Cardiac troponins: are there any differences between T and I?

Age- and sex-specific upper reference limits for cardiac biomarkers in Chinese children and adolescents: a prospective study

Cardiac biomarkers are being increasingly applied in pediatric populations, including those with cardiogenic and non-cardiogenic myocardial injury disease. The upper reference limits of biomarkers are an important reference for disease diagnosis and health evaluation. However, the upper reference limits of pediatric cardiac biomarkers remains unknown. A total of 1,797 serum samples were collected prospectively from healthy respondents aged 0 to 18 years old. These samples were analyzed using Roche cobas e411 to determine the concentrations of hs-cTnT, CK-MB mass, and NT-proBNP. The upper reference limits and 90% confidence interval were calculated according to Clinical and Laboratory Standards Institute C28- A3 guidelines. The study successfully established the upper reference limits for hs-cTnT, CK-MB mass, and NT-proBNP in healthy children and adolescents aged 0 to 18. The hs-cTnT, CK-MB mass, and NT-proBNP levels were visibly higher in neonatal serum. With the increase in age, hs-cTnT, CK-MB mass, and NT-proBNP decline gradually. They decrease quickly in the first year after birth and decrease slowly after 1 year old. Gender differences were observed in the concentrations of hs-cTnT and CK-MB mass among healthy children and teenagers aged 10 to 18 and 13 to 18. Specifically, boys had relatively higher concentrations of hs-cTnT and CK-MB mass. However, no gender difference was found in NT-proBNP concentration. The concentrations of hs-cTnT, CK-MB mass, and NT-proBNP were simultaneously tested in healthy Chinese children for the first time. The specific upper reference limits of age and gender in pediatrics were established. The results provide comprehensive references for medical institutions specializing in children's healthcare, which are conducive to preliminary screening, diagnosis, and treatment of pediatric cardiovascular diseases.

Association of α-HBDH levels with the severity and recurrence after acute ischemic stroke

OBJECTIVE

α-HBDH serves as a biomarker of myocardial damage and is implicated in adverse outcomes across various critical illnesses. Our study aimed to assess the correlation between α-HBDH levels, and severity and recurrence of acute ischemic stroke (AIS).

METHODS

We enrolled patients with mild-to-moderate AIS within 72 h of onset. Based on the baseline score of the National Institutes of Health Stroke Scale (bNIHSS) at registration, patients were categorized into mild (bNIHSS ≤ 4 points) and moderate AIS groups (4 < bNIHSS ≤ 10 points). Subsequently, based on the normal upper limit of α-HBDH, patients were divided into low-level α-HBDH (≤ 180 U/L) and high-level α-HBDH (> 180 U/L) groups. Multivariate logistic regression analysis and Cox proportional hazard regression analysis were employed to evaluate the relationship between α-HBDH levels and bNIHSS scores as well as the risk of recurrent AIS within 90 days.

RESULTS

We observed a significant association between higher baseline levels of α-HBDH and increased bNIHSS scores, indicating a more severe AIS (odds ratio = 24.449; 95% confidence interval [CI], 8.749-68.324; p < 0.01). Additionally, the risk of recurrent AIS within 90 days was 4.666 times higher in the high-level α-HBDH group compared to the low-level group (hazard ratio = 4.666; 95% CI, 2.481-8.777; p < 0.01).

CONCLUSIONS

The baseline level of α-HBDH is significantly correlated with the severity of AIS and the risk of recurrent AIS within 90 days.

Association of cardio-renal biomarkers and mortality in the U.S.: a prospective cohort study

OBJECTIVE

Diabetes poses a significant threat to human health. There is a lack of large-scale cohort studies to explore the association between mortality risk and indicators beyond blood glucose monitoring in diabetic populations.

METHODS

Multivariable Cox proportional hazards regression models were performed to investigate the association of 13 blood biomarkers with mortality risk in the National Health and Nutrition Examination Survey (NHANES) and biomarker levels were log-transformed and correlated with mortality.

RESULTS

During a median follow-up of 7.42 years, 1783 diabetic patients were enrolled. Compared to traditional risk factors, the addition of hs-cTnT, hs-cTnI, NT-proBNP, creatinine, cystatin C, and β-2 microglobulin biomarkers increased the predictive ability for all-cause mortality by 56.4%, 29.5%, 38.1%, 18.8%, 35.7%, and 41.3%, respectively. However, the inclusion of blood glucose monitoring had no impact on the prediction of all-cause mortality. Compared with the 1st quartiles of creatinine and Cystatin C, the risk of diabetes mortality were higher in the highest quartiles (HR: 5.16, 95% CI: 1.87-14.22; HR: 10.06, 95% CI: 4.20-24.13).

