Pathophysiological correlates of increased serum tumor necrosis factor in patients with congestive heart failure. Relation to nitric oxide-dependent vasodilation in the forearm circulation

Molecular Mechanisms Underlying Heart Failure and Their Therapeutic Potential

Heart failure (HF) is a prominent fatal cardiovascular disorder afflicting 3.4% of the adult population despite the advancement of treatment options. Therefore, a better understanding of the pathogenesis of HF is essential for exploring novel therapeutic strategies. Hypertrophy and fibrosis are significant characteristics of pathological cardiac remodeling, contributing to HF. The mechanisms involved in the development of cardiac remodeling and consequent HF are multifactorial, and in this review, the key underlying mechanisms are discussed. These have been divided into the following categories thusly: (i) mitochondrial dysfunction, including defective dynamics, energy production, and oxidative stress; (ii) cardiac lipotoxicity; (iii) maladaptive endoplasmic reticulum (ER) stress; (iv) impaired autophagy; (v) cardiac inflammatory responses; (vi) programmed cell death, including apoptosis, pyroptosis, and ferroptosis; (vii) endothelial dysfunction; and (viii) defective cardiac contractility. Preclinical data suggest that there is merit in targeting the identified pathways; however, their clinical implications and outcomes regarding treating HF need further investigation in the future. Herein, we introduce the molecular mechanisms pivotal in the onset and progression of HF, as well as compounds targeting the related mechanisms and their therapeutic potential in preventing or rescuing HF. This, therefore, offers an avenue for the design and discovery of novel therapies for the treatment of HF.

Combination of Anti-CD40 and Anti-CD40L Antibodies as Co-Stimulation Blockade in Preclinical Cardiac Xenotransplantation

The blockade of the CD40/CD40L immune checkpoint is considered essential for cardiac xenotransplantation. However, it is still unclear which single antibody directed against CD40 or CD40L (CD154), or which combination of antibodies, is better at preventing organ rejection. For example, the high doses of antibody administered in previous experiments might not be feasible for the treatment of humans, while thrombotic side effects were described for first-generation anti-CD40L antibodies. To address these issues, we conducted six orthotopic pig-to-baboon cardiac xenotransplantation experiments, combining a chimeric anti-CD40 antibody with an investigational long-acting PASylated anti-CD40L Fab fragment. The combination therapy effectively resulted in animal survival with a rate comparable to a previous study that utilized anti-CD40 monotherapy. Importantly, no incidence of thromboembolic events associated with the administration of the anti-CD40L PAS-Fab was observed. Two experiments failed early because of technical reasons, two were terminated deliberately after 90 days with the baboons in excellent condition and two were extended to 120 and 170 days, respectively. Unexpectedly, and despite the absence of any clinical signs, histopathology revealed fungal infections in all four recipients. This study provides, for the first time, insights into a combination therapy with anti-CD40/anti-CD40L antibodies to block this immune checkpoint.

The Impact of the Neutrophil-to-Lymphocyte Ratio on In-Hospital Outcomes in Patients With Acute ST-Segment Elevation Myocardial Infarction

Introduction The neutrophil-to-lymphocyte ratio (NLR) is a significant predictor of cardiovascular diseases, influencing their progression and prognosis. The exact role of the NLR in acute ST-segment elevation myocardial infarction (STEMI) is unclear. We investigated the possible association between peak NLR values within the first three days after STEMI onset and in-hospital outcomes in patients undergoing primary percutaneous coronary intervention (PCI). Methods This retrospective study included 641 patients who were diagnosed with acute STEMI and treated with primary PCI for 18 months at Dr. Siyami Ersek Hospital. The NLR was calculated using the maximum values obtained during the first three days after admission. The patients were divided into quartiles according to their NLR values for further analysis of potential complications during and after hospitalization, up to a follow-up period of three months. Results Significant differences were found in factors such as age, body mass index (BMI), and length of hospital stay among these groups. Specifically, we found that in-hospital mortality rates were significantly higher in the Q4 group, and there were variations in target vessel revascularization (TVR) rates, major adverse cardiac events (MACE) rates, and other clinical outcomes. Some parameters, such as reinfarction rates and certain procedural outcomes, did not show significant differences among the groups. However, despite the differences, most of the patients achieved successful outcomes after PCI, with the best results in the low NLR group and the worst results in the high NLR group. Conclusion Higher NLR values were associated with a higher risk of unfavorable outcomes during hospitalization.

The genetic interactions between non-alcoholic fatty liver disease and cardiovascular diseases

The ongoing debate on whether non-alcoholic fatty liver disease (NAFLD) is an active contributor or an innocent bystander in the development of cardiovascular disease (CVD) has sparked interests in understanding the common mediators between the two biologically distinct entities. This comprehensive review identifies and curates genetic studies of NAFLD overlapping with CVD, and describes the colinear as well as opposing correlations between genetic associations for the two diseases. Here, CVD described in relation to NAFLD are coronary artery disease, cardiomyopathy and atrial fibrillation. Unique findings of this review included certain NAFLD susceptibility genes that possessed cardioprotective properties. Moreover, the complex interactions of genetic and environmental risk factors shed light on the disparity in genetic influence on NAFLD and its incident CVD. This serves to unravel NAFLD-mediated pathways in order to reduce CVD events, and helps identify targeted treatment strategies, develop polygenic risk scores to improve risk prediction and personalise disease prevention.

Persistent Endothelial Dysfunction in Coronavirus Disease-2019 Survivors Late After Recovery

Background

Coronavirus disease 2019 (COVID-19) can result in an endothelial dysfunction in acute phase. However, information on the late vascular consequences of COVID-19 is limited.

Methods

Brachial artery flow-mediated dilation (FMD) examination were performed, and inflammatory biomarkers were assessed in 86 survivors of COVID-19 for 327 days (IQR 318–337 days) after recovery. Comparisons were made with 28 age-matched and sex-matched healthy controls and 30 risk factor-matched patients.

Results

Brachial artery FMD was significantly lower in the survivors of COVID-19 than in the healthy controls and risk factor-matched controls [median (IQR) 7.7 (5.1–10.7)% for healthy controls, 6.9 (5.5–9.4)% for risk factor-matched controls, and 3.5(2.2–4.6)% for COVID-19, respectively, p < 0.001]. The FMD was lower in 25 patients with elevated tumor necrosis factor (TNF)-α [2.7(1.2–3.9)] than in 61 patients without elevated TNF-α [3.8(2.6–5.3), p = 0.012]. Furthermore, FMD was inversely correlated with serum concentration of TNF-α (r = −0.237, p = 0.007).

Conclusion

Survivors of COVID-19 have a reduced brachial artery FMD, which is inversely correlated with increased serum concentration of TNF-α. Prospective studies on the association of endothelial dysfunction with long-term cardiovascular outcomes, especially the early onset of atherosclerosis, are warranted in survivors of COVID-19.

