Concentrations of Highly Sensitive Cardiac Troponin-I Predict Poor Cardiovascular Outcomes and Adverse Remodeling in Chronic Heart Failure

High-Sensitivity Cardiac Troponin Assays in Acute Heart Failure, Moving Beyond Myocardial Infarction

Cardiac troponins are essential structural proteins found in the contractile apparatus of cardiac myocytes. During myocardial damage, such as in myocardial infarction (MI), these troponins are released into the bloodstream. As a result, they play a central role in the diagnosis of MI, serving as sensitive and specific markers for cardiac injury. Earlier assays that were used for measuring troponin levels were considered as a dichotomous test, categorizing patients as being positive or negative for MI. The recent introduction of high-sensitivity cardiac troponin assays has revolutionized cardiac troponin detection. These assays can detect troponin levels that are 100 times lower than what traditional methods can detect. Hence it is now considered a quantitative measure of cardiac myocyte injury not only in the setting of MI but also in subjects without MI such as heart failure, in whom it can be regarded as a marker for myocardial stress. This review aims to establish the relationship between high-sensitivity cardiac troponin levels and the prognosis of patients suffering from acute heart failure. Additionally, this seeks to identify other applications where the release of troponin from the cardiomyocyte can provide prognostic information. This information can be vital in determining the appropriate treatment options for patients, ultimately improving their quality of life and positively impacting health economics.

Clinical markers in heart failure: a narrative review

Heart failure is a complex clinical syndrome that is one of the causes of high mortality worldwide. Additionally, healthcare systems around the world are also being burdened by the aging population and subsequently, increasing estimates of patients with heart failure. As a result, it is crucial to determine novel ways to reduce the healthcare costs, rate of hospitalizations and mortality. In this regard, clinical biomarkers play a very important role in stratifying risk, determining prognosis or diagnosis and monitoring patient responses to therapy. This narrative review discusses the wide spectrum of clinical biomarkers, novel inventions of new techniques, their advantages and limitations as well as applications. As heart failure rates increase, cost-effective diagnostic tools such as B-type natriuretic peptide and N-terminal pro b-type natriuretic peptide are crucial, with emerging markers like neprilysin and cardiac imaging showing promise, though larger studies are needed to confirm their effectiveness compared with traditional markers.

Heart failure with improved ejection fraction: Beyond diagnosis to trajectory analysis

Left ventricular (LV) systolic dysfunction represents a highly treatable cause of heart failure (HF). A substantial proportion of patients with HF with reduced ejection fraction (EF;HFrEF) demonstrate improvement in LV systolic function (termed HF with improved EF [HFimpEF]), either spontaneously or when treated with guideline-directed medical therapy (GDMT). Although it is a relatively new HF classification, HFimpEF has emerged in recent years as an important and distinct clinical entity. Improvement in LVEF leads to decreased rates of mortality and adverse HF-related outcomes compared to patients with sustained LV systolic dysfunction (HFrEF). While numerous clinical and imaging factors have been associated with HFimpEF, identification of which patients do and do not improve requires further investigation. In addition, patients improve at different rates, and what determines the trajectory of HFimpEF patients after improvement is incompletely characterized. A proportion of patients maintain improvement in LV systolic function, while others experience a recrudescence of systolic dysfunction, especially with GDMT discontinuation. In this review we discuss the contemporary guideline-recommended classification definition of HFimpEF, the epidemiology of improvement in LV systolic function, and the clinical course of this unique patient population. We also offer evidence-based recommendations for the clinical management of HFimpEF and provide a roadmap for future directions in understanding and improving outcomes in the care of patients with HFimpEF.

Prognostic value of high-sensitivity cardiac troponin for major adverse cardiovascular events in patients with diabetes: a systematic review and meta-analysis

Background

High-sensitivity cardiac troponin (hs-cTn) is associated with cardiovascular outcomes in the general population, but the prognostic value of hs-cTn in the diabetic population remains inconclusive. This study aimed to systematically review current evidence regarding the association between hs-cTn and the prognosis of diabetic patients.

Methods

MEDLINE, Embase, and the Cochrane Database were searched from inception to May, 2023. Observational studies that investigated the prognostic value of hs-cTn in diabetic patients were included in this meta-analysis. Studies were excluded if they did not report outcomes of interest, or urine hs-cTn were measured. Two independent investigators extracted and analyzed the data according to the PRISMA guidelines. The primary outcome was long-term major adverse cardiovascular events (MACE).

Results

We included 30 cohort studies of 62,419 diabetic patients. After a median follow-up of 5 (4.1-9.5) years, the pooled results suggested elevation of hs-cTn was associated with a significantly increased risk of MACE (adjusted hazard ratio (HR) per standard deviation (SD) change 1.15, 95% CI [1.06-1.25], I2 = 0%) and heart failure (adjusted HR per SD change 1.33, 95% CI [1.08-1.63], I2 = 0%) in patients with diabetes. No significant association was found regarding the association between elevation of hs-cTn and risk of all-cause mortality (adjusted HR per SD change 1.24, 95% CI [0.98-1.57], I2 = 0%). The results of sensitivity analyses were similar in prospective cohort studies, high-quality studies, or population without major cardiovascular comorbidities at baseline. hs-cTn may represent a strong and independent predictor of MACE and heart failure in diabetic patients. Future research is warranted to determine the appropriate cutoff value for hs-cTn with different comorbidities, for instance, diabetic nephropathy, peripheral artery diseases, etc.

