Increased Plasma Concentrations of Soluble ST2 are Predictive for 1-Year Mortality in Patients with Acute Destabilized Heart Failure

Association of suPAR, ST2, and galectin-3 with eGFR decline and mortality in patients with advanced heart failure with reduced ejection fraction

Patients with heart failure with reduced ejection fraction (HFrEF) are at risk for chronic kidney disease (CKD). Elevated levels of circulating biomarkers soluble urokinase plasminogen activator receptor (suPAR), galectin-3, soluble suppression of tumorigenicity 2 (ST2), and N-terminal prohormone B-type natriuretic peptide (NT-proBNP) are associated with CKD progression and mortality. The predictive value of these biomarkers in a population with HFrEF and kidney disease is relatively unknown. We sought to determine whether these biomarkers were associated with longitudinal trajectory of estimated glomerular filtration rate (eGFR) in HFrEF and assess their association with mortality using a joint model to account for competing risks of ventricular assist device (VAD) implantation and heart transplantation. We included participants from the Registry Evaluation of Vital Information for Ventricular Assist Devices in Ambulatory Life with repeated eGFR measures over 2 years. Of 309 participants, mean age was 59 years, median eGFR 60 ml/min/1.73 m2, 45 participants died, 33 received VAD, and 25 received orthotopic heart transplantation. Higher baseline serum standardized suPAR (β coefficient = -0.36 √(ml/min/1.73 m2), 95% confidence interval (-0.48 to -0.24), p < 0.001), standardized galectin-3 (-0.14 √(ml/min/1.73 m2) (-0.27 to -0.02), p = 0.02), and log NT-proBNP (-0.23 √(ml/min/1.73 m2) (-0.31 to -0.15), p < 0.001) were associated with eGFR decline. ST2 and log NT-proBNP were associated with mortality. Higher baseline suPAR, galectin-3, and NT-proBNP are associated with eGFR decline in patients with HFrEF. Only ST2 and NT-proBNP are associated with greater mortality after controlling for other factors including change in eGFR. These biomarkers may provide prognostic value for kidney disease progression in HFrEF and inform candidacy for advanced heart failure therapies.

Association of point-of-care testing for sST2 with clinical outcomes in patients hospitalized with heart failure

AIMS

This study aimed to investigate the association of soluble suppression of tumorigenicity-2 (sST2) measured by point-of-care testing assay with clinical outcomes in patients hospitalized with heart failure after adjusting for other predictors including N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT).

METHODS

A total of 1726 consecutive patients hospitalized with heart failure from July 2015 to December 2021 were enrolled. Baseline serum sST2 concentrations were measured by immunofluorescence assay. Primary endpoint event was the composite of all-cause death, heart transplantation, or left ventricular assist device.

RESULTS

During the median follow-up duration of 682 days, 434 patients (25.1%) suffered from primary endpoint events. Baseline sST2 remained an independent predictor of the primary endpoint event in patients hospitalized with heart failure after adjusting for other predictors including NT-proBNP and hs-cTnT [per log (unit) increase, adjusted hazard ratio (HR) (95% confidence interval) (CI): 1.20 (1.09, 1.32), P < 0.001]. And baseline sST2 had a better prognostic value for patients with chronic decompensated heart failure [per log (unit) increase, adjusted HR (95% CI): 1.19 (1.07, 1.31)] than for those with acute new onset heart failure [per log (unit) increase, adjusted HR (95% CI): 1.28 (0.94, 1.75), P value for interaction <0.001], as well as a better prognostic value for patients with New York Heart Association (NYHA) functional class I-II [per log (unit) increase, adjusted HR (95% CI): 1.67 (1.11, 2.52)] than for those with NYHA functional class III-IV [per log (unit) increase, adjusted HR (95% CI): 1.18 (1.07, 1.31), P value for interaction <0.001]. Baseline sST2 was also a good predictor of the primary endpoint event in patients hospitalized with heart failure at 1 month, 3 months, 1 year and 2 years (area under the curve: 0.789, 0.775, 0.736 and 0.733, respectively), and the best cut-off values were 27.2 ng/ml, 27.1 ng/ml, 27.1 ng/ml and 25.1 ng/ml, respectively. Furthermore, baseline sST2 could provide additional prognostic value when added to baseline NT-proBNP and hs-cTnT (all P values <0.05). According to the category of elevated biomarkers (including NT-proBNP, hs-cTnT, and sST2), patients with three elevated biomarkers had a higher risk of the primary endpoint event compared with those with one or two elevated biomarkers (all P values <0.05).

CONCLUSIONS

Baseline sST2 remained an independent predictor of adverse events after adjusting for other predictors including NT-proBNP and hs-cTnT, particularly in patients with chronic decompensated heart failure and NYHA functional class I-II. And in the basis of baseline NT-proBNP and hs-cTnT, adding baseline sST2 could provide additional prognostic value for patients hospitalized with heart failure.

Association of soluble ST2 Level with 6-month Mortality and/or Recurrent Cardiovascular-Related Hospitalization in Pulmonary Embolism

BACKGROUND

The association of soluble suppression of tumorigenesis-2 (sST2) levels with prognosis in pulmonary embolism (PE) is unknown.

OBJECTIVE

This study aimed to investigate the relationship between sST2 levels in patients with acute PE and 6-month mortality and recurrent hospitalizations.

METHODS

This prospective study included 100 patients with acute PE. Patients were classified into two groups according to 6-month mortality and the presence of recurrent Cardiovascular-Related hospitalizations. Two groups were compared. A p-value of 0.05 was considered statistically significant.

RESULTS

Soluble ST2 levels were significantly higher in the group with mortality and recurrent hospitalizations. (138.6 ng/mL (56.7-236.8) vs. 38 ng/mL (26.3-75.4); p<0.001) The best cut-off threshold for sST2 levels in the prediction of a composite outcome of 6-month mortality and/or recurrent Cardiovascular-Related hospitalization was found to be >89.9 with a specificity of 90.6% and a sensitivity of 65.2%, according to the receiver operating characteristic curve (area under the curve = 0.798; 95% CI, 0.705-0.891; p <0.0001). After adjusting for confounding factors that were either statistically significant in the univariate analysis or for the variables correlated with the sST2 levels, sST2 level (OR = 1.019, 95% CI: 1.009-1.028, p 0.001) and C-reactive protein (CRP ) (OR = 1.010, 95% CI: 1.001-1.021, p = 0.046) continued to be significant predictors of 6-month mortality and/or recurrent Cardiovascular-Related hospitalization in the multiple logistic regression model via backward stepwise method.

CONCLUSION

Soluble ST2 level seems to be a biomarker to predict 6-month mortality and/or recurrent Cardiovascular-Related hospitalization in patients with acute PE.

Assessment of Troponin I Levels as a Predictor of Mortality in Acute Decompensated Heart Failure

BACKGROUND

Acute decompensated heart failure (ADHF) is a highly prevalent diagnosis in the emergency department and is associated with high morbidity and mortality. As mortality remains high even in patients discharged from the emergency, it becomes mandatory to identify markers predictive of mortality in order to guide the disposition of such patients. No literature is available on the prognostic significance of Troponin I in ADHF patients in an emergency setting from an Indian standpoint.

OBJECTIVES

This study was aimed at identifying the ability of Troponin I levels at presentation to predict one-month mortality in patients with ADHF.

METHODS

The study was conducted in the emergency department of a tertiary healthcare center in north India. Serum cardiac Troponin I (cTnI) levels at presentation were assayed in 101 patients and a one-month follow-up was done.

RESULTS

cTnI levels were > 0.02 ng/mL in 51 patients (50.5%). ROC analysis showed an accuracy of 63% in predicting mortality (p < 0.05). Univariate and multivariate analysis showed an OR of 2.58 and 2.74, respectively (p - 0.037 and 0.047, respectively), suggesting cTnI to be a significant predictor of mortality in ADHF. N-terminal proBNP (NT-proBNP) (OR - 2.09; p - 0.229) and left ventricular ejection fraction (OR - 2.01; p - 0.157) were not found to be significant predictors of mortality on regression analysis.

CONCLUSION

cTnI levels at presentation are a significant predictor of short-term mortality in ADHF and can be used in an emergency setting to guide treatment, disposition, and follow-up plans of these patients.