Biomarkers in the clinical management of patients with atrial fibrillation and heart failure

Atrial fibrillation (AF) and heart failure (HF) are two cardiovascular diseases with an increasing prevalence worldwide. These conditions share common pathophysiologiesand frequently co-exit. In fact, the occurrence of either condition can 'cause' the development of the other, creating a new patient group that demands different management strategies to that if they occur in isolation. Regardless of the temproral association of the two conditions, their presence is linked with adverse cardiovascular outcomes, increased rate of hospitalizations, and increased economic burden on healthcare systems. The use of low-cost, easily accessible and applicable biomarkers may hasten the correct diagnosis and the effective treatment of AF and HF. Both AF and HF effect multiple physiological pathways and thus a great number of biomarkers can be measured that potentially give the clinician important diagnostic and prognostic information. These will then guide patient centred therapeutic management. The current biomarkers that offer potential for guiding therapy, focus on the physiological pathways of miRNA, myocardial stretch and injury, oxidative stress, inflammation, fibrosis, coagulation and renal impairment. Each of these has different utility in current clinincal practice.

Metabolic Inflammation-A Role for Hepatic Inflammatory Pathways as Drivers of Comorbidities in Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) is a global and growing health concern. Emerging evidence points toward metabolic inflammation as a key process in the fatty liver that contributes to multiorgan morbidity. Key extrahepatic comorbidities that are influenced by NAFLD are type 2 diabetes, cardiovascular disease, and impaired neurocognitive function. Importantly, the presence of nonalcoholic steatohepatitis and advanced hepatic fibrosis increase the risk for systemic comorbidity in NAFLD. Although the precise nature of the crosstalk between the liver and other organs has not yet been fully elucidated, there is emerging evidence that metabolic inflammation-in part, emanating from the fatty liver-is the engine that drives cellular dysfunction, cell death, and deleterious remodeling within various body tissues. This review describes several inflammatory pathways and mediators that have been implicated as links between NAFLD and type 2 diabetes, cardiovascular disease, and neurocognitive decline.

Biomarker profile in stable Fontan patients

BACKGROUND

As the population of adults with congenital heart disease (CHD) grows, cardiologists continue to encounter patients with complex anatomies that challenge the standard treatment of care. Single ventricle Fontan palliated patients are the most complex within CHD, with a high morbidity and mortality burden. Factors driving this early demise are largely unknown.

METHODS AND RESULTS

We analyzed biomarker expression in 44 stable Fontan outpatients (29.2 ± 10.7 years, 68.2% female) seen in the outpatient Emory Adult Congenital Heart Center and compared them to 32 age, gender and race matched controls. In comparison to controls, Fontan patients had elevated levels of multiple cytokines within the inflammatory pathway including Tumor Necrosis Factor-α (TNF-α) (p < 0.001), Interleukin-6 (IL-6) (p < 0.011), Growth Derived Factor-15 (GDF-15) (p < 0.0001), β2-macroglobulin, (p = 0.0006), stem cell mobilization: Stromal Derived Factor-1∝ (SDF-1α) (p = 0.006), extracellular matrix turnover: Collagen IV (p < 0.0001), neurohormonal activation: Renin (p < 0.0001), renal dysfunction: Cystatin C (p < 0.0001) and Urokinase Receptor (uPAR) (p = 0.022), cardiac injury: Troponin-I (p < 0.0004) and metabolism: Adiponectin (p = 0.0037). Within 1 year of enrollment 50% of Fontan patients had hospitalizations, arrhythmias or worsening hepatic function. GDF-15 was significantly increased in Fontan patients with clinical events (p < 0.0001). In addition, GDF-15 moderately correlated with longer duration of Fontan (r = 0.55, p = 0.01) and was elevated in atriopulmonary (AP) Fontan circulation. Finally, in a multivariate model, VEGF-D and Collagen IV levels were found to be associated with a change in MELDXI, a marker of liver dysfunction.

CONCLUSION

Multiple clinical and molecular biomarkers are upregulated in Fontan patients, suggesting a state of chronic systemic dysregulation.

Outcomes of patients with anemia and renal dysfunction in hospitalized heart failure with preserved ejection fraction (from the CN-HF registry)

Background

Although a large number of studies on heart failure with reduced ejection fraction (HFrEF) have found that anemia and renal dysfunction (RD) independently predicted poor outcomes, there are still few reports on patients with heart failure with preserved ejection fraction (HFpEF).

Methods

Clinical data of HFpEF patients registered in the China National Heart Failure Registration Study (CN-HF) were evaluated and the clinical features of patients with or without anemia/RD were compared to explore the impact of anemia and RD on all-cause mortality and all-cause re-hospitalization.

Results

1604 patients with HFpEF were enrolled, the prevalence of anemia was 51.0%. Although anemia was associated with increased risk of all-cause mortality and all-cause re-hospitalization in univariate COX regression (p < 0.05), multivariate COX model confirmed that anemia was not independently associated with all-cause mortality [hazard ratio (HR) 1.14, 95% confidence interval (CI) 0.85–1.52, p = 0.386] and all-cause re-hospitalization (HR 1.13, 95% CI 0.96–1.33, p = 0.152). Similarly, RD was not an independent predictor of all-cause mortality (HR 1.18, 95% CI 0.88–1.57, p = 0.269) and all-cause re-hospitalization (HR 0.94, 95% CI 0.79–1.12, p = 0.488) as assessed in the adjusted COX regression model. The interaction between RD and anemia on end-points events was also not statistically significant. However, anemia was associated with increased all-cause re-hospitalization in patients with New York Heart Association (NYHA) class III-IV.

Conclusions

In patients with HFpEF from CN-HF registry, anemia was common, but was not an independent predictor of all-cause mortality and all-cause re-hospitalization, except for the all-cause re-hospitalization in patients with NYHA class III-IV.

Clinical Trial Registration: http://www.clinicaltrials.gov/ct2/home; ID: NCT02079428.

Sarcopenia and Endothelial Function in Patients With Chronic Heart Failure: Results From the Studies Investigating Comorbidities Aggravating Heart Failure (SICA-HF)

OBJECTIVES

Skeletal muscle wasting, also known as sarcopenia, has recently been identified as a serious comorbidity in patients with heart failure (HF). We aimed to assess the impact of sarcopenia on endothelial dysfunction in patients with HF with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF).

DESIGN

Cross-sectional study.

SETTING

Ambulatory patients with HF were recruited at Charité Medical School, Campus Virchow-Klinikum, Berlin, Germany.

PARTICIPANTS

We assessed peripheral blood flow (arm and leg) in 228 patients with HF and 32 controls who participated in the Studies Investigating Comorbidities Aggravating HF (SICA-HF).

MEASUREMENTS

The appendicular skeletal muscle mass of the arms and the legs combined was assessed by dual energy x-ray absorptiometry (DEXA). Sarcopenia was defined as the appendicular muscle mass two standard deviations below the mean of a healthy reference group of adults aged 18 to 40 years, as suggested for the diagnosis of muscle wasting in healthy aging. All patients underwent a 6-minute walk test and spiroergometry testing. Forearm and leg blood flow were measured by venous occlusion plethysmography. Peak blood flow was assessed after a period of ischemia in the limbs to test endothelial function.

