Evaluation of the sST2-guided optimization of medical treatments of patients admitted for heart failure, to prevent readmission: Study protocol for a randomized controlled trial

A rapid and quantitative detection method for plasma soluble growth stimulating gene protein 2 based on time resolved fluorescence immunochromatography

Background: plasma soluble growth stimulating gene protein 2 (sST2) is a new generation biomarker in heart failure (HF), which is an independent predictor of adverse outcomes of heart failure. Thus, the establishment of a rapid and sensitive method for detecting sST2 is urgently needed. Methods: lanthanide element Eu³⁺ coated fluorescent nanometer microspheres (Eu³⁺@FMN) can be used as markers to label monoclonal mouse anti-human sST2 antibody ST-01 (ST-01-Eu³⁺@FMN). When the immune sandwich complex formed between the monoclonal mouse anti-human sST2 antibody ST-02 and ST-01-Eu³⁺@FMN on the test band with the appearance of target object sST2, we can detect the fluorescence intensity of Eu³⁺ on the test band and the quality control band using a dry fluorescence analyzer. We calculated the T/C value (T/C = fluorescence intensity of the test band/fluorescence intensity of the quality control band), fitted to the calibration curve, and measured the concentration value of sST2 in the corresponding sample. Results: the best reaction time was 15 min after condition exploration, and the optimal sample volume was 80 μL. The detection sensitivity of the scheme was 2.14 ng mL^-1. The calibration curve of the assay was y = 0.0113x + 0.0033, and the linear range was 5-200 ng mL^-1. No cross reaction was found when the samples contained BNP, NT-proBNP, and galectin-3, indicating a good specificity. The precision was good with a relative deviation < 15%. The coefficient of variation of detection results of low-concentration samples and high-concentration samples was 4.20% and 3.30% respectively in the same batch of strip tests, so the intra-assay CV was set as <10%; when different batches of strips were used for testing, the coefficient of variation of detection results of low-concentration samples and high-concentration samples was 10.06% and 8.38% respectively, so the inter-assay CV was set as <15%. Stability test results showed that the relative deviation of test results at each time node was <15%, indicating good stability of the assay strips. The correlation coefficient between the ST-01-Eu³⁺@FMN based time-resolved fluorescence immunochromatography analysis and sST2 ELISA kit was 0.98. To confirm the usage of our proposed TRF-ICA for clinical samples, it was used to determine the concentration of sST2 in samples obtained from 34 patients with heart insufficiency, acute and chronic heart failure. As a result, we successfully detected a minimal concentration of 5.21 ng mL^-1 and a maximum concentration of 184.26 ng mL^-1 for sST2. Conclusion: this technique provides a rapid, simple and quantitative detection method for sST2 in clinics. It can help clinicians to predict the incidence of adverse events in patients with HF.

Soluble urokinase-type plasminogen activator receptor strongly predicts global mortality in acute heart failure patients: insight from the STADE-HF registry

Background

Whether soluble urokinase-type plasminogen activator receptor (suPAR) could be a valuable prognostic indicator remains uncertain.

Materials & methods

Patients from STADE-HF (Soluble Suppression of Tumorigenesis-2 as a Help for Management of Diagnosis, Evaluation and Management of Heart Failure) were included for analysis.

Results

95 patients were included. The suPAR level of expression was significantly higher in the group of patients who died at one month (7.90 ± 4.35 ng/ml vs 11.94 ± 6.86 ng/ml; p < 0.05) or 1 year (7.28 ± 4.27 ng/ml vs 11.81 ± 4.88 ng/ml; p < 0.01), but there was no significant difference according to the readmission.

Conclusion

High suPAR levels during hospitalization for acute heart failure were highly predictive for the risk of mortality, but not the risk of readmission.