The ST2/IL-33 Pathway in Adult and Paediatric Heart Disease and Transplantation

ST2 is a member of interleukin 1 receptor family with soluble sST2 and transmembrane ST2L isoforms. The ligand of ST2 is IL-33, which determines the activation of numerous intracytoplasmic mediators following the binding with ST2L and IL-1RAcP, leading to nuclear signal and cardiovascular effect. Differently, sST2 is released in the blood and works as a decoy receptor, binding IL-33 and blocking IL-33/ST2L interaction. sST2 is mainly involved in maintaining homeostasis and/or alterations of different tissues, as counterbalance/activation of IL-33/ST2L axis is typically involved in the development of fibrosis, tissue damage, inflammation and remodeling. sST2 has been described in different clinical reports as a fundamental prognostic marker in patients with cardiovascular disease, as well as marker for the treatment monitoring of patients with heart failure; however, further studies are needed to better elucidate its role. In this review we reported the current knowledge about its role in coronary artery disease, heart failure, heart transplantation, heart valve disease, pulmonary arterial hypertension, and cardiovascular interventions.

Elevated Soluble Suppressor of Tumorigenicity 2 Predict Hospital Admissions Due to Major Adverse Cardiovascular Events (MACE)

The role of soluble suppression of tumorigenicity (sST2) as a biomarker in predicting clinical outcomes in patients with cardiovascular diseases (CVD) has not been fully elucidated. In this study, we sought to determine the relationship between sST2 levels and any unplanned hospital readmissions due to a major adverse cardiovascular event (MACE) within 1 year of first admission. Patients (n = 250) admitted to the cardiology unit at John Hunter Hospital were recruited. Occurrences of MACE, defined as the composite of total death, myocardial infarction (MI), stroke, readmissions for heart failure (HF), or coronary revascularization, were recorded after 30, 90, 180, and 365 days of first admission. On univariate analysis, patients with atrial fibrillation (AF) and HF had significantly higher sST2 levels vs. those who did not. Increasing levels of sST2 by quartiles were significantly associated with AF, HF, older age, low hemoglobin, low eGFR, and high CRP levels. On multivariate analysis: high sST2 levels and diabetes remained as risk predictors of any MACE occurrence; an sST2 level in the highest quartile (Q4: >28.4 ng/mL) was independently associated with older age, use of beta-blockers, and number of MACE events within a 1 year period. In this patient cohort, elevated sST2 levels are associated with unplanned hospital admission due to MACE within 1 year, independent of the nature of the index cardiovascular admission.

Pathophysiology-Based Management of Acute Heart Failure

Even though acute heart failure (AHF) is one of the most common admission diagnoses globally, its pathogenesis is poorly understood, and there are few effective treatments available. Despite an heterogenous onset, congestion is the leading contributor to hospitalization, making it a crucial therapeutic target. Complete decongestion, nevertheless, may be hard to achieve, especially in patients with reduced end organ perfusion. In order to promote a personalised pathophysiological-based therapy for patients with AHF, we will address in this review the pathophysiological principles that underlie the clinical symptoms of AHF as well as examine how to assess them in clinical practice, suggesting that gaining a deeper understanding of pathophysiology might result in significant improvements in HF therapy.

Elevated Plasma Soluble ST2 Levels are Associated With Neuronal Injury and Neurocognitive Impairment in Children With Cerebral Malaria

Background

Murine experimental cerebral malaria studies suggest both protective and deleterious central nervous system effects from alterations in the interleukin-33 (IL-33)/ST2 pathway.

Methods

We assessed whether soluble ST2 (sST2) was associated with neuronal injury or cognitive impairment in a cohort of Ugandan children with cerebral malaria (CM, n=224) or severe malarial anemia (SMA, n=193).

Results

Plasma concentrations of sST2 were higher in children with CM than in children with SMA or in asymptomatic community children. Cerebrospinal fluid (CSF) sST2 levels were elevated in children with CM compared with North American children. Elevated plasma and CSF ST2 levels in children with CM correlated with increased endothelial activation and increased plasma and CSF levels of tau, a marker of neuronal injury. In children with CM who were ≥5 years of age at the time of their malaria episode, but not in children <5 years of age, elevated risk factor-adjusted plasma levels of sST2 were associated with worse scores for overall cognitive ability and attention over a 2-year follow-up.

Conclusions

The study findings suggest that sST2 may contribute to neuronal injury and long-term neurocognitive impairment in older children with CM.

Soluble suppression of tumorigenesis-2 (sST2) is a strong predictor of all-cause, cardiovascular and infection-related mortality risk in hemodialysis patients with diabetes mellitus

Background

Soluble suppression of tumorigenesis-2 (sST2) is a strong prognostic biomarker of cardiovascular (CV) disease. End-stage kidney disease (ESKD) patients are at high risk of CV events and infections. Herein we investigated the utility of sST2 to predict all-cause and cause-specific mortality in haemodialysis (HD) patients with diabetes mellitus.

Methods

sST2 concentrations were measured in plasma samples of 1196 participants of the German Diabetes and Dialysis (4D) study who had type 2 diabetes mellitus and received maintenance HD for ESKD. Hazard ratios (HRs) for prespecified, adjudicated endpoints were determined according to sST2 levels at baseline by multivariate Cox proportional hazards analysis.

Results

Participants (mean age 66 years, 54% male) had a median sST2 concentration of 25 ng/mL and were followed up for 4 years. After adjustment for possible confounders, participants with sST2 concentrations in the highest (>32.6 ng/mL) compared with the lowest (<20.1 ng/mL) quartile exhibited a 2-fold higher all-cause mortality risk {[HR 2.06 95% confidence interval (CI) 1.61–2.61]; P < .001}. High sST concentrations (fourth versus first quartile) were strongly associated with the risk of cardiac death [HR 2.29 (95% CI 1.55–3.39); P < .001]. Analysis of individual components of cardiac causes of death showed an increased risk of sudden death [HR 2.24 (95% CI 1.33–3.77); P < .001], death due to myocardial infarction [HR 2.12 (95% CI 0.9–5.0); P = .087] and heart failure [HR 3.34 (95% CI 1.15–9.75); P = .027] in participants with sST2 levels in the highest compared with the lowest quartile. Likewise, participants with the highest sST2 levels had an increased risk of fatal stroke [HR 1.92 (95% CI 1.17–3.14); P = .009] and fatal infections [HR 2.01 (95% CI 1.2–3.37); P = .008]. In contrast to fatal CV events, sST2 was not associated with the risk of non-fatal myocardial infarction [HR 0.68 (95% CI 0.41–1.12); P = .132] or non-fatal stroke [HR 1.28 (95% CI 0.64–2.53); P = .485].

Conclusions

In HD patients with diabetes mellitus, high concentrations of sST2 were strongly and independently associated with an increased risk of all-cause mortality, CV mortality and death due to infection but not non-fatal CV events.

Role of biomarkers in the heart failure clinic

Heart failure (HF) is a common cardiovascular disease that has a complex pathophysiology. Because it is the final stage of many cardiovascular diseases, proper diagnosis and treatment are crucial for prolonging patients’ survival and improving their well-being. Several biomarkers have been identified in HF, and their roles in diagnosis and prognostication have been widely investigated. Among them, natriuretic peptides are key for diagnosing HF, predicting its prognosis, and monitoring the effectiveness of HF treatment. Moreover, natriuretic peptides can also be used to treat HF. In addition to natriuretic peptides, several other biomarkers were included in the most recent HF management guidelines. Thus, we reviewed the role of the biomarkers included in these guidelines and discussed future perspectives.

Soluble suppression of tumorigenicity 2 (sST2) for predicting disease severity or mortality outcomes in cardiovascular diseases: A systematic review and meta-analysis

OBJECTIVES

Soluble suppression of tumorigenicity 2 (sST2) is a member of the interleukin-1 receptor family. It is raised in various cardiovascular diseases, but its value in predicting disease severity or mortality outcomes has been controversial. Therefore, we conducted a systematic review and meta-analysis to determine whether sST2 levels differed between survivors and non-survivors of patients with cardiovascular diseases, and whether elevated sST2 levels correlated with adverse outcomes.

METHODS

PubMed and Embase were searched until 23rd June 2021 for studies that evaluated the relationship between sST2 levels and cardiovascular disease severity or mortality.

RESULTS

A total of 707 entries were retrieved from both databases, of which 14 studies were included in the final meta-analysis. In acute heart failure, sST2 levels did not differ between survivors and non-survivors (mean difference [MD]: 24.2 ± 13.0 ng/ml; P = 0.06; I 2: 95%). Elevated sST2 levels tend to be associated with increased mortality risk (hazard ratio [HR]: 1.12, 95 %CI: 0.99-1.27, P = 0.07; I 2: 88%). In chronic heart failure, sST2 levels were higher in non-survivors than in survivors (MD: 0.19 ± 0.04 ng/ml; P = 0.001; I 2: 0%) and elevated levels were associated with increased mortality risk (HR: 1.64, 95% CI: 1.27-2.12, P < 0.001; I 2: 82%). sST2 levels were significantly higher in severe disease compared to less severe disease (MD: 1.56 ± 0.46 ng/ml; P = 0.001; I 2: 98%). Finally, in stable coronary artery disease, sST2 levels were higher in non-survivors than survivors (MD: 3.0 ± 1.1 ng/ml; P = 0.005; I 2: 80%) and elevated levels were significantly associated with increased mortality risk (HR: 1.32, 95% CI: 1.04-1.68, P < 0.05; I 2: 57%).

