Copper(II)-Tannic Acid@Cu with In Situ Grown Gold Nanoparticles as a Bifunctional Matrix for Facile Construction of Label-Free and Ultrasensitive Electrochemical cTnI Immunosensor

Sensitive detection of cardiac troponin I (cTnI) is of great significance in the diagnosis of a fatal acute myocardial infarction. A redox-active nanocomposite of copper(II)-tannic acid@Cu (CuTA@Cu) was herein prepared on the surface of a glassy carbon electrode by electrochemical deposition of metallic copper combined with a metal stripping strategy. Then, HAuCl4 was in situ reduced to gold nanoparticles (AuNPs) by strong reductive catechol groups in the TA ligand. The AuNPs/CuTA@Cu composite was further utilized as a bifunctional matrix for the immobilization of the cTnI antibody (anti-cTnI), producing an electrochemical immunosensor. Electrochemical tests show that the immunoreaction between anti-cTnI and target cTnI can cause a significant reduction of the electrochemical signal of CuTA@Cu. It can be attributed to the insulating characteristic of the immunocomplex and its barrier effect to the electrolyte ion diffusion. From the signal changes of CuTA@Cu, cTnI can be analyzed in a wide range from 10 fg mL-1 to 10 ng mL-1, with an ultralow detection limit of 0.65 fg mL-1. The spiked recovery assays show that the immunosensor is reliable for cTnI determination in human serum samples, demonstrating its promising application in the early clinical diagnosis of myocardial infarction.

Contributing role of metabolic genes APOE, FTO, and LPL in the development of atrial fibrillation: insights from a case-control study

OBJECTIVE

The aim of the study was to examine the expression profile of genes (APOE, FTO, and LPL) associated with metabolic syndrome (MetS) in subjects with concomitant atrial fibrillation (AF).

METHODS

A total of 690 subjects were categorized into control, AF without MetS, and AF with MetS.

RESULTS

The expression profiles of the APOE, FTO, and LPL genes were decreased in AF subjects and AF subjects with MetS as compared to the controls. In AF without the MetS group, an inverse relationship was found between the expression of the LPL gene with body mass index (BMI) and a positive relationship with creatine kinase-MB, whereas expression of the FTO gene was inversely associated with fasting blood glucose and positively with cardiac troponin I in AF suffering from MetS. Expression of the LPL gene was directly linked with systolic blood pressure (SBP) and high-density lipoprotein-cholesterol (HDL-C), whereas an inverse correlation with heart rate and expression of the FTO gene in AF with MetS were shown. The expression of the LPL gene was inversely related to BMI in subjects with AF. The expression of the LPL gene was positively correlated with SBP and HDL-C and negatively correlated with heart rate, while the expression of the FTO gene was an important predictor of AF with MetS.

CONCLUSION

The decreased expression of APOE, FTO, and LPL genes in AF with and without MetS indicates their potential contributing role in the pathogenesis of AF.

Unveiling the role of long non-coding RNA MALAT1: a comprehensive review on myocardial infarction

Myocardial infarction (MI) stands at top global causes of death in developed countries, owing mostly to atherosclerotic plaque growth and endothelial injury-induced reduction in coronary blood flow. While early reperfusion techniques have improved outcomes, long-term treatment continues to be difficult. The function of lncRNAs extends to regulating gene expression in various conditions, both physiological and pathological, such as cardiovascular diseases. The objective of this research is to extensively evaluate the significance of the lncRNA called Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in the development and management of MI. According to research, MALAT1 is implicated in processes such as autophagy, apoptosis, cell proliferation, and inflammation in the cardiovascular system. This investigation examines recent research examining the effects of MALAT1 on heart function and its potential as a mean of diagnosis and treatment for post- MI complications and ischemic reperfusion injury.

The ABC-Stroke Risk Score and Effects of Atrial Fibrillation Screening on Stroke Prevention: Results From the Randomized LOOP Study

BACKGROUND

The ABC-stroke score is a risk scheme for prediction of stroke or systemic embolism (SE) in atrial fibrillation (AF). This study sought to examine whether the score could be useful in predicting stroke in AF-naïve individuals and risk stratifying for AF screening.

METHODS AND RESULTS

The LOOP (Atrial Fibrillation Detected by Continuous ECG Monitoring Using Implantable Loop Recorder to Prevent Stroke in High-Risk Individuals) study randomized 6004 AF-naïve individuals aged 70 to 90 years with stroke risk factors to either screening with an implantable loop recorder and anticoagulation upon detection of new-onset AF episodes ≥6 minutes, or usual care. A total of 5781 participants had available ABC-stroke score at baseline and were included in this secondary analysis: 4170 (72.1%) with an estimated stroke/SE risk ≤1%/year versus 1611 (27.9%) with an estimated stroke/SE risk >1%/year. Having an annual ABC-stroke risk >1% was associated with stroke/SE, stroke/SE/cardiovascular death, and all-cause death (hazard ratio, 1.82 [95% CI, 1.44-2.21], 2.17 [95% CI, 1.80-2.62], and 2.19 [95% CI, 1.87-2.56], respectively). For screening with implantable loop recorder versus usual care, no significant reduction in these study outcomes was obtained in any ABC-stroke risk groups (P>0.0500 for all), with no signal toward interaction (Pinteraction>0.2500 for all). Similar findings were yielded when assessing the ABC-stroke score as a continuous variable.

CONCLUSIONS

In an elderly, AF-naïve population with additional stroke risk factors, a higher ABC-stroke score could identify individuals with increased stroke risk. However, this risk score may not be useful in pinpointing those more likely to benefit from AF screening and subsequent preventive treatment. These findings should be considered as hypothesis generating and warrant further study.

REGISTRATION

URL: https://www.clinicaltrials.gov; unique identifier: NCT02036450.

Association of high-sensitivity cardiac troponin T with all-cause and cardiovascular mortality in older adults with low lean mass: A 14.6-year longitudinal study

BACKGROUND

Current evidence on the association between high-sensitivity cardiac troponin T (hs-cTnT) levels and mortality in elderly sarcopenic patients is limited. This study aimed to investigate the association of serum hs-cTnT concentrations with all-cause and cardiovascular mortality in older adults with low lean mass (LLM) and without baseline cardiovascular disease.

METHODS

This prospective cohort study included 369 older adults (representing 3.2 million people) from the National Health and Nutrition Examination Survey 1999-2004. Individuals were linked to national death records until 31 December 2019. The weighted Kaplan-Meier analysis, Cox proportional hazards models, restricted cubic spline models, stratified analysis, interaction analysis, and sensitivity analysis were performed to examine the association between hs-cTnT levels and mortality in older adults with LLM.

RESULTS

During 4697 person-years of follow-up (median duration, 14.6 years), 228 (65.6%) deaths were documented, including 56 (15.8%) deaths from cardiovascular disease. Individuals with a hs-cTnT level of ≥14 ng/L had 2.1- and 4.4-fold higher risks of all-cause and cardiovascular mortality, respectively. Compared with the lowest quartile, the fourth quartile of hs-cTnT levels was significantly associated with 3.1- and 6.4-fold higher risks of all-cause and cardiovascular mortality, respectively. Each one standard deviation increase in natural log-transformed hs-cTnT levels significantly and linearly increased the risks of all-cause and cardiovascular mortality by 39% and 61%, respectively. Stratified and sensitivity analyses confirmed the robustness of the association.

CONCLUSIONS

In this nationally representative cohort of US older adults with LLM, higher serum hs-cTnT concentrations were significantly associated with increased risks of all-cause and cardiovascular mortality.

Prognostic value of cardiac troponin in elderly patients with paroxysmal supraventricular tachycardia: A multicenter study

BACKGROUND

An elevated level of cardiac troponin I (cTnI) frequently accompanies an episode of supraventricular tachycardia (SVT). However, the predictive value of cTnI in elderly SVT patients has not been examined.

METHODS

We collected the electronic medical records of elderly SVT patients (over 65 years old) who visited four Taiwanese emergency departments over a 2-year period. The patients who underwent cTnI testing were included in the cohort and further categorized based on their cTnI results (positive or negative). The study's primary outcomes were the 5-year risks of major adverse cardiovascular events (MACE) and SVT recurrence.

RESULTS

One hundred and twenty-four patients met the inclusion criteria. Of these patients, 39 (31.5%) had a positive cTnI result, and 85 (68.5%) had a negative cTnI result. Patients with a positive cTnI result were older (p = 0.029) and had a longer hospital stay (p = 0.023) than those with a negative cTnI result. Multivariate analysis showed that age > 75 years (OR = 2.41; 95% CI 1.07-5.45; p = 0.034) was an independent predictor for cTnI elevation. In the survival analysis, no difference in the incidence of five-year MACE (p = 0.656) was observed between the cTnI-positive and cTnI-negative groups. Multivariate analysis revealed that a history of coronary artery disease was the only significant independent risk factor for MACE (HR = 4.30; 95% 95% CI 1.41-13.05; p = 0.010). For SVT recurrence, the multivariate analysis revealed that previous SVT (HR = 3.37; 95% CI 1.53-7.39; p = 0.002), smoking history (HR = 2.32; 95% CI 1.03-5.24; p = 0.043), and RFA treatment (HR = 0.20; 95% CI 0.06-0.65; p = 0.008) were significant independent predictors.

