Effect of noradrenaline and isoproterenol on lipopolysaccharide-induced tumor necrosis factor-alpha production in whole blood from patients with chronic heart failure and the role of beta-adrenergic receptors

Increased levels of tumor necrosis factor-alpha (TNF-alpha) correlate with poor prognoses in chronic heart failure (CHF). This study demonstrated that noradrenaline and isoproterenol inhibit TNF-alpha production in patients with CHF in ex vivo whole blood in a dose-dependent fashion. The beta-blocker bisoprolol abolishes this effect.

Heat shock protein 70 in patients with chronic heart failure: relation to disease severity and survival

BACKGROUND

Heat shock protein 70 (Hsp70) is essential for cellular recovery, survival and maintenance of cellular function. Research into the possible use of Hsp70 as a cytoprotective therapeutic agent is ongoing. Chronic heart failure (CHF) is a state associated with systemic inflammation, particularly in patients with cardiac cachexia. We hypothesised that circulating Hsp70 levels are elevated in patients with CHF, more so in cachechtic patients, and that Hsp70 levels would relate to mortality.

METHODS AND RESULTS

We studied 107 patients (28 female, age 67+/-1 years, NYHA class 2.6+/-0.6 and LVEF 29+/-1%, mean+/-SEM) and 21 controls. Cardiac cachexia was present in 32 patients. Hsp70 was detectable in 41% of CHF patients and in only 10% of controls. Overall serum levels were significantly higher in CHF patients vs. controls (7.13+/-1.34 vs. 0.38+/-0.26 ng/ml, p=0.004). Hsp70 levels were also higher in patients with advanced CHF according to NYHA class or the presence of cachexia (all p<0.05). There was no relation between Hsp70 and left ventricular ejection fraction, maximal oxygen consumption and several inflammatory cytokines (all p>0.05). During a median follow-up of 208 days (range 4-2745 days) 38 patients died. Cox proportional hazards analysis showed that increased Hsp70 did not predict survival (p=0.17).

CONCLUSION

Hsp70 levels are elevated in CHF patients, particularly in those with cardiac cachexia and Hsp70 relates to disease severity but not to survival. The significance of the relationship of Hsp70 expression and morbidity in CHF needs further evaluation.

Anaemia is an independent predictor of poor outcome in patients with chronic heart failure

BACKGROUND

Mild anaemia frequently occurs in patients with chronic heart failure (CHF), particularly in the advanced stages of the disease. The correction of anaemia with erythropoietin is a therapeutic possibility. The aim of this study was to assess prospectively the relationship between the prevalence of anaemia (haemoglobin level<or=120 g/l) and prognosis in an unselected CHF population.

METHODS

All consecutive patients with a diagnosis of CHF admitted to our department between January 2000 and April 2000 were considered for the present study. Those with secondary causes of anaemia were excluded. Patients were followed up until November 2001 (>18 months in all survivors), and the end-point of the study was all-cause mortality.

RESULTS

A total of 176 patients were enrolled (mean age: 63 years, New York Heart Association (NYHA) classification I/II/III/IV: 15/81/51/29; left ventricular ejection fraction (LVEF): 42%, ischaemic aetiology in 62%). In the whole population the mean haemoglobin level was 140+/-15 g/l. Anaemia was found in 18 (10%) patients, and was significantly more common in women than in men (18 vs. 7%, respectively, P=0.02) and in those with most severe CHF symptoms (frequency in NYHA I/II/III/IV: 0/9/10/21%, respectively; NYHA IV vs. I-III, P=0.03), but not related to the other clinical indices. Univariate analysis revealed NYHA class III-IV (hazard ratio 3.8, 95% CI: 1.6-8.9, P=0.003), low LVEF <35% (hazard ratio 2.3, 95% CI: 1.0-4.9, P=0.04) and anaemia (hazard ratio 2.9, 95% CI: 1.2-7.2, P=0.02) as predictors of 18-month mortality. In multivariate analysis, anaemia remained an independent predictor of death when adjusted for NYHA class and LVEF (hazard ratio: 2.6, 95% CI: 1.0-6.5, P=0.04). In anaemic patients, 18-month survival was 67% (95% CI: 45-89%) compared to 87% (81-92%) in patients with a normal haemoglobin level (P=0.016).

