Lucas Van Aelst

Osteoglycin Prevents Cardiac Dilatation and Dysfunction After Myocardial Infarction Through Infarct Collagen Strengthening

Rationale: To maintain cardiac mechanical and structural integrity after an ischemic insult, profound alterations occur within the extracellular matrix. Osteoglycin is a small leucine-rich proteoglycan previously described as a marker of cardiac hypertrophy. Objective: To establish whether osteoglycin may play a role in cardiac integrity and function after myocardial infarction (MI). Methods and Results: Osteoglycin expression is associated with collagen deposition and scar formation in mouse and human MI. Absence of osteoglycin in mice resulted in significantly increased rupture-related mortality with tissue disruption, intramyocardial bleeding, and increased cardiac dysfunction, despite equal infarct sizes. Surviving osteoglycin null mice had greater infarct expansion in comparison with wild-type mice because of impaired collagen fibrillogenesis and maturation in the infarcts as revealed by electron microscopy and collagen polarization. Absence of osteoglycin did not affect cardiomyocyte hypertrophy in the remodeling remote myocardium. In cultured fibroblasts, osteoglycin knockdown or supplementation did not alter transforming growth factor-&bgr; signaling. Adenoviral overexpression of osteoglycin in wild-type mice significantly improved collagen quality, thereby blunting cardiac dilatation and dysfunction after MI. In osteoglycin null mice, adenoviral overexpression of osteoglycin was unable to prevent rupture-related mortality because of insufficiently restoring osteoglycin protein levels in the heart. Finally, circulating osteoglycin levels in patients with heart failure were significantly increased in the patients with a previous history of MI compared with those with nonischemic heart failure and correlated with survival, left ventricular volumes, and other markers of fibrosis. Conclusions: Increased osteoglycin expression in the infarct scar promotes proper collagen maturation and protects against cardiac disruption and adverse remodeling after MI. In human heart failure, osteoglycin is a promising biomarker for ischemic heart failure.

miR-21 promotes fibrosis in an acute cardiac allograft transplantation model

AIMS Cardiac transplantation is the only curative therapy for end-stage heart failure. Fibrosis is one of the major causes for impaired function of cardiac allografts. MicroRNAs, a class of small non-coding RNAs, play a critical role in the development of cardiovascular disease, but the role of microRNAs in cardiac allograft failure is not well understood. METHODS AND RESULTS To uncover a role of microRNAs during cardiac graft fibrosis, we generated global microRNA profiles in allogeneic (BALB/c in C57BL/6N) and isogeneic (C57BL/6N in C57BL/6N) murine hearts after transplantation. miR-21 together with cardiac fibrosis was increased in cardiac allografts compared with isografts. Likewise, patients with cardiac rejection after heart transplantation showed increased cardiac miR-21 levels. miR-21 was induced upon treatment with IL-6 in a monocyte cell line. Overexpression of miR-21 in this monocyte cell line activated a fibrotic gene programme and promoted monocyte-to-fibrocyte transition together with activation of chemokine (C-C) motif ligand 2 (monocyte chemoattractant protein 1) via the phosphatase and tensin homologue/activator protein 1 regulatory axis. In vivo, both genetic and pharmacological inhibition of miR-21 successfully reduced fibrosis and fibrocyte accumulation in cardiac allografts. CONCLUSION Thus, inhibition of miR-21 is a novel strategy to target fibrosis development in cardiac allografts.

The role of staphylothrombin-mediated fibrin deposition in catheter-related Staphylococcus aureus infections

Staphylococcus aureus (S. aureus) is a frequent cause of catheter-related infections. S. aureus secretes the coagulases staphylocoagulase and von Willebrand factor-binding protein, both of which form a staphylothrombin complex upon binding to prothrombin. Although fibrinogen and fibrin facilitate the adhesion of S. aureus to catheters, the contribution of staphylothrombin-mediated fibrin has not been examined. In this study, we use a S. aureus mutant lacking both coagulases (Δcoa/vwb) and dabigatran, a pharmacological inhibitor of both staphylothrombin and thrombin, to address this question. Genetic absence or chemical inhibition of pathogen-driven coagulation reduced both fibrin deposition and the retention of S. aureus on catheters in vitro. In a mouse model of jugular vein catheter infection, dabigatran reduced bacterial load on jugular vein catheters, as well as metastatic kidney infection. Importantly, inhibition of staphylothrombin improved the efficacy of vancomycin treatment both in vitro and in the mouse model.