CONCLUSIONS

An increased cardiac troponin level may not effectively indicate the risk of MACE in elderly SVT patients. Physicians might want to be cautious when interpreting troponin test results for this specific patient group.

Low troponin I levels predict the presence of arrhythmia-induced cardiomyopathy in patients with atrial fibrillation and left ventricular systolic dysfunction

Successful atrial fibrillation (AF) ablation can improve reduced left ventricular ejection fraction (LVEF) with AF, which is defined as arrhythmia-induced cardiomyopathy (AIC). However, it is difficult to pre-procedurally predict the presence of AIC. We aimed to explore the pre-procedural predictors of AIC in patients with AF and reduced LVEF. This study included 60 patients with a reduced LVEF (LVEF < 50%; 69.1 ± 8.8 years; 45 men) who underwent successful AF ablation. Responders were defined as patients whose LVEF post-procedurally improved to the normal range (≥ 50%). Multivariate analysis revealed that the log-transformed pre-procedural troponin I (TnI) levels (odds ratio [OR] = 0.059; 95% confidence interval [CI] = 0.0052-0.42, p = 0.003) and age (OR = 0.91; 95% CI = 0.82-1.00, p = 0.044) were independent predictors of post-procedural LVEF recovery; further, low TnI levels (< 11.1 pg/ml) predicted LVEF recovery (sensitivity, 79.1%; specificity, 76.5%; positive predictive value, 89.5%; and negative predictive value, 59.1%). There were no significant differences in TnI levels between the baseline and 1 month after the procedure. However, four patients with high baseline TnI levels showed a > 50% reduction in the TnI levels post-procedurally, with three of these patients showing LVEF recovery. Low pre-procedural TnI levels can predict LVEF recovery after successful AF ablation in patients with reduced LVEF.

Label-Free, Portable, and Color-Indicating Cholesteric Liquid Crystal Test Kit for Acute Myocardial Infarction by Spectral Analysis and Naked-Eye Observation

The early diagnosis of acute myocardial infarction is difficult in patients with nondiagnostic characteristics. Acute myocardial infarction with chest pain is associated with increased mortality. This study developed a portable test kit based on cholesteric liquid crystals (CLCs) for the rapid detection of AMI through eye observation at home. The test kit was established on dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride-coated substrates covered by a CLC-binding antibody. Cardiac troponin I (cTnI) is a major biomarker of myocardial cellular injury in human blood. The data showed that the concentration of cTnI was related to light transmittance in a positive way. The proposed CLC test kit can be operated with a smartphone; therefore, it has high potential for use as a point-of-care device for home testing. Moreover, the CLC test kit is an effective and innovative device for the rapid testing of acute myocardial infarction-related diseases through eye observation, spectrometer, or even smartphone applications.

The Predictive Power of the 14-51 Ng/L High Sensitive Troponin T (hsTnT) Values for Predicting Cardiac Revascularization in a Clinical Setting

Background: high sensitive Troponin T (hsTnT) values between 14−50 ng/L represent a challenge in diagnosing acute coronary syndrome (ACS) at the Emergency Department (ED). The European Society for Cardiology (ESC) recommends a second hsTnT measurement 3 h later to distinguish between ACS and other causes depending on the Δ hsTnT. Our study aims to evaluate the predictive power this approach in a clinical setting by following patients presenting at the ED with hsTnT values 14−51 ng/L. Materials and methods: patients presenting with chest pain or dyspnea and a hsTnT value between 14 and 50 ng/L at the Erasmus MC ED in 2012−2013 were included and retrospectively monitored for 90 days after initial presentation for the occurrence of a cardiac revascularization. Patient records were reviewed according to the standing protocol, which depended on the Δ hsTnT. The “event-group” consists of patients receiving cardiac revascularization within 90 days after the ED visit, whereas the “no event-group” consisted of patients without revascularization. Results: a total of 889 patients patient records were reviewed. After excluding out-of-hospital-cardia-arrests (60), non-cardiological chest pain (373) and incomplete follow-up (100), 356 patients remained for final analysis. In 207 patients, a second hsTnT was actually performed (58%). From these 207 patients, 68 (33%) had a Δ hsTnT ≥7 ng/L. In these patients, 37 (54%) experienced an event within 90 days. In the 139 patients with a Δ hsTnT < 7 ng/L, 23 (17%) presented with an event within 90 days. Conclusion: our study demonstrated a sensitivity of 62%, a specificity of 79%, a positive predicted value (PPV) of 54% and a negative predictive value (NPV) of 83% for using a 3-h Δ hsTnT ≥7 ng/L cut-off, related to risk of an event in 90 days following ED presentation.

Smartphone and home-based liquid crystal sensor for rapid screening of acute myocardial infarction by naked-eye observation and image analysis

An early diagnosis of acute myocardial infarction (AMI) or thrombosis is complicated in patients with non-diagnostic features. AMI or thrombosis patients with chest pain are unintentionally discharged and have increased mortality. The study aimed to develop a smartphone biomedical sensor as a rapid test for AMI or thrombosis by naked-eye observation. The system was built on dimethyloctadecyl [3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP)-coated glass substrates, which refers to a nematic liquid crystal (LC)-binding antibody. One of the main biomolecules, cardiac troponin I (cTnI), is a substance in blood in people whose bodies are vulnerable to suffering a myocardial infarction or thrombosis. The other medium, LC, is a sensing biomaterial as an earlier detection method of ameliorating the disadvantages of older methods. Results revealed that the density of cTnI was positively correlated with the coefficient of light transmittance, and it has a high chance of being developed as a point-of-care device for a home inspection as it can be operated with a smartphone. As discussed above, the nematic LC is an effective and innovative healthcare method as a rapid test for diagnosis of AMI or thrombosis related diseases by naked-eye observation.

Biomarkers in the clinical management of patients with atrial fibrillation and heart failure

Atrial fibrillation (AF) and heart failure (HF) are two cardiovascular diseases with an increasing prevalence worldwide. These conditions share common pathophysiologiesand frequently co-exit. In fact, the occurrence of either condition can 'cause' the development of the other, creating a new patient group that demands different management strategies to that if they occur in isolation. Regardless of the temproral association of the two conditions, their presence is linked with adverse cardiovascular outcomes, increased rate of hospitalizations, and increased economic burden on healthcare systems. The use of low-cost, easily accessible and applicable biomarkers may hasten the correct diagnosis and the effective treatment of AF and HF. Both AF and HF effect multiple physiological pathways and thus a great number of biomarkers can be measured that potentially give the clinician important diagnostic and prognostic information. These will then guide patient centred therapeutic management. The current biomarkers that offer potential for guiding therapy, focus on the physiological pathways of miRNA, myocardial stretch and injury, oxidative stress, inflammation, fibrosis, coagulation and renal impairment. Each of these has different utility in current clinincal practice.

Cardiac troponin I measured with a very high sensitivity assay predicts subclinical carotid atherosclerosis: The Akershus Cardiac Examination 1950 Study

AIMS

Concentrations of cardiac troponin I (cTnI) are associated with incident ischemic stroke and predict the presence and severity of coronary atherosclerosis. Accordingly, we hypothesized that concentrations of cTnI measured with a very high sensitivity (hs-) assay would be associated with subclinical stages of carotid atherosclerosis in the general population.

METHODS

We measured hs-cTnI on the Singulex Clarity System in 1745 women and 1666 men participating in the prospective observational Akershus Cardiac Examination 1950 Study. All study participants were free from known coronary heart disease and underwent extensive cardiovascular phenotyping at baseline, including carotid ultrasound. We quantified carotid atherosclerosis by the carotid plaque score, carotid intima-media thickness (cIMT) and the presence of hypoechoic plaques.

RESULTS

Concentrations of hs-cTnI were measurable in 99.8% of study participants and were significantly associated with increased carotid plaque score (odds ratio for quartile 4 of hs-cTnI 1.59, 95% CI 1.22 to 2.07, p for trend < 0.001) and cIMT (odds ratio for quartile 4 of hs-cTnI 1.57, 95% CI 1.02 to 2.42, p for trend = 0.036), but not with the presence of hypoechoic plaques. hs-cTnI concentrations significantly improved reclassification and discrimination models in predicting carotid plaques when added to cardiovascular risk factors, no improvements were evident in predicting cIMT or hypoechoic plaques.

CONCLUSION

Concentrations of cTnI measured with a very high sensitivity assay are predictive of carotid atherosclerotic burden, a phenomenon likely attributable to common risk factors of subclinical myocardial injury, coronary and carotid atherosclerosis.

