Cardiac troponins: from myocardial infarction to chronic disease

Clinical relevance and advances in detection of translational biomarker cardiac troponin

Cardiovascular diseases (CVD) are a range of diseases, pointing the functional hindrances in the heart and blood vessels of the human system that contributes to 48.6 % of the world's adult death rate. The diagnosis of CVD relies upon the Electro Cardio Gram (ECG) and detection of muscle markers such as troponins. Among the cardiac trio, Cardiac Troponin I (cTnI) weighing 23 KiloDalton (kDa) is a sorted biomarker for CVD. cTnI remains high in the blood after 1-2 weeks of myocardial damage. Testing of cTnI in CVD patients aids in diagnosis and risk stratification of the disease. Different determination systems including optical, electrochemical, and acoustic have been put forward for monitoring the cTnI which are Point of Care (POC) that promotes simple and sensitive detection of cTnI. The modern era has paved way to high-sensitivity Troponin I (hscTnI) devices that can detect up to 0.01 ng/ml in human blood/plasma/serum. Yet, the practice of hscTnI is impracticable due to cost inefficiency. Development of new hscTnI devices with minimal investment and maximal detection range will meet the global requirement. This review gives an over view on different detection systems of cardiac troponin I which stands as a translational detection molecule for CVDs.

Pericardial fluid troponin in cardiac surgery

BACKGROUND AND OBJECTIVE

Pericardial Fluid (PF) is a rich reservoir of biologically active factors. Due to its proximity to the heart, the biochemical structure of PF may reflect the pathological changes in the cardiac interstitial environment. This manuscript aimed to determine whether the PF level of cardiac troponins changes in patients undergoing cardiac surgery.

METHODS

This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, EMBASE, Cochrane, ClinicalTrials.gov, and Google Scholar databases were electronically searched for primary studies using the keywords "pericardial fluid," "troponin," and "cardiac surgery." The primary outcome of interest was changes in troponin levels within the PF preoperatively and postoperatively. Secondary outcomes of interest included comparisons between troponin level changes in the PF compared to plasma.

RESULTS

A total of 2901 manuscripts were screened through a title and abstract stage by two independent blinded reviewers. Of those, 2894 studies were excluded, and the remaining seven studies underwent a full-text review. Studies were excluded if they did not provide data or failed to meet inclusion criteria. Ultimately, six articles were included that discussed cardiac troponin levels within the PF in patients who had undergone cardiac surgery. Pericardial troponin concentration increased over time after surgery, and levels were significantly higher in PF compared to serum. All studies found that the type of operation did not affect these overall observations.

CONCLUSION

Our review of the literature suggest that the PF level of cardiac troponins increases in patients undergoing cardiac surgery, irrespective of the procedure type. However, these changes' exact pattern and clinical significance remain undefined.

Understanding long COVID myocarditis: A comprehensive review

Infectious diseases are a cause of major concern in this twenty-first century. There have been reports of various outbreaks like severe acute respiratory syndrome (SARS) in 2003, swine flu in 2009, Zika virus disease in 2015, and Middle East Respiratory Syndrome (MERS) in 2012, since the start of this millennium. In addition to these outbreaks, the latest infectious disease to result in an outbreak is the SARS-CoV-2 infection. A viral infection recognized as a respiratory illness at the time of emergence, SARS-CoV-2 has wreaked havoc worldwide because of its long-lasting implications like heart failure, sepsis, organ failure, etc., and its significant impact on the global economy. Besides the acute illness, it also leads to symptoms months later which is called long COVID or post-COVID-19 condition. Due to its ever-increasing prevalence, it has been a significant challenge to treat the affected individuals and manage the complications as well. Myocarditis, a long-term complication of coronavirus disease 2019 (COVID-19) is an inflammatory condition involving the myocardium of the heart, which could even be fatal in the long term in cases of progression to ventricular dysfunction and heart failure. Thus, it is imperative to diagnose early and treat this condition in the affected individuals. At present, there are numerous studies which are in progress, investigating patients with COVID-19-related myocarditis and the treatment strategies. This review focuses primarily on myocarditis, a life-threatening complication of COVID-19 illness, and endeavors to elucidate the pathogenesis, biomarkers, and management of long COVID myocarditis along with pipeline drugs in detail.

Urine high-sensitive troponin I in children cannot offer an applicable alternative to serum

Introduction

In children, congenital heart defects represent the primary cause of increased serum troponin I. The elimination process of cardiac troponin I from the bloodstream and the factors influencing this process remain unknown. The objective of this study was to explore the role of troponin I as an indicator of cardiac damage in children both in serum and urine, a concept previously investigated in adults.

Methods

Our prospective study involved 70 children under 24 months of age. The first group underwent ventricular septal defect repair, while the second group involved children who had undergone partial cavopulmonary anastomosis. For these groups, urine and serum troponin I were assessed on four occasions. The third group, consisting of healthy children, underwent a single measurement of urine troponin I.

Results

Serum troponin I values exhibited an expected elevation in the early postoperative period, followed by a return to lower levels. Significantly higher concentrations of serum troponin I were observed in the first group of children (p < 0.05). A positive correlation was found between troponin I in the first three measurements and cardiopulmonary bypass and aortic cross-clamping time. There was no discernible increase in urine troponin I directly related to myocardial damage; troponin I couldn't be detected in most urine samples.

Discussion

The inability to detect troponin I in urine remains unexplained. Potential explanatory factors may include the isoelectric point of troponin I, elevated urinary concentrations of salts and urea, variations in urine acidity (different pH levels), and a relatively low protein concentration in urine.

Superiority of high sensitivity cardiac troponin I over NT-proBNP and adiponectin for 7-year mortality in stable patients receiving haemodialysis

Patients on haemodialysis (HD) have high mortality risk, and prognostic values of the major cardiovascular biomarkers cardiac troponin I (cTnI), N-terminal pro-brain natriuretic peptide (NT-proBNP), and adiponectin should be ascertained over longer follow-up periods using higher-sensitivity assays, which we undertook. In 221 HD patients, levels of high-sensitivity (hs)-cTnI, NT-proBNP, and adiponectin, were measured using high-sensitivity assays, and their associations with all-cause mortality (ACM) and cardiovascular mortality (CVM) were prospectively investigated for 7 years. Higher hs-cTnI and NT-proBNP levels were significant risk factors for ACM and CVM in the Kaplan-Meier analysis. Multivariate Cox proportional hazards analyses in a model including hs-cTnI and NT-proBNP identified log hs-cTnI, but not log NT-proBNP, as an independent risk factor for ACM (HR 2.12, P < 0.02) and CVM (HR 4.48, P < 0.0005). Stepwise analyses identified a high hs-cTnI tertile as a risk factor for ACM (HR 2.31, P < 0.01) and CVM (HR 6.70, P < 0.001). The addition of hs-cTnI to a model including age, CRP, DM, and NT-proBNP significantly improved the discrimination of ACM and CVM each over 7 years. Conclusively, hs-cTnI was superior to NT-proBNP and adiponectin in predicting ACM and CVM over 7 years in HD patients, suggesting the significance of baseline hs-cTnI measurements in long-term management.

The current paradigm of cardiac troponin increase among athletes

Although it is known that exercise improves cardiovascular health and extends life expectancy, a significant number of people may also experience an elevation in cardiac troponin levels as a result of exercise. For many years, researchers have argued whether exercise-induced cardiac troponin rises are a consequence of a physiological or pathological reaction and whether they are clinically significant. Differences in cardiac troponin elevation and cardiac remodeling can be seen between athletes participating in different types of sports. When forecasting the exercise-induced cardiac troponin rise, there are many additional parameters to consider, as there is a large amount of interindividual heterogeneity in the degree of cardiac troponin elevation. Although it was previously believed that cardiac troponin increases in athletes represented a benign phenomenon, numerous recent studies disproved this notion by demonstrating that, in specific individuals, cardiac troponin increases may have clinical and prognostic repercussions. This review aims to examine the role of cardiac troponin in athletes and its role in various sporting contexts. This review also discusses potential prognostic and clinical implications, as well as future research methods, and provides a straightforward step-by-step algorithm to help clinicians interpret cardiac troponin rise in athletes in both ischemic and non-ischemic circumstances.

Changes in blood metabolomes as potential markers for severity and prognosis in doxorubicin-induced cardiotoxicity: a study in HER2-positive and HER2-negative breast cancer patients

BACKGROUND

We aimed to compare the changes in blood metabolomes and cardiac parameters following doxorubicin treatment in HER2-positive and HER2-negative breast cancer patients. Additionally, the potential roles of changes in blood metabolomes as severity and prognostic markers of doxorubicin-induced cardiotoxicity were determined.

