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

Association of microRNA-210-3p with NT-proBNP, sST2, and Galectin-3 in heart failure patients with preserved and reduced ejection fraction: A cross-sectional study

BACKGROUND

Heart failure (HF) is a growing health problem and around two percent are affected in the general population. Accurate diagnostic markers that have the potential for early diagnosis of HF are lacking. This study aimed to compare the expression levels of microRNA-210-3p with biomarkers NT-proBNP, sST2, and galectin-3, in heart failure patients with preserved and reduced ejection fractions.

MATERIALS AND METHODS

The cross-sectional study was conducted on 270 hypertensive heart failure patients in the age group of 30 to 75 years of both genders. The participants with evidence of HF were recruited from the Department of Cardiology in a tertiary care hospital in Chennai, India. MicroRNA-210-3p was analyzed by qRT-PCR in a stratified sample of 80 HF patients and 20 apparently healthy individuals. Biomarkers were analyzed by ELISA. Institutional ethics committee approval and written informed consent were obtained. Statistical analysis was performed using R software (4.2.1). Based on the type of distribution of data, appropriate statistical tools were used. p-value ≤  0.05 was considered to be statistically significant.

RESULTS

All the biomarkers including microRNA-210-3p were significantly higher in HFrEF than in HFpEF. MAGGIC score showed a positive correlation with all the biomarkers. The cut-off of microRNA-210-3p was 5.03.

CONCLUSION

All the biomarkers were significantly elevated in HFrEF compared to HFpEF. However, microRNA-210-3p could be an early marker in the diagnosis of heart failure. The strategy of employing a multi-marker approach could help in the early diagnosis as well as in stratifying the HF patients.

Innovations in heart failure management: The role of cutting-edge biomarkers and multi-omics integration

Heart failure (HF) remains a major cause of morbidity and mortality worldwide and represents a major challenge for diagnosis, prognosis and treatment due to its heterogeneity. Traditional biomarkers such as BNP and NT-proBNP are valuable but insufficient to capture the complexity of HF, especially phenotypes such as HF with preserved ejection fraction (HFpEF). Recent advances in multi-omics technology and novel biomarkers such as cell-free DNA (cfDNA), microRNAs (miRNAs), ST2 and galectin-3 offer transformative potential for HF management. This review explores the integration of these innovative biomarkers into clinical practice and highlights their benefits, such as improved diagnostic accuracy, enhanced risk stratification and non-invasive monitoring capabilities. By leveraging multi-omics approaches, including lipidomics and metabolomics, clinicians can uncover new pathways, refine the classification of HF phenotypes, and develop personalized therapeutic strategies tailored to individual patient profiles. Remarkable advances in proteomics and metabolomics have identified biomarkers associated with key HF mechanisms such as mitochondrial dysfunction, inflammation and fibrosis, paving the way for targeted therapies and early interventions. Despite the promising results, significant challenges remain in translating these findings into routine care, including high costs, technical limitations and the need for large-scale validation studies. This report argues for an integrative, multi-omics-based model to overcome these obstacles and emphasizes the importance of collaboration between researchers, clinicians and policy makers. By linking innovative science with practical applications, multi-omics approaches have the potential to redefine HF management and lead to better patient outcomes and more sustainable healthcare systems.

Short-term predictive value of sST2 in patients with STEMI following primary PCI: a prospective observational study

AIM

The objective of this study was to investigate the level of soluble suppression of tumorigenicity-2 (sST2) in patients with acute ST-segment elevation myocardial infarction (STEMI) following primary percutaneous coronary intervention (PCI), and to provide a new biomarker for clinical management and prognosis assessment.

METHOD

This was a prospective study. 148 STEMI patients following primary PCI were enrolled and divided into 2 groups by the median value of sST2 and afterwards followed up for 30 days to access the occurrence of major adverse cardiac events (MACEs), which were defined as cardiovascular death, heart failure and recurrent MI.

RESULTS

sST2 ranged from 20.57 to 98.96 ng/mL. High sST2 group had higher MACEs rate compared to low sST2 group (28.8% vs. 8.0%, P = 0.001). sST2 was positively correlated with age (r = 0.181, P = 0.027), SYNTAX score (r = 0.257, P = 0.002), high-sensitive C-reactive protein (hs-CRP) (r = 0.225, P = 0.006), B-type natriuretic peptide (BNP) (r = 0.225, P = 0.006) and negatively with left ventricle ejection fraction (LVEF) (r = -0.197, P = 0.016). After adjustment for clinical variables, sST2 level (OR 3.680, P = 0.015) and LVEF (OR 0.880, P < 0.001) remained independent predictors of 30-days MACEs. In receiver operating characteristic curve (ROC) analyses, the area under the curve (AUC) of sST2 for predicting 30-days MACEs was 0.755(P < 0.001). The AUC of sST2 combining hs-CRP and LVEF for prediction was 0.828(95%CI [0.743-0.912], P < 0.001).

CONCLUSION

sST2 level after primary PCI was an independent risk factor of MACEs in STEMI patients through 30 days follow-up.

The Role and Implications of COVID-19 in Incident and Prevalent Heart Failure

PURPOSE OF REVIEW

This review examines the pathophysiological interactions between COVID-19 and heart failure, highlighting the exacerbation of heart failure in COVID-19 patients. It focuses on the complex mechanisms driving worse outcomes in these patients.

RECENT FINDINGS

Patients with pre-existing heart failure experience more severe symptoms and higher mortality rates due to mechanisms such as cytokine storms, myocardial infarction, myocarditis, microvascular dysfunction, thrombosis, and stress cardiomyopathy. Elevated biomarkers like troponin and natriuretic peptides correlate with severe disease. Long-term cardiovascular risks for COVID-19 survivors include increased incidence of heart failure, non-ischemic cardiomyopathy, cardiac arrest, and cardiogenic shock. COVID-19 significantly impacts patients with pre-existing heart failure, leading to severe symptoms and higher mortality. Elevated cardiac biomarkers are indicators of severe disease. Acute and long-term cardiovascular complications are common, calling for ongoing research into targeted therapies and improved management strategies to better prevent, diagnose, and treat heart failure in the context of COVID-19.

Multi-Marker Approach in Patients with Acute Chest Pain in the Emergency Department

BACKGROUND

Chest pain is a prevalent reason for emergency room referrals and presents diagnostic challenges. The physician must carefully differentiate between cardiac and noncardiac causes, including various vascular and extracardiovascular conditions. However, it is crucial not to overlook serious conditions such as acute coronary syndrome (ACS). Diagnosis of acute myocardial infarction (AMI) and early discharge management become difficult when traditional clinical criteria, ECG, and troponin values are insufficient. Recently, the focus has shifted to a "multi-marker" approach to improve diagnostic accuracy and prognosis in patients with chest pain.

METHODS

This observational, prospective, single-center study involved, with informed consent, 360 patients presenting to the emergency department with typical chest pain and included a control group of 120 healthy subjects. In addition to routine examinations, including tests for hsTnI (Siemens TNIH kit), according to the 0-1 h algorithm, biochemical markers sST2 (tumorigenicity suppression-2) and suPAR (soluble urokinase plasminogen activator receptor) were also evaluated for each patient. A 12-month follow-up was conducted to monitor outcomes and adverse events.