CONCLUSIONS

sST2 significantly predicts disease severity and mortality in cardiovascular disease and is a good predictor of mortality in patients with stable coronary artery disease and chronic heart failure.

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

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

Randomised controlled trial into the role of ramipril in fibrosis reduction in rheumatic heart disease: the RamiRHeD trial protocol

INTRODUCTION

Rheumatic heart disease (RHD) is a major burden in developing countries and accounts for 80% of all people living with the disease, where it causes most cardiovascular morbidity and mortality in children and young adults. Chronic inflammation and fibrosis of heart valve tissue due to chronic inflammation in RHD will cause calcification and thickening of the impacted heart valves, especially the mitral valve. This fibrogenesis is enhanced by the production of angiotensin II by increased transforming growth factor β expression and later by the binding of interleukin-33, which is known to have antihypertrophic and antifibrotic effects, to soluble sST2. sST2 binding to this non-natural ligand worsens fibrosis. Therefore, we hypothesise that ACE inhibitors (ACEIs) would improve rheumatic mitral valve stenosis.

METHODS AND ANALYSIS

This is a single-centre, double-blind, placebo-controlled, randomised clinical trial with a pre-post test design. Patients with rheumatic mitral stenosis and valve dysfunction will be planned for cardiac valve replacement operation and will be given ramipril 5 mg or placebo for a minimum of 12 weeks before the surgery. The expression of ST2 in the mitral valve is considered to be representative of cardiac fibrosis. Mitral valve tissue will be stained by immunohistochemistry to ST2. Plasma ST2 will be measured by ELISA. This study is conducted in the Department of Cardiology and Vascular Medicine, Universitas Indonesia, National Cardiac Center Harapan Kita Hospital, Jakarta, Indonesia, starting on 27 June 2019.

ETHICS AND DISSEMINATION

The performance and dissemination of this study were approved by the ethics committee of National Cardiovascular Center Harapan Kita with ethical code LB.02.01/VII/286/KEP.009/2018.

TRIAL REGISTRATION NUMBER

NCT03991910.

Predictive values of sST2 and IL-33 for heart failure in patients with acute myocardial infarction

Timely prediction of the risk of heart failure in acute myocardial infarction patients is critical for better prognosis. This article aims to evaluate the predictive value of serum soluble growth stimulation expressed gene 2 (sST2) and interleukin-33 in patients with acute myocardial infarction complicated by heart failure. A total of 42 healthy controls and 144 acute myocardial infarction patients were recruited in the study. According to Killip cardiac function classification as the basis for concurrent heart failure, they were distributed into non-heart failure group (n = 76) and heart failure group (n = 68). ELISA was utilized to determine the serum sST2 and interleukin-33 levels, and the diagnostic efficiency was evaluated by receiver operating characteristics curve. sST2 and interleukin-33 levels in patients with acute myocardial infarction were significantly increased when compared with normal healthy controls, and were further enhanced in the heart failure group. With the increased Killip cardiac function classification, interleukin-33 and sST2 levels were gradually elevated. Multivariate analysis indicated that interleukin-33 and sST2 could be used as independent predictors for heart failure combined with acute myocardial infarction.

Predictive Value of Sirtuins in Acute Myocardial Infarction - Bridging the Bench to the Clinical Practice

Acute myocardial infarction (AMI) is a non-transmissible condition with high prevalence, morbidity, and mortality. Different strategies for the management of AMI are employed worldwide, but its early diagnosis remains a major challenge. Many molecules have been proposed in recent years as predictive agents in the early detection of AMI, including troponin (C, T, and I), creatine kinase MB isoenzyme, myoglobin, heart-type fatty acid-binding protein, and a family of histone deacetylases with enzymatic activities named sirtuins. Sirtuins may be used as predictive or complementary treatment strategies and the results of recent preclinical studies are promising. However, human clinical trials and data are scarce, and many issues have been raised regarding the predictive values of sirtuins. The present review summarizes research on the predictive value of sirtuins in AMI. We also briefly summarize relevant clinical trials and discuss future perspectives and possible clinical applications.

Why Do We Not Assess Sympathetic Nervous System Activity in Heart Failure Management: Might GRK2 Serve as a New Biomarker?

Heart failure (HF) represents the end-stage condition of several structural and functional cardiovascular diseases, characterized by reduced myocardial pump function and increased pressure load. The dysregulation of neurohormonal systems, especially the hyperactivity of the cardiac adrenergic nervous system (ANS), constitutes a hallmark of HF and exerts a pivotal role in its progression. Indeed, it negatively affects patients’ prognosis, being associated with high morbidity and mortality rates, with a tremendous burden on global healthcare systems. To date, all the techniques proposed to assess the cardiac sympathetic nervous system are burdened by intrinsic limits that hinder their implementation in clinical practice. Several biomarkers related to ANS activity, which may potentially support the clinical management of such a complex syndrome, are slow to be implemented in the routine practice for several limitations due to their assessment and clinical impact. Lymphocyte G-protein-coupled Receptor Kinase 2 (GRK2) levels reflect myocardial β-adrenergic receptor function in HF and have been shown to add independent prognostic information related to ANS overdrive. In the present manuscript, we provide an overview of the techniques currently available to evaluate cardiac ANS in HF and future perspectives in this field of relevant scientific and clinical interest.

Development of a Novel Homogeneous Nanoparticle-Based Assay for Rapid and High-Throughput Quantitation of the sST2 Protein in Human Serum

Purpose

The suppression of tumorigenicity 2 (ST2) protein is a member of the interleukin-1 receptor family with the transmembrane (ST2L) and soluble (sST2) subtypes and plays an important role in several diseases. Therefore, the present study aimed to establish and validate a novel amplified luminescent proximity homogeneous immunoassay (AlphaLISA) for the detection of sST2 in human serum.

Materials and Methods

Based on a sandwich-type immunoassay format, sST2 was captured using two different anti-sST2 antibodies. One of the antibodies was biotinylated while the other one was coated with AlphaLISA chemibeads. Thereafter, multiple tests were conducted to optimize the working conditions and validate analytical performance.

Results

The optimum concentration of the biotinylated antibodies was 1 μg/mL while the optimal dilution ratio for the anti-sST2 antibodies and conjugated chemibeads was 1:500. In addition, the optimal antigen-antibody reaction time was 15 minutes (min). Notably, the developed method showed a short turnaround time of about 25 min. Moreover, the assay exhibited high sensitivity with a limit of detection (LOD) of 0.176 ng/mL and a limit of quantification (LOQ) of 0.8 ng/mL. Furthermore, the intra-assay precision and inter-assay precision values were 5.29–7.10% and 9.41%–13.66%, respectively. It is also noteworthy that the test results deviated by less than ±10% when samples had ≤10.0 ng/mL of triglycerides, ≤0.5 mmol/L of bilirubin, ≤5.0 g/L of triglyceride, and ≤250 μg/L of biotin. Additionally, the developed assay was almost consistent with the commercially available PresageTM ST2 assay kit, with a Spearman correlation coefficient of 0.916 and an R² of 0.963 as well as a slope of 0.957 from linear regression analysis.

Conclusion

The present study showed that the sandwich AlphaLISA is a rapid, high-throughput, and reliable test for studying the levels of sST2 in a variety of diseases.

sST2 adds to the prognostic value of Gal-3 and BNP in chronic heart failure

Background: The soluble form of the IL-33 receptor (sST2) and Galectin-3 (Gal-3) are fibrosis biomarkers with prognostic value in heart failure (HF). We investigated the prognostic capacity of sST2 when combined with Gal-3, and determined if the prognostic utility of sST2 is affected by mineralocorticoid receptor antagonist (MRA) therapy.Methods: sST-2 and Gal-3 were measured in 101 stable chronic HF (CHF) patients receiving MRA therapy and compared to 97 BNP and cardiovascular risk factor matched patients not treated with MRA. sST2 and Gal-3 levels were measured to determine the relationship with all-cause mortality at 6-year follow-up.Results: ROC curve cut-off points were defined as sST2 = 36.3 ng/mL, Gal-3 = 17.8 ng/mL, and BNP = 500 pg/mL, and had 6-year mortality hazard ratios (HR) of 7.3, 6.6 and 5.4, respectively. The combination of an elevated sST2 and Gal-3 had a HR = 4.4 [95% CI 1.9-8.9]. Combining sST2 and Gal-3 to a clinical model relevant for CHF prognosis allowed a significant reclassification of 1-year adverse outcome risk, even when BNP was included. Finally, prognostic prediction by sST2 was unaffected by MRA treatment.Conclusion: Simultaneous sST2 and Gal-3 elevation is associated with poorer prognosis compared to either alone, regardless of BNP levels, and the prognostic capacity of sST2 is independent of MRA therapy.

