Prognostic Value of Soluble Suppression of Tumorigenicity-2 in Chronic Heart Failure

Fluorescence Aptasensor for sST2 Detection Using In Vitro Selected Aptamers

Soluble suppression of tumorigenicity 2 (sST2) is a critical biomarker for heart failure (HF) diagnosis and prognosis, yet conventional antibody-based detection methods suffer from time-consuming protocols and high costs and involve complex detection procedures. To address these challenges, we first screened high-affinity aptamers under clinically relevant conditions and then coupled with the CRISPR/Cas12a system to develop a fluorescence aptasensor for rapid and sensitive sST2 detection. A serum matrix was introduced during aptamer selection to enhance specificity and anti-interference performance in real biological environments. Three sST2-specific aptamers (Apt-1, Apt-2, and Apt-3) were identified with dissociation constants (KD) of 8.42, 46.08, and 25.02 nM, respectively. Among these, Apt-1 demonstrated superior performance, which was utilized to construct a fluorescence biosensor combining aptamer recognition with CRISPR/Cas12a trans-cleavage signal amplification. The sensor achieved a broad linear detection range (5-120 ng/mL) and an ultralow limit of detection (LOD, 0.816 ng/mL) when applied in detecting sST2 in both the buffer and human serum. Notably, the platform exhibited exceptional resistance to interference from HF-related proteins and maintained high accuracy in clinical serum samples, showing a strong correlation (R2 = 0.9794) with enzyme-linked immunosorbent assay (ELISA) results. By integration of serum-matrix screening and CRISPR-based signal enhancement, this work establishes a robust, cost-effective, and rapid diagnostic tool for sST2 detection.

Biomarkers for Congestion in Heart Failure: State-of-the-art and Future Directions

Congestion in patients with heart failure (HF) predicts adverse outcomes and is a leading cause of hospitalisation. Understanding congestion mechanisms helps in HF management and underscores the importance of tailored therapies to treat vascular and tissue congestion, improving patient outcomes. In this setting, several tools are available to detect congestion. Biomarker measurement is a simple, valid and affordable method to evaluate congestion in patients with HF. Natriuretic peptides are the most widely available tool in acute and chronic HF, helping diagnosis, risk stratification and management. Novel biomarkers can potentially become reliable allies in diagnosing and monitoring patients with HF. This review aims to assess the current scientific literature on biomarkers for managing HF, evaluate their clinical utility and explore future perspectives in this field.

IL-33/ST2 axis in diverse diseases: regulatory mechanisms and therapeutic potential

Interleukin-33 (IL-33) is a nuclear factor and member of the IL-1 cytokine family. IL-33 is mainly expressed by epithelial and endothelial cells and exerts its function through interaction with various immune cells, and binding to its receptor can form the IL-33/Suppression of tumorigenicity 2 (ST2) signaling pathway. While most cytokines are actively synthesized within cells, IL-33 is produced passively in response to tissue damage or cell necrosis, indicating its role as a signaling molecule following cellular infection, stress, or trauma. IL-33/ST2 signaling pathway has been proved to play diverse role in the pathological process of central nervous system disorders, cancer, fibrosis, autoimmune diseases, etc. Although research on the IL-33/ST2 signaling pathway has deepened recently, relevant treatment strategies have been proposed, and even targeted drugs are in the preclinical stage; further research on the effect of the IL-33/ST2 signaling pathway in different diseases is still necessary, to provide a clearer understanding of the different roles of IL-33/ST2 in disease progression and to develop new drugs and treatment strategies. Because IL-33/ST2 plays an important role in the occurrence and progression of diseases, the study of therapeutic drugs targeting this pathway is also necessary. This review focused on recent studies on the positive or negative role of IL-33/ST2 in different diseases, as well as the current related drugs targeting IL-33/ST2 in the preclinical and clinical stage. The mechanism of IL-33/ST2 in different diseases and its mediating effect on different immune cells have been summarized, as well as the antibody drugs targeting IL-33 or ST2, natural compounds with a mediating effect, and small molecule substances targeting relative pathway. We aim to provide new ideas and treatment strategies for IL-33/ST2-related drugs to treat different diseases.

Examining the Long-Term Prognostic Significance of Serum sST2: Influence of Myocardial Infarction History and Subgroup Level Standardization

Aim

In this study, the predictive value of soluble growth stimulation expressed gene 2 protein (sST2) for long-term clinical outcomes in patients with acute heart failure (AHF) is assessed. In addition, the influence of a history of myocardial infarction on the levels of sST2 in patients with HF, as well as its impact on outcome events, is explored. We also aim to establish a specific standard for sST2 levels in this subgroup.

Methods

We conducted an ambispective cohort study involving hospitalized patients with AHF, measuring their sST2 levels and following their progress over three years. The primary endpoint was major adverse cardiovascular events (MACEs), encompassing heart failure readmission and all-cause mortality over three years. Cox regression analysis was used to evaluate the prognostic significance of sST2 levels, along with a subgroup analysis using propensity score matching (PSM) to adjust for confounding variables. Receiver operating characteristic (ROC) curve analysis was utilized to determine the optimal sST2 threshold using Youden's J statistics, and a sensitivity analysis included Kaplan-Meier survival curves.

Results

The study included 149 patients with a median age of 68 years, of whom 57% were male. Both univariate and multivariate Cox regression analyses confirmed sST2 as an independent predictor of MACEs. Post-PSM analysis, 124 samples were grouped by MI history ROC curve analysis revealed an area under the curve of 0.726 for predicting MACEs in patients with MI, demonstrating a significant predictive value for sST2 levels above 34 ng/mL, which correlated with increased readmission and mortality rates. In contrast, sST2 levels in patients without MI history showed no significant predictive relevance.

Conclusion

sST2 has significant long-term predictive value for clinical outcomes in patients with AHF, particularly for those with a prior MI history, indicating a need for heightened clinical attention and thorough follow-up to mitigate long-term adverse cardiovascular outcomes.

Association of soluble suppression of tumorigenicity 2 with mortality and adverse outcomes in chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

Early risk stratification is necessary to prevent chronic kidney disease progression and complications. This systematic review aims to evaluate the association of soluble suppression of tumorigenicity 2 (sST2), a member of the interleukin-1 receptor family, with all-cause mortality, cardiovascular disease and renal function deterioration among chronic kidney disease patients.

METHODS

PubMed, Scopus, Web of Science, CENTRAL and Google Scholar were systematically searched from inception to December 20, 2023. Cohort studies examining the prognostic role of sST2 levels in pre-dialysis and dialysis patients were included. In case of 3 or more studies per outcome, conventional and dose-response meta-analyses were conducted.

RESULTS

Overall, 21 studies were included comprising 15,100 patients. In pre-dialysis patients, the qualitative synthesis of studies suggested that high sST2 is associated with significantly increased all-cause mortality, while evidence regarding cardiovascular events or kidney disease progression was conflicting. In the dialysis population, high sST2 was linked to an elevated risk of all-cause (Hazard ratio-HR: 3.00, 95% confidence intervals-CI: 1.95-4.61) and cardiovascular (HR: 2.38, 95% CI: 1.69-3.34) mortality. Dose-response meta-analysis suggested a log-linear association of sST2 with both all-cause (χ2: 34.65, p value < 0.001) and cardiovascular (χ2: 29.14, p value < 0.001) mortality, whereas findings regarding cardiovascular events were limited with mixed results.

CONCLUSIONS

High sST2 values are associated with an increased risk of all-cause mortality in pre-dialysis and dialysis patients, as well as with an elevated risk of cardiovascular mortality in the dialysis population. Further studies are needed to elucidate its potential association with cardiovascular events and kidney disease progression.

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

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

Soluble suppression of tumorigenicity 2 associated with major adverse cardiac events in children with myocarditis

Objective

Soluble suppression of tumorigenicity 2 (sST2) is associated with the prognosis of some cardiac diseases, but studies on sST2 and the prognosis of patients with myocarditis are rare. This study investigated the relationship between major adverse cardiovascular events (MACEs) and sST2 during hospitalization in pediatric patients with myocarditis.

