Inflammation and cardio-renal interactions in heart failure: a potential role for interleukin-6

The Need to Identify Novel Markers for Early Renal Injury in Cardiorenal Syndrome

The term "Cardiorenal Syndrome" (CRS) refers to the complex interplay between heart and kidney dysfunction. First described by Robert Bright in 1836, CRS was brought to its modern view by Ronco et al. in 2008, who defined it as one organ's primary dysfunction leading to secondary dysfunction in the other, a view that led to the distinction of five different types depending on the organ of primary dysfunction and the temporal pattern (acute vs. chronic). Their pathophysiology is intricate, involving various hemodynamic, neurohormonal, and inflammatory processes that result in damage to both organs. While traditional biomarkers have been utilized for diagnosing and prognosticating CRS, they are inadequate for the early detection of acute renal damage. Hence, there is a pressing need to discover new biomarkers to enhance clinical outcomes and treatment approaches.

Nutritional Support Reduces Circulating Cytokines in Patients with Heart Failure

Increased inflammation is associated with the pathogenesis of heart failure (HF). Increased circulating levels of cytokines have been previously reported and generally associated with worse clinical outcomes. In this context, the modulation of inflammation-related parameters seems to be a reasonable therapeutic option for improving the clinical course of the disease. Based on this, we aimed to compare changes in circulating cytokines when Mediterranean diet alone or in combination with hypercaloric, hyperproteic oral nutritional supplements (ONS), enriched with omega-3 (n-3) polyunsaturated fatty acids were administered to patients with HF. Briefly, patients were randomly assigned to receive Mediterranean Diet (control group) vs. Mediterranean Diet plus ONS (intervention group). We observed increased circulating levels of IL-6, IL-8, MCP-1 and IP-10. MCP-1 and IL-6 were associated with overweight and obesity (p = 0.01-0.01-0.04, respectively); IL-6 and IL-8 were positively correlated with fat mass and CRP serum levels (p = 0.02-0.04, respectively). Circulating levels of IL-8 significantly decreased in all patients treated with the Mediterranean diet, while IL-6 and IP-10 only significantly decreased in patients that received plus ONS. In the univariate analysis, MCP-1 and its combination with IL-6 were associated with increased mortality (p = 0.02), while the multivariate analysis confirmed that MCP-1 was an independent factor for mortality (OR 1.01, 95%ci 1.01-1.02). In conclusion, nutritional support using hypercaloric, hyperproteic, n-3 enriched ONS in combination with Mediterranean Diet was associated with decreased circulating levels of some cytokines and could represent an interesting step for improving heart functionality of patients with HF.

IL-6 is a predictor and potential therapeutic target for coronavirus disease 2019-related heart failure: A single-center retrospective study

BACKGROUND

Inflammation is linked to coronavirus disease 2019 (COVID-19)-related heart failure (HF), but the specific mechanisms are unclear. This study aimed to assess the relationship between specific inflammatory factors, such as interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-17, interferon (IFN)-α, and IFN-γ, and COVID-19-related HF.

METHODS

We retrospectively identified 212 adult patients with COVID-19 who were hospitalized at Shanghai Public Health Center from March 1 to May 30, 2022 (including 80 patients with HF and 132 without HF). High-sensitivity C-reactive protein (hs-CRP), procalcitonin (PCT), and inflammatory factors, including IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-17, IFN-α, and IFN-γ, were compared between patients with COVID-19 with and without HF.

RESULTS

Patients with COVID-19 having and not having HF differed with regard to sex, age, hs-CRP, PCT, and IL-6 levels (p < 0.05). Logistic regression analysis indicated a significant positive association between IL and 6 and HF (odds ratio = 1.055; 95 % confidence interval: 1.019-1.093, p < 0.005). Sex, age, and hs-CRP were also associated with HF. Women had a greater risk of HF than men. Older age, higher levels of hs-CRP, and IL-6 were associated with a greater risk of HF.

CONCLUSIONS

In patients with COVID-19, increased IL-6 levels are significantly associated with COVID-19-related HF.

IgM marks persistent IgG anti-human leukocyte antigen antibodies in highly sensitized heart transplant patients

BACKGROUND

Sensitization to human leukocyte antigens (HLA) is a persistent problem in heart transplant (HT) candidates. We sought to characterize the anti-HLA antibody and circulating B cell repertoire in a cohort of highly sensitized HT candidates.