Galectin-3, GDF-15, and sST2 for the assessment of disease severity and therapy response in patients suffering from inoperable chronic thromboembolic pulmonary hypertension

PURPOSE

This study examined sST2, GDF-15, and galectin-3 as indicators of disease severity and therapy response in chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

This study included 57 inoperable CTEPH patients who underwent balloon pulmonary angioplasty and 25 controls without cardiovascular disease. Biomarker levels were examined in relation to advanced hemodynamic impairment [tertile with worst right atrial pressure (RAP) and cardiac index], hemodynamic therapy response [normalized hemodynamics (meanPAP ≤25 mmHg, PVR ≤3 WU and RAP ≤6 mmHg) or a reduction of meanPAP ≥25%; PVR ≥ 35%, RAP ≥25%].

RESULTS

GDF-15 [820 (556-1315) pg/ml vs. 370 (314-516) pg/ml; p < 0.001] and sST2 [53.7 (45.3-74.1) ng/ml vs. 48.7 (35.5-57.0) ng/ml; p = 0.02] were higher in CTEPH patients than in controls. At baseline, a GDF-15 level ≥1443 pg/ml (AUC 0.88; OR 31.4) and a sST2 level ≥65 ng/ml (AUC 0.80; OR 10.9) were associated with advanced hemodynamic impairment. At follow-up GDF-15 ≤ 958 pg/ml (AUC = 0.74, OR 18) identified patients with optimal hemodynamic therapy response and ≤760 pg/ml (AUC = 0.79, OR 14).

CONCLUSION

GDF-15 and sST2 levels are higher in CTEPH and identified patients with advanced hemodynamic impairment. Further, decreased GDF-15 levels at follow-up were associated with hemodynamic therapy response. The diagnostic strength was not superior to NT-proBNP.

Role of biomarkers of cardiac remodeling, myofibrosis, and inflammation in assessment of disease severity in euvolemic patients with chronic stable heart failure

OBJECTIVE

This study aimed to determine the importance of biomarkers of chronic heart failure (CHF) for assessing disease severity in euvolemic stable patients.

PATIENTS AND METHODS

N-terminal pro-B-type natriuretic peptide (NT-proBNP), growth differentiation factor (GDF)-15, galectin-3, cystatin-C, soluble suppression of tumorigenicity 2 (sST2), tissue type inhibitor of matrix metalloproteinase (TIMP)-1, and ceruloplasmin levels were measured in euvolemic patients with stable CHF. Severity of CHF was defined by echocardiographic and biochemical parameters.

RESULTS

In 160 patients (123 men and 37 women, mean age: 65.8±12.2 years), we found strong associations between NT-proBNP and bilirubin levels (r = 0.434) and the estimated glomerular filtration rate (r = -0.321). GDF-15 and cystatin-C levels were significantly correlated with parameters of kidney function. In multivariable regression analysis, NT-proBNP levels were associated with the left ventricular ejection fraction and left ventricular end-systolic volume (coefficient of determination R2 = 0.777). Additionally, GDF-15 levels were correlated with urea levels (R2 = 0.742), and cystatin C levels were correlated with urea and bilirubin levels (R2 = 0.732).

CONCLUSION

Besides NT-proBNP, GDF-15 and cystatin C are promising biomarkers for establishing the severity of disease in euvolemic patients with stable CHF.

Multimarker approach including CRP, sST2 and GDF-15 for prognostic stratification in stable heart failure

Aims

Inflammation and cardiac remodelling are common and synergistic pathways in heart failure (HF). Emerging biomarkers such as soluble suppression of tumorigenicity 2 (sST2) and growth differentiation factor‐15 (GDF‐15), which are linked to inflammation and fibrosis process, have been proposed as prognosis factors. However, their potential additive values remain poorly investigated.

Methods and results

Here, we aimed at evaluating inflammatory and remodelling biomarkers to predict both short‐term and long‐term mortality in a population with chronic HF in comparison with other classical clinical or biological markers (i.e. N terminal pro brain natriuretic peptide, hs‐cTnT, C‐reactive protein) alone or using meta‐analysis global group in chronic HF risk score in a cohort of 182 patients followed during 80 months (interquartile range: 12.3–90.0). Proportional hazard assumption does not hold for sST2 and C‐reactive protein, and follow‐up was split into short term (less than 1 year), midterm (between 1 and 5 years), and long term (after 5 years). In univariate analysis, C‐reactive protein and sST2 were predictive of short‐term mortality but not of middle term and long term whereas GDF‐15 was predictive of short and mid‐term but not of long‐term mortality. In a multivariate model after adjustment for meta‐analysis global group in chronic HF score including the three markers, only sST2 was predictive of short‐term mortality (P = 0.0225), and only GDF‐15 was predictive of middle term mortality (P = 0.0375). None of the markers was predictive of long‐term mortality.

Conclusions

Our results demonstrate that both sST2 and GDF‐15 significantly improve the prognosis evaluation of HF patients and suggest that the value of GDF‐15 is more sustained overtime and could predict middle term events.

Biomarkers in heart failure: the past, current and future

Despite the enhanced knowledge of the pathophysiology of heart failure (HF), it still remains a serious syndrome with substantial morbidity, mortality, and frequent hospitalizations. These are due to the current improvements in other cardiovascular diseases (like myocardial infarction), the aging population, and growing prevalence of comorbidities. Biomarker-guided management has brought a new dimension in prognostication, diagnosis, and therapy options. Following the recommendation of natriuretic peptides (B-type natriuretic peptide and N-terminal-proBNP), many other biomarkers have been thoroughly studied to reflect different pathophysiological processes (such as fibrosis, inflammation, myocardial injury, and remodeling) in HF and some of them (like cardiac troponins, soluble suppression of tumorigenesis-2, and galectin 3) have subsequently been recommended to aid in the diagnosis and prognostication in HF. Consequently, multi-marker approach has also been approved owing to the varied nature of HF syndrome. In this review, we discussed the guidelines available for HF biomarkers, procedures for evaluating novel markers, and the utilities of both emerging and established biomarkers for risk stratification, diagnosis, and management of HF in the clinics. We later looked at how the rapidly emerging field-OMICs, can help transform HF biomarkers discoveries and establishment.

Circulating biomarkers in the early detection of hypertensive heart disease: usefulness in the developing world

Although the varying phenotypic spectra of hypertensive heart disease (HHD) can be assessed by electrocardiography (ECG), echocardiography and cardiovascular magnetic resonance (CMR), ECG criteria for left ventricular hypertrophy (LVH) are insensitive, while echocardiography and CMR are expensive, less readily available and often lack requisite expertise. Consequently, the use of circulating biomarkers in the diagnosis and prognostication of HHD beyond the traditional N-terminal pro- b-type natriuretic peptide (NT-proBNP) and B-type natriuretic peptide (BNP) have become an attractive alternative. We carried out a PubMed and Google Scholar databases' search of original articles on circulating biomarkers used in the diagnosis of the different spectrum of HHD over the last 10 years [2005-2015] in humans. Fourteen studies met the inclusion criteria with NT-pro BNP being the most studied circulating biomarker in HHD followed by soluble ST2 (sST2). There is a lack of data on the use of circulating biomarkers in HHD. There is a need to explore further this area of investigative cardiology.

Classic and Novel Biomarkers as Potential Predictors of Ventricular Arrhythmias and Sudden Cardiac Death

Sudden cardiac death (SCD), most often induced by ventricular arrhythmias, is one of the main reasons for cardiovascular-related mortality. While coronary artery disease remains the leading cause of SCD, other pathologies like cardiomyopathies and, especially in the younger population, genetic disorders, are linked to arrhythmia-related mortality. Despite many efforts to enhance the efficiency of risk-stratification strategies, effective tools for risk assessment are still missing. Biomarkers have a major impact on clinical practice in various cardiac pathologies. While classic biomarkers like brain natriuretic peptide (BNP) and troponins are integrated into daily clinical practice, inflammatory biomarkers may also be helpful for risk assessment. Indeed, several trials investigated their application for the prediction of arrhythmic events indicating promising results. Furthermore, in recent years, active research efforts have brought forward an increasingly large number of “novel and alternative” candidate markers of various pathophysiological origins. Investigations of these promising biological compounds have revealed encouraging results when evaluating the prediction of arrhythmic events. To elucidate this issue, we review current literature dealing with this topic. We highlight the potential of “classic” but also “novel” biomarkers as promising tools for arrhythmia prediction, which in the future might be integrated into clinical practice.

