Troponin in Heart Failure

Acute heart failure: mechanisms and pre-clinical models-a Scientific Statement of the ESC Working Group on Myocardial Function

While chronic heart failure (CHF) treatment has considerably improved patient prognosis and survival, the therapeutic management of acute heart failure (AHF) has remained virtually unchanged in the last decades. This is partly due to the scarcity of pre-clinical models for the pathophysiological assessment and, consequently, the limited knowledge of molecular mechanisms involved in the different AHF phenotypes. This scientific statement outlines the different trajectories from acute to CHF originating from the interaction between aetiology, genetic and environmental factors, and comorbidities. Furthermore, we discuss the potential molecular targets capable of unveiling new therapeutic perspectives to improve the outcome of the acute phase and counteracting the evolution towards CHF.

Differences between high-sensitivity cardiac troponin T and I in stable populations: underlying causes and clinical implications

OBJECTIVES

Measurement of high-sensitivity (hs) cardiac troponin (cTn) T and I is widely studied for cardiac assessment of stable populations. Recent data suggest clinical and prognostic discrepancies between both hs-cTn. We aimed at reviewing published studies with respect to underlying causes and clinical implications.

CONTENT

We summarized current evidence on release and clearance mechanisms of cTnT and I, and on preanalytical and assay-related issues potentially portending to differences in measured concentrations. We also performed a systematic review of outcome studies comparing both hs-cTn in the general population, patients with congestive heart failure, stable coronary artery disease and atrial fibrillation.

SUMMARY AND OUTLOOK

For the interpretation of concentrations of hs-cTnT, stronger association with renal dysfunction compared to hs-cTnI should be considered. Hs-cTnT also appears to be a stronger indicator of general cardiovascular morbidity and all-cause mortality. Hs-cTnI concentrations tend to be more sensitive to coronary artery disease and ischemic outcomes. These findings apparently reflect variations in the mechanisms of cardiac affections resulting in cTn release. Whether these differences are of clinically relevance remains to be elucidated. However, having the option of choosing between either hs-cTn might represent an option for framing individualized cardiac assessment in the future.

Effects of e-waste exposure on biomarkers of coronary heart disease (CHD) and their associations with level of heavy metals in blood

Excess heavy metals increase the risk of various diseases. Electronic waste (e-waste) is a potential route to heavy metal exposure, and Taizhou is a large e-waste dismantling area in China. In this study, we acquire blood samples from residents living near an e-waste recycling area (exposed group) and other residents in a selected reference area (reference group) for a comparative study in Taizhou in December 2017. Seven heavy metals, including cobalt (Co), nickel (Ni), cadmium (Cd), tin (Sn), copper (Cu), zinc (Zn), and lead (Pb), are quantitatively determined in all blood samples. It is discovered that the levels of Co, Ni, Sn, and Pb in the exposed group are higher than those in the reference group. Additionally, two crucial biomarkers of coronary heart disease (CHD), i.e., troponin (Tn) and myeloperoxidase (MPO), and two biomarkers of oxidative stress, i.e., malondialdehyde (MDA) and 8-isoprostane (8-I), are measured. We discovered that the levels of these indicators in the exposed group are significantly higher than those in the reference group. Meanwhile, both the Spearman correlation and multiple linear regression analysis show that Ni is positively correlated with Tn, MPO, 8-I, and MDA. Hence, we hypothesize that exposure to e-waste increases the risk of CHD and that Ni is an important contributor to the initiation of the disease.

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

Background

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

Methods

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

Results

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

Conclusions

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

Inpatient versus outpatient intravenous diuresis for the acute exacerbation of chronic heart failure

BACKGROUND

We established an IV outpatient diuresis (IVOiD) clinic and conducted a quality improvement project to evaluate safety, effectiveness and costs associated with outpatient versus inpatient diuresis for patients presenting with acute decompensated heart failure (ADHF) to the emergency department (ED).

METHODS

Patients who were clinically diagnosed with ADHF in the ED, but did not have high-risk features, were either diuresed in the hospital or in the outpatient IVOiD clinic. The dose of IV diuretic was based on their home maintenance diuretic dose. The outcomes measured were the effects of diuresis (urine output, weight, hemodynamic and laboratory abnormalities), 30-90 day readmissions, 30-90 day death and costs.