RESULTS

We identified two groups of patients: a positive one (112 patients) with high levels of hsTnI, sST2 > 24.19 ng/mL, and suPAR > 2.9 ng/mL, diagnosed with ACS; and a negative one (136 patients) with low levels of hsTnI, suPAR < 2.9 ng/mL, and sST2 < 24.19 ng/mL. During the 12-month follow-up, no adverse events were observed in the negative group. In the intermediate group, patients with hsTnI between 6 ng/L and the ischemic limit, sST2 > 29.1 ng/mL and suPAR > 2.9 ng/mL, showed the highest probability of adverse events during follow-up, while those with sST2 < 24.19 ng/mL and suPAR < 2.9 ng/mL had a better outcome with no adverse events at 12 months.

CONCLUSION

Our data suggest that sST2 and suPAR, together with hsTnI, may be useful in the prognosis of cardiovascular patients with ACS, providing additional information on endothelial damage. These biomarkers could guide the clinical decision on further diagnostic investigations. In addition, suPAR and sST2 emerge as promising for event prediction in patients with chest pain. Their integration into the standard approach in PS could facilitate more efficient patient management, allowing safe release or timely admission based on individual risk.

Soluble ST2 in Heart Failure: A Clinical Role beyond B-Type Natriuretic Peptide

Soluble (s)ST2 has been proposed as a useful biomarker for heart failure (HF) patient management. Myocardial damage or mechanical stress stimulate sST2 release. ST2 competes with a membrane bound receptor (ST2 ligand, or ST2L) for interleukin-33 (IL-33) binding, inhibiting the effects induced by the ST2L/IL-33 interaction so that excessive sST2 may contribute to myocardial fibrosis and ventricular remodeling. Compared to natriuretic peptides (NPs), sST2 concentration is not substantially affected by age, sex, body mass index, kidney function, atrial fibrillation, anemia, or HF etiology, and has low intra-individual variation. Its prognostic role as an independent marker is well reported in the literature. However, there is a gap on its use in combination with NPs, currently the only biomarkers recommended by European and American guidelines for HF management. Reflecting the activation of two distinct biological systems, a benefit from the use of sST2 and NP in combination is advocated. The aim of this review is to report the current scientific knowledge on sST2 in the acute and chronic HF settings with a particular attention to its additive role to natriuretic peptides (NPs).

Novel Biomarkers and Their Role in the Diagnosis and Prognosis of Acute Coronary Syndrome

The burden of cardiovascular diseases and the critical role of acute coronary syndrome (ACS) in their progression underscore the need for effective diagnostic and prognostic tools. Biomarkers have emerged as crucial instruments for ACS diagnosis, risk stratification, and prognosis assessment. Among these, high-sensitivity troponin (hs-cTn) has revolutionized ACS diagnosis due to its superior sensitivity and negative predictive value. However, challenges regarding specificity, standardization, and interpretation persist. Beyond troponins, various biomarkers reflecting myocardial injury, neurohormonal activation, inflammation, thrombosis, and other pathways are being explored to refine ACS management. This review article comprehensively explores the landscape of clinically used biomarkers intricately involved in the pathophysiology, diagnosis, and prognosis of ACS (i.e., troponins, creatine kinase MB (CK-MB), B-type natriuretic peptides (BNP), copeptin, C-reactive protein (CRP), interleukin-6 (IL-6), d-dimers, fibrinogen), especially focusing on the prognostic role of natriuretic peptides and of inflammatory indices. Research data on novel biomarkers (i.e., endocan, galectin, soluble suppression of tumorigenicity (sST2), microRNAs (miRNAs), soluble oxidized low-density lipoprotein receptor-1 (sLOX-1), F2 isoprostanes, and growth differentiation factor 15 (GDF-15)) are further analyzed, aiming to shed light on the multiplicity of pathophysiologic mechanisms implicated in the evolution of ACS. By elucidating the complex interplay of these biomarkers in ACS pathophysiology, diagnosis, and outcomes, this review aims to enhance our understanding of the evolving trajectory and advancements in ACS management. However, further research is necessary to establish the clinical utility and integration of these biomarkers into routine practice to improve patient outcomes.

Significance of sTREM-1 and sST2 combined diagnosis for sepsis detection and prognosis prediction

The diagnosis of sepsis still lacks a practical and reliable gold standard. The purpose of this study was to confirm the effect of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) combined with soluble suppression of tumorigenicity 2 (sST2) in the diagnosis of sepsis through the correlation between sTREM-1, sST2, and sequential organ failure assessment (SOFA) scores. Baseline data of 91 patients with sepsis in the intensive care unit were collected, sTREM-1 and sST2 were detected, and the correlation between markers and SOFA score was analyzed. Besides, the prognostic value of baseline and postadmission indicators for sepsis was analyzed with death as the outcome. The results showed that the expressions of sST2 and sTREM-1 in death group and survival group were higher than those in the survival group (p < 0.05). Correlation analysis showed that sST2, sTREM-1, and the joint diagnosis model had a high correlation with SOFA score (p < 0.05), but poor correlation with Acute Physiology and Chronic Health Evaluation Ⅱ score (p > 0.05). Among them, joint diagnosis model has the highest correlation. Receiver operating characteristic curve analysis showed that combined diagnosis had higher area under curve values. sTREM-1/sST2 can be better used in the diagnosis of sepsis than the single biomarker detection, and the combination of the above two biomarkers has potential application value in the detection and prognosis prediction of sepsis.

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.

Incidence and Severity of Acute Myocardial Injury after Thoracic Surgery: Effects of Nicorandil

Aim. To study the perioperative dynamics of myocardial injury biomarkers high-sensitivity cardiac troponin I (hs-cTnI), ischemia-modified albumin (IMA) and soluble ST2 (sST2) when taking nicorandil in lung cancer patients with concomitant coronary heart disease (CHD) undergoing surgical lung resection.

Material and methods. The study included 54 patients (11 women and 43 men) with non-small cell lung cancer and concomitant stable CHD who underwent lung resection in the volume of lobectomy or pneumonectomy. Patients were randomly assigned to the nicorandil group (oral administration 10 mg BID for 7 days before and 3 days after surgery; n=27) and the control group (n=27). In the study groups, the perioperative dynamics of hscTnI, IMA and sST2, determined in the blood before and 24 and 48h after surgery, were compared. We calculated the incidence of acute myocardial injury in the groups, which was diagnosed in cases of postoperative hs-cTnI increase of more than one 99th percentile of the upper reference limit. The associations of nicorandil intake and acute myocardial injury were evaluated.

