Effect of low dose beta blockers on atrial and ventricular (B type) natriuretic factor in heart failure: a double blind, randomised comparison of metoprolol and a third generation vasodilating beta blocker

The effect of carvedilol on B-type natriuretic peptide and cardiac function in patients with heart failure and persistent atrial fibrillation

OBJECTIVES

We sought to determine the relationship between changes in natriuretic peptides and symptoms as a consequence of introducing beta-blocker therapy, in patients with chronic heart failure (CHF) and persistent atrial fibrillation (AF).

METHODS

In a randomised, double-blind, placebo-controlled study involving 47 patients with CHF and persistent AF (mean age 68 years and 62% men), we analysed the individual change (Δ) in B-type natriuretic peptide (BNP) level to the introduction of carvedilol (titrated to a target dose of 25 mg twice daily, group A) or placebo (group B) in addition to background treatment with digoxin. Symptoms score, 6-min walk distance, New York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF), heart rate (24-hour ECG) and BNP were measured at baseline and at 4 months.

RESULTS

LVEF (Δ median +5 vs. +0.4, p = 0.048), symptoms score (Δ median -4 vs. 0, p = 0.04), NYHA class (Δ median -33% vs. +3% in NYHA class 3-4, p = 0.046) and heart rate [Δ median 24-hour ventricular rate (VR) -19 vs. -2, p < 0.0001] improved with combination therapy of digoxin and carvedilol compared to digoxin alone, but BNP (Δ median +28 vs. -6 , p = 0.11) trended in the opposite direction. There was no relationship between the degree of symptomatic improvement or VR control and BNP response.

CONCLUSION

After the introduction of carvedilol, clinical outcome appears unrelated to BNP changes in patients with CHF and AF. Changes in BNP cannot be used as a marker of clinical response in terms of symptoms or cardiac function in this setting.

The Value of N-Terminal Pro–B-Type Natriuretic Peptide in Determining Antihypertensive Benefit

We investigated 3 hypotheses: (1) N-terminal pro–B-type natriuretic peptide (NT-proBNP) predicts cardiovascular disease events in patients with hypertension, (2) NT-proBNP is associated with blood pressure variability, and (3) NT-proBNP predicts benefit from antihypertensive regimens. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) randomized a subset of 6549 patients at risk with no history of coronary heart disease to either atenolol-based or amlodipine-based blood pressure–lowering treatment. During 5.5 years of follow-up, 485 cardiovascular disease cases accrued and were matched with 1367 controls. Baseline and 6-month in-trial NT-proBNP were measured. The results show that NT-proBNP improves cardiovascular disease risk prediction beyond established predictors, continuous net reclassification improvement of 22.3% ( P <0.0001). Furthermore, a 1-mm Hg increase in the SD of systolic blood pressure was associated with 2% higher baseline NT-proBNP in a multivariable regression analysis ( P <0.0001). However, NT-proBNP predicted cardiovascular disease risk independently of blood pressure variation (odds ratio per SD increase in log NT-proBNP 1.24; 95% confidence interval, 1.06–1.45; P =0.007). Atenolol-based treatment led to a 69.6% increase in NT-proBNP at 6 months ( P <0.0001). In contrast, amlodipine-based treatment reduced NT-proBNP by 36.5% ( P <0.0001). Amlodipine recipients who achieved a 6-month NT-proBNP below the median (61 pg/mL) were at lower risk of cardiovascular disease when compared with those who did not (odds ratio, 0.58; 95% confidence interval, 0.37–0.91) after adjustment for confounders inclusive of baseline NT-proBNP and achieved blood pressure. If confirmed, these novel results suggest that NT-proBNP, as well as aiding cardiovascular disease risk assessment, may also help assess the efficacy of specific antihypertensive regimens. Further relevant studies seem warranted.

Natriuretic Peptide testing in primary care

The incidence, as well as the morbidity and mortality associated with heart failure (HF) continue to rise despite advances in diagnostics and therapeutics. A recent advance in the diagnostic and therapeutic approach to HF is the use of natriuretic peptide (NP) testing, including both B-type natriuretic peptide (BNP) and its amino terminal cleavage equivalent (NT-proBNP). NPs may be elevated at an early stage among those with symptoms as well among those without. The optimal approach for applying NP testing in general populations is to select the target population and optimal cut off values carefully. Superior diagnostic performance is observed among those with higher baseline risk (such as hypertensives or diabetics). As well, unlike for acute HF, the cut off value for outpatient testing for BNP is 20-40 pg/mL and for NTproBNP it is 100-150 ng/L. In symptomatic primary care patients, both BNP and NT-proBNP serve as excellent tools for excluding HF based on their excellent negative predictive values and their use may be cost effective. Among those with established HF, it is logical to assume that titration of treatment to achieve lower NPs levels may be advantageous. There are several ongoing trials looking at that prospect.

