Tumour necrosis factor alpha as a predictor of impaired peak leg blood flow in patients with chronic heart failure

Vascular Function in Continuous Flow LVADs: Implications for Clinical Practice

Left ventricular assist devices (LVADs) have been increasingly used in patients with advanced heart failure, either as a destination therapy or as a bridge to heart transplant. Continuous flow (CF) LVADs have revolutionized advanced heart failure treatment. However, significant vascular pathology and complications have been linked to their use. While the newer CF-LVAD generations have led to a reduction in some vascular complications such as stroke, no major improvement was noticed in the rate of other vascular complications such as gastrointestinal bleeding. This review attempts to provide a comprehensive summary of the effects of CF-LVAD on vasculature, including pathophysiology, clinical implications, and future directions.

Inflammation, dysregulated iron metabolism, and cardiovascular disease

Iron is an essential trace element associated with both pathologic deficiency and toxic overload. Thus, systemic and cell iron metabolism are highly controlled processes regulated by protein expression and localization, as well as turnover, through the action of cytokines and iron status. Iron metabolism in the heart is challenging because both iron overload and deficiency are associated with cardiac disease. Also associated with cardiovascular disease is inflammation, as many cardiac diseases are caused by or include an inflammatory component. In addition, iron metabolism and inflammation are closely linked. Hepcidin, the master regulator of systemic iron metabolism, is induced by the cytokine IL-6 and as such is among the acute phase proteins secreted by the liver as part of the inflammatory response. In an inflammatory state, systemic iron homeostasis is dysregulated, commonly resulting in hypoferremia, or low serum iron. Less well characterized is cardiac iron metabolism in general, and even less is known about how inflammation impacts heart iron handling. This review highlights what is known with respect to iron metabolism in the heart. Expression of iron metabolism-related proteins and processes of iron uptake and efflux in these cell types are outlined. Evidence for the strong co-morbid relationship between inflammation and cardiac disease is also reviewed. Known connections between inflammatory processes and iron metabolism in the heart are discussed with the goal of linking inflammation and iron metabolism in this tissue, a connection that has been relatively under-appreciated as a component of heart function in an inflammatory state. Therapeutic options connecting inflammation and iron balance are emphasized, with the main goal of this review being to bring attention to alterations in iron balance as a component of inflammatory diseases of the cardiovascular system.

Inflammatory Response to Acute Myocardial Infarction Complicated by Cardiogenic Shock

We report a case of a 60-year-old man with acute myocardial infarction (AMI) treated using thrombolysis, and complicated by cardiogenic shock (CS). Plasma interleukin (IL) 1β, IL 6, IL 8, tumor necrosis factor alpha (TNFα), and soluble adhesion molecule (sICAM 1, sE-selectin) levels were measured at 3-h intervals. This observation showed the effect of AMI and CS on the plasma interleukin levels. Remarkable changes were found in the plasma TNF α level, which reached two significant peaks. The peak of the first elevation caused by AMI (80.11 pg/ml, vs. normal value 4.35 pg/ml, SD 21.3 pg/ml) was seen 6 h after the onset of the symptoms. After the period of significant decrease, TNF α level was increasing until the end of the observation period because of CS (the last TNF α level was 204.1 pg/ml). The plasma IL 1β level was continually increased during the period of observation (maximal IL 1β level 32.1 pg/ml, normal value <10 pg/ml). The plasma IL 6 level reached the first peak caused by AMI nine hours after the onset of the symptoms (362.85 pg/ml, normal value (10 pg/ml). Because of CS, after the short period of decrease, the plasma IL 6 level was increasing until the end of the observation period (the last IL 6 level was 859.61 pg/ml). The plasma IL 8 level was also elevated throughout the time of observation (max. value 1652 pg/ml, vs. normal value <30pg/ml). The soluble adhesion molecule levels (sE-selectin and sICAM 1) were elevated throughout the period of observation without any significant peak.

Markers of inflammation in recipients of continuous-flow left ventricular assist devices

Although the newer continuous-flow left ventricular assist devices (CF-LVADs) provide clinical advantages over the pulsatile pumps, the effects of low pulsatility on inflammation are incompletely understood. The objective of our study was to examine the levels of inflammatory mediators in CF-LVAD recipients compared with both healthy control subjects and heart failure patients who were candidates for CF-LVAD support. Plasma levels of chemokines, cytokines, and inflammatory markers were measured in 18 CF-LVAD recipients and compared with those of 14 healthy control subjects and 14 heart failure patients who were candidates for CF-LVADs. The levels of granulocyte macrophage-colony stimulating factor, macrophage inflammatory proteins-1β, and macrophage-derived chemokine were significantly higher in the CF-LVAD group compared with both the heart failure and the healthy control groups, whereas no significant differences were observed between the healthy control subjects and the heart failure groups. Compared with the healthy controls, C-reactive protein, interferon gamma-induced protein-10, monocyte chemotactic protein-1, and interleukin-8 levels were significantly higher in both the CF-LVAD and heart failure groups, but no significant differences were observed between the CF-LVAD recipients and the heart failure patients. Inflammatory markers were elevated in CF-LVAD recipients compared with healthy control subjects and the heart failure patients. Further studies should investigate the clinical implications of elevated levels of inflammation in CF-LVAD recipients.

Longitudinal assessment of inflammation in recipients of continuous-flow left ventricular assist devices

BACKGROUND

The long-term effects of continuous-flow left ventricular assist device (CF-LVAD) support on trends of inflammatory markers over time are unknown. We examined the hypothesis that the levels of inflammatory markers in CF-LVAD recipients are higher than in healthy controls and that these levels increase over time with long-term CF-LVAD support.

METHODS

We examined the levels of inflammatory markers longitudinally at baseline before CF-LVAD implantation and at 3, 6, and 9 months after implantation. We then compared the levels of inflammatory markers to those in a healthy control group.