Risk-Based Approach for the Prediction and Prevention of Heart Failure

Targeted prevention of heart failure (HF) remains a critical need given the high prevalence of HF morbidity and mortality. Similar to risk-based prevention of atherosclerotic cardiovascular disease, optimal HF prevention strategies should include quantification of risk in the individual patient. In this review, we discuss incorporation of a quantitative risk-based approach into the existing HF staging landscape and the clinical opportunity that exists to translate available data on risk estimation to help guide personalized decision making. We first summarize the recent development of key HF risk prediction tools that can be applied broadly at a population level to estimate risk of incident HF. Next, we provide an in-depth description of the clinical utility of biomarkers to personalize risk estimation in select patients at the highest risk of developing HF. We also discuss integration of genomics-enhanced approaches (eg, Titin [TTN]) and other risk-enhancing features to reclassify risk with a precision medicine approach to HF prevention. Although sequential testing is very likely to identify low and high-risk individuals with excellent accuracy, whether or not interventions based on these risk models prevent HF in clinical practice requires prompt attention including randomized placebo-controlled trials of candidate therapies in risk-enriched populations. We conclude with a summary of unanswered questions and gaps in evidence that must be addressed to move the field of HF risk assessment forward.

Prognostic Value of Troponin in Patients with Atrial Fibrillation Admitted to an Emergency Department: Review and Meta-Analysis

Introduction

Elevated levels of cardiac troponin (cTn) indicate underlying heart disease and is known to predict adverse events in multiple conditions. Its role in atrial fibrillation (AF) in the acute setting is still not conclusive. We aimed to assess the prognostic value of c-Tn in patients with AF admitted to an emergency department (ED).

Methods

Systematic searches were conducted using PubMed and the Cochrane Library and the International Clinical Trials Registry Platform to identify studies from year 2009 to October 2019 reporting on the prognostic value of cTn on all-cause mortality or major adverse cardiac events (MACE) in adult patients with AF in the ED. We pooled hazard ratio (HR) and 95% confidence interval (CI) using fixed and random effects models according the heterogeneity. We planned to conduct a sensitivity and subgroup analyses.

Results

Five studies involving 5750 patients were identified. The mean follow-up ranged from 12 to 35 months. An increase in mortality was observed in the elevated cTn group compared to the controls, HR=2.7 (95% CI 1.55-4.72), P for effect<0.001, I2=80%). For MACE, the pooled HR was 2.17 (95%CI 1.60-2.94), P for effect<0.001, I2=0%). In the subgroup analysis we found no significant difference in type of troponin used and study design.

Conclusions

The elevation of cardiac troponin was significantly associated with higher mortality and major adverse cardiac events in patients with AF admitted to an ED. In this setting the use of c-Tn could provide prognostic information.

Mortality at 5 Years Among Very Elderly Patients Undergoing High Sensitivity Troponin T Testing for Suspected Acute Coronary Syndromes

BACKGROUND

Patients aged ≥80 years old often present to Emergency Departments (ED) with symptoms potentially due to an acute coronary syndrome (ACS). This study aimed to evaluate associations between baseline level(s) of high sensitivity troponin T (HsTnT), adjudicated diagnoses and outcomes.

METHODS

Consecutive patients aged ≥80 years were studied, who presented to the ED at Liverpool Hospital, NSW, Australia during the 4 months period March to June 2014 (inclusive) with symptoms suggestive of an ACS, and who had at least one HsTnT assay performed. Diagnoses were based on the fourth universal definition of MI (myocardial infarction) including type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury; the rest were termed "other diagnoses". Patients were categorised by baseline HsTnT levels 1) ≤14 ng/L, 2) 15-29 ng/L, 3) 30-49 ng/L and 4) ≥50 ng/L.

RESULTS

Of 2,773 patients screened, 545 were aged ≥80 years (median age 85 [IQR 82-88]); median follow-up was 32 months (IQR 5-56). The respective rates of adjudicated diagnoses were type-I MI 3.1%, type-2 MI 13%, acute myocardial injury 9.5%, chronic myocardial injury 56% and 18.6% had other diagnoses. Mortality rates increased, irrespective of adjudicated diagnoses with increasing HsTnT levels (ng/L): 17% (16/96) for ≤14; 35% (67/194) for 15-29; 51% (65/127) for 30-49; and 64% (82/128) for ≥50 ng/L; log rank p≤0.001. On multi-variable analyses, after adjusting for potential confounding factors including age, hypertension, chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD), MI type was not associated with late mortality.

CONCLUSIONS

Among patients aged ≥80 years higher HsTnT levels, irrespective of adjudicated diagnoses, were associated with increased mortality. Most very elderly patients presenting with symptoms suggestive of an ACS undergoing HsTnT testing in EDs had elevated levels most commonly due to chronic myocardial injury. Whether any interventions can modify outcomes require prospective evaluation.

Soluble Urokinase-Type Plasminogen Activator Receptor and High-Sensitivity Troponin Levels Predict Outcomes in Nonobstructive Coronary Artery Disease

Background Multiple biomarkers have been independently and additively associated with major adverse cardiovascular events in patients with coronary artery disease. We investigated the prognostic value of suPAR (soluble urokinase-type plasminogen activator receptor) and hsTnI (high-sensitivity troponin I) levels in symptomatic patients with no obstructive coronary artery disease. We hypothesized that high levels of these biomarkers will be associated with the risk of future adverse outcomes. Methods and Results Plasma levels of suPAR and hsTnI were measured in 556 symptomatic patients with no obstructive coronary artery disease. A biomarker risk score was calculated by counting the number of biomarkers above the median in this cohort (suPAR>2523 pg/mL and hsTnI>2.7 pg/mL). Survival analyses were performed with models adjusted for traditional risk factors. All-cause death and major adverse cardiovascular events (cardiovascular death, myocardial infarction, stroke, and heart failure) served as clinical outcomes over a median follow-up of 6.2 years. Mean age was 57±10 years, 49% of the cohort patients were female, and 68% had a positive stress test. High suPAR and hsTnI levels were independent predictors of all-cause death (hazard ratio=3.2 [95% CI, 1.8-5.7] and 1.3 [95% CI, 1.0-1.7], respectively; both P<0.04) and major adverse cardiovascular events (hazard ratio=2.7 [95% CI, 1.4-5.4] and 1.5 [95% CI, 1.2-2.0], respectively; both P<0.002). Compared with a biomarker risk score of 0, biomarker risk scores of 1 and 2 were associated with 19- and 14-fold increased risk of death and development of major adverse cardiovascular events, respectively. Conclusions Among symptomatic patients with no obstructive coronary artery disease, higher levels of suPAR and hsTnI were independently and additively associated with an increased risk of adverse events. Whether modification of these biomarkers will improve risk in these patients needs further investigation.

Prognostic significance of troponin level in 3121 patients presenting with atrial fibrillation (The NIHR Health Informatics Collaborative TROP-AF study)

Background Patients presenting with atrial fibrillation (AF) often undergo a blood test to measure troponin, but interpretation of the result is impeded by uncertainty about its clinical importance. We investigated the relationship between troponin level, coronary angiography, and all-cause mortality in real-world patients presenting with AF. Methods and Results We used National Institute of Health Research Health Informatics Collaborative data to identify patients admitted between 2010 and 2017 at 5 tertiary centers in the United Kingdom with a primary diagnosis of AF. Peak troponin results were scaled as multiples of the upper limit of normal. A total of 3121 patients were included in the analysis. Over a median follow-up of 1462 (interquartile range, 929-1975) days, there were 586 deaths (18.8%). The adjusted hazard ratio for mortality associated with a positive troponin (value above upper limit of normal) was 1.20 (95% CI, 1.01-1.43; P<0.05). Higher troponin levels were associated with higher risk of mortality, reaching a maximum hazard ratio of 2.6 (95% CI, 1.9-3.4) at ≈250 multiples of the upper limit of normal. There was an exponential relationship between higher troponin levels and increased odds of coronary angiography. The mortality risk was 36% lower in patients undergoing coronary angiography than in those who did not (adjusted hazard ratio, 0.61; 95% CI, 0.42-0.89; P=0.01). Conclusions Increased troponin was associated with increased risk of mortality in patients presenting with AF. The lower hazard ratio in patients undergoing invasive management raises the possibility that the clinical importance of troponin release in AF may be mediated by coronary artery disease, which may be responsive to revascularization.

Preprocedural Troponin T Levels Predict the Improvement in the Left Ventricular Ejection Fraction After Catheter Ablation of Atrial Fibrillation/Flutter

Background

Left ventricular (LV) systolic dysfunction is reversible in some patients once the arrhythmia is controlled. However, identifying this arrhythmia‐induced cardiomyopathy among patients with LV systolic dysfunction is challenging. We explored the factors predicting the reversibility of the LV ejection fraction (LVEF) after catheter ablation of atrial fibrillation and/or atrial flutter in patients with LV systolic dysfunction.