Results. The groups were comparable in gender, age, basic clinical characteristics, as well as baseline levels of myocardial injury biomarkers. After the intervention, both samples showed an increase in the hs-cTnI and sST2 levels and a decrease in IMA concentration (all p<0.02 for related group differences). In the nicorandil group, in comparison with the control one, 48h after surgery, we found lower mean levels of hs-cTnI [16.7 (11.9;39.7) vs 44.3 (15.0;130.7) ng/l; p<0.05) and sST2 [62.8 (43.6;70.1) vs 76.5 (50.2;87.1) ng/ml; p<0.05), concentration increase rates of hs-cTnI [14.8 (0.7;42.2) vs 32.5 (14.0;125.0) ng/l; p<0.01) and sST2 [24.4 (10.3;42.4) vs 47.4 (17.5;65.3) ng/ml; p<0.05), as well as highest concentrations for the entire postoperative period of hs-cTnI [30.7 (12.0;53.7) vs 79.0 (20.3;203.3) ng/L, p<0.01] and sST2 [99.8 (73.6;162.5) vs 147.8 (87.8;207.7) ng/mL; p<0.05]. The serum IMA decreased when taking nicorandil to a greater extent [-8.0 (-12.6; -2.0) vs -2.7 (-6.0; +5.5) ng/ ml; p<0.01] 24h after surgery. Acute myocardial injury was diagnosed in 7 people in the nicorandil group (25.9%) and in 15 in the control one (55.6%; pχ2=0.027). The adjusted odds ratio of acute myocardial injury when taking nicorandil was 0.35 (95% confidence interval 0.15-0.83, p=0.017).

Conclusion. Taking  nicorandil  in patients with lung cancer and concomitant CHD  who underwent  surgical  lung resection is associated  with a lower postoperative  increase in hs-cTnI  and sST2  and a reduced risk of acute myocardial  injury, which may indicate the cardioprotective effect of nicorandil under acute surgical stress conditions.

Low-Volume and High-Intensity Aerobic Interval Training May Attenuate Dysfunctional Ventricular Remodeling after Myocardial Infarction: Data from the INTERFARCT Study

Background

Aerobic high-intensity interval training (HIIT) has demonstrated benefits for ventricular remodeling after myocardial infarction (MI) through various mechanisms. Despite this, the optimal training volume is not well known. The present study aimed to assess the effects of different (low vs. high volume) aerobic HIIT compared to an attentional control (AC) group on echocardiographic and biochemical indicators of left ventricular (LV) remodeling in adults after MI.

Methods

Randomized clinical trial conducted on post-MI patients with preserved ventricular function. Participants were assigned to three study groups. Two groups performed HIIT 2 d/week, one group with low-volume HIIT (20 min, n = 28) and another with high-volume HIIT (40 min, n = 28). A third group was assigned to AC (n = 24) with recommendations for unsupervised aerobic training. Left ventricular echocardiographic parameters and cardiac biomarker levels (N-terminal pro-b-type natriuretic peptide, NT-proBNP; soluble growth stimulation expressed gene 2, ST2; troponin T; and creatine kinase) were assessed at baseline and after the intervention (16 weeks).

Results

Eighty participants (58.4 ± 8.3 yrs, 82.5% male) were included. Both low- and high-volume HIIT showed increases (p < 0.05) in left ventricular end-diastolic diameter (1.2%, 2.6%), and volume (1.1%, 1.3%), respectively. Interventricular septal and posterior walls maintained their thickness (p = 0.36) concerning the AC. Significant (p < 0.05) gain in diastolic function was shown with the improvements in E (-2.1%, -3.3%), e' waves (2.2%, 5.5%), and the deceleration time (2.1%, 2.9%), and in systolic function with a reduction in global longitudinal strain (-3.2%, -4.7%), respectively. Significant (p < 0.05) reductions of N-terminal pro-B-type natriuretic peptide (NT-proBNP) (-4.8%, -11.1%) and of ST2 (-21.7%, -16.7%)were found in both HIIT groups respectively compared to the AC group. Creatine kinase elevation was shown only in high-volume HIIT (19.3%, p < 0.01).

Conclusions

Low-volume HIIT is proposed as a clinically time-efficient and safer strategy to attenuate dysfunctional remodeling by preventing wall thinning and improving LV function in post-MI patients.

Screening for Biomarkers Associated with Left Ventricular Function During Follow-up After Acute Coronary Syndrome

A proportion of patients with the acute coronary syndrome (ACS) will suffer progressive remodeling of the left ventricular (LV). The aim was to screen for important biomarkers from a large-scale protein profiling in 420 ACS patients and define biomarkers associated with reduced LV function early and 1 year after the ACS. Transferrin receptor protein 1 and NT-proBNP were associated with LV function early and after 1 year, whereas osteopontin and soluble ST2 were associated with LV function in the early phase and, tissue-type plasminogen activator after 1 year. Fatty-acid-binding protein and galectin 3 were related to worse GLS but not to LVEF 1 year after the ACS. Proteins involved in remodeling and iron transport in cardiomyocytes were related to worse LV function after ACS. Biomarkers for energy metabolism and fibrosis were exclusively related to worse LV function by GLS. Studies on the functions of these proteins might add knowledge to the biological processes involved in heart failure in long term after ACS.

Evaluation of IL-33R and Galectin-3 as New Biomarkers of Cardiac Damage after Polytrauma-Association with Cardiac Comorbidities and Risk Factors

Polytrauma is one of the disorders with the greatest economic impact on healthcare in society and one predictor for poor outcome is cardiac damage. Interleukin 33 receptors (IL-33R) and galectin-3 are two new potential cardiac trauma biomarkers that are the subjects of this investigation. Additionally, this study assesses pre-existing cardiac damage or risk factors as predictors of cardiac damage after polytrauma. This retrospective study includes 107 polytraumatized patients with an ISS ≥16 admitted in a Level 1 Trauma Centre. Plasma samples were taken at admission. IL-33R and galectin-3 concentrations were detected in plasma samples by ELISA. Both did not correlate with the cardiac damage measured by troponin. Next to troponin, IL-33R was increased in patients with pre-existing cardiac comorbidities. In the subgroup of patients with cardiac comorbidities, the BMI and the initial blood sugar level were significantly increased compared to patients without cardiac comorbidities. Galectin-3 and IL-33R were shown to not correlate with cardiac damage. However, our data suggests that IL-33R protein should be revised in future studies as a marker of cardiac comorbidities. Further, our data indicate that patients with cardiac comorbidities represent a separate group of polytrauma patients characterized by higher concentrations of troponin, IL-33R, BMI and initial sugar level.

Expression of soluble ST2 in patients with essential hypertension and its relationship with left ventricular hypertrophy

AIMS

Identification and intervention of left ventricular hypertrophy (LVH) in essential hypertension (EH) are important for the prevention of adverse cardiovascular events. However, effective methods for diagnosing LVH are still lacking. This study aimed to explore the relationship between soluble ST2 (sST2) and LVH in EH patients to identify a potential specific biomarker for hypertensive LVH.

METHODS AND RESULTS

This study included 97 EH patients. Based on the criteria for LVH, participants were divided into the LVH group (n = 52) and the non-LVH group (n = 45). The level of serum sST2 was detected by enzyme-linked immunosorbent assay. Pearson correlation analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis were used to investigate the potential of sST2 as a biomarker of LVH in EH patients. Compared with the non-LVH group, the sST2 level was elevated in EH patients with LVH (P < 0.001). Pearson correlation analysis indicated that the sST2 level was positively correlated with the left ventricular mass index in EH patients (r = 0.454, P < 0.001). Logistic regression analysis showed that the odds ratio (OR) value of LVH was 2.990, suggesting that sST2 is an independent risk factor for LVH in EH patients [OR = 2.990, 95% confidence interval (CI), 1.650-5.419; P < 0.001]. The area under the ROC curve was 0.767 (95% CI, 0.669-0.866; P < 0.001), with a sensitivity of 0.808 and specificity of 0.689, indicating the possibility of considering sST2 as a biomarker for diagnosing LVH.