Methods

This was a single-center retrospective cohort study. A total of 252 patients aged ≤14 years diagnosed with myocarditis were enrolled. Events during the hospitalization were defined as MACEs (all-cause death > new heart failure > ventricular arrhythmia).

Results

A total of 25 people had MACEs during their hospital stay. The mortality during hospitalization was 6/23 (26%) in patients with heart failure and 3/10 (30%) in patients with ventricular arrhythmias. After including these risk factors in a multivariate logistic regression analysis, NT-proBNP (OR 4.323; 95% CI, 2.433-7.679; p < 0.001) and sST2 (OR 1.020; 95% CI, 1.003-1.037; p = 0.022) remained statistically significant and were independent risk factors for MACEs during hospitalization in pediatric myocarditis patients.

Conclusions

Elevated levels of NT-proBNP and sST2 were independently associated with major adverse cardiovascular events during hospitalization in children with myocarditis, and both showed good predictive efficacy.

Clinical markers in heart failure: a narrative review

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

Global longitudinal strain and plasma biomarkers for prognosis in heart failure complicated by diabetes: a prospective observational study

BACKGROUND

Heart failure (HF) and diabetes are associated with increased incidence and worse prognosis of each other. The prognostic value of global longitudinal strain (GLS) measured by cardiovascular magnetic resonance (CMR) has not been established in HF patients with diabetes.

METHODS

In this prospective, observational study, consecutive patients (n = 315) with HF underwent CMR at 3T, including GLS, late gadolinium enhancement (LGE), native T1, and extracellular volume fraction (ECV) mapping. Plasma biomarker concentrations were measured including: N-terminal pro B-type natriuretic peptide(NT-proBNP), high-sensitivity troponin T(hs-TnT), growth differentiation factor 15(GDF-15), soluble ST2(sST2), and galectin 3(Gal-3). The primary outcome was a composite of all-cause mortality or HF hospitalisation.

RESULTS

Compared to those without diabetes (n = 156), the diabetes group (n = 159) had a higher LGE prevalence (76 vs. 60%, p < 0.05), higher T1 (1285±42 vs. 1269±42ms, p < 0.001), and higher ECV (30.5±3.5 vs. 28.8±4.1%, p < 0.001). The diabetes group had higher NT-pro-BNP, hs-TnT, GDF-15, sST2, and Gal-3. Diabetes conferred worse prognosis (hazard ratio (HR) 2.33 [95% confidence interval (CI) 1.43-3.79], p < 0.001). In multivariable Cox regression analysis including clinical markers and plasma biomarkers, sST2 alone remained independently associated with the primary outcome (HR per 1 ng/mL 1.04 [95% CI 1.02-1.07], p = 0.001). In multivariable Cox regression models in the diabetes group, both GLS and sST2 remained prognostic (GLS: HR 1.12 [95% CI 1.03-1.21], p = 0.01; sST2: HR per 1 ng/mL 1.03 [95% CI 1.00-1.06], p = 0.02).

CONCLUSIONS

Compared to HF patients without diabetes, those with diabetes have worse plasma and CMR markers of fibrosis and a more adverse prognosis. GLS by CMR is a powerful and independent prognostic marker in HF patients with diabetes.

The Effectiveness of Outpatient Treatment Under the Control of the Soluble ST2 Receptor Concentration in Patients With Heart Failure With Reduced Ejection Fraction After Acute Decompensation of Heart Failure

Aim    To study the effectiveness of a treatment based on monitoring the soluble ST2 receptor (sST2) concentration in patients with chronic heart failure (CHF) with reduced left ventricular ejection fraction (LVEF) after acute decompensated heart failure (ADHF).Material and methods    The study included 37 patients hospitalized for ADHF with LVEF ≤40% and sST2 concentration ≥37.8 ng/ml at the time of discharge from the hospital. Patients were randomized into two groups: a sST2 monitoring (sST2M) group (19 patients) and a standard therapy (ST) group (18 patients). The follow-up period was 12 months. At baseline, the groups practically did not differ by clinical, functional, laboratory, and instrumental characteristics. For the sST2M group, the goal was reducing the sST2 concentration by >30% of baseline or to <30 ng/ml.Results    Therapy in both groups was comparable both in doses and in frequency of administration of basic drugs. However, the diuretic therapy was more frequently adjusted in the sST2M group (3.0 [1.0; 4.0] vs. 1.0 [0; 3.0] adjustments per patient, p = 0.047), which required more visits to the clinic (7.0 [6.0; 9.0] vs. 6.0 [6.0; 6.0] visits per patient, p=0.024). In the sST2M group at 6 months, the sST2 concentration was decreased by 43.3% (p=0.001), and 13 patients (72.2%) achieved the goal. In the ST group, the sST2 concentration was decreased by 38.5% (p=0.001), and 11 patients (68.8%) reached the target values. After 12 months, the downward trend continued in both groups. In both groups, the NT-proBNP concentration decreased: in the sST2M group by 27.7% (p=0.014), and in the ST group by 31.9% (p = 0.006). By the 12th month, the decrease remained only in the sST2M group. Only the sST2M group had an increase in LVEF (+28.5%, p=0.003), a decrease in left ventricular end-systolic volume (LVESV) (-12.0%, p=0.017), and a decrease in left atrial volume (-13.4%, p=0.045); at 12 months, LVEF remained increased (26%, p=0.006), and LA volume remained decreased (-14.3%, p=0.028). Quality of life and results of 6-minute walk test (6MWT) improved in both groups. For 6 months of treatment, the sST2M group had a significantly lower incidence of composite endpoints (CEP, cardiovascular death and decompensation/hospitalization due to HF), 26.3% (5 events) of the sST2M group compared to the ST group, 83.3% (15 events) (p=0.029), primarily due to a lower incidence of decompensated HF. For 12 months of follow-up, the incidence of CEP in the ST group was 122.2% (22 events), and 47.4% (9 events) in the sST2M group (p=0.035).Conclusions    The tactics of sST2 monitoring used in the treatment of "high-risk" HFrEF patients (with high sST2 concentrations) is associated with increased LVEF, improved functional status of patients, a beneficial effect on LV remodeling, and decreased incidence of CEP.

Serum-soluble suppression of tumourigenicity-2 as a biomarker in children with congestive heart failure

BACKGROUND

We aimed to evaluate serum soluble suppression of tumorigenicity-2 in children with congestive heart failure, to assess the diagnostic and prognostic values of soluble suppression of tumorigenicity-2 in these patients, and to correlate its levels with various clinical and echocardiographic data.

METHODS

We included 60 children with congestive heart failure as the patient group. Sixty healthy children of matched age and sex served as the control group. Patients were evaluated clinically and by echocardiography. Serum level of suppression of tumorigenicity-2 was measured for patients at admission. All patients were followed up for death or readmission for a period of one year.

RESULTS

Soluble suppression of tumorigenicity-2 was significantly higher in children with congestive heart failure as compared to the control group. Soluble suppression of tumorigenicity-2 was significantly increased in patients with higher severity of congestive heart failure. There was a significant increase in soluble suppression of tumorigenicity-2 in patients with bad prognosis compared to those with good prognosis. There was a significant positive correlation between soluble suppression of tumorigenicity-2 and respiratory rate, heart rate, and clinical stage of congenital heart failure, while there was a significant negative correlation between soluble suppression of tumorigenicity-2 and left ventricular systolic and diastolic function. The best cut-off of soluble suppression of tumorigenicity-2 to diagnose congestive heart failure was > 3.6 with 87% sensitivity and 79% specificity. The cut-off point of soluble suppression of tumorigenicity-2 to diagnose congestive heart failure in children was ≥ 31.56 ng/ml, with 95% sensitivity and 91.37% specificity. Moreover, the cut-off point of soluble suppression of tumorigenicity-2 to predict bad prognosis in children with congestive heart failure was ≥ 255.5 ng/ml, with 92% sensitivity and 89.0% specificity.