RESULTS

Sarcopenia was identified in 37 patients (19.5%). Patients with sarcopenia presented with lower baseline forearm blood flow (2.30 ± 1.21 vs. 3.06 ± 1.49 vs. 4.00 ± 1.66 mL min^-1 100 mL^-1; P = .02) than those without sarcopenia or controls. The group of patients with sarcopenia showed similar baseline leg blood flow (2.06 ± 1.62 vs. 2.39 ± 1.39 mL min^-1 100 mL^-1; P = .11) to those without but lower values when compared to controls (2.06 ± 1.62 vs. 2.99 ± 1.28 mL min^-1 100 mL^-1; P = .03). In addition, patients with and without sarcopenia presented with lower peak flow in the forearm when compared to controls (18.37 ± 7.07 vs. 22.19 ± 8.64 vs. 33.63 ± 8.57 mL min^-1 100 mL^-1; P < .001). A similar result was observed in the leg (10.89 ± 5.61 vs. 14.66 ± 7.19 vs. 21.37 ± 13.16 mL min^-1 100 mL^-1; P < .001). Peak flow in the forearm showed a significant correlation with exercise capacity (relative peak VO₂: R = 0.47; P < .001; absolute peak VO₂: R = 0.35; P < .001; and 6-min walk distance: R = 0.20; P < .01). Similar correlations were observed between peak flow in the leg and exercise capacity (absolute peak VO₂: R = 0.42, P < .001; relative peak VO₂: R = 0.41, P < .001; and 6-min walk test: R = 0.33; P < .001). Logistic regression showed peak flow in the leg to be independently associated with the 6-min walk distance adjusted for age, hemoglobin level, albumin, creatinine, presence of sarcopenia, and coronary artery disease (hazard ratio, 0.903; 95% confidence interval, 0.835-0.976; P = .01).

CONCLUSION

Patients with HF associated with sarcopenia have impaired endothelial function. Lower vasodilatation had a negative impact on exercise capacity, particularly prevalent in patients with sarcopenia.

Corticosteroids Mediate Heart Failure-Induced Depression through Reduced σ1-Receptor Expression

Cardiovascular diseases are risk factors for depression in humans. We recently proposed that σ1 receptor (σ1R) stimulation rescued cardiac hypertrophy and heart failure induced by transverse aortic constriction (TAC) in mice. Importantly, σ1R stimulation reportedly ameliorates depression-like behaviors in rodents. Thus, we hypothesized that impaired σ1R activity in brain triggers depression-like behaviors in animals with cardiovascular disease. Indeed, here we found that cardiac hypertrophy and heart failure induced by TAC were associated with depression-like behaviors concomitant with downregulation of σ1R expression in brain 6 weeks after surgery. σ1R levels significantly decreased in astrocytes in both the hippocampal CA1 region and dentate gyrus. Oral administration of the specific σ1R agonist SA4503 (0.3-1.0mg/kg) significantly improved TAC-induced depression-like behaviors concomitant with rescued astrocytic σ1R expression in CA1 and the dentate gyrus. Plasma corticosterone levels significantly increased 6 weeks after TAC, and chronic treatment of mice with corticosterone for 3 weeks elicited depression-like behaviors concomitant with reduced astrocytic σ1R expression in hippocampus. Furthermore, the glucocorticoid receptor antagonist mifepristone antagonized depressive-like behaviors and ameliorated decreased hippocampal σ1R expression in TAC mice. We conclude that elevated corticosterone levels trigger hippocampal σ1R downregulation and that σ1R stimulation with SA4503 is an attractive therapy to improve not only cardiac dysfunction but depression-like behaviors associated with heart failure.

Phosphodiesterase 1 regulation is a key mechanism in vascular aging

Reduced nitric oxide (NO)/cGMP signalling is observed in age-related vascular disease. We hypothesize that this disturbed signalling involves effects of genomic instability, a primary causal factor in aging, on vascular smooth muscle cells (VSMCs) and that the underlying mechanism plays a role in human age-related vascular disease. To test our hypothesis, we combined experiments in mice with genomic instability resulting from the defective nucleotide excision repair gene ERCC1 (Ercc1(d/-) mice), human VSMC cultures and population genome-wide association studies (GWAS). Aortic rings of Ercc1(d/-) mice showed 43% reduced responses to the soluble guanylate cyclase (sGC) stimulator sodium nitroprusside (SNP). Inhibition of phosphodiesterase (PDE) 1 and 5 normalized SNP-relaxing effects in Ercc1(d/-) to wild-type (WT) levels. PDE1C levels were increased in lung and aorta. cGMP hydrolysis by PDE in lungs was higher in Ercc1(d/-) mice. No differences in activity or levels of cGMP-dependent protein kinase 1 or sGC were observed in Ercc1(d/-) mice compared with WT. Senescent human VSMC showed elevated PDE1A and PDE1C and PDE5 mRNA levels (11.6-, 9- and 2.3-fold respectively), which associated with markers of cellular senescence. Conversely, PDE1 inhibition lowered expression of these markers. Human genetic studies revealed significant associations of PDE1A single nucleotide polymorphisms with diastolic blood pressure (DBP; β=0.28, P=2.47×10(-5)) and carotid intima-media thickness (cIMT; β=-0.0061, P=2.89×10(-5)). In summary, these results show that genomic instability and cellular senescence in VSMCs increase PDE1 expression. This might play a role in aging-related loss of vasodilator function, VSMC senescence, increased blood pressure and vascular hypertrophy.

Obesity and coronary microvascular disease - implications for adipose tissue-mediated remote inflammatory response

It is believed that obesity has detrimental effects on the coronary circulation. These include immediate changes in coronary arterial vasomotor responsiveness and the development of occlusive large coronary artery disease. Despite its critical role in regulating myocardial perfusion, the altered behavior of coronary resistance arteries, which gives rise to coronary microvascular disease (CMD) is poorly understood in obesity. A chronic, low-grade vascular inflammation has been long considered as one of the main underlying pathology behind CMD. The expanded adipose tissue and the infiltrating macrophages are the major sources of pro-inflammatory mediators that have been implicated in causing inadequate myocardial perfusion and, in a long term, development of heart failure in obese patients. Much less is known the mechanisms regulating the release of these cytokines into the circulation that enable them to exert their remote effects in the coronary microcirculation. This mini review aims to examine recent studies describing alterations in the vasomotor function of coronary resistance arteries and the role of adipose tissue-derived pro-inflammatory cytokines and adipokines in contributing to CMD in obesity. We provide examples of regulatory mechanisms by which adipokines are released from adipose tissue to exert their remote inflammatory effects on coronary microvessels. We identify some of the important challenges and opportunities going forward.

Noncardiac comorbidities in heart failure with reduced versus preserved ejection fraction

Heart failure patients are classified by ejection fraction (EF) into distinct groups: heart failure with preserved ejection fraction (HFpEF) or heart failure with reduced ejection fraction (HFrEF). Although patients with heart failure commonly have multiple comorbidities that complicate management and may adversely affect outcomes, their role in the HFpEF and HFrEF groups is not well-characterized. This review summarizes the role of noncardiac comorbidities in patients with HFpEF versus HFrEF, emphasizing prevalence, underlying pathophysiologic mechanisms, and outcomes. Pulmonary disease, diabetes mellitus, anemia, and obesity tend to be more prevalent in HFpEF patients, but renal disease and sleep-disordered breathing burdens are similar. These comorbidities similarly increase morbidity and mortality risk in HFpEF and HFrEF patients. Common pathophysiologic mechanisms include systemic and endomyocardial inflammation with fibrosis. We also discuss implications for clinical care and future HF clinical trial design. The basis for this review was discussions between scientists, clinical trialists, and regulatory representatives at the 10th Global CardioVascular Clinical Trialists Forum.