Myocardial Recovery

In this paper, the feasibility of myocardial recovery is analyzed through a literature review. First, the phenomena of remodeling and reverse remodeling are analyzed, approached through the physics of elastic bodies, and the terms myocardial depression and myocardial recovery are defined. Continuing, potential biochemical, molecular, and imaging markers of myocardial recovery are reviewed. Then, the work focuses on therapeutic techniques that can facilitate the reverse remodeling of the myocardium. Left ventricular assist device (LVAD) systems are one of the main ways to promote cardiac recovery. The changes that take place in cardiac hypertrophy, extracellular matrix, cell populations and their structural elements, β-receptors, energetics, and several biological processes, are reviewed. The attempt to wean the patients who experienced cardiac recovery from cardiac assist device systems is also discussed. The characteristics of the patients who will benefit from LVAD are presented and the heterogeneity of the studies performed in terms of patient populations included, diagnostic tests performed, and their results are addressed. The experience with cardiac resynchronization therapy (CRT) as another way to promote reverse remodeling is also reviewed. Myocardial recovery is a phenomenon that presents with a continuous spectrum of phenotypes. There is a need for algorithms to screen suitable patients who may benefit and identify specific ways to enhance this phenomenon in order to help combat the heart failure epidemic.

A review of biomarker and imaging monitoring to predict heart failure recovery

Heart failure is a clinical syndrome caused by structural cardiac abnormalities that lead to increased intracardiac pressures and decreased cardiac output. Following cardiovascular insult or direct myocardial injury, neurohormonal activation triggers hemodynamic changes and cardiac remodeling to preserve cardiac output. While initially adaptive, cardiac remodeling eventually causes pathologic changes in cardiac structure that often compromise cardiac function. Reverse remodeling is the regression of abnormal cardiac chamber geometry and function after myocardial injury. In recent years, several classes of therapeutics have been associated with greater likelihood of reverse remodeling. Heart failure recovery and heart failure remission, terms encompassing the clinical correlates of reverse remodeling, have been associated with improved survival in patients with heart failure with reduced ejection. As such, identifying predictors of heart failure recovery can have important implications for guiding clinical practice and therapeutic innovation. This review addresses the role of biomarkers and imaging monitoring in predicting structural, functional, and clinical recovery in patients with acute and chronic heart failure.

Heart failure with recovered ejection fraction: Current understanding and future prospects

Heart failure with reduced ejection fraction (HFrEF) is a prevalent kind of heart failure in which a significant amount of the ejection fraction can be repaired, and left ventricular remodeling and dysfunction can be reversed or even restored completely. However, a considerable number of patients still present clinical signs and biochemical features of incomplete recovery from the pathophysiology of heart failure and are at risk for adverse outcomes such as re-deterioration of systolic function and recurrence of HFrEF. Furthermore, it is revealed from a microscopic perspective that even if partial or complete reverse remodeling occurs, the morphological changes of cardiomyocytes, extracellular matrix deposition, and abnormal transcription and expression of pathological genes still exist. Patients with "recovered ejection fraction" have milder clinical symptoms and better outcomes than those with continued reduction of ejection fraction. Based on the unique characteristics of this subgroup and the existence of many unknowns, the academic community defines it as a new category-heart failure with recovered ejection fraction (HFrecEF). Because there is a shortage of natural history data for this population as well as high-quality clinical and basic research data, it is difficult to accurately evaluate clinical risk and manage this population. This review will present the current understanding of HFrecEF from the limited literature.

Multidimensional Approach of Heart Failure Diagnosis and Prognostication Utilizing Cardiac Imaging with Biomarkers

Heart failure (HF) is a clinical syndrome caused by various etiologies that results in systolic and diastolic cardiac dysfunction with congestion. While evaluating HF and planning for treatment, physicians utilize various laboratory tests, including electrocardiography, diverse imaging tests, exercise testing, invasive hemodynamic evaluation, or endomyocardial biopsy. Among these, cardiac imaging modalities and biomarkers are the mainstays during HF diagnosis and treatment. Recent developments in non-invasive imaging modalities, such as echocardiography, computed tomography, magnetic resonance imaging, and nuclear imaging, have helped us understand the etiology, pathophysiology, and hemodynamics of HF, and determine treatment options and predict the outcomes. Due to the convenience of their use and potential impact on HF management, biomarkers are increasingly adopted in our clinical practice as well as research purpose. Natriuretic peptide is the most widely used biomarker for the diagnosis of HF, evaluation of treatment response, and prediction of future outcomes. Other cardiac biomarkers to evaluate the pathophysiological mechanisms of HF include myocardial injury, oxidative stress, inflammation, fibrosis, hypertrophy, and neurohormonal activation. Because HF results from complex cardiac disorders, it is essential to assess the disease status multidimensionally. The proper utilization of multimodality imaging and cardiac biomarkers can improve the quality of patient management and predict clinical outcomes in HF in the era of personalized medicine.

