Systemic inflammation in heart failure--the whys and wherefores

Expression of pericardial fluid T-cells and related inflammatory cytokines in patients with chronic heart failure

Pericardial fluid, as a biochemical indicator of heart status, directly indicates pathological alteration to the heart. The accumulation of pericardial fluid can be attributed to an underlying systemic or local inflammatory process. However, the pericardial fluid expression of cellular surface markers, as well as several cytokines in chronic heart failure (CHF), remain unclear. In order to evaluate these issues further the pericardial fluid expression of several cytokines and the surface expression of activity markers between CHF patients and non-heart failure (NHF) patients were analyzed. The pericardial fluid expression of cytokines was measured by immunofluorescence and biomarker of plasma N-terminal propeptide of B-type natriuretic peptide (NT-proBNP), while pericardial fluid levels of soluble glycoprotein 130 (sgp130) were analyzed by ELISA in 50 CHF and 24 NHF patients. In addition, the surface expression of activation markers for T-cells was measured by immunohistochemistry. Patients with CHF demonstrated increased levels of plasma NT-proBNP and pericardial fluid sgp130. Surface expression of cellular activation markers CD25 and Foxp3 in the pericardial fluid was increased in patients with CHF. Moreover, the pro- and anti-inflammatory cytokines interferon (IFN)-γ, interleukin (IL)-6 and IL-10 in patients with CHF also demonstrated an increased expression within its pericardial fluid. In addition, there was infiltration of inflammatory cells and enhanced expression of inflammatory cytokines in the pericardial fluid of patients with CHF, which may reflect T cell activation, suggesting that systemic inflammation is important in the progression of CHF. This evidence could indicate a possible novel target for future therapeutics and prevention of CHF.

T cell costimulation blockade blunts pressure overload-induced heart failure

Heart failure (HF) is a leading cause of mortality. Inflammation is implicated in HF, yet clinical trials targeting pro-inflammatory cytokines in HF were unsuccessful, possibly due to redundant functions of individual cytokines. Searching for better cardiac inflammation targets, here we link T cells with HF development in a mouse model of pathological cardiac hypertrophy and in human HF patients. T cell costimulation blockade, through FDA-approved rheumatoid arthritis drug abatacept, leads to highly significant delay in progression and decreased severity of cardiac dysfunction in the mouse HF model. The therapeutic effect occurs via inhibition of activation and cardiac infiltration of T cells and macrophages, leading to reduced cardiomyocyte death. Abatacept treatment also induces production of anti-inflammatory cytokine interleukin-10 (IL-10). IL-10-deficient mice are refractive to treatment, while protection could be rescued by transfer of IL-10-sufficient B cells. These results suggest that T cell costimulation blockade might be therapeutically exploited to treat HF.

Abatacept is an FDA-approved drug used for treatment of rheumatoid arthritis. Here the authors show that abatacept reduces cardiomyocyte death in a mouse model of heart failure by inhibiting activation and heart infiltration of T cells and macrophages, an effect mediated by IL-10, suggesting a potential therapy for heart failure.

The impact of cardiac resynchronization therapy on routine laboratory parameters

Background

Cardiac resynchronization therapy (CRT) in chronic heart failure has been shown to improve mortality and morbidity. However, comprehensive data are not available as concerns how circulating biomarkers reflecting different organ functions, such as serum uric acid, blood urea nitrogen (BUN), albumin, cholesterol, or various liver enzymes, change over time as a consequence of CRT. The aim of this prospective study was to overview these possible changes.

Methods

A total of 20 routine laboratory parameters were measured in 122 control subjects and in 129 patients with chronic heart failure before CRT, 6 months, and 2 years later.

Results

The levels of serum uric acid [before: 432 (331–516) mmol/L, 6-month: 372 (304–452) mmol/L, 2-year: 340 (290–433) mmol/L; p < 0.001] and BUN [8.3 (6.4–11.5) mmol/L, 8.0 (6.3–11.1) mmol/L, 6.8 (5.0–9.7) mmol/L; p < 0.001) reduced statistically significant. Total bilirubin underwent reduction [16 (11–23) μmol/L, 11 (7–14) μmol/L, 8 (7–13) μmol/L; p < 0.001], while albumin increased [45 (43–48) g/L, 46 (44–48) g/L, 46 (43–48) g/L; p = 0.04]. Cholesterol concentrations elevated [4.3 (3.6–5.0) mmol/L, 4.5 (3.8–5.1) mmol/L, 4.6 (3.8–5.4) mmol/L; p < 0.001] and glucose decreased [6.2 (5.6–7.2) mmol/L, 5.9 (5.1–6.7) mmol/L, 5.7 (5.1–6.8) mmol/L; p < 0.001].

Conclusions

CRT influences the levels of routinely used biomarkers suggesting improvements in renal function, liver capacity, and metabolic changes. These changes could mirror the multiorgan improvement after CRT.

Serum Soluble Urokinase-Type Plasminogen Activator Receptor Is Associated with Low Left Ventricular Ejection Fraction and Elevated Plasma Brain-Type Natriuretic Peptide Level

BACKGROUND

Recent studies have suggested that soluble urokinase plasminogen activator receptor (suPAR), a biomarker of subclinical levels of inflammation, is significantly correlated with cardiovascular events.

PURPOSE

We investigated the association between suPAR and left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI), and plasma B-type natriuretic peptide (BNP) among cardiac inpatients.

METHODS AND RESULTS

In total, 242 patients (mean age 71.3 ± 9.8 years; 70 women) admitted to the cardiology department were enrolled in the study. suPAR was significantly correlated with LVEF (R = -0.24, P<0.001), LVMI (R = 0.16, P = 0.014) and BNP (R = 0.46, P<0.001). In logistic regression analysis, the highest suPAR tertile (> 3236 pg/mL) was associated with low LVEF (< 50%) and elevated BNP (> 300 pg/mL) with an odds ratio of 3.84 (95% confidence interval [CI], 1.22-12.1) and 5.36 (95% CI, 1.32-21.8), respectively, after adjusting for age, sex, log-transformed estimated glomerular filtration rate (log(eGFR)), C-reactive protein, and diuretic use. The association between suPAR and LVMI was not statistically significant. In multivariate receiver operating characteristic analysis, addition of log(suPAR) to the combination of age, sex, log(eGFR) and CRP incrementally improved the prediction of low LVEF (area under the curve [AUC], 0.827 to 0.852, P = 0.046) and BNP ≥ 300 pg/mL (AUC, 0.869 to 0.906; P = 0.029).

CONCLUSIONS

suPAR was associated with low LVEF and elevated BNP, but not with left ventricular hypertrophy, independent of CRP, renal function, and diuretic use among cardiac inpatients who were not undergoing chronic hemodialysis.