METHODS

HER2-positive (n = 37) and HER2-negative (n = 37) breast cancer patients were enrolled. Cardiac function assessment and blood collection were performed at baseline and 2 weeks after completion of doxorubicin treatment in all patients, as well as at three months after completion of doxorubicin treatment in HER2-negative breast cancer patients. Blood obtained at all three-time points was processed for measuring cardiac injury biomarkers. Blood obtained at baseline and 2 weeks after completion of doxorubicin treatment were also processed for measuring systemic oxidative stress and 85 metabolome levels.

RESULTS

Cardiac injury and systolic dysfunction 2 weeks after completion of doxorubicin treatment were comparable between these two groups of patients. However, only HER2-negative breast cancer patients exhibited increased systemic oxidative stress and cardiac autonomic dysfunction at this time point. Moreover, 33 and 29 blood metabolomes were altered at 2 weeks after completion of doxorubicin treatment in HER2-positive and HER2-negative breast cancer patients, respectively. The changes in most of these metabolomes were correlated with the changes in cardiac parameters, both at 2 weeks and 3 months after completion of doxorubicin treatment.

CONCLUSIONS

The changes in blood metabolomes following doxorubicin treatment were dependent on HER2 status, and these changes might serve as severity and prognostic markers of doxorubicin-induced cardiotoxicity.

TRIAL REGISTRATION

The study was conducted under ethical approval from the Institutional Review Board of the Faculty of Medicine, Chiang Mai University (Registration number: MED-2563-07001; Date: April 28, 2020). The study also complied with the Declaration of Helsinki.

Machine Learning-Based Model for Predicting Prolonged Mechanical Ventilation in Patients with Congestive Heart Failure

BACKGROUND

Mechanical ventilation (MV) is widely used to relieve respiratory failure in patients with congestive heart failure (CHF). Prolonged MV (PMV) is associated with a poor prognosis. We aimed to establish a prediction model based on machine learning (ML) algorithms for the early identification of patients with CHF requiring PMV.

METHODS

Twelve commonly used ML algorithms were used to build the prediction model. The least absolute shrinkage and selection operator (LASSO) regression was employed to select the key features. We examined the area under the curve (AUC) statistics to evaluate the prediction performance. Data from another database were used to conduct external validation.

RESULTS

We screened out 10 key features from the initial 65 variables via LASSO regression to improve the practicability of the model. The CatBoost model showed the best performance for predicting PMV among the 12 commonly used ML algorithms, with favorable discrimination (AUC = 0.790) and calibration (Brier score = 0.154). Moreover, hospital mortality could be accurately predicted using the CatBoost model as well (AUC = 0.844). In the external validation, the CatBoost model also showed satisfactory prediction performance (AUC = 0.780), suggesting certain generalizability of the model. Finally, a nomogram with risk classification of PMV was shown in this study.

CONCLUSION

The present study developed and validated a CatBoost model, which could accurately predict PMV in mechanically ventilated patients with CHF. Moreover, this model has a favorable performance in predicting hospital mortality in these patients.

Pathophysiological mechanisms underlying increased circulating cardiac troponin in noncardiac surgery: a narrative review

Assay-specific increases in circulating cardiac troponin are observed in 20-40% of patients after noncardiac surgery, depending on patient age, type of surgery, and comorbidities. Increased cardiac troponin is consistently associated with excess morbidity and mortality after noncardiac surgery. Despite these findings, the underlying mechanisms are unclear. The majority of interventional trials have been designed on the premise that ischaemic cardiac disease drives elevated perioperative cardiac troponin concentrations. We consider data showing that elevated circulating cardiac troponin after surgery could be a nonspecific marker of cardiomyocyte stress. Elevated concentrations of circulating cardiac troponin could reflect coordinated pathological processes underpinning organ injury that are not necessarily caused by ischaemia. Laboratory studies suggest that matching of coronary artery autoregulation and myocardial perfusion-contraction coupling limit the impact of systemic haemodynamic changes in the myocardium, and that type 2 ischaemia might not be the likeliest explanation for cardiac troponin elevation in noncardiac surgery. The perioperative period triggers multiple pathological mechanisms that might cause cardiac troponin to cross the sarcolemma. A two-hit model involving two or more triggers including systemic inflammation, haemodynamic strain, adrenergic stress, and autonomic dysfunction might exacerbate or initiate acute myocardial injury directly in the absence of cell death. Consideration of these diverse mechanisms is pivotal for the design and interpretation of interventional perioperative trials.

Dual-Encoded Affinity Microbead Signature Combinatorial Profiling for Acute Myocardial Infarction High-Sensitivity Diagnosis

The early diagnosis of acute myocardial infarction (AMI) is dependent on the combined feedback of multiple cardiac biomarkers. However, it remains challenging to precisely detect multicardiac biomarkers in complex blood early due to the lack of sensitive and specific diagnostic indicators and the low abundance and small size of associated biomarkers with high specificity (such as microRNAs). To make matters worse, spectral overlap significantly limits the multiplex analysis of cardiac biomarkers by fluorescent probes, leading to bias in the diagnosis of myocardial infarction. Herein, we developed a method for simultaneous detection of miRNAs and protein biomarkers using size- and color-coded microbeads that carry signature for target capture. We also constructed a microfluidic chip with different spacer arrays that segregate these microbeads in different chip regions according to their size to produce signature signals, indicating the level of different biomarkers. The signals on the microbeads were hugely amplified by catalytic hairpin assembly and rolling circle amplification. Notably, this strategy enables the simultaneous and in situ sensitive profiling of six kinds of biomarkers via adding two different fluorescent labels, removing the limitations of spectral overlap. We envision that the strategy has great potential for application in clinical diagnosis for AMI.

Troponin T is elevated in a relevant proportion of patients with 5q-associated spinal muscular atrophy

Troponin T concentration (TNT) is commonly considered a marker of myocardial damage. However, elevated concentrations have been demonstrated in numerous neuromuscular disorders, pointing to the skeletal muscle as a possible extracardiac origin. The aim of this study was to determine disease-related changes of TNT in 5q-associated spinal muscular atrophy (SMA) and to screen for its biomarker potential in SMA. We therefore included 48 pediatric and 45 adult SMA patients in this retrospective cross-sequential observational study. Fluid muscle integrity and cardiac markers were analyzed in the serum of treatment-naïve patients and subsequently under disease-modifying therapies. We found a TNT elevation in 61% of SMA patients but no elevation of the cardiospecific isoform Troponin I (TNI). TNT elevation was more pronounced in children and particularly infants with aggressive phenotypes. In adults, TNT correlated to muscle destruction and decreased under therapy only in the subgroup with elevated TNT at baseline. In conclusion, TNT was elevated in a relevant proportion of patients with SMA with emphasis in infants and more aggressive phenotypes. Normal TNI levels support a likely extracardiac origin. Although its stand-alone biomarker potential seems to be limited, exploring TNT in SMA underlines the investigation of skeletal muscle integrity markers.

An auxiliary strategy of partial least squares regression in pharmacokinetic/pharmacodynamic studies: A case of application of guhong injection in myocardial ischemia/reperfusion rats

Guhong injection (GHI) has been applied in the therapy of cardio-cerebrovascular disease in clinic, but there is no report about the pharmacokinetic/pharmacodynamic (PK/PD) research on GHI treating myocardial ischemia/reperfusion (MI/R) injury in rats. In this study, eight compounds of GHI in plasma, including N-acetyl-L-glutamine (NAG), chlorogenic acid (CGA), hydroxysafflor yellow A (HSYA), p-coumaric acid ( pCA), rutin, hyperoside, kaempferol-3-O-rutinoside, and kaempferol-3-O-glucoside, were quantified by LC-MS/MS. We discovered that the values of t1/2β, k12, V2, and CL2 were larger than those of t1/2α, k21, V1, and CL1 for all compounds. The levels of four biomarkers, creatine kinase-MB (CK-MB), cardiac troponin I (cTn I), ischemia-modified albumin (IMA), and alpha-hydroxybutyrate dehydrogenase (α-HBDH) in plasma were determined by ELISA. The elevated level of these biomarkers induced by MI/R was declined to different degrees via administrating GHI and verapamil hydrochloride (positive control). The weighted regression coefficients of NAG, HSYA, CGA, and pCA in PLSR equations generated from The Unscrambler X software (version 11) were mostly minus, suggesting these four ingredients were positively correlated to the diminution of the level of four biomarkers. Emax and ED50, two parameters in PK/PD equations that were obtained by adopting Drug and Statistics software (version 3.2.6), were almost enlarged with the rise of GHI dosage. Obviously, all analytes were dominantly distributed and eliminated in the peripheral compartment with features of rapid distribution and slow elimination. With the enhancement of GHI dosage, the ingredients only filled in the central compartment if the peripheral compartment was replete. Meanwhile, high-dose of GHI generated the optimum intrinsic activity, but the affinity of compounds with receptors was the worst, which may be caused by the saturation of receptors. Among the eight analytes, NAG, HSYA, CGA, and pCA exhibited superior cardioprotection, which probably served as the pharmacodynamic substance basis of GHI in treating MI/R injury.

