Endotoxin and immune activation in chronic heart failure: a prospective cohort study

Selective intestinal decontamination in advanced chronic heart failure: a pilot trial

BACKGROUND AND AIMS

Endotoxin, derived from intestinal aerobic Gram-negative bacilli (AGNB), could be an important monocyte activator in chronic heart failure (CHF). The effect of selective decontamination of the digestive tract (SDD) on intracellular monocyte cytokine production, monocyte CD14 expression, circulating endotoxin and cytokines, and flow-mediated dilation (FMD) was studied in patients with severe CHF.

METHODS AND RESULTS

Ten patients with CHF (NYHA class III-IV) were enrolled in a non-placebo controlled pilot trial involving the administration of SDD (polymyxin B, tobramycin) for 8 weeks. One patient was later excluded due to cardiac transplantation. Before treatment, after 4 and 8 weeks therapy, and 6 weeks post-treatment, monocyte CD14 expression, intracellular monocyte production of interleukin-1beta [IL-1beta], interleukin-6 [IL-6], tumour necrosis factor (TNF)-alpha with and without lipopolysaccharide (LPS) stimulation were measured. Concentrations of endotoxin and cytokines (IL-1beta, IL-6, TNF-alpha) were also determined. AGNB in faeces, intestinal endotoxin and FMD were assessed at baseline, after 4 weeks of treatment and 6 weeks post-treatment. SDD eradicated intestinal AGNB (P<0.00001) and decreased faecal endotoxin concentrations (P<0.00001). There was a significant decline in monocyte CD14 expression (P=0.03) and in IL-1beta (P=0.0001), IL-6 (P=0.02) and TNF-alpha (P=0.0002) production after 4 and 8 weeks of treatment in the basal state and for IL-1beta (P=0.008) and IL-6 (P=0.005) after LPS stimulation. FMD significantly improved at 4 weeks and returned to baseline after treatment discontinuation (P=0.002). Circulating concentrations of endotoxin and cytokines remained unchanged.

CONCLUSION

Reduction of the intestinal endotoxin pool led to a decrease in monocyte CD14 expression and intracellular cytokine production in patients with severe CHF. The improvement of peripheral endothelial function could be a marker of the anti-inflammatory effect of SDD.

Reverse epidemiology of conventional cardiovascular risk factors in patients with chronic heart failure

Traditional risk factors of a poor clinical outcome and mortality in the general population, including body mass index (BMI), serum cholesterol, and blood pressure (BP), are also found to relate to outcome in patients with chronic heart failure (CHF), but in an opposite direction. Obesity, hypercholesterolemia, and high values of BP have been demonstrated to be associated with greater survival among CHF patients. These findings are in contrast to the well-known associations of over-nutrition, hypercholesterolemia, and hypertension with a poor outcome in the general population. The association between traditional cardiovascular risk factors and an adverse clinical outcome in CHF patients is referred to as "reverse epidemiology." The mechanisms for this inverse association in CHF is not clear. There are other populations with a similar risk factor reversal phenomenon, including patients with end-stage renal disease receiving dialysis, those with advanced malignancies, and individuals with advanced age. Several possible causes are hypothesized: the time discrepancy of the competing risk factors may play a role; the presence of the "malnutrition-inflammation complex syndrome" in CHF patients may explain the existence of reverse epidemiology; and a decreased level of lipoprotein molecules may distort their endotoxin-scavenging role, predisposing CHF patients with a low serum cholesterol level to inflammatory consequences of endotoxemia. It is possible that new goals for such traditional risk factors as BMI, serum cholesterol, and BP should be developed for CHF. Reverse epidemiology of conventional cardiovascular risk factors is observed in CHF and may have a bearing on the management of these patients; thus, it deserves further investigation.

Studies on intragastric PCO2at rest and during exercise as a marker of intestinal perfusion in patients with chronic heart failure

AIMS

The aim of this study was to investigate mesenteric ischaemia by determining intragastric PCO(2) (iPCO(2)) with gastric tonometry during rest and exercise stress testing in patients with chronic heart failure (CHF). In CHF inflammatory immune activation is hypothesized to result from a chronic endotoxin challenge due to bacterial translocation of hypoperfused intestinal mucosa.

METHODS AND RESULTS

In 10 patients with CHF and ten healthy controls a tonometry catheter was inserted into the stomach. IPCO(2) was measured at rest and during bicycle exercise every 5 min. At rest arterial pCO(2) (aPCO(2)), intragastric pCO(2) (iPCO(2)) and the intragastric/arterial gap did not differ between patients and controls. During low level exercise (25 W), patients showed an increase in iPCO(2) compared to resting iPCO(2), whereas controls did not show an increase in iPCO(2) (change in iPCO(2): 12+/-2% vs. 1+/-0.4%, P<0.001). In CHF, iPCO(2) during peak exercise was 25+/-3% higher than at rest, compared to controls (increase 2+/-1, P<0.0001).

CONCLUSIONS

Patients with CHF already at low level exercise develop an increase in iPCO(2). This is likely to reflect hypoperfusion of the intestinal mucosa, which may contribute to the development of bacterial translocation.

Effects of exogenous ubiquitin in lethal endotoxemia

BACKGROUND

Recent data indicated a potential role for extracellular ubiquitin in hematopoiesis and inflammation. The biological significance and therapeutic potential of these findings in vivo are unknown. Based on its in vitro abilities to inhibit endotoxin-stimulated tumor necrosis factor alpha (TNFalpha) production, we hypothesized that exogenous ubiquitin has salutary effects on sequelae caused by endotoxin in vivo.

METHODS

Anesthetized and mechanically ventilated swine were infused with endotoxin for 3 hours. Ubiquitin was administered intravenously either 15 minutes before or 45 minutes after the endotoxin infusion was started. Albumin was administered to a control group. An additional control group received only ubiquitin. Ex vivo endotoxin evoked TNFalpha production was measured using a whole blood assay. Ubiquitin and TNFalpha concentrations were determined by enzyme-linked immunosorbent assay.

RESULTS

Ubiquitin reduced mortality (P <.05), prevented development of pulmonary failure (P <.05), reduced fluid requirements (P <.05), and diminished erythema and edema formation. Ubiquitin pretreatment was more effective than treatment 45 minutes after an endotoxin infusion was started. In vivo ubiquitin administration alone inhibited ex vivo endotoxin-evoked TNFalpha secretion, but had no effect on TNFalpha serum levels after endotoxin infusion.

CONCLUSION

In vivo ubiquitin administration has salutary actions during lethal endotoxemia and inhibits ex vivo whole blood TNFalpha production upon endotoxin stimulation. The clinical appearance after ubiquitin treatment in endotoxemia indicates the endothelium as another potential target cell population for interactions with ubiquitin. A novel therapeutic approach to a broad variety of diseases, in which endotoxin triggers immune activation, is suggested.

Nutritional strategy in the management of heart failure in adults

The incidence of congestive heart failure (CHF) is increasing in Westernized countries, and patients with CHF experience poor quality of life (functional impairment, high hospitalization rate and high mortality). Malnutrition occurring during the course of CHF is referred to as cardiac cachexia and is associated with higher mortality independent of the severity of CHF. Cardiac cachexia involving a loss of more than 10% of lean body mass can clinically be defined as a bodyweight loss of 7.5% of previous dry bodyweight in a period longer than 6 months. The energy requirements of patients with CHF, whether cachectic or not, are not noticeably modified since the increase in resting energy expenditure is compensated by a decrease in physical activity energy expenditure. Malnutrition in CHF has been ascribed to neurohormonal alterations, i.e. anabolic/catabolic imbalance and increased cytokine release. Anorexia may occur, particularly during acute decompensation of CHF. Function is impaired in CHF, because of exertional dyspnea and changes in skeletal muscle. Decreased exercise endurance seems to be related to decreased mitochondrial oxidative capacities and atrophy of type 1 fibers, which are attributed to alteration in muscle perfusion and are partially reversible by training. Malnutrition could also impair muscle function, because of decreased muscle mass and strength associated with decreased glycolytic capacities and atrophy of type 2a and 2b fibres. With respect to the putative mechanisms of cardiac cachexia, anabolic therapy (hormones or nutrients) and anticytokine therapy have been proposed, but trials are scarce and often inconclusive. In surgical patients with CHF, perioperative (pre- and postoperative) nutritional support has been shown to be effective in reducing the mortality rate. Long term nutritional supplementation trials in patients with CHF and cachexia are thus required to establish recommendations for the nutritional management of patients with CHF.