Natriuretic peptide-guided management of acutely destabilized heart failure: rationale and treatment algorithm

Natriuretic peptides (B-type natriuretic peptide [BNP] and N-terminal pro-B-type natriuretic peptide [NT]-proBNP) have been proven to be strong diagnostic and prognostic tools in the assessment of acutely decompensated heart failure. The emergence of BNP/NT-proBNP testing as a standard of care in this setting has helped to reduce healthcare costs, and may decrease adverse clinical outcomes. The use of BNP and NT-proBNP to "guide" treatment of acutely destabilized heart failure has recently grown. We present an overview of the value of BNP/NT-proBNP in the context of acute heart failure management and therapy optimization, and present an algorithm for natriuretic peptide-guided treatment of acutely destabilized heart failure.

Outpatient monitoring and treatment of chronic heart failure guided by amino-terminal pro-B-type natriuretic peptide measurement

Amino-terminal pro-B-type natriuretic peptide (NT-proBNP) is a strong and independent prognostic marker in patients across the spectrum of heart failure (HF) stages, including patients managed in the outpatient setting. Serial measures of NT-proBNP are more valuable than single measures for prognosis, and biologic variation of the marker should allow serial monitoring. Furthermore, given that NT-proBNP levels decrease in response to the addition of therapies with proven benefit for HF (including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, diuretics, spironolactone, exercise therapy, and biventricular pacing), it is logical to expect that targeting therapy to decrease NT-proBNP levels may facilitate more optimal use of proven HF therapies and may reduce adverse clinical outcomes. The optimal strategy for NT-proBNP monitoring with regard to frequency of testing or whether to use standard or individualized targets is still being determined. Preliminary results are promising for targeting an outpatient NT-proBNP concentration of approximately < or =1,000 ng/L. Current data suggest that when NT-proBNP levels are not at goal or increase from prior measurements, the risk for hazard is increased. Adjustments in treatment and serial clinical follow-up with NT-proBNP retesting should be considered at frequent intervals until biochemical stabilization or achievement of a maximally tolerated medical program.

Does NT-proBNP remain a sensitive biomarker for chronic heart failure after administration of a beta-blocker?

BACKGROUND

Beta-blockers exert complex effects on plasma N-terminal-pro-B-type natriuretic peptide (NT-proBNP) level.

HYPOTHESIS

We aimed to investigate whether NT-proBNP was still able to mirror the severity of chronic heart failure and predict the prognosis of the disease after administration of a beta-blocker.

METHODS

Forty-four patients with chronic congestive heart failure were enrolled in the study to randomly receive carvedilol or bisoprolol in addition to background therapy. These patients underwent clinical measurement and blood sampling for NT-proBNP measurement at baseline and 3 or 7 months after the addition of the beta-blocker. The patients were followed-up for 3 years in order to register the occurrence of all-cause death.

RESULTS

NT-proBNP level showed a positive correlation with the severity of heart failure as evaluated by New York Heart Association (NYHA) classification both before and after administration of either beta-blocker. The relationship between NT-proBNP and NYHA class was not weakened with the duration of therapy. Furthermore, NT-proBNP was the only independent predictor of all-cause mortality both before and after administration of either beta-blocker. Left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter (LVEDD), age, NYHA class and treatment group were not independently predictive of mortality in this study.

CONCLUSIONS

The ability of NT-proBNP to reflect the severity and to predict the endpoint in chronic heart failure is not undermined after administration of a beta-blocker, suggesting that NT-proBNP remains a sensitive biomarker for chronic heart failure both before and after administration of a beta-blocker.