High-Sensitivity Cardiac Troponins in Patients With Chest Pain and Treatment With Oral Antineoplastic Agents Associated With Cardiovascular Toxicity

BACKGROUND

Knowledge is limited on the clinical implications of high-sensitivity cardiac troponin (hs-cTn) measurements in patients treated with oral antineoplastic agents associated with cardiovascular side effects. This study investigated the diagnostic performance of hs-cTnT for myocardial infarction.

METHODS

Among all visits to 7 different emergency departments (EDs) from December 9, 2010 to August 31, 2017, we included visits by patients presenting with chest pain who had ≥1 hs-cTnT measured. Patients treated with oral antineoplastic agents associated with cardiovascular toxicity were identified. Logistic regression models were used to estimate the performance of hs-cTnT for diagnosing myocardial infarction.

RESULTS

We identified 214,165 visits, of which 2695 (1.3%) occurred in patients with oral antineoplastic treatment associated with cardiovascular toxicity. Treatment was associated with a higher myocardial infarction incidence (8.2% vs 5.7%), but the overall diagnostic accuracy for a myocardial infarction was lower in patients with versus without treatment, paralleled by a lower specificity and PPV with the 0 h hs-cTnT rule-in cut-off of 52 ng/L (92.6% [95% CI: 91.6-93.6] vs 96.8% [95% CI: 96.8-96.9], and 42.8 [95% CI: 37.4-48.2] vs 49.5 [95% CI: 48.6-50.4], respectively). The majority (72%) of patients with treatment were assigned to an intermediate risk group, in whom the risk of myocardial infarction was reduced by 29% (OR 0.71, 95% CI: 0.57-0.89).

CONCLUSIONS

Diagnostic accuracy of hs-cTnT for myocardial infarction is reduced among patients on treatment with oral antineoplastic agents associated with cardiovascular toxicity. Most patients would be assigned to an intermediate risk group, in whom only 4% will have a final myocardial infarction diagnosis.

Biosensing Platforms for Cardiac Biomarker Detection

Myocardial infarction (MI) is a cardiovascular disease that occurs when there is an elevated demand for myocardial oxygen as a result of the rupture or erosion of atherosclerotic plaques. Globally, the mortality rates associated with MI are steadily on the rise. Traditional diagnostic biomarkers employed in clinical settings for MI diagnosis have various drawbacks, prompting researchers to investigate fast, precise, and highly sensitive biosensor platforms and technologies. Biosensors are analytical devices that combine biological elements with physicochemical transducers to detect and quantify specific compounds or analytes. These devices play a crucial role in various fields including healthcare, environmental monitoring, food safety, and biotechnology. Biosensors developed for the detection of cardiac biomarkers are typically electrochemical, mass, and optical biosensors. Nanomaterials have emerged as revolutionary components in the field of biosensing, offering unique properties that significantly enhance the sensitivity and specificity of the detection systems. This review provides a comprehensive overview of the advancements and applications of nanomaterial-based biosensing systems. Beginning with an exploration of the fundamental principles governing nanomaterials, we delve into their diverse properties, including but not limited to electrical, optical, magnetic, and thermal characteristics. The integration of these nanomaterials as transducers in biosensors has paved the way for unprecedented developments in analytical techniques. Moreover, the principles and types of biosensors and their applications in cardiovascular disease diagnosis are explained in detail. The current biosensors for cardiac biomarker detection are also discussed, with an elaboration of the pros and cons of existing platforms and concluding with future perspectives.

Metronidazole promotes oxidative stress and DNA fragmentation-mediated myocardial injury in albino mice

The purpose of the present study was to investigate the cardiotoxic effects of Metronidazole (Mtz) in albino mice. The mice were divided into four experimental groups: Gp.I (control group): saline, Gp.II:125 mg/kg b.w Mtz, Gp.III:250 mg/kg b.w, Gp.IV:500 mg/kg b.w Mtz. Heart weight ratio, markers of cardiac injury, markers of oxidative stress, histopathological examinations, DNA fragmentation and spectral analysis were used to determine cardiotoxicity. Administration of 125-500 mg/kg Mtz caused an increase in heart weight and a decrease in body weight. Administration of 500 mg/kg Mtz increased heart weight by 35.5% and decreased body weight by 21.9% compared with control. Mtz-treated mice showed a significant increase in cardiac injury biomarkers and serious alterations in cardiac oxidative stress markers. Histopathological changes of cardiac tissues observed in mice treated with Mtz include myocardial hypertrophy, fibrosis, myocarditis, separation of the muscle fibers, congestion-narrowing in vessels, necrosis, myocardium-vacuolation, myocytolysis, myocyte degeneration, nuclear aggregation, cytoplasmic fragmentation and prevalent nuclei. Mtz treatment already resulted in a significant decrease in the percentage of head DNA and an increase in the percentage of tail DNA. The most striking tail formation among the Mtz-treated groups was observed in the group receiving 500 mg/kg Mtz. In the presence of Mtz, there was a hypochromic shift in the absorption spectrum of DNA, and the potential DNA-Mtz interaction was found to occur in the intercalation mode. These results show that Mtz used against anaerobic bacteria and protozoa in gastrointestinal infections can cause severe cardiotoxic findings in albino mice and cause fragmentation in DNA.

Prognostic value of high-sensitive troponin T in patients with severe aortic stenosis undergoing valve replacement surgery

Background

Aortic stenosis (AS) is a well-known cause of mortality. We aimed to assess the prognostic value of high-sensitive troponin T (hs-TnT) in symptomatic patients with severe AS and preserved left ventricular ejection fraction (LVEF) after surgical aortic valve replacement (AVR).

Patients and methods

The study recruited patients with severe symptomatic AS fulfilling the inclusion criteria in the period between April 2020 and February 2022. Comprehensive echocardiography was done. The following parameters were assessed: AS severity, LV mass index (LVMI), left atrium volume index (LAVI), and LVEF. E/e' and LVEF were calculated using the biplane method of Simpsons. Global longitudinal strain (GLS) was assessed by speckle tracking echocardiography. Peripheral blood samples were collected for hs-TnT measurement. All patients underwent surgical AVR. The patients were followed for the following 6 months for major adverse cardiovascular events (MACE). MACE was defined as cardiac death, re-admission for congestive heart failure (CHF) and fatal arrhythmia.

Results

One hundred and eight patients (mean age = 58.7 ± 7.68 years) with severe AS were recruited. Seventeen patients presented with MACE including 8 cardiac deaths. We divided the patients into two groups based on the normal hs-TnT values. The Kaplan-Meier curve revealed a statistically significant difference in MACE rate among troponin groups (log-rank test = 5.06, p = 0.025). There was significant difference between both groups regarding GLS with smaller GLS in negative hs-TnT group. In multivariate analysis, GLS and hs-TnT were significantly associated with MACE (p = 0.022 and < 0.01 respectively). The cutoff value of hs-TnT of 238.25 had a sensitivity of 70% and a specificity of 81% for predicting future MACE. There was a significant correlation between GLS and troponin (p < 0.001).

Conclusions

hs-TnT is associated with bad short-term prognosis after AVR. hs-TnT and GLS could be significant predictors for future MACE in patients with severe symptomatic AS and preserved LVEF who underwent AVR. Elevated hs-TnT and impaired GLS could set an indication of early intervention in asymptomatic severe AS.

Clinical Interpretation of Serum Troponin in the Era of High-Sensitivity Testing

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

Photodynamic Therapy for Atherosclerosis

Atherosclerosis, which currently contributes to 31% of deaths globally, is of critical cardiovascular concern. Current diagnostic tools and biomarkers are limited, emphasizing the need for early detection. Lifestyle modifications and medications form the basis of treatment, and emerging therapies such as photodynamic therapy are being developed. Photodynamic therapy involves a photosensitizer selectively targeting components of atherosclerotic plaques. When activated by specific light wavelengths, it induces localized oxidative stress aiming to stabilize plaques and reduce inflammation. The key advantage lies in its selective targeting, sparing healthy tissues. While preclinical studies are encouraging, ongoing research and clinical trials are crucial for optimizing protocols and ensuring long-term safety and efficacy. The potential combination with other therapies makes photodynamic therapy a versatile and promising avenue for addressing atherosclerosis and associated cardiovascular disease. The investigations underscore the possibility of utilizing photodynamic therapy as a valuable treatment choice for atherosclerosis. As advancements in research continue, photodynamic therapy might become more seamlessly incorporated into clinical approaches for managing atherosclerosis, providing a blend of efficacy and limited invasiveness.