Methods and Results

Forty patients with a reduced LVEF (LVEF <50%; 66.2±10.7 years; 32 men) who underwent atrial fibrillation/atrial flutter ablation were included. Transthoracic echocardiography was performed before and during the early (<4 days) and late phases (>3 months) after the ablation. Responders were defined as having a normalized LVEF (≥50%) during the late phase after the ablation. The LVEF improved from 39.8±8.8 to 50.9±10.9% at 1.2±0.6 days after the procedure, and to 56.2±12.2% at 9.6±8.0 months after the procedure (both for P<0.001). Thirty (75.0%) patients were responders. The preprocedural echocardiographic parameters were comparable between the responders and nonresponders. In the multivariate analysis, the preprocedural high‐sensitivity troponin T was the only independent predictor of the recovery of the LV dysfunction during the late phase after ablation (odds ratio, 1.17; 95% CI, 1.06–1.33; P=0.001), and a level of ≤12 pg/mL predicted recovery of the LV dysfunction with a high accuracy (sensitivity, 90.0%; specificity, 76.7%; positive predictive value, 56.3%; and negative predictive value, 95.8%).

Conclusions

Preprocedural high‐sensitivity troponin T levels might be a simple and useful parameter for predicting the reversibility of the LV systolic dysfunction after atrial fibrillation/atrial flutter ablation in patients with a reduced LVEF.

A liquid-crystal-based immunosensor for the detection of cardiac troponin I

Cardiac troponin I (cTnI) is one of the most sensitive and specific markers of myocardial cell injury. In this study, a label-free biosensor that utilizes the birefringence property of liquid crystal (LC) for the detection of cTnI is demonstrated.

High-sensitivity troponin I and B-type natriuretic peptide biomarkers for prediction of cardiovascular events in patients with coronary artery disease with and without diabetes mellitus

Background

High-sensitivity troponin I (hs-Tnl) and B-type natriuretic peptide (BNP) are promising prognostic markers for coronary artery disease (CAD). This prospective cohort study investigated whether a combination of these cardiac biomarkers with conventional risk factors would add incremental value for the prediction of secondary major adverse cardiovascular events (MACEs) in patients with CAD, with and without type 2 diabetes mellitus (T2DM).

Methods

Baseline plasma level of hs-Tnl and BNP was measured in 2275 Chinese patients with stable CAD. Patients were monitored for new-onset of MACE over a median of 51 months. Cox proportional hazard model and area under the receiver operating characteristic curve (AUC) were used to assess the association of cardiac biomarkers with MACE and their predictive values in relationship with or without T2DM.

Results

During the follow up period 402 (18%) patients experienced a new-onset MACE with hs-Tnl and BNP level significantly higher than in those without MACE. In multivariable analyses, patients with elevated hs-Tnl (hazard ratio, 1.75 [95% CI 1.41–2.17]; P < 0.001) and BNP (hazard ratio, 1.42 [95% CI 1.15–1.75]; P = 0.001) were significantly associated with an increased risk of MACE after adjustment for variables of a risk factor model of age, sex, T2DM and hypertension. The risk factor model had an AUC of 0.64 for MACE prediction. The AUC significantly increased to 0.68 by the addition of hs-Tnl to the risk factor model. Subgroup analyses showed that hs-Tnl and BNP remained significant predictors of MACE in both patients with and without T2DM in multivariable models with higher risk of MACE evident in those without T2DM. Among patients without T2DM, addition of each biomarker yielded greater predictive accuracy than in T2DM patients, with AUC further increased to 0.75 when a combination of hs-Tnl and BNP was added to the risk factor model (age, sex and hypertension).

Conclusions

Elevated hs-Tnl and BNP level are independent predictors of new-onset MACE in CAD patients, irrespective of diabetes status. Among CAD patients without T2DM, a combination of cardiac biomarkers hs-Tnl and BNP yield the greatest predictive value beyond conventional risk factors.

Troponin T Predicts Cardioembolic Aetiology and Clinical Outcome in Undetermined Ischaemic Stroke in Hyperacute Phase

BACKGROUND

Elevated high-sensitivity cardiac troponin T (hs-cTnT) levels have been related to clinical outcome in stroke patients. However, the role of hs-cTnT and its potential as a biomarker in ischaemic stroke (IS) has not been well established. This study aims to determine whether basal hs-cTnT determination in the hyperacute phase of undetermined IS and transient ischaemic attack (TIA) can predict the cardioembolic aetiology and clinical outcome.

METHODS

We prospectively studied 110 consecutive patients with undetermined acute IS and TIA. hs-cTnT levels were determined at hospital arrival. Large vessel stenosis/occlusion and previously known aetiologies at admission were exclusion criteria for this study. All patients were subjected to a complete aetiological evaluation. A 12-month follow-up was performed in all patients. The subtype of IS was evaluated following the SSS-TOAST criteria. We established two groups at admission: cardioembolic aetiology (group A) and noncardioembolic aetiologies (group B).

RESULTS

The number of patients in each group was similar (group A: 52, 47.27%; group B, 58, 52.73%). Patients in group A had elevated hs-cTnT more frequently (61.54% versus 17.24%; P < .001). Group A patients had significantly higher mortality at 3 months (14.29% versus 1.82%, P = .025). In the multivariate analysis, elevated hs-cTnT was the only independent predictor of cardioembolic aetiology (odds ratio: 14.821; 95% confidence interval: 3.717-59.102, P < .001).

CONCLUSION

Baseline hs-cTnT assessment in undetermined strokes and TIA during the hyperacute phase is independently associated with cardioembolic aetiology.

Identification of acute myocardial infarction in elderly patients using optimized highly sensitive troponin I thresholds

Purpose: Established diagnostic thresholds for high-sensitivity cardiac troponins (hs-cTn) might not apply for elderly patients as they are elevated irrespective of the presence of an acute myocardial infarction (AMI). Aim of the present study was to investigate hs-cTnI in elderly patients with suspected AMI and to calculate optimized diagnostic cutoffs. Material and methods: Data from a prospective multi-centre study and from a second independent prospective single-centre cohort study were analysed. A number of 2903 patients were eligible for further analysis. Patients > 70 years were classified as elderly. hs-cTnI was measured upon admission. Results: Around 34.7% of 2903 patients were classified as elderly. Around 22.5% of elderly patients were finally diagnosed with AMI. Elderly patients had higher hs-cTnI levels at admission irrespective of the final diagnosis (p < 0.001). According to the AUROC, hs-cTnI was a strong marker for detection of AMI in elderly patients. Application of the 99th percentile cutoffs showed a substantially lower specificity in elderly. By using optimized thresholds, specificity was improved to levels as in younger patients in both cohorts but accompanied with a decrease in sensitivity. Conclusions: hs-cTnI levels have a lower specificity for detecting AMI in elderly patients. This lower specificity can be improved by using hs-cTnI thresholds optimized for elderly patients.

Clinical determinants of plasma cardiac biomarkers in patients with stable chest pain

OBJECTIVE

Troponin and B-type natriuretic peptide (BNP) concentrations are associated with cardiovascular risk in stable patients. Understanding their determinants and identifying modifiable clinical targets may improve outcomes. We aimed to establish clinical and cardiac determinants of these biomarkers.

METHODS

This was a prespecified substudy from the randomised Scottish Computed Tomography of the Heart trial, which enrolled patients 18-75 years with suspected stable angina between 2010 and 2014 (NCT01149590). We included patients from six centres in whom high-sensitivity troponin I and BNP were measured (Singulex Erenna). Patients with troponin >99th centile upper reference limit (10.2 ng/L) or BNP ≥400 ng/L were excluded to avoid inclusion of patients with myocardial injury or heart failure. Multivariable linear regression models were constructed with troponin and BNP as dependent variables.

RESULTS

In total, 885 patients were included; 881 (99%) and 847 (96%) had troponin and BNP concentrations above the limit of detection, respectively. Participants had a slight male preponderance (n=513; 56.1%), and the median age was 59.0 (IQR 51.0-65.0) years. The median troponin and BNP concentrations were 1.4 (IQR 0.90-2.1) ng/L and 29.1 (IQR 14.0-54.0) ng/L, respectively. Age and atherosclerotic burden were independent predictors of both biomarkers. Male sex, left ventricular mass and systolic blood pressure were independent predictors of increased troponin. In contrast, female sex and left ventricular volume were independent predictors of increased BNP.

CONCLUSIONS

Troponin and BNP are associated with coronary atherosclerosis but have important sex differences and distinct and contrasting associations with CT-determined left ventricular mass and volume.

CLINICAL TRIAL REGISTRATION

NCT01149590; Post-results.

Clinical Features and Prognosis of Patients with Acute and Chronic Myocardial Injury Admitted to the Emergency Department

BACKGROUND

This study aimed to investigate the clinical features and prognosis of acute and chronic myocardial injury without clinical evidence of myocardial infarction in patients admitted to the emergency department.

