Increased nitric oxide in proportion to the severity of heart failure in patients with dilated cardiomyopathy: close correlation of tumor necrosis factor-alpha with systemic and local production of nitric oxide

Time-dependent influence of infliximab on hemodynamic responses and cardiac injuries of isoproterenol-induced myocardial infarction in rats

Immune-induced inflammation plays an important role both in aggravating and healing of post myocardial infarction (MI) injuries. Potent anti-inflammatory and local immunomodulatory activity of infliximab has been suggested to have modulating effects on immune responses after MI. The aim of the present study was to evaluate the efficacy of infliximab on hemodynamic responses and myocardial injuries following isoproterenol-induced myocardial infarction. Male Wistar rats, weighting 260 ± 20 g were assigned into ten groups (n = 6) of saline (normal saline), infliximab (7 mg/kg), isoproterenol (100 mg/kg for two consecutive days), and isoproterenol plus infliximab (30 min after the second injection of isoproterenol). The heart tissues and serums were analyzed 24, 48, 72, and 96 h post-MI and hemodynamic parameters, histopathological changes, malondialdehyde (MDA), Total antioxidant capacity (TAC), lactate dehydrogenase (LDH), and lactate levels were assessed in the respective groups. Infliximab partially improved hemodynamic depression in the first days after MI, but the heart became more suppressed later. A similar result also obtained at the MDA tissue levels but not serum levels. Anti-inflammatory effects of Infliximab may improve cardiac function and prevent heart tissue injury early after MI; however, it can worsen the condition later by inhibiting compensatory reactions such as cardiac remodeling and tissue repair.

The NO/ONOO-cycle as the central cause of heart failure

The NO/ONOO-cycle is a primarily local, biochemical vicious cycle mechanism, centered on elevated peroxynitrite and oxidative stress, but also involving 10 additional elements: NF-κB, inflammatory cytokines, iNOS, nitric oxide (NO), superoxide, mitochondrial dysfunction (lowered energy charge, ATP), NMDA activity, intracellular Ca(2+), TRP receptors and tetrahydrobiopterin depletion. All 12 of these elements have causal roles in heart failure (HF) and each is linked through a total of 87 studies to specific correlates of HF. Two apparent causal factors of HF, RhoA and endothelin-1, each act as tissue-limited cycle elements. Nineteen stressors that initiate cases of HF, each act to raise multiple cycle elements, potentially initiating the cycle in this way. Different types of HF, left vs. right ventricular HF, with or without arrhythmia, etc., may differ from one another in the regions of the myocardium most impacted by the cycle. None of the elements of the cycle or the mechanisms linking them are original, but they collectively produce the robust nature of the NO/ONOO-cycle which creates a major challenge for treatment of HF or other proposed NO/ONOO-cycle diseases. Elevated peroxynitrite/NO ratio and consequent oxidative stress are essential to both HF and the NO/ONOO-cycle.

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.

Do Archaea and bacteria co-infection have a role in the pathogenesis of chronic chagasic cardiopathy?

Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms.

MATERIALS AND METHODS

eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies.

RESULTS

MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.

Cytokines and myocardial dysfunction: state of the art

BACKGROUND

Myocardial dysfunction has been associated with inflammation and cytokine modulation.

OBJECTIVES

The study objective was to understand the role of cytokines in the pathophysiology and management of myocardial dysfunction.

METHODS

Heart failure has been revisited with revision of the pertinent published articles in the Medline, Scopus, Cochrane Database of Systematic Reviews, and EBSCO Host research.

RESULTS

For the proinflammatory cytokines, illumination of this important point requires further diagnostic and therapeutic investigations. Data on chronic heart failure are not so reassuring; therefore, patients with advanced heart failure should not be treated with anticytokines at this time.

CONCLUSION

Further studies are warranted to pave the way for introducing cytokine and immunomodulation therapy at the optimal and appropriate time.