Endotoxin sensitivity and immune competence in chronic heart failure

BACKGROUND

Raised concentrations of endotoxin (lipopolysaccharide, LPS) are found in patients with chronic heart failure (CHF). Tolerance of monocytes to LPS can be induced by LPS itself resulting in a downregulation of cytokine response to LPS challenge. This phenomenon of LPS desensitization has also been suggested for CHF.

METHODS

We investigated whether CHF patients really show a desensitization to LPS stimuli at rest or after physical exercise, which was used as a model of limited inflammatory reaction. Thirty-five patients with CHF (59+/-12 years, 8 women) and 30 healthy control subjects were prospectively studied with cardiopulmonary exercise testing. At rest and directly after exercise blood samples were taken for the quantitative determination of HLA-DR expression of monocytes as a measure for immune competence and for the measurement of TNFalpha generation after ex vivo stimulation by LPS.

RESULTS

HLA-DR expression was comparable in CHF patients and controls at rest as well as after exercise. TNFalpha production by LPS-stimulated monocytes ex vivo was higher in CHF patients compared to controls at rest and after exercise.

CONCLUSIONS

Thus, our data are the first to show that patients with stable CHF show a cellular hypersensitivity to LPS with a higher TNFalpha generation capacity at rest and after exercise compared to controls. CHF patients seem to have a marked susceptibility to low inflammatory stimuli and no desensitization to LPS.

Invasive assessment of bacterial endotoxin and inflammatory cytokines in patients with acute heart failure

AIMS

To test the hypothesis that during acute heart failure endotoxin might be increased in hepatic veins as a sign of bacterial or endotoxin translocation from the bowel into the blood stream.

METHODS AND RESULTS

In patients with acute heart failure (NYHA IV; n=17) levels of endotoxin, soluble (s) CD14, tumor necrosis factor alpha (TNFalpha and interleukin 6 (IL6)) were measured in blood drawn from an antecubital vein on admission and compared with age-matched patients with stable chronic heart failure (n=21) and healthy volunteers (n=9). All levels were systemically elevated during acute heart failure (all P<0.05); once patients were stable enough to undergo cardiac catheterization, endotoxin was found to be significantly higher in hepatic veins (0.62+/-0.05 EU/ml) than left ventricles (0.46+/-0.04 EU/ml; P<0.05), whereas sCD14, TNFalpha and IL6 were not different between these sites. At follow-up (29+/-6 days) endotoxin but not sCD14, TNFalpha or IL-6 was significantly lower as compared to baseline (P<0.05).

CONCLUSIONS

Higher levels of endotoxin in hepatic veins as compared to the left ventricle during acute heart failure are suggestive of bacterial or endotoxin translocation from the bowel into the blood stream. This may lead to new treatment strategies. The lack of difference in TNFalpha levels between the pulmonary artery and the left ventricle sheds doubt on the heart as a source of systemically elevated TNFalpha levels.

Glutamate synthase: a fascinating pathway from L-glutamine to L-glutamate

Glutamate synthase is a multicomponent iron-sulfur flavoprotein belonging to the class of N-terminal nucleophile amidotransferases. It catalyzes the conversion of L-glutamine and 2-oxoglutarate into two molecules of L-glutamate. In recent years the X-ray structures of the ferredoxin-dependent glutamate synthase and of the a subunit of the NADPH-dependent glutamate synthase have become available. Thanks to X-ray crystallography, it is now known that the ammonia reaction intermediate is transferred via an intramolecular tunnel from the amidotransferase domain to the synthase domain over a distance of about 32A. Although ammonia channeling is a recurrent theme for N-terminal nucleophile and triad-type amidotransferases, the molecular mechanisms of ammonia transfer and its control are different for each known amidotransferase. This review focuses on the intriguing mechanism of action and self-regulation of glutamate synthase with a special focus on the structural data.

Searching for links between endotoxin exposure and pregnancy loss: CD14 polymorphism in idiopathic recurrent miscarriage

PROBLEM

Lipopolysaccharide (LPS) (endotoxin) is a well-known inducer of abortions in mice. In addition it has been proposed that gut-derived LPS of gram-negative bacteria may play a role in triggering idiopathic recurrent miscarriage (IRM) in humans. CD14 is one of the key molecules that mediates the effects of LPS. Promoter region polymorphism (-159C/T) in the CD14 gene is functionally important by regulating CD14 levels. High-producing CD14 genotype (TT) associates with deleterious effects of gut-derived LPS in hepatic cirrhosis in humans. It is not known whether women with IRM are genetically more prone to suffer from toxic effects of LPS.

METHOD OF STUDY

By using polymerase chain reaction we analyzed the CD14 promoter region polymorphism in 38 women with IRM and in 127 normal controls of Finnish origin.

RESULTS

There were no significant differences in the CD14 (-159C/T) allele or the genotype frequencies between the IRM women and the controls. However, there was a trend associating the presence of the T allele with increased odds of miscarriage.

CONCLUSIONS

Although we were not able to find a statistically significant association between CD14 genotypes and IRM in our relatively small study population, a further study with a larger sample size is warranted to explore the role of high-producing CD14 genotypes in IRM. Also studies highlighting environmental LPS triggers and other intrinsic mediators of LPS signalling are needed to solve the enigmatic role of LPS in IRM in humans.

Inflammation in uremic patients: what is the link?

Uremic patients suffer to an extremely high degree from cardiovascular disease. Cardiovascular disease results mainly from atherosclerotic remodeling of the arterial system. Inflammation is considered to contribute significantly to development of atherosclerosis, and albeit many different factors may lead to inflammation, generation of enhanced oxidative stress is believed to be an important common feature of pro-inflammatory causes. Studies in the general population without renal disease could clearly show that markers of inflammation, in particular C-reactive protein, predict the cardiovascular risk. In this review article, we discuss the presence and the predictive value of inflammation in patients with end-stage renal disease, and analyze whether uremic patients are exposed to specific pro-inflammatory and pro-oxidative conditions. Particular emphasis is set on oxidative stress induced by oxidatively modified lipoproteins and angiotensin II. Based on pathophysiological considerations valid for uremic patients, we discuss therapeutical options that might help to reduce cardiovascular disease in uremic patients.

Cardiac cachexia

Chronic heart failure (CHF) remains an important and increasing public health care problem. It is a complex syndrome affecting many body systems. Body wasting (i.e., cardiac cachexia) has long been recognised as a serious complication of CHF. Cardiac cachexia is associated with poor prognosis, independently of functional disease severity, age, and measures of exercise capacity and cardiac function. Patients with cardiac cachexia suffer from a general loss of fat tissue, lean tissue, and bone tissue. Cachectic CHF patients are weaker and fatigue earlier, which is due to both reduced skeletal muscle mass and impaired muscle quality. The pathophysiologic alterations leading to cardiac cachexia remain unclear, but there is increasing evidence that metabolic, neurohormonal and immune abnormalities may play an important role. Cachectic CHF patients show raised plasma levels of epinephrine, norepinephrine, and cortisol, and they show high plasma renin activity and increased plasma aldosterone level. Several studies have also shown that cardiac cachexia is linked to raised plasma levels of tumour necrosis factor alpha and other inflammatory cytokines. The degree of body wasting is strongly correlated with neurohormonal and immune abnormalities. The available evidence suggests that cardiac cachexia is a multifactorial neuroendocrine and metabolic disorder with a poor prognosis. A complex imbalance of different body systems may cause the development of body wasting.

Therapeutic potential of anticytokine therapy in congestive heart failure

Accumulating evidence indicates that inflammatory cytokines play a pathogenic role in congestive heart failure (CHF) by influencing heart contractility, inducing hypertrophy, and promoting apoptosis or fibrosis, contributing to the continuous myocardial remodeling process. While several stimuli may be operating such as heat-shock protein, microbial antigen, bacterial lipopolysaccharide, shear and oxidative stress, hypoxia and oxidized low-density lipoprotein (LDL), it seems that the inflammatory response to these stimuli may represent a common final pathogenic pathway in CHF regardless of the initial event. Traditional cardiovascular drugs seem to have little influence on the overall cytokine network, and immunomudulatory therapy has emerged as a possible new treatment modality in CHF. Several animal studies, and some clinical pilot studies, have suggested that down-regulation of inflammatory cytokines may improve cardiac performance. On the other hand, preliminary results from the placebo-controlled studies suggest no effect, or even adverse effect, of antitumor necrosis factor (TNF) therapy on mortality and hospitalization. Although somewhat disappointing, these negative results do not necessarily argue against the 'cytokine hypothesis'. These studies just underscore the difficulties and the challenges in developing treatment modalities that can modulate the cytokine network in CHF patients resulting in anti-inflammatory and beneficial net effects. Further research in this area will have to more precisely identify the most important actors in the immunopathogenesis of CHF in order to develop more specific immunomodulating agents for this disorder. However, at present the beneficial role of anticytokine therapy in patients with CHF remains unproven.