CONCLUSIONS

Up-regulation of sST2 is strongly related to LVH in EH patients, is an independent risk factor for hypertensive LVH, and can be used as a biomarker for the diagnosis of LVH.

Effect of β-Blocker Therapy on the Level of Soluble ST2 Protein in Pediatric Dilated Cardiomyopathy

Background and Objectives: A prognosis for kids with pediatric dilated cardiomyopathy (PDCM) is urgently needed to identify high-risk patients. This study aimed to determine the association of levels and soluble suppression of tumorigenicity 2 (sST2) and medical therapy of β-blocker inhibitors with the risk of adverse events in PDCM. Materials and Methods: A total of 124 patients with PDCM were enrolled after admission from 2 centers in China and followed up for adverse events (death, cardiac transplantation, and heart-failure-related rehospitalization). Based on a median sST2 level and the usage of β-blocker inhibitors, patients were divided into four groups. The Cox proportional hazard model was used to assess the risk of incident adverse events. Results: The median level of sST2 was 23.77 ng/mL, and 53 (42.7%) patients received β-blocker treatment. Over a median follow-up of 678 days, 37 (29.8%) adverse events occurred. Compared with patients with sST2 < median and without β-blocker, patients with sST2 ≥ median and without β-blocker (HR: 7.01; 95% CI: 1.21−40.45), followed by those with sST2 ≥ median and use of β-blocker had the highest risk of adverse events (hazard ratio (HR): 5.51; 95% confidence interval (CI): 1.17−25.84). However, a significant association was not observed in patients with sST2 < median and use of β-blocker. These associations were consistent across different subgroups. Conclusions: A higher level of sST2 was associated with a higher risk of adverse events in patients with PDCM, and β-blocker treatment for children with high levels of sST2 can effectively avoid adverse events.

From Classic to Modern Prognostic Biomarkers in Patients with Acute Myocardial Infarction

Despite all the important advances in its diagnosis and treatment, acute myocardial infarction (AMI) is still one of the most prominent causes of morbidity and mortality worldwide. Early identification of patients at high risk of poor outcomes through the measurement of various biomarker concentrations might contribute to more accurate risk stratification and help to guide more individualized therapeutic strategies, thus improving prognoses. The aim of this article is to provide an overview of the role and applications of cardiac biomarkers in risk stratification and prognostic assessment for patients with myocardial infarction. Although there is no ideal biomarker that can provide prognostic information for risk assessment in patients with AMI, the results obtained in recent years are promising. Several novel biomarkers related to the pathophysiological processes found in patients with myocardial infarction, such as inflammation, neurohormonal activation, myocardial stress, myocardial necrosis, cardiac remodeling and vasoactive processes, have been identified; they may bring additional value for AMI prognosis when included in multi-biomarker strategies. Furthermore, the use of artificial intelligence algorithms for risk stratification and prognostic assessment in these patients may have an extremely important role in improving outcomes.

Soluble ST2: a valuable prognostic marker in heart failure

Natriuretic peptides have been at the forefront of biomarker use in heart disease and have been universally recommended as the ideal biomarker in the setting of heart failure. Soluble ST2 is one such biomarker which has found value as a prognostic marker and can be used individually or along with natriuretic peptides in order to prognosticate patients with heart failure. Leading cardiovascular organisations have recognised this biomarker, though its role as a diagnostic marker is yet to be determined. We aim to investigate the role of sST2 in heart failure in the existing literature.

Aptamers Targeting Cardiac Biomarkers as an Analytical Tool for the Diagnostics of Cardiovascular Diseases: A Review

The detection of cardiac biomarkers is used for diagnostics, prognostics, and the risk assessment of cardiovascular diseases. The analysis of cardiac biomarkers is routinely performed with high-sensitivity immunological assays. Aptamers offer an attractive alternative to antibodies for analytical applications but, to date, are not widely practically implemented in diagnostics and medicinal research. This review summarizes the information on the most common cardiac biomarkers and the current state of aptamer research regarding these biomarkers. Aptamers as an analytical tool are well established for troponin I, troponin T, myoglobin, and C-reactive protein. For the rest of the considered cardiac biomarkers, the isolation of novel aptamers or more detailed characterization of the known aptamers are required. More attention should be addressed to the development of dual-aptamer sandwich detection assays and to the studies of aptamer sensing in alternative biological fluids. The universalization of aptamer-based biomarker detection platforms and the integration of aptamer-based sensing to clinical studies are demanded for the practical implementation of aptamers to routine diagnostics. Nevertheless, the wide usage of aptamers for the diagnostics of cardiovascular diseases is promising for the future, with respect to both point-of-care and laboratory testing.

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.

Serum CD40L, ST2, IL-6, and CRP serving as biomarkers for acute coronary syndrome

To analyze the diagnostic value of CD40 ligand (CD40L), soluble growth stimulating expression gene 2 protein (ST2), interleukin-6 (IL-6), and C-reactive protein (CRP) are used in patients with acute coronary syndrome (ACS). Serum samples were collected from 259 ACS patients admitted to our hospital. Additionally, 119 healthy individuals who received physical examination in the hospital at the same time period were included as normal control. The levels of CD40L, ST2, IL-6, and CRP in 259 patients with ACS and 119 healthy subjects were detected by ELISA. The levels of CD40L, ST2, IL-6, and CRP were significantly increased in unstable angina (UA) patients, while ST2, CRP, and IL-6 were significantly elevated in acute myocardial infarction (AMI) patients. Pearson correlation analysis showed that ST2 was also closely related to CRP in ACS patients, while ST2 was positively correlated with creatine kinase (CK), creatine kinase isoenzyme (CK-MB), and troponin I (cTnI) in AMI patients. The levels of glucose (GLU) and low-density lipoprotein cholesterol (LDL-c) were significantly decreased, while the levels of high-density lipoprotein cholesterol (HDL-c) were significantly increased in AMI patients treated with stent implantation. Furthermore, the level of serum CD40 L was significantly elevated in coronary heart disease (CHD) patients treated with stent implantation, while the levels of ST2 and IL-6 in AMI patients treated with the stent implantation decreased significantly. The levels of inflammatory factors significantly changed in patients with ACS. These inflammatory factors may involve in the pathological progression of ACS and can be used as diagnostic indexes for ACS.

Soluble ST2 as a Potential Biomarker for Risk Assessment of Pulmonary Hypertension in Patients Undergoing TAVR?