A simple and portable device for the quantification of TNF-α in human plasma by means of on-chip magnetic bead-based proximity ligation assay

There is a general need in healthcare systems all around the world to reduce costs in terms of time and money without compromising patients outcome. Point-of-Care Testing (POCT) is currently being used in some applications (e.g. POC coagulation devices) as an alternative to already established standard central laboratory tests to overcome sample transportation and long turnaround times. The main objective of this investigation was to quantify Tumour Necrosis Factor-alpha (TNF-α) on-chip within the clinical relevant range of 5-100 pg/mL in human pooled plasma. The novel solid-phase assay developed in this study was a magnetic bead-based proximity ligation assay (PLA) in which one of the assay proximity probes was directly immobilised onto streptavidin-coated magnetic beads. The portable device was based on a disposable and single-use cyclo-olefin polymer (COP) microfluidic chip interfaced with a quantitative real-time polymerase chain reaction (qPCR) device previously developed in-house. Sample volume was 10 µL and total assay time under 3 h. The POC device and assay developed offer portability, smaller reagent and sample consumption, and faster time-to-results compared with standard ELISAs. Determination and monitoring of TNF-α therapy at the point-of-care will help to improve clinical and/or economical outcome in governmental healthcare budgets.

Endothelial dysfunction, arterial stiffness, and heart failure

Outcomes for heart failure (HF) patients remain suboptimal. No known therapy improves mortality in acute HF and HF with preserved ejection fraction; the most recent HF trial results have been negative or neutral. Improvement in surrogate markers has not necessarily translated into better outcomes. To translate breakthroughs with potential therapies into clinical benefit, a better understanding of the pathophysiology establishing the foundation of benefit is necessary. Vascular function plays a central role in the development and progression of HF. Endothelial function and nitric oxide availability affect myocardial function, systemic and pulmonary hemodynamics, and coronary and renal circulation. Arterial stiffness modulates ventricular loading conditions and diastolic function, key components of HF with preserved ejection. Endothelial function and arterial stiffness may therefore serve as important physiological targets for new HF therapies and facilitate patient selection for improved application of existing agents.

Estimation of mean systemic filling pressure in postoperative cardiac surgery patients with three methods

PURPOSE

To assess the level of agreement between different bedside estimates of effective circulating blood volume-mean systemic filling pressure (Pmsf), arm equilibrium pressure (Parm) and model analog (Pmsa)-in ICU patients.

METHODS

Eleven mechanically ventilated postoperative cardiac surgery patients were studied. Sequential measures were made in the supine position, rotating the bed to a 30° head-up tilt and after fluid loading (500 ml colloid). During each condition four inspiratory hold maneuvers were done to determine Pmsf; arm stop-flow was created by inflating a cuff around the upper arm for 30 s to measure Parm, and Pmsa was estimated from a Guytonian model of the systemic circulation.

RESULTS

Mean Pmsf, Parm and Pmsa across all three states were 20.9 ± 5.6, 19.8 ± 5.7 and 14.9 ± 4.0 mmHg, respectively. Bland-Altman analysis for the difference between Parm and Pmsf showed a non-significant bias of -1.0 ± 3.08 mmHg (p = 0.062), a coefficient of variation (COV) of 15 %, and limits of agreement (LOA) of -7.3 and 5.2 mmHg. For the difference between Pmsf and Pmsa we found a bias of -6.0 ± 3.1 mmHg (p < 0.001), COV 17 % and LOA -12.4 and 0.3 mmHg. Changes in Pmsf and Parm and in Pmsf and Pmsa were directionally concordant in response to head-up tilt and volume loading.

CONCLUSIONS

Parm and Pmsf are interchangeable in mechanically ventilated postoperative cardiac surgery patients. Changes in effective circulatory volume are tracked well by changes in Parm and Pmsa.

Viral kinetics are associated with changes in cytokines and chemokines in serum and target organs of SSM-CVB3-infected macaques

OBJECTIVE

To determine the relationship between viral kinetics and the expression patterns for different cytokines and chemokines in the serum and organs of coxsackievirus B3 (SSM-CVB3)-infected macaques over the course of infection.

METHODS

SSM-CVB3 levels in serum and organs were measured using the Spearman-Karber 50% tissue culture infectious dose (TCID(50)) method. Cytokine and chemokine levels in the serum and organs were measured by indirect-ELISA.

RESULTS

Low viral titers were detected in the serum samples on the first day post-inoculation (p.i.) and peaked at 6 to 10 days p.i. in the serum samples from five macaques. Serum levels of IL-1β, IL-2, IL-6, IL-12p40, IL-17α, IFN-γ, TNF-α, MCP-1 and MIP-1β were detected each day and, similar to the viral titers, peaked at 6 to 10 days. IL-10 was only detected on days 10 to 14 p.i. Additionally, higher viral titers and relative viral mRNA levels were associated with higher cytokine and chemokine levels in selected tissues from infected macaques including heart, liver, spleen, lung, kidney and brain.

CONCLUSION

The results indicate that patterns of cytokine and chemokine response are associated with viral kinetics in the serum and target organs of SSM-CVB3-infected macaques, suggesting that the changes in cytokines and chemokines could help further our understanding of the progress of CVB3 infections in clinical settings.

Toll-like receptors: new players in myocardial ischemia/reperfusion injury

Innate immune and inflammatory responses have been implicated in myocardial ischemia/reperfusion (I/R) injury. However, the mechanisms by which innate immunity and inflammatory response are involved in myocardial I/R have not been elucidated completely. Recent studies highlight the role of Toll-like receptors (TLRs) in the induction of innate immune and inflammatory responses. Growing evidence has demonstrated that TLRs play a critical role in myocardial I/R injury. Specifically, deficiency of TLR4 protects the myocardium from ischemic injury, whereas modulation of TLR2 induces cardioprotection against ischemic insult. Importantly, cardioprotection induced by modulation of TLRs involves activation of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway, suggesting that there is a crosstalk between TLRs and PI3K/Akt signaling pathways. In addition, TLRs also associate with other coreceptors, such as macrophage scavenger receptors in the recognition of their ligands. TLRs are also involved in the induction of angiogenesis, modulation of stem cell function, and expression of microRNA, which are currently important topic areas in myocardial I/R. Understanding how TLRs contribute to myocardial I/R injury could provide basic scientific knowledge for the development of new therapeutic approaches for the treatment and management of patients with heart attack.