CONCLUSION

Soluble suppression of tumorigenicity-2 is a good diagnostic and predictive biomarker in children with congestive heart failure.

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).

Protective effect of canagliflozin on post-resuscitation myocardial function in a rat model of cardiac arrest

BACKGROUND

Currently, most patients with cardiac arrest (CA) show reversible myocardial dysfunction, hemodynamic instability, systemic inflammation and other pathophysiological state in early stage of resuscitation, some patients may eventually progress to multiple organ failure. There is evidence that heart failure is the terminal stage in the development of various cardiovascular diseases. Although the cardio-protective effect of canagliflozin (CANA) has been confirmed in large clinical studies and recommended in domestic and international heart failure-related guidelines, the effectiveness of CANA after resuscitation remains unclear. In this study, we constructed a modified CA/CPR rat model to investigate whether CANA administered on post-resuscitation improves myocardial function.

METHODS

Twenty-fourth healthy male Sprague-Dawley rats were randomized into four groups: (1) Sham + placebo group, (2) Sham + CANA group, (3) CPR + placebo group, and (4) CPR + CANA group. Ventricular fibrillation was induced by transcutaneous electrical stimulation on epicardium. After 6 min untreated ventricular fibrillation, chest compressions was initiated. The rats were received an injection of placebo or canagliflozin (3 ug/kg) randomly 15 min after restore of spontaneous circulation (ROSC). Electrocardiogram (ECG) and blood pressure were continuously detected in each group throughout the experiment. The rats were killed 6 h after ROSC to collected the arterial serum and myocardial tissue. Myocardial injury was estimated with concentrations of inflammatory factors, oxidative stress indexes and, apoptosis index, myocardial injury markers, echocardiography and myocardial pathological slices.

RESULTS

After resuscitation, mean arterial pressure (MAP) were significantly increased after cardiopulmonary resuscitation in CANA group rats when compared with placebo group. Heart rate, body lactate returned and left ventricular ejection fraction (LVEF) to normal levels in a shorter time and the myocardial injury was obviously attenuated in CPR + CANA group. Inflammatory factors (IL-6, TNF-α) and oxidative stress indexes (MAD, SOD, CAT) were dramatically decreased with the administration of CANA. The expression of apoptosis index (BAX, caspase-3) were higher in CPR + placebo group and the expression of anti-apoptosis index (Bcl-2) was lower (P < 0.05).

CONCLUSIONS

The administration of CANA effectively reduces myocardial ischaemia/reperfusion (I/R) injury after cardiac arrest and cardiopulmonary resuscitation (CPR), and the underlying mechanism may be related to anti-inflammation, oxidative stress and apoptosis.

Biomarkers to Improve Decision-making in Acute Heart Failure

Acute heart failure (AHF) is a complex clinical syndrome that requires prompt diagnosis, risk stratification and effective treatment strategies to reduce morbidity and mortality. Biomarkers are playing an increasingly important role in this process, offering valuable insights into the underlying pathophysiology and facilitating personalised patient management. This review summarises the significance of various biomarkers in the context of AHF, with a focus on their clinical applications to stratify risk and potential for guiding therapy choices.

Metformin effects on cardiac parameters in non-diabetic Iraqi patients with heart failure and mid-range ejection fraction - a comparative two-arm parallel clinical study

Heart failure (HF) remains a difficult challenge to the healthcare system, necessitating promoting interventions and multidrug management. Metformin, typically used to manage diabetes, has emerged as a promising intervention in the treatment of HF. This study aimed to assess the effect of adding metformin to the standard treatment of HF on cardiac parameters. This clinical study comprised 60 newly diagnosed HF patients randomly assigned to two groups: Group C received standard HF treatment, while Group M received standard HF treatment in addition to daily metformin (500 mg). After 3 months of treatment, group M showed a significantly higher ejection fraction (EF) compared to Group C (6.1% and 3.2%, respectively; p-value=0.023) and a reduction in the left ventricular end-diastolic pressure (LVEDD) (0.28, and 0.21 mm respectively; p-value=0.029). No significant differences were observed in the interventricular septal thickness (IVST) or left ventricular end-systolic pressure (LVESD). For cardiac markers, N-Terminal pro-BNP (NT-proBNP) showed the highest reduction in Group M compared to Group C (719.9 pg/ml and 271.9 pg/ml respectively; p-value=0.009). No significant changes were reported for soluble ST2. Metformin demonstrated cardiac protective effects by increasing EF and reducing NT-proBNP. Given its affordability and accessibility, metformin offers a valuable addition to the current HF treatment options. This positive effect may be attributed to mechanisms that enhance the impact of conventional HF treatments or vice versa.

Korean Society of Heart Failure Guidelines for the Management of Heart Failure: Definition and Diagnosis

The Korean Society of Heart Failure guidelines aim to provide physicians with evidence-based recommendations for diagnosing and managing patients with heart failure (HF). In Korea, the prevalence of HF has been rapidly increasing in the last 10 years. HF has recently been classified into HF with reduced ejection fraction (HFrEF), HF with mildly reduced ejection fraction (EF), and HF with preserved EF (HFpEF). Moreover, the availability of newer therapeutic agents has led to an increased emphasis on the appropriate diagnosis of HFpEF. Accordingly, this part of the guidelines will mainly cover the definition, epidemiology, and diagnosis of HF.

Korean Society of Heart Failure Guidelines for the Management of Heart Failure: Definition and Diagnosis

The Korean Society of Heart Failure guidelines aim to provide physicians with evidence-based recommendations for diagnosing and managing patients with heart failure (HF). In Korea, the prevalence of HF has been rapidly increasing in the last 10 years. HF has recently been classified into HF with reduced ejection fraction (EF), HF with mildly reduced EF, and HF with preserved EF (HFpEF). Moreover, the availability of newer therapeutic agents has led to an increased emphasis on the appropriate diagnosis of HFpEF. Accordingly, this part of the guidelines will mainly cover the definition, epidemiology, and diagnosis of HF.

The role of serial cardiac biomarkers in prognostication and risk prediction of chronic heart failure: additional scientific insights with hemodynamic feedback

INTRODUCTION

Heart failure (HF) is considered as a chronic long-term and lethal disease and will continue to be a major public health problem. Studying (circulating) biomarkers is a promising field of research and could be the first step toward HF tailored prognostic strategies as well as understanding the response to HF drugs in CHF patients.

AREAS COVERED

In literature, there has been considerable research on elevated biomarker levels that are related to a poor prognosis for HF. Since biomarker levels change over time, it is important to study serial (repeated) biomarker measurements which may help us better understand the dynamic course of HF illness. However, the majority of research focuses predominantly on baseline values of biomarkers. Additionally, remote monitoring devices, like sensors, can be used to link hemodynamic information to freshen biomarker data in order to further ameliorate the management of HF.

EXPERT OPINION

Novel biomarkers and additional scientific insights with hemodynamic feedback strongly aid in the prognostication and risk prediction of chronic HF.

Biomarker sST2 in Adults with Transposition of the Great Arteries Palliated by Mustard Procedure: A Five-Year Follow-up

The Mustard procedure was an early cardiac surgery for transposition of the great arteries (TGA). Despite being successful, it has been associated with long-term arrhythmias and heart failure. A key factor complicating management in adults with congenital heart disease (CHD) is the deficiency of biomarkers predicting outcome. Soluble suppression of tumorogenicity-2 (sST2) is secreted by cardiomyocytes in response to mechanical strain and fibrosis. We hypothesized that adults with a Mustard procedure would have higher levels of sST2 than healthy individuals, and this would correlate with clinical outcome. We performed a single-center study in patients managed during childhood with a Mustard procedure versus age-matched controls. Clinical and demographic data were collected and biomarkers (sST2, cTnI, BNP, lipid panel, insulin, and glucose) were obtained. There were 18 patients (12 male) in the Mustard cohort and 18 patients (6 male) in the control group (22-49 years, mean of 35.8 vs. mean 32.6 years, respectively, p = ns). Nine Mustard subjects were NYHA class II, and 9 subjects were class III. The control group was asymptomatic. sST2 in the Mustard group was elevated in 56% vs. 17% in controls (p = 0.035). Of the Mustard subjects with elevated sST2, 60% had elevated cTnI and BNP, and 90% had low HDL. Over five years, the Mustard patients with elevated sST2 values had greater medication use, arrhythmias, hospitalizations, and ablation/pacer implantations than Mustard subjects with normal sST2. Mustard subjects with elevated sST2 had other biomarker abnormalities and clinically worse outcomes. Thus, sST2 may add a predictive value to cardiac-related morbidity and mortality.

