Using ST2 in cardiovascular patients: a review

Cardiorenal syndrome: clinical diagnosis, molecular mechanisms and therapeutic strategies

As the heart and kidneys are closely connected by the circulatory system, primary dysfunction of either organ usually leads to secondary dysfunction or damage to the other organ. These interactions play a major role in the pathogenesis of a clinical entity named cardiorenal syndrome (CRS). The pathophysiology of CRS is complicated and involves multiple body systems. In early studies, CRS was classified into five subtypes according to the organs associated with the vicious cycle and the acuteness and chronicity of CRS. Increasing evidence shows that CRS is associated with a variety of pathological mechanisms, such as haemodynamics, neurohormonal changes, hypervolemia, hypertension, hyperuraemia and hyperuricaemia. In this review, we summarize the classification and currently available diagnostic biomarkers of CRS. We highlight the recently revealed molecular pathogenesis of CRS, such as oxidative stress and inflammation, hyperactive renin‒angiotensin‒aldosterone system, maladaptive Wnt/β-catenin signalling pathway and profibrotic TGF‒β1/Smad signalling pathway, as well as other pathogeneses, such as dysbiosis of the gut microbiota and dysregulation of noncoding RNAs. Targeting these CRS-associated signalling pathways has new therapeutic potential for treating CRS. In addition, various chemical drugs, natural products, complementary therapies, blockers, and agonists that protect against CRS are summarized. Since the molecular mechanisms of CRS remain to be elucidated, no single intervention has been shown to be effective in treating CRS. Pharmacologic therapies designed to block CRS are urgently needed. This review presents a critical therapeutic avenue for targeting CRS and concurrently illuminates challenges and opportunities for discovering novel treatment strategies for CRS.

Prognostic value of sst2 in long-term mortality in acute heart failure

BACKGROUND

The use of biochemical markers in ADHF is considered valuable both in the diagnosis and treatment of diseases and in follow-up. This study aimed to investigate the prognostic power of serum sST2 and NT-proBNP levels in predicting long-term mortality in patients with ADHF using serial measurement.

METHODS

A total of 122 patients with ADHF were included in this prospective study. Venous blood samples were taken from the patients at the time of first admission to the emergency department and 48 h after hospitalisation. Serial measurements were performed using the same blood samples to determine NT-proBNP and sST2 levels.

RESULTS

The 1st time sST2 value was found to be significantly higher in the deceased group than in the living group, and this increase was found to be statistically significant (p < 0.001). The cut-off value for the 1st time value of sST2 was > 56.79 ng/mL, with 91.2% sensitivity and 79.5% specificity (area under the curve (AUC): 0.902, 95% confidence interval (CI): 0.835-0.948, p < 0.001). The cut-off value for the 2nd time sST2 value was > 38.91 ng/mL, with 97.1% sensitivity and 81.8% specificity (AUC: 0.932, 95% CI: 0.872-0.970, p < 0.001).

CONCLUSION

In our study, sST2 gained value as a marker that should be included in panels with multiple markers. It seems more appropriate to recommend the serial measurement of sST2 in heart failure.

LIMITATIONS OF OUR STUDY

The sample size is relatively small and there is no standard in timing and numbers in serial measurements.

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.

Blood biomarkers to detect functional impairment in adult patients with repaired tetralogy of Fallot

Background

The relationship between plasma brain natriuretic peptide (NT-proBNP) and soluble suppression of tumorigenicity-2 (sST2) with structural adaptions and exercise capacity remains incompletely described in patients with repaired Tetralogy of Fallot (rTOF).

Methods

Peripheral venous blood samples were drawn for 99 patients with repaired TOF, 59 patients with severe pulmonary regurgitation (PR) and 40 patients with no or mild PR. NT-proBNP was measured using enzyme-linked immunosorbent assays (Roche Diagnostics, Indianapolis, IN). Soluble ST2 levels were assessed on Aspect-plus ST2 quantitative rapid test.

Results

The mean value of NT-proBNP was 160 ± 137 pg/ml, and sST2 was 29 ± 13, ng/ml in the entire population. 58 % had an elevated NT-proBNP, while sST2 was abnormal in 40 %. Mean NT-proBNP was significantly higher in patients with severe PR (169 ± 150 vs145 ± 118, pg/ml, p < 0.001), while similar sST2 levels were observed in both groups (29 ± 14 vs30 ± 12, ng/ml, p > 0.05). NT-proBNP and sST2 levels were higher in patients with transannular patch when compared to other RVOT intervention (174 ± 145 vs 107 ± 100, pg/ml, p < 0.001); (31 ± 13 vs 29 ± 15, ng/ml, p < 0.05). Both biomarkers were significantly associated with exercise capacity, but NT-proBNP (r = -0.60, p < 0.001) was stronger. The optimal cut-off of 90 pg/ml for NT-proBNP had a sensitivity of 74 % and specificity of 63 % for detection of impaired exercise capacity.