Background: Severe aortic valve stenosis (AS) is associated with pulmonary hypertension (PH) and has been shown to limit patient survival. Soluble suppression of tumorigenicity-2 (sST2) is a cardiovascular biomarker that has proven to be an important prognostic marker for survival in patients undergoing transcatheter aortic valve replacement (TAVR). The aim of this study was to assess the importance of the sST2 biomarker for risk stratification in patients with severe AS in presence or absence of PH. Methods: In 260 patients with severe AS undergoing TAVR procedure, sST2 serum level concentrations were analyzed. Right heart catheter measurements were performed in 152 patients, with no PH detection in 43 patients and with PH detection in 109 patients. Correlation analyses according to Spearman, AUROC analyses and Kaplan–Meier curves were calculated. Results: Patients with severe AS and PH showed significantly higher serum sST2 concentrations (p = 0.006). The sST2 cut-off value for non-PH patients regarding 1-year survival yielded 5521.15 pg/mL, whereas the cut-off value of PH patients was at a considerably higher level of 10,268.78 pg/mL. A cut-off value of 6990.12 pg/mL was related with a significant probability of PH presence. Survival curves showed that patients with severe AS and PH not only had higher 1-year mortality, but also that increased levels of sST2 plasma concentration were associated with earlier death. Conclusion: sST2 definitely has the potential to provide information about the presence of PH in patients with severe AS, in a noninvasive way.

Correlation between Serum LP-PLA2 and sST2 Levels and the Condition of Patients with Acute Heart Failure and Their Prognostic Value

Acute heart failure (AHF) occurs mostly in the elderly, which is a syndrome that occurs in the later stages of the development of cardiovascular disease. Due to the sharp decline in the patient's heart function, the patient has a high mortality rate and a poor prognosis, which seriously threaten the life safety of the elderly. Therefore, early diagnosis of AHF and timely treatment are extremely important. Lipoprotein-associated phospholipase A2 (LP-PLA2) is a newly discovered cardiovascular-specific inflammatory marker, which is closely related to the formation and progression of atherosclerotic plaque and the occurrence and development of coronary heart disease. Soluble growth stimulation expression gene 2 (sST2) protein is a protein produced under the induction of mechanical stress in cardiomyocytes. It can act as a decoy receptor to mediate the interleukin-33 (IL-33)/ST2 signaling pathway to bind to IL-33, thereby reducing the myocardial protective effect and leading to myocardial remodeling. The purpose of this study was to explore the serum LP-PLA2 and sST2 levels in AHF patients and to analyze their correlation with the disease and their prognostic value. The results showed that the levels of serum LP-PLA2 and sST2 were increased in AHF patients, and the levels of serum LP-PLA2 and sST2 in patients with adverse prognostic events were higher than those in patients without adverse prognostic events. The levels of serum LP-PLA2 and sST2 are closely related to the degree of patients' illness, among which the combined prediction of AHF patients with LP-PLA2 and sST2 has the highest value, which is worthy of promotion.

A Novel Paradigm Based on ST2 and Its Contribution towards a Multimarker Approach in the Diagnosis and Prognosis of Heart Failure: A Prospective Study during the Pandemic Storm

Background: Acute heart failure (HF) represents an increasingly common and challenging presentation in the emergency room, also inducing a great socio-economic burden. Extensive research was conducted toward finding an ideal biomarker of acute HF, both in terms of sensitivity and specificity, but today practicians’ interest has shifted towards a more realistic multimarker approach. Natriuretic peptides (NPs) currently represent the gold standard for diagnosing HF in routine clinical practice, but novel molecules, such as sST2, emerge as potentially useful biomarkers, providing additional diagnostic and prognostic value. Methods: We conducted a prospective, single-center study that included 120 patients with acute HF and 53 controls with chronic HF. Of these, 13 patients (eight with acute HF, five from the control group) associated the coronavirus-19 disease (COVID-19). The diagnosis of HF was confirmed by a complete clinical, biological and echocardiographic approach. Results: The serum levels of all studied biomarkers (sST2, NT-proBNP, cardiac troponin) were significantly higher in the group with acute HF. By area under the curve (AUC) analysis, we noticed that NT-proBNP (AUC: 0.976) still had the best diagnostic performance, closely followed by sST2 (AUC: 0.889). However, sST2 was a significantly better predictor of fatal events, showing positive correlations for both in-hospital and at 1-month mortality rates. Moreover, sST2 was also associated with other markers of poor prognosis, such as the use of inotropes or high lactate levels, but not with left ventricle ejection fraction, age, body mass index or mean arterial pressure. sST2 levels were higher in patients with a positive history of COVID-19 as compared with non-COVID-19 patients, but the differences were statistically significant only within the control group. Bivariate regression showed a positive and linear relationship between NT-proBNP and sST2 (r(120) = 0.20, p < 0.002). Conclusions: we consider that sST2 has certain qualities worth integrating in a future multimarker test kit alongside traditional biomarkers, as it provides similar diagnostic value as NT-proBNP, but is emerging as a more valuable prognostic factor, with a better predictive value of fatal events in patients with acute HF.

Biomarkers in the management of acute heart failure: state of the art and role in COVID-19 era

Acute heart failure (AHF) affects millions of people worldwide, and it is a potentially life‐threatening condition for which the cardiologist is more often brought into play. It is crucial to rapidly identify, among patients presenting with dyspnoea, those with AHF and to accurately stratify their risk, in order to define the appropriate setting of care, especially nowadays due to the coronavirus disease 2019 (COVID‐19) outbreak. Furthermore, with physical examination being limited by personal protective equipment, the use of new alternative diagnostic and prognostic tools could be of extreme importance. In this regard, usage of biomarkers, especially when combined (a multimarker approach) is beneficial for establishment of an accurate diagnosis, risk stratification and post‐discharge monitoring. This review highlights the use of both traditional biomarkers such as natriuretic peptides (NP) and troponin, and emerging biomarkers such as soluble suppression of tumourigenicity (sST2) and galectin‐3 (Gal‐3), from patients' emergency admission to discharge and follow‐up, to improve risk stratification and outcomes in terms of mortality and rehospitalization.

Status of biomarkers for the identification of stable or vulnerable plaques in atherosclerosis

Atherosclerosis is a systemic inflammation of the arteries characterized by atherosclerotic plaque due to the accumulation of lipids, inflammatory cells, apoptotic cells, calcium and extracellular matrix (ECM) proteins. Stable plaques present a chronic inflammatory infiltration, whereas vulnerable plaques present an 'active' inflammation involved in the thinning of the fibrous cap that predisposes to plaque rupture. Several complex biological cellular processes lead plaques to evolve from stable to vulnerable predisposing them to rupture and thrombosis. In this review, we analyze some emerging circulating biomarkers related to inflammation, ECM and lipid infiltration, angiogenesis, metalloproteinases and microRNA (miRNA), as possible diagnostic and prognostic indicators of plaque vulnerability.

The Role of Galectin-3 and ST2 in Cardiology: A Short Review

Galectin-3 is a lectin that binds beta-galactosides. It is involved in cardiac remodeling and fibrosis through the activation of macrophages and fibroblasts. ST2 is secreted by myocardial cells due to cardiac overload. These two biomarkers have been traditionally studied in the field of heart failure to guide medical therapy and detect the progression of the disease. Nevertheless, there are novel evidences that connect galectin-3 and ST2 with coronary heart disease and, specifically, with atrial fibrillation. The aim of this article is to concisely review the diagnostic and prognostic role of galectin-3 and ST2 in different cardiac diseases.