RESULTS

In total, 36 patients (22 inpatients and 14 outpatients) were studied. There were no significant differences in the baseline demographics between groups. The average inpatient stay was six days and the average IVOiD clinic days were 1.2. There was no significant difference in diuresis per day of treatment (1159 vs. 944 ml, p = 0.46). There was no significant difference in adverse outcomes, 30-90 day readmissions or 30-90 day deaths. There was a significantly lower cost in the IVOiD group compared to the inpatient group ($839.4 vs. $9895.7, p=<0.001).

CONCLUSIONS

Outpatient IVOiD clinic diuresis may be a viable alternative to accepted clinical practice of inpatient diuresis for ADHF. Further studies are needed to validate this in a larger cohort and in different sites.

Factors and Prognostic Significance of Impaired Exercise Tolerance in Women over 40 with Arterial Hypertension

The aim of this study was to identify factors influencing maximal oxygen uptake (VO_2max) and early identification of the profile of hypertensive women in the perimenopausal period at risk of heart failure. This study included 185 female patients. Regression analyses determined predictors of the lowest VO_2max (quartile 1: VO_2max < 17 mL/kg/min). Females with the lowest oxygen consumption had a significantly higher level of high sensitive cardiac Troponin T (hs-cTnT) (p = 0.001), higher values of the left atrial (LA) volume, late diastolic mitral annulus velocity (A′), E/E′ (p = 0.0003, p = 0.02, p = 0.04; respectively), higher BMI and fat content (kg and %) (p < 0.0001), higher fat free mass (FFM) (kg) (p < 0.0001), total body water content (TBW) (p = 0.0002) as well as extracellular body water content (ECW) (p < 0.0001) and intracellular body water content (ICW) (p = 0.005), ECW/TBW × 100% (p < 0.0001) and metabolic age (p < 0.0001) and lower E′ (p = 0.001) compared to controls. In a multiple logistic regression model independently associated with VO_2max were: ECW/TBW × 100% (OR 4.45, 95% CI: 1.77–11.21; p = 0.002), BMI (OR 7.11, 95% CI: 2.01–25.11; p = 0.002) and hs-cTnT level (OR 2.69, 95% CI: 1.23–5.91; p = 0.013). High-sensitivity cardiac troponin may serve as an early biomarker of heart failure in hypertensive women. Hydration status should be considered in overall hypertensive women care. There is an importance of body mass compartments analysis in the early identification of hypertensive females at risk of heart failure. Optimization and personalization of body structure may be a preventive method for this disease. ClinicalTrials.gov Identifier: NCT04802369.

The role of antibody-based troponin detection in cardiovascular disease: A critical assessment

Cardiovascular disease has remained the world's biggest killer for 30 years. To aid in the diagnosis and prognosis of patients suffering cardiovascular-related disease accurate detection methods are essential. For over 20 years, the cardiac-specific troponins, I (cTnI) and T (cTnT), have acted as sensitive and specific biomarkers to assist in the diagnosis of various types of heart diseases. Various cardiovascular complications were commonly detected in patients with COVID-19, where cTn elevation is detectable, which suggested potential great prognostic value of cTn in COVID-19-infected patients. Detection of these biomarkers circulating in the bloodstream is generally facilitated by immunoassays employing cTnI- and/or cTnT-specific antibodies. While several anti-troponin assays are commercially available, there are still obstacles to overcome to achieve optimal troponin detection. Such obstacles include the proteolytic degradation of N and C terminals on cTnI, epitope occlusion of troponin binding-sites by the cTnI/cTnT complex, cross reactivity of antibodies with skeletal troponins or assay interference caused by human anti-species antibodies. Therefore, further research into multi-antibody based platforms, multi-epitope targeting and rigorous validation of immunoassays is required to ensure accurate measurements. Moreover, with combination and modification of various latest technical (e.g. microfluidics), antibody-based troponin detection systems can be more specific, sensitive and rapid which could be incorporated into portable biosensor systems to be used at point-of care.

Prognostic Value of Isolated Elevated Troponin I Levels in Patients without Acute Coronary Syndrome Admitted to the Emergency Department

Fundamento:

Embora a elevação não isquêmica da troponina seja frequentemente observada em pacientes admitidos no pronto-socorro (PS), não há consenso quanto ao seu manejo.