Conclusions

Serum levels of sST2 and NT-proBNP are elevated in patients with repaired TOF, with higher values observed in those with severe PR, but also in patients undergoing transannular patch repair. Incorporating both markers in these patients increased the ability to detect impairment in exercise capacity.

Biomarkers and optical based biosensors in cardiac disease detection: early and accurate diagnosis

Rapid and precise detection methods for the early-stage detection of cardiovascular irregularities are crucial to stopping and reducing their development. Cardiovascular diseases (CVDs) are the leading cause of death in the world. Hence, cardiac-related biomarkers are essential for monitoring and managing of process. The necessity for biomarker detection has significantly widened the field of biosensor development. Bio-sensing methods offer rapid detection, low cost, sensitivity, portability, and selectivity in the development of devices for biomarker detection. For the prediction of cardiovascular diseases, some biomarkers can be used, like C-reactive protein (CRP), troponin I or T, creatine kinase (CK-MB), B-type natriuretic peptide (BNP), myoglobin (Mb), suppression of tumorigenicity 2 protein (ST2) and galectin-3 (Gal3). In this review, recent research studies were covered for gaining insight into utilizing optical-based biosensors, including surface plasmon resonance (SPR), photonic crystals (PCs), fluorescence-based techniques, fiber optics, and also Raman spectroscopy biosensors for the ultrasensitive detection of cardiac biomarkers. The main goal of this review is to focus on the improvement of optical biosensors in the future for the diagnosis of heart diseases and to discuss how to enhance their properties for use in medicine. Some main data from each study reviewed are emphasized, including the CVD biomarkers and the response range of the optical-based devices and biosensors.

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

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

New Insight in Cardiorenal Syndrome: From Biomarkers to Therapy

Cardiorenal syndrome consists in the coexistence of acute or chronic dysfunction of heart and kidneys resulting in a cascade of feedback mechanisms and causing damage to both organs associated with high morbidity and mortality. In the last few years, different biomarkers have been investigated with the aim to achieve an early and accurate diagnosis of cardiorenal syndrome, to provide a prognostic role and to guide the development of targeted pharmacological and non-pharmacological therapies. In such a context, sodium-glucose cotransporter 2 (SGLT2) inhibitors, recommended as the first-line choice in the management of heart failure, might represent a promising strategy in the management of cardiorenal syndrome due to their efficacy in reducing both cardiac and renal outcomes. In this review, we will discuss the current knowledge on the pathophysiology of cardiorenal syndrome in adults, as well as the utility of biomarkers in cardiac and kidney dysfunction and potential insights into novel therapeutics.

Soluble ST2 as a New Oxidative Stress and Inflammation Marker in Metabolic Syndrome

BACKGROUND

Metabolic syndrome (MS) is a complex and prevalent disorder. Oxidative stress and inflammation might contribute to the progression of MS. Soluble ST2 (sST2) is an attractive and druggable molecule that sits at the interface between inflammation, oxidative stress and fibrosis. This study aims to analyze the relationship among sST2, oxidative stress, inflammation and echocardiographic parameters in MS patients.

METHODS

Fifty-eight patients with MS were recruited and underwent physical, laboratory and transthoracic echocardiography examinations. Commercial ELISA and appropriate colorimetric assays were used to quantify serum levels of oxidative stress and inflammation markers and sST2.

RESULTS

Circulating sST2 was increased in MS patients and was significantly correlated with the oxidative stress markers nitrotyrosine and 8-hydroxy-2'-deoxyguanosine as well as with peroxide levels. The inflammatory parameters interleukin-6, intercellular adhesion molecule-1 and myeloperoxidase were positively correlated with sST2. Noteworthy, sST2 was positively correlated with left ventricular mass, filling pressures and pulmonary arterial pressures.

CONCLUSION

Circulating levels of sST2 are associated with oxidative stress and inflammation burden and may underlie the pathological remodeling and dysfunction of the heart in MS patients. Our results suggest that sST2 elevation precedes diastolic dysfunction, emerging as an attractive biotarget in MS.

Prognostic value of soluble ST2, high-sensitivity cardiac troponin, and NT-proBNP in type 2 diabetes: a 15-year retrospective study

Background

Patients with type 2 diabetes (T2DM) present an increased risk of cardiovascular (CV) disease and excess CV-related mortality. Beyond the established role of brain natriuretic peptide (BNP) and cardiac troponins (cTn), other non-cardiac-specific biomarkers are emerging as predictors of CV outcomes in T2DM.

Methods

Serum levels of soluble suppression of tumorigenesis 2 (sST2), high-sensitivity (hs)-cTnI, and N-terminal (NT)-proBNP were assessed in 568 patients with T2DM and 115 healthy controls (CTR). Their association with all-cause mortality and the development of diabetic complications was tested in T2DM patients over a median follow-up of 16.8 years using Cox models and logistic regressions.