Inflammatory response and endothelial dysfunction in the hearts of mice co-exposed to SO2 , NO2 , and PM2.5

SO2 , NO2 , and PM2.5 are typical air pollutants produced during the combustion of coal. Increasing evidence indicates that air pollution has contributed to the development and progression of heart-related diseases over the past decades. However, little experimental data and few studies of SO2 , NO2 , and PM2.5 co-exposure in animals exist; therefore, the relevant mechanisms underlying this phenomenon are unclear. An important characteristic of air pollution is that co-exposure persists at a low concentration throughout a lifetime. In the present study, we treated adult mice with SO2 , NO2 , and PM2.5 at various concentrations (0.5 mg/m3 SO2 , 0.2 mg/m3 NO2 6 h/d, with intranasal instillation of 1 mg/kg PM2.5 every other day during these exposures; or 3.5 mg/m3 SO2 , 2 mg/m3 NO2 6 h/d, and 10 mg/kg PM2.5 for 28 d). Blood pressure (BP), heart rate (HR), histopathological damage, and inflammatory and endothelial cytokines in the heart were assessed. The results indicate that co-exposure caused endothelial dysfunction by elevating endothelin-1 (ET-1) expression and repressing the endothelial nitric oxide synthase (eNOS) level as well as stimulating the inflammatory response by increasing the levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Additionally, these alterations were confirmed by histological staining. Furthermore, we observed decreased BP and increased HR after co-exposure. Our results indicate that co-exposure to SO2 , NO2 , and PM2.5 may be a major risk factor for cardiac disease and may induce injury to the hearts of mammals and contribute to heart disease. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1996-2005, 2016.

Evaluation of Innate Immunity Biomarkers on Admission and at Discharge From an Acute Heart Failure Episode

BACKGROUND

The involvement of the immune system in heart failure (HF) has been demonstrated. Evidence shows that innate immunity can have a role in the remodeling process and progression of HF. With previous studies showing the prognostic value of some innate immunity markers and their relevance in this condition, we aim to evaluate how these markers vary on hospitalization due to an acute episode of HF and at discharge.

METHODS

About 154 patients admitted with acute HF were prospectively recruited. Patients were evaluated on admission and at discharge from the hospital. Patients with infection were separately analyzed. Innate immunity, inflammatory, and cardiac biomarkers were measured and were compared between groups and between admission and discharge and with reference values of biological variation.

RESULTS

Median patients' age was 78 years, and half of the patients were men. The median duration of hospitalization was 6 days. C3 and C4 protein levels significantly increased (P < 0.001) between admission and discharge, as well as eosinophils (P < 0.001) and BNP levels decreased (P < 0.001). Variation in all these variables was independent of infection and biological variation.

CONCLUSION

Our results show that innate immunity markers such as C3 and C4 increase after treatment for acute HF, supporting the hypothesis that they can be involved in the resolution of the acute episode.

Hospitalized Patients with Heart Failure and Common Bacterial Infections: A Nationwide Analysis of Concomitant Clostridium Difficile Infection Rates and In-Hospital Mortality

BACKGROUND

Patients with heart failure (HF) are frequently hospitalized with common bacterial infections. It is unknown whether they experience concomitant Clostridium difficile infection (CDI) more frequently than patients without HF, and whether CDI affects their mortality.

METHODS

We used 2012 National Inpatient Sample data to determine the rate of CDI and associated in-hospital mortality for hospitalized patients with comorbid HF and urinary tract infection (UTI), pneumonia (PNA), or sepsis. Univariate and multivariate analyses were performed. Weighted data are presented.

RESULTS

There were an estimated 5,851,582 patient hospitalizations with discharge diagnosis of UTI, PNA, or sepsis in 2012 in the United States. Of these, 23.4% had discharge diagnosis of HF. Patients with HF were on average older and had more comorbidities. CDI rates were higher in hospitalizations with discharge diagnosis of HF compared with those without HF (odds ratio 1.13, 95% confidence interval 1.10-1.16) after controlling for patient demographics and comorbidities and hospital characteristics. Among HF hospitalizations with UTI, PNA, or sepsis, those with concomitant CDI had a higher in-hospital mortality than those without concomitant CDI (odds ratio 1.81, 95% confidence interval 1.71-1.92) after controlling for the covariates outlined previously.

CONCLUSIONS

HF is associated with higher CDI rates among hospitalized patients with other common bacterial infections, even when adjusting for other known risk factors for CDI. Among these patients with comorbid HF, CDI is associated with markedly higher in-hospital mortality. These findings may suggest an opportunity to improve outcomes for hospitalized patients with HF and common bacterial infections, possibly through improved Clostridium difficile screening and prophylaxis protocols.

Risk stratification based on nutritional screening on admission: Three-year clinical outcomes in hospitalized patients with acute heart failure syndrome

BACKGROUND

Several blood tests are commonly used to assess nutritional status, including serum albumin levels (SAL) and lymphocyte counts (LC). The aim of this study is to investigate whether nutritional screening on admission can be used to determine risk levels for adverse clinical events in acute heart failure syndrome (AHFS) patients.

METHODS

In 432 consecutive AHFS patients, we measured SAL and LC and prospectively followed the patients for their combined clinical events (all-cause death and re-hospitalization for heart failure) for three years from admission. The classification and regression tree (CART) tool identified the cut-off criteria for SAL and LC to differentiate among patients with different risks of clinical events as 3.5g/dl and 963/mm³, respectively.

RESULTS

The CART tool classified 15.5% patients as high risk, 15.7% as intermediate risk, and 68.8% as low risk. The CART for nutritional status (CART-NS) values were strongly correlated with combined clinical events [hazard ratio of 2.13 (low vs high risk), 95% confidence interval of 1.42-3.16, p<0.001], even after adjusting for plasma brain natriuretic peptide levels. The CART-NS analysis improved the specificity (89.5%) of predictions of clinical outcomes with the comparable sensitivity (36.3%) compared with the use of a single criterion (SAL <3.5g/dl: 70.2, 42.4% or LC <963/mm³: 73.4, 41.7%, respectively).

CONCLUSION

A substantial proportion of AHFS patients are at risk of malnutrition, and this risk is associated with poor clinical outcomes. We demonstrate that this algorithm for nutritional screening, even in emergency clinical settings, can determine risk levels for further adverse events in AHFS patients.

Gastrointestinal and Liver Issues in Heart Failure

Heart failure affects ≈23 million people worldwide and continues to have a high mortality despite advancements in modern pharmacotherapy and device therapy. HF is a complex clinical syndrome that can result in the impairment of endocrine, hematologic, musculoskeletal, renal, respiratory, peripheral vascular, hepatic, and gastrointestinal systems. Although gastrointestinal involvement and hepatic involvement are common in HF and are associated with increased morbidity and mortality, their bidirectional association with HF progression remains poorly fathomed. The current understanding of multiple mechanisms, including proinflammatory cytokine milieu, hormonal imbalance, and anabolic/catabolic imbalance, has been used to explain the relationship between the gut and HF and has been the basis for many novel therapeutic strategies. However, the failure of these novel therapies such as anti–tumor necrosis factor-α has resulted in further complexity. In this review, we describe the involvement of the gastrointestinal and liver systems within the HF syndrome, their pathophysiological mechanisms, and their clinical consequences.

