk in Communities Study who attended visit 5 (2011-2013) and were free of CVD (coronary heart disease, heart failure, or stroke). We used multivariate logistic regression to evaluate the cross-sectional associations of survivorship from any, non-sex-related, and sex-related cancers (e.g., breast, prostate) with elevated hs-cTnT (≥14 ng/L). Of 3,512 participants (mean age, 76 years; 62% women; 21% black), 19% were cancer survivors. Cancer survivors had significantly higher odds of elevated hs-cTnT (OR = 1.26, 95% CI: 1.03, 1.53). Results were similar for survivors of non-sex-related and colorectal cancers, but there was no association between survivorship from breast and prostate cancers and elevated hs-cTnT. Results were similar after additional adjustments for CVD risk factors. Survivors of some cancers might be more likely to have elevated hs-cTnT than persons without prior cancer. The excess burden of subclinical myocardial damage in this population might not be fully explained by traditional CVD risk factors.

Cardiac Troponin T in Healthy Full-Term Infants.

In this prospective cohort study of healthy full-term infants, we hypothesized that high-sensitivity cardiac troponin T (hs-cTnT) would be elevated in cord blood, compared with adult reference values, and that it would further increase over the first days of age. Cardiac troponin T has been shown to be significantly increased in healthy full-term newborns compared with adult reference values, but there is no established reference range. Most studies of cTnT in newborns have been performed before the introduction of high-sensitivity cTnT (hs-cTnT) assay. We conducted a study including 158 full-term newborns, at Stockholm South General Hospital. High-sensitivity cTnT was analyzed in umbilical cord blood and at 2-5 days of age. Median hs-cTnT (interquartile range) in cord blood was 34(26-44) ng/L; 99th percentile 88 ng/L. Median hs-cTnT at 2-5 days of age was 92(54-158) ng/L; 99th percentile 664 ng/L. We conclude that hs-cTnT is elevated in cord blood in healthy, full-term newborn infants compared with adult reference values, and that it increases significantly during the first days of life. Our findings further underline the need of caution when using hs-cTnT as a measurement of cardiac impact in newborns.

Cardiac Biomarker Release After Exercise in Healthy Children and Adolescents: A Systematic Review and Meta-Analysis.

PURPOSE: The authors evaluated the impact of acute exercise and 24-hour recovery on serum concentration of cardiac troponins T and I (cTnT and cTnI) and N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) in healthy children and adolescents. The authors also determined the proportion of participants exceeding the upper reference limits and acute myocardial infarction cutoff for each assay. METHOD: Web of Science, SPORTDiscus, MEDLINE, ScienceDirect, and Scopus databases were systematically searched up to November 2017. Studies were screened and quality-assessed; the data was systematically extracted and analyzed. RESULTS: From 751 studies initially identified, 14 met the inclusion criteria for data extraction. All 3 biomarkers were increased significantly after exercise. A decrease from postexercise to 24 hours was noted in cTnT and cTnI, although this decrease was only statistically significant for cTnT. The upper reference limit was exceeded by 76% of participants for cTnT, a 51% for cTnI, and a 13% for NT-proBNP. Furthermore, the cutoff value for acute myocardial infarction was exceeded by 39% for cTnT and a 11% for cTnI. Postexercise peak values of cTnT were associated with duration and intensity (Q(3) = 28.3, P < .001) while NT-proBNP peak values were associated with duration (Q(2) = 11.9, P = .003). CONCLUSION: Exercise results in the appearance of elevated levels of cTnT, cTnI, and NT-proBNP in children and adolescents. Postexercise elevations of cTnT and NT-proBNP are associated with exercise duration and intensity.

The clinical prognostic significance of hs-cTnT elevation in patients with acute ischemic stroke.

BACKGROUND: Cardiac autonomic dysfunction caused by ischemic stroke might lead to an adverse outcome. Elevated high sensitivity cardiac troponin (hs-cTnT) is a marker of cardiac disease, it can elevate in acute stroke patients. The aim of the present study was to investigate association between serum hs-cTnT with prognosis among patients with acute ischemic stroke. METHODS: Five hundred and sixteen patients (mean age 66.19 ± 10.11) with acute ischemic stroke underwent a comprehensive clinical investigation and serum hs-cTnT activity test. All patients were followed up for 3 months. The prognosis was death or major disability (modified Rankin Scale score ≥ 3) at 3 months after acute ischemic stroke. RESULTS: 22.87% (118/516) of patients had serum hs-cTnT elevation (≥14 ng/l). Compared with normal hs-TnT group, the incidence of insular stroke (adjusted odds ratio, 2.84; 95% confidence interval, 1.48-4.17; P = 0.001) were more likely in patients with hs-cTnT elevation. In fully adjusted models, there was an association between serum hs-cTnT elevation and death (adjusted odds ratio, 3.14; 95% confidence interval, 1.16-8.49; P = 0.02) and major disability(adjusted odds ratio, 2.07; 95% confidence interval, 1.04-4.51; P = 0.04), and composite outcome(adjusted odds ratio,2.22;95% confidence interval,1.10-4.48; P = 0.03). CONCLUSIONS: Higher levels of serum hs-cTnT were independently associated with increased risk of death or major disability after stroke onset, suggesting that serum hs-cTnT may have prognostic value in poor outcomes of ischemic stroke.