Constitutive induction of pro-inflammatory and chemotactic cytokines in cystathionine beta-synthase deficient homocystinuria

Cystathionine beta-synthase (CBS) deficient homocystinuria (HCU) is an inherited metabolic defect that if untreated, typically results in cognitive impairment, connective tissue disturbances, atherosclerosis and thromboembolic disease. In recent years, chronic inappropriate expression of the inflammatory response has emerged as a major driving force of both thrombosis and atherosclerotic lesion development. We report here a characterization of the abnormalities in cytokine expression induced in both a mouse model of HCU and human subjects with the disease in the presence and absence of homocysteine lowering therapy. HCU mice exhibited highly significant induction of the pro-inflammatory cytokines Il-1alpha, Il-1beta and TNF-alpha. Similarly, in untreated/poorly compliant human subjects with HCU we observed constitutive induction of multiple pro-inflammatory cytokines (IL-1alpha, IL-6, TNF-alpha, Il-17 and IL-12(p70)) and chemotactic chemokines (fractalkine, MIP-1alpha and MIP-1beta) compared to normal controls. These HCU patients also exhibited significant induction of IL-9, TGF-alpha and G-CSF. The expression levels of anti-inflammatory cytokines were unaffected in both HCU mice and human subjects with the disease. In the human subjects, homocysteine lowering therapy was associated with either normalization or significant reduction of all of the pro-inflammatory cytokines and chemokines investigated. We conclude that HCU is a disease of chronic inflammation and that aberrant cytokine expression has the potential to contribute to multiple aspects of pathogenesis. Our findings indicate that anti-inflammatory strategies could serve as a useful adjuvant therapy for this disease.

Circulating cytokine concentrations in dogs with different degrees of myxomatous mitral valve disease

Cytokines have been associated with the progression of congestive heart failure (CHF) in humans and may be implicated in the pathophysiology of myxomatous mitral valve disease (MMVD) in dogs. The aim of this study was to determine the serum concentrations of cytokines in dogs with MMVD. The study included 16 Cairn terriers with no or minimal mitral regurgitation (MR), 41 Cavalier King Charles Spaniels (CKCS) with different degrees of MR and 11 dogs of different breeds with CHF due to MMVD. Granulocyte-macrophage colony-stimulating factor, interferon-γ, interleukin (IL)-2, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, keratinocyte-derived chemokine, interferon-γ-induced protein and monocyte chemoattractant protein-1 (MCP-1) were measured using a canine-specific multiplex immunoassay. CHF dogs had significantly higher MCP-1 concentrations than dogs with no or minimal MR. Among the CKCS, IL-2 and IL-7 decreased with increasing left atrial size and IL-7 also decreased with increasing MR. IL-8 decreased with increasing left ventricular end-systolic internal dimensions. MCP-1 was increased in CHF dogs compared to healthy control dogs and IL-2, IL-7 and IL-8 decreased with increasing indices of disease severity. The results suggest a role for these cytokines in canine MMVD and CHF.

Treatment of anemia in heart failure: potential risks and benefits of intravenous iron therapy in cardiovascular disease

Iron-deficiency anemia is common in patients with heart failure (HF), but the optimum diagnostic tests to detect iron deficiency and the treatment options to replete iron have not been fully characterized. Recent studies in patients with HF indicate that intravenous iron can rapidly replenish iron stores in patients having iron-deficiency anemia, with resultant increased hemoglobin levels and improved functional capacity. Preliminary data from a subgroup analysis also suggest that supplemental intravenous iron therapy can improve functional capacity even in those subjects without anemia. The mechanisms responsible for this observation are not fully characterized, but may be related to beneficial effects of iron supplementation on mitochondrial respiration in skeletal muscle. The long-term safety of using intravenous iron supplementation in HF populations is not known. Iron is a known pro-oxidant factor that can inhibit nitric oxide signaling and irreversibly injury cells. Increased iron stores are associated with vascular endothelial dysfunction and increased risk of coronary heart disease events. Additional clinical trials are needed to more fully characterize the therapeutic potential and safety of intravenous iron in HF patients.

Immune modulation in heart failure: past challenges and future hopes

Immune-modulation therapy has had great success in various inflammatory diseases. Despite the promising results of preliminary studies in anti-tumor necrosis factor-α therapies, large randomized studies have lacked positive clinical outcomes in patients with heart failure. These results have led to the idea that therapies directed toward specific inflammatory mediators may not be the answer and lead us toward the development of novel anti-inflammatory strategies that may involve a broader spectrum of inflammatory mediators. Therapeutic plasma exchange has been demonstrated as a safe treatment, and preliminary outcomes led us to develop new treatment schemes.

Exercise training leads to a reduction of elevated myostatin levels in patients with chronic heart failure

BACKGROUND

In chronic heart failure (CHF), cardiac cachexia is often associated with the terminal stage of this disease. In animal studies it has been demonstrated that myostatin, a key regulator of skeletal muscle mass, is elevated in advanced stages of this syndrome.

DESIGN

The aim of the present study was to investigate the expression of myostatin in patients with late stage CHF (NYHA IIIb) in comparison to healthy subjects. Furthermore the effects of physical exercise on myostatin were analyzed.

METHODS

Twenty-four patients were either randomized to a sedentary control group (CHF-S) or exercise training (CHF-E). At baseline and after 12 weeks mRNA and myostatin protein in the peripheral skeletal muscle as well as myostatin serum concentration were measured. Furthermore 12 age-matched healthy men were compared to all patients at baseline (HC).

RESULTS

CHF patients showed a two-fold increase of myostatin mRNA (p = 0.05) and a 1.7-fold (p = 0.01) augmentation of protein content in skeletal muscle compared to healthy subjects. In late-stage CHF, exercise training led to a 36% reduction of the mRNA and a 23% decrease of the myostatin protein compared to baseline. The serum concentration of myostatin revealed no significant alteration between the groups.

CONCLUSION

In the skeletal muscle, myostatin increases significantly in the course of CHF. The observed effects of a significant reduction of myostatin in skeletal muscle after 12 weeks of exercise training demonstrate the reversibility of molecular changes that might be able to halt the devastating process of muscle wasting in chronic heart failure.

Pharmacological treatment of chronic systolic heart failure: are we scraping the bottom of the barrel?

Heart failure is a major health problem and its prevalence is growing, primarily as a consequence of the aging of the population. Recently, we have witnessed significant progress in reducing the mortality associated with chronic heart failure due to the introduction of renin-angiotensin-aldosterone system inhibitors, beta-blocking agents and the use of electrical devices. However, the prognosis of heart failure is still so disappointing that it remains the leading cause of death in developed countries. This grim record impels the search for new therapeutic strategies. The objective of this paper is to briefly review the results of some recent trials that have been put in place to test the effects of drugs that are deemed to be potentially capable of improving the prognosis of chronic systolic heart failure patients. Despite compelling theoretical premises, the results to date appear to be weak or even disappointing.