New therapy, new challenges: The effects of long-term continuous flow left ventricular assist device on inflammation

Surgically implanted continuous flow left ventricular assist devices (CF-LVADs) are currently used in patients with end-stage heart failure (HF). However, CF-LVAD therapy introduces a new set of complications and adverse events in these patients. Major adverse events with the CF-LVAD include right heart failure, vascular dysfunction, stroke, hepatic failure, and multi-organ failure, complications that may have inflammation as a common etiology. Our aim was to review the current evidence showing a relationship between these adverse events and elevated levels of inflammatory biomarkers in CF-LVAD recipients.

CARD9 knockout ameliorates myocardial dysfunction associated with high fat diet-induced obesity

Obesity is associated with chronic inflammation which plays a critical role in the development of cardiovascular dysfunction. Because the adaptor protein caspase recruitment domain-containing protein 9 (CARD9) in macrophages regulates innate immune responses via activation of pro-inflammatory cytokines, we hypothesize that CARD9 mediates the pro-inflammatory signaling associated with obesity en route to myocardial dysfunction. C57BL/6 wild-type (WT) and CARD9(-/-) mice were fed normal diet (ND, 12% fat) or a high fat diet (HFD, 45% fat) for 5months. At the end of 5-month HFD feeding, cardiac function was evaluated using echocardiography. Cardiomyocytes were isolated and contractile properties were measured. Immunofluorescence was performed to detect macrophage infiltration in the heart. Heart tissue homogenates, plasma, and supernatants from isolated macrophages were collected to measure the concentrations of pro-inflammatory cytokines using ELISA kits. Western immunoblotting analyses were performed on heart tissue homogenates and isolated macrophages to explore the underlying signaling mechanism(s). CARD9 knockout alleviated HFD-induced insulin resistance and glucose intolerance, prevented myocardial dysfunction with preserved cardiac fractional shortening and cardiomyocyte contractile properties. CARD9 knockout also significantly decreased the number of infiltrated macrophages in the heart with reduced myocardium-, plasma-, and macrophage-derived cytokines including IL-6, IL-1β and TNFα. Finally, CARD9 knockout abrogated the increase of p38 MAPK phosphorylation, the decrease of LC3BII/LC3BI ratio and the up-regulation of p62 expression in the heart induced by HFD feeding and restored cardiac autophagy signaling. In conclusion, CARD9 knockout ameliorates myocardial dysfunction associated with HFD-induced obesity, potentially through reduction of macrophage infiltration, suppression of p38 MAPK phosphorylation, and preservation of autophagy in the heart.

Prognostic value of collagen turnover biomarkers in cardiac resynchronization therapy: A subanalysis of the TRUST CRT randomized trial population

BACKGROUND

A substantial proportion of patients do not respond to cardiac resynchronization therapy (CRT). Various echocardiographic and biochemical markers including collagen turnover biomarkers were suggested to predict CRT results. However, pathological significance of collagen turnover biomarkers in CRT remains controversial.

OBJECTIVE

The aim of the present study was to evaluate the relationship between levels of collagen turnover biomarkers (amino-terminal propeptide of procollagen type I and amino-terminal propeptide of procollagen type III [PIIINP]), N-terminal of the prohormone brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein, and matrix metalloproteinases (metalloproteinase-2 and metalloproteinase-9) and echocardiographic response to CRT and clinical outcomes.

METHODS

The study population consisted of patients enrolled in the Triple Site Versus Standard Cardiac Resynchronization Therapy trial. Blood samples were obtained before implantation of a CRT with defibrillator. The levels of PIIINP, amino-terminal propeptide of procollagen type I, metalloproteinase-2, and metalloproteinase-9 were determined using commercially available ELISA kits. High-sensitivity C-reactive protein and NT-proBNP levels were determined in a standard way.

RESULTS

Samples were collected from 74 of 100 enrolled patients. The multivariate logistic regression analysis demonstrated that low PIIINP levels (odds ratio [OR] 3.56; 95% confidence interval [CI] 1.23-10.24; P = .017) and baseline ejection fraction (OR 2.14; 95% CI 1.11-4.11; P = .02) were favorably associated with echocardiographic response. PIIINP and NT-proBNP levels appeared to be independent predictors of all-cause mortality (PIIINP: OR 3.11; 95% CI 1.21-7.89; P = .033; NT-proBNP: OR 2.05; 95% CI 1.11-4.96; P = .039) and risk of major cardiac adverse event (PIIINP: OR 3.56; 95% CI 1.53-9.15; P = .007; NT-proBNP: OR 4.51; 95% CI 1.75-11.6; P = .001). PIIINP levels showed significant additive value in predicting mortality as compared with NT-proBNP levels, but they were not superior to ejection fraction in predicting response. Survival analysis with cutoff values identified by receiver operating characteristic analysis confirmed a significant benefit associated with low baseline PIIINP levels.

CONCLUSION

Low PIIINP levels are associated with favorable echocardiographic response and long-term survival in CRT recipients.

Treatment of dilated cardiomyopathy in rabbits with mesenchymal stem cell transplantation and platelet-rich plasma

Dilated cardiomyopathy (DCM) is a major cause of cardiovascular mortality and morbidity, and there is evidence to suggest that stem cell transplantation may be a viable treatment option for this condition. Therefore, the goal of the present study was to assess myocardial regeneration in rabbits with doxorubicin-induced DCM treated with adipose mesenchymal stem cells (MSC) alone or in combination with platelet-rich plasma (PRP). Twenty New Zealand rabbits received doxorubicin for the induction of DCM and were divided into four groups according to treatment: saline, MSC, PRP and MSC + RP. Treatment agents were injected directly into the left ventricular myocardium following a thoracoscopy. Rabbits were assessed through echocardiographic and electrocardiographic examinations, as well as serum cardiac troponin I measurements at baseline, after the induction of DCM and 15 days after treatment. Animals were euthanased following the last assessment, and hearts were collected for histopathological analyses. The MSC group showed improvements in all parameters assessed, while the PRP group showed significantly impaired heart function. Histopathology of the heart revealed that the MSC group displayed the lowest number of lesions, while rabbits in the MSC + PRP, saline and PRP groups had steadily advancing lesions. These results suggest that MSC transplantation can improve heart function in rabbits with DCM, and underscore the need for further studies of the effects of PRP on the myocardium.

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio are Predictors of Heart Failure

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are inflammatory markers used as prognostic factors in various diseases. The aims of this study were to compare the PLR and the NLR of heart failure (HF) patients with those of age-sex matched controls, to evaluate the predictive value of those markers in detecting HF, and to demonstrate the effect of NLR and PLR on mortality in HF patients during follow-up.