Inhibition of endogenous nitric oxide synthase augments contractile response to adenylyl cyclase stimulation without altering mechanical efficiency in patients with idiopathic dilated cardiomyopathy

BACKGROUND

Increased nitric oxide (NO) in the failing heart attenuates the myocardial contractile response to beta-adrenergic receptor stimulation. However, the physiological effects of NO on the beta-adrenergic post-receptor signaling system are unknown. The objective of the present study was to examine the effects of cardiac NO synthase (NOS) inhibition on left ventricular (LV) hemodynamics and mechanoenergetics in response to adenylyl cyclase stimulation in human heart failure.

METHODS AND RESULTS

The study group comprised 13 patients with heart failure because of idiopathic cardiomyopathy (IDC). Emax was examined as an index of LV contractility, LV external work (EW), pressure-volume area (PVA), myocardial oxygen consumption (MVO2), and mechanical efficiency (EW/MVO2) with the use of conductance and coronary sinus thermodilution catheters before and during colforsin daropate infusion, and during concurrent infusion of colforsin daropate with the NOS inhibitor, NG-monomethyl-L-arginine (L-NMMA; 200 micromol). Colforsin daropate increased Emax by 53% and EW by 18%, and reduced PVA by 14%, without altering MVO2 or mechanical efficiency. The combination of colforsin daropate with L-NMMA further increased Emax by 26% and reduced PVA by 9%, without altering MVO2 or mechanical efficiency.

CONCLUSIONS

These findings suggest endogenous NO may modulate beta-adrenergic post-receptor pathways and preserve myocardial efficiency in patients with IDC.

Does nitric oxide contribute to progressive cardiac tissue damage and dysfunction after infarction?

Myocardial infarction induces contractile dysfunction and remodeling that can lead to heart failure. Nitric oxide has been proposed as one of the major actors of this pathophysiologic process. We note that N (G)-nitro-L-arginine methyl ester (L-NAME) administration from day 2 to day 7 after myocardial infarction in rats improves stroke volume, preserves cardiac compliance, and reduces infarct expansion. Our observations lead to the hypothesis that the mechanisms by which cytokines contribute to myocardial remodeling and dysfunction in the days after infarction might involve *NO signalling pathways.

Expression of interferon-gamma and interleukin-4 production in CD4+ T cells in patients with chronic heart failure

The prevalence of inflammation is high among patients with chronic heart failure (CHF). Reduced ejection fraction was associated with frequency of CD4(+) T cells of leukocytes. Therefore, we investigated inflammatory cytokines of expression markers in CD4(+) T cells in patients with CHF. Blood samples were obtained from 103 patients with CHF, from 83 patients with stable angina (SA), and from 57 controls. Interferon-gamma (IFN-gamma)-positive CD4(+) T cells and interleukin-4 (IL-4)-positive CD4(+) T cells were analyzed using 3-color flow cytometry. The frequency (%) of IFN-gamma-positive CD4(+) T cells increased in patients with CHF compared with those with SA and controls (CHF: 28.3 +/- 13.8, SA: 23.50 +/- 10.38, controls: 19.00 +/- 7.45, P < 0.001). There was no significant difference in the frequency of IL-4-positive CD4(+) T cells among the three groups. The frequencies of CD4(+) T cells that stained for IFN-gamma decreased from 32.37% +/- 16.40% on admission to 26.91% +/- 12.53% after 2 weeks in 26 patients with CHF. B-type natriuretic peptide (pg/ml) and high-sensitivity C-reactive protein (mg/dl) levels decreased from 251.7 +/- 150.4 and 0.64 +/- 0.78 on admission to 208.2 +/- 166.4 and 0.36 +/- 0.34 after 2 weeks in the 26 patients with CHF. We have demonstrated expression of IFN-gamma production of CD4(+) T cells during CHF. Prevention of unwanted T cell activation could represent a new target in the treatment of CHF.

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.

