Combined use of the novel biomarkers high-sensitivity troponin T and ST2 for heart failure risk stratification vs conventional assessment

Biomarkers in Heart Failure with Preserved Ejection Fraction: A Perpetually Evolving Frontier

Heart failure with preserved ejection fraction (HFpEF) represents a complex clinical syndrome, often very difficult to diagnose using the available tools. As the global burden of this disease is constantly growing, surpassing the prevalence of heart failure with reduced ejection fraction, during the last few years, efforts have focused on optimizing the diagnostic and prognostic pathways using an immense panel of circulating biomarkers. After the paradigm of HFpEF development emerged more than 10 years ago, suggesting the impact of multiple comorbidities on myocardial structure and function, several phenotypes of HFpEF have been characterized, with an attempt to find an ideal biomarker for each distinct pathophysiological pathway. Acknowledging the limitations of natriuretic peptides, hundreds of potential biomarkers have been evaluated, some of them demonstrating encouraging results. Among these, soluble suppression of tumorigenesis-2 reflecting myocardial remodeling, growth differentiation factor 15 as a marker of inflammation and albuminuria as a result of kidney dysfunction or, more recently, several circulating microRNAs have proved their incremental value. As the number of emerging biomarkers in HFpEF is rapidly expanding, in this review, we aim to explore the most promising available biomarkers linked to key pathophysiological mechanisms in HFpEF, outlining their utility for diagnosis, risk stratification and population screening, as well as their limitations.

Soluble ST2: A Novel Biomarker for Diagnosis and Prognosis of Cardiovascular Disease

The increasing incidence of cardiovascular disease (CVD) is a significant global health concern, affecting millions of individuals each year. Accurate diagnosis of acute CVD poses a formidable challenge, as misdiagnosis can significantly decrease patient survival rates. Traditional biomarkers have played a vital role in the diagnosis and prognosis of CVDs, but they can be influenced by various factors, such as age, sex, and renal function. Soluble ST2 (sST2) is a novel biomarker that is closely associated with different CVDs. Its low reference change value makes it suitable for continuous measurement, unaffected by age, kidney function, and other confounding factors, facilitating risk stratification of CVDs. Furthermore, the combination of sST2 with other biomarkers can enhance diagnostic accuracy and prognostic value. This review aims to provide a comprehensive overview of sST2, focusing on its diagnostic and prognostic value as a myocardial marker for different types of CVDs and discussing the current limitations of sST2.

Comprehensive Quality Analysis of Conventional and Novel Biomarkers in Diagnosing and Predicting Prognosis of Coronary Artery Disease, Acute Coronary Syndrome, and Heart Failure, a Comprehensive Literature Review

Coronary artery disease (CAD), acute coronary syndrome (ACS), and heart failure (HF) are major global health issues with high morbidity and mortality rates. Biomarkers like cardiac troponins (cTn) and natriuretic peptides (NPs) are crucial tools in cardiology, but numerous new biomarkers have emerged, proving increasingly valuable in CAD/ACS. These biomarkers are classified based on their mechanisms, such as fibrosis, metabolism, inflammation, and congestion. The integration of established and emerging biomarkers into clinical practice is an ongoing process, and recognizing their strengths and limitations is crucial for their accurate interpretation, incorporation into clinical settings, and improved management of CVD patients. We explored established biomarkers like cTn, NPs, and CRP, alongside newer biomarkers such as Apo-A1, IL-17E, IgA, Gal-3, sST2, GDF-15, MPO, H-FABP, Lp-PLA2, and ncRNAs; provided evidence of their utility in CAD/ACS diagnosis and prognosis; and empowered clinicians to confidently integrate these biomarkers into clinical practice based on solid evidence.

High-sensitivity Troponin (hs-Tn) for Cardiovascular Risk Prognostication: A Systematic Review and Meta-analysis

BACKGROUND

Chronic low-grade inflammation is involved in coronary atherosclerosis progression whereas recent research efforts suggest that preventative methods should be tailored to the "residual inflammatory risk". As such, modalities for the early identification of the risk have to be investigated.

METHODS

We performed a systematic review and meta-analysis according to the PRISMA guidelines. Any study that presented the prognostic value of high sensitivity troponin (hs-cTn) of vascular inflammation in stable patients without known cardiac heart disease was considered to be potentially eligible. The Medline (PubMed) database was searched up to April 22, 2021. The main endpoint was the difference in c-index (Δ[c-index]) with the use of hs-cTn for major adverse cardiovascular events (MACEs), cardiovascular and all-cause mortality. We calculated I2 to test heterogeneity.

RESULTS

In total, 44 studies and 112,288 stable patients without known coronary heart disease were included in this meta-analysis. The mean follow-up duration of the whole cohort was 6.8 ± 1.1 years. 77,004 (68.5%) of the patients presented at low cardiovascular risk while 35,284 (31.5%) in high. The overall pooled estimate of Δ[c-index] for MACE was 1.4% (95%CI: 0.7-2.1, I2=0%) and for cardiovascular death 1.3% (95%CI: 0.3-2.3, I2=0%). Finally, the overall pooled estimate of Δ[c-index] for all-cause mortality was 3% (95%CI: 1.9-3.9, I2=86%), while high heterogeneity was observed between the studies.

CONCLUSION

The predictive usefulness of changes in hs-cTn measures in stable individuals with either high or low cardiovascular risk, demonstrates that assessing vascular inflammation in addition to clinical risk factors enhances risk prediction for cardiovascular events and allcause mortality. Further prospective studies are necessary to confirm these findings and assist clinical decision-making regarding the most optimal prevention strategy.