METHODS

We analyzed the clinical data of all consecutive patients admitted to the emergency department during the years 2012 and 2013 who had at least 2 determinations of troponin I (TnI Ultra Siemens, Advia Centaur) and without a diagnosis of myocardial infarction. Clinical events were evaluated in a 3-year follow-up.

RESULTS

A total of 1201 patients met the study's inclusion criteria and were included in the analysis (833 with cTnI below the 99th percentile, 261 with acute myocardial injury, and 107 with chronic myocardial injury). During a median follow-up of more than 36 months, mortality and rehospitalization for heart failure were significantly higher in patients with acute or chronic myocardial injury compared with patients without myocardial injury. No differences were observed in overall mortality between patients with acute and chronic myocardial injury, or in the rate of readmission due to acute coronary syndrome. However, the risk of readmission due to heart failure (adjusted HR 2.17; 95% confidence interval, 1.26-3.75; P = .005) was higher in patients with chronic myocardial injury.

CONCLUSIONS

Mortality in long-term follow-up is high and similar in acute and chronic myocardial injury; however, the risk of readmission due to heart failure is higher in patients with chronic myocardial injury compared with patients with acute myocardial injury.

Biomarkers Associated with Stroke Risk in Atrial Fibrillation

Background:

Atrial fibrillation (AF) is associated with an increased risk of cardioembolic stroke. The risk of cardioembolism is not adequately reduced with the administration of oral anticoagulants, since a number of patients continue to experience thromboembolic events despite receiving treatment. Therefore, identification of a circulating biomarker to identify these high-risk patients would be clinically beneficial.

Objective:

In the present article, we aim to review the available data regarding use of biomarkers to predict cardioembolic stroke in patients with AF.

Methods:

We performed a thorough search of the literature in order to analyze the biomarkers identified thus far and critically evaluate their clinical significance.

Results:

A number of biomarkers have been proposed to predict cardioembolic stroke in patients with AF. Some of them are already used in the clinical practice, such as d-dimers, troponins and brain natriuretic peptide. Novel biomarkers, such as the inflammatory growth differentiation factor-15, appear to be promising, while the role of micro-RNAs and genetics appear to be useful as well. Even though these biomarkers are associated with an increased risk for thromboembolism, they cannot accurately predict future events. In light of this, the use of a scoring system, that would incorporate both circulating biomarkers and clinical factors, might be more useful.

Conclusions:

Recent research has disclosed several biomarkers as potential predictors of cardioembolic stroke in patients with AF. However, further research is required to establish a multifactorial scoring system that will identify patients at high-risk of thromboembolism, who would benefit from more intensive treatment and monitoring.

High-sensitivity troponin T and long-term adverse cardiac events among patients presenting with suspected acute coronary syndrome in Singapore

INTRODUCTION

Prognostic thresholds for 30-day major adverse cardiac events (MACE) have been studied for high-sensitivity troponin T (hsTnT) in patients with suspected acute coronary syndrome (ACS), but there is limited data on the prognostic performance of hsTnT for one-year MACE.

METHODS

We prospectively measured hsTnT (in ng/mL up to two decimal places) at 0, 2 and 7 hours for patients presenting with symptoms suggestive of ACS to our emergency department from March 2010 to April 2013. We assessed the prognostic performance of hsTnT cut-offs for 30-day and one-year MACE, and the utility of delta-hsTnT in predicting MACE.

RESULTS

Among 2,444 patients studied, 273 (11.2%) developed MACE (including index MACE) by 30 days and 359 (14.7%) patients developed MACE at one year. The suggested hsTnT cut-off for 30-day MACE was ≥ 10 ng/L at 0 hour (positive predictive value [PPV] 33.5%, negative predictive value [NPV] 94.5%) and 7 hours (PPV 37.3%, NPV 94.5%), and ≥ 20 ng/L at 2 hours (PPV 36.9%, NPV 96.9%). For one-year MACE, the suggested cut-off was also ≥ 10 ng/L at all readings. Plasma hsTnT ≥ 30 ng/L at any reading gave PPV > 54% and NPV > 93% for 30-day MACE. Absolute 0-2 hour and 2-7 hour delta-hsTnT ≥ 10 ng/L gave PPV > 50% for 30-day and one-year MACE.

CONCLUSION

Patients with 0-, 2- or 7-hour hsTnT ≥ 30 ng/L and 0-2 hour delta-hsTnT ≥ 10 ng/L had PPV > 50% for 30-day and one-year MACE, and should be investigated thoroughly.

High-sensitivity cardiac troponin T as an independent predictor of stroke in patients admitted to an emergency department with atrial fibrillation

AIMS

Elevated levels of high-sensitivity cardiac troponin T (hsTnT) are associated with adverse outcomes in numerous patient populations. Their value in prediction of stroke risk in patients with atrial fibrillation (AF) is in debate.

METHODS

The study population included 2898 consecutive patients presenting with AF to the emergency department of the Department of Cardiology, Heidelberg University Hospital. Associations between hsTnT and stroke risk were assessed using multivariable Cox regression.

RESULTS

Elevated hsTnT levels (>14 ng/L) were associated with increased risk of stroke. Even after adjustment for various risk factors, elevated hsTnT remained independently associated with stroke risk in patients with AF, adjusted hazard ratio 2.35 [95% confidence interval (CI): 1.26-4.36] (P = 0.007). These results were consistent across important subgroups (age, renal function, ejection fraction, CHA2DS2-VASc score and main admission diagnosis). For hsTnT, area under the receiver-operating-characteristic curve (AUC) was 0.659 [95% CI: 0.575-0.742], compared to 0.610 [95% CI: 0.526-0.694] for the CHA2DS2-VASc score. Inclusion of hsTnT in the multivariable model for stroke risk prediction consisting of all variables of the CHA2DS2-VASc score was associated with a significant improvement of its discriminatory power.

CONCLUSION

Elevated hsTnT levels are significantly associated with higher risk of stroke and provide prognostic information independent of CHA2DS2-VASc score variables. Measurement of hsTnT may improve prediction of stroke risk in patients presenting to an emergency department with AF as compared to risk stratification based only on clinical variables.

Prognostic value of cardiac troponin I assay in hospitalized elderly patients

BACKGROUND

Cardiac troponin I (cTnI) has been poorly studied in elderly inpatients.

AIM

This study wanted to assess factors influencing the increase in cTnI and its prognostic value in hospitalized elderly patients.

METHODS

354 elderly (mean age of 84.8 ± 6.9 years) patients consecutively admitted in the Geriatrics Division in Padua were tested for cTnI levels assay during the hospital stay. Number of subsequent patient deaths at 6 months and 2 years were registered.

RESULTS

Of the 354 patients, 27 (7.6%) died in hospital; their levels were not significantly higher or more frequently positive on cTnI than those of the remainder of the sample. 71 (20.01%) patients died within 6 months of being discharged, and in-hospital positive cTnI levels emerged as a mortality risk factor in this group [unadjusted HR 1.13 (1.04-1.23); p = 0.004]. At 2 years, a total of 174 patients (49.2%) had died, but in-hospital pathological cTnI levels were not a mortality risk factor in this group.

DISCUSSION

It should be noted that cTnI level was a risk factor for mortality at 6 months but no longer at 2 years after an elderly patient's hospitalization. This finding may relate to patients' limited physiological reserves or be driven by the fact that the elderly tend to receive fewer evidence-based treatments, and to be managed more conservatively than younger patients.

CONCLUSIONS

In the multidimensional analysis of older patients, troponin I can be used to stratify patients and assess mortality risk at 6 months, but not at 2 years.

Relation of Chronic Myocardial Injury and Non-ST-Segment Elevation Myocardial Infarction to Mortality

The prognosis in patients with chest pain and chronic myocardial injury compared with patients with non-ST-segment elevation myocardial infarction (NSTEMI) is unknown. This study aims to investigate differences in long-term outcomes. Patients with chest pain at Karolinska University Hospital, Sweden from 2011 to 2014, who had stable high-sensitivity cardiac troponin T (hs-cTnT) levels were compared with patients with NSTEMI. We estimated hazard ratios with 95% confidence intervals for the risk of all-cause mortality, myocardial infarction, and heart failure at different hs-cTnT levels using patients with NSTEMI as referent. A total of 20,387 patients were included, of whom 927 had NSTEMI. Among 19,460 patients with stable hs-cTnT levels, 1,528 had chronic myocardial injury defined as stable hs-cTnT levels > 14 ng/L. Mean follow-up was 3.2 years. Patients with hs-cTnT levels of <5 and 5 to 9 ng/L had a lower risk, while patients with chronic myocardial injury with hs-cTnT levels of 30 to 49 and ≥50 ng/L had a higher risk of death (adjusted hazard ratios, 95% confidence intervals: 1.65, 1.30 to 2.10 and 2.13, 1.60 to 2.84, respectively) compared with patients with NSTEMI. Patients with hs-cTnT levels <15 ng/L had a lower risk of heart failure, with no difference in risk at higher hs-cTnT levels. All stable hs-cTnT levels were associated with a lower risk of myocardial infarction (MI). In conclusion, patients with chest pain and stable hs-cTnT levels 10 to 29 ng/L have a similar risk, and those with chronic myocardial injury with hs-cTnT levels of ≥30 ng/L have an increased risk of long-term all-cause mortality compared with patients with NSTEMI.