METHODS

We assessed immunoglobulin G (IgG) and immunoglobulin M (IgM) anti-HLA antibodies using Luminex single antigen bead assays in a cohort of 11 highly sensitized (HS; calculated panel reactive antibody ≥ 90%) and 3 mildly sensitized (MS) candidates. We also performed B cell receptor repertoire sequencing (BCRseq) in HS candidates and 33 non-candidate controls. HLA antibody strength was measured by mean fluorescence intensity (MFI).

RESULTS

We found that IgM anti-HLA antibodies were present in all HS candidates, but with a lower breadth and strength as compared to IgG. When anti-HLA IgG specificities intersected with IgM, binding strength was higher. In contrast, there were IgM but no intersecting IgG specificities for the MS group. In four candidates in the HS group, IgG anti-HLA antibodies decreased in both breadth and strength after HT, but the decrease in strength was smaller if the IgG possessed a specificity that intersected with pre-transplant IgM. BCRseq revealed larger B cell clonotypes in HS candidates but similar diversity as compared to controls.

CONCLUSIONS

IgM marks IgG anti-HLA antibodies with higher strength before HT and persistence after HT. The presence of IgM intersecting IgG for an anti-HLA specificity may be a useful approach to determine which donor HLA should be avoided for a sensitized candidate.

Inflammation in acute heart failure

Acute heart failure (AHF) represents a common clinical scenario that requires prompt evaluation and therapy and that is characterized by a high risk of mortality or subsequent rehospitalizations. The pathophysiology leading to AHF decompensation is still not fully understood. Significant activation of inflammatory pathways has been identified in patients with AHF, particularly in its most severe forms, and it has been hypothesized that systemic inflammation has a role in AHF pathogenesis. Several inflammatory mediators and cytokines, such as high sensitivity C-reactive protein, tumor necrosis factor-α, interleukin-6, interleukin-1, soluble suppression of tumorigenicity 2 and galectin-3, have been shown to play a role in the pathogenesis, development and worsening of this condition with an independent prediction of adverse outcomes. This manuscript reviews the prevalence and prognostic value of systemic inflammation in AHF, as well as the potential role of anti-inflammatory therapies, focusing on available evidence from clinical trials and ongoing studies.

Galectin-3 as a Biomarker to Predict Cardiorenal Syndrome in Patients with Acute Heart Failure

Background

Galectin-3 affects cardiac tissue inflammation as an inflammatory mediator. The development of cardiorenal syndrome in heart failure patients is associated with a poor prognosis. This study aims to investigate whether serum galectin-3 levels can be used as a biomarker to predict cardiorenal syndrome in heart failure patients with reduced left ventricular ejection fraction.

Methods

A total of 166 symptomatic heart failure patients [New York Heart Association (NYHA) functional class II-III] with reduced left ventricular ejection fraction (≤ 40%) were recruited prospectively. Cardiorenal syndrome type 1 was defined as an acute worsening of cardiac function leading to renal dysfunction. The patients were divided into two groups with and without cardiorenal syndrome. The galectin-3 levels of all patients were determined. The primary outcome of this study was the occurrence of cardiorenal syndrome.

Results

Cardiorenal syndrome developed in 41 patients. Galectin-3 levels were found to be higher in the patients with cardiorenal syndrome (+) compared to those without cardiorenal syndrome (-) (20.7 ± 2.9 ng/mL vs. 17.8 ± 3.1 ng/mL, p < 0.001). After performing a multivariable analysis, galectin-3 levels [odds ratio (OR): 3.21, p = 0.001], NYHA functional class (OR: 1.98, p = 0.009), creatinine (OR: 3.18, p = 0.006), furosemide dose (OR: 1.21, p = 0.033), and angiotensin-converting enzyme inhibitor/angiotensin-receptor blockers usage (OR: 0.54, p = 0.029) were identified as independent predictors for the development of cardiorenal syndrome. Moreover, galectin-3 level demonstrated predictive capability for cardiorenal syndrome development (AUC = 0.761, p < 0.001).

Conclusions

Serum galectin-3 level showed an association with cardiorenal syndrome development in patients with heart failure, indicating potential usefulness as a prognostic biomarker.

Interleukin-6 in Patients With Heart Failure and Preserved Ejection Fraction

BACKGROUND

Interleukin (IL)-6 is a central inflammatory mediator and potential therapeutic target in heart failure (HF). Prior studies have shown that IL-6 concentrations are elevated in patients with HF, but much fewer data are available in heart failure with preserved ejection fraction (HFpEF).