Prognostic Value of sST2 in Heart Failure

In recent years, there has been growing interest in the risk stratification for heart failure, and the use of multiple biomarkers to identify different pathophysiological processes associated with this condition. One such biomarker is soluble suppression of tumorigenicity-2 (sST2), which has shown some potential for integration into clinical practice. sST2 is produced by both cardiac fibroblasts and cardiomyocytes in response to myocardial stress. Other sources of sST2 are endothelial cells of the aorta and coronary arteries and immune cells such as T cells. Indeed, ST2 is also associated with inflammatory and immune processes. We aimed at reviewing the prognostic value of sST2 in both chronic and acute heart failure. In this setting, we also provide a flowchart about its potential use in clinical practice.

Diagnostic and prognostic biomarkers reflective of cardiac remodelling in diabetes mellitus: A scoping review

AIMS

The aim of this scoping review is to evaluate the current biomarkers used in the assessment of adverse cardiac remodelling in people with diabetes mellitus (DM) and in the diagnosis and prognosis of subsequent cardiovascular disease. We aim to discuss the biomarkers' pathophysiological roles as a reflection of the cardiac remodelling mechanisms in the presence of DM.

METHODS

We performed the literature search to include studies from 2003 to 2021 using the following databases: MEDLINE, Scopus, Web of Science, PubMed, and Cochrane library. Articles that met our inclusion criteria were screened and appraised before being included in this review. The PRISMA guidelines for Scoping Reviews were followed.

RESULTS

Our literature search identified a total of 43 eligible articles, which were included in this scoping review. We identified 15 different biomarkers, each described by at least two studies, that were used to determine signs of cardiac remodelling in cardiovascular disease (CVD) and people with DM. NT-proBNP was identified as the most frequently employed biomarker in this context; however, we also identified emerging biomarkers including hs-CRP, hs-cTnT, and Galectin-3.

CONCLUSION

There is a complex relationship between DM and cardiovascular health, where more research is needed. Current biomarkers reflective of adverse cardiac remodelling in DM are often used to diagnose other CVDs, such as NT-proBNP for heart failure. Hence there is a need for identification of specific biomarkers that can detect early signs of cardiac remodelling in the presence of DM. Further research into these biomarkers and mechanisms can deepen our understanding of their role in DM-associated CVD and lead to better preventative therapies.

Periodic repolarization dynamics as predictor of risk for sudden cardiac death in chronic heart failure patients

The two most common modes of death among chronic heart failure (CHF) patients are sudden cardiac death (SCD) and pump failure death (PFD). Periodic repolarization dynamics (PRD) quantifies low-frequency oscillations in the T wave vector of the electrocardiogram (ECG) and has been postulated to reflect sympathetic modulation of ventricular repolarization. This study aims to evaluate the prognostic value of PRD to predict SCD and PFD in a population of CHF patients. 20-min high-resolution (1000 Hz) ECG recordings from 569 CHF patients were analyzed. Patients were divided into two groups, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {PRD}^+$$\end{document}PRD+ and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {PRD}^-$$\end{document}PRD-, corresponding to PRD values above and below the optimum cutoff point of PRD in the study population. Univariate Cox regression analysis showed that SCD risk in the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {PRD}^+$$\end{document}PRD+ group was double the risk in the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {PRD}^-$$\end{document}PRD- group [hazard ratio (95% CI) 2.001 (1.127–3.554), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {p}<0.05$$\end{document}p<0.05]. The combination of PRD with other Holter-based ECG indices, such as turbulence slope (TS) and index of average alternans (IAA), improved SCD prediction by identifying groups of patients at high SCD risk. PFD could be predicted by PRD only when combined with TS [hazard ratio 2.758 (1.572–4.838), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {p}<0.001$$\end{document}p<0.001]. In conclusion, the combination of PRD with IAA and TS can be used to stratify the risk for SCD and PFD, respectively, in CHF patients.

Biomarkers in AL Amyloidosis

Systemic AL amyloidosis is a rare complex hematological disorder caused by clonal plasma cells which produce amyloidogenic immunoglobulins. Outcome and prognosis is the combinatory result of the extent and pattern of organ involvement secondary to amyloid fibril deposition and the biology and burden of the underlying plasma cell clone. Prognosis, as assessed by overall survival, and early outcomes is determined by degree of cardiac dysfunction and current staging systems are based on biomarkers that reflect the degree of cardiac damage. The risk of progression to end-stage renal disease requiring dialysis is assessed by renal staging systems. Longer-term survival and response to treatment is affected by markers of the underlying plasma cell clone; the genetic background of the clonal disease as evaluated by interphase fluorescence in situ hybridization in particular has predictive value and may guide treatment selection. Free light chain assessment forms the basis of hematological response criteria and minimal residual disease as assessed by sensitive methods is gradually being incorporated into clinical practice. However, sensitive biomarkers that could aid in the early diagnosis and that could reflect all aspects of organ damage and disease biology are needed and efforts to identify them are continuous.

Meteorin-like/Meteorin-β protects heart against cardiac dysfunction

Meteorin-like/Meteorin-β (Metrnl/Metrnβ) is a secreted protein produced by skeletal muscle and adipose tissue that exerts metabolic actions that improve glucose metabolism. The role of Metrnβ in cardiac disease is completely unknown. Here, we show that Metrnβ-null mice exhibit asymmetrical cardiac hypertrophy, fibrosis, and enhanced signs of cardiac dysfunction in response to isoproterenol-induced cardiac hypertrophy and aging. Conversely, adeno-associated virus-mediated specific overexpression of Metrnβ in the heart prevents the development of cardiac remodeling. Furthermore, Metrnβ inhibits cardiac hypertrophy development in cardiomyocytes in vitro, indicating a direct effect on cardiac cells. Antibody-mediated blockage of Metrnβ in cardiomyocyte cell cultures indicated an autocrine action of Metrnβ on the heart, in addition to an endocrine action. Moreover, Metrnβ is highly produced in the heart, and analysis of circulating Metrnβ concentrations in a large cohort of patients reveals that it is a new biomarker of heart failure with an independent prognostic value.