CONCLUSIONS

Mild anaemia is a significant and independent predictor of poor outcome in unselected patients with CHF. Correction of low haemoglobin level may become an interesting therapeutic option for CHF patients.

Growth hormone resistance in chronic heart failure and its therapeutic implications

BACKGROUND

In recent years the administration of recombinant human growth hormone (GH) has received great attention. This review compares the potential of this therapeutic intervention in heart failure with that in other diseases where wasting is commonly seen. The pathophysiologic importance of GH and insulin-like growth factor (IGF)-I in these conditions will be discussed.

METHODS AND RESULTS

Abnormalities of the GH-IGF-I axis play an important role in the development of cachexia in chronic illnesses. GH resistance is a major determinant of the wasting process, acting through several different mechanisms: increased catabolism, impaired anabolism, and enhanced apoptosis in peripheral tissues. GH therapy has been evaluated in chronic heart failure (CHF); acquired GH resistance may explain the general lack of therapeutic success in the majority of studies. The assessment of plasma levels of GH, IGF-I, and, in particular, GH binding protein may help to guide dosing of GH for CHF patients.

CONCLUSIONS

GH resistance might be overcome by use of intermittent or higher doses of GH, or alternatively by combining GH with IGF-I. Randomized studies of GH therapy in catabolic states, with targeted dosing and longer duration of treatment are required to fully assess the safety and efficacy of this treatment approach.

Myocardial production of C-type natriuretic peptide in chronic heart failure

BACKGROUND

C-type natriuretic peptide (CNP) is a vasodilator produced by the vascular endothelium. It shares structural and physiological properties with the cardiac hormones atrial natriuretic peptide and brain natriuretic peptide (BNP), but little is known about its pathophysiological role in chronic heart failure (CHF). We assessed the hypothesis that CNP is produced by the heart in patients with CHF.

METHODS AND RESULTS

Myocardial CNP production was determined (difference in plasma levels between the aortic root and coronary sinus [CS]) in 9 patients undergoing right and left heart catheterization as part of their CHF assessment (all male, age 59+/-9 years; New York Heart Association class 2.2+/-0.1; left ventricular ejection fraction 29+/-5%; creatinine 105+/-8 micro mol/L [all values mean+/-SEM]). BNP, established as originating from myocardium, was assessed from the same samples as a positive control. Analyses were performed by a blinded operator using a standard competitive radioimmunoassay kit (Peninsula Laboratories, Bachem Ltd UK). A step-up (29%) in plasma CNP concentration was found from the aorta to the CS (3.55+/-1.53 versus 4.59+/-1.54 pg/mL, respectively; P=0.035). The mean increase in CNP was 0.90+/-0.35 pg/mL (range 0.05 to 2.80 pg/mL). BNP levels increased by 57% from aorta to CS (86.0+/-20.5 versus 135.0+/-42.2 pg/mL; P=0.01). CS CNP levels correlated with mean pulmonary capillary wedge pressure (r=0.82, P=0.007).

CONCLUSIONS

We have shown that CNP is produced by the heart in patients with CHF. Although further evaluation is required to define its full pathophysiological role in this condition, CNP may represent an important new local mediator in the heart.

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.

Clinical characteristics and survival of patients with chronic heart failure and prolonged QRS duration

BACKGROUND

Abnormal prolongation of QRS duration is a common finding in patients with chronic heart failure, and is associated with an impaired prognosis. The optimum QRS duration for separating chronic heart failure patients with respect to prognosis has not been determined. Whilst resynchronisation of ventricular conduction may benefit patients with QRS>150 ms, this has yet to be determined for patients with moderate QRS prolongation.

METHODS

We evaluated 155 patients with chronic heart failure (New York Heart Association class 2.6+/-0.8, mean+/-S.D.). The mean follow-up period was 838+/-748 days. Patients were sub-grouped according to QRS duration: <120 ms (normal QRS, n=82), 120-150 ms (moderate prolongation, n=44) and >150 ms (severe prolongation, n=29).