Change in circulating cytokines after 2 forms of exercise training in chronic stable heart failure

BACKGROUND

A proinflammatory state is recognized in chronic heart failure and the degree of immune activation corresponds to disease severity and prognosis. Training is known to improve symptoms in heart failure but less is known about the effects of specific forms of training on the proinflammatory state.

METHODS

Forty-six patients with stable chronic heart failure underwent a home-based program of exercise training for 30 minutes a day, 5 days per week over a 6-week period. Twenty-four used a bicycle ergometer and 22 used an electrical muscle stimulator applied to quadriceps and gastrocnemius muscles. Tumour necrosis factor-alpha (TNF-alpha), TNF-alpha soluble receptors 1 and 2, interleukin 6, and C-reactive protein were measured before and after the training period.

RESULTS

Significant improvements in markers of exercise performance were seen in both training groups. Soluble TNF-alpha receptor 2 levels decreased after training in the bike group only (2900 +/- 1069 pg/mL to 2625 +/- 821 pg/mL, P =.013). Trends towards a decrease in levels of TNF-alpha and soluble receptor 1 were also seen in the bike group only. No change in circulating inflammatory markers was observed after stimulator training.

CONCLUSIONS

Physical training improves exercise capacity for patients with chronic heart failure but degree of attenuation of the proinflammatory response may depend on the mode of training despite similar improvements in exercise capacity.

The relationship between cholesterol and survival in patients with chronic heart failure

OBJECTIVES

We sought to describe the relationship between cholesterol and survival in patients with chronic heart failure (CHF).

BACKGROUND

Increasing lipoprotein levels are a cardiovascular risk factor. In patients with CHF, the prognostic value of endogenous lipoproteins is not fully clarified.

METHODS

A group of 114 patients with CHF recruited to a metabolic study was followed for a minimum of 12 months (derivation study). The results were applied to a second group of 303 unselected patients with CHF (validation study). The relationship between endogenous lipoproteins and survival was explored.

RESULTS

In the derivation study, survival at 12 months was 78% (95% confidence interval [CI] 70% to 86%) and 56% (95% CI 51% to 62%) at 36 months. Increasing total serum cholesterol was a predictor of survival (hazard ratio 0.64, 95% CI 0.48 to 0.86), independent of the etiology of CHF, age, left ventricular ejection fraction, and exercise capacity. Receiver-operating characteristic curves demonstrated a best cut-off value of </=5.2 mmol/l (200.8 mg/dl) as being the best predictor of mortality at 12 months (sensitivity 80.0%, specificity 62.9%). In the validation population, one-year survival was 88% (95% CI 84 to 91%) and three-year survival was 68% (95% CI 63 to 73%). The chance of survival increased 25% for each mmol/l increment in total cholesterol. Survival rates above and below the cut-off value for cholesterol in patients with ischemic heart disease (n = 181) were 92% (95% CI 89 to 94) versus 75% (95% CI 64 to 85%) at one year and 72% (95% CI 67 to 76%) versus 50% (95% CI 43 to 56%) at three years.

CONCLUSIONS

In patients with CHF, lower serum total cholesterol is independently associated with a worse prognosis.

Preoperative C-reactive protein and outcome after coronary artery bypass surgery

BACKGROUND

C-reactive protein (CRP) is a predictor of early and late outcome after coronary angioplasty, but there is scant data on its impact on the outcome after coronary artery bypass grafting (CABG).

METHODS

The predictive value of preoperative CRP was evaluated in a series of 764 patients who underwent on-pump CABG.

RESULTS

During the in-hospital stay, 13 patients (1.7%) died, 45 (4.5%) developed low cardiac output syndrome, and 28 (3.7%) suffered minor or major cerebrovascular complications. Patients with a preoperative serum concentration of CRP>/=1.0 mg/dL had a higher risk of overall postoperative death (5.3% vs 1.1%, p = 0.001), cardiac death (4.4% vs 0.8%, p = 0.002), low cardiac output syndrome (8.8% vs 3.7%, p = 0.01), and any cerebrovascular complication (4.4% vs 3.5%, p = 0.66). Preoperative serum concentration of CRP>/=1.0 mg/dL was significantly more frequent among patients with history of myocardial infarction, diabetes, lower limb ischemia, low left ventricular ejection fraction, NYHA class IV, and in those undergoing urgent or emergency operation. At multivariate analysis, preoperative serum concentration of CRP >/= 1.0 mg/dL (p = 0.01, O.R.: 6.97) and left ventricular ejection fraction (p = 0.01, O.R.: 0.95) were independent predictors of postoperative death. Postoperative mortality rate was 0.3% among patients with preoperative CRP < 1.0 mg/dL and an ejection fraction >/=50%, whereas it was 21.4% among those with a preoperative CRP >/= 1.0 mg/dL and an ejection fraction less than 50% (p < 0.0001).

CONCLUSIONS

Preoperative serum concentration of CRP in patients undergoing on-pump coronary artery bypass surgery is an important determinant of postoperative outcome.

Do All Nonsurvivors of Cardiogenic Shock Die With a Low Cardiac Index? *

STUDY OBJECTIVES

To characterize the hemodynamic course of cardiogenic shock and to relate the cause of death to ongoing cardiac failure or multiple organ dysfunction.

DESIGN

Retrospective study.

SETTING

A 31-bed department of intensive care in a university hospital.

PATIENTS

All patients admitted for cardiogenic shock from January 1999 to December 2000.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Charts were reviewed for demographic, clinical, hemodynamic, oxygen transport, inflammation, and organ dysfunction data. Of 62 patients with cardiogenic shock, 40 (65%) did not survive. Eight patients (20%) died from fatal arrhythmia, 14 patients (35%) died with low cardiac index (CI) [ie, < 2.2 L/min/m(2)], and 18 patients (45%) died with normalized CI (ie, > 2.2 L/min/m(2)) and a higher CI/oxygen extraction ratio. Of these 18 patients, 9 had evidence of infection. The patients with normalized CI were younger and stayed longer in the ICU than patients with low CI.

CONCLUSION

A substantial number of patients with cardiogenic shock die with a normalized CI, suggesting a distributive defect, in the absence of obvious infection. These patients are younger and have a longer ICU course. The release of mediators may be secondary to gut hypoperfusion.

sICAM-1 correlates with myocardial ICAM-1 expression in dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is etiopathogenically linked to intramyocardial inflammation, which is reflected by ICAM-1 abundance. We investigated whether soluble ICAM-1 (sICAM-1) levels in the sera of DCM patients are associated with intramyocardial ICAM-1 expression.

METHODS

Immunohistochemically detected ICAM-1 expression was quantified semiquantitatively in endomyocardial biopsies from DCM patients (n=45; n=17 females; age: 48+/-15 years) and from n=12 donor hearts (controls) by a human observer (baseline vs. enhanced expression) and quantitatively by a digital image analysis (DIA) system. The DIA-measured qualities were area fraction (AF), surface-volume ratio (SVR) and integral optical density (ID). The sICAM-1 levels of the DCM patients and n=12 healthy volunteers (controls) were measured by ELISA (means of duplicate measurements). Intramyocardial ICAM-1 expression and sICAM-1 levels were compared in these DCM patients.

RESULTS

Of the DCM patients, n=24 (53%) demonstrated statistically higher sICAM-1 levels compared to controls (>198 ng/ml). By semiquantitative and quantitative DIA evaluation, endothelial ICAM-1 abundance was present in n=25 (56%) of the DCM biopsies. sICAM-1 correlated significantly (P<0.001) both with the semiquantitatively assessed and the DIA-measured ICAM-1-AF, the ICAM-1-SVR and the ICAM-1-ID. The positive predictive value of sICAM-1 measurements for intramyocardial ICAM-1 abundance was 96%, and the negative predictive value was 71%, with a receiver operating characteristic area under the curve of 0.93. Furthermore, sICAM-1 levels correlated with intramyocardial T-lymphocytic (CD2+/CD3+) infiltrates (P<0.03).