MicroRNAs as Biomarkers for Ischemic Heart Disease

MicroRNAs (miRs) are short, noncoding RNAs that function as posttranscriptional inhibitors of mRNA translation to protein. They are essential for normal development and homeostasis. Dysregulated expression patterns both cause and result from disease states. Generally studied as intracellular mediators, miRs can be isolated from body fluids and exhibit remarkable stability to degradation. These features, in combination with their tissue specificity, make miRs attractive candidates as blood-derived biomarkers for coronary artery disease (CAD), the most frequent cause of death worldwide. The use of miRs as biomarkers in both symptomatic and asymptomatic CAD and the influence of conventional cardiovascular risk factors and CAD treatment on their circulating levels are the topics of this review. To conclude, it highlights the remaining hurdles to tackle before this promising application of miRs can enter into routine clinical practice.

Matricellular proteins and matrix metalloproteinases mark the inflammatory and fibrotic response in human cardiac allograft rejection

Aims The cardiac extracellular matrix is highly involved in regulating inflammation, remodelling, and function of the heart. Whether matrix alterations relate to the degree of inflammation, fibrosis, and overall rejection in the human transplanted heart remained, until now, unknown. Methods and results Expression of matricellular proteins, proteoglycans, and metalloproteinases (MMPs) and their inhibitors (TIMPs) were investigated in serial endomyocardial biopsies (n = 102), in a cohort of 39 patients within the first year after cardiac transplantation. Out of 15 matrix-related proteins, intragraft transcript and protein levels of syndecan-1 and MMP-9 showed a strong association with the degree of cardiac allograft rejection (CAR), the expression of pro-inflammatory cytokines tumour necrosis factor (TNF)-α, interleukin (IL)-6 and transforming growth factor (TGF)-β, and with infiltrating CD3+T-cells and CD68+monocytes. In addition, SPARC, CTGF, TSP-2, MMP-14, TIMP-1, Testican-1, TSP-1, Syndecan-1, MMP-2, -9, and -14, as well as IL-6 and TGF-β transcript levels and inflammatory infiltrates all strongly relate to collagen expression in the transplanted heart. More importantly, receiver operating characteristic curve analysis demonstrated that syndecan-1 and MMP-9 transcript levels had the highest area under the curve (0.969 and 0.981, respectively), thereby identifying both as a potential decision-making tool to discriminate rejecting from non-rejecting hearts. Conclusion Out of 15 matrix-related proteins, we identified synd-1 and MMP-9 intragraft transcript levels of as strong predictors of human CAR. In addition, a multitude of non-structural matrix-related proteins closely associate with collagen expression in the transplanted heart. Therefore, we are convinced that these findings deserve further investigation and are likely to be of clinical value to prevent human CAR.

Acutely decompensated heart failure with preserved and reduced ejection fraction present with comparable haemodynamic congestion

Congestion is a central feature of acute heart failure (HF) and its assessment is important for clinical decisions (e.g. tailoring decongestive treatments). It remains uncertain whether patients with acute HF with preserved ejection fraction (HFpEF) are comparably congested as in acute HF with reduced EF (HFrEF). This study assessed congestion, right ventricular (RV) and renal dysfunction in acute HFpEF, HFrEF and non‐cardiac dyspnoea.

Iron status and inflammatory biomarkers in patients with acutely decompensated heart failure: early in-hospital phase and 30-day follow-up