Cost effectiveness of the B type natriuretic peptide, electrocardiography, and portable echocardiography for the assessment of patients from the community with suspected heart failure

To analyze the cost efficiency of guidelines proposed by the European Society of Cardiology for investigation of patients in the community with suspected heart failure (HF). The guidelines recommend electrocardiography (ECG) and/or measurement of N-terminal pro B type natriuretic peptide (NTproBNP) prior to referral for echocardiography. Portable echocardiography is a new but validated technique for the evaluation of HF. Accordingly, 137 suspected HF patients (mean age 71+/-13 years) from the community underwent ECG and NTproBNP estimation prior to portable echocardiography. Cost effective analysis for ECG, NTproBNP, portable echocardiography and a combination of these; to define valvular heart disease, right ventricular dysfunction and left ventricular systolic and diastolic dysfunction were compared. The cost of abnormal NTproBNP followed by portable echocardiography, abnormal ECG followed by portable echocardiography and portable echocardiography alone for the detection per case of left ventricular systolic dysfunction were 313 euro, 310 euro, and 296 euro respectively and that for detection per case of any of the aforementioned cardiac abnormalities were 198 euro, 223 euro, and 170 euro respectively. Portable echocardiography alone for the assessment of suspected HF patients resulted in a cost reduction of up to 1083 euro for the detection per case of cardiac abnormality. While a strategy where initial NTproBNP estimation is cost effective in detecting any causes of heart failure, portable echocardiography remains the most costeffective strategy to assess patients from the community with suspected heart failure.

The effects of medications on circulating levels of cardiac natriuretic peptides

Circulating cardiac natriuretic peptide levels are being used increasingly in a range of clinical circumstances. Since it is evident that drugs used in the treatment of cardiovascular disorders can modulate natriuretic peptide levels, we here review the literature documenting these effects. Diuretics, blockers of the renin-angiotensin system, vasodilator agents, dopamine-like agonists, amiodarone, and perhaps allopurinol and statins suppress natriuretic peptide levels, most obviously in heart failure. Beta-blockers stimulate natriuretic peptide concentrations in hypertensive subjects, whereas in heart failure they have little effect or are stimulatory in the short term and inhibitory with sustained therapy. Digitalis compounds and aspirin tend to increase natriuretic peptide levels, and calcium channel blocking agents have varying effects depending on the individual drug and duration of administration. The effects of other drugs are less clear. Additional information is needed regarding the effects of medications along with dissection of the role of altered cardiac secretion versus changes in plasma clearance as explanation for drug-induced perturbations in natriuretic peptide concentrations. In the meantime, clinicians need to consider the known effects of medications when interpreting plasma levels of the cardiac natriuretic peptides.

Effects of immunoadsorption on the nt-BNP and nt-ANP plasma levels of patients suffering from dilated cardiomyopathy

Immunoadsorption (IA) represents an additional therapeutic approach in patients with severe heart failure due to dilated cardiomyopathy (DCM). nt-BNP and nt-ANP plasma levels are prognostic markers in patients with heart failure. The effect of IA on nt-BNP and nt-ANP plasma levels is unknown. In this case control study, 30 patients suffering from severe heart failure (LVEF < 35%) due to DCM were included. In 15 patients, IA was carried out in four courses of monthly intervals until month 3. For analysis of the acute and prolonged effects, the plasma levels of nt-BNP and nt-ANP were determined before and after each IA course. In 15 comparable DCM patients (controls), plasma levels of nt-BNP and nt-ANP were determined at baseline and after 3 months. LVEF remained stable during this study in the control group. In contrast, in the IA group after 3 months, LVEF increased from 29.7 +/- 1 to 38.6 +/- 2%, P < 0.001. In the control group, the nt-BNP and nt-ANP plasma levels remained stable during the 3 months of the study. In the IA group after the first IA course, the level of nt-BNP was acutely reduced from 1501 +/- 328 to 925 +/- 151 fmol/mL, P < 0.01. In addition, the nt-ANP level was reduced from 4439 +/- 1271 to 2897 +/- 825 fmol/mL, P < 0.01. In the IA group, the reduction of these two parameters remained detectable after 3 months before the last course: nt-BNP: 714 +/- 119 fmol/mL, nt-ANP: 2227 +/- 427 fmol/mL, P < 0.05. The improvement of left ventricular function during IA is accompanied by a reduction of nt-BNP and nt-ANP plasma levels in patients with DCM.