Determination of age- and sex-specific 99th percentiles for high-sensitive troponin T from patients: an analytical imprecision- and partitioning-based approach.

BACKGROUND: Detection of acute myocardial infarction (AMI) is mainly based on a rise of cardiac troponin with at least one value above the 99th percentile upper reference limit (99th URL). However, circulating high-sensitive cardiac troponin T (hs-cTnT) concentrations depend on age, sex and renal function. Using an analytical imprecision-based approach, we aimed to determine age- and sex-specific hs-cTnT 99th URLs for patients without chronic kidney disease (CKD). METHODS: A 3.8-year retrospective analysis of a hospital laboratory database allowed the selection of adult patients with concomitant plasma hs-cTnT (<300 ng/L) and creatinine concentrations, both assayed twice within 72 h with at least 3 h between measurements. Absence of AMI was assumed when the variation between serial hs-cTnT values was below the adjusted-analytical change limit calculated according to the inverse polynomial regression of analytical imprecision. Specific URLs were determined using Clinical and Laboratory Standards Institute (CLSI) methods, and partitioning was tested using the proportion method, after adjustment for unequal prevalences. RESULTS: After outlier removal (men: 8.7%; women: 6.6%), 1414 men and 1082 women with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 were assumed as non-AMI. Partitioning into age groups of 18-50, 51-70 and 71-98 years, the hs-cTnT 99th URLs adjusted on French prevalence were 18, 33, 66 and 16, 30, 84 ng/L for men and women, respectively. Age-partitioning was clearly required. However, sex-partitioning was not justified for subjects aged 18-50 and 51-70 years for whom a common hs-cTnT 99th URLs of about 17 and 31 ng/L could be used. CONCLUSIONS: Based on a laboratory approach, this study supports the need for age-specific hs-cTnT 99th URLs.

Diagnostic Approach to Cardiac Involvement in Idiopathic Inflammatory Myopathies.

Cardiac involvement in idiopathic inflammatory myopathies (IIMs) attracts more attention than it ever did because of its morbidity and impact on worse prognosis, although the accurate information needs further epidemiological studies. Early identification and intervention for the diseased heart may help improve the clinical outcomes of IIMs with cardiac involvement. Cardiac troponin assays, allowing for sensitive detection of minor myocardium injury, may provide a new way for early detection for heart involvement in IIMs. While elevated cardiac troponin I (cTnI) specifically indicates cardiomyocyte injury, the elevation of cardiac troponin T (cTnT) levels may not only derive from damaged heart but also diseased adult skeletal muscles in which cTnT could re-express in patients with IIMs. cTnI is the biomarker of choice for diagnosis of cardiac involvement and may also be a prognostic factor in IIMs. Meanwhile, electrocardiography (ECG), cardiac imaging (e.g., echocardiography, cardiac magnetic resonance) and histopathological techniques (e.g., endomyocardial biopsy) take on different degrees of importance for the diagnosis of cardiac involvement. We propose a diagnostic strategy combining the routine use of cTnI assay with other techniques (routine ECG and echocardiography, cardiac magnetic resonance, and or endomyocardial biopsy in necessity) and clinical investigation for early detection of heart involvement in IIMs. Future researches are required to validate the algorithm for performance.

The Relationship Between Serum Zinc Levels, Cardiac Markers and the Risk of Acute Myocardial Infarction by Zinc Quartiles.

BACKGROUND: Zinc is one of the most important microelements in the body and zinc homeostasis plays a critical role in maintaining cellular structure and function. Zinc dyshomeostasis can lead to many diseases, such as cardiovascular disease. Our aim was to investigate whether there is a relationship between zinc and cardiac markers, and the risk of acute myocardial infarction (AMI) by zinc quartiles. METHODS: We enrolled a total of 529 patients and measured their serum zinc levels and cardiac markers. We performed further studies after dividing subjects into four groups according to their concentrations of zinc by quartile to clarify the relationship between zinc levels and risk of increased acute myocardial infarction prevalence rate. RESULTS: We observed that there was a significant inverse linear relationship between zinc and Lg(creatine kinase) (p=0.011), Lg(creatine kinase-MB) (p=0.002) and Lg(cardiac troponin T) (p=0.045). In addition, the acute myocardial infarction prevalence rates were 28.8%, 24.8%, 20.5%, and 18.2% by patients with zinc quartiles, respectively. Multivariate logistic regression analysis showed that the odds ratio between the lowest and highest zinc quartile groups was 1.92 (1.019-3.604) (p<0.05). CONCLUSIONS: The present study revealed a relationship between serum zinc levels in that zinc levels were significantly inversely correlated with serum creatine kinase (CK), creatine kinase-MB (CKMB) and cardiac troponin T (cTnT) levels. Furthermore, we found that the prevalence rate of acute myocardial infarction decreased with increasing zinc quartiles.