Objetivos:

Este estudo teve como objetivo caracterizar os pacientes admitidos no PS com elevação da troponina não-isquêmica e identificar potenciais preditores de mortalidade nessa população.

Métodos:

Este estudo observacional retrospectivo incluiu pacientes do PS com resultado positivo no teste da troponina entre junho e julho de 2015. Pacientes com diagnóstico clínico de síndrome coronariana aguda (SCA) foram excluídos. Os dados demográficos dos pacientes e as variáveis clínicas e laboratoriais foram extraídos dos prontuários médicos. Os dados do seguimento foram obtidos por 16 meses ou até a ocorrência de morte. O nível de significância estatística foi de 5%.

Resultados:

A elevação da troponina sem SCA foi encontrada em 153 pacientes no PS. A mediana (IIQ) de idade dos pacientes foi de 78 (19) anos, 80 (52,3%) eram do sexo feminino e 59 (38,6%) morreram durante o seguimento. A mediana do período de seguimento (IIQ) foi de 477 (316) dias. Os sobreviventes eram significativamente mais jovens 76 (24) vs. 84 (13) anos; p=0,004) e apresentaram uma maior proporção de elevação da troponina isolada (sem elevação da creatina quinase ou mioglobina) em duas avaliações consecutivas: 48 (53,9%) vs. 8 (17,4%), p<0,001. Os sobreviventes também apresentaram menor taxa de tratamento antiplaquetário e internação no mesmo dia. Na regressão logística multivariada com ajuste para variáveis significativas na análise univariada, a elevação isolada da troponina em duas avaliações consecutivas mostrou hazard ratio = 0,43 (IC95% 0,17–0,96, p=0,039); hospitalização, tratamento antiplaquetário anterior e idade permaneceram independentemente associados à mortalidade.

Conclusões:

A elevação isolada da troponina em duas medidas consecutivas foi um forte preditor de sobrevida em pacientes no PS com elevação da troponina, mas sem SCA.

Predictors associated with increased troponin in acute decompensated and chronic heart failure patients

Background: Myocardial injury (INJ) expressed by elevated high-sensitivity troponin (hs-Tn) is common in heart failure (HF), due to cardiovascular and non-cardiac conditions. The mechanisms of INJ in acute decompensated HF (ADHF) versus chronic HF (CHF) are still debated. This study’s purpose was to evaluate the determinants of elevated hs-TnT in ADHF and CHF.

Methods: We retrospectively analyzed consecutive HF patients with hs-TnT measured on admission, hospitalized in a tertiary-care hospital. Rehospitalizations, acute coronary syndromes, embolisms, infections, autoimmunity and malignancy were excluded. Cut-off point for hs-TnT was 14 ng/L.

Results: Our study included 488 HF patients, 56.55% with ADHF. Mean age was 72.52±10.09 years. 53.89% were females. 67.75% ADHF and 45.75% CHF patients had elevated hs-TnT. Median hs-TnT was higher in ADHF versus CHF (21.05[IQR 12.74-33.81] vs 13.20[IQR 7.93-23.25], p<0.0001). In multivariable analysis in ADHF and CHF, log10NT-proBNP (HR=5.30, 95%CI 2.71–10.38, p<0.001, respectively HR=5.49, 95%CI 1.71–17.57, p=0.004) and eGFR (HR=0.72, 95%CI 0.62–0.85, p<0.001, respectively HR=0.71, 95%CI 0.55–0.93, p=0.014) were independent predictors for increased hs-TnT. Independent factors associated with elevated hs-TnT in ADHF were male sex (HR=2.52, 95%CI 1.31-4.87, p=0.006) and chronic pulmonary obstructive disease (COPD) (HR=10.57, 95%CI 1.26-88.40, p=0.029), while in CHF were age (HR=2.68, 95%CI 1.42-5.07, p=0.002) and previous stroke (HR=5.35, 95%CI 0.98-29.20, p=0.053).

Conclusion: HF severity, expressed by NT-proBNP levels, and kidney disease progression, expressed by eGFR, were independent predictors associated with increased hs-TnT in both ADHF and CHF. Specific independent predictors were also indentified in ADHF (male sex, COPD) and CHF (age, history of stroke).