Cardiac remodelling - Part 2: Clinical, imaging and laboratory findings. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

In patients with heart failure, the beneficial effects of drug and device therapies counteract to some extent ongoing cardiac damage. According to the net balance between these two factors, cardiac geometry and function may improve (reverse remodelling, RR) and even completely normalize (remission), or vice versa progressively deteriorate (adverse remodelling, AR). RR or remission predict a better prognosis, while AR has been associated with worsening clinical status and outcomes. The remodelling process ultimately involves all cardiac chambers, but has been traditionally evaluated in terms of left ventricular volumes and ejection fraction. This is the second part of a review paper by the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology dedicated to ventricular remodelling. This document examines the proposed criteria to diagnose RR and AR, their prevalence and prognostic value, and the variables predicting remodelling in patients managed according to current guidelines. Much attention will be devoted to RR in patients with heart failure with reduced ejection fraction because most studies on cardiac remodelling focused on this setting.

Peak troponin T in STEMI: a predictor of all-cause mortality and left ventricular function

Background

The clinical significance of peak troponin levels following ST-elevation myocardial infarction (STEMI) has not been definitively established. The purpose of this study was to examine the relationship between peak high-sensitivity cardiac troponin T (hs-cTnT) and all-cause mortality at 30 days and 1 year, and left ventricular ejection fraction (LVEF) in STEMI.

Methods

A single-centre retrospective observational study was conducted of all patients with STEMI between January 2015 and December 2017. Demographics and clinical data were obtained through electronic patient records. Standard Bayesian statistics were employed for analysis.

Results

During the study period, 568 patients presented with STEMI. The mean age was 63.6±12 years and 76.4% were men. Of these, 535 (94.2%) underwent primary percutaneous coronary intervention, 12 (2.1%) underwent urgent coronary artery bypass and 21 (3.7%) were treated medically. Mean peak hs-cTnT levels were significantly higher in those who died within 30 days compared with those who survived (12 238 ng/L vs 4657 ng/L, respectively; p=0.004). Peak hs-cTnT levels were also significantly higher in those who died within 1 year compared with those who survived (10 319 ng/L vs 4622 ng/L, respectively; p=0.003). The left anterior descending artery was associated with the highest hs-cTnT and was the most common culprit in those who died at 1 year. An inverse relationship was demonstrated between peak hs-cTnT and LVEF (Pearson’s R=0.379; p<0.00001).

Conclusions

In STEMI, those who died at 30 days and 1 year had significantly higher peak troponin levels than those who survived. Peak troponin is also inversely proportional to LVEF with higher troponins associated with lower LVEF.

Circulating heart failure biomarkers beyond natriuretic peptides: review from the Biomarker Study Group of the Heart Failure Association (HFA), European Society of Cardiology (ESC)

New biomarkers are being evaluated for their ability to advance the management of patients with heart failure. Despite a large pool of interesting candidate biomarkers, besides natriuretic peptides virtually none have succeeded in being applied into the clinical setting. In this review, we examine the most promising emerging candidates for clinical assessment and management of patients with heart failure. We discuss high-sensitivity cardiac troponins (Tn), procalcitonin, novel kidney markers, soluble suppression of tumorigenicity 2 (sST2), galectin-3, growth differentiation factor-15 (GDF-15), cluster of differentiation 146 (CD146), neprilysin, adrenomedullin (ADM), and also discuss proteomics and genetic-based risk scores. We focused on guidance and assistance with daily clinical care decision-making. For each biomarker, analytical considerations are discussed, as well as performance regarding diagnosis and prognosis. Furthermore, we discuss potential implementation in clinical algorithms and in ongoing clinical trials.

Integrating High-Sensitivity Troponin T and Sacubitril/Valsartan Treatment in HFpEF: The PARAGON-HF Trial

OBJECTIVES

This study examined the relationship among high-sensitivity troponin-T (hs-TnT), outcomes, and treatment with sacubitril/valsartan in patients with heart failure (HF) and preserved ejection fraction (HFpEF).

BACKGROUND

hs-TnT is a marker of myocardial injury in HF.

METHODS

The PARAGON-HF trial randomized 4,796 patients with HFpEF to sacubitril/valsartan or valsartan. We compared the risk of the composite outcome of cardiovascular death (CVD) and total HF hospitalization (HHF) according to hs-TnT. We also assessed the effect of allocated treatment on hs-TnT.

RESULTS

hs-TnT was available in 1,141 patients (24%) at run-in (median value: 17 ng/L) and 1,260 (26%) at randomization, with 58.3% having hs-TnT >14 ng/L (upper limit of normal). During a median follow-up of 34 months, there were 393 outcome events (82 CVD, 311 HHF). Adjusting for demographics, comorbidities, left ventricular ejection fraction (LVEF), and N-terminal pro B-type natriuretic peptide (NT-proBNP), log-hs-TnT at randomization was an independent predictor of the composite outcome (HR: 1.38; 95% CI: 1.19-1.59; P < 0.001). Compared with valsartan, sacubitril/valsartan significantly reduced hs-TnT by 9% at week 16 (P < 0.001). Patients whose hs-TnT decreased from randomization to 16 weeks to at or below the median value of 17 ng/L subsequently had a lower risk of CVD/HHF compared with those with persistently elevated hs-TnT (P = 0.046). Patients with higher baseline hs-TnT (>17 ng/L) appeared to have a greater benefit from sacubitril/valsartan treatment when accounting for other potential effect modifiers (P interaction = 0.07).