Combining Novel Biomarkers for Risk Stratification of Two-Year Cardiovascular Mortality in Patients with ST-Elevation Myocardial Infarction

ST-elevation myocardial infarction (STEMI) is one of the main reasons for morbidity and mortality worldwide. In addition to the classic biomarker NT-proBNP, new biomarkers like ST2 and Pentraxin-3 (Ptx-3) have emerged as potential tools in stratifying risk in cardiac patients. Indeed, multimarker approaches to estimate prognosis of STEMI patients have been proposed and their potential clinical impact requires investigation. In our study, in 147 patients with STEMI, NT-proBNP as well as serum levels of ST2 and Ptx-3 were evaluated. During two-year follow-up (FU; 734.2 ± 61.2 d) results were correlated with risk for cardiovascular mortality (CV-mortality). NT-proBNP (HR = 1.64, 95% CI = 1.21–2.21, p = 0.001) but also ST2 (HR = 1.000022, 95% CI = 1.00–1.001, p < 0.001) were shown to be reliable predictors of CV-mortality, while the highest predictive power was observed with Ptx-3 (HR = 3.1, 95% CI = 1.63–5.39, p < 0.001). When two biomarkers were combined in a multivariate Cox regression model, relevant improvement of risk assessment was only observed with NT-proBNP+Ptx-3 (AIC = 209, BIC = 214, p = 0.001, MER = 0.75, MEV = 0.64). However, the highest accuracy was seen using a three-marker approach (NT-proBNP + ST2 + Ptx-3: AIC = 208, BIC = 214, p < 0.001, MER = 0.77, MEV = 0.66). In conclusion, after STEMI, ST2 and Ptx-3 in addition to NT-proBNP were associated with the incidence of CV-mortality, with multimarker approaches enhancing the accuracy of prediction of CV-mortality.

Cardiorenal interaction and heart failure outcomes. A role for insulin-like growth factor binding protein 2?

INTRODUCTION AND OBJECTIVES

Preliminary results suggest that high circulating insulin-like growth factor binding protein 2 (IGFBP2) levels are associated with mortality risk in heart failure (HF) patients. As IGFBP2 levels are increased in patients with chronic kidney disease (CKD), which is associated with a higher mortality risk in HF patients, we examined whether IGFBP2 is associated with CKD in HF patients, and whether CKD modifies the prognostic value of this protein in HF patients.

METHODS

HF patients (n=686, mean age 66.6 years, 32.7% women) were enrolled and followed up for a median of 3.5 (min-max range: 0.1-6) years. Patients were classified as having CKD with decreased estimated glomerular filtration rate (eGFR <60mL/min/1.73 m²) or as having CKD with nondecreased eGFR (≥ 60mL/min/1.73 m²). Serum IGFBP2 was detected by ELISA.

RESULTS

IGFBP2 was increased (P <.001) in CKD patients with decreased eGFR (n=290, 42.3%) compared with patients with nondecreased eGFR. IGFBP2 was directly associated with NT-proBNP (P <.001) and inversely associated with eGFR (P <.001), with both associations being independent of confounding factors. IGFBP2 was directly and independently associated with cardiovascular and all-cause death (P <.001) in the whole group of patients, but showed a stronger association with cardiovascular death in CKD patients with decreased eGFR (P for interaction <.05), improving risk prediction in these patients over clinically relevant risk factors.

CONCLUSIONS

Serum IGFBP2 is associated with impaired renal function and prognosticates cardiovascular death in patients with HF and CKD with decreased eGFR. Thus, there is an effect modification of CKD on circulating IGFBP2 and on its association with cardiovascular mortality in HF patients.

A bio-clinical approach for prediction of sudden cardiac death in outpatients with heart failure: The ST2-SCD score

BACKGROUND

Sudden cardiac death (SCD) is one of the main modes of death in heart failure (HF) patients and its prediction remains a real challenge. Our aim was to assess the incidence of SCD at 5 years HF contemporary managed outpatients, and to find a simple prediction model for SCD.

METHODS

SCD was considered any unexpected death, witnessed or not, occurring in a previously stable patient with no evidence of worsening HF or any other cause of death. A competing risk strategy was adopted using the Fine-Gray method of Cox regressions analyses that considered other causes of death as the competing event.

RESULTS

The derivation cohort included 744 consecutive outpatients (72% men, age 67.9 ± 12.2 years, left ventricular ejection fraction [LVEF] 36% ± 14). During follow-up, 312 deaths occurred, 40 SCDs (5.4%). Age, haemoglobin, eGFR, HF duration, high-sensitivity troponin T, NTproBNP, and ST2 were associated with SCD in univariate analyses; HF duration (p = 0.006), eGFR (p < 0.001), LVEF <45% (p = 0.03), and ST2 (p = 0.006) remained in multivariable analysis. A predictive score (ST2-SCD) including dichotomous variables (ST2 > 45, LVEF <45%, HF duration >3 years, eGFR < 55, age ≥ 60 years and male sex) provided a Harrell's C-statistic of 0.82 (0.76-0.89)), reaching 0.87 (0.80-0.95) in the validation cohort (n = 149).

CONCLUSIONS

In contemporary managed HF, SCD occurred in 5.4% of outpatients, accounting for 12.8% of all deaths at 5 years. Of the 3 studied biomarkers, only ST2 remained independently associated with SCD. A model containing age, sex, ST2, eGFR, LVEF, and HF duration reasonably predicted 5-years risk of SCD.

Predictive biomarkers for death and rehospitalization in comorbid frail elderly heart failure patients

Background

Heart failure (HF) is associated with a high rate of readmissions within 30 days post-discharge and in the following year, especially in frail elderly patients. Biomarker data are scarce in this high-risk population. This study assessed the value of early post-discharge circulating levels of ST2, NT-proBNP, CA125, and hs-TnI for predicting 30-day and 1-year outcomes in comorbid frail elderly patients with HF with mainly preserved ejection fraction (HFpEF).