RESULTS

Compared with baseline values before CF-LVAD implantation, left ventricular end-diastolic diameter (LVEDd) and left ventricular end-systolic diameter (LVESd) decreased significantly at 3, 6, and 9 months after CF-LVAD implantation. Brain natriuretic peptide (BNP) levels dropped significantly after CF-LVAD implantation but did not normalize. Improvements in ejection fraction at 3, 6, and 9 months after CF-LVAD implantation did not reach significance. Monocyte chemoattractant protein-1, interferon γ-induced protein, and C-reactive protein levels were higher in the CF-LVAD recipients at each of the time points (baseline before CF-LVAD implantation and 3, 6, and 9 months after implantation) compared with levels in healthy controls. In CF-LVAD recipients, serum interleukin-8, tumour necrosis factor-α, and macrophage inflammatory protein-β increased significantly at 9 months, and macrophage-derived chemokine increased at 6 months after CF-LVAD implantation compared with baseline.

CONCLUSIONS

Despite improvements in LV dimensions and BNP levels, markers of inflammation remained higher in CF-LVAD recipients. High levels of inflammation in CF-LVAD recipients may result from heart failure preconditioning or the long-term device support, or both. Because inflammation may be detrimental to CF-LVAD recipients, future studies should determine whether inflammatory pathways are reversible.

Ursodeoxycholic acid in patients with chronic heart failure: a double-blind, randomized, placebo-controlled, crossover trial

OBJECTIVES

This study sought to assess the effects of ursodeoxycholic acid (UDCA) on endothelial function and inflammatory markers in patients with chronic heart failure (CHF).

BACKGROUND

Endothelial dysfunction is commonly observed in patients with CHF, and it contributes to the limitation in exercise capacity that accompanies this condition. Bacterial lipopolysaccharide may trigger proinflammatory cytokine release and promote further endothelial dysfunction. UDCA, a bile acid used in the treatment of cholestatic liver disease, has anti-inflammatory and cytoprotective properties and may contribute to the formation of mixed micelles around lipopolysaccharide. These properties may help to improve peripheral blood flow in patients with CHF.

METHODS

We performed a prospective, single-center, double-blind, randomized, placebo-controlled crossover study of UDCA in 17 clinically stable male patients with CHF (New York Heart Association functional class II/III, left ventricular ejection fraction <45%). Patients received in random order 500 mg UDCA twice daily for 4 weeks and placebo for another 4 weeks. The primary endpoint was post-ischemic peak peripheral arm blood flow as assessed by strain-gauge plethysmography.

RESULTS

Sixteen patients completed the study. UDCA was well tolerated in all patients. Compared with placebo, UDCA improved peak post-ischemic blood flow in the arm (+18%, p = 0.038), and a trend for improved peak post-ischemic blood flow in the leg was found (+17%, p = 0.079). Liver function improved: compared with placebo, levels of γ-glutamyl transferase, aspartate transaminase, and soluble tumor necrosis factor α receptor 1 were lower after treatment with UDCA than after placebo (all p < 0.05). There was no change in 6-min walk test or New York Heart Association functional class, and levels of tumor necrosis factor α and interleukin-6 were unchanged or increased compared with placebo.

CONCLUSIONS

UDCA is well tolerated in patients with CHF. UDCA improves peripheral blood flow and is associated with improved markers of liver function.

Cardio-renal cachexia syndromes (CRCS): pathophysiological foundations of a vicious pathological circle

Cardio-renal syndromes (CRS) are defined as disorders of the heart and kidney whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction of the other. CRS have been classified into five categories, where types 2 and 4 represent respectively chronic cardio-renal and chronic reno-cardiac syndromes. In these conditions, the chronic disorder of either the heart or kidney has been shown to induce some degree of cachexia. At the same time, cachexia has been proposed as a possible mechanism contributing to the worsening of such pathological organ cross talk. Common pathogenetic mechanisms underlie body wasting in cachectic states of different chronic heart and kidney diseases. In these circumstances, a vicious circle could arise, in which cachexia associated with either heart failure or chronic kidney disease may contribute to further damage of the other organ. In chronic CRS, activation of the immune and neuroendocrine systems contributes to the genesis of cachexia, which in turn can negatively affect the heart and kidney function. In patients with cardiac sustained activation of the immune and neuroendocrine systems and oxidative stress, renal vascular resistance can increase and therefore impair renal perfusion, leading to worsening kidney function. Similarly, in renal cachexia, increased levels of pro-inflammatory cytokines can cause progressive left ventricular systolic dysfunction, myocardial cell death, endothelial dysfunction and increased myocardial fibrosis, with consequent impairment of the chronic reno-cardiac syndrome type 4. Thus, we speculate that the occurrence of different types of chronic CRS could represent a fundamental step in the genesis of cachexia, being renal and cardiac dysfunction closely related to the occurrence of systemic disorders leading to a final common pathway. Therefore, the heart and kidney and cachexia represent a triad causing a vicious circle that increases mortality and morbidity: In such circumstances, we may plausibly talk about cardio-renal cachexia syndrome. Complex interrelations may explain the transition from CRS to cachexia and from cachexia to CRS. Identification of the exact mechanisms occurring in these conditions could potentially help in preventing and treating this deadly combination.

Treatment with iron of patients with heart failure with and without anemia

Iron deficiency is a common cause of anemia in otherwise healthy individuals and plays an important role in the development of anemia within the heart failure patient population. Iron-deficient heart failure patients experience worse symptoms and are less exercise tolerant than those without iron deficiency. These symptoms may occur even before clinical anemia is evident. This article reviews studies of the benefits of the use of intravenous iron to treat iron deficiency in anemic and nonanemic heart failure patients and an overview of the physiology and pathophysiology of iron metabolism in chronic heart failure.

Dose-dependent effects of omega-3-polyunsaturated fatty acids on systolic left ventricular function, endothelial function, and markers of inflammation in chronic heart failure of nonischemic origin: a double-blind, placebo-controlled, 3-arm study

BACKGROUND

Supplementation with 1 g/d omega-3-polyunsaturated fatty acids (n3-PUFAs) demonstrated a small survival advantage in patients with chronic heart failure (CHF) in the GISSI-HF trial. However, a dose-efficacy relationship was postulated for the beneficial effects of n3-PUFA before. Therefore, we evaluated dose-dependent effects of n3-PUFA in patients with severe CHF.

METHODS

In a double-blind, randomized, controlled pilot trial, 43 patients with severe, nonischemic heart failure received 1 g/d n3-PUFA (n = 14), 4 g/d n3-PUFA (n = 13), or placebo (n = 16) for 3 months. Changes in left ventricular ejection fraction (LVEF), flow-mediated vasodilation, plasma high-sensitive interleukin 6 and high-sensitive tumor necrosis factor α, and exercise peak oxygen consumption were assessed.