The incidence of new onset congestive heart failure and heart failure exacerbation in Veteran’s Affairs patients receiving tumor necrosis factor alpha antagonists

The objective of this study was to evaluate the incidence of new onset or worsening congestive heart failure in Veteran's Affairs (VA) patients who have received infliximab, etanercept, or adalimumab, and to compare mortality rates in these patients to control populations. We enrolled three groups of patients for this retrospective study: TNF-alpha group (n = 103), a rheumatoid arthritis (RA) control group (n = 100), and a control group without RA (n = 100). All patients at our VA facility who had received at least one dose of the TNF-alpha antagonists were included in the TNF-alpha group. Admissions for CHF did not differ between the three groups: TNF-alpha 7 (6.7%), RA control 8 (8%), non-RA control 7 (7%); P = 0.940. Mortality rates were not significantly different: TNF-alpha 4 (3.8%), RA control 7 (7%), non-RA control 11 (11%); P = 0.147. Our study showed no difference between the three groups in either CHF exacerbation or mortality.

Nitric oxide (NO) is a new clinical biomarker of survival in the elderly patients and its efficacy might be nearly equal to albumin

BACKGROUND

For elderly patients, the consideration of prognostic factors is very important, but there have been few reports about the potential use of vasoactive substances as prognostic markers in the elderly.

OBJECTIVE

We assessed endocrinological substances, such as plasma NO(x) (metabolites of NO), as the prognostic marker in elderly. We compared their efficacy with that of such well-known markers as albumin and pro-inflammatory cytokines such as IL-6.

METHODS

The patients were recruited consequently from the clinics of Nagoya University Hospital or related home care services facilities. One hundred and twenty seven elderly aged 65 and older were registered. Biochemical analyses such as albumin, total cholesterol, BNP, and NO(x) were measured upon enrollment. The main outcome was the survival rate.

RESULTS

Forty-six patients died during the follow-up period. Mann-Whitney's U-test showed that the levels of age, hemoglobin, total protein, serum albumin, serum creatinine, total cholesterol, HDL-cholesterol, LDL-cholesterol, high sensitive CRP, NO(x), IL-6, and TNF-alpha were significantly different between the living and deceased subjects. Among the dependent variables in the logistic regression analyses, only albumin and NO(x) were significantly different. In the Kaplan-Meier analyses of mortality, the prognosis of patients in 3rd and 4th quartile of NO(x) was significantly worse than that in 1st or 2nd quartile.

CONCLUSION

NO(x) has potential both as a vascular marker and as a marker for predicting survival in elderly. In the latter role, it may be as effective as albumin.

Energy deficiency in the failing heart: linking increased reactive oxygen species and disruption of oxidative phosphorylation rate

Heart failure is a complex syndrome of numerous dysfunctional components which converge to cause chronic progressive failure of ventricular contractile function and maintenance of cardiac output demand. The aim of this brief review is to highlight some of the mounting evidence indicating that augmented superoxide, related reactive oxygen species and other free radicals contribute to the oxidative stress evident during the progression of heart failure. While much of the source of increased reactive oxygen species is mitochondrial, there are other intracellular sources, which together are highly reactive with functional and structural cellular lipids and proteins. Bioenergetic defects limiting ATP synthesis in the failing myocardium relate not only to post-translational modification of electron transport respiratory chain proteins but also to perturbation of Krebs Cycle enzyme-dependent synthesis of NADH. Accumulation of pathological levels of lipid peroxides relate to dysfunction in the intrinsic capacity to clear and renew dysfunctional proteins. This review also features key limitations of human heart failure studies and potential clinical therapies that target the elevated oxidative stress that is a hallmark of human heart failure.

Tumor-Necrosis-Factor-.ALPHA.-Gene-Deficient Mice Have Improved Cardiac Function Through Reduction of Intercellular Adhesion Molecule-1 in Myocardial Infarction

BACKGROUND

Tumor necrosis factor (TNF)-alpha is linked to the pathogenesis of cardiovascular diseases, but how it affects myocardial infarction (MI), so the present study examined the effects of TNF-alpha and the involvement of intercellular adhesion molecule (ICAM)-1 on MI.