Ability of soluble ST2 to predict left ventricular remodeling in patients with acute coronary syndrome

The association of the soluble suppression of tumorigenicity 2 (sST2) and the prognosis of heart failure have been well evaluated. However, little is known about the prediction of sST2 for left ventricular (LV) remodeling in acute coronary syndrome (ACS). We investigated the ability of sST2 to predict LV remodeling following the revascularization of ACS. From May 2019 to December 2020, 95 patients with LV ejection fraction (EF) < 50% who underwent coronary revascularization for ACS (unstable angina, non-ST-elevation myocardial infarction, ST-elevation myocardial infarction) were enrolled. Echocardiography and sST2 were performed at baseline and at a 3-month follow-up. The association between LV remodeling, using the end-diastolic volume index, and sST2 at baseline and at the 3-month follow-up, and the difference between each value was explored. During follow-up, 41 patients showed LV adverse remodeling. The baseline sST2 increased in patients without adverse remodeling (32.05 ng/mL vs. 23.5 ng/mL, p < 0.001), although clinical characteristics were similar between the two groups. During the mean follow-up of 3 months, a significant correlation was found in the changes between sST2 and LV end-diastolic/systolic volume index (r = 0.649; p < 0.001, r = 0.618; p < 0.001, respectively), but not in the changes of LVEF (r = - 0.132, p = 0.204). The use of angiotensin-converting enzyme 2 inhibitors/receptor blockers was higher (90.7% vs. 53.7%, p < 0.001) and sST2 decreased more predominantly in patients without adverse remodeling (23.18 ng/mL vs 26.40 ng/mL, p = 0.003). However, the changes in sST2 and LV volume were not different according to the ACS types (p > 0.05, for all). Estimates of the odds ratio (OR) for remodeling according to the sST2 difference increased substantially with a negative increase in the sST2 difference. Multivariable analysis found that, the difference between the baseline and 3-month sST2 was the most important determinant of LV remodeling following the revascularization of ACS (OR 1.24; 95% confidence interval: 1.09 to 1.41; p = 0.001). In conclusion, an increase in sST2 during follow-up was a useful predictor of LV remodeling.

Traditional and Emerging Biomarkers in Asymptomatic Left Ventricular Dysfunction-Promising Non-Coding RNAs and Exosomes as Biomarkers in Early Phases of Cardiac Damage

Heart failure (HF) is one of the major causes of morbidity and mortality worldwide and represents an escalating problem for healthcare systems. The identification of asymptomatic patients with underlying cardiac subclinical disease would create an opportunity for early intervention and prevention of symptomatic HF. Traditional biomarkers are very useful as diagnostic and prognostic tools in the cardiovascular field; however, their application is usually limited to overt cardiac disease. On the other hand, a growing number of studies is investigating the diagnostic and prognostic potential of new biomarkers, such as micro-RNAs (miRNA), long non-coding RNAs, and exosome cargo, because of their involvement in the early phases of cardiac dysfunction. Unfortunately, their use in asymptomatic phases remains a distant goal. The aim of this review is to gather the current knowledge of old and novel biomarkers in the early diagnosis of cardiac dysfunction in asymptomatic individuals.

Prognostic value of soluble suppression of tumorigenesis-2 (sST2) for cardiovascular events in coronary artery disease patients with and without diabetes mellitus

Background

Soluble suppression of tumorigenesis-2 (sST2) is implicated in myocardial overload and has long been recognized as an inflammatory marker related to heart failure and acute coronary syndrome, but data on the prognostic value of sST2 in patients with coronary artery disease (CAD) remain limited. This study sought to investigate the prognostic value of sST2 in patients with established CAD and its predictive value in CAD patients with and without type 2 diabetes mellitus (T2DM).

Methods

A total of 3641 consecutive patients were included in this prospective cohort study. The primary end point was major adverse cardiovascular events (MACEs). The secondary end point was all-cause death. The association between sST2 and outcomes was investigated using multivariable Cox regression.

Results

During a median follow-up of 6.4 years, MACEs occurred in 775 patients, and 275 patients died. Multiple Cox regression models showed that a higher level of sST2 was an independent predictor of MACEs development (HR = 1.36, 95% CI 1.17–1.56, p < 0.001) and all-cause death (HR = 2.01, 95% CI 1.56–2.59, p < 0.001). The addition of sST2 to established risk factors significantly improved risk prediction of the composite outcome of MACEs and all-cause death (C-index, net reclassification index, and integrated discrimination improvement, all p < 0.05). In subgroup analysis depending on diabetes status, the diabetes group had a significantly higher level of sST2, which remained a significant predictor of MACEs and all-cause death in patients with and without T2DM in multivariable models. The area under the curve (AUC) of CAD patients with diabetes mellitus was significantly higher than that of those without T2DM. For MACEs, the AUC was 0.737 (patients with T2DM) vs 0.620 (patients without T2DM). For all-cause death, the AUC was 0.923 (patients with T2DM) vs 0.789 (patients without T2DM).

Conclusions

A higher level of sST2 is significantly associated with long-term MACEs and all-cause death in CAD patients with and without T2DM. sST2 has strong predictive value for cardiovascular adverse events in CAD patients with T2DM, and these results provide new evidence for the role of sST2.

The Novel Perspectives Opened by ST2 in the Pandemic: A Review of Its Role in the Diagnosis and Prognosis of Patients with Heart Failure and COVID-19

The increasing incidence of coronavirus disease 19 (COVID-19) and its polymorphic clinical manifestations due to local and systemic inflammation represent a high burden for many public health systems. Multiple evidence revealed the interdependence between the presence of cardiovascular comorbidities and a severe course of COVID-19, with heart failure (HF) being incriminated as an independent predictor of mortality. Suppression of tumorigenicity-2 ST2 has emerged as one of the most promising biomarkers in assessing the evolution and prognosis of patients with HF. The uniqueness of ST2 is determined by its structural particularities. Its transmembrane isoform exerts cardioprotective effects, while the soluble isoform (sST2), which is detectable in serum, is associated with myocardial fibrosis and poor outcome in patients with HF. Some recent data also suggested the potential role of sST2 as a marker of inflammation, while other studies highlighted it as a valuable prognostic factor in patients with COVID-19. In this review, we summarized the pathways by which sST2 is related to myocardial injury and its connection to the severity of inflammation in patients with COVID-19. Also, we reviewed possible perspectives of using it as a dual cardio-inflammatory biomarker, for both early diagnosis, risk stratification and prognosis assessment of patients with concomitant HF and COVID-19.

A combination of NLR and sST2 is associated with adverse cardiovascular events in patients with myocardial injury induced by moderate to severe acute carbon monoxide poisoning

Background

Indicators of adverse cardiovascular events in patients with acute carbon monoxide (CO) poisoning‐induced myocardial injury have not yet been elucidated.

Hypothesis

This study aimed at determining the risk factors for adverse cardiovascular events in patients with acute CO poisoning‐induced myocardial injury.