CONCLUSIONS

Higher baseline hs-TnT was associated with increased risk of CVD/HHF, whereas hs-TnT decrease at 16 weeks led to lower subsequent risk of CVD/HHF compared with those who had persistently elevated values. Sacubitril/valsartan significantly reduced hs-TnT compared with valsartan. hs-TnT may be helpful in identifying patients with HFpEF who are more likely to benefit from sacubitril/valsartan.

A Test in Context: Interpretation of High-Sensitivity Cardiac Troponin Assays in Different Clinical Settings

High-sensitivity cardiac troponin (hs-cTn) assays have the ability to detect minute troponin concentrations and resolve minor changes in biomarker concentrations. Clinically, this allows for the ability to rapidly identify or exclude acute myocardial injury in the setting of acute chest discomfort-thus providing more rapid evaluation for acute myocardial infarction-but the improvements in troponin assays also create avenues for other applications where troponin release from the cardiomyocyte might confer prognostic information. These situations include cardiovascular risk assessment across a wide range of clinical circumstances, including apparently-well individuals, those at risk for heart disease, and those with prevalent cardiovascular disorders. The optimal hs-cTn threshold for each circumstance varies by the assay used and by the population assessed. This review will provide context for how hs-cTn assays might be interpreted depending on the application sought, reviewing results from studies leveraging hs-cTn for applications beyond "acute myocardial infarction diagnostic evaluation."

AST/ALT ratio predicts the functional severity of chronic heart failure with reduced left ventricular ejection fraction

Objective

Despite previous research that focused on liver transaminases as predictors of cardiovascular disease, there has been limited research evaluating the predictive value of AST/ALT ratio in patients with heart failure. We aimed to investigate AST/ALT ratio as an indicator of the functional severity in chronic heart failure with reduced left ventricular ejection fraction.

Results

Overall, 105 patients previously diagnosed with HFrEF from Buraidah-Al Qassim province, Saudi Arabia were included in this retrospective cross-sectional study. Data on study variables, including demographic data, left ventricular ejection fraction, NYHA class, and AST/ALT ratio, were collected from patients’ records. The patients were divided into two groups, namely group-1 (AST/ALT ratio < 1) and group-2 (AST/ALT ratio ≥ 1), to identify any differences in their cardiac function profiles. NYHA class and NT-proBNP were higher and LVEF was lower in group-2 than in group-1. We found a mild significant correlation between AST/ALT ratio and APRI, FIB-4 score, NYHA-class, and LVEF (r = 0.2, 0.25, 0.26, and − 0.24, respectively; P < 0.05). Multivariate linear regression analysis model and ROC curve showed that AST/ALT ratio could independently predict HFrEF functional severity with a best cut-off value of 0.9, sensitivity of 43.6%, and specificity of 81.4%.

Use of Cardiac Biomarkers for Monitoring Improvement of Left Ventricular Function by Immunoadsorption Treatment in Dilated Cardiomyopathy

Immunoadsorption and subsequent administration of intravenous immunoglobulin (IVIG) have shown beneficial effects on cardiac function and symptoms in patients with dilated cardiomyopathy. Biomarkers play an emerging role in disease monitoring and outcome prediction of heart failure (HF) patients. We aimed to analyze cardiac biomarkers as predictor for improvement of left ventricular (LV) function after immunoadsorption treatment in dilated cardiomyopathy (DCM). Thirty-one patients with dilated cardiomyopathy on optimized HF pharmacotherapy received a single cycle of immunoadsorption for five days followed by IVIG administration. Left ventricular ejection fraction (LVEF) and heart failure biomarkers (hs troponin T, hs troponin I, NT-proBNP and sST2) were evaluated before treatment, after the last cycle of immunoadsorption and during a median follow-up of 30.5 months. We correlated HF biomarkers before immunoadsorption and acute changes of HF biomarkers by immunoadsorption with LV improvement during the long-term follow-up. LV function improved significantly after immunoadsorption from 28.0 to 42.0% during the long-term follow-up (p < 0.0001). Evaluation of biomarker levels showed a significant decrease for hs troponin I (from 9.2 to 5.5 ng/L, p < 0.05) and NT-proBNP (from 789.6 to 281.2 pg/mL, p < 0.005). Correlation of biomarker levels before immunoadsorption and LVEF at the long-term follow-up show good results for hs troponin T (r = −0.40, r² = 0.16, p < 0.05), hs troponin I (r = −0.41, r² = 0.17, p < 0.05) and sST2 (r = −0.46, r² = 0.19, p < 0.05). Correlation of biomarker levels before immunoadsorption and the individual increase in LV function was significant for hs troponin T (r = −0.52, r² = 0.27, p < 0.005) and hs troponin I (r = −0.53, r² = 0.29, p < 0.005). To imply a tool for monitoring outcome immediately after immunoadsorption treatment, we investigated the correlation of acute changes of biomarker levels by immunoadsorption treatment and individual increase in LV function. A drop in hs troponin T (r = −0.41, r² = 0.17, p < 0.05) and hs troponin I (r = −0.53, r² = 0.28, p < 0.005) levels demonstrate a good correlation to improvement in LVEF during the long-term follow-up. Conclusion: Hs troponin T and I levels correlate with LV function improvement during long-term follow-up. Acute decrease of troponins by immunoadsorption treatment is paralleled by individual improvement of LVEF at the long-term follow-up. Thus, troponins could serve as a monitoring tool for the improvement of LV function after immunoadsorption treatment in dilated cardiomyopathy.