Methods

Blood samples were obtained at the first visit shortly after discharge (4.9 ± 2 days). The primary endpoint was the composite of all-cause mortality or HF-related rehospitalization at 30 days and at 1 year. All-cause mortality alone at one year was also a major endpoint. HF-related rehospitalizations alone were secondary end-points.

Results

From February 2014 to November 2016, 522 consecutive patients attending the STOP-HF Clinic were included (57.1% women, age 82 ± 8.7 years, mean Barthel index 70 ± 25, mean Charlson comorbidity index 5.6 ± 2.2). The composite endpoint occurred in 8.6% patients at 30 days and in 38.5% at 1 year. In multivariable analysis, ST2 [hazard ratio (HR) 1.53; 95% CI 1.19–1.97; p = 0.001] was the only predictive biomarker at 30 days; at 1 year, both ST2 (HR 1.34; 95% CI 1.15–1.56; p < 0.001) and NT-proBNP (HR 1.19; 95% CI 1.02–1.40; p = 0.03) remained significant. The addition of ST2 and NT-proBNP into a clinical predictive model increased the AUC from 0.70 to 0.75 at 30 days (p = 0.02) and from 0.71 to 0.74 at 1 year (p < 0.05). For all-cause death at 1 year, ST2 (HR 1.50; 95% CI 1.26–1.80; p < 0.001), and CA125 (HR 1.41; 95% CI 1.21–1.63; p < 0.001) remained independent predictors in multivariable analysis. The addition of ST2 and CA125 into a clinical predictive model increased the AUC from 0.74 to 0.78 (p = 0.03). For HF-related hospitalizations, ST2 was the only predictive biomarker in multivariable analyses, both at 30 days and at 1 year.

Conclusions

In a comorbid frail elderly population with HFpEF, ST2 outperformed NT-proBNP for predicting the risk of all-cause mortality or HF-related rehospitalization. ST2, a surrogate marker of inflammation and fibrosis, may be a better predictive marker in high-risk HFpEF.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0807-2) contains supplementary material, which is available to authorized users.

Prognostic value of circulating microRNAs on heart failure-related morbidity and mortality in two large diverse cohorts of general heart failure patients

AIMS

Small studies suggested circulating microRNAs (miRNAs) as biomarkers for heart failure (HF). However, standardized approaches and quality assessment for measuring circulating miRNAs are not uniformly established, and most studies have been small, so that results are inconsistent. We used a standardized data handling protocol, optimized for circulating miRNA qPCRs to remove noise and used it to assess which circulating miRNAs robustly add prognostic information in patients with HF.

METHODS AND RESULTS

We measured 12 miRNAs in two independent cohorts totalling 2203 subjects. Cohort I (Barcelona) comprised 834 chronic HF patients. Cohort II (Detroit) comprised 1369 chronic HF patients. Each sample was measured in duplicate, and normalized to a very abundant and stable miRNA (miR-486-5p). We used a multistep algorithm to distinguish false amplification signals and thus classify each miRNA measurement as 'valid', 'undetectable' or 'invalid'. Higher levels of miR-1254 and miR-1306-5p were significantly associated with risk of the combined endpoint of all-cause mortality and HF hospitalization in both cohorts, with hazard ratios ranging from 1.11 to 1.21 per log increase (P-values 0.004 to 0.009). However, adding these miRNAs to established predictors (age, sex, haemoglobin, renal function, and NT-proBNP) did not further augment the c-statistic beyond 0.69 (cohort I) or 0.70 (cohort II).

CONCLUSION

We used a stringent quality assessment for miRNA testing, and were able to replicate the association of miR-1254 and miR-1306-5p with risk of death and HF hospitalization in HF patients of two independent cohorts. However, these two circulating miRNAs failed to improve prognostication over established predictors.

Advances in heart failure: a review of biomarkers, emerging pharmacological therapies, durable mechanical support and telemonitoring

The purpose of this review is to provide an overview of diagnosis, prognosis and management of heart failure (HF) with reduced ejection fraction (HFrEF). Specifically, this review is divided into three sections. The first section will address biomarkers. The discovery of biomarkers has allowed further understanding of the pathophysiology of HF and provides insight into potential therapeutic targets. This review will focus on novel applications of natriuretic peptides (NPs) in clinical trials. Next, emerging biomarkers of HF, such as ST2, galectin-3 and copeptin, will be discussed. The second section aims to highlight HF therapies, including novel drugs and durable devices. The last section will review home haemodynamic monitoring and mobile health. We aim to provide context for the understanding of novel diagnostic and therapeutic advances in HF that are still in phase II or III trials, and have yet to become widely available.

Novel Biomarkers of Heart Failure

Although substantial improvements have been made in majority of cardiac disorders, heart failure (HF) remains a major health problem, with both increasing incidence and prevalence over the past decades. For that reason, the number of potential biomarkers that could contribute to diagnosis and treatment of HF patients is, almost exponentially, increasing over the recent years. The biomarkers that are, at the moment, more or less ready for use in everyday clinical practice, reflect different pathophysiological processes present in HF. In this review, seven groups of biomarkers associated to myocardial stretch (mid-regional proatrial natriuretic peptide, MR-proANP), myocyte injury (high-sensitive troponins, hs-cTn; heart-type fatty acid-binding protein, H-FABP; glutathione transferase P1, GSTP1), matrix remodeling (galectin-3; soluble isoform of suppression of tumorigenicity 2, sST2), inflammation (growth differentiation factor-15, GDF-15), renal dysfunction (neutrophil gelatinase-associated lipocalin, NGAL; kidney injury molecule-1, KIM-1), neurohumoral activation (adrenomedullin, MR-proADM; copeptin), and oxidative stress (ceruloplasmin; myeloperoxidase, MPO; 8-hydroxy-2'-deoxyguanosine, 8-OHdG; thioredoxin 1, Trx1) in HF will be overviewed. It is important to note that clinical value of individual biomarkers within the single time points in both diagnosis and outcome prediction in HF is limited. Hence, the future of biomarker application in HF lies in the multimarker panel strategy, which would include specific combination of biomarkers that reflect different pathophysiological processes underlying HF.