RESULTS

Left ventricular ejection fraction increased in a dose-dependent manner (P = .01 for linear trend) in the 4 (baseline vs 3 months [mean ± SD]: 24% ± 7% vs 29% ± 8%, P = .005) and 1 g/d treatment groups (24% ± 8% vs 27% ± 8%, P = .02). Flow-mediated vasodilation increased significantly with high-dose 4 g/d n3-PUFA (8.4% ± 4.8% vs 11.6% ± 7.0%, P = .01) but only trendwise with low-dose 1 g/d (8.3% ± 5.3% vs 10.2% ± 4.3%, P = .07). Interleukin 6 significantly decreased with 4 g/d n3-PUFA (3.0 ± 2.9 pg/mL vs 0.7 ± 0.8 pg/mL, P = .03) but only trendwise with 1 g/d (4.5 ± 6.6 pg/mL to 1.6 ± 2.1 pg/mL, P = .1). High-sensitive tumor necrosis factor α decreased trendwise with 4 g/d n3-PUFA but remained unchanged with 1 g/d. In patients with maximal exercise effort, only 4 g/d increased the peak oxygen consumption. No changes in any investigated parameters were noted with placebo.

CONCLUSION

Treatment with n3-PUFA for 3 months exerts a dose-dependent increase of LVEF in patients with CHF. In parallel, a significant improvement of endothelial function and decrease of interleukin 6 is found with high-dose n3-PUFA intervention.

The effects of a high-caloric protein-rich oral nutritional supplement in patients with chronic heart failure and cachexia on quality of life, body composition, and inflammation markers: a randomized, double-blind pilot study

The prevalence of cardiac cachexia in chronic heart failure is approximately 5% to 15% and 18-month mortality rates can reach 50%. Treatment with angiotensin-converting enzyme inhibitors and beta-blockers may confer some benefit but no proven therapy exists. We tested the effects of an oral nutritional supplement in cachectic patients with heart failure. This was a prospective, randomized, double-blind, placebo-controlled pilot study which randomized 29 patients to a high-caloric (600 kcal) high-protein (20 g) oral nutritional supplement or placebo for a duration of 6 weeks in addition to the patients' usual food intake. At baseline, 6 weeks, and 18 weeks, we measured body weight, quality of life, body composition, heart function, laboratory parameters, and exercise performance. Edema-free body weight increased in 19 of 20 patients receiving intervention at 6 weeks and in 17 of 19 patients at 18 weeks with an average weight gain of 2.0 ± 1.7 kg (3.1 ± 2.4%, p = 0.0001) and 2.3 ± 3.1 kg (3.6 ± 4.7%, p = 0.007) at 6 and 18 weeks, respectively. Most of the weight gain was fat tissue with an absolute gain of 1.5 ± 1.7 kg (p = 0.003) and 1.6 ± 2.7 kg (p = 0.008). A significant improvement in quality of life and decrease in serum levels of tumor necrosis factor-α were observed (p < 0.05 for both). We demonstrated the feasibility of oral nutritional supplement in cachectic patients with heart failure and significant clinical benefit in terms of body size and body composition, laboratory parameters, and quality of life (www.clinicaltrials.gov identifier NCT00654719).

Sphingomyelinases: their regulation and roles in cardiovascular pathophysiology

Sphingomyelinases (SMases) hydrolyse sphingomyelin, releasing ceramide and creating a cascade of bioactive lipids. These lipids include sphingosine and sphingosine-1-phosphate, all of which have a specific signalling capacity. Sphingomyelinase activation occurs in different cardiovascular system cell types, namely cardiac myocytes, endothelial and vascular smooth muscle cells, mediating cell proliferation, cell death, and contraction of cardiac and vascular myocytes. Three main types of SMases contribute to cardiovascular physiology: the lysosomal and secreted acidic SMases (L- and S-ASMases, respectively) and the membrane neutral SMase (NSMase). These three enzymes have common activators, including ischaemia/reperfusion stress and proinflammatory cytokines, but they differ in their enzymatic properties and subcellular locations that determine the final effect of enzyme activation. This review focuses on the recent advances in the understanding of ASMase and NSMase pathways and their specific contribution to cardiovascular pathophysiology. Current knowledge indicates that the inhibitors of the different SMase types are potential tools for the treatment of cardiovascular diseases. Acid SMase inhibitors could be tools against post-ischaemia reperfusion injury and in the treatment of atherosclerosis. Neutral SMase inhibitors could be tools for the treatment of atherosclerosis, heart failure, and age-related decline in vasomotion. However, the design of bioavailable and more specific SMase-type inhibitors remains a challenge.

PKC and MLCK-dependent, cytokine-induced rat coronary endothelial dysfunction

BACKGROUND

Heart disease is one of the leading causes of death in the United States, killing nearly one million people every year. Inflammatory mediators or cytokines are released following myocardial infarction and ischemia/reperfusion injury. These cytokines, of which interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha (TNF-alpha) are among the most important, propagate the activation of a multitude of signaling pathways, such as the protein kinase C (PKC) and myosin light chain kinase (MLCK) pathways, which lead to deleterious changes in the structure and function of the coronary microvascular endothelium.

METHODS

The effects of cytokines on rat heart microvascular endothelial cell monolayer integrity, PKC activity, and adherens junction protein alteration were examined. Further, an in vivo rat coronary ischemia/reperfusion injury model was used to determine vascular leakage and TNF-alpha release.

RESULTS

Administration of the above mentioned cytokines to cell monolayers resulted in significant increases in PKC activation, gap formation, and hyperpermeability across the monolayer and beta-catenin phosphorylation/reorganization. Inhibition of conventional PKC and MLCK attenuated permeability increases. Ischemia/reperfusion injury to the left ventricle resulted in TNF-alpha release as well as conventional PKC- and MLCK-dependent protein extravasation from the circulation to the heart tissue.

CONCLUSION

These results identify the conventional PKC and MLCK pathways as important factors in coronary endothelial dysfunction elicited by IR injury and cytokine release. Further examination of these molecular signaling cascades has the potential of identifying targets for therapeutic intervention following ischemic events in the heart.