Soluble urokinase plasminogen activator receptor and survival in elective cardiac surgery

BACKGROUND

The study investigated the prognostic value of soluble urokinase plasminogen activator receptor (suPAR) in patients undergoing cardiac surgery and calculated a simplified biomarker score comprising suPAR, N-terminal pro B-type natriuretic peptide (NT-proBNP) and age.

METHODS AND RESULTS

Biomarkers were assessed in a cohort of 478 patients undergoing elective cardiac surgery. After a median follow-up of 4.2 years, a total of 72 (15.1%) patients died. SuPAR, NT-proBNP and age were independent prognosticators of mortality in a multivariable Cox regression model after adjustment for EuroScoreII. We then calculated a simplified biomarker score comprising age, suPAR and NT-proBNP, which had a superior prognostic value compared to EuroScoreII (Harrel's C of 0.76 vs. 0.72; P for difference = 0.02). Besides long-term mortality, the biomarker score had an excellent performance predicting one-year mortality and hospitalization due to heart failure.

CONCLUSION

The biomarker suPAR and NT-proBNP were strongly and independently associated with mortality in patients undergoing cardiac surgery. A simplified biomarker score comprising only three variables (age, suPAR and NT-proBNP) performed better than the established EuroScoreII with respect to intermediate and long-term outcome as well as hospitalization due to heart failure. As such, integration of established and upcoming biomarkers in clinical practice may provide improved decision support in cardiac surgery.

Dynamics of NT-proBNP and ST2 levels as markers of heart failure in patients with endogenous Cushing syndrome (hypercortisolism)

Aim. To evaluate frequency of heart failure syndrome in patients with endogenous hypercortisolism and to establish relationship between effective treatment for hypercortisolism and regression of heart failure with particular emphasis on the observation of NT-proBNP and ST2 levels. Materials and methods. 56 patients with endogenous hypercortisolism (45 female, mean age 47 years [36; 55] hospitalized with endogenous hypercortisolism to National Medical Research Center for Endocrinology were enrolled in the study. All patients underwent comprehensive clinical investigation including expert echocardiography with speckle tracking and evaluation of NT-proBNP and ST2 cardiac biomarkers at baseline and 6 months after surgical treatment. Results. According to clinical data and elevated biomarkers of cardiac stress 28 out of 56 patients (50%) at baseline met the criteria for heart failure. 20 patients were included in the final analysis. Follow-up investigation with focus on changes in NT-proBNP and ST2 levels demonstrated that surgical correction of endogenous hypercortisolism resulted in resolution of heart failure syndrome in 11 patients (55%). Conclusion. These preliminary data suggest that signs and symptoms of heart failure are observed in patients with endogenous hypercortisolism in about half the cases. Surgical correction results in resolution of heart failure in approximately two thirds of the cases. Prospective evaluation NT-proBNP and ST2 levels may provide important diagnostic and prognostic information in patients with endogenous hypercortisolism.

Inflammageing and Cardiovascular System: Focus on Cardiokines and Cardiac-Specific Biomarkers

The term "inflammageing" was introduced in 2000, with the aim of describing the chronic inflammatory state typical of elderly individuals, which is characterized by a combination of elevated levels of inflammatory biomarkers, a high burden of comorbidities, an elevated risk of disability, frailty, and premature death. Inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and rapid progression to heart failure. The great experimental and clinical evidence accumulated in recent years has clearly demonstrated that early detection and counteraction of inflammageing is a promising strategy not only to prevent cardiovascular disease, but also to slow down the progressive decline of health that occurs with ageing. It is conceivable that beneficial effects of counteracting inflammageing should be most effective if implemented in the early stages, when the compensatory capacity of the organism is not completely exhausted. Early interventions and treatments require early diagnosis using reliable and cost-effective biomarkers. Indeed, recent clinical studies have demonstrated that cardiac-specific biomarkers (i.e., cardiac natriuretic peptides and cardiac troponins) are able to identify, even in the general population, the individuals at highest risk of progression to heart failure. However, further clinical studies are needed to better understand the usefulness and cost/benefit ratio of cardiac-specific biomarkers as potential targets in preventive and therapeutic strategies for early detection and counteraction of inflammageing mechanisms and in this way slowing the progressive decline of health that occurs with ageing.

A Peek at LVADs Pumping to Recovery

Left ventricular assist devices (LVADs) have revolutionized the management of patients with advanced heart failure refractory to medical therapy. Current indications of LVADs include Bridge to Transplantation (BTT), Destination Therapy (DT) for long-term use, Bridge to the Decision (BTD) used as a temporary measure, and lastly Bridge to Recovery (BTR). Here, we briefly review the clinical evidence and the molecular mechanisms behind myocardial recovery following LVAD placement. We also share institutional protocols used at 2 major medical centers in the USA.

GDF-15 and soluble ST2 as biomarkers of right ventricular dysfunction in pulmonary hypertension

Background: This study analyzed the utility of soluble ST2 (sST2) and GDF-15 as biomarkers of right ventricular (RV) function in patients with pulmonary hypertension (PH). Methods: GDF-15 and sST2 serum concentrations were measured in patients with PH (n = 628), dilated cardiomyopathy (n = 31) and left ventricular hypertrophy (n = 47), and in healthy controls (n = 61). Results: Median sST2 and GDF-15 levels in patients with left ventricular hypertrophy were higher than in patients with PH and dilated cardiomyopathy. In tertile analysis GDF-15 >1363 pg/ml and sST2 >38 ng/ml were associated with higher N-terminal pro-brain natriuretic peptide, RV systolic dysfunction, RV-pulmonary arterial uncoupling and hemodynamic impairment. Conclusion: GDF-15 and sST2 are potential biomarkers of RV dysfunction in patients with PH.

Practical Significance of Biomarkers in Axial Spondyloarthritis: Updates on Diagnosis, Disease Activity, and Prognosis

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that can lead to ankylosis by secondary ossification of inflammatory lesions, with progressive disability and a significant impact on quality of life. It is also a risk factor for the occurrence of comorbidities, especially cardiovascular diseases (CVDs), mood disorders, osteoporosis, and malignancies. Early diagnosis and treatment are needed to prevent or decrease functional decline and to improve the patient's prognosis. In respect of axSpA, there is an unmet need for biomarkers that can help to diagnose the disease, define disease activity and prognosis, and establish personalized treatment approaches. The aim of this review was to summarize the available information regarding the most promising biomarkers for axSpA. We classified and identified six core categories of biomarkers: (i) systemic markers of inflammation; (ii) molecules involved in bone homeostasis; (iii) HLA-B27 and newer genetic biomarkers; (iv) antibody-based biomarkers; (v) microbiome biomarkers; and (vi) miscellaneous biomarkers. Unfortunately, despite efforts to validate new biomarkers, few of them are used in clinical practice; however, we believe that these studies provide useful data that could aid in better disease management.

Biomarkers to Predict Sudden Cardiac Death

Sudden cardiac death (SCD) is a common disorder and an unsolved issue for health care providers. Despite several risk factors for SCD, some cases experience SCD as an initial presentation of cardiovascular disease. Prediction of individuals at increased risk for SCD is important for implementing community-based approaches and individual-based therapies with high costs, such as implantable defibrillators. This chapter discusses the potential role of biomarkers in predicting SCD in different cardiovascular diseases.