CONCLUSIONS

Measurement of non-invasively obtained sICAM-1 reliably reflects intramyocardial ICAM-1 expression and may therefore serve as a non-invasive marker of inflammatory activity in DCM.

Interleukin-6, tissue factor and von Willebrand factor in acute decompensated heart failure: relationship to treatment and prognosis

Arterial thrombotic and thromboembolic complications are increased in congestive heart failure (CHF), and are a particular problem in acute decompensated heart failure, which carries a poor prognosis. As interleukin-6 (IL-6) has been shown to induce the potent procoagulant tissue factor (TF) in experimental models, we hypothesized that the pro-inflammatory IL-6 may be one mechanism contributing to thrombosis in heart failure, mediated via endothelial expression of TF on activated/damaged cells [indicated by plasma von Willebrand factor (vWF)]. Seventy-seven patients (67% men, New York Heart Association class III-IV, 87%) with acute CHF were recruited, and were compared with 53 chronic stable CHF patients in sinus rhythm (66% men, New York Heart Association class III-IV, 2%) and 37 healthy controls (68% men). Acute CHF patients in sinus rhythm had elevated baseline levels of IL-6 (P < 0.0001), TF (P = 0.041) and vWF (P < 0.0001) (all measured by enzyme-linked immunosorbent assay) compared with both chronic CHF and healthy control groups. A correlation exists in acute CHF between baseline TF and IL-6 (Spearman r = 0.64, P < 0.0001). After 3 months treatment, with control or alleviation of heart failure symptoms in 40 patients, there was a fall in levels of IL-6 (P < 0.0001) and vWF (P < 0.0001), but levels still remained significantly higher than healthy controls. Patients who died at 6 months follow-up also had higher baseline levels of IL-6 (P = 0.008), TF (P = 0.037) and vWF (P = 0.039) when compared with those who remained alive. Elevated IL-6 may contribute to the thrombotic and thromboembolic complications in acute heart failure, in a process mediated via increased TF and vWF. Improvement of symptoms and plasma markers after treatment of acute CHF and prediction of prognosis by the markers may be useful in the clinical setting.

IRAK1 deletion disrupts cardiac Toll/IL-1 signaling and protects against contractile dysfunction

Myocardial contractile dysfunction accompanies both systemic and cardiac insults. Septic shock and burn trauma can lead to reversible contractile deficits, whereas ischemia and direct inflammation of the heart can precipitate transient or permanent impairments in contractility. Many of the insults that trigger contractile dysfunction also activate the innate immune system. Activation of the innate immune response to infection is coordinated by the conserved Toll/interleukin-1 (IL-1) signal transduction pathway. Interestingly, components of this pathway are also expressed in normal and failing hearts, although their function is unknown. The hypotheses that Toll/IL-1 signaling occurs in the heart and that intact pathway function is required for contractile dysfunction after different insults were tested. Results from these experiments demonstrate that lipopolysaccharides (LPS) activate Toll/IL-1 signaling and IL-1 receptor-associated kinase-1 (IRAK1), a critical pathway intermediate in the heart, indicating that the function of this pathway is not limited to immune system tissues. Moreover, hearts lacking IRAK1 exhibit impaired LPS-triggered downstream signal transduction. Hearts from IRAK1-deficient mice also resist acute LPS-induced contractile dysfunction. Finally, IRAK1 inactivation enhances survival of transgenic mice that develop severe myocarditis and lethal heart failure. Thus the Toll/IL-1 pathway is active in myocardial tissue and interference with pathway function, through IRAK1 inactivation, may represent a novel strategy to protect against cardiac contractile dysfunction.

Serum but not myocardial TNF-alpha concentration is increased in pacing-induced heart failure in rabbits

In animals and patients with severe heart failure (HF), the serum tumor necrosis factor-alpha (TNF-alpha) concentration is increased. It is, however, still controversial whether or not such increased serum TNF-alpha originates from the heart itself or is of peripheral origin secondary to gastrointestinal congestion and increased endotoxin concentration. We therefore now examined TNF-alpha in serum, myocardium, and liver of sham-operated and HF rabbits. In nine rabbits in which HF was induced by left ventricular (LV) pacing at 400 beats/min for 3 wk, LV end-diastolic diameter was increased and systolic shortening fraction (9.4 +/- 1.0 vs. 28.5 +/- 1.3%, echocardiography, P < 0.05) was reduced. Serum TNF-alpha was higher in HF than in sham-operated rabbits (240 +/- 24 vs. 150 +/- 22 U/ml, WEHI-cell assay, P < 0.05). In the heart, TNF-alpha was located mainly in the vascular endothelium (immunohistochemistry), and TNF-alpha protein (920 +/- 160 vs. 900 +/- 95 U/g) did not differ between groups. In the liver of HF rabbits, hepatocytes expressed TNF-alpha, and TNF-alpha protein was increased compared with sham-operated rabbits (2,390 +/- 310 vs. 1,220 +/- 135 U/g, P < 0.05) and correlated to the number of hepatic leukocytes (r = 0.85) and serum TNF-alpha (r = 0.69). The intestinal endotoxin concentration was 24.5 +/- 1.2 vs. 17.0 +/- 3.1 endotoxin units/g wet wt (P < 0.05) in HF compared with sham-operated rabbits. In this HF model, serum but not myocardial TNF-alpha is increased. The increased serum TNF-alpha originates from peripheral sources.

The relationship between age and production of tumour necrosis factor-alpha in healthy volunteers and patients with chronic heart failure

BACKGROUND

Ageing is associated with an altered immune response. Elevated plasma levels of tumour necrosis factor-alpha (TNF-alpha) are present in patients with advanced chronic heart failure (CHF). However, the relationship between age and the immune response in CHF is unknown.

METHODS

We investigated the relationship between age and the TNF-alpha generating capacity of lipopolysaccharide (LPS) stimulated peripheral blood mononuclear cells (PBMC) in nine healthy control subjects (mean age 51.6+/-3.6 years, age range 39-75 years) and 22 stable patients with CHF (mean age 68.3+/-1.5 years, age range 52-78 years, NYHA class 3.0+/-0.2). We also tested the TNF-alpha generating capacity of all control subjects and 18 CHF patients in whole blood cultures.

RESULTS

Subjects were subgrouped according to baseline TNF-alpha secretion in PBMC cultures into low- and high-responders, with the latter producing TNF-alpha even without LPS stimulation. High-responders produced more TNF-alpha than low-responders at all LPS doses (0.001-10 ng/ml, P<0.0001, repeated measures ANOVA), and high-responders were significantly older than low-responders (controls: 65.8+/-9.2 vs. 47.5+/-2.5 years; patients: 71.9+/-1.9 vs. 65.9+/-1.9 years, both P<0.05). Age correlated with TNF-alpha production in both patients and controls. This effect was independent of NYHA class.

CONCLUSIONS

LPS-responsiveness appears to relate to age in both healthy controls and CHF patients. When assessing the immune status of CHF patients, age should therefore be considered an important confounding factor. In whole blood these findings could only be confirmed at the highest LPS concentration used, thus suggesting that certain factors in the blood may be able to abolish LPS activity at lower concentrations.

Elevated circulating levels of inflammatory cytokines and bacterial endotoxin in adults with congenital heart disease

Chronic heart failure is a state of immune activation, and endotoxin is a potential trigger for cytokine production. Our aim was to study whether immune activation and endotoxemia occur in adults with congenital heart disease. We prospectively measured tumor necrosis factor (TNF)-alpha, soluble TNF receptors (sTNFR-1, sTNFR-2), interleukin-6, interleukin-10, endotoxin, and soluble CD14 levels in 52 consecutive adults with congenital heart disease (age 34 +/- 2 years [mean +/- SEM]) and 18 healthy controls (age 31 +/- 1 years). A variety of congenital heart lesions were studied: single ventricle physiology (n = 15), systemic right ventricle (n = 7), tetralogy of Fallot (n = 20), and "other" congenital heart disease (n = 10). Patients were subgrouped into asymptomatic (New York Heart Association [NYHA] class I, n = 11), mild (NYHA class II, n = 30), and moderate/severe (NYHA class III/IV, n = 11) categories. Patients had elevated TNF and interleukin-6 levels compared with controls (TNF 2.8 vs 2.1 pg/ml, p <0.05; interleukin-6 8.5 vs 5.7 pg/ml, p <0.001). TNF levels were higher in patients with moderate/severe symptoms compared with patients who were asymptomatic or had mild symptoms (p <0.05). Soluble TNFR-1 levels related directly to the degree of systemic ventricular impairment (p <0.05). There were no significant differences in sTNFR-1, sTNFR-2, interleukin-10, or sCD14 levels between patients and controls. Endotoxin levels were greater in patients with congenital heart disease versus controls (0.40 vs 0.26 endotoxin units/ml, p <0.0001). Thus, adults with congenital heart disease have elevated levels of inflammatory cytokines and bacterial endotoxin, which relate to functional status. Congenital heart disease in adults may be amenable to novel anti-inflammatory therapies in selected patients.