Effects of statins beyond lipid lowering: Potential for clinical benefits

BACKGROUND

The role of statin drugs in the reduction of serum lipids has been well documented. More recently, evidence suggesting that statins may positively impact many organ systems and disease states independent of lipid reduction has emerged. The term "pleiotropic effects" has been used to refer to these properties. We reviewed the evidence exploring such potential effects.

METHODS

A search of the MEDLINE database was conducted for articles published between 1985 to 2005 on the pleiotropic and the lipid-lowering independent effects of statin drugs. The search terms "statin", "HMG-CoA reductase inhibitor", "pleiotropic effects", and "inflammation" were used. English language articles were selected for inclusion along with selected cross-references.

RESULTS

Numerous animal and clinical studies support the presence of a spectrum of beneficial effects for statins that are independent of their lipid-lowering properties. These effects are mediated by a variety of mechanisms and they suggest that the therapeutic role of statins may expand.

CONCLUSION

Statins have shown great promise beyond their lipid-lowering effects. Ongoing and future studies will help to further clarify the potential clinical impact of these "pleiotropic effects".

Tumor necrosis factor-alpha, biologic agents and cardiovascular risk

The increased risk of premature cardiovascular disease (CVD) in rheumatoid arthritis (RA) patients may depend on traditional risk factors but may also be attributable to RA-specific risk factors such as disease-related dyslipidemia, or cytokines such as tumor necrosis factor-alpha (TNF-alpha). TNF-alpha is a proinflammatory cytokine that can produce widespread deleterious effects when expressed in large amounts. It is produced in the heart by both cardiac myocytes and resident macrophages under conditions of cardiac stress, and is thought to be responsible for many of the untoward manifestations of cardiac disease. TNF-alpha may play a role in the triggering and perpetuation of atherosclerosis. Treatment with biologic agents directed against TNF-alpha has significant clinical benefits in inflammatory diseases such as RA and may be able to reduce cardiovascular risk. The disappointing results of the recent studies to antagonize TNF-alpha in CVD may have various explanations. However, the effects of TNF-alpha blockers on incident cases of congestive heart failure (CHF) in RA remains controversial. Due to the lack of evidence of a beneficial effect of anti-TNF-alpha agents in treatment of CHF, they should not be used to treat patients with New York Heart Association (NYHA) class III or IV heart failure.

The roles of immunity and autoimmunity in chronic heart failure

Chronic heart failure (CHF) represents a major public health burden in developed countries. The introduction of new treatments has helped to improve its prognosis in recent years. However, it is still not possible to directly target the immunological aspects of the disease. In fact, chronic immune activation with the up-regulation of pro-inflammatory substances in the plasma remains an important feature of the disease, independently of its aetiology. Autoimmune mechanisms play a significant role in a subgroup of patients with dilated cardiomyopathy. The interplay between the two systems has not been established so far. This review briefly summarizes immune and autoimmune mechanisms in CHF.

Uric acid in chronic heart failure

The pathophysiologic understanding of chronic heart failure (CHF) has shifted from a mere hemodynamic disorder to a much more complex approach including changes and imbalances in neurohormonal, immune, and metabolic functions. Among metabolic abnormalities, hyperuricemia is a constant finding in CHF. The xanthine oxidase metabolic pathway increasingly is appreciated as an important contributor to both symptoms of CHF as well as progression of the disease. Recent data suggest hyperuricemia to be an independent marker of impaired prognosis in CHF. In this article, the significance of the xanthine oxidase metabolic pathway in CHF is discussed. Data on xanthine oxidase inhibition are reviewed, which suggest a beneficial effect of therapeutically targeting this enzymatic pathway.

Restrictive filling pattern is associated with increased humoral activation and impaired exercise capacity in dilated cardiomyopathy

OBJECTIVES

Although heart failure (HF) is characterized by increased proinflammatory cytokines, natriuretic peptide levels and impaired exercise capacity, the effect of concomitant diastolic dysfunction on those parameters has not been adequately studied.

METHODS

We analyzed circulating levels of IL-1, IL-6, TNF-alpha and its soluble receptors, sTNFRI and sTNFRII, Nt-ANP and Nt-BNP natriuretic peptides in 81 patients, aged 56+/-12 years, with non-ischemic dilated cardiomyopathy (NIDC), LVEF 29.7+/-7.75% and functional NYHA class II-III. An echocardiographic study and cardiopulmonary exercise test (CPE) were performed in all patients.

RESULTS

Patients were divided into restrictive (24 patients, group I) and non-restrictive (57 patients, group II) groups, according to their transmitral-filling pattern. No differences in LV dimensions or LVEF were found between the two groups. Group I showed increased levels of IL-6 (P=0.006), TNF-alpha (P=0.05), sTNFRII (P=0.02), Nt-ANP (P<0.001) and Nt-BNP (P<0.001) and decreased exercise duration (P<0.001) and PVO(2) (P<0.001) compared to group II. The strongest independent predictors for restrictive filling pattern were Nt-ANP and IL-6 levels, while Nt-BNP levels were the strongest PVO(2) predictor.

CONCLUSIONS

Restrictive filling pattern implying greater diastolic dysfunction may contribute to increased cytokine production in the heart failure syndrome, as well as greater increases in natriuretic peptides and decreased exercise tolerance.

Exercise and aging

There is increasing evidence that the black box we have referred to as"biologic aging" is composed of genetic factors and many types of environmental exposures. Some of the most potentially modifiable elements of this syndrome are those attributable to disuse or insufficient exposure to certain kinds or intensities of physical stressors during the course of the life span. Beneficial adaptations to exercise once thought restricted to genetically endowed master athletes now are seen to occur just as predictably in frail elders with chronic disease, opening the door to vastly improved physical function and associated health benefits. Knowledge of the benefits of physical activity, however well substantiated, may be necessary, but it is not sufficient to change either physician-prescribing habits or the likelihood of adoption and long-term adherence to exercise on the part of patients. Ultimately, the penetration of an exercise prescription to optimize aging into the most inactive cohorts in the community,who have the most to gain from increases in levels of physical activity and fitness, will depend on a combination of clear evidence-based guidelines coupled with health professional training and behavioral programs tailored to age-specific barriers and motivational factors.

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.