What causes a broken heart--molecular insights into heart failure

Our understanding of the molecular processes which regulate cardiac function has grown immeasurably in recent years. Even with the advent of β-blockers, angiotensin inhibitors and calcium modulating agents, heart failure (HF) still remains a seriously debilitating and life-threatening condition. Here, we review the molecular changes which occur in the heart in response to increased load and the pathways which control cardiac hypertrophy, calcium homeostasis, and immune activation during HF. These can occur as a result of genetic mutation in the case of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) or as a result of ischemic or hypertensive heart disease. In the majority of cases, calcineurin and CaMK respond to dysregulated calcium signaling and adrenergic drive is increased, each of which has a role to play in controlling blood pressure, heart rate, and left ventricular function. Many major pathways for pathological remodeling converge on a set of transcriptional regulators such as myocyte enhancer factor 2 (MEF2), nuclear factors of activated T cells (NFAT), and GATA4 and these are opposed by the action of the natriuretic peptides ANP and BNP. Epigenetic modification has emerged in recent years as a major influence cardiac physiology and histone acetyl transferases (HATs) and histone deacetylases (HDACs) are now known to both induce and antagonize hypertrophic growth. The newly emerging roles of microRNAs in regulating left ventricular dysfunction and fibrosis also has great potential for novel therapeutic intervention. Finally, we discuss the role of the immune system in mediating left ventricular dysfunction and fibrosis and ways this can be targeted in the setting of viral myocarditis.

Cardioprotection by a nonerythropoietic, tissue-protective peptide mimicking the 3D structure of erythropoietin

Erythropoietin (EPO), originally identified for its critical hormonal role in regulating production and survival of erythrocytes, is a member of the type 1 cytokine superfamily. Recent studies have shown that EPO has cytoprotective effects in a wide variety of tissues, including the heart, by preventing apoptosis. However, EPO also has undesirable effects, such as thrombogenesis. In the present study, we investigated whether a helix B-surface peptide (HBSP), a nonerythropoietic, tissue-protective peptide mimicking the 3D structure of erythropoietin, protects cardiomyocytes from apoptosis in vitro and in vivo. In cultured neonatal rat cardiomyocytes, HBSP clearly inhibited apoptosis (approximately 80%) induced by TNF-alpha, which was comparable with the effect of EPO, and activated critical signaling pathways of cell survival, including Akt, ERK1/2, and STAT3. Among these pathways, Akt was shown to play an essential role in HBSP-induced prevention of apoptosis, as assessed by using a small interfering RNA approach. In the dilated cardiomyopathic hamster (J2N-k), whose cardiac tissues diffusely expressed TNF-alpha, HBSP also inhibited apoptosis (approximately 70%) and activated Akt in cardiomyocytes. Furthermore, the levels of serum creatine kinase activity and of cardiac expression of atrial natriuretic peptide, a marker of chronic heart failure, were down-regulated in animals treated with HBSP. These data demonstrate that HBSP protects cardiomyocytes from apoptosis and leads to a favorable outcome in failing hearts through an Akt-dependent pathway. Because HBSP does not have the undesirable effects of EPO, it could be a promising alternative for EPO to treat cardiovascular diseases, such as myocardial infarction and heart failure.

The role of exercise on L-arginine nitric oxide pathway in chronic heart failure

Chronic heart failure (CHF) is a pathological state with high morbidity and mortality and the full understanding of its genesis remain to be elucidated. In this syndrome, a cascade of neurohormonal and hemodynamic mechanisms, as well as inflammatory mediators, are activated to improve the impaired cardiac function. Clinical and experimental observations have shown that CHF is associated with a generalized disturbance in endothelium-dependent vasodilation, which may contribute to the progression of ventricular and vascular remodelling in this syndrome. There is also accumulating evidence that disturbances in nitric oxide (NO) availability is involved in the development of heart failure at the systemic and cardiac levels. NO is a ubiquitous signalling molecule which causes potent vasodilation, inhibits platelet activation and regulates the contractile properties of cardiac myocytes. It is generated from the amino acid L-arginine via constitutive and inducible isoforms of the enzyme NO synthase (NOS). There is evidence that exercise, a nonpharmacological tool, improves symptoms, fitness (VO_2peak), quality of life and NO bioavailability in CHF population. This review examines different aspects of the L-arginine-NO pathway and inflammation in the physiopathology of CHF and highlights the important beneficial effects of exercise in this disease.

Brachial artery differential characteristic impedance: Contributions from changes in young's modulus and diameter

This examination of brachial artery (BA) differential characteristic impedance, DeltaZ (c), illustrates that changes in Z (c) can occur from changes in either BA wall stiffness (Young's modulus, E) and/or its diameter, D. Furthermore, we assessed how changes in both E and D combine in either an isolated, synergistic, or antagonistic manner to yield the net change in BA Z (c). The basis of this analysis is a partial differential equation which approximates DeltaZ (c) as a total differential. The effects on BA DeltaZ (c) of acetylcholine, atenolol, fenoldapine, nitroglycerin, hydrochlorothiazide and other medications are examined using data from previously published studies. Clinical situations which alter BA Z (c), such as congestive heart failure, hypertension, and hyperemia, are also analyzed. Results illustrate the usefulness of the present approach in differentiating how medications, hyperemia, and pathological conditions affect BA DeltaZ (c) by causing independent changes to E and/or D.

Impact of exercise training on myostatin expression in the myocardium and skeletal muscle in a chronic heart failure model

AIMS

In late-stage chronic heart failure (CHF), elevated cytokines and cachexia are often observed. Several studies have shown that exercise training exerts beneficial effects on skeletal muscle in this setting. Furthermore, it has been shown that the expression of myostatin, a key regulator of skeletal muscle mass, is increased in a variety of cachectic states. This study aimed to investigate the expression of myostatin in CHF, the influence of exercise training on myostatin levels, and regulation of myostatin by tumour necrosis factor-alpha (TNF-alpha).

METHODS AND RESULTS

In an animal model of CHF (LAD-ligation model), protein expression of myostatin was elevated 2.4-fold in the skeletal muscle and more than four-times in the myocardium, compared with control (Co). Exercise training on a treadmill over 4 weeks led to a significant reduction in myostatin protein expression in the skeletal muscle and the myocardium of CHF animals, with values returning to baseline levels. In differentiated C2C12 cells, TNF-alpha induced the expression of myostatin through a p38MAPK-dependent pathway involving nuclear factor kappa-B (NF-kappaB). The increased TNF-alpha mRNA levels in the skeletal muscle of CHF animals correlated significantly with myostatin expression.

CONCLUSION

These alterations in myostatin expression in the skeletal and heart muscle following exercise training could help to explain the beneficial anti-catabolic effects of exercise training in CHF.

Endothelial dysfunction: from molecular mechanisms to measurement, clinical implications, and therapeutic opportunities

Endothelial dysfunction has been implicated as a key factor in the development of a wide range of cardiovascular diseases, but its definition and mechanisms vary greatly between different disease processes. This review combines evidence from cell-culture experiments, in vitro and in vivo animal models, and clinical studies to identify the variety of mechanisms involved in endothelial dysfunction in its broadest sense. Several prominent disease states, including hypertension, heart failure, and atherosclerosis, are used to illustrate the different manifestations of endothelial dysfunction and to establish its clinical implications in the context of the range of mechanisms involved in its development. The size of the literature relating to this subject precludes a comprehensive survey; this review aims to cover the key elements of endothelial dysfunction in cardiovascular disease and to highlight the importance of the process across many different conditions.

Tumor necrosis factor-alpha antagonist use and heart failure in elderly patients with rheumatoid arthritis

BACKGROUND

Clinical trials have shown that tumor necrosis factor-alpha antagonists (TNFAs) confer little benefit, and some may cause potential harm in advanced heart failure (HF). Although TNFAs had significant benefits in treating rheumatoid arthritis (RA), little is known whether the drugs pose an increased risk of HF in older patients with RA.