OBJECTIVES

This study aims to determine how IL-6 relates to changes in cardiac function, congestion, body composition, and exercise tolerance in HFpEF.

METHODS

Clinical, laboratory, body composition, exercise capacity, physiologic and health status data across 4 National Heart, Lung, and Blood Institute-sponsored trials were analyzed according to the tertiles of IL-6.

RESULTS

IL-6 was measured in 374 patients with HFpEF. Patients with highest IL-6 levels had greater body mass index; higher N-terminal pro-B-type natriuretic peptide, C-reactive protein, and tumor necrosis factor-α levels; worse renal function; and lower hemoglobin levels, and were more likely to have diabetes. Although cardiac structure and function measured at rest were similar, patients with HFpEF and highest IL-6 concentrations had more severely impaired peak oxygen consumption (12.3 ± 3.3 mL/kg/min 13.1 ± 3.1 mL/kg/min 14.4 ± 3.9 mL/kg/min, P < 0.0001) as well as 6-minute walk distance (276 ± 107 m vs 332 ± 106 m vs 352 ± 116 m, P < 0.0001), even after accounting for increases in IL-6 related to excess body mass. IL-6 concentrations were associated with increases in total body fat and trunk fat, more severe symptoms during submaximal exercise, and poorer patient-reported health status.

CONCLUSIONS

IL-6 levels are commonly elevated in HFpEF, and are associated with greater symptom severity, poorer exercise capacity, and more upper body fat accumulation. These findings support testing the hypothesis that therapies that inhibit IL-6 in patients with HFpEF may improve clinical status. (Clinical Trial Registrations: Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Diastolic Heart Failure [RELAX], NCT00763867; Nitrate's Effect on Activity Tolerance in Heart Failure With Preserved Ejection Fraction, NCT02053493; Inorganic Nitrite Delivery to Improve Exercise Capacity in HFpEF, NCT02742129; Inorganic Nitrite to Enhance Benefits From Exercise Training in Heart Failure With Preserved Ejection Fraction [HFpEF], NCT02713126).

Sarcopenia: Inflammatory and Humoral Markers in Older Heart Failure Patients

BACKGROUND

Sarcopenia is highly prevalent in heart failure (HF) patients, and the involvement of biomarkers in its pathophysiology is suggested, but little has been studied concerning HF sarcopenic patients.

OBJECTIVES

To evaluate the association between inflammatory and humoral markers with sarcopenia, as well as the impact of sarcopenia on quality of life and functional capacity in older HF patients.

METHODS

In this cross-sectional study, 90 outpatient HF patients, aged ≥ 60 years, were evaluated for sarcopenia (EWGSOP2 diagnostic criteria), inflammation (high-sensitive C-reactive protein [hs-CRP], Interleukin-6 [IL-6], tumor necrosis factor alpha [TNF-α]) and humoral markers (total testosterone and insulin-like growth factor-1 [IGF-1]), physical activity (International Physical Activity Questionnaire), quality of life (Minnesota Living with Heart Failure Questionnaire), and functional capacity (6-minute walk test). The adopted level of significance was p<0.05.

RESULTS

Patients had a mean age of 69.4 ± 7.2 years, 67.8% were male, with left ventricular ejection fraction (LVEF) of 35.9 ± 11.9% and 22 (24.4%) were sarcopenic. Age (73.1 ± 8.1 and 68.3 ± 6.5 years; p= 0.006), body mass index (BMI) (23.1 ± 2.8 and 28.2 ± 4.2 kg/m2; p <0.001), and LVEF (29.9 ± 8.8 and 37.9 ± 12.1%; p= 0.005) were different between groups with and without sarcopenia, respectively. After adjusting for age, ethnicity, BMI, LVEF, and the use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers, sarcopenia was associated with higher serum levels of IL-6 and worse functional capacity.

CONCLUSION

In HF patients, sarcopenia was associated with IL-6 levels and functional capacity.

Distinct Inflammatory Milieu in Patients With Right Heart Failure

BACKGROUND

Right heart failure (RHF) is associated with worse clinical outcomes. In addition to hemodynamic perturbations, the syndrome of RHF involves liver congestion and dysfunction. The mechanisms that underlie heart-liver interactions are poorly understood and may involve secreted factors. As a first step to understand the cardiohepatic axis, we sought to elucidate the circulating inflammatory milieu in patients with RHF.