Impairment of HERG K(+) channel function by tumor necrosis factor-alpha: role of reactive oxygen species as a mediator

Congestive heart failure (CHF) is associated with susceptibility to lethal arrhythmias and typically increases levels of tumor necrosis factor-alpha (TNF-alpha) and its receptor, TNFR1. CHF down-regulates rapid delayed-rectifier K(+) current (I(Kr)) and delays cardiac repolarization. We studied the effects of TNF-alpha on cloned HERG K(+) channel (human ether-a-go-go-related gene) in HEK293 cells and native I(Kr) in canine cardiomyocytes with whole-cell patch clamp techniques. TNF-alpha consistently and reversibly decreased HERG current (I(HERG)). Effects of TNF-alpha were concentration-dependent, increased with longer incubation period, and occurred at clinically relevant concentrations. TNF-alpha had similar inhibitory effects on I(Kr) and markedly prolonged action potential duration (APD) in canine cardiomyocytes. Immunoblotting analysis demonstrated that HERG protein level was slightly higher in canine hearts with tachypacing-induced CHF than in healthy hearts, and TNF-alpha slightly increased HERG protein level in CHF but not in healthy hearts. In cells pretreated with the inhibitory anti-TNFR1 antibody, TNF-alpha lost its ability to suppress I(HERG), indicating a requirement of TNFR1 activation for HERG suppression. Vitamin E or MnTBAP (Mn(III) tetrakis(4-benzoic acid) porphyrin chloride), a superoxide dismutase mimic) prevented, whereas the superoxide anion generating system xanthine/xanthine oxidase mimicked, TNF-alpha-induced I(HERG) depression. TNF-alpha caused robust increases in intracellular reactive oxygen species, and vitamin E and MnTBAP abolished the increases, in both HEK293 cells and canine ventricular myocytes. We conclude that the TNF-alpha/TNFR1 system impairs HERG/I(Kr) function mainly by stimulating reactive oxygen species, particularly superoxide anion, but not by altering HERG expression; the effect may contribute to APD prolongation by TNF-alpha and may be a novel mechanism for electrophysiological abnormalities and sudden death in CHF.

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.

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.

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.

How to RECOVER from RENAISSANCE? The significance of the results of RECOVER, RENAISSANCE, RENEWAL and ATTACH

Two trial programmes testing an anti-cytokine medication in chronic heart failure (CHF) have been halted. In the RENAISSANCE and RECOVER trials (the combined analysis being termed RENEWAL), 2048 CHF patients were randomised to placebo or one of 3 doses of etanercept, a fusion protein directed against TNF. Within RENAISSANCE and RECOVER a clinical composite score was used to assess the clinical effects at 24 weeks (primary endpoint: alpha 0.04). Overall, the number of patients who were classified to have during the trial "improved", remained "unchanged" or "worsened" was similar for patients on placebo or any dose of etanercept (RENAISSANCE: p=0.17, RECOVER: p=0.34). In RENEWAL (combined analysis of medium and high dose etanercept vs. placebo), the primary endpoint (death or CHF hospitalisation, alpha 0.01) was not different between etanercept and placebo (RR 1.10, 95%CI 0.91 to 1.33, p=0.33). In RENEWAL, the secondary endpoint (death for any cause) was not different between etanercept and placebo (RR 1.13, 95%CI 0.86 to 1.50, p=0.39). ATTACH was a phase II, multicentre, randomised, double-blind, placebo-controlled pilot trial that aimed to evaluate the effects of infliximab (an antibody against TNF given in 2 different doses) in 150 CHF patients with stable NYHA class III or IV (in NYHA IV: <10%). In the placebo group (n=49), none of the patients died during 28 weeks of follow-up. At 14 (28) weeks, the endpoint of death or hospitalisation was reached in 2 (5) patients on placebo, in 2 (4) patients in the medium dose (5 mg/kg), and in 8 (13) patients in the high dose (10 mg/kg) of infliximab. During follow-up, compared to placebo the hazard to reach this endpoint was similar in the medium dose group (RR 0.80, 95%CI 0.22-2.99), but increased in the high dose group (RR 2.84, 95%CI 1.01-7.97, p<0.05).

CONCLUSION

At the respective lower doses there was no safety issue with regards to the use of either infliximab or etanercept. High dose anti-TNF therapy may not be useful in CHF patients, but the situation in lower doses and in patients with documented inflammatory/metabolic problems or in cardiac cachexia has not yet been adequately assessed.

Inflammatory mediators and the failing heart: past, present, and the foreseeable future

Recent studies have identified the importance of proinflammatory mediators in the development and progression of heart failure. The growing appreciation of the pathophysiological consequences of sustained expression of proinflammatory mediators in preclinical and clinical heart failure models culminated in a series of multicenter clinical trials that used "targeted" approaches to neutralize tumor necrosis factor in patients with moderate to advanced heart failure. However, these targeted approaches have resulted in worsening heart failure, thereby raising a number of important questions about what role, if any, proinflammatory cytokines play in the pathogenesis of heart failure. This review will summarize the tremendous growth of knowledge that has taken place in this field, with a focus on what we have learned from the negative clinical trials, as well as the potential direction of future research in this area.

Cachexia: a therapeutic approach beyond cytokine antagonism

Cachexia is seen in a number of chronic diseases, and it is always associated with a poor prognosis. Irrespective of etiology, the development of cachexia appears to share a common pathophysiological pathway. This includes induction of proteasome-dependent myofibril-degradation, which is thought to be secondary to stimulation by enhanced levels of pro-inflammatory cytokines. Elevation of tumor necrosis factor-alpha (TNFalpha) and other plasma cytokines has been demonstrated in many conditions associated with cachexia. Despite improved pathophysiological understanding, a specific treatment for cachexia has not yet been established. Whilst direct TNFalpha antagonism has therapeutic appeal, this review will focus on manipulation of downstream pathways and the potential benefits. For example, nuclear factor-kappaB (NF-kappaB) is one of the most important signal transducers of TNFalpha, and drugs targeting this signalling cascade might be useful in the treatment of cachexia. Although the use of some of these substances, for example glucocorticoids, remains controversial, others may prove beneficial in the treatment of this syndrome. The role of other approaches such as proteasome-inhibitors remains to be elucidated. Alternatively, interleukin-10 and other immunosuppressive cytokines may also be able to counterbalance certain features of 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.