The Predictive Role for ST2 in Patients with Acute Coronary Syndromes and Heart Failure

Intensive research has shed light on the utilization of novel biomarkers which facilitate the diagnosis and prognosis of patients with different medical problems. One of the most important biomarkers especially in the spectrum of heart failure is soluble ST2 (sST2: soluble Suppression of Tumorigenicity 2), which is involved in inflammation, fibrosis and cardiac stress. In the revised 2017 ACC/AHA/HFSA, "Focused Update Guidelines for the Management of Heart Failure" ST2 was given a class-IIa recommendation for the optimal risk assessment in patients with heart failure. Many studies indicate that not only baseline but also serial measurements of ST2 can accurately predict future cardiovascular events in patients with Acute Coronary Syndromes and heart failure. Therefore, in this review, we are going to discuss the studies about the prognostic significance of ST2 in patients with Acute Coronary Syndromes, acute and chronic heart failure.

Independent Prognostic Value of Serum Soluble ST2 Measurements in Patients With Heart Failure and a Reduced Ejection Fraction in the PARADIGM-HF Trial (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure)

BACKGROUND

Soluble ST2 (sST2) is associated with cardiac remodeling and fibrosis. In chronic heart failure, the predictive value of sST2 has not been evaluated in a model that includes both NT-proBNP (N-terminal pro-B-type natriuretic peptide) and hs-TnT (high-sensitivity cardiac troponin T), in a trial in which treatment had a major impact. Therefore, the effects of treatment on sST2 levels in PARADIGM-HF trial (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure), the relationships between sST2 and outcomes, and the prognostic utility of various sST2 partition values were examined.

METHODS AND RESULTS

Baseline (n=2002), 1-month (n=1936), and 8-month postrandomization (n=1758) sST2 levels were compared between treatment groups (sacubitril/valsartan versus enalapril). Relationships between baseline sST2 and (1) heart failure hospitalization, (2) cardiovascular death, and (3) combined heart failure hospitalization and cardiovascular death were assessed using restricted cubic spline models. Adjusted Cox proportional hazards models were used to examine the impact of sST2 change from baseline to 1 month on the hazard of experiencing each outcome. Sacubitril/valsartan led to more reductions and fewer increases in sST2 levels versus enalapril. After adjusting for other predictors, including NT-proBNP and hs-TnT, baseline sST2 remained an independent predictor of outcomes. Associations between baseline sST2 and outcomes were linear. sST2 increases at 1 month were associated with worse subsequent outcomes and decreased with better outcomes (P=0.001, 0.012, and 0.009 for the 3 outcomes, respectively).

CONCLUSIONS

Sacubitril/valsartan resulted in greater reductions and less increases in sST2 levels than enalapril. No specific threshold was associated with risk, as linear relationships between baseline sST2 and outcomes were observed. Changes in sST2 from baseline to 1 month were independently associated with the risk of outcomes.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01035255.

Cardiac Biomarkers Predict Long-term Survival After Cardiac Surgery

BACKGROUND

Cardiac biomarkers soluble ST-2 (sST-2) and N-terminal prohormone B-type natriuretic peptide (NT-proBNP) may be associated with long-term survival after cardiac surgery. This study explored the relationship between long-term survival after cardiac surgery and serum biomarker levels.

METHODS

Patients undergoing cardiac surgery from 2004 to 2007 were enrolled in a prospective biomarker cohort in the Northern New England Cardiovascular Disease Study Group Registry. Preoperative serum biomarker levels, postoperative serum biomarker levels, and the change in serum biomarker levels were categorized by quartile. The study used Kaplan-Meier survival analysis and Cox regression models adjusted for variables in the American College of Cardiology Foundation-Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategy (ASCERT) long-term survival calculator to study the association of biomarker levels with long-term survival. After Kaplan-Meier analysis, quartiles 2 and 3 were found to have similar survival and were therefore combined into 1 category.

RESULTS

In the study cohort (n = 1648), median follow-up time was 8.5 years (interquartile range, 7.6-9.7 years), during which there were 227 deaths. The 10-year survival rate was 86%. Kaplan-Meier survival analysis demonstrated a significant (P < .001) difference across quartiles of each biomarker level measurement. After adjustment, preoperative levels, postoperative levels, and the change in biomarker levels in quartile 4 (highest serum levels or change) were significantly predictive of worse survival (hazard ratio range, 1.77-2.89; all P < .05) compared with quartile 1; however, levels of sST-2 and NT-proBNP in quartiles 2 and 3 demonstrated a nonstatistically significant trend with long-term survival.

CONCLUSIONS

Elevated preoperative and postoperative levels of sST-2 or NT-proBNP and large changes in these biomarkers' levels are associated with an increased risk of worse survival after cardiac surgery. These biomarkers can be used for risk stratification or assessing postsurgical prognosis.

Increased serum concentrations of soluble ST2 are associated with pulmonary complications and mortality in polytraumatized patients

BACKGROUND

We sought to evaluate the role of soluble ST2 (suppression of tumorigenicity) serum concentrations in polytraumatized patients and its potential role as biomarker for pulmonary complications.

METHODS

We included severely injured patients (injury severity score≥16) admitted to our level I trauma center and analyzed serum samples obtained on the day of admission and on day 2. Furthermore, patients with isolated thoracic injury and healthy probands were included and served as control groups. Serum samples were analyzed for soluble ST2 concentrations with a commercially available ELISA kit.

RESULTS

A total of 130 patients were included in the present study. Five patients with isolated thoracic injury and eight healthy probands were further included. Serum analyses revealed significantly elevated concentrations of soluble ST2 in polytraumatized patients compared to patients suffering from isolated thoracic trauma and healthy probands. In polytraumatized patients who developed pulmonary complications (acute respiratory distress syndrome and pneumonia) and in patients who died, significantly higher serum concentrations of soluble ST2 were found on day 2 (p<0.001). Serum concentrations of soluble ST2 on day 2 were of prognostic value to predict pulmonary complications in polytraumatized patients (area under the curve=0.720, 95% confidence interval=0.623-0.816). Concomitant thoracic trauma had no further impact on serum concentrations of soluble ST2.

CONCLUSIONS

Serum concentrations of soluble ST2 are upregulated following polytrauma. Increased concentrations were associated with worse outcome.

Cardiac Biomarkers in the Emergency Department: The Role of Soluble ST2 (sST2) in Acute Heart Failure and Acute Coronary Syndrome-There is Meat on the Bone

Soluble ST2 (sST2) has recently emerged as a promising biomarker in the field of acute cardiovascular diseases. Several clinical studies have demonstrated a significant link between sST2 values and patients' outcome. Further, it has been found that higher levels of sST2 are associated with an increased risk of adverse left ventricular remodeling. Therefore, sST2 could represent a useful tool that could help the risk stratification and diagnostic and therapeutic work-up of patients admitted to an emergency department. With this review, based on recent literature, we have built sST2-assisted flowcharts applicable to three very common clinical scenarios of the emergency department: Acute heart failure, type 1, and type 2 acute myocardial infarction. In particular, we combined sST2 levels together with clinical and instrumental evaluation in order to offer a practical tool for emergency medicine physicians.

Increased serum concentrations of soluble ST2 predict mortality after burn injury

Background:

Large burn injuries induce a systemic response in affected patients. Soluble ST2 (sST2) acts as a decoy receptor for interleukin-33 (IL-33) and has immunosuppressive effects. sST2 has been described previously as a prognostic serum marker. Our aim was to evaluate serum concentrations of sST2 and IL-33 after thermal injury and elucidate whether sST2 is associated with mortality in these patients.

Methods:

We included 32 burn patients (total body surface area [TBSA] >10%) admitted to our burn intensive care unit and compared them to eight healthy probands. Serum concentrations of sST2 and IL-33 were measured serially using an enzyme-linked immunosorbent assay (ELISA) technique.

Results:

The mean TBSA was 32.5%±19.6%. Six patients (18.8%) died during the hospital stay. Serum analyses showed significantly increased concentrations of sST2 and reduced concentrations of IL-33 in burn patients compared to healthy controls. In our study cohort, higher serum concentrations of sST2 were a strong independent predictor of mortality.

Conclusions:

Burn injuries cause an increment of sST2 serum concentrations with a concomitant reduction of IL-33. Higher concentrations of sST2 are associated with increased in-hospital mortality in burn patients.