Myocardial ischemia and coronary disease in heart failure

Heart failure is a complex clinical syndrome and represents the final path of numerous heart diseases. Coronary artery disease is recognized as the primary risk factor for heart failure development, being the main etiological factor in more than 50% of heart failure patients in North America and Europe. Regardless of overt coronary artery disease, myocardial ischemia is a common finding in failing hearts, likely due to structural or functional coronary circulation alterations. Ischemia is a self-propagating process which irreversibly impairs the cardiac function and negatively impacts prognosis. Thus, a better and thorough understanding of myocardial ischemia pathophysiology in heart failure would likely lead to significantly improved outcomes in these patients. This review aims to describe the mechanisms of myocardial ischemia and coronary artery disease in heart failure, focusing on coronary circulation dysfunctions due to increased parietal stress or non-obstructive coronary disease, and discussing the association and management of coronary artery disease in patients with heart failure.

Troponins in Heart Failure - a Perpetual Challenge

Increased troponin levels in HF are a frequent and significant finding, as it strongly correlates with the underlying pathogenic mechanisms, diagnosis and prognosis. The advent of hs-cTn testing, as opposed to conventional troponin testing, led to additional difficulties in result interpretation. Most frequently, though not exclusively, increased cTn levels in acute or chronic failure is correlated, with myocardial necrosis (AMI); the diagnosis of AMI is confirmed if other criteria are fulfilled, as described in the fourth Universal Definition of Myocardial Infarction. Increased cTn levels below the cut-off for AMI suggest acute or chronic injury, depending on the ascending and/or descending trend curve or stable levels of cTn on serial testing. In acute or chronic HF with reduced or preserved EF, increased cTn levels carry prognostic value for adverse outcomes. Acute and chronic HF, as well as other ischemic or non-ischemic conditions, may lead to a transient increase in cTn levels: hypertensive crises, tachyarrhythmias, valvular regurgitation, myocarditis, stroke, mandating differential diagnosis with ACS. There are multiple mechanisms that explain increased levels of cTn: myocardial necrosis or coronary thrombosis (type I MI), supply-demand mismatch with subendocardial ischemia/injury, cardiomyocyte apoptosis, inflammatory cytokines, neurohomonal changes. Screening for cTn levels in the population at high cardiovascular risk yields prognostic information on development of de novo HF or other cardiovascular adverse events.

Monitoring of biomarkers in heart failure

The role of biomarkers is increasingly recognized in heart failure (HF) management, for diagnosis, prognostication, and screening of high-risk patients. Beyond natriuretic peptides and troponins, the utility of novel, emerging biomarkers is less established. This document reflects the key points of a Heart Failure Association of the European Society of Cardiology (ESC) consensus meeting on biomarker monitoring in HF.

Is Cardiac Troponin I Valuable to Detect Low-Level Myocardial Damage in Congestive Heart Failure?

Objectives:

Congestive heart failure (CHF) is a heart disease with a growing incidence and prevalence. Creatine kinase-myocardial base (CK-MB) is generally used to determine myocardial damage; however, it is insufficiently sensitive to measure the relatively low level of myocardial damage that typically occurs in heart failure (HF). The use of cardiac troponins, which are far more sensitive and specific, has become common to identify myocardial damage and permits the detection of even minute amounts of damage. The aim of this study was to ascertain whether cardiac troponin I (cTnI) can be used to detect low-level myocardial damage occurring in CHF in real-life conditions.

Methods:

Fifty patients with CHF symptoms (Group I) and 20 patients who were evaluated as normal (Group II) were included in this prospective study. The Framingham criteria were used to diagnose HF. Group I was divided into 3 subgroups according to the New York Heart Association classification of functional capacity: Class II, Group A; Class III, Group B, and Class IV, Group C. On the first day of admission, CK-MB and cTnI levels were measured and assessed quantitatively. The cTnI level was compared between these 3 subgroups and between Groups I and II. Linear regression analysis was performed to investigate the relationship between ejection fraction (EF) and cTnI.

Results

The mean cTnI value was 0.084±0.07 ng/mL in Group I and 0.018±0.012 ng/mL in Group II (p=0.0001). The mean cTnI value was 0.047±0.016 ng/mL, 0.080±0.048 ng/mL, and 0.175± 0.102 ng/mL in Groups A, B, and C, respectively. The difference between the subgroups of Group I was statistically significant. In addition, it was observed that there was a significant difference in the EF (%) value between Groups I and II and between Groups A, B, and C. Linear regression analysis revealed an inverse relationship between EF and cTnI (r: -0.66) (p=0.0001).