Perioperative Cardiac Troponin I Levels in Patients Undergoing Total Hip and Total Knee Arthroplasty: A Single Center Study

Background

Cardiac injury is one of the significant perioperative complications in major orthopedic surgeries and its early diagnosis is useful in the reduction of postoperative comorbidity. The cardiac troponin is a sensitive and specific biomarker for detecting this damage.

Objectives

The aim of this study was to evaluate the levels of perioperative cardiac troponin I (cTnI) before and after arthroplasty in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). The effects of related variables and probable major cardiac complications were evaluated in this study.

Methods

For one year, in a prospective, cross-sectional study, the serum levels of cTnI before and 48 hours after arthroplasty were evaluated in 52 patients. Possible contributing factors including age, gender, body mass index (BMI), daily activity, history of hospitalization due to cardiovascular diseases, underlying illness, and medications were recorded. The Chi-square test, Pearson correlation, and Spearman test were used to examine the relationship between variables.

Results

The mean cTnI increased significantly after arthroplasty (P < 0.001). There was no significant relationship between age (P = 0.708), gender (P = 0.225), BMI (P = 0.195), daily activity (0.441), underlying illness (P = 0.244), and cTnI levels after arthroplasty. Linear regression showed BMI was significantly correlated with troponin changes (P = 0.006). Five patients had heart palpitations and one had chest pain, but none of the patients had any findings in favor of cardiac injury.

Conclusions

cTnI levels after THA and TKA increased significantly, but this elevation was in the normal range. In addition, none of them had a new cardiac complication after arthroplasty.

Cardiac biomarkers predict mortality in emergency patients presenting with atrial fibrillation

Objectives

To assess the predictive value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitive troponin T (hs-TnT) serum levels for mid-term mortality in patients presenting with symptomatic atrial fibrillation (AF) to an emergency department.

Methods

Non-interventional cohort/follow-up study, including consecutive patients presenting to a tertiary care university emergency department due to symptomatic AF between 2012 and 2016. Multivariable Cox proportional hazard regression models were used to estimate the mortality rates and hazards per 100 patient-years (pry) for NT-proBNP and hs-TnT serum levels in quintiles.

Results

2574 episodes of 1754 patients (age 68 (IQR 58–75) years, female gender 1199 (44%), CHA₂DS₂-VASc 3 (IQR 1–4)) were recorded. Following the exclusion of incomplete datasets, 1780 episodes were available for analysis. 162 patients deceased during the mid-term follow-up (median 23 (IQR 4–38) months); the mortality rate was 4.72/100 pry. Hazard for death increased with every quintile of NT-proBNP by 1.53 (HR; 95% CI 1.27 to 1.83; p<0.001) and by 1.31 (HR; 95% CI 1.10 to 1.55; p=0.002) with every quintile of hs-TnT in multivariate Cox-regression analysis. No interaction between NT-proBNP and hs-TnT levels could be observed.

Conclusion

Elevated NT-proBNP and hs-TnT levels are independently associated with increased mid-term mortality in patients presenting to an emergency department due to symptomatic AF.

Trial registration number

NCT03272620; Results.

Predictors of 10-year changes in levels of N-terminal pro B-type natriuretic peptide and cardiac troponin I in the elderly

BACKGROUND

Measurement of N-terminal pro B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) might be useful for monitoring of cardiovascular disease in the elderly. However, it is not clear whether changes in these biomarkers are associated with changes in the cardiovascular risk profile and if this pattern could be modified by changes in lifestyle habits or medications.

METHODS

We measured levels of NT-proBNP and cTnI in community-dwelling subjects (PIVUS study) upon visits scheduled at age 70 (n=1007), 75 (n=825) and 80 (n=602). The associations of these biomarkers with repeated measurements of clinical variables (risk factors, lifestyle habits, echocardiographic data and medications) were investigated using sex-adjusted linear mixed random effect models.

RESULTS

NT-proBNP and cTnI were positively associated with increasing age. NT-proBNP, but not cTnI, was affected by changes of renal function and the degree of obesity. NT-proBNP was more closely related than cTnI to changes in echocardiographic estimates of cardiac geometry and function. Biomarker levels and/or their changes were inversely associated with a physically more active lifestyle (both NT-proBNP and cTnI) and statin treatment at age 70 (only cTnI). Changes in smoking status or antihypertensive treatment had no effect on biomarker levels.

CONCLUSIONS

Changes in NT-proBNP and cTnI levels are associated with different patterns of cardiovascular disease burden when using a longitudinal approach. However, levels of both biomarkers and their changes also reflect changes in the cardiovascular risk profile that might be modifiable. This is an important aspect for the use of any cardiovascular biomarker in an elderly population.

Prevalence and outcome of patients referred for chest pain with high-sensitivity troponin elevation and no diagnosis at discharge

INTRODUCTION

Specialized chest pain units appear to increase the proportion of patients with acute chest pain who are properly evaluated, but some of them remain doubtful.

HYPOTHESIS

The aim of this study was to evaluate the survival and occurrence of cardiovascular events in patients without diagnosis at the end of management of chest pain with high-sensitivity troponin (Tn) elevation.

METHOD

All consecutive patients who came to the cardiac emergency room of Poitiers University Hospital between January 1, 2014, and August 7, 2015, for chest pain and Tn elevation were included. The primary endpoint was the number of undiagnosed patients; secondary endpoints included survival and major adverse cardiac events.

RESULTS

A total of 1001 patients (695 male; mean age, 68 ±16 years) who had chest pain and Tn elevation were included. Median follow-up was 24.5 (IQR, 14.7-29.5) months. Forty-seven (4.7%) patients remained without diagnosis. Compared with patients with diagnosis, these patients were younger (53.6 ±19.7 years; P < 0.0001) and had less hypertension (29.8%; P < 0.0001), diabetes (4.3%; P = 0.0016), and history of coronary artery disease (6.4%; P < 0.0001). No patients died or experienced MACE in 6-month follow-up. Survival curves showed the probability of survival was excellent, not only at 6 months, but also at 36 months (P = 0.0025).

CONCLUSIONS

Less than 5% of patients referred for chest pain and with high-sensitivity Tn elevation remained without diagnosis after adapted care in the chest pain unit. Their 6-month prognosis was excellent.

Non-coding RNAs as biomarkers for acute myocardial infarction

Acute myocardial infarction (AMI) is a main threat to human lives worldwide. Early and accurate diagnoses warrant immediate medical care, which would reduce mortality and improve prognoses. Circulating non-coding RNAs have been demonstrated to serve as competent biomarkers for various diseases. Following the identification of cardiac-specific microRNA miR-208a in circulation, more non-coding RNAs (miR-1, miR-499 and miR-133) have been identified as biomarkers not only for the diagnosis of AMI but also for prognosis post infarction. Here, we summarized recent findings on non-coding RNAs as biomarkers for early diagnosis of ST-segment elevation myocardial infarction and for disease monitoring of myocardial infarction. In addition, the prognostic potential of non-coding RNAs in patients treated with percutaneous coronary intervention was also described. We also include studies based on biobanks, and build a miRNA release spectrum after AMI, which provides quantitative and time-lapse monitoring of AMI progress. With this spectrum, we are able to customize personal medical care, which prevents further damage. By constructing a network of circulating non-coding RNAs with high specificity and sensitivity, detailed diagnostic information was provided for personalized medicine. Unveiling the roles and kinetics of circulating non-coding RNAs may lead to a revolution in clinical diagnosis.

Clinical implications of high-sensitivity cardiac troponins

Cardiac troponin assays have become more sensitive over the years leading to the clinical introduction of high-sensitivity cardiac troponin assays in 2010. Their use has revolutionized the assessment of patients with chest pain in the emergency department by allowing earlier rule-in and rule-out of myocardial infarction leading to shorter stays in the emergency department and reduced admissions for chest pain. The incidence of myocardial infarction has increased slightly, and patients with myocardial infarction diagnosed with high-sensitivity cardiac troponins have been found to have a reduced risk of reinfarction, though without an impact on survival. High-sensitivity cardiac troponins are powerful predictors of long-term mortality and cardiovascular disease in the general population as well as in patients with chest pain with or without cardiovascular disease. The increase in risk for death and cardiovascular disease associated with high-sensitivity cardiac troponins is graded and starts already at detectable levels, well below the upper normal level. The aim of this review was to describe the clinical use and consequences of the introduction of high-sensitivity cardiac troponins. In addition, the importance of persistently elevated troponin levels for prognosis and what investigations may be appropriate to perform in patients with stable troponin elevations are discussed.