Iron deficiency (ID) is an important comorbidity in heart failure (HF).1 Its reported prevalence in chronic heart failure (CHF) is 30–50% and it constitutes an independent predictor of morbidity, mortality and cardiac transplantation.2,3 Current European Society of Cardiology (ESC) guidelines for the diagnosis and management of acute and chronic HF recommend assessment of iron parameters in symptomatic HF patients with reduced ejection fraction, with ensuing iron therapy in cases of ID, as defined by the criteria used in the FAIR-HF (Ferinject Assessment in patients with IRon deficiency and chronic Heart Failure) trial.1,4 Data on ID in acutely decompensated HF (ADHF) are scarce, yet in the CardioFer study, conducted in 865 patients in France, ID showed a higher prevalence in ADHF patients (60–80%).5 In this study, we performed serial blood sampling in ADHF patients and assessed the reliability of ID diagnosis during ADHF. In addition, we wanted to evaluate the associations between parameters of iron metabolism and biomarkers of inflammation, cardiovascular stress, fibrosis and renal function. Patients were derived from the Biomarcoeurs cohort (ClinicalTrials.gov: NCT 01374880), detailed previously.6 This substudy included patients with decompensated CHF and de novo HF. Patients with a concomitant infection or myocardial ischaemia were excluded. The protocol of the study was approved by the local ethics committee and patients provided written informed consent. Following admission, blood sampling was performed at day 0 (D0) and day 30 (D30). Iron status was assessed in several ways: we considered absolute and functional ID as defined by the ESC1 thus: ID was considered to be absolute if serum ferritin was <100 μg/L, and functional when serum ferritin was 100–299 μg/L and transferrin saturation (TSAT) was <20%. Furthermore, we assessed plasma levels of hepcidin and soluble transferrin receptor (sTfR) and defined ID as represented by serum hepcidin of <14.5 ng/mL (5th percentile among healthy controls; depleted iron stores) and/or sTfR of ≥1.59 mg/L (95th percentile among healthy controls; depleted intracellular iron content in metabolizing cells).7 Several biomarkers were analysed, including brain natriuretic peptide (BNP), mid-regional–proadrenomedullin (MRproADM), procalcitonin (PCT), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), growth/differentiation factor-15 (GDF15), galectin-2, fibrinogen, soluble ST2, tumour necrosis factor-α (TNF-α) and myeloperoxidase (MPO). Statistical analyses were performed using STATA version 14.2 (StataCorp LLC, College Station, TX, USA). Groups were compared with the Student’s t-test, Wilcoxon matched-pairs signed-rank sum test, Pearson’s χ2 test or McNemar test when appropriate. A P-value of <0.05 was considered to indicate statistical significance. Forty-seven ADHF patients (32 men and 15 women) in whom assessments of ferritin and TSAT had been made at both D0 and D30 were included (data are available in supplementary material online, Tables S1 and S2). Their age (mean± standard deviation) was 70.4±13.7 years. Median BNP was 1004 pg/mL [interquartile range (IQR): 652–1676 pg/mL]. At D0, the median ferritin value was 93 μg/L (IQR: 76–107 μg/L) and median TSAT was 13% (IQR: 6–20%). Twenty-seven (57%) patients fulfilled criteria for absolute ID and 12 (26%) patients did so for functional ID. Thus, 83% of ADHF patients fulfilled the criteria for ID at admission. At D30 of follow-up and guideline-based treatments, the median ferritin value was found to have increased to 159 μg/L (IQR: 134–190 μg/L; P< 0.0001), median TSAT was 17% (IQR: 12–23%; P= 0.0176), and median BNP was 261 pg/mL (IQR: 176–462 pg/mL; P< 0.0001). Frequencies of absolute and functional ID were 11% (five patients) and 57% (27 patients), respectively. The remaining 15 patients (32%) were not ID at D30 of follow-up. Iron status changed significantly between D0 and D30 (P= 0.00001). The difference between the absence and presence of ID is clinically more important than the difference between absolute and functional ID; therefore, absolute and functional ID were combined for the purpose of comparing overall prevalences of ID between D0 and D30, which showed a trend toward statistical significance (P= 0.07) (Figure 1A) and only a moderate association between ID status at D0 and D30 (φ coefficient: 0.26). Circulating levels of hepcidin and sTfR were available for 41 patients at D0; 34 (83%) patients were identified as ID. Comparisons of ID status at D0 using either ferritin/transferrin or hepcidin/sTfR criteria are presented in Figure 1B. Twenty-eight patients (68%) were similarly categorized by both definitions, 13 patients (32%) were considered to be ID according to one but not the other definition. Based on our subsample of 41 patients, there was no difference between these iron parameters in sensitivity to detect ID at admission (P= 0.78); further analysis revealed a weak association between both tests (φ coefficient: 0.04). To explain the variation in ferritin and TSAT in parallel with adequate treatment of ADHF, we correlated the iron parameters studied with several cardiovascular and inflammatory biomarkers. ΔFerritin (ferritin at D30 minus ferritin at D0) correlated with Δsoluble ST2 (Spearman’s ρ=−0.4028; P= 0.0082) and ΔIL-6 (ρ=−0.3569; P= 0.0138), but not with ΔMR-proADM, ΔBNP, ΔPCT, ΔTNF-α, ΔhsCRP, ΔGDF15, Δgalectin-3, Δfibrinogen or ΔMPO. ΔTransferrin saturation correlated only with Δgalectin-3 (ρ=−0.3858; P= 0.0074). We did not detect a correlation between Δhepcidin or ΔsTfR and the other biomarkers studied. In conclusion, biochemical evidence of ID is common at admission for ADHF. Transferrin saturation and ferritin increase significantly over a period of 30 days following ADHF admission, which changes the ID status of patients significantly between D0 and D30 following ADHF. Thus, iron status is not stationary in ADHF patients, even during short periods of follow-up. Changing levels of circulating markers of inflammation weakly correlated with changing circulating iron parameters, which supports the suggestion that systemic inflammation contributes to alterations in iron status between admission and steady state. By contrast, changing iron