Cytokines, apoptosis and cachexia: the potential for TNF antagonism

The cachexia syndrome is characterised by progressive weight loss and depletion of lean body mass and has long been recognised as a poor prognostic sign. Whilst the clinical features of the wasting process are readily apparent, its pathogenesis is complex and poorly understood. There is increasing evidence that the immune system, in particular inflammatory cytokines, may play an important role in the development of cachexia. The cytokine considered to be the most relevant to this process is tumor necrosis factor alpha (TNF), although other mediators such as interleukin (IL) 1, IL-6 and interferon gamma have also been implicated. Apoptosis represents a potential pathway by which wasting can occur in chronic diseases. Cytokines and their corresponding receptors are known to be important regulators of cell death. Apoptosis has been demonstrated in the skeletal muscle of patients with chronic heart failure (CHF) and is thought to be partly responsible for the significant impairment of functional work capacity associated with this condition. An understanding of the mechanisms that regulate muscle protein breakdown is essential for the development of strategies for treating or even preventing muscle cachexia in patients. It is the aim of this article to review the role of inflammatory cytokines, particularly TNF, in the pathogenesis of wasting and also the potential for anti-cytokine therapy. Although this review will concentrate predominantly on the syndrome of CHF, other chronic illnesses such as liver disease, cancer, and sepsis will also be discussed.

Exercise to prevent and treat functional disability

There are myriad ways in which optimal levels of physical activity over the course of the life span could potentially contribute to the prevention of functional disability in old age. These include direct effects of exercise to maximize physiologic capacity and prevent or delay the onset of disability-related conditions and more indirect effects, such as the modulation of psychosocial factors important in the expression of disability. Epidemiologic studies strongly suggest that functional disability is inversely related to physical activity level or physical fitness in various domains. Experimental studies confirm the benefits of exercise on correlates of disability, such as impairments of muscle strength or performance-based tests of functional limitations. However, the evidence that exercise can actually prevent disability in the long-term is not yet established by data from randomized clinical trials in the general population. Secondary prevention of disability in frail elders has been shown in a few trials. The available evidence, however, suggests that a rational exercise prescription for the prevention and treatment of disability at this time should include promotion of a physically active lifestyle and specific exercises targeting aerobic capacity, strength, and balance. Differential emphasis on specific elements of this prescription may be necessary and appropriate, depending on the etiology of the disability in specific cohorts, severity of physical impairments and functional limitations, and other individual characteristics relevant to exercise feasibility, safety, and efficacy.

Immune and neurohormonal pathways in chronic heart failure

Chronic heart failure is a complex disorder with interactions among the cardiovascular, immune, and neurohormonal systems. The concept that the progression of heart failure is due to neurohormonal abnormalities has received the greatest attention to date, leading to substantial therapeutic benefits. Although many current therapies are also thought to exert a variety of immunologic effects, this has been much less studied. In this review, the authors discuss a number of interactions among immune pathways and neurohormonal abnormalities relevant to heart failure. Cytokines, in particular tumor necrosis factor-alpha, have tremendous interactive opportunities within a regulatory network of energy metabolism, immune function, and neuroendocrine and hormonal function. Inflammatory cytokines are known to contribute to the progression of heart failure, and have been related to patients' prognosis. Advanced heart failure can be considered a state of chronic (low-grade) inflammation, and there are many reasons to suggest that anticytokine therapy could be successful in these patients. These novel approaches are certainly not without some risk, and many of them are very expensive, which may limit their application to certain subgroups of patients. In the future, it may not be enough to monitor cardiac function alone. Rather, the immune and neurohormonal status of patients may also need to be included in the performance of a complete assessment.

High tumour necrosis factor-alpha levels are associated with exercise intolerance and neurohormonal activation in chronic heart failure patients

Immune activation plays an important role in the progression of chronic heart failure (CHF). We sought to investigate whether different degrees of tumor necrosis factor-alpha (TNF-alpha) activation are associated with exercise intolerance, neurohormonal activation and alterations in muscle mass and function in patients with CHF without cardiac cachexia. Patients were divided into quartiles according to their TNF levels (first quartile: 0.98-4.90 pg/ml, second quartile: 5.00-6.60 pg/ml; third quartile 6.80-9.00 pg/ml; fourth quartile 9.80-32.00 pg/ml). Patients underwent cardiopulmonary exercise testing, quadriceps muscle strength test, quadriceps fatigue test, and assessment of thigh muscle and fat cross-sectional area (CSA) by computerized tomography scanning. Patients in the highest TNF quartile had the lowest peak oxygen consumption [13.1 (+/-4.1) ml/kg/min vs 18.1 (+/-5.3), 18.8 (+/-4.8) and 18.7 (+/-5.6) ml/kg/min, P<0.01] the greatest relation of ventilation and dioxide production (VE/VCO(2)) slope (P<0.05) and the most elevated catecholamine levels (P<0.05) compared to patients in the first three quartiles. Patients with the lowest TNF levels had preserved thigh muscle size and quadriceps strength. Strength/muscle CSA was similar in the four groups. Muscle strength during fatigue testing was significantly lower in the fourth quartile (P=0.01) compared with the other three groups. In CHF patients only the highest levels of TNF are associated with poor functional status and neurohormonal activation. This group of patients may represent the appropriate target population for TNF antagonism.

Recent insights into the role of tumor necrosis factor in the failing heart

Recent studies have identified the importance of biologically active molecules such as neurohormones in disease progression in heart failure. More recently it has become apparent that in addition to neurohormones, another portfolio of biologically active molecules termed cytokines, are also expressed in the setting of heart failure. This article will review recent clinical and experimental material which suggests that tumor necrosis factor (TNF), a pro-inflammatory cytokine, may contribute to disease progression in heart failure by virtue of the direct toxic effects that this molecule exerts on the heart and circulation.

Improvement of thigh muscles by neuromuscular electrical stimulation in patients with refractory heart failure: a single-blind, randomized, controlled trial

OBJECTIVE

To determine the impact of an 8-wk neuromuscular stimulation program of thigh muscles on strength and cross-sectional area in patients with refractory heart failure listed for transplantation.

DESIGN

Forty-two patients with a stable disease course were assigned randomly to a stimulation group (SG) or a control group (CG). The stimulation protocol consisted of biphasic symmetric impulses with a frequency of 50 Hz and an on/off regime of 2/6 sec.