Conception and bicentric validation of the proSCANNED score, a simplified bedside prognostic score for Heart Failure patients

A simple and accurate prognostic tool for Heart Failure (HF) patients is critical to improve follow-up. Different risk scores are accurate but with limited clinical applicability. The current study aims to derive and validate a simple predictive tool for HF prognosis. French outpatients with stable HF of two university hospitals were included in the derivation (N = 134) or in the validation (N = 274) sample and followed up for a median of 23 months. Potential predictors were variables with known association with mortality and easily available. The proSCANNED risk score was derived using a parametric survival model on complete case data; it includes 8 binary variables and its values are 0–8. In the validation sample, the ability of the score to discriminate the 1-year vital status was moderate (AUC = 0.71, IC95% = [0.64–0.71]). However, the stratification of the score in three groups showed a good calibration for patients in the low- and medium-risk risk group. The proSCANNED score is an easy-to-use tool in clinical practice with a good discrimination, stability, and calibration sufficient to improve the medical care of patients. Other follow up studies are necessary to assess score applicability in larger populations, and its impact.

sST2 as a value-added biomarker in heart failure

Soluble suppression of tumorigenicity-2 (sST2) is a biomarker widely investigated during the last few years. Its role has become clear in pathological conditions such as fibrosis and inflammation. From translational research to laboratory medicine, considerable efforts have been made to elucidate the features of sST2 biomarker and to consider its contribution to HF management. In this review, we summarized the results from recent works concerning sST2, and particularly we focused on the interest of sST2 in conditions for which classical biomarkers value interpretation is misleading. Indeed, despite other HF biomarkers, sST2 was proved to be independent from common comorbidities such as renal dysfunction and hypertension. Thus, sST2 showed promise for a combined strategy with natriuretic peptides, mainly for specific categories of patients. Particular attention was paid to findings on sST2 in HF with preserved ejection fraction (HFpEF), a form of HF for which reliable and specific biomarkers are awaited. Finally, a place is reserved to sST2 kinetics from basal to follow up values in order to improve clinical decision making and to customize patient treatments.

ST2 and the ST2/IL-33 signalling pathway-biochemistry and pathophysiology in animal models and humans

ST2 is an interleukin (IL)-1 receptor family member with transmembrane (ST2L) and soluble (sST2) isoforms. Structurally, the ST2 gene products are very similar in mice and humans. In humans and in mice, alternative promoter activation and splicing produce ST2L and sST2. ST2L represents the longest transcript, whereas sST2 is the truncated, soluble isoform. ST2L is the biological receptor for IL-33, a member of the IL-1 family. IL-33 is the functional ligand of ST2L and signals the presence of tissue damage to local immune cells. IL-33/ST2L signalling leads to the production of inflammatory cytokines/chemokines and to the induction of the immune response. Conversely, sST2 functions as a decoy receptor for IL-33, inhibiting the effects of IL-33/ST2L signalling. Animal studies have allowed the investigation of ST2 and the IL-33/ST2L signalling pathway at multiple levels. However, clinical studies have mainly focused on the determination of sST2 in the circulation. In humans, plasma concentrations of sST2 increase in several diseases, such as heart disease, pulmonary disease, burn injury and graft-versus-host disease. Consequently, increased plasma concentrations of sST2 are not specific for a single disorder in humans and are thus of limited value for diagnostic purposes. However, increased plasma concentrations of sST2 have been linked to a worse prognosis in numerous diseases. Nevertheless, the major source of circulating sST2 in healthy and diseased humans is currently not fully established. In addition, whether the downregulation of sST2 can improve the outcome of patients in the clinical setting has not been elucidated. The aim of the present review was to provide an update on the findings regarding the biochemistry and pathophysiology of ST2 and the sST2 signalling pathway in humans and experimental models.

Management of advanced heart failure: a review

INTRODUCTION

Heart failure (HF) has become a global pandemic. Despite recent developments in both medical and device treatments, HF incidences continues to increase. The current definition of HF restricts itself to stages at which clinical symptoms are apparent. In advanced heart failure (AdHF), it is universally accepted that all patients are refractory to traditional therapies. As the number of HF patients increase, so does the need for additional treatments, with an increased proportion of patients requiring advanced therapies. Areas covered: This review discusses extensive evidence for the effect of medical treatment on HF, although the data on the effect on AdHF is scare. Authors review the relevant literature for treating AdHF patients. Furthermore, mechanical circulatory devices (MCD) have emerged as an alternative to heart transplantation and have been shown to enhance quality of life and reduce mortality therefore authors also review the current literature on the different MCD and technologies. Expert commentary: More patients will need advanced therapies, as the access to heart transplantation is limited by the number of available donors. AdHF patients should be identified timely since the window of opportunities for advanced therapy is narrow as their morbidity is progressive and survival is often short.