Increased endothelial monocyte adhesiveness is related to clinical outcomes in chronic heart failure

HFrEF subphenotypes based on 4210 repeatedly measured circulating proteins are driven by different biological mechanisms

BACKGROUND

HFrEF is a heterogenous condition with high mortality. We used serial assessments of 4210 circulating proteins to identify distinct novel protein-based HFrEF subphenotypes and to investigate underlying dynamic biological mechanisms. Herewith we aimed to gain pathophysiological insights and fuel opportunities for personalised treatment.

METHODS

In 382 patients, we performed trimonthly blood sampling during a median follow-up of 2.1 [IQR:1.1-2.6] years. We selected all baseline samples and two samples closest to the primary endpoint (PEP; composite of cardiovascular mortality, HF hospitalization, LVAD implantation, and heart transplantation) or censoring, and applied an aptamer-based multiplex proteomic approach. Using unsupervised machine learning methods, we derived clusters from 4210 repeatedly measured proteomic biomarkers. Sets of proteins that drove cluster allocation were analysed via an enrichment analysis. Differences in clinical characteristics and PEP occurrence were evaluated.

FINDINGS

We identified four subphenotypes with different protein profiles, prognosis and clinical characteristics, including age (median [IQR] for subphenotypes 1-4, respectively:70 [64, 76], 68 [60, 79], 57 [47, 65], 59 [56, 66]years), EF (30 [26, 36], 26 [20, 38], 26 [22, 32], 33 [28, 37]%), and chronic renal failure (45%, 65%, 36%, 37%). Subphenotype allocation was driven by subsets of proteins associated with various biological functions, such as oxidative stress, inflammation and extracellular matrix organisation. Clinical characteristics of the subphenotypes were aligned with these associations. Subphenotypes 2 and 3 had the worst prognosis compared to subphenotype 1 (adjHR (95%CI):3.43 (1.76-6.69), and 2.88 (1.37-6.03), respectively).

INTERPRETATION

Four circulating-protein based subphenotypes are present in HFrEF, which are driven by varying combinations of protein subsets, and have different clinical characteristics and prognosis.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01851538https://clinicaltrials.gov/ct2/show/NCT01851538.

FUNDING

EU/EFPIA IMI2JU BigData@Heart grant n°116074, Jaap Schouten Foundation and Noordwest Academie.

Circulating Biomarkers of Cell Adhesion Predict Clinical Outcome in Patients with Chronic Heart Failure

Cardiovascular inflammation and vascular endothelial dysfunction are involved in chronic heart failure (CHF), and cellular adhesion molecules are considered to play a key role in these mechanisms. We evaluated temporal patterns of 12 blood biomarkers of cell adhesion in patients with CHF. In 263 ambulant patients, serial, tri-monthly blood samples were collected during a median follow-up of 2.2 (1.4–2.5) years. The primary endpoint (PE) was a composite of cardiovascular mortality, HF hospitalization, heart transplantation and implantation of a left ventricular assist device and was reached in 70 patients. We selected the baseline blood samples in all patients, the two samples closest to a PE, or, for event-free patients, the last sample available. In these 567 samples, associations between biomarkers and PE were investigated by joint modelling. The median age was 68 (59–76) years, with 72% men and 74% New York Heart Association class I–II. Repeatedly measured levels of Complement component C1q receptor (C1qR), Cadherin 5 (CDH5), Chitinase-3-like protein 1 (CHI3L1), Ephrin type-B receptor 4 (EPHB4), Intercellular adhesion molecule-2 (ICAM-2) and Junctional adhesion molecule A (JAM-A) were independently associated with the PE. Their rates of change also predicted clinical outcome. Level of CHI3L1 was numerically the strongest predictor with a hazard ratio (HR) (95% confidence interval) of 2.27 (1.66–3.16) per SD difference in level, followed by JAM-A (2.10, 1.42–3.23) and C1qR (1.90, 1.36–2.72), adjusted for clinical characteristics. In conclusion, temporal patterns of C1qR, CDH5, CHI3L1, EPHB4, ICAM2 and JAM-A are strongly and independently associated with clinical outcome in CHF patients.

Increased expression of cell adhesion molecule receptors on monocyte subsets in ischaemic heart failure

The objective of this study was to evaluate the expression of cell adhesion molecule (CAM) receptors (integrins) on monocyte subsets in heart failure (HF) and examine their prognostic implication. Increased levels of soluble CAMs have been observed in patients with HF, but the precise mechanism of monocyte adhesion to the vascular endothelium remains unknown. Patients with acute HF (AHF, n=51) were compared to those with stable HF (SHF, n=42) and stable coronary artery disease (CAD, n=44) without HF. Expression of integrins-receptors to intercellular adhesion molecule-1 (ICAM-1R) and vascular CAM-1 (VCAM-1R) on monocyte subsets was assessed by flow cytometry. Monocyte subsets were defined as CD14++CD16–CCR2+ (‘classical’, Mon1), CD14++CD16+CCR2+ (‘intermediate’, Mon2), and CD14+CD16++CCR2– (‘non-classical’, Mon3). Compared to patients with SHF, those with AHF had significantly higher expression of ICAM-1R on Mon2 (p=0.01). Compared to those with stable CAD, patients with SHF had a significantly higher expression of ICAM-1R on Mon2 (p=0.025). Compared to SHF, patients with AHF had a similar expression of VCAM-1R on both Mon1 and Mon3 but significantly higher expression on Mon2 (p=0.019). There were no significant differences between SHF and CAD in monocyte expression of VCAM-1R. In multivariate Cox regression analysis, VCAM-1R expression on Mon2 was associated with adverse clinical outcome (death or rehospitalisation) in AHF [HR 1.07 (1.01–1.14), p=0.029]. In conclusion, HF is associated with increased monocyte expression of integrins-receptors to both ICAM-1 and VCAM-1, being particularly linked to Mon2 subset. Expression of VCAM-1R on Mon2 may have prognostic value in patients with AHF.