RESULTS

Primary outcome measures were isometric and isokinetic thigh muscle strength and muscle cross-sectional area. Our results showed an increase of muscle strength by mean 22.7 for knee extensor and by 35.4 for knee flexor muscles. The CG remained unchanged or decreased by -8.4 in extensor strength. Cross-sectional area increased in the SG by 15.5 and in the CG by 1.7.

CONCLUSIONS

Activities of daily living as well as quality of life increased in the SG but not in the CG. Subscales of the SF-36 increased significantly in the SG, especially concerning physical functioning by +7.5 (1.3-30.0), emotional role by +33.3 (0-66.6), and social functioning by +18.8 (0-46.9), all P < 0.05. Neither a change nor a decrease was observed in the CG. Neuromuscular electrical stimulation of thigh muscles in patients with refractory heart failure is effective in increasing muscle strength and bulk and positively affects the perception of quality of life and activities of daily living.

Tumour necrosis factor in chronic heart failure: a peripheral view on pathogenesis, clinical manifestations and therapeutic implications

The development of chronic heart failure (CHF) includes phenotypic changes in a host of homeostatic systems so that, as the disease advances, CHF may be seen as a multi-system disorder with its origins in the heart but embracing many extra-cardiac manifestations. Immunological abnormalities are recognised in this context, in particular, changes in the expression of mediators of the innate immune response. Higher levels of the pro-inflammatory cytokine tumor necrosis factor (TNF) are found in the circulation and in the myocardium of patients with CHF than in controls, and TNF has been implicated in a number of pathophysiological processes that are thought important to the progression of CHF. Therapies directed against this cytokine therefore represent a novel approach to heart failure management. Anti-TNF strategies in CHF may target the mechanisms of immune activation, the intracellular pathways regulating TNF production, or the fate of TNF once it has been released into the circulation. Circulating endotoxin may be an important stimulus to TNF production by circulating monocytes, tissue macrophages and cardiac myocytes in CHF and efforts to limit this phenomenon are of interest. Several established pharmacological therapies for patients with CHF, including angiotensin converting enyzme inhibitors, beta-blockers, and phosphodiesterase inhibitors may modify cellular TNF production by their action on intracellular mechanisms, whereas TNF receptor fusion proteins have been developed that target circulating TNF itself. Patients with New York Heart Association class IV symptoms, those with cardiac cachexia and those with oedematous decompensation of their disease have the highest serum TNF levels and are most likely to benefit most from such a therapeutic approach.

The role of inflammatory mediators in chronic heart failure: cytokines, nitric oxide, and endothelin-1

There is now considerable evidence to suggest that neurohormonal and immune mechanisms may play a central role in the pathogenesis of chronic heart failure (CHF), which is likely to have important implications for the management of this condition. It has been proposed that CHF is a state of immune activation with inflammatory cytokines contributing to both the central and the peripheral manifestations of this syndrome. The immune system is the body's natural defence mechanism against infection and other stresses, which has several different components that interact with each other in a complex manner. The main components which are thought to be relevant to the pathogenesis of CHF are: cytokines, adhesion molecules, autoantibodies, nitric oxide, and endothelin-1, and this review will concentrate on these factors. This article will also discuss the potential role of anti-cytokine therapies in the treatment of CHF.

Pyrexia, procalcitonin, immune activation and survival in cardiogenic shock: the potential importance of bacterial translocation

AIMS

Exposure to bacterial endotoxin, perhaps due to bowel congestion or ischaemia and altered gut permeability, may result in immune activation that is characteristic for patients with severe heart failure. It is known that blood procalcitonin rises in response to bacterial endotoxin exposure.

METHODS

We measured procalcitonin in a group of 29 patients with acute cardiogenic shock and no sign of infection (all without bacteraemia) and 26 with septic shock. Blood was analysed for procalcitonin, interleukin-6, tumour necrosis factor-alpha (TNF-alpha), c-reactive protein (CRP) and neopterin. Patients were managed conventionally in an intensive care unit with no further experimental procedures.

RESULTS

Three cardiogenic (10%) and seven septic shock patients (27%) survived. Most patients with acute heart failure surviving 12 h or more (18 of 20) developed a pyrexia (738.0 degrees C) of unknown origin in the absence of positive cultures, with a rise in procalcitonin (1.4+/-0.8 to 48.0+/-16.2 ng/ml, P<0.001), CRP (76.5+/-16.4 to 154.7+/-22.9 mg/l, P<0.001) and neopterin (20.7+/-3.5 to 41.2+/-6.7 nmol/l, P<0.001). Patients with septic shock had higher initial levels of cytokines, and higher peak levels. Those with heart failure surviving (n=3) and those dying in the first 12 h (n=9) had no rise in cytokine levels. The patients with high procalcitonin had a higher temperature (38.9+/-0.3 vs. 37.3+/-0.23 degrees C, P<0.05), TNF-alpha (43.95+/-9.64 vs. 16.43+/-4.33 pg/ml; P<0.005) and CRP (146.1+/-18.4 vs. 68.2+/-39.6 mg/ml, P<0.005). Peak procalcitonin levels correlated with peak temperature (r=0.74, P<0.001).

CONCLUSION

Cardiogenic shock causes a pyrexia of unknown origin in patients surviving for 12 h and that is associated with a rise in procalcitonin levels. This lends support to the hypothesis that patients with cardiogenic shock may be being exposed to bacterial endotoxin at a time when bowel wall congestion and or ischaemia is likely to be present.

How are cytokines activated in heart failure?

In the dilated and failing heart, elevated LV end-diastolic wall stress causes myocardial expression of cytokines, which directly or indirectly influence LV contractile performance and remodeling [22]. Due to poor diffusion of cytokines into the coronary effluent, the contribution of this myocardial production to the raised plasma levels is probably limited. Raised plasma levels of cytokines in heart failure are therefore more likely the result of extramyocardial production because of altered tissue perfusion and tissue hypoxia possibly modulated by bacterial endotoxin release from the gut.

Cytokines in heart failure: pathogenetic mechanisms and potential treatment

Recent studies have shown that patients with heart failure overexpress a class of biologically active molecules, generically referred to as pro-inflammatory cytokines. This article will review recent clinical and experimental material that suggests that pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and interleukin-6 (IL-6) may play a role in the pathogenesis of congestive heart failure. In addition, we will review recent studies that suggest that antagonizing cytokines may represent a novel target for heart failure therapy.