Soluble ST2 and Galectin-3 and Progression of CKD

Introduction

Cardiac biomarkers soluble ST2 (sST2) and galectin-3 may reflect cardiac inflammation and fibrosis. It is plausible that these mechanisms may also contribute to the progression of kidney disease. We examined associations of sST2 and galectin-3 with kidney function decline in participants with chronic kidney disease (CKD).

Methods

This was a pooled analysis of 2 longitudinal cohorts of participants with CKD: the Clinical Phenotyping and Resource Biobank (C-PROBE) study and the Seattle Kidney Study (SKS). We measured circulating concentrations of sST2 and galectin-3 at baseline. Our primary outcome was progression to estimated glomerular filtration rate (eGFR) <15 ml/min per 1.73 m² or end-stage renal disease (ESRD). We used competing risk Cox regression models to study the association of sST2 and galectin-3 with CKD progression, adjusting for demographics, kidney function, and comorbidity.

Results

Among the 841 participants in the pooled cohort, baseline eGFR was 51 ± 27 ml/min per 1.73 m² and median urine albumin-to-creatinine ratio (UACR) was 141 (interquartile range = 15−736) mg/g. Participants with higher sST2 and galectin-3 were more likely to be older, to have heart failure and diabetes, and to have lower eGFR. Adjusting for demographics, kidney function, and comorbidity, every doubling of sST2 was not associated with progression to eGFR <15 ml/min per 1.73 m² or ESRD (adjusted hazard ratio 1.02, 95% confidence interval = 0.76−1.38). Every doubling of galectin-3 was significantly associated with a 38% (adjusted hazard ratio = 1.35, 95% confidence interval = 1.01−1.80) increased risk of progression to eGFR <15 ml/min per 1.73 m² or ESRD.

Conclusion

Higher concentrations of the cardiac biomarker galectin-3 may be associated with progression of CKD, highlighting potential novel mechanisms that may contribute to the progression of kidney disease.

Biomarkers for heart failure: small molecules with high clinical relevance

Heart failure (HF) is a rising epidemic due to the ageing population and progress in all areas of medicine. Thus, research efforts are made to ensure a timely diagnosis, to improve prognosis and treatment of the disease and to facilitate risk prediction at the population level. Because of their noninvasive determination with mostly high sensitivity and accuracy, circulating blood biomarkers are becoming increasingly important for daily clinical practice. Natriuretic peptides, especially B-type natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (Nt-proBNP) and midregional pro-atrial natriuretic peptide (MR-proANP) and cardiac troponins are established blood biomarkers in HF diagnosis and prognosis of HF-related outcomes. Inflammatory molecules as C-reactive protein (CRP) may have added value in anti-inflammatory therapy guidance. Next-generation biomarkers including soluble source of tumorigenicity 2 (sST2), growth differentiation factor-15 (GDF-15), galectin-3 (Gal-3) and diverse microribonucleic acids (miRNAs) may have additional benefit in assessment of cardiac remodeling or differentiation of HF subtypes. Multimarker approaches containing different combinations of established and novel biomarkers might improve HF risk prediction at the population level once they are used on top of clinical variables.

Soluble ST2 in Heart Failure

Suppression of tumorigenicity 2 (ST2) is a member of the interleukin (IL)-1 receptor family, whose role was originally established in the context of inflammatory and autoimmune diseases. More recently, testing for ST2 has been used in the setting of cardiovascular disease. The soluble form of ST2 is a decoy receptor that inhibits beneficial cardioprotective effects of IL-33; such inhibition results in cardiac hypertrophy, myocardial fibrosis, and ventricular dysfunction. Measurement of soluble ST2 has utility for assessing heart failure severity and prognosis. In this review, we examine the role of soluble ST2 in both acute and chronic heart failure.

Novel heart failure biomarkers: why do we fail to exploit their potential?

Plasma biomarkers are useful tools in the diagnosis and prognosis of heart failure (HF). In the last decade, numerous studies have aimed to identify novel HF biomarkers that would provide superior and/or additional diagnostic, prognostic, or stratification utility. Although numerous biomarkers have been identified, their implementation in clinical practice has so far remained largely unsuccessful. Whereas cardiac-specific biomarkers, including natriuretic peptides (ANP and BNP) and high sensitivity troponins (hsTn), are widely used in clinical practice, other biomarkers have not yet proven their utility. Galectin-3 (Gal-3) and soluble suppression of tumorigenicity 2 (sST2) are the only novel HF biomarkers that are included in the ACC/AHA HF guidelines, but their clinical utility still needs to be demonstrated. In this review, we will describe natriuretic peptides, hsTn, and novel HF biomarkers, including Gal-3, sST2, human epididymis protein 4 (HE4), insulin-like growth factor-binding protein 7 (IGFBP-7), heart fatty acid-binding protein (H-FABP), soluble CD146 (sCD146), interleukin-6 (IL-6), growth differentiation factor 15 (GDF-15), procalcitonin (PCT), adrenomedullin (ADM), microRNAs (miRNAs), and metabolites like 5-oxoproline. We will discuss the biology of these HF biomarkers and conclude that most of them are markers of general pathological processes like fibrosis, cell death, and inflammation, and are not cardiac- or HF-specific. These characteristics explain to a large degree why it has been difficult to relate these biomarkers to a single disease. We propose that, in addition to clinical investigations, it will be pivotal to perform comprehensive preclinical biomarker investigations in animal models of HF in order to fully reveal the potential of these novel HF biomarkers.

Increased soluble ST2 and IL‑4 serum levels are associated with disease severity in patients with membranous nephropathy

The interleukin (IL)‑33/suppression of tumorigenicity 2 (ST2) axis regulates Th2 reactivity, and ST2 is the receptor for IL‑33. In this study, the roles of IL‑33 and soluble ST2 (sST2) in the pathogenesis of membranous nephropathy (MN), and their association with disease severity were evaluated. Serum levels of IL‑33 and sST2 in 93 patients, and 34 healthy controls (HCs) were measured by enzyme‑linked immunosorbent assays. Clinical characteristics were recorded and the estimated glomerular filtration rates (eGFRs) were computed. In addition, the association between serum IL‑33 and sST2 levels, and clinical measurements in patients with MN was analyzed. No difference in the serum levels of IL‑33 was identified between the patients with MN and HCs. However, the serum levels of sST2 were considerably higher in the MN patients compared with in the HCs at every stage. Higher concentrations of serum IL‑2, IL‑4, IL‑10, IL‑17A, and IFN‑γ were measured in the MN patients compared with in the HCs. Serum sST2 concentrations were negatively correlated with IL‑4 concentrations in the patients with MN. Furthermore, serum sST2 levels were negatively correlated with the eGFRs and serum calcium levels. Serum sST2 levels, but not IL‑33 levels, were positively correlated with the 24‑h urine protein and serum phosphorus levels. Following treatment, serum sST2 levels were considerably reduced, whereas serum IL‑4 and IL‑10 levels were significantly increased. These data suggest that sST2 and IL‑4, but not IL‑33, contribute to the pathogenesis of MN.

Contemporary Risk Stratification After Myocardial Infarction in the Community: Performance of Scores and Incremental Value of Soluble Suppression of Tumorigenicity-2

BACKGROUND

Current American Heart Association/American College of Cardiology guidelines recommend the GRACE (Global Registry of Acute Coronary Events) and TIMI (Thrombolysis in Myocardial Infarction) scores to assess myocardial infarction (MI) prognosis. Changes in the epidemiological characteristics of MI and the availability of new biomarkers warrant an assessment of the performance of these scores in contemporary practice. We assessed the following: (1) the performance of GRACE and TIMI to predict 1-year mortality in a cohort of patients stratified by ST-segment elevation MI (STEMI) and non-STEMI (NSTEMI) and (2) the incremental discriminatory power of soluble suppression of tumorigenicity-2, a myocardial fibrosis biomarker.

METHODS AND RESULTS

Olmsted County, Minnesota, residents with incident MI (N=1401) were recruited prospectively from November 1, 2002 to December 31, 2012 (mean age, 67 years; 61% men; 79% with NSTEMI). Baseline data were used to calculate risk scores; soluble suppression of tumorigenicity-2 was measured in stored plasma samples obtained at index MI. C-statistics adapted to survival data were used to assess the discriminatory power of the risk scores and the improvement gained by adding other markers. During the first year of follow-up, 190 patients (14%) died. The discriminatory performance to predict death was reasonable for GRACE and poor for TIMI, and was generally worse in those with NSTEMI versus those with STEMI. In people with NSTEMI, sequential addition of comorbidities and soluble suppression of tumorigenicity-2 substantially improved the c-statistic over GRACE (from 0.78 to 0.80 to 0.84) and TIMI (from 0.61 to 0.73 to 0.81), respectively (all P≤0.05).