METHODS

Blood samples were collected from the inferior vena cava and hepatic veins during right heart catheterization from 3 groups of patients: (1) controls with normal cardiac function, (2) patients with heart failure who did not meet all criteria of RHF, and (3) patients who met prespecified criteria for RHF defined by hemodynamic and echocardiographic parameters. We performed a multiplex protein assay to survey levels of several circulating markers and analyzed their association with mortality and the need for a left ventricular assist device or heart transplant. Finally, we leveraged publicly available single-cell RNA sequencing data and performed tissue imaging to evaluate the expression of these factors in the liver.

RESULTS

In this study, RHF was associated with elevated levels of a subset of cytokines/chemokines/growth factors compared with controls. In particular, soluble CD163 (cluster of differentiation 163) and CXCL12 (chemokine [C-X-C motif] ligand 12) were higher in RHF and predicted left ventricular assist device/transplant-free survival in an independent validation cohort. Furthermore, single-cell RNA sequencing and immunohistochemistry of human liver biopsies suggest that these factors are expressed by Kupffer cells and may be liver derived.

CONCLUSIONS

RHF is associated with a distinct circulating inflammatory profile. Soluble CD163 and CXCL12 are novel biomarkers that can prognosticate patient outcomes. Future studies to define how these molecules influence heart failure phenotypes and disease progression may lead to new approaches to the management of patients with RHF.

A Distinct Inflammatory Milieu in Patients with Right Heart Failure

Background

Right heart failure (RHF) is associated with worse clinical outcomes. In addition to hemodynamic perturbations, the syndrome of RHF involves liver congestion and dysfunction. The mechanisms that underlie heart-liver interactions are poorly understood and may involve secreted factors. As a first step to understand the cardiohepatic axis, we sought to elucidate the circulating inflammatory milieu in patients with RHF.

Methods

Blood samples were collected from the IVC and hepatic veins during right heart catheterization from 3 groups of patients: 1) controls with normal cardiac function, 2) patients with heart failure (HF) who did not meet all criteria of RHF, and 3) patients who met prespecified criteria for RHF defined by hemodynamic and echocardiographic parameters. We performed multiplex protein assay to survey levels of several circulating markers and analyzed their association with mortality and need for left ventricular assist device or heart transplant. Finally, we leveraged publicly available single cell RNA sequencing (scRNAseq) data and performed tissue imaging to evaluate expression of these factors in the liver.

Results

In this study of 43 patients, RHF was associated with elevated levels of a subset of cytokines/chemokines/growth factors compared to controls. In particular, soluble CD163 (sCD163) and CXCL12 were higher in RHF and predicted survival in an independent validation cohort. Furthermore, scRNAseq and immunohistochemistry of human liver biopsies suggest that these factors are expressed by Kupffer cells and may be liver derived.

Conclusions

RHF is associated with a distinct circulating inflammatory profile. sCD163 and CXCL12 are novel biomarkers that can prognosticate patient outcomes. Future studies to define how these molecules influence HF phenotypes and disease progression may lead to new approaches to management of patients with RHF.

Biomarkers of Myocardial Injury and Remodeling in Heart Failure

With its complicated pathophysiology, high incidence and prevalence, heart failure remains a major public concern. In hopes of improving diagnosis, treatment and prognosis, the utility of many different biomarkers is researched vigorously around the world. In this review, biomarkers of myocardial remodeling and fibrosis (galectin-3, soluble isoform of suppression of tumorigenicity 2, matrix metalloproteinases, osteopontin, interleukin-6, syndecan-4, myostatin, procollagen type I C-terminal propeptide, procollagen type III N-terminal propeptide, vascular endothelial growth factor, nitric oxidase synthetase and asymmetric dimethylarginine), myocyte injury (heart-type fatty acid-binding protein, glutathione S-transferase P1 and heat shock protein 60), as well as iron metabolism (ferritin, transferrin saturation, soluble transferrin receptor and hepcidin), are considered in terms of possible clinical applicability and significance. Our short review consists of a summary of the aforementioned cardiovascular biomarkers’ clinical relevance and perspectives.