Integrating Cardiac Biomarkers and Electrocardiogram in Pulmonary Embolism Prognosis

Pulmonary embolism (PE) represents a significant clinical challenge that substantially impacts healthcare systems. This case report focuses on the nuances of risk stratification in PE, highlighted through the presentation of a 64-year-old female patient. The uniqueness of this case lies in the patient's atypical presentation, where decreased exercise tolerance was the sole symptom leading to the diagnosis of PE. The patient was found to have new-onset atrial fibrillation, elevated levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), and signs of right ventricular strain on imaging. This scenario underscores the necessity for a comprehensive assessment in PE cases, particularly when classic symptoms (e.g., tachycardia, shortness of breath, chest pain) are absent. We explore the incidence of PE in patients diagnosed with deep vein thrombosis, examining the critical role of cardiac biomarkers, including B-type natriuretic peptide, NT-proBNP, and troponins, in prognostication and their potential use in risk assessment tools for PE patients. Additionally, the significance of electrocardiogram evaluation in these patients and its role in risk stratification is thoroughly assessed.

Electrochemically Synthesized MIP Sensors: Applications in Healthcare Diagnostics

Early-stage detection and diagnosis of diseases is essential to the prompt commencement of treatment regimens, curbing the spread of the disease, and improving human health. Thus, the accurate detection of disease biomarkers through the development of robust, sensitive, and selective diagnostic tools has remained cutting-edge scientific research for decades. Due to their merits of being selective, stable, simple, and having a low preparation cost, molecularly imprinted polymers (MIPs) are increasingly becoming artificial substitutes for natural receptors in the design of state-of-the-art sensing devices. While there are different MIP preparation approaches, electrochemical synthesis presents a unique and outstanding method for chemical sensing applications, allowing the direct formation of the polymer on the transducer as well as simplicity in tuning the film properties, thus accelerating the trend in the design of commercial MIP-based sensors. This review evaluates recent achievements in the applications of electrosynthesized MIP sensors for clinical analysis of disease biomarkers, identifying major trends and highlighting interesting perspectives on the realization of commercial MIP-endowed testing devices for rapid determination of prevailing diseases.

Natriuretic peptides: Another tool for the management of cancer?

The connection between heart failure (HF) and cancer through multiple pathways such as inflammation, oxidative stress, and neurohormonal activation, among others, is well established. As a consequence, increases in plasma levels of several biomarkers have been described in both disorders. The most consistent information is related to natriuretic peptides (NPs). Although they are known to be produced in the ventricles as a response to myocardial distension, and thus can be useful for the diagnosis and prognosis of HF, and also for the management of chemotherapy-induced myocardial damage, they are also produced by tumour cells. In this regard, increased plasma levels of NPs have been described in patients with multiple malignancies in the absence of volume overload. Natriuretic peptide levels have been shown to correlate directly with the extension of tumours and with poorer outcomes. Moreover, some data indicate that they may help in the detection of subclinical tumours. Given that these peptides have been described to have anti-proliferative and anti-angiogenic effects, a plausible hypothesis is that they may be produced by tumours as a negative feed-back mechanism to avoid tumour progression. This would lead to increased levels of NPs in plasma that could be potentially useful for early detection of malignancies as well as for a prognostic assessment. Nevertheless, since the sample size of many studies published so far is limited, more data are needed to provide consistent data in order to confirm or rule out this hypothesis.

Optimizing the Clinical Use of High-Sensitivity Troponin Assays: A Review

Ischemic heart diseases (IHDs) remain a global health concern. Many IHD cases go undiagnosed due to challenges in the initial diagnostic process, particularly in cases of acute myocardial infarction (AMI). High-sensitivity cardiac troponin (hs-cTn) assays have revolutionized myocardial injury assessment, but variations in diagnostic cut-off values and population differences have raised challenges. This review addresses essential laboratory and clinical considerations for hs-cTn assays. Laboratory guidelines discuss the importance of establishing standardized 99th-percentile upper reference limits (URLs) considering factors such as age, sex, health status, and analytical precision. The reference population should exclude individuals with comorbidities like diabetes and renal disease, and rigorous selection is crucial. Some clinical guidelines emphasize the significance of sex-specific URL limits while others do not. They highlight the use of serial troponin assays for AMI diagnosis. In addition, timely reporting of accurate hs-cTn results is essential for effective clinical use. This review aims to provide a clearer understanding among laboratory professionals and clinicians on how to optimize the use of hs-cTn assays in clinical settings in order to ensure accurate AMI diagnosis and thus improve patient care and outcomes.

Structure and dynamics of endogenous cardiac troponin complex in human heart tissue captured by native nanoproteomics

Protein complexes are highly dynamic entities that display substantial diversity in their assembly, post-translational modifications, and non-covalent interactions, allowing them to play critical roles in various biological processes. The heterogeneity, dynamic nature, and low abundance of protein complexes in their native states present challenges to study using conventional structural biology techniques. Here we develop a native nanoproteomics strategy for the enrichment and subsequent native top-down mass spectrometry (nTDMS) analysis of endogenous cardiac troponin (cTn) complex directly from human heart tissue. The cTn complex is enriched and purified using peptide-functionalized superparamagnetic nanoparticles under non-denaturing conditions to enable the isotopic resolution of cTn complex, revealing their complex structure and assembly. Moreover, nTDMS elucidates the stoichiometry and composition of the cTn complex, localizes Ca2+ binding domains, defines cTn-Ca2+ binding dynamics, and provides high-resolution mapping of the proteoform landscape. This native nanoproteomics strategy opens a paradigm for structural characterization of endogenous native protein complexes.

Differentiating Cardiac Troponin Levels During Cardiac Myosin Inhibition or Cardiac Myosin Activation Treatments: Drug Effect or the Canary in the Coal Mine?

PURPOSE OF REVIEW

Cardiac myosin inhibitors (CMIs) and activators are emerging therapies for hypertrophic cardiomyopathy (HCM) and heart failure with reduced ejection fraction (HFrEF), respectively. However, their effects on cardiac troponin levels, a biomarker of myocardial injury, are incompletely understood.

RECENT FINDINGS

In patients with HCM, CMIs cause substantial reductions in cardiac troponin levels which are reversible after stopping treatment. In patients with HFrEF, cardiac myosin activator (omecamtiv mecarbil) therapy cause modest increases in cardiac troponin levels which are reversible following treatment cessation and not associated with myocardial ischaemia or infarction. Transient changes in cardiac troponin levels might reflect alterations in cardiac contractility and mechanical stress. Such transient changes might not indicate cardiac injury and do not appear to be associated with adverse outcomes in the short to intermediate term. Longitudinal changes in troponin levels vary depending on the population and treatment. Further research is needed to elucidate mechanisms underlying changes in troponin levels.

Long-term prognostic value of high-sensitivity cardiac troponin-I in patients with idiopathic dilated cardiomyopathy

Our objective was to evaluate the long-term prognostic value of high-sensitivity cardiac troponin-I (hs-cTn-I) in idiopathic dilated cardiomyopathy (DCM). First, patients were divided into an end-event group (n = 55) and a non-end-event group (n = 67). Then, patients were included in the subgroup analysis to compare the diagnostic value of brain natriuretic peptide (BNP) and hs-cTn-I in different populations. hs-cTn-I and BNP concentrations were higher in the end-event group. The Cox regression analysis indicated that high hs-cTn-I was a risk factor for poor long-term prognosis. Receiver operating characteristic analysis showed that the area under the curve (AUC) for hs-cTn-I to predict end events was 0.751, and the AUC for BNP was 0.742. The correlation analysis suggested that hs-cTn-I was related to the percentage change in left ventricular internal diameter at end-diastolic and left ventricular ejection fraction. Subgroup analysis showed that compared with BNP, hs-cTn-I was more suitable for predicting end events in patients with preserved renal function (AUC: 0.853 vs 0.712, P = 0.04). In conclusion, hs-cTn-I is a potential biomarker for evaluating long-term prognosis in idiopathic DCM, and its predictive value is higher than that of BNP in patients with preserved renal function.

Subclinical myocardial injury increases the risk of heart failure in patients with and without type 2 diabetes post-acute coronary syndrome

BACKGROUND

Little is known about the effect of subclinical myocardial injury (sMi) on heart failure (HF) risk after acute coronary syndrome (ACS). We examined the frequency patterns of sMi after ACS among patients with and without diabetes mellitus (DM), and the influence of sMis on HF risk at 1 year.