METHODS

This study included 56 HF patients and 40 controls without HF. All subjects underwent transthoracic echocardiography to evaluate cardiac functions. The NLR and the PLR were calculated as the ratio of neutrophil count to lymphocyte count and as the ratio of platelet count to lymphocyte count, respectively. All HF patients were followed after their discharge from the hospital to evaluate mortality, cerebrovascular events, and re-hospitalization.

RESULTS

The NLR and the PLR of HF patients were significantly higher compared to those of the controls (p < 0.01). There was an inverse correlation between the NLR and the left ventricular ejection fraction of the study population (r: -0.409, p < 0.001). The best cut-off value of NLR to predict HF was 3.0, with 86.3% sensitivity and 77.5% specificity, and the best cut-off value of PLR to predict HF was 137.3, with 70% sensitivity and 60% specificity. Only NLR was an independent predictor of mortality in HF patients. A cut-off value of 5.1 for NLR can predict death in HF patients with 75% sensitivity and 62% specificity during a 12.8-month follow-up period on average.

CONCLUSION

NLR and PLR were higher in HF patients than in age-sex matched controls. However, NLR and PLR were not sufficient to establish a diagnosis of HF. NLR can be used to predict mortality during the follow-up of HF patients.

The lymphocyte-to-monocyte ratio: an added value for death prediction in heart failure

BACKGROUND AND AIM

Leukocytes and their subpopulation have been long implicated in the progression of the syndrome of heart failure (HF), especially heart infiltration cells. Previous reports have suggested that they can predict worse outcome in patients with HF, and can also affect the function of other cells and myocardial extracellular matrix remodeling process. However, the lymphocyte-to-monocyte ratio (LMR) and its possible value as prognostic marker have not been evaluated.

METHODS AND RESULTS

A total of 390 patients with acute HF were recruited and followed for 6 months. Their total blood count with leukocyte differential was obtained. Two groups were formed according to the endpoints of HF death and optimal cut-off value of LMR, and were compared. A multivariate Cox-regression model was used to establish the prognostic value with the endpoints of HF and all-cause mortality. Median age of the patients was 78 years and 48.5% of them were men. No major difference was observed between the clinical characteristics of the two groups. Patients who died of HF had significantly higher values of B-type natriuretic peptide and lower values of LMR. Leukocyte and monocyte counts revealed a multivariate-adjusted risk for both endpoints, whereas relative lymphocyte counts had only significant value for all-cause mortality. The multivariate-adjusted hazard ratios for the 6-month HF and all-cause mortality in patients with LMR values < 2.0 were, respectively, 2.28 (95% CI: 1.25-4.15) and 2.39 (95% CI: 1.39-4.10).

CONCLUSION

Our results show that, upon discharge from hospital after an episode of acute HF, a lower value of LMR is independently associated with a higher risk of mortality within 6 months.

A Central Role for Monocyte-Platelet Interactions in Heart Failure

Heart failure (HF) is an increasingly prevalent and costly multifactorial syndrome with high morbidity and mortality rates. The exact pathophysiological mechanisms leading to the development of HF are not completely understood. Several emerging paradigms implicate cardiometabolic risk factors, inflammation, endothelial dysfunction, myocardial fibrosis, and myocyte dysfunction as key factors in the gradual progression from a healthy state to HF. Inflammation is now a recognized factor in disease progression in HF and a therapeutic target. Furthermore, the monocyte-platelet interaction has been highlighted as an important pathophysiological link between inflammation, thrombosis, endothelial activation, and myocardial malfunction. The contribution of monocytes and platelets to acute cardiovascular injury and acute HF is well established. However, their role and interaction in the pathogenesis of chronic HF are not well understood. In particular, the cross talk between monocytes and platelets in the peripheral circulation and in the vicinity of the vascular wall in the form of monocyte-platelet complexes (MPCs) may be a crucial element, which influences the pathophysiology and progression of chronic heart disease and HF. In this review, we discuss the role of monocytes and platelets as key mediators of cardiovascular inflammation in HF, the mechanisms of cell activation, and the importance of monocyte-platelet interaction and complexes in HF pathogenesis. Finally, we summarize recent information on pharmacological inhibition of inflammation and studies of antithrombotic strategies in the setting of HF that can inform opportunities for future work. We discuss recent data on monocyte-platelet interactions and the potential benefits of therapy directed at MPCs, particularly in the setting of HF with preserved ejection fraction.

Respiratory and limb muscle dysfunction in pulmonary arterial hypertension: a role for exercise training?

Respiratory and limb muscle dysfunction is emerging as an important pathophysiological abnormality in pulmonary arterial hypertension (PAH). Muscle abnormalities appear to occur frequently and promote dyspnea, fatigue, and exercise limitation in patients with PAH. Preliminary data suggest that targeted muscle training may be of benefit, although further evidence is required to consolidate these findings into specific recommendations for exercise training in patients with PAH. This article reviews the current evidence on prevalence, risk factors, and implications of respiratory and limb muscle dysfunction in patients with PAH. It also reviews the impact of exercise rehabilitation on morphologic, metabolic, and functional muscle profile and outcomes in PAH. Future research priorities are highlighted.

Increased plasma level of soluble urokinase plasminogen activator receptor is associated with incidence of heart failure but not atrial fibrillation

AIMS

Soluble urokinase plasminogen activator receptor (suPAR) in plasma is a novel inflammatory marker thought to be released from the cell surface of neutrophils, T cells, and macrophages. Other inflammatory markers, mainly acute phase proteins produced in the liver, have been associated with the incidence of heart failure (HF) and atrial fibrillation (AF). We investigated the association between suPAR and incident HF and AF in a population-based cohort.

METHODS AND RESULTS

Soluble urokinase plasminogen activator receptor was measured in 4530 subjects (aged 46–68 years, 61% women), who participated in the Malmö Diet and Cancer study during 1991–1996. Incident cases of HF and AF were identified from the Swedish hospital discharge register during a median follow-up of 16.3 years. During follow-up, 109 subjects (55% men) were diagnosed with new-onset HF and 321 individuals (50% men) with AF. suPAR was significantly associated with increased plasma levels of NT-proBNP (P<0.001). suPAR was significantly associated with incidence of HF [hazard ratio (HR) for the third vs. first tertile 3.33, 95% confidence interval (CI) 1.91–5.81 after adjustment for age and sex; and HR 1.82, 95% CI 1.02–3.27, P for trend 0.018 after adjustment for conventional risk factors and biomarkers]. suPAR was significantly associated with incidence of AF, when adjusted for age and sex (HR 1.40, 95% CI 1.06–1.85). However, this relationship was non-significant after adjustment for conventional risk factors and biomarkers.

CONCLUSION

Soluble urokinase plasminogen activator receptor was associated with increased plasma levels of NT-proBNP and incidence of HF, but not with AF among middle-aged subjects.