Multi-Biomarker Profiling and Recurrent Hospitalizations in Heart Failure

Background

Despite advances in pharmacologic therapy and devices, patients with heart failure (HF) continue to have significant rehospitalization rates and risk prediction remains challenging. We sought to explore the value of a multi-biomarker panel [including NT-proBNP, high-sensitivity cardiac troponin T (hs-TnT), and ST2] on top of clinical assessment for long-term prediction of recurrent hospitalizations in HF.

Methods and results

NT-proBNP, hs-TnT, and ST2 (suppression of tumorigenicity-2) levels were measured in 891 consecutive ambulatory HF patients. The independent association between the multi-biomarker panel and recurrent hospitalizations was assessed through a multivariable negative binomial regression and expressed as incidence rates ratios. McFadden pseudo-R² and goodness-of-fit measures were also used. The total number of unplanned hospitalizations [all-cause, cardiovascular (CV)-, and HF-related] were selected as the primary endpoints. At a mean follow-up of 4.2 ± 2.1 years, 1623 all-cause hospitalizations in 498 patients (55.9%), 710 CV-related hospitalizations in 331 patients (37.2%), and 444 HF-related hospitalizations in 214 patients (24.1%) were registered. The crude incidence of all-cause, CV-, and HF-related recurrent hospitalizations was significantly higher for patients with the multi-biomarker panel above the cut-point (hs-TnT > 14 ng/L, NT-proBNP > 1000 ng/L, and ST2 > 35 ng/mL) (all P < 0.001). For all-cause, CV-, and HF-related recurrent hospitalizations, the McFadden R², Akaike information criterion, and Bayesian information criterion supported the superiority of incorporating the multi-biomarker panel into a clinical predictive model.

Conclusion

A multi-biomarker approach based on NT-proBNP, hs-TnT, and ST2 better identifies HF patients at risk for recurrent hospitalizations as compared to approaches entailing just one or two of these biomarkers. Elucidation of new biophysiological predictors for recurrent hospitalizations may identify patient profiles for focused intervention.

Soluble ST2 for Prediction of Heart Failure and Cardiovascular Death in an Elderly, Community-Dwelling Population

BACKGROUND

Soluble ST2 (sST2), a marker of myocyte stretch and fibrosis, has prognostic value in many cardiovascular diseases. We hypothesized that sST2 levels are associated with incident heart failure (HF), including subtypes of preserved (HFpEF) and reduced (HFrEF) ejection fraction, and cardiovascular death.

METHODS AND RESULTS

Baseline serum sST2 was measured in 3915 older, community-dwelling subjects from the Cardiovascular Health Study without prevalent HF. sST2 levels were associated with older age, male sex, black race, traditional cardiovascular risk factors, other biomarkers of inflammation, cardiac stretch, myocardial injury, and fibrosis, and abnormal echocardiographic parameters. In longitudinal analysis, greater sST2 was associated with a higher risk of incident HF and cardiovascular death; however, in multivariate models adjusting for other cardiac risk factors and the cardiac-specific biomarker, N-terminal pro-type B natriuretic peptide, these associations were attenuated. In these models, an sST2 level above the US Food and Drug Administration-approved cut-off value (>35 ng/mL) was significantly associated with incident HF (hazard ratio [HR], 1.20; 95% CI, 1.02-1.43) and cardiovascular death (HR, 1.21; 95% CI, 1.02-1.44), and greater sST2 was continuously associated with cardiovascular death (per 1-ln increment: HR, 1.24; 95% CI, 1.02-1.50). sST2 was not associated with the HF subtypes of HFpEF and HFrEF in adjusted analysis. Addition of sST2 to existing risk models of HF and cardiovascular death modestly improved discrimination and reclassification into a higher risk.

CONCLUSIONS

The predictive value of sST2 for HF of all subtypes and cardiovascular death is modest in an elderly population despite strong cross-sectional associations with risk factors and underlying cardiac pathology.

Natural history and therapy of AL cardiac amyloidosis

The natural history of immunoglobulin light chain associated amyloidosis (AL) is determined by the extent of cardiac involvement. Patients with cardiac AL and symptomatic heart failure have a median survival of approximately six months without successful treatment of the underlying plasma cell disorder The outcome in cardiac AL is determined by both the severity of cardiac involvement and the response to treatment. Staging systems using cardiac biomarkers, including NT- proBNP and troponin, have been found to be powerful predictors of prognosis and are used to guide treatment. Arrhythmias are common in cardiac AL and may lead to acute hemodynamic compromise. Sudden cardiac death, often due to pulseless electrical activity, is an important cause of early mortality. Supportive therapy for heart failure is usually limited to diuretics. Beta-blockers, ACE-inhibitors, and angiotensin receptor blockers are poorly tolerated in cardiac AL and should be avoided. Cardiac transplantation is controversial and reserved for highly selected patients with limited extracardiac involvement. The primary target of treatment in cardiac AL is obliteration of the plasma cell clone, using chemotherapy alone or combined with autologous stem cell transplantation. Despite the risk of early mortality, overall survival has improved with advances in disease modifying therapy. Earlier diagnosis and treatment of cardiac AL is crucial to improving survival.