Relationship between high-sensitivity cardiac troponin T and the prognosis of elderly inpatients with non-acute coronary syndromes

Objective

Low-level high-sensitivity cardiac troponin T (hs-cTnT) increases in elderly population. In this study, the relationship between hs-cTnT level and all-cause death of elderly inpatients with non-acute coronary syndrome (non-ACS) after discharge from the hospital was investigated.

Materials and methods

Non-ACS patients aged >65 years admitted in the General Practice Wards and Department of Geriatrics of Fuxing Hospital Affiliated to Capital Medical University were enrolled in the study. The patients were grouped according to the tertiles of hs-cTnT levels. Biochemical markers, hs-cTnT, and amino-terminal pro-brain natriuretic peptide were measured. The median follow-up period was 47 months, and all-cause deaths of the patients were observed.

Results

A total of 722 patients, including 473 males and 249 females, aged 65-98 (82.43±5.98) years were enrolled in the study. The level of hs-cTnT was found to be higher in males, and increased with age and comorbidities (P<0.01). Compared with low-level group, NT-proBNP level of patients in high-level group was higher, while hemoglobin (Hb), estimated glomerular filtration rate (eGFR), and left ventricular ejection fraction (LVEF) levels were lower (P<0.001). The mortality rate increased significantly with increased hs-cTnT levels (P<0.001). The total number of deaths was 136 (18.8%), and of these, 108 (79.4%) were noncardiac deaths. Risk of all-cause deaths in the highest hs-cTnT level group was 7.3 times higher than that of the lowest hs-cTnT level group (95% CI: 4.29-12.51, P<0.001). After adjusting for gender, age, comorbidities, NT-proBNP, Hb, eGFR, and LVEF, hs-cTnT level still affected the patient's survival time (HR: 3.01, 95% CI: 1.67-5.43, P<0.001).

Conclusion

These findings suggest that low-level hs-cTnT was increased in elderly inpatients without ACS. They further highlight that baseline hs-cTnT level was associated with increased risk of all-cause deaths among patients after their discharge, and most deaths were from non-cardiovascular diseases.

Adjusted Troponin I for Improved Evaluation of Patients with Chest Pain

The use of cardiac troponins (cTn) is the gold standard for diagnosing myocardial infarction. Independent of myocardial infarction (MI), however, sex, age and kidney function affect cTn levels. Here we developed a method to adjust cTnI levels for age, sex, and renal function, maintaining a unified cut-off value such as the 99th percentile. A total of 4587 individuals enrolled in a prospective longitudinal study were used to develop a model for adjustment of cTn. cTnI levels correlated with age and estimated glomerular filtration rate (eGFR) in males/females with rage = 0.436/0.518 and with reGFR = -0.142/-0.207. For adjustment, these variables served as covariates in a linear regression model with cTnI as dependent variable. This adjustment model was then applied to a real-world cohort of 1789 patients with suspected acute MI (AMI) (N = 407). Adjusting cTnI showed no relevant loss of diagnostic information, as evidenced by comparable areas under the receiver operator characteristic curves, to identify AMI in males and females for adjusted and unadjusted cTnI. In specific patients groups such as in elderly females, adjusting cTnI improved specificity for AMI compared with unadjusted cTnI. Specificity was also improved in patients with renal dysfunction by using the adjusted cTnI values. Thus, the adjustments improved the diagnostic ability of cTnI to identify AMI in elderly patients and in patients with renal dysfunction. Interpretation of cTnI values in complex emergency cases is facilitated by our method, which maintains a single diagnostic cut-off value in all patients.

Biomarkers to Assess Right Heart Pressures in Recipients of a Heart Transplant: A Proof-of-Concept Study

Background

This proof-of-concept study investigated the feasibility of using biomarkers to monitor right heart pressures (RHP) in heart transplanted (HTx) patients.

Methods

In 298 patients, we measured 7.6 years post-HTx mean pressures in the right atrium (mRAP) and pulmonary artery (mPAP) and capillaries (mPCWP) along with plasma high-sensitivity troponin T (hsTnT), a marker of cardiomyocyte injury, and the multidimensional urinary classifiers HF1 and HF2, mainly consisting of dysregulated collagen fragments.

Results

In multivariable models, mRAP and mPAP increased with hsTnT (per 1-SD, +0.91 and +1.26 mm Hg; P < 0.0001) and with HF2 (+0.42 and +0.62 mm Hg; P ≤ 0.035), but not with HF1. mPCWP increased with hsTnT (+1.16 mm Hg; P < 0.0001), but not with HF1 or HF2. The adjusted odds ratios for having elevated RHP (mRAP, mPAP or mPCWP ≥10, ≥24, ≥17 mm Hg, respectively) were 1.99 for hsTnT and 1.56 for HF2 (P ≤ 0.005). In detecting elevated RHPs, areas under the curve were similar for hsTnT and HF2 (0.63 vs 0.65; P = 0.66). Adding hsTnT continuous or per threshold or HF2 continuous to a basic model including all covariables did not increase diagnostic accuracy (P ≥ 0.11), whereas adding HF2 per optimized threshold increased both the integrated discrimination (+1.92%; P = 0.023) and net reclassification (+30.3%; P = 0.010) improvement.

Conclusions

Correlating RHPs with noninvasive biomarkers in HTx patients is feasible. However, further refinement and validation of such biomarkers is required before their clinical application can be considered.

Cardiac troponins: 25 years on the stage and still improving their clinical value

Twenty-five years ago, non-isotopic immunoassays for measuring the cardiac specific isoforms of troponin I (cTnI) and T (cTnT) were developed. Both biomarkers radically changed the diagnosis, prognosis, and therapy indication of acute coronary syndromes (ACS) and, particularly, of myocardial infarction (MI). However, cardiac troponins (cTn) rapidly demonstrated their usefulness in other cardiac and non-cardiac conditions, a part of the ischemic coronary diseases. Consequently, the number of patients to be tested for cTn and the number of tests requested to clinical laboratories sharply increased. Though the manufacturers continuously improved the analytical characteristics of the first cTn assays and produced different cTn assay "generations", the universal definition of myocardial infarction required less-than-available analytical imprecision at the cTn concentration used to assess MI (i.e. the 99th reference percentile). To address the clinical requirements, manufacturers developed the high-sensitivity cTn (hs-cTn) assays that allow to measure the 99th reference percentile with adequate precision, to detect cTn in many healthy subjects and, hence, to calculate the hs-cTn biological variation and especially to observe in very short time intervals serial differences in hs-cTn attributable to cardiac ischemia. Since the number of patients attending the emergency departments (ED) for a suspected ACS or MI is increasing, the improved properties of hs-cTn assays, allowing faster and safer patient assessment, will help to alleviate the sometimes overcrowded EDs. However, there are many biological, analytical, and clinical factors that can influence the true hs-cTn values of a patient. Clinicians and laboratory professionals should know about them for the best interpretation of the otherwise largely useful hs-cTn measurements. In conclusion, 25 years after their introduction for clinical use, "cTn are still on the stage and improving their clinical value".

Stable High-Sensitivity Cardiac Troponin T Levels and Outcomes in Patients With Chest Pain

BACKGROUND

There is a paucity of data on the association between high-sensitivity cardiac troponin (hs-cTn) levels and outcomes in patients with chest pain but no myocardial infarction (MI), or any other condition that may lead to acutely elevated troponin levels.

OBJECTIVES

The authors hypothesized that any detectable high-sensitivity cardiac troponin T (hs-cTnT) level is associated with adverse outcomes.

METHODS

All patients (N = 22,589) >25 years of age with chest pain and hs-cTnT analyzed concurrently in the emergency department of Karolinska University Hospital, Stockholm, Sweden from 2011 to 2014 were eligible for inclusion. After excluding all patients with acute conditions that may have affected hs-cTnT, or MI associated with the visit, or insufficient information to determine whether troponin levels were stable, Cox regression was used to estimate risks for all-cause, cardiovascular, and noncardiovascular mortality, MI, and heart failure at different levels of troponins.

RESULTS

A total of 19,460 patients with a mean age of 54 ± 17 years were included. During a mean follow-up of 3.3 ± 1.2 years, 1,349 (6.9%) patients died. Adjusted hazard ratios (with 95% confidence intervals) for all-cause mortality were 2.00 (1.66 to 2.42), 2.92 (2.38 to 3.59), 4.07 (3.28 to 5.05), 6.77 (5.22 to 8.78), and 9.68 (7.18 to 13.00) in patients with hs-cTnT levels of 5 to 9, 10 to 14, 15 to 29, 30 to 49, and ≥50 ng/l, respectively, compared with patients with hs-cTnT levels <5 ng/l. There was a strong and graded association between all detectable levels of hs-cTnT and risk for MI, heart failure, and cardiovascular and noncardiovascular mortality.