Up-regulated TLR4 in cardiomyocytes exacerbates heart failure after long-term myocardial infarction

It remains unclear whether and how cardiomyocytes contribute to the inflammation in chronic heart failure (CHF). We recently reviewed the capacity of cardiomyocytes to initiate inflammation, by means of expressing certain immune receptors such as toll‐like receptors (TLRs) that respond to pathogen‐ and damage‐associated molecular patterns (PAMP and DAMP). Previous studies observed TLR4‐mediated inflammation within days of myocardial infarction (MI). This study examined TLR4 expression and function in cardiomyocytes of failing hearts after 4 weeks of MI in rats. The increases of TLR4 mRNA and proteins, as well as inflammatory cytokine production, were observed in both the infarct and remote myocardium. Enhanced immunostaining for TLR4 was observed in cardiomyocytes but not infiltrating leucocytes. The injection of lentivirus shRNA against TLR4 into the infarcted heart decreased inflammatory cytokine production and improved heart function in vivo. Accordingly, in cardiomyocytes isolated from CHF hearts, increases of TLR4 mRNA and proteins were detected. More robust binding of TLR4 with lipopolysaccharide (LPS), a PAMP ligand for TLR4, and heat shock protein 60 (HSP60), a DAMP ligand for TLR4, was observed in CHF cardiomyocytes under a confocal microscope. The maximum binding capacity (B_max) of TLR4 was increased for LPS and HSP60, whereas the binding affinity (Kd) was not significantly changed. Furthermore, both LPS and HSP60 induced more robust production of inflammatory cytokines in CHF cardiomyocytes, which was reduced by TLR4‐blocking antibodies. We conclude that the expression, ligand‐binding capacity and pro‐inflammatory function of cardiomyocyte TLR4 are up‐regulated after long‐term MI, which promote inflammation and exacerbate heart failure.

Left Ventricular T-Cell Recruitment Contributes to the Pathogenesis of Heart Failure

BACKGROUND

Despite the emerging association between heart failure (HF) and inflammation, the role of T cells, major players in chronic inflammation, has only recently begun to be explored. Whether T-cell recruitment to the left ventricle (LV) participates in the development of HF requires further investigation to identify novel mechanisms that may serve for the design of alternative therapeutic interventions.

METHODS AND RESULTS

Real-time videomicroscopy of T cells from nonischemic HF patients or from mice with HF induced by transverse aortic constriction revealed enhanced adhesion to activated vascular endothelial cells under flow conditions in vitro compared with T cells from healthy subjects or sham mice. T cells in the mediastinal lymph nodes and the intramyocardial endothelium were both activated in response to transverse aortic constriction and the kinetics of LV T-cell infiltration was directly associated with the development of systolic dysfunction. In response to transverse aortic constriction, T cell-deficient mice (T-cell receptor, TCRα(-/-)) had preserved LV systolic and diastolic function, reduced LV fibrosis, hypertrophy and inflammation, and improved survival compared with wild-type mice. Furthermore, T-cell depletion in wild-type mice after transverse aortic constriction prevented HF.

CONCLUSIONS

T cells are major contributors to nonischemic HF. Their activation combined with the activation of the LV endothelium results in LV T-cell infiltration negatively contributing to HF progression through mechanisms involving cytokine release and induction of cardiac fibrosis and hypertrophy. Reduction of T-cell infiltration is thus identified as a novel translational target in HF.

Decompensated Heart Failure Is a Strong Independent Predictor of Functional Outcome After Ischemic Stroke

BACKGROUND

Up to 24% of stroke patients have chronic heart failure. The aim of this study was to determine the frequency and prognostic significance of decompensated heart failure (DHF) in acute stroke patients.

METHODS AND RESULTS

Five hundred sixty-six patients (median age 73 y, 48% men) admitted to the stroke unit within 24 hours after stroke were prospectively included. Diagnosis of DHF was made by a cardiologist during hospitalization. Function outcome was assessed 1 month after stroke onset with the use of a modified Rankin Scale. Unfavorable outcome was defined as scores 3-6. DHF was diagnosed in 17% of patients. Fifty-seven percent of patients with DHF had preserved ejection fraction. Patients with DHF were older and more often female and more frequently suffered from hypertension, diabetes mellitus, atrial fibrillation, and myocardial infarction. They also had more severe neurologic deficit and more often had hyperglycemia, leukocytosis, fever, pneumonia, and renal failure. After multivariate analysis, adjusting for age, stroke severity, atrial fibrillation, myocardial infarction, hyperglycemia, pneumonia, fever, leukocytosis, proteinuria, and reduced ejection fraction, DHF remained an independent predictor of worse outcome (odds ratio 2.34, 95% CI 1.12-4.89; P = .02).

CONCLUSIONS

DHF is a strong independent predictor of poor functional prognosis after ischemic stroke.

Novel Molecular Approaches in Heart Failure: Seven Trans-Membrane Receptors Signaling in the Heart and Circulating Blood Leukocytes

Heart failure (HF) is the result of molecular, cellular, and structural changes induced by cardiac load or injury. A complex network of signaling pathways have been involved in the development and progression of cardiac dysfunction. In this review, we summarize the pivotal role of seven trans-membrane receptors (7TMRs), also called G-protein-coupled receptors (GPCRs), in HF. Moreover, we will discuss the current knowledge on the potential mirroring of 7TMR signaling between circulating blood leukocytes and the heart, and the related future possibilities in the management of HF patients.

Interleukin-6 signaling, soluble glycoprotein 130, and inflammation in heart failure

Both experimental and clinical evidence accumulated over the last couple of decades has linked inflammatory activation to the initiation and progression of chronic heart failure (HF). Circulating levels of inflammatory mediators are associated with cardiac function and inform risk prediction in patients, but the effect of anti-inflammatory therapy in HF remains uncertain. Interleukin (IL)-6 type cytokines are central to the inflammatory response, and convey their signals through the ubiquitously expressed glycoprotein (gp) 130 receptor subunit. IL-6-type/gp130 signaling therefore represents an inflammatory nexus, with inherent potential for disease modification. This review focuses on the current knowledge of IL-6/gp130 signaling in relation to HF, with a particular emphasis on the role of soluble gp130 (sgp130), a signaling pathway modulator. Biological aspects of sgp130 and IL-6 signaling are discussed, as are potential novel therapeutic approaches to modulate this central inflammatory signaling pathway.

Comparison of whole blood and peripheral blood mononuclear cell gene expression for evaluation of the perioperative inflammatory response in patients with advanced heart failure

BACKGROUND

Heart failure (HF) prevalence is increasing in the United States. Mechanical Circulatory Support (MCS) therapy is an option for Advanced HF (AdHF) patients. Perioperatively, multiorgan dysfunction (MOD) is linked to the effects of device implantation, augmented by preexisting HF. Early recognition of MOD allows for better diagnosis, treatment, and risk prediction. Gene expression profiling (GEP) was used to evaluate clinical phenotypes of peripheral blood mononuclear cells (PBMC) transcriptomes obtained from patients' blood samples. Whole blood (WB) samples are clinically more feasible, but their performance in comparison to PBMC samples has not been determined.