Using ST2 in cardiovascular patients: a review

Biomarkers have emerged as indispensable tools for diagnosis and prognostication in a variety of cardiovascular diseases, and several are now standard of care. New markers are constantly being developed, but few are able to significantly improve upon already established markers. ST2 is a marker of cardiomyocyte stress and fibrosis, which provides incremental value to natriuretic peptides for risk stratification of patients across a wide spectrum of cardiovascular diseases. Based upon the totality of data, measurement of ST2 is now recommended for additive risk stratification in patients with acute or ambulatory heart failure in the 2013 American College of Cardiology Foundation and American Heart Association joint guidelines. Looking forward, ST2 levels may be useful for tailoring medical therapy in those with or at risk for developing heart failure. This paper provides an up-to-date overview of the clinical studies that led to the endorsement of ST2 as a cardiovascular prognostic marker, and provides insight into the application of ST2 now and in the future.

Aging and Heart Rate in Heart Failure: Clinical Implications for Long-term Mortality

OBJECTIVE

To assess the relationship between resting heart rate and long-term all-cause mortality in ambulatory patients with heart failure (HF) relative to age, considering that although heart rate has been strongly associated with mortality in HF, the influence of age on target heart rate is incompletely characterized.

PATIENTS AND METHODS

Consecutive patients in sinus rhythm referred to an ambulatory HF clinic of a university hospital between August 1, 2001, and March 31, 2012, were included. Unadjusted and adjusted Cox regression analyses were performed to assess heart rate as a prognostic marker, both as a continuous variable and after categorization into quintiles. Smooth spline estimates and hazard ratios (HRs) were plotted for 2 age strata (<75 years vs ≥75 years) for each individual heart rate.

RESULTS

A total of 1033 patients were included (766 men [74.2%]; mean age, 65.1±12.6 years). During a mean follow-up of 4.6±3.3 years (median, 3.8 years [25th-75th percentile, 1.9-6.9]), 476 patients (46.1%) died. Mortality was associated with a statistically greater heart rate in the total cohort (HR, 1.18; 95% CI, 1.11-1.26; P<.001). From a clinical viewpoint, this means an 18% increased risk for every 10-beats/min elevation in heart rate. The same characteristics were present in the relationship between heart rate assessed after 6 months and long-term mortality (HR, 1.30; 95% CI, 1.20-1.42; P<.001). Overall, the prognostic importance of heart rate in ambulatory patients with HF was largely influenced by patient age. Remarkably, in the elderly population (≥75 years), heart rate below 68 beats/min conferred an increased risk of death, whereas in younger patients, mortality exhibited a declining slope at even the lowest heart rates.

CONCLUSION

Our research, if applicable to the prospective management of patients with ambulatory HF, suggests that patients aged 75 years or older have the best outcomes with target heart rates of 68 beats/min; however, younger patients may benefit from lower heart rates, even below 55 beats/min.

Soluble suppression of tumorigenicity 2 (sST2), but not galactin-3, adds to prognostication in patients with systemic AL amyloidosis independent of NT-proBNP and troponin T

The use of soluble cardiac biomarkers such as N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin has revolutionized prognostication for patients with AL amyloidosis. Soluble ST2 (sST2) and galectin-3 have also been reported to have prognostic value in other cardiac patient populations. We identified 502 patients with AL amyloidosis, who provided a research sample and consent to review their medical records between 1/1/2006-12/31/2010 within 90 days of their diagnosis. Samples were assayed for sST2 and galectin-3. Within this AL amyloidosis population, overall survival (OS) was 25.5 months (95% CI 18, 35.7 months). Receiver operating curve analyses were done to detect the best cut-points for sST2 and galectin-3 to predict both 1- and 5-year OS. The respective cut points for sST2 were 30 and 29.7 ng/mL, while the median sST2 for the entire population was 31 ng/mL (IQR 19.8, 53.6). The respective cut points for galectin-3 were 11 and 10.4 ng/mL while the median for the entire population was 16.6 ng/mL (IQR 11.5, 24.0). Although on univariate analysis, both sST2 and galectin-3 were prognostic, upon multivariate analysis, only sST2 was independent of troponin, NT-proBNP, serum immunoglobulin free light chain, and blood pressure. Not only did sST2 add to previously reported prognostication systems, but a novel prognostication 5-point system including sST2 was possible. The addition of sST2 - but not galectin-3 - to existing prognostication systems for patients with AL amyloidosis strengthens the ability to predict for death.

Multimarker testing with ST2 in chronic heart failure

Despite important progress in recent decades, mortality remains high for patients with chronic heart failure. Risk stratification may be refined by the use of biomarkers for different pathophysiological processes that established mortality risk factors do not directly reflect. Biomarkers that are currently available can provide information about at least 7 pathobiological processes operative in HF, help to identify the specific processes involved in individual patients, and aid in constructing management plans. However, the additional prognostic information gained by any biomarker over a clinical risk model plus other biomarkers needs to be determined with adequate statistical tools. A major problem in selecting a biomarker profile is the proportional increase in economic burden; thus, the addition of any biomarker to a profile should be justified by adequate discrimination, calibration, reclassification, and likelihood analyses. Three studies that implemented such rigorous analyses have assessed a multimarker panel in chronic heart failure that incorporated the biomarker ST2: the Penn HF Study, the Barcelona Study, and the ProBNP Outpatient Tailored Chronic Heart Failure (PROTECT) biomarker substudy. In all 3 studies, a multimarker panel appeared to provide significant information over conventional risk stratification. The latter 2 reports proposed that ST2 might be superior to natriuretic peptides. The Barcelona Bio-HF calculator (www.bcnbiohfcalculator.cat) is a novel risk calculator that considers clinical variables, treatment, and biomarkers (i.e., N terminal pro-brain natriuretic peptide [NT-proBNP], ST2, and high sensitivity troponin T [hsTnT]). The optimal panel of markers, the change in these markers over time, and how these changes might help guide therapeutic interventions remain to be defined.