Conclusion

As the severity of HF increased, the cTnI serum level also increased. This increase was inversely related to the EF value. These results are consistent with other studies in the literature, suggesting that the cTnI level may be a useful marker in the diagnosis and evaluation of severity of HF.

The role of plasma N-terminal brain natriuretic pro-peptide in diagnosing elderly patients with acute exacerbation of COPD concurrent with left heart failure

Introduction

Acute exacerbation of COPD (AECOPD) and left heart failure (LHF) commonly exist together in clinical practice. However, the identification of AECOPD concurrent with LHF is currently challenging. Our study aimed to investigate the role of plasma N-terminal brain natriuretic pro-peptide (NT-proBNP) in diagnosing elderly patients with AECOPD associated with LHF.

Methods and results

LHF was diagnosed in patients with AECOPD according to echocardiographic criteria, and the levels of NT-proBNP in plasma were measured by quantitative electrochemiluminescence assay. Among the 655 patients with AECOPD, 158 (24.1%) had comorbid LHF, whether systolic (n=108, 68.4%) or diastolic (n=50, 31.6%). The plasma concentrations of NT-proBNP in elderly patients with AECOPD associated with LHF were markedly elevated, compared with those with only AECOPD (4,542.5 and 763.0 ng/L, respectively, P<0.01). The receiver operating characteristic curve indicated a diagnostic cutoff value of 1,677.5 ng/L of NT-proBNP in plasma for ascertaining the presence of LHF in AECOPD, with a sensitivity of 87.9%, a specificity of 88.5%, and an accuracy of 88.4%.

Conclusion

The plasma level of NT-proBNP may be a useful indicator in diagnosing AECOPD associated with LHF.

Myocardial Injury and Cardiac Reserve in Patients With Heart Failure and Preserved Ejection Fraction

BACKGROUND

Cardiac reserve is depressed in patients with heart failure and preserved ejection fraction (HFpEF). The mechanisms causing this are poorly understood.

OBJECTIVES

The authors hypothesized that myocardial injury might contribute to the hemodynamic derangements and cardiac reserve limitations that are present in HFpEF. Markers of cardiomyocyte injury, central hemodynamics, ventricular function, and determinants of cardiac oxygen supply-demand balance were measured.

METHODS

Subjects with HFpEF (n = 38) and control subjects without heart failure (n = 20) underwent cardiac catheterization, echocardiography, and expired gas analysis at rest and during exercise. Central venous blood was sampled to measure plasma high-sensitivity troponin T levels as an index of cardiomyocyte injury.

RESULTS

Compared with control subjects, troponins were more than 2-fold higher in subjects with HFpEF at rest and during exercise (p < 0.0001). Troponin levels were directly correlated with left ventricular (LV) filling pressures (r = 0.52; p < 0.0001) and diastolic dysfunction (r = -0.43; p = 0.002). Although myocardial oxygen demand was similar, myocardial oxygen supply was depressed in HFpEF, particularly during exercise (coronary perfusion pressure-time integral; 44 ± 9 mm Hg × s × min-1 × l × dl-1 vs. 30 ± 9 mm Hg × s × min-1 × l × dl-1; p < 0.0001), and reduced indices of supply were correlated with greater myocyte injury during exercise (r = -0.44; p = 0.0008). Elevation in troponin with exercise was directly correlated with an inability to augment LV diastolic (r = -0.40; p = 0.02) and systolic reserve (r = -0.57; p = 0.0003), greater increases in LV filling pressures (r = 0.55; p < 0.0001), blunted cardiac output response (r = -0.44; p = 0.002), and more severely depressed aerobic capacity in HFpEF.

CONCLUSIONS

Limitations in LV functional reserve and the hemodynamic derangements that develop secondary to these limitations during exercise in HFpEF are correlated with the severity of cardiac injury, assessed by plasma levels of troponin T. Further study is warranted to determine the mechanisms causing myocyte injury in HFpEF and the potential role of ischemia, and to identify and test novel interventions targeted to these mechanisms. (EXEC [Study of Exercise and Heart Function in Patients With Heart Failure and Pulmonary Vascular Disease]; NCT01418248).