RESULTS

The optimal QRS duration for stratifying patients for 2-year event free survival was 120 ms (receiver operating characteristic analysis: area under curve 0.73; 95% CI 0.64-0.81). Moderate prolongation of QRS duration was associated with a worse New York Heart Association class, peak oxygen consumption and left ventricular ejection fraction when compared to patients with normal QRS duration (all P<0.05). Patients with moderate prolongation of QRS duration had similar impairment of New York Heart Association class and peak oxygen consumption as compared with patients with QRS duration >150 ms (all P>0.05).

CONCLUSIONS

The optimum QRS duration for stratifying patients for medium to long-term event-free survival was 120 ms. Heart failure patients with moderate QRS prolongation share similar impairment of exercise capacity and functional class to those with severe prolongation.

DANAMI-2: is primary angioplasty superior to thrombolysis in acute MI when the patient has to be transferred to an invasive centre?

Primary angioplasty is superior to thrombolysis in acute myocardial infarction when performed in a timely manner but the benefits are unknown when inter-hospital transfer is required for angioplasty. On the 20th March 2002 at the American College of Cardiology 51st Annual Scientific Session, the results of the Danish Multicentre Randomized Trial on Thrombolytic Therapy versus Acute Coronary Angioplasty in Acute Myocardial Infarction (DANAMI-2) were presented. 1,572 patients were randomized to front loaded tPA or angioplasty on presentation within 12 h of acute myocardial infarction; 1,129 from hospitals requiring transfer for up to 3 h for angioplasty. The trial was stopped early since there was a 40% relative reduction in the composite primary end-point of death, disabling stroke or reinfarction within 30 days (absolute reduction 13.7 to 8%, p=0.0003) with primary angioplasty. This appeared to be driven by a significant reduction of reinfarction from 6.3 to 1.6%. Ambulance transfer was shown to be safe but time to angioplasty was approximately 60 min longer than time to thrombolysis. No data are as yet available on the relative infarct sizes or left ventricular function in the two groups. The management of acute myocardial infarction is an area of missed opportunities. Patients present late to hospital, up to 30% of eligible patients do not receive reperfusion therapy and door to needle time is longer than is ideal. Whilst we await the full details of the trial and long term follow-up, we should not forget the challenges of conventional management of acute myocardial infarction.

Do results of the ENABLE (Endothelin Antagonist Bosentan for Lowering Cardiac Events in Heart Failure) study spell the end for non-selective endothelin antagonism in heart failure?

The last two decades have seen major advances in the treatment of chronic heart failure, primarily as a result of therapeutic manipulation of activated neurohormonal systems. Despite this progress, many patients still suffer significant morbidity and premature death. Antagonism of the biological effects of endothelin, a potent vasoconstrictor, represents a further potential target. To date, positive results from animal models of heart failure have not been translated into clinical practice, perhaps as a consequence of the high doses of drug used. The ENABLE (Endothelin Antagonist Bosentan for Lowering Cardiac Events in Heart Failure) study evaluated the effects of low dose bosentan, a non-selective endothelin receptor antagonist, in patients with severe heart failure (left ventricular ejection fraction <35%, New York Heart Association class IIIb-IV). A total of 1,613 patients were randomized to receive either bosentan (125 mg twice a day) or placebo. The preliminary results were presented at the 51st Annual Scientific Session of the American College of Cardiology (17-20 March 2002, Atlanta, GA, USA). The primary endpoint of all-cause mortality or hospitalization for heart failure was reached in 321/808 patients on placebo and 312/805 receiving bosentan. Treatment with bosentan appeared to confer an early risk of worsening heart failure necessitating hospitalization, as a consequence of fluid retention. It has been suggested that further studies using even lower doses of bosentan or more aggressive concomitant diuretic therapy may avoid this adverse effect. The results from the ENABLE study have, however, thrown further doubt on the potential benefits of non-specific endothelin receptor blockade in heart failure.