Soluble ST2--analytical considerations

Suppression of tumorigenicity 2 (ST2, also known as interleukin [IL]-1 receptor-like-1) is an IL-1 receptor family member with transmembrane (ST2L) and soluble isoforms (sST2). ST2L is a membrane-bound receptor, and IL-33 is the functional ligand for ST2L. sST2, a soluble truncated form of ST2L, is secreted into the circulation and functions as a "decoy" receptor for IL-33, inhibiting IL-33/ST2L signaling. Blood concentrations of sST2 are increased in inflammatory diseases and heart disease and are considered a valuable prognostic marker in both conditions. In multiple clinical trials, sST2 has emerged as a clinically useful prognostic biomarker in patients with cardiac diseases. Interestingly, sST2 even provides prognostic information in low-risk community-based populations. In this review, we will discuss analytical considerations of measuring circulating sST2 including pre-analytical issues, such as in vitro stability of sST2, biological variation of sST2, and postanalytical issues, such as reference ranges and comparisons to diseased cohorts.

Novel Biomarkers in Heart Failure Beyond Natriuretic Peptides - The Case for Soluble ST2

Despite more effective management of heart failure over the past few decades, its burden as a chronic disease has grown and is expected to continue to rise, representing a major health problem for years to come. Having reliable tools for early diagnosis and risk stratification can help managing the condition more efficiently. In this context, the interest for biomarkers has increased considerably in the last years following the useful clinical role of B-type natriuretic peptides. These biomarkers have been extensively studied and have become established diagnostic and prognostic biomarkers in heart failure. Despite their usefulness, limitations still remain a problem in clinical practice and the search for new biomarkers has therefore continued. Amongst the most promising newer biomarkers, soluble ST2 deserves further consideration. The present review will focus on the role of this new biomarker in the context of heart failure.

Renal function largely influences Galectin-3 prognostic value in heart failure

BACKGROUND

Galectin-3 (Gal-3) has been associated with cardiac remodeling and heart failure (HF) prognosis. Renal function is also a well known HF prognostic indicator. The link between renal insufficiency, HF, and Gal-3 is not completely elucidated.

METHODS AND RESULTS

We explored the association between Gal-3 and renal function in a cohort of 876 consecutive ambulatory patients with HF (mean age: 68 years; mean left ventricular ejection fraction [LVEF]: 36%), 52.2% had HF etiology of ischemic heart disease. Circulating Gal-3 was highly correlated with estimated glomerular filtration rate (eGFR), calculated with either the chronic kidney disease-epidemiology (CKD-EPI) equation (r = -0.64) or the CKD-EPI-cystatin-C equation (r = -0.59) and with Cystatin-C levels (r = 0.70), after adjusting for age, sex, New York Heart Association (NYHA) functional class, LVEF, and HF etiology (all p<0.001). Patients were stratified by CKD-EPI-eGFR (ml/min/1.73 m(2)), as follows: ≥ 60 (n = 218), 30 to 59 (n = 434), and <30 (n = 224). In these strata, Gal-3 significantly increased (median [IQR]: 12.3 [10.4-15.6]; 16.1 [13-19.8]; and 24.5 [20-33.8] ng/ml, respectively; trend p < 0.001). This was independent of NYHA functional class (I-II and III-IV) and LVEF (<45% and ≥ 45%). Gal-3 was associated with mortality in univariate analyses, but after adjusting for CKD-EPI-eGFR, the hazard ratios were 1.10 (95% CI: 0.89-1.34, p = 0.39) for all cause death, and 0.90 (95% CI: 0.68-1.21, p = 0.50) for cardiovascular death. Similar results were obtained with eGFRs calculated with the CKD-EPI-cystatin-C equation.

CONCLUSION

Circulating Gal-3 was highly associated with renal function in outpatients with HF. The value of Gal-3 for HF prognosis declined after adjusting for renal function.

Soluble ST2 in heart failure

In addition to routine clinical laboratory tests (including natriuretic peptides and cardiac troponins), other biomarkers are gaining attention for their utility in heart failure (HF) management. Among them, soluble ST2 (sST2) a novel biomarker integrating inflammation, fibrosis, and cardiac stress has been included in the 2013 ACCF/AHA guideline for additive risk stratification of patients with acute and chronic HF. sST2 is an interleukin-1 (IL-1) receptor family member, is secreted into the circulation and functions as a "decoy" receptor for IL-33, inhibiting IL-33/ST2 signaling. Blood concentrations of sST2 are increased in various diseases such as inflammatory diseases and heart diseases and are considered a valuable prognostic marker in both conditions. sST2 lacks disease specificity and, therefore, is not a valuable marker for the diagnosis of HF. In acute and chronic HF, however, sST2 is strongly associated with measures of HF severity and poor outcome. Several studies in patients with HF indicate that serial measurement of sST2 has prognostic value and could have a potential role in future biomarker-directed therapy. In this review, the role of sST2 as a HF biomarker will be discussed, specifically addressing analytical considerations of measuring sST2 as well as the clinical applications of measurement of sST2 for the diagnosis, prognosis and monitoring of acute and chronic HF.

Soluble ST2 serum concentration and renal function in heart failure

BACKGROUND

Soluble ST2 (sST2) provides important prognostic information in patients with heart failure (HF). How sST2 serum concentration is related to renal function is uncertain. We evaluated the association between sST2 and renal function and compared its prognostic value in HF patients with renal insufficiency.