METHODS

We collected blood samples from 31 HF patients (57±15 years old) undergoing cardiothoracic surgery and 7 healthy age-matched controls, between 2010 and 2011, at a single institution. WB and PBMC samples were collected at a single timepoint postoperatively (median day 8 postoperatively) (25-75% IQR 7-14 days) and subjected to Illumina single color Human BeadChip HT12 v4 whole genome expression array analysis. The Sequential Organ Failure Assessment (SOFA) score was used to characterize the severity of MOD into low (≤ 4 points), intermediate (5-11), and high (≥ 12) risk categories correlating with GEP.

RESULTS

Results indicate that the direction of change in GEP of individuals with MOD as compared to controls is similar when determined from PBMC versus WB. The main enriched terms by Gene Ontology (GO) analysis included those involved in the inflammatory response, apoptosis, and other stress response related pathways. The data revealed 35 significant GO categories and 26 pathways overlapping between PBMC and WB. Additionally, class prediction using machine learning tools demonstrated that the subset of significant genes shared by PBMC and WB are sufficient to train as a predictor separating the SOFA groups.

CONCLUSION

GEP analysis of WB has the potential to become a clinical tool for immune-monitoring in patients with MOD.

Temporal and gefitinib-sensitive regulation of cardiac cytokine expression via chronic β-adrenergic receptor stimulation

Chronic stimulation of β-adrenergic receptors (βAR) can promote survival signaling via transactivation of epidermal growth factor receptor (EGFR) but ultimately alters cardiac structure and contractility over time, in part via enhanced cytokine signaling. We hypothesized that chronic catecholamine signaling will have a temporal impact on cardiac transcript expression in vivo, in particular cytokines, and that EGFR transactivation plays a role in this process. C57BL/6 mice underwent infusion with vehicle or isoproterenol (Iso)±gefitinib (Gef) for 1 or 2 wk. Cardiac contractility decreased following 2 wk of Iso treatment, while cardiac hypertrophy, fibrosis, and apoptosis were enhanced at both timepoints. Inclusion of Gef preserved contractility, blocked Iso-induced apoptosis, and prevented hypertrophy at the 2-wk timepoint, but caused fibrosis on its own. RNAseq analysis revealed hundreds of cardiac transcripts altered by Iso at each timepoint with subsequent RT-quantitative PCR validation confirming distinct temporal patterns of transcript regulation, including those involved in cardiac remodeling and survival signaling, as well as numerous cytokines. Although Gef infusion alone did not significantly alter cytokine expression, it abrogated the Iso-mediated changes in a majority of the βAR-sensitive cytokines, including CCL2 and TNF-α. Additionally, the impact of βAR-dependent EGFR transactivation on the acute regulation of cytokine transcript expression was assessed in isolated cardiomyocytes and in cardiac fibroblasts, where the majority of Iso-dependent, and EGFR-sensitive, changes in cytokines occurred. Overall, coincident with changes in cardiac structure and contractility, βAR stimulation dynamically alters cardiac transcript expression over time, including numerous cytokines that are regulated via EGFR-dependent signaling.

CXCR4 Antagonist TG-0054 Mobilizes Mesenchymal Stem Cells, Attenuates Inflammation, and Preserves Cardiac Systolic Function in a Porcine Model of Myocardial Infarction

Interaction between chemokine stromal cell-derived factor 1 and the CXC chemokine receptor 4 (CXCR4) governs the sequestration and mobilization of bone marrow stem cells. We investigated the therapeutic potential of TG-0054, a novel CXCR4 antagonist, in attenuating cardiac dysfunction after myocardial infarction (MI). In miniature pigs (minipigs), TG-0054 mobilized CD34(+)CXCR4(+), CD133(+)CXCR4(+), and CD271(+)CXCR4(+) cells into peripheral circulation. After isolation and expansion, TG-0054-mobilized CD271(+) cells were proved to be mesenchymal stem cells (designated CD271-MSCs) since they had trilineage differentiation potential, surface markers of MSCs, and immunosuppressive effects on allogeneic lymphocyte proliferation. MI was induced in 22 minipigs using balloon occlusion of the left anterior descending coronary artery, followed by intravenous injections of 2.85 mg/kg of TG-0054 or saline at 3 days and 7 days post-MI. Serial MRI analyses revealed that TG-0054 treatment prevented left ventricular (LV) dysfunction at 12 weeks after MI (change of LV ejection fraction from baseline, -1.0 ± 6.2% in the TG-0054 group versus -7.9 ± 5.8% in the controls). The preserved cardiac function was accompanied by a significant decrease in the myocardial expression of TNF-α, IL-1β, and IL-6 at 7 days post-MI. Moreover, the plasma levels of TNF-α, IL-1β, and IL-6 were persistently suppressed by the TG-0054 treatment. Infusion of TG-0054-mobilized CD271-MSCs reduced both myocardial and plasma cytokine levels in a pattern, which is temporally correlated with TG-0054 treatment. This study demonstrated that TG-0054 improves the impaired LV contractility following MI, at least in part, by mobilizing MSCs to attenuate the postinfarction inflammation. This insight may facilitate exploring novel stem cell-based therapy for treating post-MI heart failure.

Inflammation and future risk of symptomatic heart failure in patients with stable coronary artery disease

BACKGROUND

Heart failure (HF) carries poor prognosis in coronary artery disease (CAD) patients despite advances in therapy. Inflammation predicts recurrent cardiovascular events in CAD patients. It is unknown whether increased levels of inflammatory markers are associated with incident HF in these patients.

AIM

The aims of this study were to evaluate the association between inflammatory markers and future HF risk in patients with stable CAD and to explore possible mediation by myocardial infarction (MI).

METHODS

The study comprised 2,945 patients with stable CAD without HF at baseline during a median follow-up of 7.9 years. Inflammatory baseline markers were the basis of this study.

RESULTS

Heart failure was diagnosed in 508 patients (17.2%). Patients who developed HF were older and had more often previous MI, diabetes, hypertension, and peripheral vascular disease. Baseline levels of C-reactive protein (CRP), fibrinogen, and white blood cells (WBCs) were significantly higher in patients who developed HF compared with those who did not. Age-adjusted incident HF rates were related to elevated baseline inflammatory markers in a dose-response manner. Adjusting for multiple confounders, the HF hazard ratios were 1.38 (95% CI 1.11-1.72), 1.33 (95% CI 1.07-1.66), and 1.36 (95% CI 1.10-1.68) for the third tertiles of CRP, fibrinogen, and WBC levels, respectively. Hazard ratio for the fifth quintile of a combined "inflammation score" was 1.83 (95% CI 1.40-2.39). Mediation by MI preceding the HF onset during follow-up accounted for 10.4%, 10.8%, and 8.6% of the association of subsequent HF with CRP, fibrinogen, and WBC, respectively.