East Asia may have a better 1-year survival following an acute heart failure episode compared with Europe: results from an international observational cohort: East Asia may have a better 1-year survival following an acute heart failure episode compared with Europe: results from an international observational

Acute heart failure (AHF) is a major health problem worldwide and trials to assess novel therapies are increasingly global, as a means to reduce costs, expedite timelines, provide broad applicability, and satisfy regulatory authorities.The significant geographic differences in patient characteristics, outcomes, and treatment effect may affect trial results and raise important questions about generalizability of the results to a broader population.

Urinary Proteomics in Predicting Heart Transplantation Outcomes (uPROPHET)-Rationale and database description

Objectives Urinary Proteomics in Predicting Heart Transplantation Outcomes (uPROPHET; NCT03152422) aims: (i) to construct new multidimensional urinary proteomic (UP) classifiers that after heart transplantation (HTx) help in detecting graft vasculopathy, monitoring immune system activity and graft performance, and in adjusting immunosuppression; (ii) to sequence UP peptide fragments and to identify key proteins mediating HTx-related complications; (iii) to validate UP classifiers by demonstrating analogy between UP profiles and tissue proteomic signatures (TP) in diseased explanted hearts, to be compared with normal donor hearts; (iv) and to identify new drug targets. This article describes the uPROPHET database construction, follow-up strategies and baseline characteristics of the HTx patients. Methods HTx patients enrolled at the University Hospital Gasthuisberg (Leuven) collected mid-morning urine samples. Cardiac biopsies were obtained at HTx. UP and TP methods and the statistical work flow in pursuit of the research objectives are described in detail in the Data supplement. Results Of 352 participants in the UP study (24.4% women), 38.9%, 40.3%, 5.7% and 15.1% had ischemic, dilated, hypertrophic or other cardiomyopathy. The median interval between HTx and first UP assessment (baseline) was 7.8 years. At baseline, mean values were 56.5 years for age, 25.2 kg/m2 for body mass index, 142.3/84.8 mm Hg and 124.2/79.8 mm Hg for office and 24-h ambulatory systolic/diastolic pressure, and 58.6 mL/min/1.73 m2 for the estimated glomerular filtration rate. Of all patients, 37.2% and 6.5% had a history of mild (grade = 1B) or severe (grade ≥ 2) cellular rejection. Anti-body mediated rejection had occurred in 6.2% patients. The number of follow-up urine samples available for future analyses totals over 950. The TP study currently includes biopsies from 7 healthy donors and 15, 14, and 3 patients with ischemic, dilated, and hypertrophic cardiomyopathy. Conclusions uPROPHET constitutes a solid resources for UP and TP research in the field of HTx and has the ambition to lay the foundation for the clinical application of UP in risk stratification in HTx patients.

Urinary proteomic signatures associated with β-blockade and heart rate in heart transplant recipients

Objectives Heart transplant (HTx) recipients have a high heart rate (HR), because of graft denervation and are frequently started on β-blockade (BB). We assessed whether BB and HR post HTx are associated with a specific urinary proteomic signature. Methods In 336 HTx patients (mean age, 56.8 years; 22.3% women), we analyzed cross-sectional data obtained 7.3 years (median) after HTx. We recorded medication use, measured HR during right heart catheterization, and applied capillary electrophoresis coupled with mass spectrometry to determine the multidimensional urinary classifiers HF1 and HF2 (known to be associated with left ventricular dysfunction), ACSP75 (acute coronary syndrome) and CKD273 (renal dysfunction) and 48 sequenced urinary peptides revealing the parental proteins. Results In adjusted analyses, HF1, HF2 and CKD273 (p ≤ 0.024) were higher in BB users than non-users with a similar trend for ACSP75 (p = 0.06). Patients started on BB within 1 year after HTx and non-users had similar HF1 and HF2 levels (p ≥ 0.098), whereas starting BB later was associated with higher HF1 and HF2 compared with non-users (p ≤ 0.014). There were no differences in the urinary biomarkers (p ≥ 0.27) according to HR. BB use was associated with higher urinary levels of collagen II and III fragments and non-use with higher levels of collagen I fragments. Conclusions BB use, but not HR, is associated with a urinary proteomic signature that is usually associated with worse outcome, because unhealthier conditions probably lead to initiation of BB. Starting BB early after HTx surgery might be beneficial.