METHODS

Fifty patients with ACS who underwent revascularization were prospectively enrolled. After discharge, serial study visits were conducted and high-sensitivity cardiac troponin T (hs-TnT) levels were checked at 3-month intervals for 1 year. sMi was defined as hs-TnT ≥14 ng/L without clinical symptoms. The primary endpoint was a composite of post-ACS chronic HF or significant left ventricular (LV) dysfunction without HF symptoms. A multivariable logistic regression model was used for risk evaluation.

RESULTS

The mean patient age was 58 years, and 90% were men. Overall, 44% of patients had DM, and the median LV ejection fraction at discharge was 56%. Patients with DM had a higher incidence of sMi than those without DM (63.6% vs. 32.1%, P < 0.05). sMi occurred at least twice in most patients, and the prevalence declined over time in DM, but not in non-DM. Fourteen patients (28%) met the primary endpoint at 1 year, and the risk was higher in patients with DM (odds ratio: 4.99) and patients with sMi (odds ratio: 6.26). However, sMi was not a mediator of the association between DM and HF risk.

CONCLUSIONS

Patients with DM had a higher incidence of sMi. Nonetheless, sMi increased the risk of HF after ACS, irrespective of diabetes status.

The Prognostic Value of Creatine Kinase-MB Dynamics after Primary Angioplasty in ST-Elevation Myocardial Infarctions

BACKGROUND

In STEMIs, the evaluation of the relationship between biomarkers of myocardial injury and patients' prognoses has not been completely explored. Increased levels of CK-MB in patients with a STEMI undergoing primary angioplasty are known to be associated with higher mortality rates, yet the correlation of these values with short-term evolution remains unknown.

MATERIAL AND METHODS

The research encompassed a sample of 80 patients diagnosed with STEMIs, and its methodology entailed a retrospective analysis of the data collected during their hospital stays. The study population was then categorized into three distinct analysis groups based on the occurrence or absence of acute complications and fatalities.

RESULTS

The findings indicated that there is a notable correlation between rising levels of CK-MB upon admission and peak CK-MB levels with a reduction in left ventricular ejection fraction. Moreover, the CK-MB variation established a point of reference for anticipating complications at 388 U/L, and a cut-off value for predicting death at 354 U/L.

CONCLUSION

CK-MB values are reliable indicators of the progress of patients with STEMIs. Furthermore, the difference between the peak and admission CK-MB levels demonstrates a high accuracy of predicting complications and has a significant predictive power to estimate mortality risk.

16α-OHE1, a novel oestrogen metabolite, attenuates dysfunction of left ventricle contractility via regulation of autophagy after myocardial ischemia and reperfusion

BACKGROUND

Myocardial ischemia-reperfusion (MI/R) can exacerbate the initial cardiac damage in the myocardial functional changes, including dysfunction of left ventricular contractility. Oestrogen has been proven to protect the cardiovascular system. However, whether the oestrogen or its metabolites play the main role in attenuating dysfunction of left ventricular contractility is unknown.

METHODS AND RESULTS

This study used the LC-MS/MS to detect oestrogen and its metabolites in clinical serum samples (n = 62) with heart diseases. After correlation analysis with markers of myocardial injury including cTnI (P < 0.01), CK-MB (P < 0.05), and D-Dimer (P < 0.001), 16α-OHE1 was identified. The result from LC-MS/MS in female and ovariectomised (OVX) rat serum samples (n = 5) matched the findings in patients. In MI/R model of animal, the recovery of left ventricular developed pressure (LVDP), rate pressure product (RPP), dp/dtmax and dp/dtmin after MI/R in OVX or male group were worsened than those in female group. Also, the infarction area of OVX or male group was larger than that in females (n = 5, p < 0.01). Furthermore, LC3 II in the left ventricle of OVX and male group was lower than that in females (n = 5, p < 0.01) by immunofluorescence. In H9C2 cells, after the application of 16α-OHE1, the number of autophagosomes was further increased and other organelles improved in MI/R. Simultaneously, LC3 II, Beclin1, ATG5, and p-AMPK/AMPK were increased, and p-mTOR/mTOR was decreased (n = 3, p < 0.01) by Simple Western.

CONCLUSION

16α-OHE1 could attenuate left ventricle contractility dysfunction via autophagy regulation after MI/R, which also offered fresh perspectives on therapeutical treatment for attenuating MI/R injury.

Miniaturized microarray-format digital ELISA enabled by lithographic protein patterning

The search for reliable protein biomarker candidates is critical for early disease detection and treatment. However, current immunoassay technologies are failing to meet increasing demands for sensitivity and multiplexing. Here, the authors have created a highly sensitive protein microarray using the principle of single-molecule counting for signal amplification, capable of simultaneously detecting a panel of cancer biomarkers at sub-pg/mL levels. To enable this amplification strategy, the authors introduce a novel method of protein patterning using photolithography to subdivide addressable arrays of capture antibody spots into hundreds of thousands of individual microwells. This allows for the total sensor area to be miniaturized, increasing the total possible multiplex capacity. With the immunoassay realized on a standard 75x25 mm form factor glass substrate, sample volume consumption is minimized to <10 μL, making the technology highly efficient and cost-effective. Additionally, the authors demonstrate the power of their technology by measuring six secretory factors related to glioma tumor progression in a cohort of mice. This highly sensitive, sample-sparing multiplex immunoassay paves the way for researchers to track changes in protein profiles over time, leading to earlier disease detection and discovery of more effective treatment using animal models.

A Convergent fabrication of silk fibroin nanoparticles on quercetin loaded metal-organic frameworks for promising nanocarrier of myocardial infraction

The biomacromolecule silk fibroin (SF) may be constructed to promote biomimetic nucleation and nanostructures of inorganic nanomaterials, offering it a promising candidate for use in various biomimetic applications. We combined SF-NPs and ZIF-8-NPs to fabricate new drug vehicles that effectively release the drug. SF nanoparticles (SF-NPs) were assembled into quercetin (QCT), a myocardial drug added to fabricate QSF-NPs. By acting as a template for the ZIF-8 nucleation onto the surface, the QSF-NPs fabricated core-shell-structured nanocomposites (named QSF@Z-NCs) with ZIF-8 as the core-shell and the QSF-NPs. The biocompatibility analysis using the MTT assay revealed that the developed QCT, SF-NPs, and QSF@Z-NCs are not harmful to cardiac myoblast (H9C2) cells. The in vivo model demonstrated that H9C2 cells encouraged cardiomyocyte fibre regeneration in myocardial infarction rats. We fabricated a brand-new technique using H9C2 cells and QSF@Z-NCs that might encourage the healing processes in myocardial ischemia cells. This study's results demonstrate that it successfully treats myocardial injury.

Exploring the Clinical Utility of Raman Spectroscopy for Point-of-Care Cardiovascular Disease Biomarker Detection

A variety of innovative point-of-care (POC) solutions using Raman systems have been explored. However, the vast effort is in assay development, while studies of the characteristics required for Raman spectrometers to function in POC applications are lacking. In this study, we tested and compared the performance of eight commercial Raman spectrometers ranging in size from benchtop Raman microscopes to portable and handheld Raman spectrometers using paper fluidic cartridges, including their ability to detect cardiac troponin I and heart fatty acid binding protein, both of which are well-established biomarkers for evaluating cardiovascular health. Each spectrometer was evaluated in terms of excitation wavelength, laser characteristics, and ease of use to investigate POC utility. We found that the Raman spectrometers equipped with 780 and 785 nm laser sources exhibited a reduced background signal and provided higher sensitivity compared to those with 633 and 638 nm laser sources. Furthermore, the spectrometer equipped with the single acquisition line readout functionality showed improved performance when compared to the point scan spectrometers and allowed measurements to be made faster and easier. The portable and handheld spectrometers also showed similar detection sensitivity to the gold standard instrument. Lastly, we reduced the laser power for the spectrometer with single acquisition line readout capability to explore the system performance at a laser power that change the classification from a Class 3B laser device to a Class 3R device and found that it showed comparable performance. Overall, these findings show that portable Raman spectrometers have the potential to be used in POC settings with accuracy comparable to laboratory-grade instruments, are relatively low-cost, provide fast signal readout, are easy to use, and can facilitate access for underserved communities.

Moxibustion enables protective effects on rheumatoid arthritis-induced myocardial injury transforming growth factor beta1 signaling and metabolic reprogramming

OBJECTIVE

To examine the effects of moxibustion on myocardial injury and myocardial metabolomics in rats with rheumatoid arthritis (RA) based on the transforming growth factor beta1 (TGF-β1)/Smads signaling pathway.