Methods

We enrolled patients with moderate‐to‐severe acute CO poisoning‐induced myocardial injury. Based on the occurrence of adverse cardiovascular events, the patients were assigned into event and non‐event group. Binary logistic regression analysis was performed to analyze the potential risk factors for cardiovascular adverse events.

Results

A total of 413 eligible patients were enrolled. Among them, 61 (14.8%) patients presented adverse cardiovascular events and were assigned to the event group while 352 patients were assigned to the non‐event group. Univariate analysis revealed that cTnI, Lac, and NLR levels at admission and sST2 at day 3 in the event group were significantly higher compared to those in the non‐event group. Subsequent multivariate analysis revealed that sST2 at day 3 and NLR at admission were independent risk factors for adverse cardiovascular events in patients with acute CO poisoning‐induced myocardial injury. Finally, the sensitivity, specificity, and AUC of sST2 at day 3 combined with NLR for event prediction were 79.5%, 82.8%, and 0.858, respectively.

Conclusion

A combination of sST2 at day 3 and NLR is a potential predictor for the occurrence of adverse cardiovascular events in patients with acute CO poisoning‐induced myocardial injury. Therefore, cardiovascular risk stratification should be taken into consideration, especially in patients with acute CO poisoning‐induced myocardial injury.

A review of biosensor technologies for blood biomarkers toward monitoring cardiovascular diseases at the point-of-care

Cardiovascular diseases (CVDs) cause significant mortality globally. Notably, CVDs disproportionately negatively impact underserved populations, such as those that are economically disadvantaged and often located in remote regions. Devices to measure cardiac biomarkers have traditionally been focused on large instruments in a central laboratory but the development of affordable, portable devices that measure multiple cardiac biomarkers at the point-of-care (POC) are needed to improve clinical outcomes for patients, especially in underserved populations. Considering the enormity of the global CVD problem, complexity of CVDs, and the large candidate pool of biomarkers, it is of great interest to evaluate and compare biomarker performance and identify potential multiplexed panels that can be used in combination with affordable and robust biosensors at the POC toward improved patient care. This review focuses on describing the known and emerging CVD biosensing technologies for analysis of cardiac biomarkers from blood. Initially, the global burden of CVDs and the standard of care for the primary CVD categories, namely heart failure (HF) and acute coronary syndrome (ACS) including myocardial infarction (MI) are discussed. The latest United States, Canadian and European society guidelines recommended standalone, emerging, and add-on cardiac biomarkers, as well as their combinations are then described for the prognosis, diagnosis, and risk stratification of CVDs. Finally, both commercial in vitro biosensing devices and recent state-of-art techniques for detection of cardiac biomarkers are reviewed that leverage single and multiplexed panels of cardiac biomarkers with a view toward affordable, compact devices with excellent performance for POC diagnosis and monitoring.

Circulating Soluble ST2 Predicts All-Cause Mortality in Severe Heart Failure Patients with an Implantable Cardioverter Defibrillator

Background

Heart failure (HF) is the terminal stage of all cardiovascular events. Although implantable cardioverter defibrillator (ICD) therapies have reduced mortality among the high-risk HF population, it is necessary to determine whether certain factors can predict mortality even after cardiac device implantation. Growth stimulation expressed gene 2 (ST2) is an emerging biomarker for HF patient stratification in different clinical settings.

Aims

This study aimed to investigate the relationship between baseline soluble ST2 (sST2) levels in serum and the clinical outcomes of high-risk HF patients with device implantation.

Methods

Between January 2017 and August 2018, we prospectively recruited consecutive patients implanted with an ICD for heart failure, with LVEF ≤35% as recommended, and analyzed the basic characteristics, baseline serum sST2, and NT-proBNP levels, with at least 1-year follow-up. All-cause mortality was the primary endpoint.

Results

During a 643-day follow-up, all-cause mortality occurred in 16 of 150 patients (10.67%). Incidence of all-cause mortality increased significantly in patients with sST2 levels above 34.98846 ng/ml (16.00% vs. 5.33%, P = 0.034). After adjusting the model (age, gender, device implantation, prevention of sudden death, LVEDD, LVEF, WBC and CLBBB, hsTNT, etiology, and eGFR) and the model combined with NT-proBNP, the risk of all-cause death was increased by 2.5% and 1.9%, respectively, per ng/ml of sST2. The best sST2 cutoff for predicting all-cause death was 43.42671 ng/ml (area under the curve: 0.72, sensitive: 0.69, and specificity: 0.69). Compared to patients with sST2 levels below 43.42671 ng/ml, the risk of all-cause mortality was higher in those with values above the threshold (5.1% vs. 21.2%, P = 0.002). ST2 level ≥43.42671 ng/ml was an independent predictor of all-cause mortality (HR: 3.30 [95% CI 1.02–10.67]). Age (HR: 1.06 [95% CI: 1.01–1.12]) and increased NT-proBNP per 100 (HR: 1.02 [95% CI: 1.01–1.03]) were also associated with all-cause mortality in ICD patients.

Conclusions

sST2 level was associated with risk of all-cause mortality, and a threshold of 43.43 ng/ml showed good distinguishing performance to predict all-cause mortality in patients with severe heart failure, recommended for ICD implantation. Patients with sST2 levels more than 43.42671 ng/ml even after ICD implantation should therefore be monitored carefully.

An impedimetric biosensor system based on disposable graphite paper electrodes: Detection of ST2 as a potential biomarker for cardiovascular disease in human serum

In present study, we developed a highly sensitive, electrochemical immunosensor based on fullerene C₆₀-modified disposable graphite paper (GP) electrode for determination of Suppression of Tumorigenicity 2 (ST2) in human serum. The synthesis of the ST2 immunosensor was monitored with electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) techniques and single frequency impedance (SFI) technique which is utilized for the specific interaction between anti-ST2 and ST2 antigen. Moreover, the morphological alteration of each GP surface was examined by scanning electron microscopy (SEM), SEM-energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM). All parameters such as fullerene C₆₀ concentration, antibody concentration and antibody incubation time were optimized. Analytical characteristics such as linear determination range, repeatability, reproducibility, regeneration and surface coverage were determined for the immunosensor. The ST2 electrochemical immunosensor had excellent repeatability, reproducibility and a wide detection range (from 0.1 fg mL^-1 to 100 fg mL^-1). The proposed immunosensor also had low limit of detection (LOD) and limit of quantification (LOQ) values of 0.124 fg mL^-1 and 0.414 fg mL^-1, respectively. The proposed immunosensor was applied to real samples to test applicability in clinical practice.

Suppression tumorigenicity 2 (ST2) turbidimetric immunoassay compared to enzyme-linked immunosorbent assay in predicting survival in heart failure patients with reduced ejection fraction

BACKGROUND

Suppressor of tumorigenicity 2 (ST2) is a powerful marker of prognosis and treatment response in heart failure (HF), however, it is an enzyme-linked immunosorbent assay (ELISA) which may be cumbersome and costly. A turbidimetric immunoassay (TIA) that can run on common chemistry analyzers could overcome this. We studied a novel TIA for ST2, comparing it to commercial ST2 (ELISA).