Results

sST2 followed an increasing trend from CTR to uncomplicated T2DM patients (T2DM-NC) to patients with at least one complication (T2DM-C), while hs-cTnI was significantly higher in T2DM-C compared to CTR but not to T2DM-NC. A graded association was found between sST2 (HR 2.76 [95% CI 1.20–6.33] for ≥ 32.0 ng/mL and 2.00 [1.02–3.94] for 16.5–32.0 ng/mL compared to < 16.5 ng/mL, C-statistic = 0.729), NT-proBNP (HR 2.04 [1.90–4.55] for ≥ 337 ng/L and 1.48 [1.05–2.10] for 89–337 ng/L compared to < 89 ng/L, C-statistic = 0.741), and 15-year mortality in T2DM, whereas increased mortality was observed in patients with hs-cTnI ≥ 7.8 ng/L (HR 1.63 [1.01–2.62]). A ‘cardiac score’ based on the combination of sST2, hs-cTnI, and NT-proBNP was significantly associated with all-cause mortality (HR 1.35 [1.19–1.53], C-statistic = 0.739) and development of CV events.

Conclusions

sST2, hs-cTnI, and NT-proBNP are associated with 15-year mortality and onset of CV events in T2DM. The long-term prognostic value of sST2 and its ability to track variables related to insulin resistance and associated metabolic disorders support its implementation into routine clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01616-3.

IL-33/ST2 pathway as upper-hand of inflammation in allergic asthma contributes as predictive biomarker in heart failure

Allergic asthma is an inflammatory disorder of the bronchi, and as a major health problem, more than 350 million people suffer from asthma in the world. Many cardiovascular disorders resulted in the impairment of the heart's power to pump blood that leads to the HF. More than 25 million people worldwide live with HF. Accordingly, identifying the biomarkers to predict the onset of future asthma and HF is necessary. IL-33 is an inflammatory cytokine that has the main role in pathophysiology of asthma and HF. Also, in IL-33 receptor, the ST2 is involved in cardiac fibrosis and remodelling in HF and pathogenesis of allergic asthma. Increased sST2 in allergic asthma helps to control inflammation during asthma, but increased sST2 in HF is a predictable biomarker to present risk factor of HF during the time of the patients.

IL-33 and Soluble ST2 Are Associated With Recurrent Spontaneous Abortion in Early Pregnancy

Normal pregnancy is related to the successful transition from type 1 cellular immunity to type 2 cellular immunity. Therefore, this study aimed to investigate whether there is abnormal expression of cytokines in the process of inducing Recurrent spontaneous abortion (RSA). Interleukin (IL)-33 is a new member of the IL-1 family, and ST2, as IL-33’s receptor, induced the production of type 2 cytokines. In this study, blood samples were collected from 19 non-pregnant women of normal childbearing age, 28 normal pregnant women, and 33 women with RSA. The serum concentrations of IL-33 and ST2 were detected by flow cytometry. Our results showed that the serum concentrations of IL-33 and ST2 in the RSA group were significantly higher than those in the healthy control group (IL-33: P < 0.05; ST2: P < 0.0001), and IL-33 and ST2 had a higher level in the process of RSA predictive value. In addition, this study initially found that the serum concentrations of IL-33 and ST2 were not significantly correlated with the number of weeks of pregnancy, and there was a lower correlation between IL-33 and ST2 during RSA. This result may be related to the small number of cases. This study is the first time to correlate the changes in serum concentrations of IL-33 and ST2 with RSA, which may be a novel biomarker for the prediction and treatment of RSA.

Differences in maternal soluble ST2 levels in the third trimester of normal pregnancy versus preeclampsia

BACKGROUND

Preeclampsia is associated with intense inflammatory response in pregnancy, and soluble ST2 (sST2) is pathologically increased in this condition. No data exist regarding maternal sST2 levels in normal pregnancy versus preeclampsia in areas of southeast Asia with an ethnic Malay predominance.

MATERIALS AND METHODS

Patients were sorted into normal pregnancy or preeclampsia. Patients with a history of allergic, inflammatory, or malignant disease were excluded. One sample was taken per patient; all samples were taken during the third trimester of pregnancy. Thirty samples from each group were enrolled in the study, totaling 60 samples. Soluble ST2 levels in maternal plasma were measured using the Presage® ST2 Assay according to manufacturer instructions, and data was analyzed using SPSS 23.