METHODS AND RESULTS

Left coronary arteries of C57BL/6 wild type (WT) and TNF-alpha knockout (KO) mice were ligated and the mice were killed 1, 3, and 7 days later. Fractional shortening on echocardiography of the KO mice was significantly higher than that of the WT mice from day 1 to 7 (p<0.01). The ICAM-1 mRNA in the infarcted area of the KO mice was significantly lower than that of the WT from day 1 (p<0.01) to 7. In immunohistochemistry, the expression of ICAM-1 was weaker in the KO than in the WT mice. The number of neutrophils in the KO mice peaked at day 1, but even this peak level failed to reach the levels in the infarcted (p<0.01) and peri-infarcted areas (p<0.05) in the WT. The number of macrophages in the KO mice peaked at day 7, but this peak level failed to reach the levels in the infarcted (p<0.01) and peri-infarcted areas (p<0.05) in the WT.

CONCLUSION

In a permanent occlusion model of MI TNF-alpha decreased cardiac function and ameliorated myocardial remodeling through the induction of ICAM-1.

Targets for immunomodulation in cardiovascular disease – where are we now?

The recognition that inflammation plays an important role in most cardiovascular pathologies offers the potential for the development of new therapeutic targets. Heart failure and in-stent restenosis are two areas in which there have been very recent developments in identifying and targeting potential inflammatory mediators. The development of both broad anti-inflammatory strategies and more targeted approaches have confirmed that immunomodulation may have a beneficial effect on disease progression of restenosis and heart failure in experimental animals, while the results from clinical studies highlight the need to consider the inflammatory processes as a whole, rather than some aspects in isolation. This review briefly summarizes the key stimuli for initiating inflammation in cardiovascular disease, recent clinical and experimental developments in the search for appropriate anti-inflammatory strategies and considers the possible pitfalls and future challenges for developing this area.

Repeated Sauna Therapy Increases Arterial Endothelial Nitric Oxide Synthase Expression and Nitric Oxide Production in Cardiomyopathic Hamsters

BACKGROUND

Vascular endothelial dysfunction is involved in the pathophysiology of chronic heart failure (CHF). It has been reported that sauna therapy, which allows thermal vasodilation, improves vascular endothelial dysfunction in patients with CHF. The present study investigates the mechanisms through which sauna therapy improves endothelial dysfunction induced by CHF.

METHODS AND RESULTS

Normal control and male TO-2 cardiomyopathic hamsters were used. Thirty-week-old TO-2 hamsters were treated daily with an experimental far infrared-ray dry sauna system for 15 min at 39 degrees C followed by 20 min at 30 degrees C. This procedure raised the rectal temperatures by about 1 degrees C. Arterial endothelial nitric oxide (NO) synthase (eNOS) mRNA and protein expressions were examined, and serum concentrations of nitrate were measured. The expression of eNOS mRNA in the aortas of normal controls did not change, whereas those of the TO-2 hamsters decreased with age. Four weeks of sauna therapy significantly increased eNOS mRNA expression in the aortas of TO-2 hamsters compared with those that did not undergo sauna therapy. Sauna therapy also upregulated aortic eNOS protein expression. Serum nitrate concentrations of the TO-2 hamsters were increased by 4 weeks of sauna therapy compared with those that did not undergo sauna.

CONCLUSION

Repeated sauna therapy increases eNOS expression and NO production in cardiomyopathic hamsters with heart failure.

Impact of left ventricular ejection fraction on endothelial function in patients with coronary artery disease

BACKGROUND

Endothelial dysfunction is present in patients with coronary artery disease (CAD) or with congestive heart failure.

HYPOTHESIS

This study was performed to evaluate the impact of systolic heart function on endothelial function in patients with CAD.

METHODS

The study population consisted of 283 consecutive patients (mean age 59 years, 176 men) undergoing coronary angiography. Endothelial function was assessed by measuring flow-mediated vasodilation (FMD) of the brachial artery.

RESULTS

Patients (n = 236) with an ejection fraction (EF) > or = 55% on routine echocardiogram were younger (mean age 58 vs. 62 years), showed a lower prevalence of diabetes (15 vs. 38%) and myocardial infarction (13 vs. 66%), and showed a higher FMD (4.8 +/- 2.4 vs. 4.0 +/- 2.0%, p < 0.05) than patients (n = 47) with an EF < 55%. The correlation coefficient between FMD/endothelial function and EF/systolic heart function was 0.149 (p < 0.02) in the overall study population. Multivariate analysis showed that of age, gender, frequency of diabetes mellitus, myocardial infarction, and CAD extent, EF was the only significant independent parameter correlating with FMD in patients with CAD.