Brain natriuretic peptide (BNP) testing in the emergency department

In the past decade a large amount of attention has been focused on brain natriuretic peptide (BNP) testing in the evaluation of patients with acute dyspnea as well as the screening of patients for congestive heart failure (CHF). Because BNP is secreted by myocytes in response to ventricular stretch, it has long been thought that BNP could become a biochemical marker for CHF. Rapid assays have been developed and BNP testing has been studied in detection of CHF and predictive outcomes in a large variety of settings. We review the clinical evidence associated with the use of BNP testing in the acute care setting. We conclude with a discussion of clinical utility in the emergency department for the evaluation of patients presenting with acute dyspnea.

[Brain natriuretic peptide in primary care: diagnostic value in heart failure]

OBJECTIVE

To determine the validity and usefulness of brain natriuretic peptide (BNP) for diagnosing left ventricular dysfunction (LVD).

DESIGN

Prospective, descriptive, multi-centred study to validate the diagnostic test.

SETTING

Primary care centres in the Community of Madrid, Spain.

PARTICIPANTS

Consecutive sample of patients at high risk of presenting with LVD.

INTERVENTIONS

Data will be gathered from anamnesis, physical examination, ECG, and chest x-ray to find the risk factor(s) for LVD and the presence or absence of symptoms of congestive heart failure according to the Framingham scale. BNP will be determined at PC clinics in all patients who meet the inclusion criteria, using the "triage BNP test." All patients included in the study will be referred to an echocardiography service for an echocardiogram, which will be the gold standard test. Two independent cardiologists will evaluate the echocardiograph without knowing the BNP values.

MAIN MEASUREMENTS

BNP concentrations will be compared against the kind and degree of LVD. ROC curves analysis will test the capacity of BNP to diagnose LVD. Optimal sensitivity and specificity value will be calculated by means of the position on the curve resulting from the minimum distance at the cut-off point for best sensitivity and specificity. Then, sensitivity, specificity, and positive and negative predictive values will be calculated.

DISCUSSION

BNP can complement the information provided by other diagnostic tests. It should be included as an important factor in the taking of clinical-therapeutic decisions.

Introduction of metoprolol increases plasma B-type cardiac natriuretic peptides in mild, stable heart failure

BACKGROUND

The effect of beta-blockade on the cardiac natriuretic peptides is poorly understood but could contribute to their beneficial treatment effect and may be relevant to clinical use of plasma brain natriuretic peptide (BNP)/N-terminal pro brain natriuretic peptide (NTproBNP) measurements in risk stratification and in titration of anti-heart failure therapy.

METHODS AND RESULTS

Sixteen men with mild, stable heart failure (NYHA class II to III; left ventricular ejection fraction <40%) underwent serial blood sampling for plasma natriuretic peptide levels and received infusions of atrial natriuretic peptide (ANP) and BNP before and 6 weeks after the introduction and uptitration of metoprolol or 6 weeks unchanged therapy in a randomized, parallel-group design. Plasma natriuretic peptides (BNP, NTproBNP, ANP, and NTproANP) were increased by metoprolol (P<0.01 for all). The natriuretic responses to ANP and BNP infusions were sustained with the introduction of metoprolol despite reduced renal perfusion pressure. The levels of the noninfused natriuretic peptide were increased by both ANP and BNP infusions, and this effect was enhanced by metoprolol. The early plasma half-life (t(1/2)alpha) of BNP was prolonged by metoprolol (5.6+/-0.45 to 11+/-1.3 versus 5.7+/-0.8 to 6.6+/-1.3 minutes in control subjects; P=0.019).

CONCLUSIONS

Plasma cardiac natriuretic peptide levels increase significantly with the introduction of metoprolol in heart failure as a result of effects on secretion and clearance. Natriuretic responses to NP infusions are sustained with beta-blockade despite reduced renal perfusion pressure. Clinicians should be aware that the introduction of metoprolol causes a rise in plasma BNP/NTproBNP that is unrelated to deterioration in clinical status and must be considered when measurements are undertaken for risk stratification or titration of treatment.

Utility of brain natriuretic peptide (BNP) measurement in cardiovascular disease

Cardiac failure is a prevalent and costly condition in Western society. The ageing of the population, together with current medical options which improve, rather than eradicate heart failure, lead to the projection that this problem will increase substantially in the foreseeable future. The availability of a simple test to assist the diagnosis and effective management of heart failure would greatly assist the clinical approach to this problem. This review examines the physiological basis for the measurement of natriuretic peptides as markers of the presence or risk of heart failure. It considers its use in the hospital and non-hospital setting and examines the cost-effectiveness of current assays. It is possible that in future natriuretic peptides may offer a form of treatment for heart failure, but this is beyond the scope of this review. Nevertheless, the review highlights the potential benefits of this group of tests in the management of heart failure.