METHODS

Patients age ≥ 18 years meeting Framingham definition for HF were enrolled in a prospective registry (Oct 2007 - March 2015) at Henry Ford Hospital and donated blood samples. Participants with reduced ejection fraction (<50%) and available plasma samples were included and valid ST2 measurements were obtained on the same sample using both TIA and ELISA (N = 721). The primary endpoint was all cause death. Correlation between the methods was quantified. The association with survival was tested using unadjusted and adjusted (for MAGGIC score and NTproBNP) Cox models and comparing the Area Under the Curve (AUC).

RESULTS

The inter-assay Spearman correlation coefficient was 0.77. Nonparametric regression showed no significant proportional difference (slope = 0.97) and a very small systematic difference (3.2 ng/mL). In univariate analyses, both TIA and ELISA ST2 were significant associates of survival with similar effect sizes (HR 4.46 and 3.50, respectively, both p < 0.001). In models adjusted for MAGGIC score, both ST2 remained significant in Cox models and incrementally improved AUC vs. MAGGIC alone (MAGGIC AUC = 0.757; TIA + MAGGIC AUC = 0.786, p = 0.025; ELISA + MAGGIC AUC = 0.793, p = 0.033). In models with both MAGGIC and NTproBNP included, both ST2 still remained significant but did not improve AUC.

CONCLUSIONS

A novel TIA method for ST2 quantification correlates highly with ELISA and offers similarly powerful risk-stratification.

Biomarkers of IL-33 and sST2 and Lack of Association with Carvedilol Therapy in Heart Failure

OBJECTIVE

The IL-33/ST2 pathway plays a fundamental role in the cardiovascular system and can be considered as a new therapeutic strategy for the treatment or prevention of cardiovascular diseases. ST2, as an interleukin (IL)-1 receptor family member, has transmembrane (ST2L) and soluble (sST2) isoforms. sST2 neutralizes IL-33 and thereby inhibits the cardioprotective role of IL-33/ST2L signaling pathway. Increase in sST2 level is associated with weak cardiac output and can be a predictor of mortality in heart failure (HF). Thereby, we hypothesized that there may be a relationship between the cardioprotective effects of carvedilol and sST2 and IL-3 in HF patients.

METHODS

sST2 and IL-33 were measured in serum of 66 individuals; 22 healthy volunteers and 44 suffering from HF; among whom 25 patients received carvedilol and the other 19 patients did not receive any β-blockers.

RESULTS

Lack of association between serum levels of IL-33 and sST2 was observed between HF patients and healthy individuals (2.4466 ± 0.69 vs 2.6748 ± 0.33 and 3416.6 ± 1089.1 vs 2971.6 ± 792.5, respectively). Our results indicated no significant difference between sST2 and IL-33 levels in HF patients who did not receive beta-blockers and patients receiving carvedilol (P=0.59 and P=0.97).

CONCLUSION

Our results showed a lack of association between serum levels of IL-33 and sST2 and HF. Moreover, the results do not confirm the cardioprotective mechanism of carvedilol by means of IL-33/sST2 pathway.

Multiplex Analysis of Circulating Maternal Cardiovascular Biomarkers Comparing Preeclampsia Subtypes

Preeclampsia, a hypertensive pregnancy disorder, links to increased long-term maternal cardiovascular disease (CVD). The risk is further increased with early-onset preeclampsia (EPE) and delivery of a growth-restricted child. We hypothesized that circulating biomarkers associated with CVD risk differed between preeclampsia subtypes and controls. We compared EPE; n=37, delivery <week 34, late-onset preeclampsia (LPE); n=29, delivery ≥week 34, and normotensive controls (n=49) using Olink Proseek multiplex CVD I assay (targeting 92 biomarkers). We stratified analysis to uteroplacental spiral artery acute atherosis presence in preeclampsia patients, sharing morphological similarities with atherosclerosis. We found 47 CVD-related biomarkers differing between the groups, 42 markers between normotensive controls and EPE, 28 markers between normotensive controls and LPE, and 9 markers between EPE and LPE. Among these 9 markers, ST2 (ST2 protein), MMP (matrix metalloproteinase) 1, MMP3, and fractalkine (CX3CL1) were uniquely dysregulated in EPE. Principal component (PC) analysis of the differing markers identified 4 clusters (named PC1-PC4) that largely separated the preeclampsia and control groups as well as pregnancies with low and high circulating PlGF (placental growth factor). The combination of the single markers PlGF, ST2, MMP1, MMP3, and CX3CL1 had a high discriminatory property to differentiate between EPE and LPE. Preeclampsia with acute atherosis or with fetal growth restriction could be differentiated by Olink biomarkers as compared with preeclampsia without these features. We identified specific CVD-related biomarkers in pregnancy depending on preeclampsia subtypes and uteroplacental acute atherosis. Assessment of these pregnancy measured biomarkers' relation to long-term cardiovascular dysfunction and hard end points is warranted.

A MULTI-MARKER MODEL FOR PREDICTING DECOMPENSATED HEART FAILURE IN PATIENTS WITH PRIOR ACUTE MYOCARDIAL INFARCTION

The aim of the study was to assess the prognostic value of determining the plasma concentration of NT-proBNP and ST2 in the patients with decompensated HF and prior acute myocardial infarction and their combination in this category of patients. Materials and methods. There were examined 120 patients with acute myocardial infarction and stage II A-B decompensated chronic HF according to the classification proposed by Vasylenko V. Kh. and Strazhesko M.D., NYHA functional class (FC) III-IV. The patients with Q-QS wave MI (60 individuals) and non Q MI (60 individuals) were divided into 4 groups depending on the treatment methods. Study groups were homogenous by age, gender, disease severity, duration of the post-infarction period, clinical signs of decompensation, which served as a basis for inclusion of the patients in the study. All the patients underwent the six-minute walk test in a quiet 30-50-m long hospital corridor in the morning. N-terminal pro-B-type brain natriuretic peptide (NT-proBNP) and ST-2 were analyzed in all patients. Results. Promising biomarkers of HF decompensation in the post-infarction period were studied. In the patients with prior Q-QS MI and decompensated HF, NT-proBNP level was (950.38±3.15) pmol/l (p<0.05); in the patients with prior MI without signs of decompensated HF, it was (580.15±3.03) pmol/l (p˂0.05); in apparently healthy individuals, the level of NT-proBNP was found to be (111.20±3.47) pmol/l. ST2 level was (14.80±1.61) ng/ml, (36.00±1.43) ng/ml and (49.22±1.40) ng/ml in the patients of Group 1, Group 2 and Group 3, respectively (p˂0.05). Similar changes were found in patients with decompensated HF in postinfarction period after non Q MI. Conclusions. The increase in plasma concentration of sST2 is associated with the activation of both neurohumoral and fibrous pathways and can help in detecting the patients with decompensated HF in the post-infarction period and predicting the risk of its development. Our results confirmed the results of other multiple studies reporting ST2 in combination with NT-proBNP to be valuable tools for prognosing the development of decompensated HF in the patients with prior MI. ST2, alongside with NT-proBNP, is a promising biomarker to be included in the diagnostic panel for detecting acute HF and can provide additional information on risk stratification for such patients during hospitalization and at the time of discharge from the hospital.