CONCLUSIONS

Compared with the other tested risk factors, EF surprisingly was the only significant independent parameter correlating with endothelial function in patients with CAD. Our results support the view that endothelial function is an independent prognostic factor in patients with CAD.

Ongoing Myocardial Damage in Chronic Heart Failure is Related to Activated Tumor Necrosis Factor and Fas/Fas Ligand System

BACKGROUND

Elevated concentrations of cardiac troponin T and heart-type fatty acid-binding protein (H-FABP) identify patients with chronic heart failure (CHF) and ongoing myocardial damage (OMD) who are at increased risk for future cardiac events. Cardiomyocyte necrosis and/or apoptosis via activated tumor necrosis factor (TNF) and the Fas/Fas ligand (FasL) system may be related to the development of OMD.

METHODS AND RESULTS

The serum concentrations of H-FABP, a sensitive marker of membrane damage of cardiomyocytes, soluble Fas (sFas) and TNF-alpha were measured in 38 patients with CHF. The concentrations of H-FABP, TNF-alpha and s-Fas in patients with New York Heart Association (NYHA) III + IV were all significantly higher than in those patients in NYHA II (H-FABP; III + IV 9.3+/-5.9 vs II 5.1+/-1.8 ng/ml, p=0.003, TNF-alpha; III + IV 10.5+/-3.8 vs II 8.0+/-2.7 pg/ml, p=0.02, sFas; III + IV 3.36+/-1.37 vs II 2.58 +/-0.84 ng/ml, p=0.03). Increased concentrations of H-FABP significantly correlated with the concentrations of TNF- alpha (r=0.57, p=0.0001) and sFas (r=0.69, p<0.0001), independent of renal function.

CONCLUSION

OMD detected by H-FABP, a marker of membrane damage, is related to activated TNF and the Fas/FasL system, which suggests a pathophysiological role of cardiomyocyte necrosis and/or apoptosis in patients with worsening heart failure.

Randomized, double-blind, placebo-controlled, pilot trial of infliximab, a chimeric monoclonal antibody to tumor necrosis factor-alpha, in patients with moderate-to-severe heart failure: results of the anti-TNF Therapy Against Congestive Heart Failure (ATTACH) trial

BACKGROUND

Preclinical and preliminary clinical data have suggested that tumor necrosis factor-alpha (TNFalpha) may play a role in the evolution and progression of heart failure and that inhibition of TNFalpha may favorably modify the course of the disease. We evaluated the efficacy and safety of infliximab, a chimeric monoclonal antibody to TNFalpha, in patients with moderate-to-severe heart failure.

METHODS AND RESULTS

One hundred fifty patients with stable New York Heart Association class III or IV heart failure and left ventricular ejection fraction <or=35% were randomly assigned to receive placebo (n=49), infliximab 5 mg/kg (n=50), or infliximab 10 mg/kg (n=51) at 0, 2, and 6 weeks after randomization and were followed-up prospectively for 28 weeks. Neither dose of infliximab improved clinical status at 14 weeks, the primary endpoint of the study, despite suppression of inflammatory markers (C-reactive protein and interleukin-6) and a modest increase in ejection fraction in the patients receiving 5 mg/kg (P=0.013). Furthermore, after 28 weeks, 13, 10, and 20 patients were hospitalized for any reason in the placebo, 5 mg/kg infliximab, and 10 mg/kg infliximab groups, respectively. The combined risk of death from any cause or hospitalization for heart failure through 28 weeks was increased in the patients randomized to 10 mg/kg infliximab (hazard ratio 2.84, 95% confidence interval 1.01 to 7.97; nominal P=0.043).

CONCLUSIONS

Short-term TNFalpha antagonism with infliximab did not improve and high doses (10 mg/kg) adversely affected the clinical condition of patients with moderate-to-severe chronic heart failure.