Demographics and concomitant disorders in heart failure

Chronic heart failure is an increasingly common cause of premature death and poor quality of life. Community-based epidemiological studies have provided much-needed information on the demography of chronic heart failure, providing insight into its influence on public health. In most patients, chronic heart failure is accompanied by a range of concomitant disorders that both contribute to the cause of the disease and have a key role in its progression and response to treatment. Information on the most common comorbidities in chronic heart failure--ischaemic heart disease, hypertension, and diabetes mellitus--is presented for prespecified subgroups in the reports of many large-scale, multicentre trials; despite their limitations, these subanalyses provide guidance in therapeutic decision-making. Similarly, because chronic heart failure is commonly an endpoint in intervention trials of both hypertension and diabetes, such studies afford important information on the prevention of chronic heart failure in these common diseases.

Is a single time point C-reactive protein predictive of outcome in peritoneal dialysis patients?

C-reactive protein is the prototype marker of inflammation and has been shown to predict mortality in hemodialysis patients. However, it remains uncertain as to whether a single C-reactive protein level has similar prognostic significance in peritoneal dialysis patients. A single high-sensitivity C-reactive protein (hs-CRP) level was measured in 246 continuous ambulatory peritoneal dialysis patients without active infections at study baseline together with indices of dialysis adequacy, echocardiographic parameters (left ventricular mass index, left ventricular dimensions, and ejection fraction), nutrition markers (serum albumin, dietary intake, and subjective global assessment) and biochemical parameters (hemoglobin, lipids, calcium, and phosphate). The cohort was then followed-up prospectively for a median of 24 mo (range, 2 to 34 mo), and outcomes were studied in relation to these parameters. Fifty-nine patients died (36 from cardiovascular causes) during the follow-up period. The median hs-CRP level was 2.84 mg/L (range, 0.20 to 94.24 mg/L). Patients were stratified into tertiles according to baseline hs-CRP, namely those with hs-CRP < or = 1.26 mg/L, 1.27 to 5.54 mg/L, and > or = 5.55 mg/L. Those with higher hs-CRP were significantly older (P < 0.001), had greater body mass index (P < 0.001), higher prevalence of coronary artery disease (P = 0.003), and greater left ventricular mass index (P < 0.001). One-year overall mortality was 3.9% (lower) versus 8.8% (middle) versus 21.3% (upper tertile) (P < 0.0001). Cardiovascular death rate was 2.7% (lower) versus 5.2% (middle) versus 16.2% (upper tertile) (P < 0.0001). Multivariable Cox regression analysis showed that every 1 mg/L increase in hs-CRP was independently predictive of higher all-cause mortality (hazard ratio [HR], 1.02; 95% CI, 1.01 to 1.04; P = 0.002) and cardiovascular mortality (HR, 1.03; 95% CI, 1.01 to 1.05; P = 0.001) in peritoneal dialysis patients. Other significant predictors for all-cause mortality included age (HR, 1.07; 95% CI, 1.04 to 1.10), gender (HR, 0.49; 95% CI, 0.27 to 0.90), atherosclerotic vascular disease (HR, 2.65; 95% CI, 1.46 to 4.80), left ventricular mass index (HR, 1.01; 95% CI, 1.00 to 1.01) and residual GFR (HR, 0.53; 95% CI, 0.38 to 0.75). Age (HR, 1.06; 95% CI, 1.02 to 1.10), history of heart failure (HR, 3.31; 95% CI, 1.36 to 8.08), atherosclerotic vascular disease (HR, 3.20; 95% CI, 1.43 to 7.13), and residual GFR (HR, 0.57; 95% CI, 0.38 to 0.86) were also independently predictive of cardiovascular mortality. In conclusion, a single, random hs-CRP level has significant and independent prognostic value in PD patients.

Anemia predicts mortality in severe heart failure: the prospective randomized amlodipine survival evaluation (PRAISE)

OBJECTIVES

Our aim was to examine the relationships between serum hematocrit (Hct) and risk of all-cause mortality among patients with severe heart failure (HF).

BACKGROUND

Anemia occurs with increased frequency in severe HF. However, few studies have examined the impact of anemia on mortality in this population.

METHODS

Using a prospective cohort design, we evaluated the relationships between baseline serum Hct and mortality among 1,130 patients with left ventricular EF <30% and New York Heart Association functional class IIIB or IV HF treated with angiotensin-converting enzyme inhibitors, diuretics, and digitalis. Mortality was ascertained by centralized adjudication.

RESULTS

The mean Hct was 41.8% (range 25.4% to 58.8%). Over 15 months of mean follow-up, there were 407 deaths (29 per 100 person-years). After adjustment for potential confounders, those in the lowest quintile of Hct (range 25.4% to 37.5%) had a 52% higher risk of death (hazard ratio 1.52, 95% confidence interval 1.11 to 2.10), compared with the highest quintile (range 46.1% to 58.8%). Within the lowest quintile of Hct, each 1% decrease in Hct was associated with an 11% higher risk of death (p < 0.01), whereas within the four higher quintiles of Hct, Hct was not associated with total mortality. Evaluation of different causes of death indicated that a lower Hct was strongly associated with death from progressive HF, rather than sudden death or other deaths.

CONCLUSIONS

Among patients with severe HF, anemia is a significant independent risk factor for death, with a progressively higher risk with increasing severity of anemia. Further investigation of the etiologies, prevention, and treatment of anemia in severe HF is warranted.

Elevated plasma amylase levels in advanced chronic heart failure secondary to ischemic or idiopathic dilated cardiomyopathy: correlation with circulating interleukin-6 activity

It has been reported that proinflammatory cytokine activation is associated with both mesenteric venous congestion and peripheral tissue underperfusion in advanced chronic heart failure. The aim of our study was to investigate if plasma amylase (as an easily approached marker of a low-grade peripheral organ injury caused by elevated systemic venous pressure and reduced cardiac output) is elevated in severe heart failure and if this elevation is correlated with cytokine and neurohormonal activation in the plasma of heart failure patients. Plasma levels of amylase, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF), norepinephrine, and renin activity were measured in 43 severe heart failure patients (ischemic, 28; dilated, 15; left ventricular ejection fraction [LVEF] 27 +/- 3%; New York Heart Association [NYHA] classes III-IV), in 37 mild heart failure patients (ischemic, 26; dilated, 11; LVEF, 33 +/- 5%; NYHA classes I-II), and in 20 age-matched and gender-matched healthy controls. NYHA III-IV heart failure patients exhibited significantly higher plasma levels of amylase (342 +/- 19 vs. 174 +/- 13 U/L, p < 0.01), TNF-alpha (6.2 +/- 0.5 vs. 4.2 +/- 0.3 pg/ml, p < 0.01), IL-6 (5.9 +/- 0.3 vs. 4.4 +/- 0.3 pg/ml, p < 0.05), GM-CSF (21.2 +/- 2.7 vs. 4.1 +/- 0.9 pg/ml, p < 0.001), and neurohormones (both p < 0.001) compared with NYHA I-II heart failure patients and healthy controls (amylase, 165 +/- 11 U/L, p < 0.01; TNF-alpha, 2.7 +/- 0.3 pg/ml, p < 0.001; IL-6, 3.2 +/- 0.2 pg/ml, p < 0.01; GM-CSF, 3.1 +/- 0.7 pg/ml, p < 0.001). Only in NYHA III-IV heart failure patients, plasma amylase levels were significantly correlated with plasma IL-6 activity (r = 0.86, p < 0.001), plasma norepinephrine levels (r = 0.82, p < 0.001) and right atrial pressure (r = 0.52, p < 0.05). Additionally, circulating IL-6 was also significantly correlated with plasma norepinephrine (r = 0.86, p < 0.001) and right atrial pressure (r = 0.57, p < 0.01). In conclusion, plasma amylase levels were elevated in severe heart failure patients and correlated well with circulating IL-6 activation, possibly as a result of both mesenteric venous congestion and impaired peripheral tissue perfusion observed in advanced chronic heart failure. However, the lack of association between plasma IL-6 and amylase levels in mild heart failure patients indicates an independent correlation of each variable with the functional status of the disease.