Regulation of lipolysis: natriuretic peptides and the development of cachexia

The development of cachexia is commonly seen in many pathological states and is associated with a markedly impaired prognosis. Loss of fat tissue appears to be of particular pathophysiological importance in this setting. Lipolysis is closely regulated in health; the major established pathways involving catecholamines (stimulation of lipolysis) and insulin (inhibition of lipolysis). The wasting process in cachexia is associated with marked metabolic dysfunction, and loss of this tight regulatory control. Natriuretic peptides are a family of related peptides with important vasodilatory, natriuretic and diuretic properties. It has recently been shown that natriuretic peptides are also potent stimuli for lipolysis in humans. In this respect, atrial and brain natriuretic peptide appear to have the greatest lipolytic effect, and are similar in potency to catecholamines. Elevated levels of circulating natriuretic peptides are found in several pathological states, and generally reflect disease severity. This article will provide a concise review of the regulation of lipolysis in humans, concentrating on the role of the natriuretic peptides. The relevance of natriuretic peptides to the development of cachexia will be discussed.

Neurohormonal activation and the chronic heart failure syndrome in adults with congenital heart disease

BACKGROUND

Neurohormonal activation characterizes chronic heart failure, relates to outcome, and is a therapeutic target. It is not known whether a similar pattern of neurohormonal activation exists in adults with congenital heart disease and, if so, whether it relates to common measures of disease severity or whether cardiac anatomy is a better discriminant.

METHODS AND RESULTS

Concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), endothelin-1 (ET-1), renin, aldosterone, norepinephrine, and epinephrine were determined in 53 adults with congenital heart disease, comprising 4 distinct anatomic subgroups (29 female; 33.5+/-1.5 years of age; New York Heart Association class 2.0+/-0.1, mean+/-SEM) and 15 healthy control subjects (8 female; 32.3+/-1.3 years of age). Systemic ventricular function was graded by a blinded echocardiographer as normal or mildly, moderately, or severely impaired. Adults with congenital heart disease had elevated levels of ANP (56.6 versus 3.1 pmol/L), BNP (35.8 versus 5.7 pmol/L), ET-1 (2.5 versus 0.7 pmol/L, all P<0.0001), renin (147 versus 16.3 pmol/L), norepinephrine (2.2 versus 1.6 pmol/L, both P<0.01) and aldosterone (546 versus 337 pmol/L, P<0.05). There was a highly significant stepwise increase in ANP, BNP, ET-1, and norepinephrine according to New York Heart Association class and systemic ventricular function, with even asymptomatic patients having evidence of significant neurohormonal activation. In contrast, there was no direct relationship between the 4 anatomic subgroups and any of the neurohormones studied.

CONCLUSIONS

Neurohormonal activation in adult congenital heart disease bears the hallmarks of chronic heart failure, relating to symptom severity and ventricular dysfunction and not necessarily to anatomic substrate. Neurohormonal antagonism across this large and anatomically diverse population should be considered.

The regulation and measurement of plasma volume in heart failure

Plasma volume, the intravascular portion of the extracellular fluid volume, can be measured using standard dilution techniques with radiolabeled tracer molecules. In healthy persons, plasma volume remains relatively constant as a result of tight regulation by the complex interaction between neurohormonal systems involved in sodium and water homeostasis. Although chronic heart failure (CHF) is characterized by activation of many of these neurohormonal systems, few studies have evaluated plasma volume in this condition under treatment. Untreated edematous decompensated heart failure (HF) is associated with a significant expansion of plasma volume. Patients with stable CHF, receiving conventional therapy, appear to have a contracted plasma volume, a concept that is in contrast to the widely held belief that CHF is associated with long-term hypervolemia. It is likely that significant changes in plasma volume occur during intensification of medical therapy or during transition from the edematous to the stable state. Clinical assessment of plasma volume may be of particular value during treatment in patients with decompensated HF, in whom the plasma volume is contracted despite an increase in total extracellular fluid volume. Under these circumstances, treatment with inotropes or renal vasodilators may be more appropriate than intravenous diuretics alone. Further studies evaluating plasma volume in HF may help to improve our understanding of the pathophysiologic mechanisms occurring in the development and progression of this complex condition.