Clinical Effect of Cardiac Shock Wave Therapy on Myocardial Ischemia in Patients With Ischemic Heart Failure

Background:

Cardiac shock wave therapy (CSWT) can improve myocardial ischemia and cardiac function in patients with coronary artery disease and refractory angina. The aim of the study was to test its potential role to relieve symptoms in patients with ischemic heart failure (HF) and to identify CSWT-affected genes.

Methods:

Cardiac shock wave therapy was performed on 23 patients (mean age: 67 ± 6 years) with ischemic HF 3 times per week for 3 weeks. Clinical assessment parameters were measured for all patients, and peripheral blood mononuclear cells (PBMCs) were isolated from whole blood of all patients 3 days before CSWT and 1 week after the 3-week CSWT schedule. RNA sequencing of PBMCs collected from 3 patients before and after CSWT was performed on the Illumina Genome Analyzer. Gene expression was determined by quantitative reverse transcription–polymerase chain reaction.

Results:

Cardiac shock wave therapy significantly attenuated myocardial ischemia and severity of angina, health-related quality of life, and myocardial blood flow as estimated by New York Heart Association class, Canadian Cardiovascular Society classification, Seattle Angina Questionnaire, and single photon emission computed tomography images, respectively. We then tried to investigate how CSWT improved myocardial ischemia by RNA sequencing on PBMCs. Gene set enrichment analysis on the sequencing data revealed that CSWT treatment was positively correlated with cytokine and cytokine receptor interaction and chemokine signaling pathway. Furthermore, we demonstrated that CSWT resulted in a significant increase in the expression of promoters of neovascularization (vascular endothelial growth factor A [VEGF-A], VEGF-B, chemokine (C-X-C motif) ligand 1 [CXCL1], CXCL2, CXCL3 and TNFRSF12A) and a notable decrease in the expression of a mediator of cell apoptosis (mitogen-activated protein kinase 9).

Conclusions:

Cardiac shock wave therapy can improve myocardial ischemia and represents as a treatment option for patients with ischemic HF through promoting neovascularization and inhibiting cell apoptosis.

Iron sucrose accelerates early atherogenesis by increasing superoxide production and upregulating adhesion molecules in CKD

High-dose intravenous iron supplementation is associated with adverse cardiovascular outcomes in patients with CKD, but the underlying mechanism is unknown. Our study investigated the causative role of iron sucrose in leukocyte-endothelium interactions, an index of early atherogenesis, and subsequent atherosclerosis in the mouse remnant kidney model. We found that expression levels of intracellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and adhesion of U937 cells increased in iron-treated human aortic endothelial cells through upregulated NADPH oxidase (NOx) and NF-κB signaling. We then measured mononuclear-endothelial adhesion and atherosclerotic lesions of the proximal aorta in male C57BL/6 mice with subtotal nephrectomy, male apolipoprotein E-deficient (ApoE(-/-)) mice with uninephrectomy, and sham-operated mice subjected to saline or parenteral iron loading. Iron sucrose significantly increased tissue superoxide production, expression of tissue cell adhesion molecules, and endothelial adhesiveness in mice with subtotal nephrectomy. Moreover, iron sucrose exacerbated atherosclerosis in the aorta of ApoE(-/-) mice with uninephrectomy. In patients with CKD, intravenous iron sucrose increased circulating mononuclear superoxide production, expression of soluble adhesion molecules, and mononuclear-endothelial adhesion compared with healthy subjects or untreated patients. In summary, iron sucrose aggravated endothelial dysfunction through NOx/NF-κB/CAM signaling, increased mononuclear-endothelial adhesion, and exacerbated atherosclerosis in mice with remnant kidneys. These results suggest a novel causative role for therapeutic iron in cardiovascular complications in patients with CKD.

Intravenous ferric chloride hexahydrate supplementation induced endothelial dysfunction and increased cardiovascular risk among hemodialysis patients

Background

The association between intravenous (IV) iron administration and outcomes in hemodialysis (HD) patients is still debated. Therefore, this study was aimed to assess the relationship between the IV administration of ferric chloride hexahydrate (Atofen®) and cardiovascular (CV) outcome and the interaction between iron-induced oxidative stress and endothelial dysfunction in chronic HD patients.