Heart failure as a metabolic problem

Chronic heart failure (CHF) remains an important and increasing public health care problem. Not until recently it has been recognised that CHF is a chronic progressive disorder affecting different physiological and metabolic pathways. Nowadays CHF is reviewed as the consequence of an interplay of haemodynamic, neurohormonal, immunological, and endocrine mechanisms, initially thought to have beneficial adaptive effects for the organism to compensate the heart's inability to pump properly. However, these secondary changes eventually contribute to further deterioration of CHF. This review focuses on metabolic features observed in patients with CHF and discusses immunological and neuroendocrine aspects and their potential contribution to the pathogenesis of CHF. The overall evidence suggests that advanced CHF is a multifactorial metabolic syndrome that can lead to cardiac cachexia and then carries a very poor prognosis. Joint efforts of cardiologists, endocrinologists, and immunologists are required to develop therapeutic strategies able to improve the metabolic status of CHF patients.

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

BACKGROUND

Immune activation in patients with chronic heart failure may be secondary to endotoxin (lipopolysaccharide) action. We investigated the hypothesis that altered gut permeability with bacterial translocation and endotoxaemia would be increased in patients with oedema secondary to congestive heart failure.

METHODS

We compared 20 patients who had chronic heart failure with recent-onset peripheral oedema (mean age 64 years [SD 10], New York Heart Association [NYHA] class 3.3 [0.7]), 20 stable non-oedematous patients with chronic heart failure (mean age 63 years [19], NYHA class 2.6 [0.7]), and 14 healthy volunteers (mean age 55 years [16]). Biochemical markers of endotoxaemia, inflammation, and immune activation were measured. Ten patients were studied within 1 week of complete resolution of oedema. Five patients survived longer than 6 months and were restudied again after remaining free of oedema for more than 3 months.

FINDINGS

Mean endotoxin concentrations were higher in oedematous patients with chronic heart failure than in stable patients with chronic heart failure (0.74 [SD 0.45] vs 0.37 EU/mL [0.23], p=0.0009) and controls (0.46 EU/mL [0.21], p=0.02). Oedematous patients had the highest concentrations of several cytokines. After short-term diuretic treatment, endotoxin concentrations decreased from 0.84 EU/mL [0.49] to 0.45 EU/mL [0.21], p<0.05) but cytokines remained raised. After freedom of oedema for more than 3 months after oedema resolved, endotoxin concentrations remained unchanged from the previous visit (0.49 EU/mL [0.06], p=0.45).

INTERPRETATION

Raised concentrations of endotoxin and cytokines are found in patients with chronic heart failure during acute oedematous exacerbation. Intensified diuretic treatment can normalise endotoxin concentrations. Our preliminary findings suggest that endotoxin may trigger immune activation in patients with chronic heart failure during oedematous episodes.

An overview of tumor necrosis factor alpha and the failing human heart

Recent studies have identified the importance of biologically active molecules (e.g., neurohormones) in disease progression in heart failure. In addition to neurohormones, another portfolio of biologically active molecules, termed cytokines, are also expressed in the setting of heart failure. This article reviews recent clinical and experimental material that suggest that the cytokines (e.g., tumor necrosis factor alpha), much like the neurohormones, may represent another class of biologically active molecules that are responsible for the development and progression of heart failure.

Insights into the pathogenesis of chronic heart failure: immune activation and cachexia

Body wasting, i.e, cardiac cachexia, is a complication of chronic heart failure (CHF). The authors have suggested that cardiac cachexia should be diagnosed when nonedematous weight loss of more than 7.5% of the premorbid normal weight occurs over a time period of more than 6 months. In an unselected CHF outpatient population, 16% of patients were found to be cachectic. The cachectic state is predictive of poor survival independently of age, functional class, ejection fraction, and exercise capacity. Patients with cardiac cachexia suffer from a general loss of fat, lean, and bone tissue. Cachectic CHF patients are weaker and fatigue earlier. The pathophysiologic causes of body wasting in patients with CHF remain unclear, but initial studies have suggested that humoral neuroendocrine and immunologic abnormalities may be of importance. Cachectic CHF patients show increased plasma levels of catecholamines, cortisol, and aldosterone. Several studies have shown that cardiac cachexia is linked to increased plasma levels of tumor necrosis factor alpha. The degree of body wasting is strongly correlated with neurohormonal and immune abnormalities. Some investigators have suggested that endotoxin may be important in triggering immune activation in CHF patients. Available studies suggest that cardiac cachexia is a multifactorial neuroendocrine and immunologic disorder that carries a poor prognosis. A complex catabolic-anabolic imbalance in different body systems may cause body wasting in patients with CHF.

Cardiac cachexia: a syndrome with impaired survival and immune and neuroendocrine activation

Chronic heart failure (CHF) is a complex syndrome affecting many body systems. Body wasting (ie, cardiac cachexia) is a serious complication of CHF long known but little investigated. Although no specific diagnostic criteria have been established, we have suggested that cardiac cachexia be defined on the basis of the presence of documented nonintentional and nonedematous weight loss > 7.5% of the premorbid normal weight, occurring over a time period of > 6 months. Using this definition, 16% of an unselected CHF outpatient population was found to be cachectic. The cachectic state is predictive of impaired prognosis independently of age, functional disease classification, left ventricular ejection fraction, and peak oxygen consumption. The mortality in the cachectic cohort is 50% at 18 months. Analyzing body composition in detail, it has been found that patients with cardiac cachexia suffer from a general loss of fat tissue (ie, energy reserves), lean tissue (ie, skeletal muscle), and bone tissue (ie, osteoporosis). 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 initial cross-sectional studies have suggested that humoral neuroendocrine and immunologic abnormalities are linked, independently of established heart failure severity markers, to the presence of body wasting. Comparing the features of cachectic and noncachectic CHF patients with those of healthy control subjects, it is mainly the cachectic CHF patients who show raised plasma levels of epinephrine, norepinephrine, and cortisol; the highest plasma renin activity and aldosterone plasma concentrations; and the lowest plasma sodium level. Several studies have shown that cardiac cachexia is linked to raised plasma levels of tumor necrosis factor-ac. 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.