RESULTS

Patients in the preeclampsia group were significantly older than those in the normal pregnancy group (p = 0.01). Most patients with preeclampsia presented as early-onset (n = 23). Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly higher (p < 0.001) in the preeclampsia group. Mean sST2 level in the preeclampsia group (85.89 ng/ml) was significantly higher than the normal pregnancy group mean (38.3 ng/ml) during the third trimester (p < 0.001). This study also found a correlation between sST2 and preeclampsia (p < 0.001, r = 0.480), SBP (p < 0.001, r = 0.407), and DBP (p = 0.007, r = 0.342), while preeclampsia was found to be the best explanatory variable of sST2 levels (r = 0.468, p < 0.001). sST2 level> 63.66 ng/ml has sensitivity 50% and specificity 93.3%, with AUC of 0.78 [95% CI 0.66 - 0.90], p < 0.001. The sST2 > 63.66 ng/ml has an OR of 14.0 [95% CI 2.82 - 69.6], p < 0.001 for preeclampsia. The dose-response relationship between sST2 level and preeclampsia was linear.

CONCLUSION

Soluble ST2 levels were increased in both normal pregnancy and preeclampsia but were significantly higher in patients with preeclampsia. Preeclampsia was also found to be the best explanatory variable for the increase of sST2 levels in ethnic Malay predominance.

Gender-Related Differences in Heart Failure Biomarkers

Important differences in comorbidities and clinical characteristics exist between women and men with heart failure (HF). In particular, differences in the kinetics of biological circulating biomarkers—a critical component of cardiovascular care—are highly relevant. Most circulating HF biomarkers are assessed daily by clinicians without taking sex into account, despite the multiple gender-related differences observed in plasma concentrations. Even in health, compared to men, women tend to exhibit higher levels of natriuretic peptides and galectin-3 and lower levels of cardiac troponins and the cardiac stress marker, soluble ST2. Many biological factors can provide a reliable explanation for these differences, like body composition, fat distribution, or menopausal status. Notwithstanding, these sex-specific differences in biomarker levels do not reflect different pathobiological mechanisms in HF between women and men, and they do not necessarily imply a need to use different diagnostic cut-off levels in clinical practice. To date, the sex-specific prognostic value of HF biomarkers for risk stratification is an unresolved issue that future research must elucidate. This review outlines current evidence regarding gender-related differences in circulating biomarkers widely used in HF, the pathophysiological mechanisms underlying these differences, and their clinical relevance.

Interleukin-36 Cytokine/Receptor Signaling: A New Target for Tissue Fibrosis

Tissue fibrosis is a major unresolved medical problem, which impairs the function of various systems. The molecular mechanisms involved are poorly understood, which hinders the development of effective therapeutic strategies. Emerging evidence from recent studies indicates that interleukin 36 (IL-36) and the corresponding receptor (IL-36R), a newly-characterized cytokine/receptor signaling complex involved in immune-inflammation, play an important role in the pathogenesis of fibrosis in multiple tissues. This review focuses on recent experimental findings, which implicate IL-36R and its associated cytokines in different forms of organ fibrosis. Specifically, it outlines the molecular basis and biological function of IL-36R in normal cells and sums up the pathological role in the development of fibrosis in the lung, kidney, heart, intestine, and pancreas. We also summarize the new progress in the IL-36/IL-36R-related mechanisms involved in tissue fibrosis and enclose the potential of IL-36R inhibition as a therapeutic strategy to combat pro-fibrotic pathologies. Given its high association with disease, gaining new insight into the immuno-mechanisms that contribute to tissue fibrosis could have a significant impact on human health.

The evolving systemic biomarker milieu in obese ZSF1 rat model of human cardiometabolic syndrome: Characterization of the model and cardioprotective effect of GDF15

Cardiometabolic syndrome has become a global health issue. Heart failure is a common comorbidity of cardiometabolic syndrome. Successful drug development to prevent cardiometabolic syndrome and associated comorbidities requires preclinical models predictive of human conditions. To characterize the heart failure component of cardiometabolic syndrome, cardiometabolic, metabolic, and renal biomarkers were evaluated in lean and obese ZSF1 19- to 32-week-old male rats. Histopathological assessment of kidneys and hearts was performed. Cardiac function, exercise capacity, and left ventricular gene expression were also analyzed. Obese ZSF1 rats exhibited multiple features of human cardiometabolic syndrome by pathological changes in systemic renal, metabolic, and cardiovascular disease circulating biomarkers. Hemodynamic assessment, echocardiography, and decreased exercise capacity confirmed heart failure with preserved ejection fraction. RNA-seq results demonstrated changes in left ventricular gene expression associated with fatty acid and branched chain amino acid metabolism, cardiomyopathy, cardiac hypertrophy, and heart failure. Twelve weeks of growth differentiation factor 15 (GDF15) treatment significantly decreased body weight, food intake, blood glucose, and triglycerides and improved exercise capacity in obese ZSF1 males. Systemic cardiovascular injury markers were significantly lower in GDF15-treated obese ZSF1 rats. Obese ZSF1 male rats represent a preclinical model for human cardiometabolic syndrome with established heart failure with preserved ejection fraction. GDF15 treatment mediated dietary response and demonstrated a cardioprotective effect in obese ZSF1 rats.