CONCLUSIONS

Among patients with chest pain and stable troponin levels, any detectable level of hs-cTnT is associated with an increased risk of death and cardiovascular outcomes and should merit further attention.

Heart-type fatty acid-binding protein in cardiovascular disease: A systemic review

Fatty acid-binding proteins, whose clinical applications have been studied, are a family of proteins that reflect tissue injury. Heart-type fatty acid-binding protein (H-FABP) is a marker of ongoing myocardial damage and useful for early diagnosis of acute myocardial infarction (AMI). In the past decade, compared to other cardiac enzymes, H-FABP has shown more promise as an early detection marker for AMI. However, the role of H-FABP is being re-examined due to recent refinement in the search for newer biomarkers, and greater understanding of the role of high-sensitivity troponin. We discuss the current role of H-FABP as an early marker for AMI in the era of high sensitive troponin. H-FABP is highlighted as a prognostic marker for a broad spectrum of fatal diseases, viz., AMI, heart failure, arrhythmia, and pulmonary embolism that could be associated with poor clinical outcomes. Because the cut-off value of what constitutes an abnormal H-FABP potentially differs for each cardiovascular event and depends on the clinical setting, an optimal cut-off value has not been clearly established. Of note, several factors such as age, gender, and cardiovascular risk factors, which affect H-FABP levels need to be considered in this context. In this review, we discuss the clinical applications of H-FABP as a prognostic marker in various clinical settings.

Outcomes in Patients With Chest Pain Discharged After Evaluation Using a High-Sensitivity Troponin T Assay

BACKGROUND

Most patients with chest pain are discharged from the emergency department (ED) with the diagnosis "unspecified chest pain." It is unknown if evaluation with a high-sensitivity troponin T (hsTnT) assay affects prognosis in this large population.

OBJECTIVES

The aim was to investigate whether the introduction of an hsTnT assay is associated with reduced incidence of major adverse cardiac events (MACEs) and cardiovascular (CV) risk profile in patients with chest pain discharged from the ED.

METHODS

The study included 65,696 patients with "unspecified chest pain" discharged from 16 Swedish hospital EDs between 2006 and 2013 in which an hsTnT assay was introduced as the clinical routine. Patients evaluated with a conventional and an hsTnT assay were compared regarding the occurrence of 30-day MACE and CV risk profile based on information from national registries. Patients directly discharged and those discharged after an initial admission were analyzed separately.

RESULTS

Fewer directly discharged patients experienced a MACE when evaluated with an hsTnT compared with a conventional assay (0.6% vs. 0.9%; odds ratio [OR]: 0.7; 95% confidence interval [CI]: 0.57 to 0.83). In contrast, more patients discharged after an initial admission experienced a MACE when evaluated with an hsTnT (7.2% vs. 3.4%; OR: 2.18; 95% CI: 1.76 to 2.72). Admitted patients had a higher general CV risk profile when evaluated with hsTnT, whereas directly discharged patients had a lower general CV risk profile with the same test.

CONCLUSIONS

Patients directly discharged from the ED with unspecified chest pain experienced fewer MACEs and had a better risk profile when evaluated with hsTnT. Our findings suggest that more true at-risk patients were identified and admitted. The implementation of hsTnT assays in Swedish hospitals has improved evaluations in the ED.

Age-related remodeling of the JAK/STAT/SOCS signaling pathway and associated myocardial changes: From histological to molecular level

BACKGROUND

The cellular and molecular mechanisms implicated in age-associated changes in myocardial structure are of paramount importance since they cause profound alterations in the functional response and represent targets for alleviating age-related pathologies. One of these mechanisms is the JAK/STAT/SOCS signaling pathway.

AIM OF THE STUDY

The present study is designed to elucidate age-dependent changes of the myocardium to provide morphological basis displaying the pathogenesis of myocardial hypertrophy, fibrosis and inflammation with aging.

MATERIAL AND METHODS

Thirty male Sprague Dawley rats aged; 6, 30 and 36 months were used in this study. The animals were divided into three age groups, young adult, senile and very senile rats, respectively. The heart weight/body weight ratio was determined. The heart was subjected to gross morphologic examination, microscopic examination using H&E and Masson's trichrome stains and immunohistochemical examination for detection of JAK, pSTAT3, α-SMA, β-MHC and CD45. Western blotting was also carried out to detect SOCS genes. Real-time PCR was used to detect the inflammatory markers TNFα and IL1β and the hypertrophy marker α-SKA. Biochemical analysis of cardiac troponin I and creatine kinase-MB was done. Quantitative histomorphometric estimations included estimation of cardiac myocyte cross sectional area, estimation of the area percent of collagen fibers in Masson's trichrome stained sections and determination of optical density in immunostained sections. Electron microscopic examination was done to determine capillary density.

RESULTS

Jak and pSTAT3 were predominantly localized to the nuclei and exhibited progressive decline with aging, while SOCS3 activity displayed an age-related increase. The aged myocardium displayed profound age associated structural changes as well as myocardial hypertrophy, fibrosis and inflammation in senile and very senile rats.

CONCLUSION

The age-related modifications in the JAK/STAT/SOCS signaling as well as the age-associated pathological changes in myocardial structure are of particular interest as they provide further insight in age-associated heart pathologies and represent potential targets for cardioprotective and therapeutic approaches.

Prognostic Value of High-Sensitivity Cardiac Troponin T Compared with Risk Scores in Stable Cardiovascular Disease

BACKGROUND

Risk stratification of patients with cardiovascular disease remains challenging despite consideration of risk scores.

METHODS

We aimed to evaluate the prognostic performance of high-sensitivity cardiac troponin T in a low-risk outpatient population presenting for nonsecondary and secondary prevention. All-cause mortality, a composite of all-cause mortality, acute myocardial infarction, and stroke (end point 2), and a composite of all-cause mortality, acute myocardial infarction, stroke and rehospitalization for acute coronary syndrome, and decompensated heart failure (end point 3) were defined. The prognostic performance of high-sensitivity cardiac troponin T on index visit was compared with the PROCAM score and 3 FRAMINGHAM subscores.

RESULTS

In 693 patients with a median follow-up of 796 days, we observed 16 deaths, 32 patients with end point 2, and 83 patients with end point 3. All risk scores performed better in the prediction of all-cause mortality in nonsecondary prevention (area under the curve [AUC]: PROCAM: 0.922 vs 0.523, P = .001, consistent for all other scores). In secondary prevention, high-sensitivity cardiac troponin T outperformed all risk scores in the prediction of all-cause mortality (ΔAUC: PROCAM: 0.319, P <.001, consistent for all other scores) and performed superiorly in the prediction of end point 2 compared with the PROCAM, FRAMINGHAM-Coronary Heart Disease, and FRAMINGHAM-Hard Coronary Heart Disease scores (ΔAUC: PROCAM: 0.176, P = .047, consistent for FRAMINGHAM-Coronary Heart Disease and FRAMINGHAM-Hard Coronary Heart Disease). In nonsecondary prevention, we observed a comparable prognostic performance of high-sensitivity cardiac troponin T and multivariable risk scores. Our findings on the prediction of all-cause mortality compared with the FRAMINGHAM-Hard Coronary Heart Disease score were confirmed in an independent validation cohort on 2046 patients.

CONCLUSIONS

High-sensitivity troponin T provides excellent risk stratification regarding all-cause mortality and all-cause mortality, acute myocardial infarction, and stroke in a secondary prevention cohort in whom risk scores perform poorly.

The 99th percentile of reference population for cTnI and cTnT assay: methodology, pathophysiology and clinical implications

According to recent international guidelines, including the 2012 Third Universal Definiton of Myocardial Infarction by the Joint ESC/ACCF/AHA/WHF Task Force, an increase in cardiac troponin (cTn) levels over the 99th percentile upper reference limit (99th URL) should be considered clinically relevant, this cut-off being measured with an imprecision ≤10 CV%. In theory 99th URL values strongly depend not only on demographic and physiological variables (i.e. criteria for considering the reference population “healthy”), but also on the analytical performance of cTn methods and mathematical algorithms used for the calculation. The aim of the present article was therefore to review the methodological and pathophysiological factors affecting the evaluation and calculation of the 99th URL for cTn assay. The critical analysis made showed that no uniform procedure is followed, and nor have experts or regulatory bodies provided uniform guidelines for researchers or cTn assays manufacturers as an aid in “their quest to define normality”. In particular, little attention has been paid to the way in which a healthy reference population is to be selected, or the criteria for calculating the 99th URL value for cTn assays, thus highlighting the need for international recommendations not only for demographic and physiological variables criteria for defining a healthy reference population, but also for calculating mathematical algorithms for establishing/calculating clinical decision values. An expert consensus group, comprising laboratory and clinical scientists, biomedical statisticians, industrial and regulatory representatives, should be responsible for drawing up these guidelines.