Incidence and Prognostic Implications of Readmissions Caused by Thrombotic Events After a Heart Failure Hospitalization

Background Readmission occurs in 1 out of 3 patients with heart failure (HF). We aimed to study the incidence and prognostic implications of rehospitalizations because of arterial thromboembolism events (ATEs) and venous thromboembolism events (VTEs) after discharge in patients with HF. Methods and Results We identified Medicare beneficiaries who were admitted with a primary diagnosis of HF from 2014 to 2019, with a hospital stay ranging between 3 and10 days, followed by discharge to home. We calculated incidence of ATEs (myocardial infarction, ischemic stroke, or systemic embolism) and VTEs (deep venous thrombosis and pulmonary embolism) up to 90 days after discharge. Out of 2 953 299 patients admitted with HF during the study period, a total of 585 353 patients met the inclusion criteria, and 36.6% were readmitted within 90 days of discharge. The incidence of readmission due ATEs, VTEs, HF, and all other reasons was 3.4%, 0.5%, 13.2%, and 19.5%, respectively. Incidence of thromboembolic events was highest within 14 days after discharge. Factors associated with ATEs included prior coronary, peripheral, or cerebrovascular disease and for VTEs included malignancy and prior liver or lung disease. ATE/VTE readmission had a 30-day mortality of 19.9%. After a median follow-up period of 25.6 months, ATE and VTE readmissions were associated with higher risk of mortality (hazard ratio, 2.76 [95% CI, 2.71-2.81] and 2.17 [95% CI, 2.08-2.27], respectively; P<0.001 for both) compared with no readmission on time-dependent Cox regression. Conclusions After a HF hospitalization, 3.9% of patients were readmitted with a thromboembolic event that was associated with 2- to 3-fold greater risk of mortality in follow-up.

Targeting Mediators of Inflammation in Heart Failure: A Short Synthesis of Experimental and Clinical Results

Inflammation has emerged as an important contributor to heart failure (HF) development and progression. Current research data highlight the diversity of immune cells, proteins, and signaling pathways involved in the pathogenesis and perpetuation of heart failure. Chronic inflammation is a major cardiovascular risk factor. Proinflammatory signaling molecules in HF initiate vicious cycles altering mitochondrial function and perturbing calcium homeostasis, therefore affecting myocardial contractility. Specific anti-inflammatory treatment represents a novel approach to prevent and slow HF progression. This review provides an update on the putative roles of inflammatory mediators involved in heart failure (tumor necrosis factor-alpha; interleukin 1, 6, 17, 18, 33) and currently available biological and non-biological therapy options targeting the aforementioned mediators and signaling pathways. We also highlight new treatment approaches based on the latest clinical and experimental research.

Inflammatory Cytokines, Immune Cells, and Organ Interactions in Heart Failure

Despite mounting evidence demonstrating the significance of inflammation in the pathophysiological mechanisms of heart failure (HF), most large clinical trials that target the inflammatory responses in HF yielded neutral or even worsening outcomes. Further in-depth understanding about the roles of inflammation in the pathogenesis of HF is eagerly needed. This review summarizes cytokines, cardiac infiltrating immune cells, and extracardiac organs that orchestrate the complex inflammatory responses in HF and highlights emerging therapeutic targets.

Interleukin-6 Signaling and Anti-Interleukin-6 Therapeutics in Cardiovascular Disease

IL (interleukin)-6 is a pivotal cytokine of innate immunity, which enacts a broad set of physiological functions traditionally associated with host defense, immune cell regulation, proliferation, and differentiation. Following recognition of innate immune pathways leading from the NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome to IL-1 to IL-6 and on to the hepatically derived clinical biomarker CRP (C-reactive protein), an expanding literature has led to understanding of the proatherogenic role for IL-6 in cardiovascular disease and thus the potential for IL-6 inhibition as a novel method for vascular protection. In this review, we provide an overview of the mechanisms by which IL-6 signaling occurs and how that impacts upon pharmacological inhibition; describe murine models of IL-6 and atherogenesis; summarize human epidemiological data outlining the utility of IL-6 as a biomarker of vascular risk; outline genetic data suggesting a causal role for IL-6 in systemic atherothrombosis and aneurysm formation; and then detail the potential role of IL-6 inhibition in stable coronary disease, acute coronary syndromes, heart failure, and the atherothrombotic complications associated with chronic kidney disease and end-stage renal failure. Finally, we review anti-inflammatory and antithrombotic findings for ziltivekimab, a novel IL-6 ligand inhibitor being developed specifically for use in atherosclerotic disease and poised to be tested formally in a large-scale cardiovascular outcomes trial focused on individuals with chronic kidney disease and elevated levels of CRP, a population at high residual atherothrombotic risk, high residual inflammatory risk, and considerable unmet clinical need.