METHODS

A cohort study was conducted using data from Medicare and drug benefit programs in 2 states (1994-2004). We identified patients with RA aged > or =65 who received TNFA or methotrexate (MTX). The cohort was divided into patients with and without previous HF. We considered demographic variables, cardiovascular risk factors, RA severity-related measures, and other comorbidities. The primary end point was hospitalization with HF. We used stratified Cox proportional hazards regression to estimate the adjusted effect of TNFAs on HF hospitalization.

RESULTS

The cohort consisted of 1,002 TNFA users and 5,593 MTX users. There were 59 HF admissions during 1,680 person-years of TNFA use and 227 HF admissions during 10,623 person-years of MTX use. Comparing TNFA with MTX users, the adjusted hazard ratio for HF hospitalization was 1.70 (95% confidence interval 1.07-2.69). We found similar results in patients with and without previous HF. Among patients with previous HF, the adjusted hazard ratio for death was 4.19 (95% confidence interval 1.48-11.89).

CONCLUSIONS

TNFAs may increase the risk of both first hospitalization and exacerbation of HF in elderly patients with RA. The potential for residual confounding in our study cannot be ruled out; larger and more detailed studies are needed to confirm the findings.

Autoimmunological features in inflammatory cardiomyopathy

During recent years, increasing evidence has been obtained that cellular as well as humoral autoimmunity is involved in the pathogenesis of dilated cardiomyopathy (DCM). The immune system is generally activated by viral infections with the objective of virus elimination from the myocardium. However, a relevant number of patients demonstrate viral persistence and/or chronic inflammation in the myocardium. This chronic myocardial inflammation, defined by chronic inflammation, is termed "inflammatory cardiomyopathy" according to the WHO classification of cardiomyopathies. Chronic inflammation is frequently followed by the development of autoimmunity. A breakdown in the control mechanisms protecting against autoimmune reactions by both presentation of normally not accessible self-antigens and bystander- activation, induced by the pathogen, leads to the formation of autoreactive antibodies and T cells. The auto-reactive antibodies interact directly with heart tissue resulting in altered signal transduction or complement activation, whereas the T cell-mediated mechanisms include direct attack by cytotoxic T cells or indirect effects of cytotoxic cytokines released by stimulated T cells or macrophages.

Anti-tumour necrosis factor-alpha therapy in heart failure: future directions

The elevated level of tumour necrosis factor-alpha (TNF-alpha) in patients with heart failure has triggered interest in investigating the role of TNF-alpha in the pathogenesis of heart failure. Both clinical and experimental evidence has suggested that high levels of TNF-alpha occur in heart failure and lead to progression of left ventricular dysfunction. In addition, it has been documented that inhibition of TNF-alpha reverses its deleterious effects in heart failure. A number of clinical trials have been initiated to investigate the effect of anti-TNF-alpha therapy in patients with heart failure. The discouraging results of recent clinical trials of anti-TNF-alpha therapy in patients with heart failure have raised a number of questions about the role of TNF-alpha in heart failure. The present review critically analyzes the reasons of failure of anti-TNF-alpha therapy in heart failure. Moreover the potential approaches for the development of new anti-TNF-alpha therapy has been discussed which may open new vista of the management of heart failure.

Glucan phosphate attenuates cardiac dysfunction and inhibits cardiac MIF expression and apoptosis in septic mice

Myocardial dysfunction is a major consequence of septic shock and contributes to the high mortality of sepsis. We have previously reported that glucan phosphate (GP) significantly increased survival in a murine model of cecal ligation and puncture (CLP)-induced sepsis. In the present study, we examined the effect of GP on cardiac dysfunction in CLP-induced septic mice. GP was administered to ICR/HSD mice 1 h before induction of CLP. Sham surgically operated mice served as control. Cardiac function was significantly decreased 6 h after CLP-induced sepsis compared with sham control. In contrast, GP administration prevented CLP-induced cardiac dysfunction. Macrophage migration inhibitory factor (MIF) has been implicated as a major factor in cardiomyocyte apoptosis and cardiac dysfunction during septic shock. CLP increased myocardial MIF expression by 88.3% ( P < 0.05) and cardiomyocyte apoptosis by 7.8-fold ( P < 0.05) compared with sham control. GP administration, however, prevented CLP-increased MIF expression and decreased cardiomyocyte apoptosis by 51.2% ( P < 0.05) compared with untreated CLP mice. GP also prevented sepsis-caused decreases in phospho-Akt, phospho-GSK-3β, and Bcl-2 levels in the myocardium of septic mice. These data suggest that GP treatment attenuates cardiovascular dysfunction in fulminating sepsis. GP administration also activates the phosphoinositide 3-kinase/Akt pathway, decreases myocardial MIF expression, and reduces cardiomyocyte apoptosis.

Nutritional Recommendations for Patients With Heart Failure

Promoting optimal nutritional intake may play an important role in the management of patients with heart failure. Unfortunately, no nutritional guidelines are currently available to assist clinicians in assuring adequate nutritional intake of these patients. The purposes of this article are to review currently available information on nutrition in heart failure and outline initial recommendations for micronutrient, protein, and omega-3 fatty intake. In addition, implications regarding the recent data showing improved health outcomes in obese patients are also addressed.

Immune activation is associated with reduced skeletal muscle mass and physical function in chronic heart failure

BACKGROUND

Chronic heart failure is characterized by immune activation and increased circulating levels of cytokines. Whether humoral factors contribute to the peripheral manifestations of the heart failure syndrome, such as muscle atrophy and reduced physical work capacity, however, is not clear.

METHODS

We measured circulating cytokines (tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6)), their soluble receptors (sTNF-alpha RII, IL-6sR), markers of immune activation (C-reactive protein (CRP)), muscle mass, aerobic capacity and muscle strength in 10 patients with heart failure (mean +/- S.E.; 63 +/- 3 years) and 11 controls (70 +/- 3 years).

RESULTS

Heart failure patients exhibited decreased aerobic capacity (P < 0.01) and leg muscle strength (P < 0.05). Reduced muscle strength persisted in heart failure patients after statistical adjustment for differences in skeletal muscle size. All inflammatory markers were increased in heart failure patients (P < or = 0.05 to P < 0.01) compared to controls, with the exception of TNF-alpha. Despite no group differences in TNF-alpha, higher concentrations of this cytokine were correlated to lower skeletal muscle mass in the combined study population (range of r-values: -0.436 to -0.545; P < 0.05 to P < 0.02), as were IL-6 levels (range of r-values: -0.438 to -0.443; P < 0.05). TNF-alpha, sTNF-alpha RII, IL-6 and CRP showed strong negative relationships to aerobic capacity (range of r-values: -0.579 to -0.751; P < 0.01 to P < 0.001). In addition, elevated levels of IL-6 and TNF-alpha were associated with reduced leg and forearm skeletal muscle strength (range of r-values: -0.440 to -0.674; P < 0.05 to P < 0.01). Finally, correlations between cytokines and functional measures were present when heart failure patients were analyzed separately (range of r-values: -0.646 to -0.673; P < 0.05).