GDF-15 and sST-2 act as biomarkers of disease severity but not independent predictors in idiopathic membranous nephropathy

BACKGROUND

We aimed to explore biomarkers of disease severity in idiopathic membranous nephropathy (IMN) and independent predictors of prognosis in IMN.

METHODS

Clinical data were collected from 79 IMN patients. Serum levels of growth differentiation factor-15 (GDF-15) and soluble suppression of tumorigenicity (sST-2) were tested by enzyme-linked immunosorbent assay (ELISA) in IMN patients and subgroups, and correlation analysis was performed. Univariate and multiple logistic regression analyses were performed to identify independent predictors of IMN, and a combined-factors model was constructed. Moreover, the area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the prognostic efficacy.

RESULTS

The levels of GDF-15 were significantly higher in the IMN group and subgroups with low estimated glomerular filtration rate (eGFR) and high 24 hour-urine protein (24 h-UP), whiles sST-2 level was only significantly higher in the IMN group. GDF-15 levels were positively correlated with creatinine (Crea), cystatin C (Cys-C) and 24 h-UP and negatively correlated with GFR and albumin (Alb), while sST-2 levels were positively correlated with Urea and Cys-C and negatively correlated with eGFR. After one year of follow-up, 54 patients had incomplete remission. Serum phospholipase A2 receptor antibody (PLA2R-Ab), Urea, high-density lipoprotein cholesterol (HDL-C) and 24 h-UP but not GDF-15 and sST2 were independent predictors of prognosis in IMN patients, but combined factors showed the best prognostic efficacy.

CONCLUSION

Serum levels of GDF-15 and sST-2 may be potential biomarkers for the severity of IMN, while the combined-factors model is effective for predicting the risk factors of incomplete remission in IMN.

Soluble Isoform of Suppression of Tumorigenicity 2 (ST2) Biomarker in a Large Cohort of Healthy Pediatric Population: Determination of Reference Intervals

Introduction: Only little data exists on ST2 reference intervals in healthy pediatric populations despite the high importance of this biomarker in adults with heart failure. The aim of the study was to assess the reference intervals of ST2 in a wide healthy pediatric cohort. Methods: We evaluated the serum concentrations of ST2 biomarker in 415 healthy pediatric subjects referred to our analysis laboratory. Subjects were categorized according to age (i.e., 0−6 (n = 79), 7−11 (n = 142) and 12−18 years (n = 191)) and sex. They were not suffering from any cardiac disorders, metabolic disorders, lung diseases, autoimmune disorders or malignancies. A written consent was obtained for each individual. No duplicate patients were included in the analysis and the presence of outliers was investigated. Reference intervals (Mean and central 95% confidence intervals) were determined. Results: Three outliers have been identified and removed from the analysis (60.0, 64.0 and 150.2 ng/mL). A total of 412 subjects were therefore included. The mean value for the whole population was 15.8 ng/mL (2.4−36.4 ng/mL). Males present a significantly higher mean concentration compared to females (17.2 versus 14.4 ng/mL, p = 0.001). A significant trend toward higher ST2 values with age was also observed, but for males only (r = 0.43, p < 0.0001). If considering age partitions, only males of 12−18 years (mean = 21.7 ng/mL) had significantly higher ST2 values compared to the other groups (ranging from 11.9 for males 0−6 years to 15.2 for females 12−18 years; p < 0.0001). Conclusions: We described age and sex-specific reference intervals for ST2 in a large healthy pediatric population. We found that ST2 values differ between sexes if considering all participants. A significant increase in ST2 with age was also observed, but only for males of 12−18 years.

Biomarkers of HFpEF: Natriuretic Peptides, High-Sensitivity Troponins and Beyond

Heart failure (HF) is a significant cause of morbidity and mortality worldwide. HF with preserved ejection fraction (HFpEF) is a complex syndrome, often participated by several cardiac and extracardiac conditions, including chronic kidney disease, pulmonary disease, anaemia and advanced age. Circulating biomarkers reflecting pathophysiological pathways involved in HFpEF development and progression may assist clinicians in early diagnosis and management of this condition. Natriuretic peptides (NPs) are cardioprotective hormones released by cardiomyocytes in response to pressure or volume overload and in response to activation of neuro-endocrine-immune system. The relevance of B-type NP (BNP) and N-terminal pro-B-type NP (NT-proBNP) for diagnosis and risk stratification has been extensively demonstrated, and these biomarkers are emerging tools for population screening and as guides to the start of treatment in subclinical HF. On the contrary, conflicting evidence exists on the value of NPs to guide HF therapy. Among the other biomarkers, high-sensitivity troponins and soluble suppression of tumorigenesis-2 are the most promising biomarkers for risk stratification, predicting outcome independently from NPs. In this review, some novel biomarkers are being tested in such clinical scenario, more tightly linked to specific pathophysiological processes of cardiac damage.

Biomarker prognostication across Universal Definition of Heart Failure stages

AIM

The Universal Definition of Heart Failure (UDHF) provides a framework for staging risk for HF events. It is not clear whether prognostic biomarkers have different meaning across UDHF stages. We sought to evaluate performance of biomarkers to predict HF events among high-risk patients undergoing coronary and/or peripheral angiography categorized into UDHF stages.

METHODS

One thousand two hundred thirty-five individuals underwent coronary and/or peripheral angiography were enrolled. Study participants were categorized into UDHF Stage A (at risk), Stage B (pre-HF), and Stage C or D (HF, including end stage) and grouped into Stage A/B and C/D. Biomarkers and clinical variables were used to develop prognostic models. Other measures examined included total HF hospitalizations.

RESULTS

Over a median of 3.67 years of follow-up, 155 cardiovascular (CV) deaths occurred, and 299 patients were hospitalized with acute HF. In patients with Stage A/B, galectin-3 (HR = 1.52, P = 0.03), endothelin-1 (HR = 2.16, P = 0.001), and N-terminal pro-B-type natriuretic peptide (NT-proBNP; HR = 1.43, P < 0.001) were associated with incident CV death/HF hospitalization. In Stage C/D, NT-proBNP (HR = 1.26, P = 0.006), soluble urokinase-type plasminogen activator receptor (suPAR; HR = 1.57, P = 0.007) and high-sensitivity C-reactive protein (hs-CRP; HR = 1.15, P = 0.01) were associated with these outcomes. Higher biomarker concentrations were associated with greater total burden of HF events in Stages A/B and C/D.

CONCLUSIONS

Among higher risk individuals undergoing angiographic procedures, different biomarkers improve risk stratification in different UDHF stages of HF. More precise prognostication may offer a window of opportunity to initiate targeted preventive measures.

Comparison of serum biomarkers of myocardial fibrosis with cardiac magnetic resonance in patients operated for tetralogy of Fallot

BACKGROUND

Serum biomarkers of myocardial fibrosis are considered markers of adverse outcome in adults with heart disease. Associations between biomarkers and clinical parameters in tetralogy of Fallot (TOF) has been understudied. We compared serum biomarker profiles with clinical and cardiac magnetic resonance (CMR) parameters of ventricular remodeling in patients with repaired TOF.

METHODS

Serum biomarkers [metalloproteinases MMP1 and MMP9, galectin-3, micro-RNA21 (miR21)), ST2, procollagen type I carboxy-terminal propeptide (PICP), and NTproBNP] were measured in TOF patients undergoing CMR. Associations between biomarkers and clinical and CMR variables were assessed using correlation coefficients, and linear and logistic regression.

RESULTS

Sixty patients were investigated, of which 47% were male. Age at CMR and TOF repair was 15 years [interquartile range (IQR) 9, 22] and 3.2 months (IQR 0.8, 6.2), respectively. Twelve (20%) had prior pulmonary valve replacement (PVR). MMP1 values were higher among those with prior PVR (16.7 (IQR 7.9, 25.5) vs 14.4 (IQR 9.9, 24.9), p = 0.02). When stratifying MMP1 into low and high groups, higher MMP1 was associated with higher indexed right (RV) and left ventricular (LV) mass and RV mass:volume ratios after adjusting for PVR. No other associations between biomarkers and CMR parameters were identified.