CONCLUSIONS

In the diabetic population, elevated plasma levels of hs-cTnT, hs-cTnI, NT-proBNP, creatinine, cystatin C, and β-2 microglobulin serve as robust and straightforward predictors of long-term mortality compared to blood glucose levels and HbA1c values. Creatinine and cystatin C stand out as more precise markers for predicting diabetes mortality prior to blood glucose monitoring.

Cardiac Troponin Release after Exercise in Healthy Young Athletes: A Systematic Review

Cardiac troponin (cTn) is a recognized marker used to assess damage to the heart muscle. Actual research has indicated that the levels of cTn increase after doing exercise in individuals who are in good health, and this is believed to be a result of a normal cellular process rather than a pathological one. The main goal of this study was to investigate the evidence of a postexercise release of cTn in child and adolescent athletes (6-17.9 years old) of different ages, sex, and sports disciplines. The Web of Science, MEDLINE, and Scopus databases were used to conduct the research up to March 2023. Three hundred and twenty-eight records were identified from the databases, however, only twenty-three studies were included in the review after being screened and quality-assessed by two independent authors. The gender, age of the participants, maturational status, and training level of the participants, the timing of sample collection, the exercise modality, and the number of participants with values above the cut-off reference were the data analyzed. Males, older young people, and individual sports seemed to have higher levels of serum cTn after practice exercise. Different methodologies, analyzers, and cut-off reference values make it difficult to compare the data among studies.

Variability of cardiac troponin levels in normal subjects and in patients with cardiovascular diseases: analytical considerations and clinical relevance

In accordance with all the most recent international guidelines, the variation of circulating levels of cardiac troponins I and T, measured with high-sensitivity methods (hs-cTnI and hs-cTnT), should be used for the detection of acute myocardial injury. Recent experimental and clinical evidences have demonstrated that the evaluation of hs-cTnI and hs-cTnT variations is particularly relevant: a) for the differential diagnosis of Acute Coronary Syndromes (ACS) in patients admitted to the Emergency Department (ED); b) for the evaluation of cardiovascular risk in patients undergoing major cardiac or non-cardiac surgery, and in asymptomatic subjects of the general population aged >55 years and with co-morbidities; c) for the evaluation of cardiotoxicity caused by administration of some chemotherapy drugs in patients with malignant tumors. The aim of this document is to discuss the fundamental statistical and biological considerations on the intraindividual variability of hs-cTnI and hs-cTnT over time in the same individual. Firstly, it will be discussed in detail as the variations of circulating levels strictly depend not only on the analytical error of the method used but also on the intra-individual variability of the biomarker. Afterwards, the pathophysiological interpretation and the clinical relevance of the determination of the variability of the hs-cTnI and hs-cTnT values ​​ in patients with specific clinical conditions are discussed. Finally, the evaluation over time of the variation in circulating levels of hs-cTnI and hs-cTnT is proposed for a more accurate estimation of cardiovascular risk in asymptomatic subjects from the general population.

Inflammageing and Cardiovascular System: Focus on Cardiokines and Cardiac-Specific Biomarkers

The term "inflammageing" was introduced in 2000, with the aim of describing the chronic inflammatory state typical of elderly individuals, which is characterized by a combination of elevated levels of inflammatory biomarkers, a high burden of comorbidities, an elevated risk of disability, frailty, and premature death. Inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and rapid progression to heart failure. The great experimental and clinical evidence accumulated in recent years has clearly demonstrated that early detection and counteraction of inflammageing is a promising strategy not only to prevent cardiovascular disease, but also to slow down the progressive decline of health that occurs with ageing. It is conceivable that beneficial effects of counteracting inflammageing should be most effective if implemented in the early stages, when the compensatory capacity of the organism is not completely exhausted. Early interventions and treatments require early diagnosis using reliable and cost-effective biomarkers. Indeed, recent clinical studies have demonstrated that cardiac-specific biomarkers (i.e., cardiac natriuretic peptides and cardiac troponins) are able to identify, even in the general population, the individuals at highest risk of progression to heart failure. However, further clinical studies are needed to better understand the usefulness and cost/benefit ratio of cardiac-specific biomarkers as potential targets in preventive and therapeutic strategies for early detection and counteraction of inflammageing mechanisms and in this way slowing the progressive decline of health that occurs with ageing.