Established and Emerging Roles of Biomarkers in Heart Failure

Heart failure (HF) is a complex syndrome with an enormous societal burden in terms of cost, morbidity, and mortality. Natriuretic peptide testing is now widely used to support diagnosis, prognostication, and management of patients with HF and are incorporated into HF clinical practice guidelines. Beyond the natriuretic peptides, novel biomarkers may supplement traditional clinical and laboratory testing to improve understanding of the complex disease process of HF and possibly to personalize care for those affected through better individual phenotyping. In this review, we will discuss natriuretic peptides and the more novel biomarkers by dividing them into categories based on the major pathophysiologic pathways they represent. Given the complex physiology in HF, it is reasonable to expect that the future of biomarker testing lies in the application of multimarker testing panels, precision medicine to improve HF care delivery, and the use of biomarkers in proteomics and metabolomics to further improve HF care.

sST2 Predicts Outcome in Chronic Heart Failure Beyond NT-proBNP and High-Sensitivity Troponin T

BACKGROUND

Soluble suppression of tumorigenesis-2 (sST2) is a biomarker related to inflammation and fibrosis.

OBJECTIVES

This study assessed the independent prognostic value of sST2 in chronic heart failure (HF).

METHODS

Individual patient data from studies that assessed sST2 for risk prediction in chronic HF, together with N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (hs-TnT), were retrieved.

RESULTS

A total of 4,268 patients were evaluated (median age 68 years, 75% males, 65% with ischemic HF, 87% with left ventricular ejection fraction [LVEF] <40%). NT-proBNP, hs-TnT, and sST2 were 1,360 ng/l (interquartile interval: 513 to 3,222 ng/l), 18 ng/l (interquartile interval: 9 to 33 ng/l), and 27 ng/l (interquartile interval: 20 to 39 ng/l), respectively. During a 2.4-year median follow-up, 1,319 patients (31%) experienced all-cause death (n = 932 [22%] for cardiovascular causes). Among the 4,118 patients (96%) with available data, 1,029 (24%) were hospitalized at least once for worsening HF over 2.2 years. The best sST2 cutoff for the prediction of all-cause and cardiovascular death and HF hospitalization was 28 ng/ml, with good performance at Kaplan-Meier analysis (log-rank: 117.6, 61.0, and 88.6, respectively; all p < 0.001). In a model that included age, sex, body mass index, ischemic etiology, LVEF, New York Heart Association functional class, glomerular filtration rate, HF medical therapy, NT-proBNP, and hs-TnT, the risk of all-cause death, cardiovascular death, and HF hospitalization increased by 26%, 25%, and 30%, respectively, per each doubling of sST2. sST2 retained its independent prognostic value across most population subgroups.

CONCLUSIONS

sST2 yielded strong, independent predictive value for all-cause and cardiovascular mortality, and HF hospitalization in chronic HF, and deserves consideration to be part of a multimarker panel together with NT-proBNP and hs-TnT.

Imaging, Biomarker, and Clinical Predictors of Cardiac Remodeling in Heart Failure With Reduced Ejection Fraction

In response to injury, hemodynamic changes, or neurohormonal activation, the heart undergoes a series of structural and functional changes that have been termed cardiac remodeling. Remodeling is defined as changes in cardiac geometry and/or function over time and can be measured in terms of changes in cardiac chamber dimensions, wall thickness, volumes, mass, and ejection fraction at serial imaging examinations. As to cardiac chambers, left ventricular (LV) remodeling has been best studied in patients with heart failure with reduced ejection fraction. Although LV remodeling may compensate for abnormal hemodynamic parameters and function in the short term, left unchecked, it is associated with worsening cardiac function and poor prognosis. On the other hand, reversing LV geometry and/or function closer to that of a normal heart (also known as reverse remodeling) is associated with improved cardiac function and better prognosis. Because of its close relationship with clinical outcomes, remodeling may potentially be targeted in clinical management and used in trials as a surrogate endpoint. Standardized definition of remodeling and reliable tools to predict and monitor the presence, direction, and magnitude of cardiac remodeling are needed. Together with clinical and imaging findings, circulating biomarkers (most notably N-terminal pro-B-type natriuretic peptide, high-sensitivity troponin, and soluble suppression of tumorigenesis-2) may be helpful in this respect.

MicroRNAs Associated With Reverse Left Ventricular Remodeling in Humans Identify Pathways of Heart Failure Progression

BACKGROUND

Plasma extracellular RNAs have recently garnered interest as biomarkers in heart failure (HF). Most studies in HF focus on single extracellular RNAs related to phenotypes and outcomes, and few describe their functional roles. We hypothesized that clusters of plasma microRNAs (miRNAs) associated with left ventricular (LV) remodeling in human HF would identify novel subsets of genes involved in HF in animal models.

METHODS AND RESULTS

We prospectively measured circulating miRNAs in 64 patients with systolic HF (mean age, 64.8 years; 91% men; median LV ejection fraction, 26%) with serial echocardiography (10 months apart) during medical therapy. We defined LV reverse remodeling as a 15% reduction in LV end-systolic volume index. Using principal components analysis, we identified a component associated with LV reverse remodeling (odds ratio=3.99; P=0.01) that provided risk discrimination for LV reverse remodeling superior to a clinical model (C statistic, 0.58 for a clinical model versus 0.71 for RNA-based model). Using network bioinformatics, we uncovered genes not previously widely described in HF regulated simultaneously by >2 miRNAs. We observed increased myocardial expression of these miRNAs during HF development in animals, with downregulation of target gene expression, suggesting coordinate miRNA-mRNA regulation. Target mRNAs were involved in autophagy, metabolism, and inflammation.