Gastrointestinal disorders of the critically ill. Bacterial translocation in the gut

The human gastrointestinal tract is colonized by a dense population of microorganisms, referred to as the bacterial flora. Although the gut provides a functional barrier between these organisms and the host, bacterial translocation is a common event in the healthy person. However, in critically ill patients, with various underlying diseases, this bacterial translocation may lead to infections and consequently to a further reduction in general health status. The mechanism of bacterial translocation is widely, and somehow controversially investigated in vitro and in animal models. In human studies, several diseases have been associated with bacterial translocation. However, methodological shortcomings, insufficient populations and conflicting results leave many open questions. This is also reflected in the various published therapeutic strategies. To overcome this problem more investigations in humans are needed, especially in techniques for detecting bacterial translocation.

Associations between circulating inflammatory markers and residual renal function in CRF patients

BACKGROUND

Circulating levels of cytokines and other inflammation markers are markedly elevated in patients with chronic renal failure. This could be caused by increased generation, decreased removal, or both. However, it is not well established to what extent renal function per se contributes to the uremic proinflammatory milieu. The aim of the present study is to analyze the relationship between inflammation and glomerular filtration rate (GFR) in 176 patients (age, 52 +/- 1 years; GFR, 6.5 +/- 0.1 mL/min) close to the initiation of renal replacement therapy.

METHODS

Circulating levels of high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), hyaluronan, and neopterin were measured after an overnight fast. Patients subsequently were subdivided into two groups according to median GFR (6.5 mL/min).

RESULTS

Despite the narrow range of GFR (1.8 to 16.5 mL/min), hsCRP, hyaluronan, and neopterin levels were significantly greater in the subgroup with lower GFRs, and significant negative correlations were noted between GFR and IL-6 (rho = -0.18; P < 0.05), hyaluronan (rho = -0.25; P < 0.001), and neopterin (rho = -0.32; P < 0.0005). In multivariate analysis, although age and GFR were associated with inflammation, cardiovascular disease and diabetes mellitus were not.

CONCLUSION

These results show that a low GFR per se is associated with an inflammatory state, suggesting impaired renal elimination of proinflammatory cytokines, increased generation of cytokines in uremia, or an adverse effect of inflammation on renal function.

Cardiovascular and renal sympathetic activation by blood-borne TNF-alpha in rat: the role of central prostaglandins

In pathophysiological conditions, increased blood-borne TNF-alpha induces a broad range of biological effects, including activation of the hypothalamic-pituitary-adrenal axis and sympathetic drive. In urethane-anesthetized adult Sprague-Dawley rats, we examined the mechanisms by which blood-borne TNF-alpha activates neurons in paraventricular nucleus (PVN) of hypothalamus and rostral ventrolateral medulla (RVLM), two critical brain regions regulating sympathetic drive in normal and pathophysiological conditions. TNF-alpha (0.5 microg/kg), administered intravenously or into ipsilateral carotid artery (ICA), activated PVN and RLVM neurons and increased sympathetic nerve activity, arterial pressure, and heart rate. Responses to intravenous TNF-alpha were not affected by vagotomy but were reduced by mid-collicular decerebration. Responses to ICA TNF-alpha were substantially reduced by injection of the cyclooxygenase inhibitor ketorolac (150 microg) into lateral ventricle. Injection of PGE(2) (50 ng) into lateral ventricle or directly into PVN increased PVN or RVLM activity, respectively, and sympathetic drive, with shorter onset latency than blood-borne TNF-alpha. These findings suggest that blood-borne cytokines stimulate cardiovascular and renal sympathetic responses via a prostaglandin-dependent mechanism operating at the hypothalamic level.

Why is coronary heart disease of uraemic patients so frequent and so devastating?

On September 6, 2001, Professor Fernando Valderrabano (Hospital Gregorio Marañon, Madrid) died at the age of 59 years. He was a leading figure in Spanish nephrology, a full professor of Medicine/Nephrology at the University Complutense of Madrid, and an outstanding scientist who published more than 300 articles in medical journals. He was a very intelligent and cultured person, and a man of great style who enjoyed a wide range of hobbies and interests in addition to his medical work. All his colleagues and friends mourn his passing.

Fluid status in CAPD patients is related to peritoneal transport and residual renal function: evidence from a longitudinal study

BACKGROUND

Both peritoneal transport characteristics as well as residual renal function are related to outcome in patients treated with continuous ambulatory peritoneal dialysis (CAPD). It has been suggested that part of this relationship might be explained by an effect of both parameters on the fluid state in CAPD patients or by the relationship between inflammation and peritoneal transport.

METHODS

In the present study, the relationship between fluid state [extracellular water (ECW) (sodium bromide); total body water (TBW) (deuterium oxide)] with peritoneal transport characteristics (2.27% glucose dialysate/plasma creatinine [D/P (creat)] ratio), residual renal function (residual glomerular filtration rate [rGFR] by urine collection) and C-reactive protein (CRP) was assessed in 37 CAPD patients in a cross-sectional and longitudinal design, with 25 patients completing the study.

RESULTS

In the cross-sectional part ECW, corrected for height (ECW:height), was inversely related to rGFR (r=-0.40, P=0.016), whereas during the longitudinal part, D/P[creat] was related to the change in ECW (r=0.40, P=0.05). Neither D/P[creat] nor rGFR were related to CRP, whereas a significant relationship was observed between ECW:height and CRP (r=0.58, P=0.0001). Patients were dichotomized according to rGFR (<2 or >2 ml/min). Despite a higher daily peritoneal glucose prescription (216.3+/-60.0 vs 156.5+/-53.0 g/24 h; P=0.004) and peritoneal ultrafiltration volume (1856+/-644 vs 658+/-781 ml/24 h, respectively; P=0.0001), the patients with a rGFR <2 ml/min showed a higher ECW:height compared with the group with rGFR >2 ml/min (12.5+/-3.8 vs 9.2+/-2.2 l/m, respectively; P=0.003). Results for TBW were comparable.

CONCLUSION

Fluid state was significantly related to peritoneal transport characteristics and rGFR. The larger ECW:height in CAPD patients with a negligible rGFR existed despite a higher peritoneal ultrafiltration volume and higher peritoneal glucose prescription. These findings raise doubts as to whether fluid state in CAPD patients with a diminished rGFR can be adequately controlled on standard glucose solutions without an additional sodium and fluid restriction. The preliminary finding of a relationship between CRP and fluid state might suggest a relationship between overhydration and inflammation.

Prognostic importance of weight loss in chronic heart failure and the effect of treatment with angiotensin-converting-enzyme inhibitors: an observational study

BACKGROUND

Weight loss in chronic heart failure is linked to impaired survival. We aimed to assess the frequency of weight loss in patients with this disease, whether the degree of weight loss predicts mortality, and whether weight loss can be prevented by angiotensin-converting-enzyme (ACE) inhibitors.

METHODS

We investigated weight changes in 1929 patients from the SOLVD trial who had chronic heart failure, were free of oedema at baseline, and survived for at least 4 months after trial entry. Meanfollow-up was 35 months (SD 13). We analysed the effect of weight loss at cutpoints of 5%, 7.5%, 10%, 15% (a priori), and 6% (post hoc) to identify which one best predicted outcome. To validate results, we analysed data for 619 patients in the V-HeFT II trial.

FINDINGS

817 (42%) patients in the SOLVD trial had weight loss from baseline of 5% or more. At 8 months follow-up, all cutpoints for weight loss were significantly associated with impaired survival after adjustment for age, sex, New York Heart Association class, left ventricular ejection fraction, and treatment allocation. Weight loss of 6% or more at any time during follow-up was the strongest predictor of impaired survival (adjusted hazard ratio 2.10, 95% CI 1.77-2.49; p<0.0001). Patients on the ACE inhibitor enalapril had a lower hazard of 6% or more weight loss than did those not taking the drug (adjusted reduction 19%, p=0.0054). Results from analyses of V-HeFT II data lent support to our findings.

INTERPRETATION

Weight loss occurs frequently in patients with chronic heart disease, its reversal is rare, and when present, it is independently linked to impaired survival. Weight loss of more than 6% should be used to define the presence of cachexia in patients with chronic heart failure. In chronic heart failure, treatment with an ACE inhibitor reduces the risk of weight loss.