Methodology/Principal Findings

A cohort of 1239 chronic HD patients was recruited. In a follow-up of 12 months, Kaplan-Meier survival curves showed that higher doses of IV Atofen associated with higher risks for CV events and deaths in HD patients. In multivariate Cox models, compared to no iron supplementation, IV Atofen administration was an independent predictor for CV events and overall mortality. However, the nature of the observational cohort study possibly bears selection bias. We further found that IV Atofen enhanced the superoxide production of mononuclear cells (MNCs), the levels of circulating soluble adhesion molecules, and the adhesion of MNCs to human aortic endothelial cells (HAECs). In vitro experiments showed that Atofen increased the expression of intracellular cell adhesion molecule-1 and vascular cell adhesion molecule-1 in HAECs and aggravated the endothelial adhesiveness in a dose-dependent manner. These iron-induced changes were significantly attenuated by the co-treatment of HAECs with N-acetylcysteine and inhibitors of NADPH oxidase, nuclear factor κB, and activator protein-1.

Conclusion

A cumulative dose of IV Atofen >800 mg within 6 months was associated with an adverse CV outcome and a higher mortality among chronic HD patients. The detrimental effects of IV iron supplementation were partly due to the increased oxidative stress and induction of MNC adhesion to endothelial cells, a pivotal index of early atherogenesis.

The role of monocytes and inflammation in the pathophysiology of heart failure

There is growing evidence to support an important role of inflammation in the underlying pathophysiology of heart failure (HF). Indeed, inflammatory cytokine levels are well recognized to be increased in patients with left ventricular dysfunction and appear to have prognostic implications. Monocytes play a pivotal role in the inflammatory cascade and are a major source of both pro- and anti-inflammatory cytokines. They are intimately involved in tissue damage and repair and an imbalance of these processes may have detrimental consequences for the failing myocardium. Importantly, monocytes comprise of distinct subsets with different cell surface markers and functional characteristics and this heterogeneity may be important in understanding their specific role in HF. In HF, monocyte activation involves interplay between pattern recognition molecules, endotoxins, cytokines, and acute phase proteins. Activated monocytes migrate to the myocardium in response to powerful chemokines, where they must then attach to the endothelial wall before infiltrating into the myocardium itself. This review article aims to discuss the role of monocytes and inflammation in HF, focusing on monocyte activation, mobilisation, recruitment and endothelial adherence, as well as the effects they may have on myocardial performance. The therapeutic modulation of inflammation and monocyte activation in HF treatment will also be reviewed.

Fenofibrate attenuates endothelial monocyte adhesion in chronic heart failure: an in vitro study

BACKGROUND

Inflammation is implicated in chronic heart failure (CHF). In this study, the potential inhibitory effect of peroxisome proliferator-activated receptor-alpha (PPARalpha) activator fenofibrate on monocyte adhesion in CHF patients was investigated in vitro.

MATERIALS AND METHODS

Isolated peripheral blood mononuclear cells (PBMCs) were collected from 36 patients (aged 65 +/- 8 years) with symptomatic CHF and from 12 healthy control subjects. The cultured human aortic endothelial cells (HAECs) were stimulated with or without 2 ng mL(-1) tumour necrosis factor-alpha (TNF-alpha) and the inhibitory effects of fenofibrate at 25, 50, 100 and 200 microM on endothelial mononuclear cell adhesion were tested. Furthermore, the HAECs were stimulated with 70% sera obtained from CHF patients and control individuals, respectively, with or without pretreatments with fenofibrate. The endothelial expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) was then confirmed by mRNA expression and Western blot.

RESULTS

We found that the increased adhesion of PBMCs to TNF-alpha-stimulated HAECs in CHF patients was reduced when the HAECs were pretreated with fenofibrate (31% inhibition, P = 0.0121). However, pretreatment of the isolated PBMCs collected from CHF patients with fenofibrate failed to suppress their adherence to TNF-alpha-stimulated HAECs. Furthermore, stimulation of cultured HAECs with CHF patient sera significantly increased VCAM-1 and ICAM-1 expression, which could also be inhibited by fenofibrate.

CONCLUSIONS

The fenofibrate directly inhibits monocyte binding by TNF-alpha-activated HAECs, probably through preventing up-regulation of cell adhesion molecules by endothelial cells in response to inflammatory stimuli. This PPARalpha activator may have the potential to ameliorate vascular inflammation in patients with CHF.

The immune system and chronic heart failure: is the heart in control?

Despite current treatment options, the clinical course of patients with chronic heart failure is notoriously difficult to predict. Among those with similar etiologies, ejection fractions, and patient demographics, our understanding of why such variations in outcomes exist remains limited. Evidence that has been progressively gathered implicates an important role of the immune system in the propagation of heart failure. This has been derived mainly from observations that cytokines are progressively elevated in patients with poor outcomes. However, attempts at introducing various immunomodulatory therapies as a new treatment strategy have been largely unsuccessful to date. This possibly reflects a failure in recognizing the complexity of the immune system's role in chronic heart failure, which has led to an oversimplified approach to treatment. This review critically analyzes the immune treatments attempted to date and hypothesizes what is required to develop a successful future treatment strategy.