CONCLUSIONS

Plasma miRNAs associated with LV reverse remodeling in humans are dysregulated in animal HF and target clusters of genes involved in mechanisms implicated in HF. A translational approach integrating human HF, bioinformatics, and model systems may uncover novel pathways involved in HF.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00351390.

Recommendations for Institutions Transitioning to High-Sensitivity Troponin Testing: JACC Scientific Expert Panel

High-sensitivity cardiac troponin (hs-cTn) I or T methods have been in use in certain regions for years but are now increasingly globally adopted, including in the United States. Accordingly, inevitable challenges are created for institutions transitioning from conventional cardiac troponin (cTn) assays. hs-cTn assays have higher analytic precision at lower concentrations, yielding greater clinical sensitivity for myocardial injury and allowing accurate recognition of small changes in troponin concentration (rise or fall) within a short time frame. Although much of the knowledge regarding troponin biology that was applicable with older troponin assays still holds true, considerable education regarding the differences between conventional cTn and hs-cTn is needed before medical systems convert to the newer methods. This includes a basic understanding of how hs-cTn testing differs from conventional cTn testing and how it is best deployed in different settings, such as the emergency department and inpatient services. This Expert Panel will review important concepts for institutional transition to hs-cTn methodology, providing recommendations useful for education before implementation.

Rationale and methods of the Prospective Study of Biomarkers, Symptom Improvement, and Ventricular Remodeling During Sacubitril/Valsartan Therapy for Heart Failure (PROVE-HF)

BACKGROUND

Sacubitril/valsartan is an angiotensin receptor-neprilysin inhibitor indicated for the treatment of patients with chronic heart failure (HF) with reduced ejection fraction; however, its mechanism of benefit remains unclear. Biomarkers that are linked to ventricular remodeling, myocardial injury, and fibrosis may provide mechanistic insight and important clinical guidance regarding sacubitril/valsartan use.

METHODS

This 52-week, multicenter, open-label, single-arm study is designed to (1) correlate biomarker changes with cardiac remodeling parameters, cardiovascular outcomes, and patient-reported outcome data and (2) determine short- and long-term changes in concentrations of biomarkers related to potential mechanisms of action and effects of sacubitril/valsartan therapy. Approximately 830 patients with HF with reduced ejection fraction will be initiated and titrated on sacubitril/valsartan according to United States prescribing information. Primary efficacy end points include the changes in N-terminal pro-B-type natriuretic peptide concentrations and cardiac remodeling from baseline to 1 year. Secondary end points include changes in concentrations of N-terminal pro-B-type natriuretic peptide and remodeling to 6 months, and changes in patient-reported outcomes using the Kansas City Cardiomyopathy Questionnaire-23 from baseline to 1 year. In addition, several other relevant biomarkers will be measured. Biomarker changes relative to the number of cardiovascular events in 12 months will also be assessed as exploratory end points.

CONCLUSIONS

Results from the Prospective Study of Biomarkers, Symptom Improvement, and Ventricular Remodeling During Sacubitril/Valsartan Therapy for Heart Failure (PROVE-HF) will help establish a mechanistic understanding of angiotensin receptor-neprilysin inhibitor therapeutic benefits and provide clinicians with clarity on how to interpret information on biomarkers during treatment (PROVE-HF ClinicalTrials.gov identifier: NCT02887183).

Novel Biomarkers for the Risk Stratification of Heart Failure with Preserved Ejection Fraction

PURPOSE OF REVIEW

The use of biomarkers in heart failure (HF) is a rapidly changing field. The purpose of this review is to assess the current evidence of the use of biomarkers for risk stratification in patients with HF with preserved ejection fraction (HFpEF).

RECENT FINDINGS

Despite differences in pathophysiology between HF with reduced ejection fraction and HFpEF, traditional HF biomarkers such as brain natriuretic peptide and troponin retain prognostic value in most HFpEF-specific populations. Biomarkers of key pathophysiologic components of HFpEF, such as myocardial fibrosis, remodeling, and systemic inflammation are also valuable prognostic markers. Further investigation into HF biomarkers may identify significant therapeutic targets for the treatment of HFpEF.

Prognostic Value of High-Sensitivity Troponin T in Chronic Heart Failure

Background:

Most patients with chronic heart failure have detectable troponin concentrations when evaluated by high-sensitivity assays. The prognostic relevance of this finding has not been clearly established so far. We aimed to assess high-sensitivity troponin assay for risk stratification in chronic heart failure through a meta-analysis approach.

Methods:

Medline, EMBASE, Cochrane Library, and Scopus were searched in April 2017 by 2 independent authors. The terms were “troponin” AND “heart failure” OR “cardiac failure” OR “cardiac dysfunction” OR “cardiac insufficiency” OR “left ventricular dysfunction.” Inclusion criteria were English language, clinical stability, use of a high-sensitivity troponin assay, follow-up studies, and availability of individual patient data after request to authors. Data retrieved from articles and provided by authors were used in agreement with the PRISMA statement. The end points were all-cause death, cardiovascular death, and hospitalization for cardiovascular cause.