METHODS

One hundred rats were treated with saline [normal control (NC) group] or complete Freund's adjuvant (CFA) by right plantar injection for the RA model group, and the latter were randomly divided into 4 groups. Tripterygium wilfordii polyglycoside tablets (, TPT) have anti-inflammatory and are widely used in the clinical treatment of RA, therefore serving as a positive control group. Three days post injection rats were given TPT tablet (TPT group), acupuncture therapy (APT group), and moxibustion treatment (MOX group) for 15 consecutive days, while NC group and model group were equally grasped and fixed and received normal saline. Rat joint swelling scores and arthritis index (AI) were evaluated in each group before the CFA challenge, therapy and after receiving therapy. Myocardial ultrastructure was observed by electron microscope. Enzyme-linked immunosorbent assay was used to detect cardiac troponin I (cTnI) levels in rat myocardial tissue. Quantitative reverse transcription polymerase chain reaction and Western blotting analysis were used to measure the mRNA and protein levels of TGF-β signaling molecules including TGF-β1, Smad2, Smad3, Smad4, and Smad7. Myocardial metabolomics was analyzed using gas chromatography-mass spectrometer.

RESULTS

Compared with model group, RA model rats receiving TPT, acupuncture, or moxibustion therapy all showed reduced joint swelling scores and AI (all P < 0.01) and improved myocardial damage, whereas rats treated with moxibustion were found to be more marked. Consistently, the expressions of cTnI, TGF-β1, Smad2, Smad3, and Smad4 were found to be elevated in model rat group in contrast to NC rats and were significantly downregulated in TPT, APT and MOX group when compared with model group, while the levels of Smad7 showed the opposite result (all P < 0.01). Moreover, the dissection of metabolomics suggested a novel metabolite biomarker panel including D-Xylulose 5-phosphate, dihydroxyacetone phosphate, arachidonic acid, etc was defined and implicated in amino acid, glucose, and fatty acid metabolic processes as revealed by principal component analysis and partial least squares discriminant analysis.

CONCLUSION

Moxibustion prevents RA-induced inflammatory response and offers potent therapeutic effects on myocardial dysfunctions. The protective effects might be associated with its role in TGF-β1 inactivation and metabolic reprogramming.

Cardiac imaging and biomarkers for assessing myocardial fibrosis in children with hypertrophic cardiomyopathy

BACKGROUND

Myocardial fibrosis, as diagnosed on cardiac magnetic resonance imaging (cMRI) by late gadolinium enhancement (LGE), is associated with adverse outcomes in adults with hypertrophic cardiomyopathy (HCM), but its prevalence and magnitude in children with HCM have not been established. We investigated: (1) the prevalence and extent of myocardial fibrosis as detected by LGE cMRI; (2) the agreement between echocardiographic and cMRI measurements of cardiac structure; and (3) whether serum concentrations of N-terminal pro hormone B-type natriuretic peptide (NT-proBNP) and cardiac troponin-T are associated with cMRI measurements.

METHODS

A cross-section of children with HCM from 9 tertiary-care pediatric heart centers in the U.S. and Canada were enrolled in this prospective NHLBI study of cardiac biomarkers in pediatric cardiomyopathy (ClinicalTrials.gov Identifier: NCT01873976). The median age of the 67 participants was 13.8 years (range 1-18 years). Core laboratories analyzed echocardiographic and cMRI measurements, and serum biomarker concentrations.

RESULTS

In 52 children with non-obstructive HCM undergoing cMRI, overall low levels of myocardial fibrosis with LGE >2% of left ventricular (LV) mass were detected in 37 (71%) (median %LGE, 9.0%; IQR: 6.0%, 13.0%; range, 0% to 57%). Echocardiographic and cMRI measurements of LV dimensions, LV mass, and interventricular septal thickness showed good agreement using the Bland-Altman method. NT-proBNP concentrations were strongly and positively associated with LV mass and interventricular septal thickness (P < .001), but not LGE.

CONCLUSIONS

Low levels of myocardial fibrosis are common in pediatric patients with HCM seen at referral centers. Longitudinal studies of myocardial fibrosis and serum biomarkers are warranted to determine their predictive value for adverse outcomes in pediatric patients with HCM.

Hepatic ischemia-reperfusion syndrome and its effect on the cardiovascular system: The role of treprostinil, a synthetic prostacyclin analog

Hepatic ischemia-reperfusion syndrome has been the subject of intensive study and experimentation in recent decades since it is responsible for the outcome of several clinical entities, such as major hepatic resections and liver transplantation. In addition to the organ's post reperfusion injury, this syndrome appears to play a central role in the dysfunction of distant tissues and systems. Thus, continuous research should be directed toward finding effective therapeutic options to improve the outcome and reduce the postoperative morbidity and mortality rates. Treprostinil is a synthetic analog of prostaglandin I2, and its experimental administration has shown encouraging results. It has already been approved by the Food and Drug Administration in the United States for pulmonary arterial hypertension and has been used in liver transplantation, where preliminary encouraging results showed its safety and feasibility by using continuous intravenous administration at a dose of 5 ng/kg/min. Treprostinil improves renal and hepatic function, diminishes hepatic oxidative stress and lipid peroxidation, reduces hepatictoll-like receptor 9 and inflammation, inhibits hepatic apoptosis and restores hepatic adenosine triphosphate (ATP) levels and ATP synthases, which is necessary for functional maintenance of mitochondria. Treprostinil exhibits vasodilatory properties and antiplatelet activity and regulates proinflammatory cytokines; therefore, it can potentially minimize ischemia-reperfusion injury. Additionally, it may have beneficial effects on cardiovascular parameters, and much current research interest is concentrated on this compound.

Association of High-Sensitivity Cardiac Troponin T With 30-Day and 5-Year Mortality After Cardiac Surgery

BACKGROUND

The relevance of perioperative myocardial injury (PMI) after cardiac surgery for 30-day mortality and long-term survival remains to be determined.

OBJECTIVES

This study assessed the association of PMI after cardiac surgery, reflected by postoperative troponin release, with 30-day mortality and long-term survival after: 1) coronary artery bypass grafting (CABG); 2) isolated aortic valve replacement (AVR) surgery; and 3) all other cardiac surgeries.

METHODS

A consecutive cohort of 8,292 patients undergoing cardiac surgery with serial perioperative high-sensitivity cardiac troponin T (hs-cTnT) measurements was retrospectively analyzed. The relationship between postoperative hs-cTnT release and 30-day mortality or 5-year mortality was analyzed after adjustment with EuroSCORE II using a Cox proportional hazards model. hs-cTnT thresholds for 30-day and 5-year mortality were determined for isolated CABG (32.3%), AVR (14%), and other cardiac surgery (53.8%).

RESULTS

High postoperative hs-cTnT levels were associated with higher 30-day mortality but not 5-year mortality. In CABG, median peak concentration of postoperative hs-cTnT was 1,044 ng/L, in AVR it was 502 ng/L, and in other cardiac surgery it was 1,110 ng/L. hs-cTnT thresholds defining mortality-associated PMI were as follows: for CABG, 2,385 ng/L (170× the upper reference limit of normal in a seemingly healthy population [URL]); for AVR, 568 ng/L (41× URL); and for other cardiac procedures, 1,873 ng/L (134× URL). hs-cTnT levels above the cutoffs resulted in an HR for 30-day mortality for CABG of 12.56 (P < 0.001), for AVR of 4.44 (P = 0.004), and for other cardiac surgery of 3.97 (P < 0.001).

CONCLUSIONS

PMI reflected by perioperative hs-cTnT release is associated with the expected 30-day mortality but not 5-year mortality. Postoperative hs-cTnT cutoffs to identify survival-relevant PMI are higher than suggested in current definitions.

Role of Biomarkers in the Management of Immune-Checkpoint Inhibitor-Related Myocarditis

PURPOSE OF REVIEW

Immune checkpoint inhibitor (ICI)-related myocarditis poses a major clinical challenge given its non-specific presentation, rapid progression, and high mortality rate. Here, we review the role of blood-based biomarkers in the clinical management of patients with ICI-related myocarditis.

RECENT FINDINGS

Myocardial injury, its unique pattern, and the co-occurrence with myositis are defining features of ICI-related myocarditis. Non-cardiac biomarkers, specifically creatinine phosphokinase, precedes the symptomatic presentation and is highly sensitive for diagnosing ICI-related myocarditis, making them useful screening biomarkers. Combined elevations in cardiac troponins and non-cardiac biomarkers improve the confidence of an ICI myocarditis diagnosis. High troponin and creatinine phosphokinase levels are strongly associated with severe outcomes. We propose biomarker-based algorithms for the monitoring and diagnosis of ICI-related myocarditis. Biomarkers, such as cardiac troponins and creatine phosphokinase, can be used in combination in the monitoring, diagnosis, and prognostication of patients with ICI-related myocarditis.