LPS regulate ERK1/2-dependent signaling in cardiac fibroblasts via PKC-mediated MKP-1 induction

Activation of MAPK pathways by angiotensin II (Ang II) is important for cardiac fibroblast (CFB) proliferation and migration. Activity of MAP-kinases is closely controlled by a group of dual-specific MAP kinase phosphatases (MKPs). Lipopolysaccharides (LPS) and cytokines are elevated in patients with heart failure and may contribute to disease progression. In this study, we investigate the effect of LPS on Ang II-induced CFB function. Pretreatment of CFBs with LPS (1 microg/mL; 30 min) almost completely inhibited Ang II-induced DNA-synthesis and inhibited Ang II directed chemotaxis by more than 80%. Compared to controls, LPS pretreatment significantly reduced phosphorylation levels of ERK1/2- and p38 MAPK and induced MKP-1 levels. Silencing MKP-1 with antisense oligodesoxynucleotides reversed the antimitogenic effect of LPS on Ang II-induced CFB DNA-synthesis and migration. Induction of MKP-1 by LPS was inhibited by the protein kinase C (PKC)-inhibitor calphostin C, but not by the ERK1/2-pathway inhibitor PD98059, suggesting that PKC but not ERK1/2 is required for LPS-mediated MKP-1 induction in CFBs. Our data demonstrate that LPS have direct cellular effects in CFBs through an inhibition of Ang II-induced MAPK activity via PKC-mediated induction of MKP-1. This might be relevant with regard to the decreased MAPK activity and increased levels in MKPs reported during chronic heart failure in humans.

Immunomodulating therapy: new treatment modality in congestive heart failure

Accumulating evidence indicates that inflammatory cytokines play a pathogenic role in congestive heart failure (CHF) by influencing heart contractility, inducing hypertrophy, and promoting apoptosis or fibrosis, contributing to the continuous myocardial remodeling process. Traditional cardiovascular drugs seem to have little influence on the overall cytokine network, and immunomodulatory therapy has emerged as a possible new treatment modality in CHF. Several animal studies have suggested that modulation of inflammatory cytokines may improve cardiac performance. The authors have recently demonstrated that intravenous immunoglobulin enhances the left ventricular ejection fraction in CHF patients, and that this is significantly correlated with anti-inflammatory effects of such therapy. While intravenous immunoglobulin is not necessarily the drug of choice, this study suggests a potential role for immunomodulatory therapy in CHF in addition to optimal cardiovascular treatment regimens. Further research will more precisely identify the most important actors in the immunopathogenesis of CHF and contribute to the development of more specific immunomodulating agents for this disorder.

Nicotine inhibits cardiac apoptosis induced by lipopolysaccharide in rats

OBJECTIVES

Apoptosis develops in several heart diseases, but the therapeutic options are limited. It was hypothesized that nicotine, which inhibits apoptosis in several cells, inhibits cardiac apoptosis induced by lipopolysaccharide (LPS).

BACKGROUND

Over-the-counter nicotine produces sustained levels (10 to 25 ng/ml) that may be antiapoptotic. Low levels of LPS induce apoptosis by activating tissue renin-angiotensin to stimulate angiotensin II, type 1 (AT(1)) receptors in cardiac myocytes.

METHODS

Adult Sprague Dawley rats were pretreated with nicotine (6 mg/kg/day) or saline for seven to ten days (miniosmotic pumps). The LPS (1 mg/kg) was injected intravenously. Toll-like receptor 4 (TLR4) and angiotensinogen messenger ribonucleic acid (mRNA) were measured in the heart after 0, 4, 8, 16, and 24 h. Cardiac apoptosis was measured by terminal deoxy-nucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining after 24 h. In vitro effects of LPS (10 ng/ml, 24 h) were studied in cardiac myocytes isolated from rats pretreated with nicotine for 7 to 10 days, or after pre-exposing myocytes to nicotine (15 ng/ml) for 1, 4, 16, or 24 h.

RESULTS

Neither nicotine nor LPS affected systolic blood pressure. The LPS increased cardiac apoptosis after 24 h in saline-treated, but not nicotine-treated rats, despite similar increases in cardiac TLR4 and angiotensinogen mRNA over 8 to 16 h. The LPS-induced apoptosis was blocked by pre-exposing myocytes to nicotine for 4 to 24 h (partial inhibition after 1 h). Nicotine did not inhibit apoptosis induced by angiotensin II (100 nM, 24 h).

CONCLUSIONS

Therapeutic levels of nicotine inhibit LPS-induced cardiac apoptosis. This occurs after LPS increases TLR4 and angiotensinogen mRNA, but proximal to AT(1) receptor activation. Nicotine may be a novel inhibitor of cardiac apoptosis in conditions associated with circulating LPS (e.g., decompensated heart failure, acute and chronic infections).

Therapeutic inhibition of tumour necrosis factor alpha in patients with heart failure: cooling an inflamed heart

Heart failure is a systemic disorder characterised by tissue hypoxia and secondary organ dysfunction which occurs in response to various myocardial insults that include ischaemia, viral infections, and toxins. In addition to maladaptive neurohumoral activation, heart failure is associated with an inflammatory state that appears to have a detrimental effect on cardiac function and prognosis. This has led to the suggestion that anti-inflammatory interventions may have therapeutic potential in the symptomatic and prognostic treatment of patients with heart failure. This review considers the role of inhibition of the cytokine tumour necrosis factor alpha in the treatment of heart failure.

Increased lipopolysaccharide binding protein in cirrhotic patients with marked immune and hemodynamic derangement

Intestinal bacterial overgrowth and translocation, both common in cirrhosis with ascites, may lead to the activation of monocytes and lymphocytes, increased levels of proinflammatory cytokines, and enhanced synthesis of nitric oxide present in cirrhosis. Bacterial endotoxin promotes the synthesis of lipopolysaccharide (LPS)-binding protein (LBP), and forms a LPS-LBP complex that binds to CD14. This study was designed to evaluate LBP levels and their correlation to the immune response and the hemodynamic status in cirrhotic patients. Plasma LBP, endotoxin, soluble CD14 (sCD14), cytokines, renin, nitrites, and systemic vascular resistance were determined before and 4 weeks after norfloxacin or placebo in 102 cirrhotic patients and 30 controls. LBP was elevated in 42% of ascitic cirrhotic patients (15.7 +/- 0.7 versus 6.06 +/- 0.5 microg/mL, P <.01). In 60% of high LBP patients, endotoxin was within normal range. Among ascitic patients, those with high LBP showed greater (P <.05) levels of sCD14, tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), nitrites + nitrates (NOx)/creatinine, and renin, and lower vascular resistance. In the cirrhotic patients with high LBP, norfloxacin normalized (P <.01) LBP (from 16.6 +/- 0.5 to 5.82 +/- 0.8 microg/mL) and sCD14; reduced the level of cytokines, NOx/creatinine, and renin; and increased vascular resistance; but lacked effect in patients with normal LBP. Portal pressure was unchanged after norfloxacin in another group of 18 cirrhotic patients with high and 19 with normal LBP. In conclusion, the subset of ascitic cirrhotic patients with marked immune and hemodynamic derangement is identified by increased LBP levels. Amelioration of these abnormalities by norfloxacin suggests the involvement of enteric bacteria or their products in the triggering of the process.

Statins and the role of nitric oxide in chronic heart failure

Endothelial dysfunction plays an important role in a number of cardiovascular diseases. An important pathogenetic factor for the development of endothelial dysfunction is lack of nitric oxide (NO), which is a potent endothelium-derived vasodilating substance. 3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins), originally designed to lower plasma cholesterol levels, seem to ameliorate endothelial dysfunction by a mechanism so far only partly understood. However, statins increase nitric oxide synthase activity. It has been speculated that this and other "side effects" of statin treatment are due to inhibition of Rho, an intracellular signalling protein that initiates Rho kinase transcription. Moreover, statins possess anti-inflammatory characteristics. Some statins have proven to lower plasma levels of C-reactive protein, which is induced by pro-inflammatory cytokines. Other statins have been demonstrated to directly inhibit pro-inflammatory cytokine induction. Finally, some data suggest that statins might be able to counterbalance an increased production of oxygen free radicals. Since chronic heart failure is accompanied not only by endothelial dysfunction, but also by pro-inflammatory cytokine activation and enhanced formation of oxygen free radicals, it is tempting to speculate that statins might be an ideal candidate to treat certain features of this disease. The doses needed to achieve the desired effects might be much lower than those needed to treat hypercholesterolemia.