Results:

Ten studies were included, reporting data on 11 cohorts and 9289 patients (age 66±12 years, 77% men, 60% ischemic heart failure, 85% with left ventricular ejection fraction <40%). High-sensitivity troponin T data were available for all patients, whereas only 209 patients also had high-sensitivity troponin I assayed. When added to a prognostic model including established risk markers (sex, age, ischemic versus nonischemic etiology, left ventricular ejection fraction, estimated glomerular filtration rate, and N-terminal fraction of pro-B-type natriuretic peptide), high-sensitivity troponin T remained independently associated with all-cause mortality (hazard ratio, 1.48; 95% confidence interval, 1.41–1.55), cardiovascular mortality (hazard ratio, 1.40; 95% confidence interval, 1.33–1.48), and cardiovascular hospitalization (hazard ratio, 1.42; 95% confidence interval, 1.36–1.49), over a median 2.4-year follow-up (all P <0.001). High-sensitivity troponin T significantly improved risk prediction when added to a prognostic model including the variables above. It also displayed an independent prognostic value for all outcomes in almost all population subgroups. The area under the curve–derived 18 ng/L cutoff yielded independent prognostic value for the 3 end points in both men and women, patients with either ischemic or nonischemic etiology, and across categories of renal dysfunction.

Conclusions:

In chronic heart failure, high-sensitivity troponin T is a strong and independent predictor of all-cause and cardiovascular mortality, and of hospitalization for cardiovascular causes, as well. This biomarker then represents an additional tool for prognostic stratification.

Serial Heart Rates, Guideline-Directed Beta Blocker Use, and Outcomes in Patients With Chronic Heart Failure With Reduced Ejection Fraction

A single heart rate (HR) measurement may inform future prognosis in chronic heart failure with reduced ejection fraction (HFrEF). The importance of elevated HR across serial assessment is uncertain, particularly with well-applied guideline-directed medical therapy (GDMT) with beta blockers (BBs). In this post hoc analysis of 129 patients with chronic HFrEF in sinus rhythm, who had aggressive medication titration over 10.6 months, HR and BB use were assessed at each visit (average of 6 visits per patient). All-cause mortality was assessed. At baseline, 81 subjects (62.8%) had HR ≥70 beats/min; 40 subjects (31.0%) had high HR despite being on ≥50% of GDMT BB dose. At final visit, 30.4% of the subjects still had high HR despite achieving ≥50% target BB dose. There were no significant baseline differences in demographics or BB doses in patients with HR <70 vs HR ≥70 beats/min. In adjusted model in which HR was treated as time-dependent covariate, an increase in HR of 10  beats/min was associated with an increased hazard of all-cause mortality during follow-up (adjusted hazard ratio per 10 beats/min = 2.46; 95% confidence interval 1.46-4.16, p <0.001). In conclusion, in well-managed patients with HFrEF, high HR was frequent even after aggressive medication titration, and often despite being on at least 50% of GDMT BB dose. An increase in HR was associated with worse clinical outcomes (Clinicaltrials.gov NCT#00351390).

Beyond Natriuretic Peptides for Diagnosis and Management of Heart Failure

BACKGROUND

Heart failure (HF) is a complex syndrome with an enormous societal burden in terms of cost and morbidity and mortality. Natriuretic peptide (NP) testing is now widely used to support diagnosis, prognostication, and management of patients with HF, but NPs come with limitations, including vulnerability to the presence of obesity, atrial fibrillation, and renal dysfunction, for example. Beyond the NPs, novel biomarkers may supplement traditional clinical and laboratory testing to improve understanding of the complex disease process of HF, and possibly to personalize care for those affected through better individual phenotyping.

CONTENT

In this review we discuss novel biomarkers by dividing them into categories based on major pathophysiologic pathways they represent including myocardial stretch/stress, cardiac extracellular matrix remodeling, cardiomyocyte injury/death, oxidative stress, inflammation, neurohumoral activation, and renal dysfunction.

SUMMARY

Given the limitations of NPs, along with the complex physiology in HF, it is logical to consider utilization of novel biomarkers providing orthogonal biological and clinical information. Several novel HF biomarkers have shown promise but have substantial expectations to meet before being used clinically. Nonetheless, it is reasonable to expect the future lies in the application of multibiomarker panels for the improvement in management of HF and the personalization of care.

Dynamic Changes in High-Sensitivity Cardiac Troponin I Are Associated with Dynamic Changes in Sum Absolute QRST Integral on Surface Electrocardiogram in Acute Decompensated Heart Failure

BACKGROUND

A three-dimensional electrocardiographic (ECG) metric, the sum absolute QRST integral (SAI QRST), predicts ventricular arrhythmias in heart failure (HF) patients with implantable cardioverter defibrillator and mechanical response to cardiac resynchronization therapy. We hypothesized that there is an association between patient-specific changes in SAI QRST and myocardial injury as measured by high-sensitivity troponin I (hsTnI).