Biomarkers in 5q-associated spinal muscular atrophy-a narrative review

5q-associated spinal muscular atrophy (SMA) is a rare genetic disease caused by mutations in the SMN1 gene, resulting in a loss of functional SMN protein and consecutive degeneration of motor neurons in the ventral horn. The disease is clinically characterized by proximal paralysis and secondary skeletal muscle atrophy. New disease-modifying drugs driving SMN gene expression have been developed in the past decade and have revolutionized SMA treatment. The rise of treatment options led to a concomitant need of biomarkers for therapeutic guidance and an improved disease monitoring. Intensive efforts have been undertaken to develop suitable markers, and numerous candidate biomarkers for diagnostic, prognostic, and predictive values have been identified. The most promising markers include appliance-based measures such as electrophysiological and imaging-based indices as well as molecular markers including SMN-related proteins and markers of neurodegeneration and skeletal muscle integrity. However, none of the proposed biomarkers have been validated for the clinical routine yet. In this narrative review, we discuss the most promising candidate biomarkers for SMA and expand the discussion by addressing the largely unfolded potential of muscle integrity markers, especially in the context of upcoming muscle-targeting therapies. While the discussed candidate biomarkers hold potential as either diagnostic (e.g., SMN-related biomarkers), prognostic (e.g., markers of neurodegeneration, imaging-based markers), predictive (e.g., electrophysiological markers) or response markers (e.g., muscle integrity markers), no single measure seems to be suitable to cover all biomarker categories. Hence, a combination of different biomarkers and clinical assessments appears to be the most expedient solution at the time.

Troponin I as an Independent Biomarker of Outcome in Children with Systemic Inflammatory Response

Cardiac troponin-I (cTnI) is a biomarker of myocardial injury with implications for clinical outcomes. May other contributing factors that could affect outcomes have not been uniformly considered in pediatric studies. We hypothesized that there is an association between admission serum cTnI and outcomes in critically ill children taking into account the magnitude of the acute systemic inflammatory response syndrome (SIRS), serum lactate concentrations, and nutritional status. Second, we tested for potential factors associated with elevated serum cTnI. This was a prospective cohort study in 104 children (median age: 21.3 months) consecutively admitted to a pediatric intensive care unit (PICU) of a teaching hospital with SIRS and without previous chronic diseases. Primary outcome variables were PICU-free days, ventilator-free days, and 30-day mortality. Exposure variables were serum cTnI concentration on admission, revised pediatric index of mortality (PIM2), pediatric logistic organ dysfunction (PELOD-2), hypotensive shock, C-reactive protein, procalcitonin, and serum lactate on admission, and malnutrition. Elevated cTnI (>0.01 μg/L) was observed in 24% of patients, which was associated with the reduction of ventilator-free days (β coefficient = - 4.97; 95% confidence interval [CI]: -8.03; -1.91) and PICU-free days (β coefficient = - 5.76; 95% CI: -8.97; -2.55). All patients who died had elevated serum cTnI. The increase of 0.1 μg/L in cTnI concentration resulted in an elevation of 2 points in the oxygenation index (β coefficient = 2.0; 95% CI: 1.22; 2.78, p  < 0.001). The PIM2 score, hypotensive shock in the first 24 hours, and serum lactate were independently associated with elevated cTnI on admission. We conclude that elevated serum cTnI on admission is independently associated with adverse outcomes in children with SIRS and without associated chronic diseases.

Toxoplasma gondii Reactivation Aggravating Cardiac Function Impairment in Mice

BACKGROUND

Toxoplasma gondii (T. gondii) reactivation is common, especially among immunocompromised individuals, such as AIDS patients. The cardiac involvement associated with toxoplasmosis, however, is usually obscured by neurological deterioration. The aim of this study was to observe the alterations in cardiac functions in various landmark periods after infection and to assess whether reactivation more seriously damages the heart.

METHODS

We established three infection models in mice using TgCtwh6, a major strain of T. gondii prevalent in China. The groups included an acute group, chronic latent group, and reactivation group. We evaluated the cardiac function impairment via H & E staining, Masson staining, echocardiography, myocardial enzyme profiles, and cardiac troponin, and detected the expression of inflammatory factors and antioxidant factors with Western blotting. Immunofluorescence was used to detect the expression of the macrophage marker F4/80.

RESULTS

Our results showed that damage to the heart occurred in the acute and reactivation groups. Impaired cardiac function manifested as a decrease in heart rate and a compensatory increase in left ventricular systolic function. Serum levels of cardiac enzymes also increased dramatically. In the chronic phase, myocardial fibrosis developed, diastolic functions became severely impaired, inflammation persisted, and macrophage expression was slightly reduced. Ultimately, reactivation infection exacerbated damage to cardiac function in mice, potentially leading to diastolic heart failure. Macrophages were strongly activated, and myocardial fibrosis was increased. In addition, the antioxidant capacity of the heart was severely affected by the infection.

CONCLUSIONS

Taken together, these results suggested that the reactivation of T. gondii infection could aggravate injury to the heart, which could be associated with a host-cell-mediated immune response and strong cytokine production by macrophages, thus representing a novel insight into the pathogenic mechanism of toxoplasmosis.

Prospects for Precision Medicine in Acute Myocardial Infarction: Patient-Level Insights into Myocardial Injury and Repair

The past decade has seen a marked expansion in the understanding of the pathobiology of acute myocardial infarction and the systemic inflammatory response that it elicits. At the same time, a portfolio of tools has emerged to characterise some of these processes in vivo. However, in clinical practice, key decision making still largely relies on assessment built around the timing of the onset of chest pain, features on electrocardiograms and measurements of plasma troponin. Better understanding the heterogeneity of myocardial injury and patient-level responses should provide new opportunities for diagnostic stratification to enable the delivery of more rational therapies. Characterisation of the myocardium using emerging imaging techniques such as the T1, T2 and T2* mapping techniques can provide enhanced assessments of myocardial statuses. Physiological measures, which include microcirculatory resistance and coronary flow reserve, have been shown to predict outcomes in AMI and can be used to inform treatment selection. Functionally informative blood biomarkers, including cellular transcriptomics; microRNAs; extracellular vesicle analyses and soluble markers, all give insights into the nature and timing of the innate immune response and its regulation in acute MI. The integration of these and other emerging tools will be key to developing a fuller understanding of the patient-level processes of myocardial injury and repair and should fuel new possibilities for rational therapeutic intervention.

Structure and dynamics of endogenous protein complexes in human heart tissue captured by native nanoproteomics

Protein complexes are highly dynamic entities that display substantial diversity in their assembly, post-translational modifications, and non-covalent interactions, allowing them to play critical roles in various biological processes. The heterogeneity, dynamic nature, and low abundance of protein complexes in their native states present tremendous challenges to study using conventional structural biology techniques. Here we develop a "native nanoproteomics" strategy for the native enrichment and subsequent native top-down mass spectrometry (nTDMS) of low-abundance protein complexes. Specifically, we demonstrate the first comprehensive characterization of the structure and dynamics of cardiac troponin (cTn) complexes directly from human heart tissue. The endogenous cTn complex is effectively enriched and purified using peptide-functionalized superparamagnetic nanoparticles under non-denaturing conditions to enable the isotopic resolution of cTn complexes, revealing their complex structure and assembly. Moreover, nTDMS elucidates the stoichiometry and composition of the heterotrimeric cTn complex, localizes Ca2+ binding domains (II-IV), defines cTn-Ca2+ binding dynamics, and provides high-resolution mapping of the proteoform landscape. This native nanoproteomics strategy opens a new paradigm for structural characterization of low-abundance native protein complexes.

Structure and dynamics of endogenous protein complexes in human heart tissue captured by native nanoproteomics

Protein complexes are highly dynamic entities that display substantial diversity in their assembly, post-translational modifications, and non-covalent interactions, allowing them to play critical roles in various biological processes. The heterogeneity, dynamic nature, and low abundance of protein complexes in their native states present tremendous challenges to study using conventional structural biology techniques. Here we develop a "native nanoproteomics" strategy for the native enrichment and subsequent native top-down mass spectrometry (nTDMS) of low-abundance protein complexes. Specifically, we demonstrate the first comprehensive characterization of the structure and dynamics of cardiac troponin (cTn) complexes directly from human heart tissue. The endogenous cTn complex is effectively enriched and purified using peptide-functionalized superparamagnetic nanoparticles under non-denaturing conditions to enable the isotopic resolution of cTn complexes, revealing their complex structure and assembly. Moreover, nTDMS elucidates the stoichiometry and composition of the heterotrimeric cTn complex, localizes Ca2+ binding domains (II-IV), defines cTn-Ca2+ binding dynamics, and provides high-resolution mapping of the proteoform landscape. This native nanoproteomics strategy opens a new paradigm for structural characterization of low-abundance native protein complexes.