Pathophysiologic quantities of endotoxin-induced tumor necrosis factor-alpha release in whole blood from patients with chronic heart failure

Bacterial endotoxin activity is elevated in patients with decompensated chronic heart failure (HF) and acts as a potent stimulus for immune activation. We sought to determine whether endotoxin, at an activity level seen in vivo (around 0.6 EU/ml), is sufficient to stimulate the secretion of tumor necrosis factor-alpha (TNF-alpha) and TNF-alpha soluble receptor (sTNFR2) in ex vivo whole blood from patients with HF. We studied 15 patients with HF (aged 65 +/- 1.9 years, New York Heart Association class 2.1 +/- 0.3, left ventricular ejection fraction 31 +/- 5%; mean +/- SEM), of whom 5 had cardiac cachexia, and 7 healthy control subjects (59 +/- 5 years, p = NS). Reference endotoxin was added to venous blood at concentrations of 0.6, 1.0, and 3.0 EU/ml, and was incubated for 6 hours. Endotoxin induced a dose-dependent increase in TNF-alpha release (p <0.05 in all groups). Patients with noncachectic HF produced significantly more TNF-alpha compared with controls after stimulation with 0.6, 1.0, and 3.0 EU/ml of endotoxin (113 +/- 46 vs 22 +/- 4 [p = 0.009], 149 +/- 48 vs 34 +/- 4 [p = 0.002], and 328 +/- 88 vs 89 +/- 16 pg/ml [p = 0.002], respectively; mean +/- SEM). Patients with cardiac cachexia produced significantly less TNF-alpha compared with patients without cardiac cachexia for all given concentrations (all p <0.05, analysis of variance p = 0.02). Production of sTNFR2 was greater at all concentrations of endotoxin versus controls (all p <0.05, analysis of variance p = 0.002). Plasma endotoxin levels were higher in patients with cardiac cachexia (4.3 times higher than in control subjects, p <0.005). Thus, low endotoxin activity, at levels seen in vivo in patients with HF, induces significant TNF-alpha and sTNFR2 production ex vivo. These results suggest that elevated plasma endotoxin activity observed in patients with HF is of pathophysiologic relevance.

Chronic heart failure and the immune system

Several lines of evidence support a role of immune mechanisms in the pathogenesis of chronic heart failure (CHF). Proinflammatory cytokines (interleukin-1, -2, -6, and tumor necrosis factor) and chemokines are involved in cardiac depression and in the progression of heart failure. Other components believed to be relevant to the pathogenesis of CHF are adhesion molecules, autoantibodies, nitric oxide (NO), and endothelin-1. The origin of the immune activation in patients with CHF is still unknown, however two hypotheses have been proposed on the basis of experimental and clinical data. One suggests that the bowel wall edema leads to bacterial translocation with subsequent endotoxin release and immune activation. The second suggests that the heart in CHF is the main source of cytokines, as is shown by the fact that TNF alpha is produced by the failing myocardium but not by a normal one. No single source of cytokine production (gut or heart) seems sufficient to fully explain the multiple organ involvement and the systemic inflammation of CHF, which is probably related to systemic hypoxia, a potent stimulus for activation of the immune system and for cytokine production. The effort of define the immune system's role has opened new perspectives of therapeutic strategies, such as anti-cytokine drugs, to treat CHF.

Inflammatory signals associated with hemodialysis

BACKGROUND

Inflammation is highly prevalent in chronic hemodialysis patients. Because hemodialysis involves the contact of blood with "foreign" surfaces, and the documented activation of several humoral and cellular pathways during the procedure, the hemodialysis procedure has been suggested as a potential source of inflammation in this patient population. Earlier studies did not provide clear-cut evidence of the potential contribution of the hemodialysis procedure to inflammation, as assessed by markers of inflammation such as cytokine levels and acute-phase protein production.

METHODS

Nine patients were studied using primed-constant infusion of l-(l-13C) leucine 2 hours before, during, and 2 hours after a single hemodialysis session. We evaluated the effects of hemodialysis on induction of interleukin-6 (IL-6) production as well as the fractional synthetic rates (FSR) of albumin and fibrinogen, two well-known acute-phase proteins.

RESULTS

During hemodialysis, albumin FSR and fibrinogen FSR increased significantly compared to the measurements obtained during baseline period. During this period, albumin and fibrinogen FSR increased 64% and 34%, respectively, compared to baseline (P < 0.05). While the increase in IL-6 concentration was modest during hemodialysis (14%), the levels further increased at the end of the 2-hour post-hemodialysis period (68% higher compared to baseline, P < 0.05). Fibrinogen FSR also demonstrated a further increase during the post-dialysis period (17% higher compared to the intradialytic period and 58% higher compared to baseline), while albumin FSR stabilized during this period.

CONCLUSIONS

The results provide clear evidence of hemodialysis-induced inflammatory response. The process is most notable during the 2-hour post-hemodialysis period.

Neurohormonal factors in the development of catabolic/anabolic imbalance and cachexia

Mechanisms that lead to cachexia are still poorly understood. The neurohormonal changes that occur in severe disease states may cause an imbalance between protein synthesis and degradation at the cellular level, followed by muscle wasting. Here, we review actions of angiotensin II, TNF-alpha, corticosteroids, insulin-like growth factor-I (IGF-I), and the IGF binding proteins, factors that may each contribute to the metabolic imbalance. The complex endocrine, autocrine and intracellular interactions between these factors will be described with examples from patient, rat and cell culture studies. Moreover, some of the data supporting that each of these hormones may directly affect cellular protein degradation mechanisms will be reviewed. Knowledge on these regulatory mechanisms will facilitate the development of new pharmaceutical strategies to treat cachexia.

The syndrome of cardiac cachexia

Cachexia, i.e. body wasting, has long been recognised as a serious complication of chronic illness. The occurrence of wasting in chronic heart failure (CHF) has been known for many centuries, but it has not been investigated extensively until recently. Cardiac cachexia is a common complication of CHF which is associated with poor prognosis, independently of functional disease severity, age, measures of exercise capacity, and left ventricular ejection fraction. Patients with cardiac cachexia suffer from generalised loss of lean tissue, fat tissue, as well as bone tissue. Cachectic CHF patients are weaker and fatigue earlier. This is due to both reduced skeletal muscle mass and impaired skeletal muscle quality. Concerning the pathophysiology of cardiac cachexia, there is increasing evidence that neurohormonal and immune abnormalities may play a crucial role. Cachectic CHF patients have raised plasma levels of norepinephrine, epinephrine, and cortisol, and they show high plasma renin activity and increased plasma aldosterone levels. A number of studies have also shown that cardiac cachexia is linked to raised plasma levels of inflammatory cytokines, such as tumor necrosis factor alpha. The available evidence suggests that cardiac cachexia is a multifactorial neuroendocrine and metabolic disorder with a poor prognosis. A complex imbalance of different body systems, termed catabolic/anabolic imbalance, is likely to be responsible for the development of the wasting process. It is hoped that a better understanding of the pathophysiological mechanisms involved in cardiac cachexia will lead to novel therapeutic strategies in the (near) future.

Chronic heart failure: an example of a systemic chronic inflammatory disease resulting in cachexia

Chronic heart failure is no longer a mere cardiac entity, but involves several, initially adaptive and later detrimental, neurohumoral compensatory mechanisms. Peripheral manifestations of the disease, such as endothelial dysfunction, skeletal muscle changes, and disturbances in ventilatory control, are major determinants of symptoms. The independent prognostic value and the relevance of cachexia on morbidity of patients with chronic heart failure have only recently been recognised. Altered body composition in heart failure patients is reflected in the early loss of muscle tissue but affects all tissue compartments in case of cardiac cachexia. Recently, a new portfolio of biologically active molecules, termed cytokines, have been shown to play an important role in the development and progression of both cardiac and peripheral abnormalities. Similar to other chronic illnesses, covered in the remainder of this issue, a low-grade chronic inflammatory process may be of particular relevance in the development of tissue wasting in these patients. Whereas the presence of immune activation in chronic heart failure is now widely accepted, as well as the prognostic relevance of chronic inflammation, the site and the source of cytokine production remain the object of intense research. Although the inciting event is located in the heart, cross-talk between the myocardium on the one hand, and the immune system, peripheral tissues and organs on the other hand, will lead to the overproduction of proinflammatory cytokines and, inevitably, to their detrimental effects. The specific problems related to heart failure progression and inflammatory activation are described in this review.