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

Aims

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

Methods and results

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

Conclusions

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

Prognostic value of soluble ST2 and soluble LR11 on mortality and cardiovascular events in peritoneal dialysis patients

Background

Although the soluble form of suppression of tumorigenicity 2 (sST2) and soluble low-density lipoprotein receptor relative with 11 ligand-binding repeats (sLR11) have emerged as novel cardiovascular biomarkers in patients with cardiovascular disease, their prognostic value has not been fully investigated in peritoneal dialysis (PD) patients.

Methods

We included 74 prevalent PD patients from a prospective cohort and measured serum sST2 and sLR11 concentrations by an enzyme-linked immunosorbent assay. The association of these biomarkers and all-cause mortality and major adverse cardiac and cerebrovascular events (MACCEs) was evaluated.

Results

During a follow-up of 38.5 months, all-cause deaths and MACCEs were observed in 13 (17.6%) patients and 23 (31.3%) patients. Multivariable Cox analyses demonstrated that greater sST2 was independently associated with higher risk of all-cause mortality (≥75.8 ng/mL; hazard ratio [HR] = 5.551; 95% confidence interval [CI] = 1.360–22.660) and MACCEs (≥72.5 ng/mL; HR = 4.609; 95% CI = 1.608–13.208). Furthermore, sST2 showed additive predictive value for mortality to the base model including traditional risk factors (net reclassification index = 0.598, P = 0.04). sLR11 was not significantly associated with all-cause mortality or MACCE.

Conclusions

sST2, but not sLR11, indicated a significant prognostic value for all-cause mortality and cardiovascular events in PD patients. Further research is needed to validate emerging biomarkers in these populations.

Soluble ST2: A complex and diverse role in several diseases

The Suppression of Tumorigenicity 2 protein (ST2) is a member of the interleukin (IL) 1 receptor family with transmembrane (ST2L) and soluble (sST2) isoforms that are (over)expressed in several cells in different conditions and following various triggers (e.g. inflammation, stress). The ligand of ST2 is IL-33, which on binding to ST2L results in nuclear signalling and immunomodulatory action in various cells (tumour, immune, heart). sST2, that is released in the circulation, functions as a »decoy« receptor of IL-33 and inhibits IL-33/ST2L signalling and beneficial effects. The importance and role of the ST2/IL-33 axis and sST2 have been evaluated and confirmed in several inflammatory, cancer and cardiac diseases. sST2 is involved in homeostasis/pathogenesis of these diseases, as the counterbalance/response on IL-33/ST2L axis activation, which is triggered and expressed during developing fibrosis, tissue damage/inflammation and remodelling. In clinical studies, sST2 has been recognised as an important prognostic marker in patients with cardiac disease, including patients with chronic kidney disease where specific characteristics of sST2 enable better assessment of the risk of End-Stage Renal Disease patients on dialysis. sST2 is also recognised as an important marker for monitoring treatment in heart failure patients. However, accurate measurement and interpretation of ST2 concentration in serum/plasma samples for routine and research applications require the use of appropriate methods and recognition of essential characteristics of both the methods and the analyte that may influence the result. sST2, as one of the most promising disease biomarkers, is deserving of further study and wider application in clinical practice.

Biomarker developments in heart failure: 2016 and beyond

PURPOSE OF REVIEW

Biomarkers play a fundamental role in the management of heart failure. Both new and old biomarkers are evaluated every year with new information gained for their use in heart failure. Major advancements have been made in the past 2 years in key biomarkers that will surely become part of standard clinical management of heart failure. This review will focus on major developments since 2016.

RECENT FINDINGS

Soluble suppression of tumorigenicity 2 has had multiple breakthrough studies solidifying its prognostic use in both acute and chronic heart failure and with multiple studies showing a strong benefit with serial monitoring. High-sensitivity troponin has also recently been demonstrated to be a powerful prognostic biomarker in heart failure. Additionally, it may serve as a novel screening tool to identify patients at high risk for incident heart failure. Natriuretic peptides continue to show their resilience as the main prognostic biomarker in heart failure. Recent studies suggest natriuretic peptides may help identify certain patient populations that benefit from specific therapies and they can predict prognosis beyond in diseases other than heart failure.

SUMMARY

Although natriuretic peptides are well-established biomarkers in heart failure, the weight of evidence for soluble suppression of tumorigenicity 2 and high-sensitivity troponin has significantly grown since 2016 that these two biomarkers should be incorporated into regular practice and management of heart failure patients.

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.

Association of soluble ST2 with all-cause and cardiovascular mortality in renal transplant recipients: a single-centre cohort study

BACKGROUND

Soluble ST2 is a novel biomarker of myocardial fibrosis with an established role in prognostication of patients with heart failure. Its role in cardiovascular risk prediction for renal transplant recipients has not been investigated despite promising results for ST2 in other populations with renal disease.