METHODS

Sum absolute integral QRST on resting 12-lead ECG and hsTnI were measured simultaneously, every 3 hours, and during 12-hour observation period in a prospective cohort of emergency department patients (n = 398; mean age 57.8 ± 13.2 years; 54% female, 64% black), diagnosed with acute coronary syndrome (ACS, n = 28), acutely decompensated HF (acute decompensated heart failure, n = 35), cardiac non-ACS (n = 19), or noncardiac condition (n = 316). Random-effects linear regression analysis assessed the association of SAI QRST and myocardial injury, with adjustment for demographics (age, sex, race), prevalent cardiovascular disease (myocardial infarction, history of revascularization, stroke, and HF), risk factors (diabetes, smoking, hypercholesterolemia, hypertension, and cocaine use), and left bundle branch block.

RESULTS

Within the entire cohort, SAI QRST decreased by 3 (95%CI -5 to -1) mV*ms every 3 hours. A 10-fold increase in hsTnI was associated with a 7.7 (0.6-14.9) mV*ms increase in SAI QRST. In the subgroup of acutely decompensated HF patients (n = 35), a 10-fold increase in hsTnI was associated with a 61.0 (5.9-116.1) mV*ms increase in SAI QRST.

CONCLUSION

Patient-specific time-varying changes in the surface ECG scalar measure of global electrical heterogeneity, as measured by SAI QRST, and in myocardial injury as measured by hsTnI, are independently and directly associated with each other, likely reflecting a common underlying mechanism.

Novel Heart Failure Biomarkers Predict Improvement of Mitral Regurgitation in Patients Receiving Cardiac Resynchronization Therapy-The BIOCRT Study

BACKGROUND

Cardiac resynchronization therapy (CRT) improves mitral regurgitation (MR) in a subset of patients. We hypothesized that biomarkers (amino-terminal pro-B type natriuretic peptide, high-sensitivity troponin I, galectin-3 [gal-3], and soluble ST2) might predict MR response after CRT.

METHODS

We measured levels of biomarkers during CRT implantation in 132 patients with a subsequent 2-year follow-up. MR was graded as no-trace, mild, moderate, or severe at baseline and at 6 months.

RESULTS

In patients with baseline at least mild MR, 56% had improvement at 6 months, with lower 2-year mortality vs patients without improvement (0% vs 18%; P = 0.002). At baseline, patients with MR improvement had lower high-sensitivity troponin I and gal-3 levels compared with those without improvement (19 vs 40 pg/L; P = 0.01; 14 vs 18 ng/mL; P = 0.007). In multivariable analyses, higher log-transformed gal-3 (odds ratio, 0.15; 95% confidence interval, 0.04-0.65; P = 0.01) remained an independent predictor for MR nonimprovement. Levels of pro-B type natriuretic peptide and soluble ST2 were lower at follow-up in patients with MR improvement (potentially reflecting reduced myocardial stretch and stress) without reaching statistical significance.

CONCLUSIONS

Higher galectin levels at the time of CRT implantation are associated with MR nonresponse.

The Current and Potential Clinical Relevance of Heart Failure Biomarkers

Heart failure is a growing epidemic, and our understanding of the intricacies of its pathophysiology continues to evolve. Over the last decade, biomarkers of heart failure have been extensively investigated, particularly for diagnosis and risk stratification. While the natriuretic peptides remain the gold standard heart failure biomarker, they are plagued by their non-specific nature; furthermore, the strategy of natriuretic peptide-guided care remains elusive. Multiple candidate markers indicative of other physiologic aspects of heart failure have been identified and studied, including soluble ST2, galectin-3, and high-sensitivity cardiac troponins. Each of these biomarkers has the potential to provide unique therapeutically relevant information. Ultimately, a multi-marker approach may be applied to improve care of patients with heart failure. Definitive clinical trials and the use of advanced statistical analytic techniques are needed to truly determine the optimal strategy of biomarker-assisted diagnosis, prognostication, and management of patients who suffer from this devastating condition.

Partial Adenosine A1 Agonist in Heart Failure

Adenosine exerts a variety of physiological effects by binding to cell surface G-protein-coupled receptor subtypes, namely, A1, A2a, A2b, and A3. The central physiological role of adenosine is to preclude tissue injury and promote repair in response to stress. In the heart, adenosine acts as a cytoprotective modulator, linking cardiac function to metabolic demand predominantly via activation of adenosine A1 receptors (A1Rs), which leads to inhibition of adenylate cyclase activity, modulation of protein kinase C, and opening of ATP-sensitive potassium channels. Activation of myocardial adenosine A1Rs has been shown to modulate a variety of pathologies associated with ischemic cardiac injury, including arrhythmogenesis, coronary and ventricular dysfunction, apoptosis, mitochondrial dysfunction, and ventricular remodeling. Partial A1R agonists are agents that are likely to elicit favorable pharmacological responses in heart failure (HF) without giving rise to the undesirable cardiac and extra-cardiac effects observed with full A1R agonism. Preclinical data have shown that partial adenosine A1R agonists protect and improve cardiac function at doses that do not result in undesirable effects on heart rate, atrioventricular conduction, and blood pressure, suggesting that these compounds may constitute a valuable new therapy for chronic HF. Neladenoson bialanate (BAY1067197) is the first oral partial and highly selective A1R agonist that has entered clinical development for the treatment of HF. This review provides an overview of adenosine A1R-mediated signaling in the heart, summarizes the results from preclinical and clinical studies of partial A1R agonists in HF, and discusses the potential benefits of these drugs in the clinical setting.