The prognostic significance of serum troponin T levels in Crimean-Congo hemorrhagic fever patients.

Crimean-Congo Hemorrhagic Fever (CCHF) is a disease transmitted by the Crimean-Congo hemorrhagic fever virus (CCHFV), characterized by severe fever and hemorrhage and with a reported fatality level of 3-30%. Cerebral hemorrhage, gastrointestinal hemorrhage, severe anemia, shock, myocardial infarction, pulmonary edema, and pleural effusion may be seen as causes of death. Cardiac troponin T (cTn-T) is a biochemical marker with high sensitivity and specificity in myocardial injury. The purpose of this study was to determine the prognostic significance of serum troponin T levels in CCHF patients. Patients hospitalized with a diagnosis of CCHF and whose serum cTn-T was investigated were examined retrospectively. Patients were divided into two groups on the basis of presence or absence of hemorrhage. Data were subjected to statistical analysis. One hundred thirty-five CCHF patients and 72 control subjects were included. Hemorrhage was present in 48 (35.6%) patients. Mean serum cTn-T level was 17.3 ± 28.0 ng/L in the patients with hemorrhage, 9.98 ± 5.97 ng/L in the non-hemorrhage patients (P = 0.001) and 6.6P = 2.6 ng/L in the control samples (P < 0.001). At a cTn-T level cut-off point of 9 ng/L, area under the ROC curve was 0.797 (95%CI: 0.730-0.854), sensitivity 83.0%, specificity 87.5%, PPD 95.7%, and NPV 60.3%. At logistic regression analysis, a rise in cTn-T level above 14 ng/L increased the probability of hemorrhage in CCHF patients approximately threefold. An increased troponin T level may be a prognostic risk factor for hemorrhage in CCHF patients. This marker should therefore be borne in mind in determining treatment strategy in these patients. J. Med. Virol. 89:408-412, 2017. © 2015 Wiley Periodicals, Inc.

Point of care assessment of cardiac troponin T level in CKD patients with chest symptom.

We challenged to identify the cutoff value of cTnT in chronic kidney disease (CKD) patients by point of care assessment way. A single center, prospective cross-sectional study was planned and performed. 201 consecutive patients who were visited emergency room for chest symptoms were enrolled in this study. All patients were performed routine practice for differential diagnosis of chest symptom by cardiologist. Simultaneously, semiquantitative measurement of cTnT was performed using same blood sampling on the blind condition to cardiologists for this study. Study patients were divided into four groups according to the estimated glomerular filtration rate (eGFR), CKD1-2, CKD3, CKD4-5, and CKD5D. Usefulness of semiquantitative measurement for diagnosing ACEs was investigated in each group. 77 (38%) of total patient was diagnosed as acute coronary events (ACEs). About 50% of patients were showing cTnT level less than 0.03 ng/mL. The cTnT level over 0.1 ng/mL was found in 30% of total subjects. Mean quantitative value of cTnT was 0.29 ± 0.57 ng/mL in total subjects. Estimated cutoff value in CKD3 patients was 0.088 ng/mL with a sensitivity of 59.3% and specificity of 80.0%. Interestingly, the cutoff values of CKD1-2, CKD4-5, and CKD5D were 0.047, 0.18, and 0.27 respectively, which are half, two times, and three times of CKD3 cutoff value 0.088. The specificities of four cutoff values in each CKD group were showing over 80%, which is higher than sensitivity, respectively. In CKD patients, semiquantitative, point of care assessment of cTnT could be a useful tool for screening for ACEs.

Effects of acute, intermittent exercise in hypoxic environments on the release of cardiac troponin.

The purpose of this study was to examine the effects of acute, intermittent exercise performed in hypoxic environments on the release of cardiac troponin (cTn). Ten well-trained, male marathon runners (22.1 ± 2.6 years, 64.0 ± 4.9 kg and 177.3 ± 3.9 cm) completed three intermittent exercise protocols under normoxic (trial N) and hypoxic (trial AH and RH) conditions. In trial N, the fraction of inspiration oxygen (FIO2 ) was 21.0% and exercise intensity was 90% and 50% normoxic velocity of VO2max (vVO2max). In trial AH, FIO2 was 14.4% (simulated altitude of 3000 m) and exercise intensity was 90% and 50% normoxic vVO2max. In trial RH, FIO2 was 14.4% and exercise intensity was 90% and 50% hypoxic vVO2max. High-sensitivity cardiac troponin T (hs-cTnT) and cardiac troponin I (cTnI) were measured pre- and 0, 2, 4, and 24 h post-exercise. Hs-cTnT was elevated in all three trials, peaking at 2 to 4 h and returning to the baseline 24 h post-exercise. CTnI increased in trial AH, peaking at 2 to 4 h and returning below the detection limit 24 h post-exercise. It is concluded that the stimulus of hypoxia did not in and of itself induce more cTn to be released, but exercise intensity could affect this response in hypoxic environments.