CONCLUSIONS

Increased levels of CRP, fibrinogen, and WBC are independently related to the incidence of HF in patients with stable CAD.

The mononuclear phagocyte system in homeostasis and disease: a role for heme oxygenase-1

SIGNIFICANCE

Heme oxygenase-1 (HO-1) is a potential therapeutic target in many diseases, especially those mediated by oxidative stress and inflammation. HO-1 expression appears to regulate the homeostatic activity and distribution of mononuclear phagocytes (MP) in lymphoid tissue under physiological conditions. It also regulates the ability of MP to modulate the inflammatory response to tissue injury.

RECENT ADVANCES

The induction of HO-1 within MP-particularly macrophages and dendritic cells-modulates the effector functions that they acquire after activation. These effector functions include cytokine production, surface receptor expression, maturation state, and polarization toward a pro- or anti-inflammatory phenotype. The importance of HO-1 in MP is emphasized by their expression of specific receptors that primarily function to ingest heme-containing substrate and deliver it to HO-1.

CRITICAL ISSUES

MP are the first immunological responders to tissue damage. They critically affect the outcome of injury to many organ systems, yet few therapies are currently available to specifically target MP during disease pathogenesis. Elucidation of the role of HO-1 expression in MP may help to direct broadly applicable therapies to clinical use that are based on the immunomodulatory capabilities of HO-1.

FUTURE DIRECTIONS

Unraveling the complexities of HO-1 expression specifically within MP will more completely define how HO-1 provides cytoprotection in vivo. The use of models in which HO-1 expression is specifically modulated in bone marrow-derived cells will allow for a more complete characterization of its immunoregulatory properties.

Mendelian forms of structural cardiovascular disease

Clinical and molecular genetics are inextricably linked. In the last two decades genetic studies have revealed the causes of several forms of structural heart disease. Recent work is extending the insights from inherited arrhythmias and cardiomyopathies to other forms of heart disease. In this review we outline the current state of the art for the genetics of adult structural heart disease, in particular the cardiomyopathies, valvular heart disease and aortic disease. The general approaches are described with a focus on clinical relevance, while potential areas for imminent innovation in diagnosis and therapeutics are highlighted.

The effect of rosuvastatin on inflammation, matrix turnover and left ventricular remodeling in dilated cardiomyopathy: a randomized, controlled trial

Background

Dilated cardiomyopathy is characterized by left ventricular dilatation and dysfunction. Inflammation and adverse remodeling of the extracellular matrix may be involved in the pathogenesis. Statins reduce levels of low density lipoprotein cholesterol, but may also attenuate inflammation and affect matrix remodeling. We hypothesized that treatment with rosuvastatin would reduce or even reverse left ventricular remodeling in dilated cardiomyopathy.

Materials and Methods

In this multicenter, randomized, double blind, placebo-controlled study, 71 patients were randomized to 10 mg of rosuvastatin or matching placebo. Physical examination, blood sampling, echocardiography and cardiac magnetic resonance imaging were performed at baseline and at six months’ follow-up. The pre-specified primary end point was the change in left ventricular ejection fraction from baseline to six months.

Results

Over all, left ventricular ejection fraction improved 5 percentage points over the duration of the study, but there was no difference in the change in left ventricular ejection fraction between patients allocated to rosuvastatin and those allocated to placebo. Whereas serum low density lipoprotein cholesterol concentration fell significantly in the treatment arm, rosuvastatin did not affect plasma or serum levels of a wide range of inflammatory variables, including C-reactive protein. The effect on markers of extracellular matrix remodeling was modest.

Conclusion

Treatment with rosuvastatin does not improve left ventricular ejection fraction in patients with dilated cardiomyopathy.

Trial Registration

ClinicalTrials.gov NCT00505154

Striated muscle activator of Rho signaling is required for myotube survival but does not influence basal protein synthesis or degradation

Skeletal muscle mass is regulated by sensing and transmitting extracellular mechanical stress signals to intracellular signaling pathways controlling protein synthesis and degradation. Striated muscle activator of Rho signaling (STARS) is a muscle-specific actin-binding protein that is sensitive to extracellular stress signals. STARS stimulates actin polymerization and influences serum response factor (SRF) and peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α transcription of genes involved in muscle growth, structure, and contraction. The role of STARS in skeletal muscle cells is not well understood. This study investigated whether STARS influenced C2C12 myotube growth by regulating protein synthesis and degradation. The influence of STARS on Pgc-1α, Srf, and Errα mRNA levels, as well as several of their downstream targets involved in muscle cell growth, contraction, and metabolism, was also investigated. STARS overexpression increased actin polymerization, with no effect on protein synthesis, protein degradation, or Akt phosphorylation. STARS overexpression increased Pgc-1α, Srf, Ckmt2, Cpt-1β, and Mhc1 mRNA. STARS knockdown reduced actin polymerization and increased cell death and dead cell protease activity. It also increased markers of inflammation (Casp1, Il-1β, and Mcp-1), regeneration (Socs3 and Myh8), and fast myosin isoforms (Mhc2a and Mhc2x). We show for the first time in muscle cells that STARS overexpression increases actin polymerization and shifts the muscle cell to a more oxidative phenotype. The suppression of STARS causes cell death and increases markers of necrosis, inflammation, and regeneration. As STARS levels are suppressed in clinical models associated with increased necrosis and inflammation, such as aging and limb immobilization, rescuing STARS maybe a future therapeutic strategy to maintain skeletal muscle function and attenuate contraction-induced muscle damage.

Persistence of apoptosis and inflammatory responses in the heart and bone marrow of mice following whole-body exposure to ²⁸Silicon (²⁸Si) ions

It has been well established that the bone marrow (BM) is a radiosensitive tissue, but the radiosensitivity of the heart is poorly understood. In this study, we investigated the comparative effects of ²⁸Silicon (²⁸Si) ions (one type of heavy ion found in space) on tissue from the heart and the BM of exposed mice. We gave adult male CBA/CaJ mice a whole-body exposure to a total dose of 0, 0.1, 0.25, or 0.5 Gy of 300 MeV/nucleon (n) ²⁸Si ions, using a fractionated schedule (two exposures, 15 days apart that totaled each selected dose). The heart and BM were collected from 5 mice per treatment group at various times up to 6 months post-irradiation. In each mouse, we obtained tissue lysates from the heart and from the total population of BM cells for measuring the levels of cleaved poly (ADP-ribose) polymerase (cleaved PARP, a marker of apoptotic cell death) and the levels of activated nuclear factor-kappa B (NF-κB) and selected NF-κB-regulated cytokines known to be involved in inflammatory responses. Our data showed that, up to 6 months post-irradiation, the levels of apoptotic cell death and inflammatory responses in tissues from the heart and BM collected from exposed mice were statistically higher than those in sham controls. Hence, these findings are suggestive of chronic apoptotic cell death and inflammation in both tissues after exposure to ²⁸Si ions. In summary, our data are indicative of a possible association between exposure to ²⁸Si ions during space flight and long-term health risk.