CONCLUSIONS

Guideline-recommended scores for risk assessment after MI underperform in contemporary community patients, particularly those with NSTEMI, which now represents most infarcts. Incorporating comorbidities and soluble suppression of tumorigenicity-2 substantially improves risk prediction, thereby delineating opportunities to improve clinical care.

Soluble ST2 correlates with some indicators of right ventricular function in hypertensive heart failure

Purpose

ST2 receptor, which is a member of the Toll-like/interleukin-1 (IL-1) receptor family, has been found to be increased in the serum of patients 1 day after myocardial infarction. Several other studies have shown that soluble ST2 levels correlate with severity of heart failure (HF), left ventricular ejection fraction, creatinine clearance, B-type natriuretic peptide and C-reactive protein, and are predictors of mortality in HF. Most of these studies were not only limited to ischemic heart disease but also concentrated on left-sided HF. We therefore decided to study the relationship between soluble ST2 and some markers of right ventricular (RV) function in a cohort of hypertensive HF subjects.

Patients and methods

This is a prospective cohort study of hypertensive HF patients presenting to the University of Abuja Teaching Hospital, Abuja, over a 12-month period. ST2 was measured in plasma sample by the enzyme-linked immunosorbent assay (ELISA) method. Right ventricular diameters in diastole (RVDD) and right atrial area (RAA) were obtained on echocardiography, while right ventricular systolic pressure (RVSP) was estimated from echocardiography by the addition of the pressure gradient between the right ventricle and right atrium (RA) to the pressure in the RA.

Results

There was a significant correlation between RVSP and soluble ST2 (t=0.75, p<0.0001), RVDD (t=0.28, p=0.004) and RAA (t=0.46, p=0.002).

Conclusion

In a cohort of hypertensive HF subjects, soluble ST2 correlates significantly with RVSP, RVDD and RAA.

Prognostic role of soluble suppression of tumorigenicity-2 on cardiovascular mortality in outpatients with heart failure

Objective:

Soluble suppression of tumorigenicity-2 (sST2), a member of the interleukin 1 receptor family, is increased in mechanical stress conditions and is produced by cardiomyocytes and cardiac fibroblasts. Elevated sST2 level is associated with the prognosis of acute coronary syndrome, pulmonary arterial hypertension, and acute and chronic heart failure (HF). In this study, we aimed to investigate the relationship between sST2 levels and cardiovascular mortality in outpatients with HF.

Methods:

This study used a prospective observational cohort design. A total of 130 consecutive outpatients with HF were prospectively evaluated. Clinical characteristics, laboratory results, cardiovascular risk factors, comorbidities, and medication use were recorded. The patients were followed up for a mean period of 12±4 months for the development of cardiovascular death. They were classified into two groups: those who survived and those who died.

Results:

Mean age of patients was 67±11 years (69% males). After follow-up, 23 of 130 patients (18%) experienced cardiovascular death. sST2 levels were higher among those who died compared with among those who survived [51 (21–162) vs. 27 (9–198) ng/mL, p<0.001]. Optimal cut-off sST2 level to predict cardiovascular mortality was found to be >30 ng/mL with a sensitivity of 87% and a specificity of 67% (AUC =0.808, 95% CI=0.730 to 0.872). sST2 levels were negatively correlated with left ventricular ejection fraction and triglyceride, total cholesterol, LDL cholesterol, and hemoglobin levels and were positively correlated with left atrium size and the presence of right ventricular dilatation. In multiple Cox regression analysis, sST2 level of >30 ng/mL (HR=6.756, p=0.002, 95% CI=1.983–23.018), hemoglobin level (HR=0.705, p<0.001, 95% CI=0.587–0.847), age (HR=1.050, p=0.013, 95% CI=1.010–1.091), and HDL cholesterol level (HR=0.936, p=0.010, 95% CI=0.889–0.984) remained to be associated with an increased risk of mortality.

Conclusion:

sST2 measurement could help risk stratification in outpatients with HF. Moreover, this is the first study describing the impact of sST2 protein in Turkish patients with HF.

Soluble ST2 predicts outcome and hemorrhagic transformation after acute stroke

Objective

ST2 is a member of the toll‐like receptor superfamily that can alter inflammatory signaling of helper T‐cells. We investigated whether soluble ST2 (sST2) could independently predict outcome and hemorrhagic transformation (HT) in the setting of stroke.

Methods

We measured sST2 in patients enrolled in the Specialized Program of Translational Research in Acute Stroke (SPOTRIAS) network biomarker study. 646 patients had plasma samples collected at the time of hospital admission and 210 patients had a second sample collected 48 h after stroke onset. Functional outcome was assessed using the modified Rankin Scale (mRS), with good and poor outcomes defined as mRS 0‐2 and 3‐6, respectively. HT was classified using ECASS criteria. The relationships between sST2, outcome, and HT were evaluated using multivariable logistic regression, Kaplan–Meier survival analysis and receiver operating characteristic curves.

Results

646 patients were included in the analysis (mean age 69 years; 44% women), with a median NIHSS of 5 [IQR: 2–12]. The median sST2 level on hospital admission was 35.0 ng/mL [IQR: 25.7–49.8 ng/mL] and at 48 h it was 37.4 ng/mL [IQR 27.9–55.6 ng/mL]. sST2 was independently associated with poor outcome (OR: 2.77, 95% CI: 1.54–5.06; P = 0.003) and mortality (OR: 3.56, 95% CI: 1.58–8.38, P = 0.001) after multivariable adjustment. Plasma sST2 was also associated with hemorrhagic transformation after adjustment for traditional risk factors (OR: 5.58, 95% CI: 1.40–37.44, P = 0.039).

Interpretation

Soluble ST2 may serve as a prognostic biomarker for outcome and hemorrhagic transformation in patients with acute stroke. ST2 may link neuroinflammation and secondary injury after stroke.

Association of soluble ST2 with functional capacity in outpatients with heart failure

BACKGROUND

Biomarkers play an important role in the risk stratification of patients with heart failure (HF). Recent studies have shown that soluble suppression of tumorigenicity 2 (sST2), a member of the interleukin 1 receptor family, is associated with disease prognosis in acute and chronic HF. In this study we aimed to investigate the relation between sST2 level and functional capacity in outpatients with systolic HF.

PATIENTS AND METHODS

This study included 120 HF patients with reduced ejection fraction (HFrEF; EF ≤ 40%). The mean age of patients was 66 ± 11 years. Advanced HF (New York Heart Association [NYHA] functional class III-IV) was observed in 35 patients (29%).

RESULTS

sST2 levels were on average higher in patients with NYHA functional classes III and IV than in patients with NYHA functional classes I and II (51 [9-198] vs. 25 ng/ml [9-118], p < 0.001). In a multiple logistic regression model, sST2 level (OR: 1.044, p = 0.004, 95% CI: 1.014-1.075), hemoglobin level (OR: 0.590, p = 0.001, 95% CI: 0.433-0.805), total cholesterol level (OR: 0.977, p = 0.004, 95% CI: 0.962-0.993), and age (OR: 1.066, p = 0.047, 95% CI: 1.001-1.136) were associated with poor functional capacity. In receiver operating characteristic (ROC) curve analysis, the optimal cut-off value of sST2 for predicting poor functional capacity was >42 ng/ml, with 63% sensitivity and 88% specificity (AUC: 0.810, 95% CI: 0.728- 0.875).

CONCLUSION

Higher sST2 levels were strongly associated with poor NYHA functional class, independent of cardiac risk factors, in outpatients with HFrEF.

Role of Biomarkers for the Prevention, Assessment, and Management of Heart Failure: A Scientific Statement From the American Heart Association

BACKGROUND AND PURPOSE

Natriuretic peptides have led the way as a diagnostic and prognostic tool for the diagnosis and management of heart failure (HF). More recent evidence suggests that natriuretic peptides along with the next generation of biomarkers may provide added value to medical management, which could potentially lower risk of mortality and readmissions. The purpose of this scientific statement is to summarize the existing literature and to provide guidance for the utility of currently available biomarkers.

METHODS

The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through December 2016. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or contemporary clinical practice recommendations.

RESULTS

A number of biomarkers associated with HF are well recognized, and measuring their concentrations in circulation can be a convenient and noninvasive approach to provide important information about disease severity and helps in the detection, diagnosis, prognosis, and management of HF. These include natriuretic peptides, soluble suppressor of tumorgenicity 2, highly sensitive troponin, galectin-3, midregional proadrenomedullin, cystatin-C, interleukin-6, procalcitonin, and others. There is a need to further evaluate existing and novel markers for guiding therapy and to summarize their data in a standardized format to improve communication among researchers and practitioners.