From Systemic Inflammation to Myocardial Fibrosis: The Heart Failure With Preserved Ejection Fraction Paradigm Revisited

In accordance with the comorbidity-inflammation paradigm, comorbidities and especially metabolic comorbidities are presumed to drive development and severity of heart failure with preserved ejection fraction through a cascade of events ranging from systemic inflammation to myocardial fibrosis. Recently, novel experimental and clinical evidence emerged, which strengthens the validity of the inflammatory/profibrotic paradigm. This evidence consists among others of (1) myocardial infiltration by immunocompetent cells not only because of an obesity-induced metabolic load but also because of an arterial hypertension-induced hemodynamic load. The latter is sensed by components of the extracellular matrix like basal laminin, which also interact with cardiomyocyte titin; (2) expression in cardiomyocytes of inducible nitric oxide synthase because of circulating proinflammatory cytokines. This results in myocardial accumulation of degraded proteins because of a failing unfolded protein response; (3) definition by machine learning algorithms of phenogroups of patients with heart failure with preserved ejection fraction with a distinct inflammatory/profibrotic signature; (4) direct coupling in mediation analysis between comorbidities, inflammatory biomarkers, and deranged myocardial structure/function with endothelial expression of adhesion molecules already apparent in early preclinical heart failure with preserved ejection fraction (HF stage A, B). This new evidence paves the road for future heart failure with preserved ejection fraction treatments such as biologicals directed against inflammatory cytokines, stimulation of protein ubiquitylation with phosphodiesterase 1 inhibitors, correction of titin stiffness through natriuretic peptide-particulate guanylyl cyclase-PDE9 (phosphodiesterase 9) signaling and molecular/cellular regulatory mechanisms that control myocardial fibrosis.

Alleviation of Inflammation and Oxidative Stress in Pressure Overload-Induced Cardiac Remodeling and Heart Failure via IL-6/STAT3 Inhibition by Raloxifene

BACKGROUND

Inflammation and oxidative stress are involved in the initiation and progress of heart failure (HF). However, the role of the IL6/STAT3 pathway in the pressure overload-induced HF remains controversial.

METHODS AND RESULTS

Transverse aortic constriction (TAC) was used to induce pressure overload-HF in C57BL/6J mice. 18 mice were randomized into three groups (Sham, TAC, and TAC+raloxifene, n = 6, respectively). Echocardiographic and histological results showed that cardiac hypertrophy, fibrosis, and left ventricular dysfunction were manifested in mice after TAC treatment of eight weeks, with aggravation of macrophage infiltration and interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) expression in the myocardium. TAC (four and eight weeks) elevated the phosphorylation of signal transducer and activator of transcription 3 (p-STAT3) and prohibitin2 (PHB2) protein expression. Importantly, IL-6/gp130/STAT3 inhibition by raloxifene alleviated TAC-induced myocardial inflammation, cardiac remodeling, and dysfunction. In vitro, we demonstrated cellular hypertrophy with STAT3 activation and oxidative stress exacerbation could be elicited by IL-6 (25 ng/mL, 48 h) in H9c2 myoblasts. Sustained IL-6 stimulation increased intracellular reactive oxygen species, repressed mitochondrial membrane potential (MMP), decreased intracellular content of ATP, and led to decreased SOD activity, an increase in iNOS protein expression, and increased protein expression of Pink1, Parkin, and Bnip3 involving in mitophagy, all of which were reversed by raloxifene.

CONCLUSION

Inflammation and IL-6/STAT3 signaling were activated in TAC-induced HF in mice, while sustained IL-6 incubation elicited oxidative stress and mitophagy-related protein increase in H9c2 myoblasts, all of which were inhibited by raloxifene. These indicated IL-6/STAT3 signaling might be involved in the pathogenesis of myocardial hypertrophy and HF.

Interleukin-6 Could Be a Potential Prognostic Factor in Ambulatory Elderly Patients with Stable Heart Failure: Results from a Pilot Study

INTRODUCTION

Inflammation is a fundamental phenomenon in heart failure, but the prognostic or therapeutic role of markers such as interleukin-6 (IL-6) has not yet been clarified. The objective of this study is to describe the clinical profile of patients with elevated IL-6 and determine if they have worse clinical outcomes.