METHODS AND RESULTS

Patients (n = 879; median age 70.4 years; 71.8% men) were divided into 3 subgroups according to estimated glomerular filtration rate (eGFR): ≥60 mL/min/1.73 m(2) (n = 337); 30-59 mL/min/1.73 m(2) (n = 352); and <30 mL/min/1.73 m(2) (n = 190). sST2 (rho = -0.16; P < .001), N-terminal pro-B-type natriuretic peptide (rho = -0.40; P < .001), and high-sensitivity cardiac troponin T (rho = -0.47; P < .001) inversely correlated with eGFR. All-cause mortality was the primary end point. During a median follow-up of 3.46 years, 312 patients (35%) died, 246 of them from the subgroup of 542 patients with eGFR <60 mL/min/1.73 m(2) (45%). Biomarker combination including sST2 showed best discrimination, calibration, and reclassification metrics in renal insufficiency patients (net reclassification improvement 16.6 [95% confidence interval (CI) 8.1-25; P < .001]; integrated discrimination improvement 4.2 [95% CI 2.2-6.2; P < .001]). Improvement in reclassification was higher in these patients than in the total cohort.

CONCLUSIONS

The prognostic value of sST2 was not influenced by renal function. On top of other biomarkers, sST2 improved long-term prediction in patients with renal insufficiency even more than in the total cohort.

2013 update on congenital heart disease, clinical cardiology, heart failure, and heart transplant

This article presents the most relevant developments in 2013 in 3 key areas of cardiology: congenital heart disease, clinical cardiology, and heart failure and transplant. Within the area of congenital heart disease, we reviewed contributions related to sudden death in adult congenital heart disease, the importance of specific echocardiographic parameters in assessing the systemic right ventricle, problems in patients with repaired tetralogy of Fallot and indication for pulmonary valve replacement, and confirmation of the role of specific factors in the selection of candidates for Fontan surgery. The most recent publications in clinical cardiology include a study by a European working group on correct diagnostic work-up in cardiomyopathies, studies on the cost-effectiveness of percutaneous aortic valve implantation, a consensus document on the management of type B aortic dissection, and guidelines on aortic valve and ascending aortic disease. The most noteworthy developments in heart failure and transplantation include new American guidelines on heart failure, therapeutic advances in acute heart failure (serelaxin), the management of comorbidities such as iron deficiency, risk assessment using new biomarkers, and advances in ventricular assist devices.

Development of a novel heart failure risk tool: the barcelona bio-heart failure risk calculator (BCN bio-HF calculator)

BACKGROUND

A combination of clinical and routine laboratory data with biomarkers reflecting different pathophysiological pathways may help to refine risk stratification in heart failure (HF). A novel calculator (BCN Bio-HF calculator) incorporating N-terminal pro B-type natriuretic peptide (NT-proBNP, a marker of myocardial stretch), high-sensitivity cardiac troponin T (hs-cTnT, a marker of myocyte injury), and high-sensitivity soluble ST2 (ST2), (reflective of myocardial fibrosis and remodeling) was developed.

METHODS

Model performance was evaluated using discrimination, calibration, and reclassification tools for 1-, 2-, and 3-year mortality. Ten-fold cross-validation with 1000 bootstrapping was used.

RESULTS

The BCN Bio-HF calculator was derived from 864 consecutive outpatients (72% men) with mean age 68.2 ± 12 years (73%/27% New York Heart Association (NYHA) class I-II/III-IV, LVEF 36%, ischemic etiology 52.2%) and followed for a median of 3.4 years (305 deaths). After an initial evaluation of 23 variables, eight independent models were developed. The variables included in these models were age, sex, NYHA functional class, left ventricular ejection fraction, serum sodium, estimated glomerular filtration rate, hemoglobin, loop diuretic dose, β-blocker, Angiotensin converting enzyme inhibitor/Angiotensin-2 receptor blocker and statin treatments, and hs-cTnT, ST2, and NT-proBNP levels. The calculator may run with the availability of none, one, two, or the three biomarkers. The calculated risk of death was significantly changed by additive biomarker data. The average C-statistic in cross-validation analysis was 0.79.

CONCLUSIONS

A new HF risk-calculator that incorporates available biomarkers reflecting different pathophysiological pathways better allowed individual prediction of death at 1, 2, and 3 years.

Head-to-head comparison of 2 myocardial fibrosis biomarkers for long-term heart failure risk stratification: ST2 versus galectin-3

OBJECTIVES

ST2 and galectin-3 (Gal-3) were compared head-to-head for long-term risk stratification in an ambulatory heart failure (HF) population on top of other risk factors including N-terminal pro-B-type natriuretic peptide.

BACKGROUND

ST2 and Gal-3 are promising biomarkers of myocardial fibrosis and remodeling in HF.

METHODS

This cohort study included 876 patients (median age: 70 years, median left ventricular ejection fraction: 34%). The 2 biomarkers were evaluated relative to conventional assessment (11 risk factors) plus N-terminal pro-B-type natriuretic peptide in terms of discrimination, calibration, and reclassification analysis. Endpoints were 5-year all-cause and cardiovascular mortality, and the combined all-cause death/HF hospitalization.

RESULTS

During a median follow-up of 4.2 years (5.9 for alive patients), 392 patients died. In bivariate analysis, Gal-3 and ST2 were independent variables for all endpoints. In multivariate analysis, only ST2 remained independently associated with cardiovascular mortality (hazard ratio: 1.27, 95% confidence interval [CI]: 1.05 to 1.53, p = 0.014). Incorporation of ST2 into a full-adjusted model for all-cause mortality (including clinical variables and N-terminal pro-B-type natriuretic peptide) improved discrimination (C-statistic: 0.77, p = 0.004) and calibration, and reclassified significantly better (integrated discrimination improvement: 1.5, 95% CI: 0.5 to 2.5, p = 0.003; net reclassification index: 9.4, 95% CI: 4.8 to 14.1, p < 0.001). Incorporation of Gal-3 showed no significant increase in discrimination or reclassification and worse calibration metrics. On direct model comparison, ST2 was superior to Gal-3.

CONCLUSIONS

Head-to-head comparison of fibrosis biomarkers ST2 and Gal-3 in chronic HF revealed superiority of ST2 over Gal-3 in risk stratification. The incremental predictive contribution of Gal-3 to existing clinical risk factors was trivial.