CONCLUSIONS

Only MMP1 was associated with markers of RV remodeling after TOF repair. As an enzyme involved in extracellular matrix degradation, MMP1 could be associated with fibrotic processes underlying RV remodeling, including dilation and hypertrophy. The additional biomarkers may not be specific towards cardiac remodeling. These findings merit further correlations with myocardial fibrosis measurements by CMR.

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

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

New strategies and therapies for the prevention of heart failure in high-risk patients

Despite declines in total cardiovascular mortality rates in the United States, heart failure (HF) mortality rates as well as hospitalizations and readmissions have increased in the past decade. Increases have been relatively higher among young and middle-aged adults (<65 years). Therefore, identification of individuals HF at-risk (Stage A) or with pre-HF (Stage B) before the onset of overt clinical signs and symptoms (Stage C) is urgently needed. Multivariate risk models (e.g., Pooled Cohort Equations to Prevent Heart Failure [PCP-HF]) have been externally validated in diverse populations and endorsed by the 2022 HF Guidelines to apply a risk-based framework for the prevention of HF. However, traditional risk factors included in the PCP-HF model only account for half of an individual's lifetime risk of HF; novel risk factors (e.g., adverse pregnancy outcomes, impaired lung health, COVID-19) are emerging as important risk-enhancing factors that need to be accounted for in personalized approaches to prevention. In addition to determining the role of novel risk-enhancing factors, integration of social determinants of health (SDoH) in identifying and addressing HF risk is needed to transform the current clinical paradigm for the prevention of HF. Comprehensive strategies to prevent the progression of HF must incorporate pharmacotherapies (e.g., sodium glucose co-transporter-2 inhibitors that have also been termed the "statins" of HF prevention), intensive blood pressure lowering, and heart-healthy behaviors. Future directions include investigation of novel prediction models leveraging machine learning, integration of risk-enhancing factors and SDoH, and equitable approaches to interventions for risk-based prevention of HF.

Cardiac remodelling - Part 1: From cells and tissues to circulating biomarkers. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

Cardiac remodelling refers to changes in left ventricular structure and function over time, with a progressive deterioration that may lead to heart failure (HF) development (adverse remodelling) or vice versa a recovery (reverse remodelling) in response to HF treatment. Adverse remodelling predicts a worse outcome, whilst reverse remodelling predicts a better prognosis. The geometry, systolic and diastolic function and electric activity of the left ventricle are affected, as well as the left atrium and on the long term even right heart chambers. At a cellular and molecular level, remodelling involves all components of cardiac tissue: cardiomyocytes, fibroblasts, endothelial cells and leucocytes. The molecular, cellular and histological signatures of remodelling may differ according to the cause and severity of cardiac damage, and clearly to the global trend toward worsening or recovery. These processes cannot be routinely evaluated through endomyocardial biopsies, but may be reflected by circulating levels of several biomarkers. Different classes of biomarkers (e.g. proteins, non-coding RNAs, metabolites and/or epigenetic modifications) and several biomarkers of each class might inform on some aspects on HF development, progression and long-term outcomes, but most have failed to enter clinical practice. This may be due to the biological complexity of remodelling, so that no single biomarker could provide great insight on remodelling when assessed alone. Another possible reason is a still incomplete understanding of the role of biomarkers in the pathophysiology of cardiac remodelling. Such role will be investigated in the first part of this review paper on biomarkers of cardiac remodelling.

The Prognostic Role of ST2L and sST2 in Patients Who Underwent Carotid Plaque Endarterectomy: A Five-Year Follow-Up Study

Soluble suppressor of tumorigenicity (sST)-2 plasma concentration is related to atherosclerosis. The aim of this study was to assess the prognostic impact of sST2 and its membrane-associated form (ST2L) in patients with carotid atherosclerotic plaque who underwent endarterectomy (CEA). Eighty-two consecutive patients (age range: 48−86 years) who underwent CEA were enrolled. Anthropometric, clinical, instrumental, and laboratory evaluations were gathered. Thirty-seven (45%) patients were symptomatic of cerebrovascular diseases. Patients underwent a five-year follow-up. Phone calls and the analysis of national and regional databases were performed in order to evaluate the occurrence of the primary outcome (all-cause mortality). The population was divided according to survival status. Statins were administered in 81% and 87.5% of survivors and non-survivors, respectively. sST2 levels were higher in non-survivors than in survivors (117.0 ± 103.9 vs. 38.0 ± 30.0 ng/mL, p < 0.001) and in symptomatic individuals, compared with asymptomatic (80.3 ± 92.1 ng/mL vs. 45.4 ± 41.4 ng/mL, p = 0.02). ROC curve analysis identified sST2 cut-off: >98.44 ng/mL as the best predictor for mortality. At the one-year follow-up, the survival rate decreased up to 20% in patients with sST2 higher than the cut-off value. A multivariate regression analysis revealed that only sST2 (HR: 1.012, 95% CI: 1.008−1.016, p < 0.0001) and triglycerides plasma levels (HR: 1.008, 95% CI: 1.002−1.015, p = 0.0135) remained significantly associated with all-cause mortality. ST2L was not associated with all-cause mortality risk. sST2 may act as an independent prognostic determinant of all-cause mortality and symptomatic cerebrovascular diseases in patients with carotid atherosclerotic plaque who underwent CEA.

Cardiovascular Biomarkers: Lessons of the Past and Prospects for the Future

Cardiovascular diseases (CVDs) are a major healthcare burden on the population worldwide. Early detection of this disease is important in prevention and treatment to minimise morbidity and mortality. Biomarkers are a critical tool to either diagnose, screen, or provide prognostic information for pathological conditions. This review discusses the historical cardiac biomarkers used to detect these conditions, discussing their application and their limitations. Identification of new biomarkers have since replaced these and are now in use in routine clinical practice, but still do not detect all disease. Future cardiac biomarkers are showing promise in early studies, but further studies are required to show their value in improving detection of CVD above the current biomarkers. Additionally, the analytical platforms that would allow them to be adopted in healthcare are yet to be established. There is also the need to identify whether these biomarkers can be used for diagnostic, prognostic, or screening purposes, which will impact their implementation in routine clinical practice.

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.

Circulating levels and prognostic cut-offs of sST2, hs-cTnT, and NT-proBNP in women vs. men with chronic heart failure

Aims

To define plasma concentrations, determinants, and optimal prognostic cut‐offs of soluble suppression of tumorigenesis‐2 (sST2), high‐sensitivity cardiac troponin T (hs‐cTnT), and N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) in women and men with chronic heart failure (HF).

Methods and results

Individual data of patients from the Biomarkers In Heart Failure Outpatient Study (BIOS) Consortium with sST2, hs‐cTnT, and NT‐proBNP measured were analysed. The primary endpoint was a composite of 1 year cardiovascular death and HF hospitalization. The secondary endpoints were 5 year cardiovascular and all‐cause death. The cohort included 4540 patients (age 67 ± 12 years, left ventricular ejection fraction 33 ± 13%, 1111 women, 25%). Women showed lower sST2 (24 vs. 27 ng/mL, P < 0.001) and hs‐cTnT level (15 vs. 20 ng/L, P < 0.001), and similar concentrations of NT‐proBNP (1540 vs. 1505 ng/L, P = 0.408). Although the three biomarkers were confirmed as independent predictors of outcome in both sexes, the optimal prognostic cut‐off was lower in women for sST2 (28 vs. 31 ng/mL) and hs‐cTnT (22 vs. 25 ng/L), while NT‐proBNP cut‐off was higher in women (2339 ng/L vs. 2145 ng/L). The use of sex‐specific cut‐offs improved risk prediction compared with the use of previously standardized prognostic cut‐offs and allowed to reclassify the risk of many patients, to a greater extent in women than men, and for hs‐cTnT than sST2 or NT‐proBNP. Specifically, up to 18% men and up to 57% women were reclassified, by using the sex‐specific cut‐off of hs‐cTnT for the endpoint of 5 year cardiovascular death.