METHODS

A retrospective c.ohort observational study including 78 patients with heart failure followed up at the Heart Failure Outpatient Clinic of the Internal Medicine Department. IL-6 was determined in all patients, who were then assigned into two groups according to IL-6 level (normal or high). Clinical and prognostic data were collected to determine the differences in both groups.

RESULTS

The average age was 79 years, 60% female. A total of 53.8% of the patients had elevated IL-6 (group 2). Patients with elevated IL-6 presented more frequently with anemia mellitus (64.3% vs. 41.7%; p = 0.046), atrial fibrillation (83.3% vs. 61.9% p = 0.036), dyslipidemia (76.2% vs. 58.2%; p = 0.03), higher creatinine levels (1.35 mg/dL vs. 1.08 mg/dL; p = 0.024), lower glomerular filtration rate (43.6 mL/min/m2 vs. 59.9 mL/min/m2; p = 0.007), and anemia 25% vs. 52.4% p = 0.014. The factors independently associated with the increase in IL-6 were anemia 3.513 (1.163-10.607) and renal failure 0.963 (0.936-0.991), p < 0.05. Mortality was higher in the group with elevated IL-6 levels (16% vs. 2%; p = 0.044) with a log-rank p = 0.027 in the Kaplan-Meier curve.

CONCLUSION

Patients with heart failure and elevated IL-6 most often have atrial fibrillation, diabetes mellitus, dyslipidemia, anemia, and renal failure. In addition, mortality was higher and a tendency of higher hospital admission was observed in stable HF patients with elevated IL-6.

Inflammation in Heart Failure: JACC State-of-the-Art Review

It has long been observed that heart failure (HF) is associated with measures of systemic inflammation. In recent years, there have been significant advancements in our understanding of how inflammation contributes to the pathogenesis and progression of HF. However, although numerous studies have validated the association between measures of inflammation and HF severity and prognosis, clinical trials of anti-inflammatory therapies have proven mostly unsuccessful. On this backdrop emerges the yet unmet goal of targeting precise phenotypes within the syndrome of HF; if such precise definitions can be realized, and with better understanding of the roles played by specific inflammatory mediators, the expectation is that targeted anti-inflammatory therapies may improve prognosis in patients whose HF is driven by inflammatory pathobiology. Here, the authors describe mechanistic links between inflammation and HF, discuss traditional and novel inflammatory biomarkers, and summarize the latest evidence from clinical trials of anti-inflammatory therapies.

Heart failure in the last year: progress and perspective

Research about heart failure (HF) has made major progress in the last years. We give here an update on the most recent findings. Landmark trials have established new treatments for HF with reduced ejection fraction. Sacubitril/valsartan was superior to enalapril in PARADIGM-HF trial, and its initiation during hospitalization for acute HF or early after discharge can now be considered. More recently, new therapeutic pathways have been developed. In the DAPA-HF and EMPEROR-Reduced trials, dapagliflozin and empagliflozin reduced the risk of the primary composite endpoint, compared with placebo [hazard ratio (HR) 0.74; 95% confidence interval (CI) 0.65-0.85; P < 0.001 and HR 0.75; 95% CI 0.65-0.86; P < 0.001, respectively]. Second, vericiguat, an oral soluble guanylate cyclase stimulator, reduced the composite endpoint of cardiovascular death or HF hospitalization vs. placebo (HR 0.90; 95% CI 0.82-0.98; P = 0.02). On the other hand, both the diagnosis and treatment of HF with preserved ejection fraction, as well as management of advanced HF and acute HF, remain challenging. A better phenotyping of patients with HF would be helpful for prognostic stratification and treatment selection. Further aspects, such as the use of devices, treatment of arrhythmias, and percutaneous treatment of valvular heart disease in patients with HF, are also discussed and reviewed in this article.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

Clinical Characteristics of De Novo Heart Failure and Acute Decompensated Chronic Heart Failure: Are They Distinctive Phenotypes That Contribute to Different Outcomes?