METHODS

In this prospective cohort study, 367 renal transplant recipients were followed up for a median of 16.2 years to investigate the association of soluble ST2 concentration with all-cause mortality. Cardiovascular mortality and major adverse cardiovascular events were secondary outcomes. Cox regression models were used to calculate hazard ratios and 95% confidence intervals for ST2 before and after adjustments. ST2 concentration was analysed both as a continuous variable and following categorisation according to the recommended cut-point of 35 ng/ml.

RESULTS

A twofold higher ST2 concentration was associated with a 36% increased risk of all-cause mortality after adjustment for conventional cardiovascular risk factors and high-sensitivity C-reactive protein (adjusted hazard ratio 1.36; 95% confidence interval 1.06-1.75; p = 0.016). Associations with ST2 concentration were similar for cardiovascular events (adjusted hazard ratio 1.31; 95% confidence interval 1.00-1.73; p = 0.054), but were stronger for cardiovascular mortality (adjusted hazard ratio 1.61; 95% confidence interval 1.07-2.41; p = 0.022). Addition of ST2 to risk prediction models for mortality and cardiovascular events failed to improve their predictive accuracy.

CONCLUSIONS

ST2 is associated with, but does not improve prediction of, adverse outcomes in renal transplant recipients.

Biomarkers and Donor Selection in Heart Transplantation

BACKGROUND

Previously, we showed that B-type natriuretic peptide (BNP) measured in the donor was related to cardiac performance after cardiac transplantation. The present study assesses the value of 3 biomarkers in the selection of donor hearts in a larger cohort.

METHODS

Blood samples were prospectively obtained in 105 brain-dead patients scheduled for heart donation. BNP, soluble suppressor of tumorigenicity 2 (ST2), and troponin of heart donors were correlated with hemodynamic parameters early after transplantation as well as with the mortality of the recipients.

RESULTS

A significant inverse relationship was found between donor BNP measured at the time of donation and recipient cardiac index and cardiac output at day 13 post-transplantation (r = -0.31, P = .005, and r = -0.34, P = .0016, respectively). Logistic regression analysis-including BNP, ST2, and troponin-showed that donor BNP was a predictor of a poor cardiac index (< 2.2 L/min/m²) in the recipient (P = .04). A donor BNP > 132 pg/mL has a sensitivity of 56% (95% confidence interval 21-86) and a specificity of 86% (95% confidence interval 77-93) to predict poor cardiac performance in the recipient. When the donor BNP is ≤ 132 pg/mL, the risk of a poor cardiac function in the recipient is very low (negative predictive value 94%). Mortality at 30 days was also correlated to donor BNP (r = 0.29, P = .0029). Long-term survival of the recipient was not correlated to the biomarkers measured in the donor.

CONCLUSION

Donor BNP, but not donor ST2 or high-sensitivity troponin, provides information on the donor heart and early post-transplant performance, including 1-month mortality.

Mechanisms of cardiac collagen deposition in experimental models and human disease

The inappropriate deposition of extracellular matrix within the heart (termed cardiac fibrosis) is associated with nearly all types of heart disease, including ischemic, hypertensive, diabetic, and valvular. This alteration in the composition of the myocardium can physically limit cardiomyocyte contractility and relaxation, impede electrical conductivity, and hamper regional nutrient diffusion. Fibrosis can be grossly divided into 2 types, namely reparative (where collagen deposition replaces damaged myocardium) and reactive (where typically diffuse collagen deposition occurs without myocardial damage). Despite the widespread association of fibrosis with heart disease and general understanding of its negative impact on heart physiology, it is still not clear when collagen deposition becomes pathologic and translates into disease symptoms. In this review, we have summarized the current knowledge of cardiac fibrosis in human patients and experimental animal models, discussing the mechanisms that have been deduced from the latter in relation to the former. Because assessment of the extent of fibrosis is paramount both as a research tool to further understanding and as a clinical tool to assess patients, we have also summarized the current state of noninvasive/minimally invasive detection systems for cardiac fibrosis. Albeit not exhaustive, our aim is to provide an overview of the current understanding of cardiac fibrosis, both clinically and experimentally.

Mean velocity of the pulmonary artery estimated by cardiac magnetic resonance as an early prognostic predictor in heart failure

BACKGROUND AND OBJECTIVE

To identify early, non-invasive prognostic indicators in heart failure (HF), with and without associated pulmonary hypertension, by means of cardiac magnetic resonance, and oxidative stress and anti-inflammatory biomarkers such as Trolox^TM (antioxidant status) and IL-10 (anti-inflammatory cytokine).

PATIENTS AND METHODS

We prospectively included 70 patients admitted for new-onset HF. During index admission, mean velocity of the pulmonary artery (mvPA) was measured, and blood Trolox^TM and IL-10 determined. The study sample was divided in two groups according to the optimal cut-off value for event prediction calculated by the ROC curve (mvPA=8cm/s), considering HF-readmission and all-cause mortality as the primary combined event.