Conclusions

In patients with chronic HF, concentrations of sST2 and hs‐cTnT, but not of NT‐proBNP, are lower in women. Lower sST2 and hs‐cTnT and higher NT‐proBNP cut‐offs for risk stratification could be used in women.

Soluble ST2 Is a Sensitive and Specific Biomarker for Fulminant Myocarditis

Background

The aim of the study was to identify biomarkers that can facilitate early diagnosis and treatment of fulminant myocarditis (FM) in order to reduce mortality.

Methods and Results

First, the expression profiles of circulating cytokines were determined in the plasma samples from 4 patients with FM and 4 controls using human cytokine arrays. The results showed that 39 cytokines from patients with FM were changed at admission. Among them, 8 cytokines returned to normal levels at discharge, including soluble ST2 (sST2), which showed the most marked dynamic changes from disease onset to resolution. Then, in a cohort of 76 patients with FM, 57 patients with acute hemodynamic dysfunction attributable to other causes, and 56 patients with non‐FM, receiver operating characteristic curve analyses suggested that plasma sST2 level was able to differentiate FM from non‐FM or other FM‐unrelated acute heart failure more robustly N‐terminal pro‐B‐type natriuretic peptide or cardiac troponin I. Moreover, longitudinal analysis of plasma sST2 was performed in 10 patients with FM during hospitalization and 16 patients with FM during follow‐up. Finally, the diagnostic value was validated in an additional 26 patients with acute onset of unstable hemodynamics. The cutoff value of plasma sST2 for optimal diagnosis of FM was established at 58.39 ng/mL, where a sensitivity of 85.7% and specificity of 94.7% were achieved.

Conclusions

Elevated sST2 level was associated with mechanical stress or inflammation. Especially, sST2 might be used as a potential biomarker for the rapid diagnosis of FM, which was characterized by strong mechanical stretch stimulation and severe inflammatory response.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03268642.

Kinetics of Cardiac Remodeling and Fibrosis Biomarkers During an Extreme Mountain Ultramarathon

Objectives

The effects of ultra-distance on cardiac remodeling and fibrosis are unclear. Moreover, there are no data reporting the kinetics of cardiac alterations throughout the event and during recovery. Our aim was to investigate the kinetics of biological markers including new cardiac fibrosis biomarkers suppression of tumorigenicity 2 (ST2) and galectin-3 (Gal-3) during and after an extreme mountain ultramarathon.

Methods

Fifty experienced runners participating in one of the most challenging mountain ultramarathons (330 km, D+ 25,000 m) were enrolled in our study. Blood samples were collected at four time points: before (Pre-), at 148 km (Mid-), at the finish line (Post-), and 3 days after the recovery period (Recov-).

Results

The cardiac fibrosis biomarkers (ST2 and Gal-3) increased from Pre- to Mid-. During the second half, ST2 remained higher than pre-values as opposed to Gal-3. Necrosis, ischemia, and myocyte injury biomarkers increased until Mid- then decreased but remained higher at Recov- than Pre-values. Oxidative stress appeared at Mid-. Lipid peroxides remained higher at Recov- compared to Pre-. The maximal value in most of these biomarkers was observed at Mid- and not at Post-.

Conclusions

The present study supports biphasic kinetics of cardiac fibrosis biomarkers, with a relative recovery during the second half of the event that seems specific to this extreme event. Overall, performing at such an extreme ultramarathon seems less deleterious for the heart than shorter events.

Serum Soluble ST2 Is a Valuable Prognostic Biomarker in Patients With Acute Heart Failure

Background

This study aimed to investigate the clinical utility of different soluble suppression of tumorigenicity 2 (sST2) levels in assessing the severity and prognosis of patients with acute heart failure (AHF).

Methods

This was a prospective cohort study. Three hundred and thirty-one consecutively enrolled AHF patients from March 2018 to November 2019 were divided into 3 subgroups according to sST2 levels: T1 (1.15–7.70 ng/ml; N = 110), T2 (7.71–17.24 ng/ml; N = 111), and T3 (17.26–47.42 ng/ml; N = 110). The patients were followed up for a median period of 21.0 months for the development of the primary endpoint. Cox proportional hazards model was performed to evaluate the prognostic value of sST2 for the clinical outcomes.

Results

The mean age of patients was 69 years (range, 34–93 years), and 70.4% were male. During the follow-up period, 63 participants died. Patients with higher sST2 levels had lower left ventricular ejection fraction (correlation = −0.119, P = 0.031), and higher New York Heart Association classification (correlation = 0.443, P < 0.001) and N-terminal pro-B type natriuretic peptide (NT-proBNP) levels (correlation = 0.392, P < 0.001). Higher sST2 was also associated with creatinine, urea nitrogen, hemoglobin, and left ventricular mass index. Multivariate analysis revealed that sST2 (per log unit, hazard ratio: 2.174, 95% confidence interval [CI] 1.012–4.67, P = 0.047) and NT-proBNP (per log unit, HR 2.171, 95%CI 1.169–4.032, P < 0.001) were independent risk factors for the primary outcome in all patients with AHF.

Conclusion

sST2 can provide prognostic information in AHF. The higher the sST2 level in patients with AHF, the higher the incidence of cardiovascular death.

Biomarker Development in Cardiology: Reviewing the Past to Inform the Future

Cardiac biomarkers have become pivotal to the clinical practice of cardiology, but there remains much to discover that could benefit cardiology patients. We review the discovery of key protein biomarkers in the fields of acute coronary syndrome, heart failure, and atherosclerosis, giving an overview of the populations they were studied in and the statistics that were used to validate them. We review statistical approaches that are currently in use to assess new biomarkers and overview a framework for biomarker discovery and evaluation that could be incorporated into clinical trials to evaluate cardiovascular outcomes in the future.

Novel plasma biomarkers predicting biventricular involvement in arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease characterized by fibrofatty replacement of the myocardium and ventricular arrhythmias. Biventricular involvement in ARVC may lead to heart failure. This study aimed to investigate the role of plasma biomarkers soluble (s)ST2, Galectin-3 (Gal-3) and GDF-15 in predicting biventricular involvement and adverse outcomes in ARVC.

METHODS AND RESULTS

ARVC patients from 2 independent cohorts, were studied. The Bejing (Chinese) cohort (n = 108) was the discovery cohort, whereas the Zurich (Swiss) cohort (n = 47) served as validation. All patients had a definite ARVC diagnosis at time of blood withdrawal. Biomarkers were independently correlated with NT-proBNP and left ventricular (LV)-function. ARVC patients with LV involvement had higher levels of sST2 and GDF-15 as compared to controls and patients with isolated right ventricle (RV) involvement. sST2 and GDF-15 were significantly correlated with late gadolinium enhancement in CMR and with adverse heart failure outcomes. Gal-3 was elevated in ARVC patients with and without LV involvement. The combined use of the three biomarkers (sST2, GDF-15 and NT-proBNP) showed the best performance in predicting LV involvement in both cohorts. Plasma drawn from the coronary arteries and coronary sinus indicated a transmyocardial elevation of sST2, but no transmyocardial gradient of GDF-15. After heart transplantation, both sST2 and GDF-15 returned to near-normal levels.

CONCLUSION

Our study showed that sST2 and GDF-15 may predict biventricular involvement in ARVC. The combined use of sST2, GDF-15 and NT-proBNP showed the best prediction of biventricular involvement in ARVC.

Soluble ST2 Receptor: Biomarker of Left Ventricular Impairment and Functional Status in Patients with Inflammatory Cardiomyopathy

INTRODUCTION

Inflammatory cardiomyopathy (ICM) frequently leads to myocardial fibrosis, resulting in permanent deterioration of the left ventricular function and an unfavorable outcome. Soluble suppression of tumorigenicity 2 receptor (sST2) is a novel marker of inflammation and fibrosis in cardiovascular tissues. sST2 was found to be helpful in predicting adverse outcomes in heart failure patients with reduced ejection fraction. The aim of this study was to determine the association of sST2 plasma levels with cardiac magnetic resonance (CMR) and echocardiography imaging features of left ventricular impairment in ICM patients, as well as to evaluate the applicability of sST2 as a prognosticator of the clinical status in patients suffering from ICM.