Neuro-hormonal activation predicts ventilatory response to exercise and functional capacity in patients with heart failure

BACKGROUND

Heart failure (HF) is characterised by reduced tolerance to effort, associated with progressive fatigue and dyspnoea. Neuro-hormonal activation is a hallmark of HF and influences its clinical evolution.

AIM

To evaluate the relationship between neuro-hormonal activation, exercise capacity and ventilatory efficiency.

METHODS AND RESULTS

154 HF patients (127 males, 62 +/- 1 years) underwent cardiopulmonary exercise testing and resting blood sampling for assay of plasma brain natriuretic peptide (BNP), NT-proBNP, norepinephrine, epinephrine, aldosterone and plasma renin activity (PRA). BNP and NT-proBNP levels correlated with peak oxygen consumption (VO2) (both R = -0.53, p < 0.001), VE/VCO2 slope (R = 0.56; p < 0.001 and R = 0.58; p < 0.001, respectively) and maximum workload (R = -0.49; p < 0.001 and R = -0.47; p < 0.001, respectively). Norepinephrine correlated slightly less with peak VO2 (R = -0.38, p < 0.001), VE/VCO2 (R = 0.45; p < 0.001) and maximum workload (R = -0.35; p < 0.001). There was a significant inverse correlation between left ventricular ejection fraction and BNP (R = -0.48, p < 0.001), NT-proBNP (R = -0.42; p < 0.001) and norepinephrine (R = -0.43; p < 0.001). Weaker correlations were found for PRA, exercise parameters and ejection fraction. ROC curves showed that BNP was able to identify patients with peak VO2 < 14 ml/min/kg (cut-off 98 pg/ml, AUC 0.775) and a VE/VCO2 > 35 (cut-off 183 pg/ml, AUC 0.797), as well as NT-proBNP (cut-off 537 pg/ml, AUC 0.799 and cut-off 1010 pg/ml, AUC 0.768, respectively) and norepinephrine (cut-off 454 pg/ml, AUC 0.716 and cut-off 575 pg/ml, AUC 0.783, respectively).

CONCLUSION

Haemodynamic impairment (as indicated by BNP and NT-proBNP plasma values) and sympathetic activation predict exercise capacity and ventilatory efficiency in HF patients.

Brain natriuretic peptide and optimal management of heart failure

Aside from the important role of brain natriuretic peptide (BNP) in diagnosis, and differential diagnosis of heart failure, this biological peptide has proved to be an independent surrogate marker of rehospitalization and death of the fatal disease. Several randomized clinical trials demonstrated that drugs such as beta blocker, angiotensin converting enzyme inhibitor, spironolactone and amiodarone have beneficial effects in decreasing circulating BNP level during the management of chronic heart failure. The optimization of clinical decision-making appeals for a representative surrogate marker for heart failure prognosis. The serial point-of-care assessments of BNP concentration provide a therapeutic goal of clinical multi-therapy and an objective guidance for optimal treatment of heart failure. Nevertheless new questions and problems in this area remain to be clarified. On the basis of current research advances, this article gives an overview of BNP peptide and its property and role in the management of heart failure.

Right heart overload contributes to cardiac natriuretic hormone elevation in patients with heart failure

BACKGROUND

Atrial and brain natriuretic peptides (ANP and BNP) plasma concentration increases and holds a prognostic significance in patients with left ventricular dysfunction. We assessed the hypothesis that right ventricular (RV) overload might significantly contribute to plasma elevation of cardiac natriuretic hormones in patients with heart failure.

METHODS

Forty-one patients with cardiomyopathy and depressed left ventricular (LV) function (ejection fraction, EF, <40%), underwent cardiac magnetic resonance imaging (MRI) and resting plasma determination of ANP and BNP. Nineteen healthy subjects were also studied as control group. Ventricular volumes and function were assessed by MRI.