RESULTS

During a median follow-up of 290 days, 16 events occurred. In patients with preserved right ventricular (RV) function, mvPA ≤8cm/s was associated with a higher incidence of events during follow-up, Kaplan-Meier survival analysis (log rank 6.01, p=.014). MvPA did not add prognostic value when RV dysfunction was already established. Trolox^TM concentration was lower in patients with mvPA ≤8cm/s. Higher IL-10 expression was associated with a lower incidence of cardiovascular events during follow-up.

CONCLUSION

In HF patients, mvPA ≤8cm/s predicts a higher rate of cardiovascular events. Specifically, mvPA identifies a higher risk population among patients with preserved RV function, thus confirming its role as an early prognostic indicator. Lower Trolox^TM concentration in the worse prognosis group concurs with previous studies on oxidative stress in pulmonary hypertension. Higher IL-10 concentration among patients free of cardiovascular events could be a reflection of its anti-inflammatory and thus protective role in HF.

Biomarkers in Cardiorenal Syndromes

There is a consensus that cardiorenal syndromes (CRS) are defined as the disorders of heart and kidney where acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in another. Patients with CRS have increased hospitalization and mortality rates, and thus their identification is of great implication. Biomarkers are not only predictive in heart failure or renal diseases, but also useful in identifying cardiac dysfunction in renal diseases and renal injury in heart failure. Thus, they may be applied in order to identify patients with CRS and even assess prognosis and guide therapy in these patients. However, studies on biomarkers have just begun in CRS. Future studies are essential to observe current biomarkers and find novel biomarkers in CRS so as to improve diagnosis, therapy, and prognosis of CRS.

A Review of Interleukin-1 in Heart Disease: Where Do We Stand Today?

Cardiovascular diseases are the leading cause of death worldwide. Research in the last two decades has emphasized the inflammatory process as a key component in the pathogenesis of many of them. The Interleukin-1 family is a pivotal element of inflammation and has been well studied as a therapeutic target in various inflammatory states. Recent trials have explored the effect of Interleukin-1 blockade in cardiovascular diseases and initial evidence of the relevance of such treatment in this field of medicine accumulate. This review will describe the role of Interleukin-1 in heart diseases and the potential therapeutic effect of its blockade in such diseases.

ST2 as a novel prognostic marker in end-stage renal disease patients on hemodiafiltration

BACKGROUND

Patients with end-stage renal disease (ESRD) are prone to severe heart failure (HF) and to several life-threatening events. Therefore, the ability to assess disease prognosis and the risk of short-term events or death is of great importance. The role of soluble ST2 (sST2) as a potential new prognostic marker in ESRD patients is not yet known. The aim of our study was to assess the prognostic value of sST2 in ESRD patients on hemodiafiltration (HDF) and compare it with NT-proBNP, an established prognostic marker for HF and renal disease.

METHODS

123 ESRD patients on HDF were prospectively followed up from the date of the sST2/NT-proBNP measurement until their death or maximally up to 829days. Patients were divided into a low sST2 group (<35ng/mL) or a high sST2 group (≥35ng/mL) according to their measured sST2 concentration at the start of the study. Kaplan-Meier survival curves, Cox regression model and ROC analyses were used in statistical analysis.

RESULTS

During follow-up 32 (26.0%) patients died (all cause mortality). Median (IQR) sST2 serum concentrations of survivors and deceased were 26 (24-29) and 36 (28-59) ng/mL, respectively. The Kaplan-Meier survival analysis showed that survival rate of the high sST2 group was statistically significant lower than of the low sST2 group (P<0.01). Cox regression model for sST2, using a dichotomized (cut-off=35ng/mL, hazard ratio (HR) (95%CI)=2.72 (1.50-4.90), P=0.001) and continuous approach with log-transformed values in univariate (HR (95%CI)=17.35 (4.84-62.22), P<0.001) and multivariate analysis (HR (95%CI)=7.19 (1.89-27.38), P=0.004) showed that sST2 alone and in combination with NT-proBNP can predict all cause mortality.

CONCLUSIONS

sST2 has confirmed prognostic value and is independent of renal function and of HDF treatment. It could be useful independent prognostic marker for stratifying ESRD patients on HDF at high risk for life-threatening events, hospitalisation and death, especially in combination with NT-proBNP.

Soluble ST2 does not change cardiovascular risk prediction compared to cardiac troponin T in kidney transplant candidates

BACKGROUND

Solubility of Tumorigenicity 2 (sST2) is a novel biomarker that better stratifies risk of cardiovascular events (CVE) compared to cardiac troponin T(cTnT) in heart failure. We assessed the association of sST2 with the composite outcome of CVE and/or mortality compared to cTnT in kidney transplant candidates.

METHODS

200 kidney transplant candidates between 2010 and 2013 were included. Elevated sST2 was defined as ≥30ng/ml, cTnT≥0.01 ng/ml.