CONCLUSIONS

Our results suggest that circulating cytokines are related to both skeletal muscle mass and physical function. These findings provide further evidence to support the hypothesis that immune activation contributes to skeletal muscle atrophy and reduced functional capacity in heart failure patients.

Serial measurements of peripheral vascular reactivity and exercise capacity in congestive heart failure and after heart transplantation

BACKGROUND

The regulation of nutritive blood flow to skeletal muscles during exercise seems to make an important contribution to exercise capacity. In congestive heart failure (CHF) this regulation seems to be impaired, with attenuated peripheral vasodilatory capacity. The results regarding improvement of peripheral vasoreactivity after heart transplantation (HTx) are conflicting, and the contribution of impaired peripheral vasoreactivity to the observed reduced exercise capacity among heart transplant recipients (HTR) has not been well elucidated. We therefore assessed the reversibility of impaired vasoreactivity in forearm and calf after HTx with relationship to exercise capacity.

METHODS AND RESULTS

The vasoreactivity of both forearm and calf was studied with venous occlusion plethysmography and related to exercise capacity in 64 patients with CHF and in 22 controls. Of these patients, 29 patients underwent HTx, and the same measurements were performed 10 days, 6 months and 1 year after HTx, and in a group of 15 HTR who had undergone HTx several years ago. Our main findings were (1) impaired resting blood flow in patients with CHF improved after HTx and even surpassed levels of controls; (2) peak forearm blood flow remained attenuated early after HTx, but normalized during the first year postoperatively; (3) both forearm and calf minimal resistance remained elevated after HTx; (4) vascular reactivity displays regional variations in forearm and calf both during CHF and after HTx; and (5) peripheral vascular reactivity relate to exercise performance in both patients with CHF and HTR, but the relationship seemed more pronounced in CHF.

CONCLUSION

With impaired vasoreactivity related to limited exercise capacity in CHF, improvement is evident after HTx, but both forearm and calf minimal resistance remains elevated. These findings suggest increased vasoconstrictor drive to both exercising and non-exercising muscles, possibly contributing to persistent physical limitation after HTx.

Electrical remodeling of cardiac myocytes from mice with heart failure due to the overexpression of tumor necrosis factor-alpha

Mice that overexpress the inflammatory cytokine tumor necrosis factor-alpha in the heart (TNF mice) develop heart failure characterized by atrial and ventricular dilatation, decreased ejection fraction, atrial and ventricular arrhythmias, and increased mortality (males > females). Abnormalities in Ca2+ handling, prolonged action potential duration (APD), calcium alternans, and reentrant atrial and ventricular arrhythmias were previously observed with the use of optical mapping of perfused hearts from TNF mice. We therefore tested whether altered voltage-gated outward K+ and/or inward Ca2+ currents contribute to the altered action potential characteristics and the increased vulnerability to arrhythmias. Whole cell voltage-clamp recordings of K+ currents from left ventricular myocytes of TNF mice revealed an approximately 50% decrease in the rapidly activating, rapidly inactivating transient outward K+ current Ito and in the rapidly activating, slowly inactivating delayed rectifier current IK,slow1, an approximately 25% decrease in the rapidly activating, slowly inactivating delayed rectifier current IK,slow2, and no significant change in the steady-state current Iss compared with controls. Peak amplitudes and inactivation kinetics of the L-type Ca2+ current ICa,L were not altered. Western blot analyses revealed a reduction in the proteins underlying Kv4.2, Kv4.3, and Kv1.5. Thus decreased K+ channel expression is largely responsible for the prolonged APD in the TNF mice and may, along with abnormalities in Ca2+ handling, contribute to arrhythmias.

Dietary Fat Intake and Proinflammatory Cytokine Levels in Patients With Heart Failure

BACKGROUND

Dietary fat intake affects proinflammatory cytokine levels of healthy adults. Whether dietary fats have similar effects in patients with heart failure (HF) is unknown. The purposes of this study were to determine (1) effect of dietary fat on interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, and soluble receptors sTNF-R1 and sTNF-R2 levels in patients with HF and (2) subsequent impact of these levels on event-free survival.

METHODS AND RESULTS

Forty-two patients provided 4-day food diaries and blood for cytokines. Event-free survival curves were calculated by Kaplan-Meier method and groups compared using log-rank test. IL-6 was not related to fat intake. TNF-alpha levels were elevated in patients with diets higher versus lower in saturated (6.9 +/- 5 versus 4.2 +/- 2 pg/mL) and trans fats (6.8 +/- 4.5 versus 4.5 +/- 2.8 pg/mL). Patients consuming diets higher in polyunsaturated fats had lower sTNF-R1 (2391 +/- 1010 versus 3373 +/- 2098 pg/mL) and sTNF-R2 (3803 +/- 1187 versus 5974 +/- 3275 pg/mL) levels. Higher omega-3 intake produced similar results: sTNF-R1 (2323 +/- 1304 versus 3307 +/- 1973) and sTNF-R2 (4117 +/- 2646 versus 5409 +/- 2801). Event-free survival was decreased in patients with higher TNF-alpha and sTNF-R1 levels.

CONCLUSION

Dietary fat intake may affect proinflammatory cytokine levels in patients with HF. Research to determine whether changing composition of dietary fat can alter proinflammatory cytokine activity of HF patients is warranted.

Impaired Vasoreactivity in End-Stage Heart Failure Patients on Intravenous Inotropic Support

BACKGROUND

Vasoreactivity is known to be impaired in heart failure patients; however, it has not been determined whether standard medical therapy for end-stage heart failure patients (ES-HF) ameliorates this impairment. Therefore, we sought to investigate flow-mediated dilation (FMD) responses in ES-HF with normal or near normal cardiac indices from continuous inotropic support.

METHODS AND RESULTS

Vascular ultrasound was used to assess FMD responses to isometric exercise and cuff occlusion in 15 ES-HF patients and 5 control subjects (C). ES-HF patients had significant hyperemic response to maximal exercise (P < .05), which was blunted relative to C (ES-HF; 84 +/- 21 mL/min versus C; 299 +/- 85 mL/min, P < .05). ES-HF patients did not show a significant hyperemic response to submaximal exercise. C had a significant increase in arterial diameter that exceeded ES-HF after both maximal (C; 8 +/- 1% versus. ES-HF; -0.9 +/- 0.86%, P < .05) and submaximal exercise (C; 6 +/- 1% versus ES-HF; 0.57 +/- 1%, P < .05). FMD responses at similar absolute workloads showed that both the mean hyperemic response and the change in arterial diameter were significantly greater in C. After cuff occlusion, the mean hyperemic response for ES-HF was again significantly blunted compared with C (ES-HF; 117 +/- 26% versus C; 352 +/- 86%, P < .05). After cuff occlusion, arterial diameter in C significantly increased in response to hyperemia, whereas ES-HF patients had a paradoxical vasoconstrictive response (C; 10.7 +/- 1.1% versus ES-HF; -5.3 +/- 1.5%, P < .05).

CONCLUSION

Peripheral vasoreactivity in response to either maximal exercise, submaximal exercise, or hyperemic stimuli is impaired in ES-HF patients with normal resting cardiac outputs.