Heart failure is currently one of the leading causes of morbidity and mortality. Patients with heart failure often present with acute symptoms and may have a poor prognosis. Recent evidence shows differences in clinical characteristics and outcomes between de novo heart failure (DNHF) and acute decompensated chronic heart failure (ADCHF). Based on a better understanding of the distinct pathophysiology of these two conditions, new strategies may be considered to treat heart failure patients and improve outcomes. In this review, the authors elaborate distinctions regarding the clinical characteristics and outcomes of DNHF and ADCHF and their respective pathophysiology. Future clinical trials of therapies should address the potentially different phenotypes between DNHF and ADCHF if meaningful discoveries are to be made.

The clinical significance of interleukin-6 in heart failure: results from the BIOSTAT-CHF study

AIMS

Inflammation is a central process in the pathophysiology of heart failure (HF), but trials targeting tumour necrosis factor (TNF)-α were largely unsuccessful. Interleukin (IL)-6 is an important inflammatory mediator and might constitute a potential pharmacologic target in HF. However, little is known regarding the association between IL-6 and clinical characteristics, outcomes and other inflammatory biomarkers in HF. We thus aimed to identify and characterize these associations.

METHODS AND RESULTS

Interleukin-6 was measured in 2329 patients [89.4% with a left ventricular ejection fraction (LVEF) ≤ 40%] of the BIOSTAT-CHF cohort. The primary outcome was all-cause mortality and HF hospitalization during 2 years, with all-cause, cardiovascular (CV), and non-CV death as secondary outcomes. Approximately half (56%) of all included patients had plasma IL-6 values greater than the previously determined 95th percentile of normal values at baseline. Elevated N-terminal pro-brain natriuretic peptide, procalcitonin and hepcidin, younger age, TNF-α/IL-1-related biomarkers, or having iron deficiency, atrial fibrillation and LVEF > 40% independently predicted elevated IL-6 levels. IL-6 independently predicted the primary outcome [HR (95% confidence interval) per doubling: 1.16 (1.11-1.21), P < 0.001], all-cause mortality [1.22 (1.16-1.29), P < 0.001] and CV as well as non-CV mortality [1.16 (1.09-1.24), P < 0.001; 1.31 (1.18-1.45), P < 0.001], but did not improve discrimination in previously published risk models.

CONCLUSIONS

In a large, heterogeneous cohort of HF patients, elevated IL-6 levels were found in more than 50% of patients and were associated with iron deficiency, reduced LVEF, atrial fibrillation and poorer clinical outcomes. These findings warrant further investigation of IL-6 as a potential therapeutic target in specific HF subpopulations.

Serum and Urine Albumin and Response to Loop Diuretics in Heart Failure

BACKGROUND AND OBJECTIVES

Diuretic resistance can limit successful decongestion of patients with heart failure. Because loop diuretics tightly bind albumin, low serum albumin and high urine albumin can theoretically limit diuretic delivery to the site of action. However, it is unknown if this represents a clinically relevant mechanism of diuretic resistance in human heart failure.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In total, 208 outpatients with heart failure at the Yale Transitional Care Center undergoing diuretic treatment were studied. Blood and urine chemistries were collected at baseline and 1.5 hours postdiuretic administration. Urine diuretic levels were normalized to urine creatinine and adjusted for diuretic dose administered, and diuretic efficiency was calculated as sodium output per doubling of the loop diuretic dose. Findings were validated in an inpatient heart failure cohort (n=60).

RESULTS

Serum albumin levels in the outpatient cohort ranged from 2.4 to 4.9 g/dl, with a median of 3.7 g/dl (interquartile range, 3.5-4.1). Serum albumin had no association with urinary diuretic delivery (r=-0.05; P=0.52), but higher levels weakly correlated with better diuretic efficiency (r=0.17; P=0.02). However, serum albumin inversely correlated with systemic inflammation as assessed by plasma IL-6 (r=-0.35; P<0.001), and controlling for IL-6 eliminated the diuretic efficiency-serum albumin association (r=0.12; P=0.12). In the inpatient cohort, there was no association between serum albumin and urinary diuretic excretion (r=0.15; P=0.32) or diuretic efficiency (r=-0.16; P=0.25). In the outpatient cohort, 39% of patients had microalbuminuria, and 18% had macroalbuminuria. There was no correlation between albuminuria and diuretic efficiency after adjusting for kidney function (r=-0.02; P=0.89). Results were similar in the inpatient cohort.

CONCLUSIONS

Serum albumin levels were not associated with urinary diuretic excretion, and urinary albumin levels were not associated with diuretic efficiency.