RESULTS

Median age 53 (interquartile range (IQR) 42-61) years, 59.7% male and 82.0% white. 33.5% had history of CVE, 42.5% left ventricular hypertrophy (LVH) and 15.6% positive cardiac stress test. Elevated sST2 correlated with male gender, history of prior-transplants, CVE, positive stress test, LVH, elevated cTnT, anemia, hyperphosphatemia, increased CRP and non-transplanted status. Male gender, history of CVE and LVH were independent determinants of sST2. During 28 months (IQR 25.3-30), 7.5% died, 13.0% developed CVE and 19.0% developed the composite outcome. Elevated sST2 was associated with the composite outcome (hazard ratio = 1.76, CI 1.06-2.73, p = 0.029) on univariate analysis but not after adjusting for age, diabetes and cTnT (p = 0.068). sST2 did not change the risk prediction model for composite outcome after including age, diabetes, prior history of CVE and elevated cTnT.

CONCLUSIONS

Increased sST2 level is significantly associated with variables associated with CVE in kidney transplant candidates. sST2 was associated with increased risk of the composite outcome of CVE and/or death but not independent of cTnT. Larger studies are needed to confirm these findings and determine whether sST2 has added value in CV risk stratification in this cohort of patients.

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

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

Mid-regional pro-adrenomedullin and ST2 in heart failure: Contributions to diagnosis and prognosis

Heart failure has a high prevalence in developed countries. It is a frequent cause of hospital admission and has an important impact on morbidity, mortality and healthcare costs. Biomarkers have been widely studied in heart failure, as they improve diagnosis and prognostic assessment. Natriuretic peptides are already a part of daily clinical practice but several other biomarkers are being studied. This review focuses on mid-regional pro-adrenomedullin (MR-proADM) and ST2. Neither of these biomarkers is useful in the diagnosis of acute heart failure. However, both have considerable short- and long-term prognostic value in patients with acute and with stable chronic heart failure. The utility of these two biomarkers in guiding heart failure treatment is yet to be established. ST2 appears to have some advantages compared to MR-proADM, because it is more closely associated with ventricular remodeling and fibrosis.

Monitoring Acute Myocardial Infarction Complicated with Cardiogenic Shock — from the Emergency Room to Coronary Care Units

Cardiogenic shock remains the leading cause of death in patients hospitalized for acute myocardial infarction, despite many advances encountered in the last years in reperfusion, mechanical, and pharmacological therapies addressed to stabilization of the hemodynamic condition of these critical patients. Such patients require immediate initiation of the most effective therapy, as well as a continuous monitoring in the Coronary Care Unit. Novel biomarkers have been shown to improve diagnosis and risk stratification in patients with cardiogenic shock, and their proper use may be especially important for the identification of the critical condition, leading to prompt therapeutic interventions. The aim of this review was to evaluate the current literature data on complex biomarker assessment and monitoring of patients with acute myocardial infarction complicated with cardiogenic shock in the Coronary Care Unit.

Effects of a cardiac rehabilitation programme on plasma cardiac biomarkers in patients with chronic heart failure

Background Cardiac rehabilitation (CR) improves the symptoms, exercise capacity and quality of life of chronic heart failure (CHF) patients. Its effects on new plasma biomarkers of prognostic importance are unknown. The present study aimed at analysing the effects of a structured CR programme on plasma cardiac biomarkers in a large population of patients with CHF and reduced left ventricular ejection fraction (LVEF). Methods We enrolled 107 consecutive CHF patients with LVEF ≤ 45% in an ambulatory CR programme. Peak VO₂ and plasma levels of Galectin-3, mid-regional proANP (MR-proADM), soluble suppressor of tumorigenicity 2 (sST2) and mid-regional pro-adrenomedullin (MR-proANP) were assessed at inclusion and at the end of CR. Twenty-four unenrolled patients were managed with standard medical care and evaluated over the same period (no-CR group). Results Galectin-3, sST2, MR-proADM and MR-proANP plasma levels decreased after CR, with respective median reductions of 6.3% for Galectin 3 ( p < 0.001), 7.4% for sST2 ( p = 0.036), 6.4% for MR-proADM ( p = 0.001) and 16% for MR-proANP ( p < 0.001). MR-proADM was negatively correlated with peak VO₂ (ρ = -0.529, 95% confidence interval [CI] -0.654 to -0.375, p < 0.001), and so were their relative variations along the course of CR (ρ = -0.357, 95% CI -0.518 to -0.172, p < 0.001). No change occurred in terms of biomarkers in the no-CR group. Conclusions Plasma cardiac biomarkers such as Galectin-3, MR-proADM, sST2 and MR-proANP all decreased after CR in CHF patients, suggesting an overall improvement in the neuro-hormonal profile.

Multi-Biomarker Profiling and Recurrent Hospitalizations in Heart Failure

Background

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

Methods and results

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

Conclusion

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

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

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