IL-18 stimulates B-type natriuretic peptide synthesis by cardiomyocytes in vitro and its plasma levels correlate with B-type natriuretic peptide in non-overloaded acute heart failure patients

BACKGROUND

An altered IL-18 pathway in heart failure (HF) has recently been described and this cytokine was shown to be of clinical and prognostic utility. Cardiomyocytes are a target of this cytokine which exerts inflammatory, hypertrophic, and profibrotic activities. B-type natriuretic peptide is a cardiac hormone produced in response to cardiac filling to regulate cardiovascular homeostasis. The aim of the study was to verify the ability of IL-18 to induce B-type natriuretic peptide synthesis in vitro and to analyse the relationship between these two molecules in plasma in vivo from acute HF patients.

METHODS AND RESULTS

We demonstrated the ability of IL-18 to directly stimulate a murine cardiomyocyte cell line to express the B-type natriuretic peptide gene, synthesize the relative protein through a PI3K-AKT-dependent transduction, and induce a cell secretory phenotype with B-type natriuretic peptide release. A correlation between IL-18 and B-type natriuretic peptide plasma levels was found in non-overloaded acute HF patients, and in subgroups of acute HF patients with diabetes and coronary artery disease. Acute HF patients with renal failure had significantly higher IL-18 plasma levels than patients without. IL-18 plasma levels were correlated with C-reactive protein plasma levels.

CONCLUSIONS

This study provides the first evidence of the ability of IL-18 to induce B-type natriuretic peptide synthesis in vitro and outlines the relationship between the two molecules in acute HF patients with an ongoing inflammatory status.

Aerobic exercise improves the inflammatory profile correlated with cardiac remodeling and function in chronic heart failure rats

OBJECTIVE

The aim of the present study was to evaluate the effect of 8 weeks of aerobic exercise training on cardiac functioning and remodeling and on the plasma levels of inflammatory cytokines in chronic heart failure rats.

METHODS

Wistar rats were subjected to myocardial infarction or sham surgery and assigned to 4 groups: chronic heart failure trained (n=7), chronic heart failure sedentary (n=6), sham trained (n=8) and sham sedentary (n=8). Four weeks after the surgical procedures, the rats were subjected to aerobic training in the form of treadmill running (50 min/day, 5 times per week, 16 m/min). At the end of 8 weeks, the rats were placed under anesthesia, the hemodynamic variables were recorded and blood samples were collected. Cardiac hypertrophy was evaluated using the left ventricular weight/body weight ratio, and the collagen volume fraction was assessed using histology.

RESULTS

The chronic heart failure trained group showed a reduction in left ventricular end-diastolic pressure, a lower left ventricular weight/body weight ratio and a lower collagen volume fraction compared with the chronic heart failure sedentary group. In addition, exercise training reduced the plasma levels of TNF-α and IL-6 and increased the plasma level of IL-10.

CONCLUSION

An 8-week aerobic exercise training program improved the inflammatory profile and cardiac function and attenuated cardiac remodeling in chronic heart failure rats.

Increased levels of plasma soluble Sema4D in patients with heart failure

Semaphorin 4D (Sema4D/CD100) is a 150-kDa transmembrane glycoprotein expressed by platelets and T-cells. When these cells are activated, Sema4D is cleaved proteolytically, generating a biologically active 120-kDa fragment (soluble Sema4D) capable of targeting receptors on platelets, B-cells, endothelial cells and tumor cells. However, its plasma levels and significance in heart failure (HF) have not been reported. In this study, we established an ELISA and detected soluble Sema4D in human plasma. In healthy controls, plasma Sema4D levels were higher in men than women (5.15±3.30 ng/mL, n = 63, vs. 4.19±2.39 ng/mL, n = 63, P<0.05). In HF patients, plasma Sema4D levels were significantly higher than those in healthy controls (8.94±5.89 ng/mL, n = 157 vs. 4.67±2.99 ng/mL, n = 126, P<0.0001) with the highest levels being in HF patients with diabetes mellitus (DM) (10.45±5.76 ng/mL, n = 40). We also found that there was a higher percentage of Sema4D(high) CD3(+) (P<0.01), CD4(+) (P<0.001), and CD8(+) (P<0.01) T-cells in samples from HF patients, but no changes in Sema4D expression levels in B cells and platelets. Therefore, our investigation shows that plasma Sema4D levels are increased in HF patients, especially in those who also have diabetes. There was an accompanying increase in the Sema4D(high) population of T-cells, suggesting a potential role of these T-cells in heart failure.

Cardiac asthma: new insights into an old disease

Cardiac asthma has been defined as wheezing, coughing and orthopnea due to congestive heart failure. The clinical distinction between bronchial asthma and cardiac asthma can be straight forward, except in patients with chronic lung disease coexisting with left heart disease. Pulmonary edema and pulmonary vascular congestion have been thought to be the primary causes of cardiac asthma but most patients have a poor response to diuretics. There appears to be limited effectiveness of classical asthma medications like bronchodilators or corticosteroids in treating cardiac asthma. Evidence suggests that circulating inflammatory factors and tissue growth factors also lead to airway obstruction suggesting the possibility of developing novel therapies.

Chronic exercise leads to antiaggregant, antioxidant and anti-inflammatory effects in heart failure patients

BACKGROUND

Heart failure (HF) patients are at an increased risk of thrombotic events. Here, we investigated the effects of exercise training on platelet function and factors involved in its modulation in HF.

DESIGN AND METHODS

Thirty HF patients were randomized to 6 months of supervised exercise training or to a control group that remained sedentary. Exercise training consisted of 30 min of moderate-intensity treadmill exercise, followed by resistance and stretching exercises, performed three times a week. Blood was collected before and after the intervention for platelet and plasma obtainment.

RESULTS

Peak VO2 increased after exercise training (18.0 ± 2.2 vs. 23.8 ± 0.5 mlO2/kg/min; p < 0.05). Exercise training reduced platelet aggregation induced by both collagen and ADP (approximately -6%; p < 0.05), as well as platelet nitric oxide synthase activity (0.318 ± 0.030 vs. 0.250 ± 0.016 pmol/10(8) cells; p < 0.05). No difference in the above-mentioned variables were observed in the control group. No significant difference was observed in intraplatelet cyclic guanosine monophosphate levels among groups. There was a significant increase in the activity of the antioxidant enzymes superoxide dismutase and catalase in plasma and platelets, resulting in a decrease in both lipid and protein oxidative damage. Systemic levels of the inflammatory markers C-reactive protein, fibrinogen, and tumour necrosis factor α were also reduced in HF after training.

CONCLUSIONS

Our results suggest that regular exercise training is a valuable adjunct to optimal medical management of HF, reducing platelet aggregation via antioxidant and anti-inflammatory effects, and, therefore, reducing the risk of future thrombotic events.