RESULTS

In the group of patients, LVEF was 22.6+/-1.2% (controls: 61.2+/-1.3%, P<0.001, mean+/-S.E.M.), while RVEF was 48.2+/-2.5% (controls: 66.7+/-1.6%, P<0.001); LV and RV end diastolic/systolic volumes, corrected by body surface area, were 143+/-7/114+/-7 ml/m2 (controls 70+/-3/27+/-2 ml/m2, both P<0.001) and 66+/-3/37+/-4 ml/m2 (controls: 63+/-4/21+/-2 ml/m2, P<0.01 only for end-systolic volume). BNP plasma value was on average 324+/-39 pg/ml (range: 23-1280, controls 10+/-2 pg/ml), ANP value was 144+/-17 pg/ml (range: 26-534, controls 15+/-1 pg/ml). BNP positively correlated with either end-diastolic or end-systolic RV volume in patients, less with LV systolic, and not with LV diastolic volume. Moreover, a significant negative correlation was observed between BNP and either LVEF or RVEF. Conversely, ANP showed a significant correlation only with end-systolic RV volume and with both RVEF and LVEF. When multivariate stepwise linear regression analysis was applied LVEF resulted the only independent predictor for ANP plasma values (R=0.591, P<0.001), while LVEF and RV end-diastolic volume for BNP (R=0.881, P<0.001, and R=0.881, P=0.035, respectively).

CONCLUSIONS

Right heart overload contributes independently to plasma elevation of natriuretic peptides. RV involvement, which is known to independently worsen prognosis in patients with cardiomyopathy, might contribute to their established prognostic power, inducing compensatory secretion of plasma cardiac natriuretic hormones.

Brain natriuretic peptide response is heterogeneous during β-blocker therapy for congestive heart failure

BACKGROUND

Plasma brain natriuretic peptide (BNP) levels are useful marker to guide medical treatment in patients with congestive heart failure (CHF). We tested the hypothesis that the plasma BNP concentration would be a useful marker of beta-blocker therapy for CHF.

METHODS AND RESULTS

Eighty-four patients with New York Heart Association class II-IV CHF and a left ventricular ejection fraction (LVEF) <40% were treated with beta-blockers, including metoprolol and carvedilol, for at least 16 weeks. End-diastolic and end-systolic dimensions decreased, and radionuclide LVEF increased 4 weeks after introduction of beta-blockers (early phase). LV end-diastolic and end-systolic dimensions both decreased, and LVEF increased 16 to 48 weeks after the therapy (late phase). However, the BNP concentration did not change during the observation period. Overall LV function improved in all 4 subgroups divided according to the baseline BNP levels.

CONCLUSIONS

Plasma BNP concentration is not a sensitive marker of successful beta-blocker therapy for CHF.

Exercise release of cardiac natriuretic peptides is markedly enhanced when patients with coronary artery disease are treated medically by beta-blockers

OBJECTIVES

This study sought to identify determinants of the exercise rise in plasma levels of cardiac natriuretic peptides (NPs) in patients with coronary artery disease (CAD).

BACKGROUND

During stress, there is a variable rise in the plasma level of NPs, but this rise frequently reaches levels that are known to lower the cardiac load and that thus might be beneficial to CAD patients.

METHODS

Plasma venous concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were determined at rest and peak exercise in 104 patients with chronic CAD who were referred to exercise thallium-201 ((201)Tl) single-photon emission computed tomography (SPECT) and radionuclide angiography.

RESULTS

The extent of scarred myocardium by (201)Tl-SPECT and patient age were the best independent predictors of NP concentrations at rest, but also of increases in NP concentration during exercise (all p < 0.001). Moreover, beta-blocking treatment was an additional and strong independent predictor of the increase in NP concentrations at exercise (p < 0.001 for ANP; p = 0.001 for BNP). On average, exercise increases in NP concentrations were more than twice as high in patients with (n = 55) than in those without (n = 49) beta-blocker treatment (ANP: +49 +/- 63 vs. +22 +/- 25 ng/l, p = 0.01; BNP: +24 +/- 5 vs. +11 +/- 15 ng/l, p = 0.04), whereas NP concentrations at rest were equivalent in the two groups (ANP: 34 +/- 34 vs. 30 +/- 33 ng/l, p = NS; BNP: 85 +/- 152 vs. 57 +/- 101 ng/l, p = NS).

CONCLUSIONS

Patients with chronic CAD exhibit much higher exercise releases of ANP and BNP when they are treated with beta-blockers. This enhanced secretion of potent vasodilating and natriuretic agents constitutes an original therapeutic mechanism for further protecting diseased hearts against stress.