CONCLUSIONS

HF is a complex syndrome involving diverse pathways and pathological processes that can manifest in circulation as biomarkers. A number of such biomarkers are now clinically available, and monitoring their concentrations in blood not only can provide the clinician information about the diagnosis and severity of HF but also can improve prognostication and treatment strategies.

Serum Galectin-3 and ST2 as predictors of unfavorable outcome in stable dilated cardiomyopathy patients

Dilated cardiomyopathy (DCM) is the third cause of heart failure and the most frequent cause of heart transplantation (HT). The value of biomarkers in prognostic stratification may be important to identification the patients for more advanced treatment. Assessment of serum Galectin-3 (Gal-3) and ST2 as biomarkers of unfavorable outcome (death and combined endpoint: HT or death or left ventricular assist device implantation) in stable DCM patients. 107 DCM patients age 39-56 years were included into the study and followed-up for mean 4.8 years. Gal-3 and ST2 concentrations were measured ELISA tests. Clinical data, treatment, laboratory parameters, NT-proBNP, Gal-3 and ST2 measured at time of inclusion were assessed as risk factors for reaching the study endpoints using log rank test and Cox proportional-hazards model. During follow-up 27 patients died, 40 achieved combined endpoint. ROC curves indicated cut-off value of ST2-17.53 ng/ml, AUC-0.65 (0.53-0.76) and of NT-proBNP-669 pg/ml, AUC 0.61 (0.50-0.73) for prediction of death. In multivariate analysis ST2 was predictor of death (HR per unit increase in log ST2 2.705, 95 % CI 1.324-5.528, P=0.006) and combined endpoint (HR per unit increase in log ST2 2.753, 95 % CI 1.542-4.914, P<0.001). NT-proBNP was predictive variable only for death in multivariate analysis. Gal-3 concentration was not associated with adverse outcome. ST2 but not Gal-3 may be useful for predicting adverse outcome in stable dilated cardiomyopathy patients.

Soluble ST2 predicts 1-year outcome in patients undergoing transcatheter aortic valve implantation

BACKGROUND

Soluble ST2 (sST2) has been introduced as a novel biomarker in patients suffering from heart failure for risk stratification. In this study, we sought to investigate whether sST2 is useful for risk stratification and prediction of mortality in patients undergoing transcatheter aortic valve implantation (TAVI).

MATERIALS AND METHODS

A total of 274 patients undergoing TAVI were included in this study (149 female; age 81 ± 1 years; EUROSCORE 25 ± 1; STS score 3·8 ± 0·2). Plasma samples were obtained preinterventional and analysed for sST2. Patients were followed up 1 month and 1 year after TAVI.

RESULTS

In a Cox regression analysis, sST2 plasma concentration was associated with increased mortality (changes per pg/mL sST2 concentration; HR 1·00006 95% (1·00004-1·00009); P < 0·001). A cut-off by means of the Youden Index was calculated (10 070·27 pg/mL), and patients were retrospectively divided into two cohorts, in those above (31·3%) and those below (68·7%) this value. These two groups were then compared regarding mortality both after 30 days and 1 year: whereas 1-month mortality did not differ (7·0% vs. 10·3%, OR 1·50 95% CI (0·60-3·79; P = 0·46)), patients with a sST2 concentration above the cut-off of 10 070·27 pg/mL showed a significantly worse outcome after 1 year (49·2% vs. 23·2%; OR 3·21 95% CI (1·70-6·04); P < 0·001). After correction for confounders in a multivariate Cox regression analysis, sST2 (1·0002 95% CI (1·0001-1·0003); P = 0·001) concentration remained associated with mortality.

CONCLUSIONS

sST2 levels were associated with 1-year mortality after TAVI. Based on these results, we assume that sST2 might help to identify patients at high risk for death in whom conservative treatment should be considered.

Serum Levels of Soluble ST2 and IL-10 Are Associated with Disease Severity in Patients with IgA Nephropathy

Background. The IL-33/ST2 axis is involved in humoral immune responses. Method. The concentrations of sera IL-33 and sST2 in 74 patients and 34 healthy controls (HC) were measured by ELISA. Clinical and laboratory data were examined. The potential association between sera IL-33 and sST2 and the clinical parameters in IgAN patients were analyzed. Results. No difference was discovered in IL-33 concentrations between IgAN patients and HCs; however, the sST2 were significantly higher in each stage of IgAN progression than in the HC. The concentration of sST2 was positively correlated with IL-33 levels in IgAN patients. Higher levels of sera IL-2, IL-4, IL-10, IL-17A, and IFN-γ were detected in patients compared to the HC. The concentration of serum sST2 was positively correlated with the levels of IL-10 in IgAN patients. Furthermore, serum sST2 was negatively correlated with the values of eGFR and serum calcium. Serum sST2 was positively correlated with 24-hour urinary protein, serum phosphorus, and serum IgA; however, serum IL-33 was not associated with these. Following treatment, serum sST2 was significantly decreased, while sera IL-4 and IL-10 were significantly increased. Conclusions. Increased sST2 and IL-10 but not IL-33 may be involved in the pathogenic process of IgAN.

The Counter-Regulation of Atherogenesis: a Role for Interleukin-33

The recently recognized cytokine interleukin-33 and its receptor ST2 play a favorable role during atherogenesis by inducing a Th1→Th2 shift of the immune response. IL-33 also protects the failing human heart from harmful biomechanical forces which lead to cardiomyocyte hypertrophy and exaggerated interstitial fibrosis. IL-33 inevitably displays side effects common to other Th2 cytokines, the most grave of which is a predisposition to allergic reactions. IL-33 is a nuclear transcription factor of endothelial cells. As such, it is abundant in nonproliferating vessels. Its down-regulation is required for angiogenesis, which may be profitable in wound healing or deleterious in tumor growth.

Biomarkers for Heart Failure: An Update for Practitioners of Internal Medicine

Biomarkers have become an integral part of practicing medicine, especially in heart failure. The natriuretic peptides are commonly used in the evaluation of heart failure, but their role extends beyond diagnosis and includes risk stratification and management of heart failure patients. Newer biomarkers have arrived and are becoming part of routine care of heart failure patients. Both ST2 and high-sensitivity troponin have significant prognostic value for mortality, but also may assist in the titration of medical therapy. Procalcitonin can help guide appropriate antibiotic use in patients with heart failure. The ability to appropriately use and interpret these biomarkers is imperative to the care of heart failure patients, especially as these newer biomarkers become widely used.

Elevated ST2 Distinguishes Incidences of Pediatric Heart and Small Bowel Transplant Rejection

Elevated serum soluble (s) suppressor of tumorigenicity-2 is observed during cardiovascular and inflammatory bowel diseases. To ascertain whether modulated ST2 levels signify heart (HTx) or small bowel transplant (SBTx) rejection, we quantified sST2 in serially obtained pediatric HTx (n = 41) and SBTx recipient (n = 18) sera. At times of biopsy-diagnosed HTx rejection (cellular and/or antibody-mediated), serum sST2 was elevated compared to rejection-free time points (1714 ± 329 vs. 546.5 ± 141.6 pg/mL; p = 0.0002). SBTx recipients also displayed increased serum sST2 during incidences of rejection (7536 ± 1561 vs. 2662 ± 543.8 pg/mL; p = 0.0347). Receiver operator characteristic (ROC) analysis showed that serum sST2 > 600 pg/mL could discriminate time points of HTx rejection and nonrejection (area under the curve [AUC] = 0.724 ± 0.053; p = 0.0003). ROC analysis of SBTx measures revealed a similar discriminative capacity (AUC = 0.6921 ± 0.0820; p = 0.0349). Quantitative evaluation of both HTx and SBTx biopsies revealed that rejection significantly increased allograft ST2 expression. Pathway and Network Analysis of biopsy data pinpointed ST2 in the dominant pathway modulated by rejection and predicted tumor necrosis factor-α and IL-1β as upstream activators. In total, our data indicate that alloimmune-associated pro-inflammatory cytokines increase ST2 during rejection. They also demonstrate that routine serum sST2 quantification, potentially combined with other biomarkers, should be investigated further to aid in the noninvasive diagnosis of rejection.

Soluble ST2 Testing: A Promising Biomarker in the Management of Heart Failure

ST2 is a member of the interleukin-1 receptor family biomarker and circulating soluble ST2 concentrations are believed to reflect cardiovascular stress and fibrosis. Recent studies have demonstrated soluble ST2 to be a strong predictor of cardiovascular outcomes in both chronic and acute heart failure. It is a new biomarker that meets all required criteria for a useful biomarker. Of note, it adds information to natriuretic peptides (NPs) and some studies have shown it is even superior in terms of risk stratification. Since the introduction of NPs, this has been the most promising biomarker in the field of heart failure and might be particularly useful as therapy guide.