Diagnosis of acute myocardial infarction: highlighting cardiac troponins as vital biomarkers

The molecular marker, cardiac troponin (cTn) is a complex protein that is attached to tropomyosin on the actin filament. It is an essential biomolecule in terms of the calcium-mediated regulation of the contractile apparatus in myofibrils, the release of which is an indication of the dysfunction of cardiomyocytes and hence the initiation of ischemic phenomena in the heart tissue. Fast and accurate analysis of cTn may help the diagnosis and management of acute myocardial infarction (AMI), for which electrochemical biosensors and microfluidics devices can be of great benefit. This editorial aims to highlight the importance of cTn as vital biomarkers in AMI diagnosis.

Evaluation of the cardiovascular risk in patients undergoing major non-cardiac surgery: role of cardiac-specific biomarkers

Major adverse cardiovascular events are frequently observed in patients undergoing major non-cardiac surgery during the peri-operative period. At this time, the possibility to predict cardiovascular events remains limited, despite the introduction of several algorithms to calculate the risk of adverse events, mainly death and major adverse cardiovascular events (MACE) based on the clinical history, risk factors (sex, age, lipid profile, serum creatinine) and non-invasive cardiac exams (electrocardiogram, echocardiogram, stress tests). The cardiac-specific biomarkers natriuretic peptides (NPs) and cardiac troponins (cTn) have been proposed as additional tools for risk prediction in the peri-operative period, particularly for the identification of myocardial injury in patients undergoing major non-cardiac surgery. The prognostic information from the measurement of BNP/NT-proBNP and hs-cTn is independent and complementary to other important indicators of risk, also including ECG and imaging techniques. Elevated levels of cardiac-specific biomarkers before surgery are associated with a markedly higher risk of MACE during the peri-operative period. BNP/NT-proBNP and hs-cTn should be measured in all patients during the clinical evaluation before surgery, particularly during intermediate- or high-risk surgery, in patients aged >65 years and/or with comorbidities. Several questions remain to be assessed in dedicated clinical studies, such as how to optimize the management of patients with raised cardiac specific biomarkers before surgery, and whether a strategy based on biomarker measurement improves patient outcomes and is cost-effective.

Prognostic values of high sensitivity cardiac troponin T and I for long-term mortality in hemodialysis patients

Previous studies using contemporary cardiac troponin (cTn) assays have shown conflicting results in predictability of mortality and major adverse cardiovascular events (MACEs) in hemodialysis patients. We aimed to evaluate the prognostic values of high-sensitivity cTnT (hs-cTnT) and hs-cTnI for long-term mortality and MACEs in asymptomatic chronic hemodialysis patients. 198 asymptomatic patients undergoing regular hemodialysis (age 62.4 ± 14.8 years) were enrolled. Pre-dialysis hs-cTnT and hs-cTnI levels were measured. The study outcomes were long-term all-cause mortality and MACEs. Median values of hs-cTnT and hs-cTnI were 61.1 ng/L (IQR 36.6–102.0) and 18.4 ng/L (IQR 9.5–36.6), respectively. During a median follow-up of 13.5 months, 30 (15.1%) patients developed MACEs, and 20 (10.1%) patients died. The patients in highest quartile of hs-cTnT level (≥ 102 ng/L) had increased risk of long-term mortality (HR 3.34; 95%CI 1.39–8.04, P = 0.005). However, hs-cTnI levels above highest quartile (≥ 36 ng/L) was not significantly associated with increased risk of all-cause mortality. Nevertheless, elevated level of hs-cTnT and hs-cTnI was associated with increased risk of MACEs. We demonstrated that higher level of hs-cTnT, but not hs-cTnI, was associated with increased risk of long-term mortality. Nevertheless, higher level of hs-cTnT and hs-cTnI both were associated with greater risk of long-term MACEs.