METHODS

We used plasma samples of 89 patients presenting to the Heart Center Leipzig with clinically suspected myocardial inflammation. According to immunohistochemical findings in endomyocardial biopsies (EMB) conducted in the context of patients' diagnostic work-up, inflammatory cardiomyopathy was diagnosed in 60 patients (ICM group), and dilated cardiomyopathy in 29 patients (DCM group). All patients underwent cardiac catheterization for exclusion of coronary artery disease and CMR imaging on 1.5 or 3 Tesla. sST2 plasma concentration was determined using ELISA.

RESULTS

Mean plasma concentration of sST2 in the whole patient cohort was 45.8 ± 26.4 ng/mL (IQR 27.5 ng/mL). In both study groups, patients within the highest quartile of sST2 plasma concentration had a significantly lower left ventricular ejection fraction (LV-EF) compared to patients within the lowest sST2 plasma concentration quartile (26 ± 11% vs. 40 ± 13%, p = 0.05 for ICM and 24 ± 13% vs. 51 ± 10%, p = 0.004 for DCM). sST2 predicted New York Heart Association (NYHA) class III/IV at 12 months follow-up more efficiently in ICM compared to DCM patients (AUC 0.85 vs. 0.61, p = 0.02) and was in these terms superior to NT-proBNP and cardiac troponin T. ICM patients with sST2 plasma concentration higher than 44 ng/mL at baseline had a significantly higher probability of being assigned to NYHA class III/IV at 12 months follow-up (hazard ratio 2.8, 95% confidence interval 1.01-7.6, log rank p = 0.05).

CONCLUSION

Plasma sST2 levels in ICM patients reflect the degree of LV functional impairment at hospital admission and predict functional NYHA class at mid-term follow-up. Hence, ST2 may be helpful in the evaluation of disease severity and in the prediction of the clinical status in ICM patients.

Heart failure with preserved left ventricular ejection fraction in patients with obstructive sleep apnea syndrome: prognostic value of biomarkers

Aim      To study the role of soluble ST2 (sST2), N-terminal pro-brain natriuretic peptide (NT-proBNP), and С-reactive protein (CRP) in patients with chronic heart failure and preserved left ventricular ejection fraction (CHF with pLVEF) and syndrome of obstructive sleep apnea (SOSA) in stratification of the risk for development of cardiovascular complications (CVC) during one month of a prospective observation.Material and methods  The study included 71 men with SOSA with an apnea/hypopnea index (AHI) &gt;15 per hour, abdominal obesity, and arterial hypertension. Polysomnographic study and echocardiography according to a standard protocol with additional evaluation of left ventricular myocardial fractional changes and work index were performed for all patients at baseline and after 12 months of observation. Serum concentrations of sST2 , NT-proBNP, and CRP were measured at baseline by enzyme-linked immunoassay (ELISA).Results The ROC analysis showed that the cutoff point characterizing the development of CVC were sST2 concentrations ≥29.67 ng/l (area under the curve, AUC, 0.773, sensitivity 65.71 %, specificity 86.11 %; p&lt;0.0001) while concentrations of NT-proBNP (AUC 0.619; p=0.081) and CRP (AUC 0.511; р=0.869) were not prognostic markers for the risk of CVC. According to data of the ROC analysis, all patients were divided into 2 groups based on the sST2 cutoff point: group 1 included 29 patients with ST2 ≥29.67 ng/l and group 2 included 42 patients with ST2 &lt;29.67 ng/l. The Kaplan-Meyer analysis showed that the incidence of CVC was higher in group 1 than in group 2 (79.3 and 28.6 %, respectively, p&lt;0.001). The regression analysis showed that adding values of AHI and left ventricular myocardial mass index (LVMMI) to sST2 in the model increased the analysis predictive significance.Conclusion      Measuring sST2 concentration may be used as a noninvasive marker for assessment of the risk of CVC development in patients with CHF with pLVEF and SOSA within 12 months of observation. Adding AHI and LVMMI values to the model increases the predictive significance of the analysis.

Role of the IL-33/ST2 axis in cardiovascular disease: A systematic review and meta-analysis

Interleukin (IL)-33 and its unique receptor, ST2, play a pivotal role in the immune response to infection and stress. However, there have been conflicting reports of the role of IL-33 in cardiovascular disease (CVD) and the potential of this axis in differentiating CVD patients and controls and with CVD disease severity, remains unclear.

AIMS

1) To quantify differences in circulating IL-33 and/or sST2 levels between CVD patients versus controls. 2) Determine association of these biomarkers with mortality in CVD and community cohorts.

METHODS AND RESULTS

Using Pubmed/MEDLINE, Web of Science, Prospero and Cochrane databases, systematic review of studies published on IL-33 and/or sST2 levels in patients with CVD (heart failure, acute coronary syndrome, atrial fibrillation, stroke, coronary artery disease and hypertension) vs controls, and in cohorts of each CVD subtype was performed. Pooled standardised mean difference (SMD) of biomarker levels between CVD-cases versus controls and hazard ratios (HRs) for risk of mortality during follow-up in CVD patients, were assessed by random effects meta-analyses. Heterogeneity was evaluated with random-effects meta-regressions. From 1071 studies screened, 77 were meta-analysed. IL-33 levels were lower in HF and CAD patients vs controls, however levels were higher in stroke patients compared controls [Meta-SMD 1.455, 95% CI 0.372-2.537; p = 0.008, I2 = 97.645]. Soluble ST2 had a stronger association with risk of all-cause mortality in ACS (Meta-multivariate HR 2.207, 95% CI 1.160-4.198; p = 0.016, I2 = 95.661) than risk of all-cause mortality in HF (Meta-multivariate HR 1.425, 95% CI 1.268-1.601; p<0.0001, I2 = 92.276). There were insufficient data to examine the association of IL-33 with clinical outcomes in CVD.

CONCLUSIONS

IL-33 and sST2 levels differ between CVD patients and controls. Higher levels of sST2 are associated with increased mortality in individuals with CVD. Further study of IL-33/ST2 in cardiovascular studies is essential to progress diagnostic and therapeutic advances related to IL-33/ST2 signalling.

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

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

Increased Serum Levels of soluble ST2 as a Predictor of Disease Progression in Systemic Sclerosis

OBJECTIVE

Interleukin-33 (IL-33) has been investigated as a mediator in the pathogenesis of fibrosis in lung, liver, and heart. There is accumulating evidence for the involvement of the IL-33/IL-33 receptor ST2L signalling pathway in systemic sclerosis (SSc). Little is known about the role of serum sST2 in SSc, which is the subject of the present investigation.

METHOD

Serum levels of sST2 were measured in 49 patients with SSc, recruited prospectively between November 2017 and March 2019. Patients were divided into those with progressive and those with stable disease. Receiver operating characteristics (ROC) curve analysis was applied to study sST2 as a marker for identifying patients with progressive disease. We used multivariate logistic regression analysis to evaluate the predictive value of sST2 for progressive disease after adjustment for potential confounding factors.

RESULTS

Serum sST2 levels in patients with progressive disease were significantly elevated compared with patients with stable disease (mean ± sem: 50.4 ± 4.7 ng/mL vs 29.2 ± 2.97 ng/mL, p < 0.001). ROC curve analysis identified an sST2 cut-off value of 37.8 ng/mL as optimal for discriminating patients with progressive disease from those with stable disease (sensitivity 80.0%, specificity 79.3%, area under the curve 0.80). After controlling for potential confounding factors (age, gender, C-reactive protein, pro-brain natriuretic peptide, and sum of internal medicine comorbidities), sST2 remained predictive of progressive disease (odds ratio 1.070, 95% confidence interval 1.017-1.126, p < 0.009).

CONCLUSION

In the present study, sST2 serum levels were predictive of disease progression in patients with SSc.