Recent perspectives on the early expression immunohistochemical markers in post-mortem recognition of myocardial infarction

Acute Myocardial Infarction (AMI) refers to the death of heart tissue in the absence ofperfusion. It is one of the top causes of death globally, particularly in middle andhigher-age groups. However, for the pathologist, the post-mortem macroscopic andmicroscopic diagnosis of early AMI remains challenging. In the early acute stage ofAMI, no microscopic visible signs of tissue alterations like necrosis and neutrophilinfiltration can be seen. In such a scenario, immunohistochemistry (IHC) accounts forthe most suitable and safest alternative to study early diagnostic cases by selectivelydetecting changes in the cell population. This systematic review focuses on themultiple causes/changes that lead to the privation of blood flow as well as tissuechanges induced by the absence of perfusion.We performed a systematic review of the last 10-15 years' publications that focused ondetecting immunohistochemical changes that appear in the cell population in case ofacute myocardial infarction. We found around 160 articles on AMI, which we narroweddown to 50 with the use of specific filters such as: "Acute Myocardial Infarction," "Ischemia," "Hypoxia," "Forensic," "Immunohistochemistry, and "Autopsy." The presentreview comprehensively highlights the current knowledge of specific IHC markers usedas gold standards during post-mortem investigation of acute myocardial infarction. Thepresent review comprehensively highlights the current knowledge of specific IHCmarkers used as gold standards during post-mortem investigation of acute myocardialinfarction, and some new potential immunohistochemical markers that can be used inthe early detection of myocardial infarction.

Pharmacological potential of new metronidazole/eugenol/dihydroeugenol hybrids against Trypanosoma cruzi in vitro and in vivo

AIMS

From well-delimited immunomodulatory, redox and antimicrobial properties; metronidazole and eugenol were used as structural platforms to assembly two new molecular hybrids (AD06 and AD07), whose therapeutic relevance was analyzed on T. cruzi infection in vitro and in vivo.

METHODS

Non-infected, T. cruzi-infected H9c2 cardiomyocytes, and mice non-treated and treated with vehicle, benznidazole (Bz - reference drug), AD06 and AD07 were investigated. Parasitological, prooxidant, antioxidant, microstructural, immunological, and hepatic function markers were analyzed.

RESULTS

Our findings indicated that in addition to having a direct antiparasitic effect on T. cruzi, metronidazole/eugenol hybrids (especially AD07) attenuated cellular parasitism, reactive species biosynthesis and oxidative stress in infected cardiomyocytes in vitro. Although AD06 and AD07 exerted no relevant impact on antioxidant enzymes activity (CAT, SOD, GR and GPx) in host cells, these drugs (especially AD07) attenuated trypanothione reductase activity in T. cruzi, which increased parasite's susceptibility to in vitro pro-oxidant challenge. AD06 and AD07 were well tolerated and do not determine humoral response suppression, mortality (100 % survival) or hepatotoxicity in mice, as indicated by transaminases plasma levels. AD07 also induced relevant in vivo antiparasitic and cardioprotective effects, attenuating parasitemia, cardiac parasite load and myocarditis in T. cruzi-infected mice. Although this cardioprotective response is potentially related to AD07 antiparasitic effect, a direct anti-inflammatory potential of this molecular hybrid cannot be ruled out.

CONCLUSION

Taken together, our findings indicated that the new molecular hybrid AD07 stood out as a potentially relevant candidate for the development of new, safe and more effective drug regimens for T. cruzi infection treatment.

Non-invasive electrochemical immunosensor for reverse iontophoretic determination of cardiac troponins (cTnT & cTnI) in a simulated artificial skin model. Significance of raw DPV and CV data for chemometric discrimination

Electrochemical immunosensors coupled with reverse iontophoresis (RI) for noninvasive determination of cardiac troponins were developed and validated according to ICH Q2 (R1) guideline. Linearity was in 0.01-10 and 100-500 ng/mL ranges. LODs (ng/mL) were in 6-25 × 10-4, while LOQs (μg/mL) were in 18-7.5 × 10-4 range. Chemometric evaluation was performed on raw data simply by principle component analysis and cluster analysis to discriminate stages of immunosensors. This is the first demonstration of RI determination of cardiac troponins so far. Findings of the current manuscript have great potential to develop point of care diagnostic systems for major cardiac events, where high sensitivity and specificity are required.

Are EPB41 and alpha-synuclein diagnostic biomarkers of sport-related concussion? Findings from the NCAA and Department of Defense CARE Consortium

BACKGROUND

Current protein biomarkers are only moderately predictive at identifying individuals with mild traumatic brain injury or concussion. Therefore, more accurate diagnostic markers are needed for sport-related concussion.

METHODS

This was a multicenter, prospective, case-control study of athletes who provided blood samples and were diagnosed with a concussion or were a matched non-concussed control within the National Collegiate Athletic Association-Department of Defense Concussion Assessment, Research, and Education Consortium conducted between 2015 and 2019. The blood was collected within 48 h of injury to identify protein abnormalities at the acute and subacute timepoints. Athletes with concussion were divided into 6 h post-injury (0-6 h post-injury) and after 6 h post-injury (7-48 h post-injury) groups. We applied a highly multiplexed proteomic technique that used a DNA aptamers assay to target 1305 proteins in plasma samples from athletes with and without sport-related concussion.

RESULTS

A total of 140 athletes with concussion (79.3% males; aged 18.71 ± 1.10 years, mean ± SD) and 21 non-concussed athletes (76.2% males; 19.14 ± 1.10 years) were included in this study. We identified 338 plasma proteins that significantly differed in abundance (319 upregulated and 19 downregulated) in concussed athletes compared to non-concussed athletes. The top 20 most differentially abundant proteins discriminated concussed athletes from non-concussed athletes with an area under the curve (AUC) of 0.954 (95% confidence interval: 0.922‒0.986). Specifically, after 6 h of injury, the individual AUC of plasma erythrocyte membrane protein band 4.1 (EPB41) and alpha-synuclein (SNCA) were 0.956 and 0.875, respectively. The combination of EPB41 and SNCA provided the best AUC (1.000), which suggests this combination of candidate plasma biomarkers is the best for diagnosing concussion in athletes after 6 h of injury.

CONCLUSION

Our data suggest that proteomic profiling may provide novel diagnostic protein markers and that a combination of EPB41 and SNCA is the most predictive biomarker of concussion after 6 h of injury.

Association between Cardiovascular Response and Inflammatory Cytokines in Non-Small Cell Lung Cancer Patients

Cardiovascular disease is an essential comorbidity in patients with non-small cell lung cancer (NSCLC) and represents an independent risk factor for increased mortality. Therefore, careful monitoring of cardiovascular disease is crucial in the healthcare of NSCLC patients. Inflammatory factors have previously been associated with myocardial damage in NSCLC patients, but it remains unclear whether serum inflammatory factors can be utilized to assess the cardiovascular health status in NSCLC patients. A total of 118 NSCLC patients were enrolled in this cross-sectional study, and their baseline data were collected through a hospital electronic medical record system. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of leukemia inhibitory factor (LIF), interleukin (IL)-18, IL-1β, transforming growth factor-β1 (TGF-β1), and connective tissue growth factor (CTGF). Statistical analysis was performed using the SPSS software. Multivariate and ordinal logistic regression models were constructed. The data revealed an increased serum level of LIF in the group using tyrosine kinase inhibitor (TKI)-targeted drugs compared to non-users (p < 0.001). Furthermore, serum TGF-β1 (area under the curve, AUC: 0.616) and cardiac troponin T (cTnT) (AUC: 0.720) levels were clinically evaluated and found to be correlated with pre-clinical cardiovascular injury in NSCLC patients. Notably, the serum levels of cTnT and TGF-β1 were found to indicate the extent of pre-clinical cardiovascular injury in NSCLC patients. In conclusion, the results suggest that serum LIF, as well as TGFβ1 together with cTnT, are potential serum biomarkers for the assessment of cardiovascular status in NSCLC patients. These findings offer novel insights into the assessment of cardiovascular health and underscore the importance of monitoring cardiovascular health in the management of NSCLC patients.