Natriuretic Peptides and Troponins to Predict Cardiovascular Events in Patients Undergoing Major Non-Cardiac Surgery

Patients undergoing major surgery have a substantial risk of cardiovascular events during the perioperative period. Despite the introduction of several risk scores based on medical history, classical risk factors and non-invasive cardiac tests, the possibility of predicting cardiovascular events in patients undergoing non-cardiac surgery remains limited. The cardiac-specific biomarkers, natriuretic peptides (NPs) and cardiac troponins (cTn) have been proposed as additional tools for risk prediction in the perioperative period. This review paper aims to discuss the value of preoperative levels and perioperative changes in cardiac-specific biomarkers to predict adverse outcomes in patients undergoing major non-cardiac surgery. Based on several prospective observational studies and six meta-analyses, some guidelines recommended the measurement of NPs to refine perioperative cardiac risk estimation in patients undergoing non-cardiac surgery. More recently, several studies reported a higher mortality in surgical patients presenting an elevation in high-sensitivity cardiac troponin T and I, especially in elderly patients or those with comorbidities. This evidence should be considered in future international guidelines on the evaluation of perioperative risk in patients undergoing major non-cardiac surgery.

Accounting for frailty and multimorbidity when interpreting high-sensitivity troponin I tests in oldest old

Background

Older patients evaluated in Emergency Departments (ED) for suspect Myocardial Infarction (MI) frequently exhibit unspecific elevations of serum high‐sensitivity troponin I (hs‐TnI), making interpretation particularly challenging for emergency physicians. The aim of this longitudinal study was to identify the interaction of multimorbidity and frailty with hs‐TnI levels in older patients seeking emergency care.

Methods

A group of patients aged≥75 with suspected MI was enrolled in our acute geriatric ward immediately after ED visit. Multimorbidity and frailty were measured with Cumulative Illness Rating Scale (CIRS) and Clinical Frailty Scale (CFS), respectively. The association of hs‐TnI with MI (main endpoint) was assessed by calculation of the Area Under the Receiver‐Operating Characteristic Curve (AUROC), deriving population‐specific cut‐offs with Youden test. The factors associated with hs‐TnI categories, including MI, CFS and CIRS, were determined with stepwise multinomial logistic regression. The association of hs‐TnI with 3‐month mortality (secondary endpoint) was also investigated with stepwise logistic regression.

Results

Among 268 participants (147 F, median age 85, IQR 80–89), hs‐TnI elevation was found in 191 cases (71%, median 23 ng/L, IQR 11–65), but MI was present in only 12 cases (4.5%). hs‐TnI was significantly associated with MI (AUROC 0.751, 95% CI 0.580–0.922, p = 0.003), with an optimal cut‐off of 141 ng/L. hs‐TnI levels ≥141 ng/L were significantly associated with CFS (OR 1.58, 95% CI 1.15–2.18, p = 0.005), while levels <141 ng/L were associated with the cardiac subscore of CIRS (OR 1.36, 95% CI 1.07–1.71, p = 0.011). CFS, but not hs‐TnI levels, predicted 3‐month mortality.

Conclusions

In geriatric patients with suspected MI, frailty and cardiovascular multimorbidity should be carefully considered when interpreting emergency hs‐TnI testing.

Variability of high-sensitivity cardiac troponin T and I in asymptomatic patients receiving hemodialysis

Variation of high-sensitivity cardiac troponin I and T (hs-cTn) during hemodialysis has been observed. Observational studies demonstrated the increased incidence of adverse cardiovascular events after long compared to short interdialytic intervals. Therefore, we aimed to compare variation of hs-cTnI and hs-cTnT before and after hemodialysis and between short and long interdialytic intervals. We enrolled 200 asymptomatic patients receiving regular hemodialysis. The hs-cTnI and hs-cTnT levels were measured before and after hemodialysis on the day after short and long interdialytic intervals. Mean age was 62.3 ± 14.8 years (Male 55.5%). Prevalence of increased hs-cTnI and hs-cTnT was 34.5% and 99.0%, respectively. The median ± interquartile range of hs-cTnT increased significantly after hemodialysis during short and long interdialytic intervals. However, hs-cTnI level did not increase after hemodialysis during short and long intervals. We found that levels of hs-cTnI and T did not differ between short interdialytic and long interdialytic intervals. We demonstrated higher prevalence of elevated hs-cTnT in patients with regular hemodialysis compared to hs-cTnI. The rise of hs-cTnT was observed immediately after hemodialysis but no significant change of hs-cTnI was noted. Accordingly, hs-cTnI may be preferable as a diagnostic marker in patients with suspected acute myocardial infarction than hs-cTnT.