Brain Natriuretic Peptide in the Management of Heart Failure

Brain natriuretic peptide (BNP), also called B-type natriuretic peptide, is a member of a family of structurally related hormones, the natriuretic peptides. Current data suggest that measurement of BNP plasma concentrations is a useful tool in the diagnosis of acute heart failure in patients presenting to an emergency department with acute dyspnea. Furthermore, BNP constitutes a promising new marker of prognosis after an acute coronary syndrome episode and in patients with chronic heart failure. Nesiritide, the human recombinant form of BNP, is a new vasodilator used in the treatment of acute heart failure that has several potential advantages over current drug therapy.

Cardiac natriuretic hormones, neuro-hormones, thyroid hormones and cytokines in normal subjects and patients with heart failure

The derangement of neuro-endocrine control of circulation influences both disease evolution and response to treatment in patients with heart failure, but little data are available about the complex relationships between the degree of neuro-hormonal activation and clinical severity. We studied the relationships between cardiac natriuretic hormones (CNHs) and several neuro-hormones and immunological markers in a prospective cohort of 105 consecutive patients with cardiomyopathy (77 men and 28 women, mean age 66.7±12.4 years, range 33–89 years). We assayed the circulating levels of CNHs (atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP)), plasma renin activity (PRA), aldosterone, cortisol, adrenaline, noradrenaline, thyroid hormones and thyroid stimulating hormone (TSH), tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The concentrations of all CNHs and neuro-hormones were higher in patients with heart failure compared to normal subjects, except for free triiodothyronine (FT3), which was below normal values. ANP was positively related to NYHA class, IL-6, adrenaline, noradrenaline and cortisol, while negatively with ejection fraction and FT3. BNP was positively related to age, NYHA class, IL-6, TNF-α, adrenaline, noradrenaline and cortisol, while negatively with ejection fraction and FT3. A stepwise multiple linear regression indicated that plasma ANP depended only on ejection fraction, adrenaline and noradrenaline values, while for plasma BNP variation NYHA class contributed too. Our data confirm a progressive activation of hormonal and immunological systems in patients with heart failure. Furthermore, CNH circulating levels in heart failure are affected not only by cardiac function and disease severity, but also by activation of neuro-hormonal and stress-related cytokine systems, as well as by the thyroid hormones, even on usual medical treatment.

Diagnostic accuracy and prognostic relevance of the measurement of cardiac natriuretic peptides: a review

BACKGROUND

The pathophysiologic and clinical relevance of cardiac natriuretic hormone (CNH) assays has been investigated in numerous experimental and clinical studies. Authors have sought to evaluate the diagnostic accuracy and prognostic relevance of the measurement of CNHs according to evidence-based laboratory medicine principles.

METHODS

In June 2003, we ran a computerized literature search on National Library of Medicine using keywords "ANP" and "BNP" and found more than 12 300 and 1200 articles, respectively. A more refined search with keywords "ANP or BNP assay" extracted approximately 7000 and 800 articles, respectively. Only studies specifically designed to evaluate the diagnostic accuracy and prognostic relevance of CNH measurements were selected from this huge mass of articles to be discussed in this review.

CONTENT

Several studies suggested that CNH assays may be clinically useful for the screening and classification of patients with heart failure, as a prognostic marker in cardiovascular disease, in the follow-up of patients with heart failure, and because they may reduce the need for further cardiac investigation. However, it is difficult to compare even the best-designed studies because not only did the authors evaluate different populations, they also used different gold standards.

CONCLUSIONS

CNH assays and conventional diagnostic work-ups provide complementary information for evaluation of the presence and severity of cardiac dysfunction and clinical disease. Several aspects of CNH assays are still to be elucidated, and further work is needed to carefully assess their diagnostic accuracy and prognostic value in cardiac disease.

Outpatient management of heart failure

With the increasing prevalence of heart failure, the greater spectrum of proven therapies, the broader spectrum of cardiac dysfunction qualifying for treatment and the recognition that heart failure is difficult to diagnose, the need for an indicator of both the diagnosis and the efficacy of treatment in this condition is clear. Plasma concentrations of the B-type natriuretic peptides are related to cardiac function and cardiovascular prognosis. They parallel hemodynamic indicators of cardiac dysfunction and may therefore act as indicators of the adequacy of therapy. In the one published trial of outpatient treatment of heart failure guided by plasma BNP, 69 patients (LVEF < 40%, NYHA II-IV) were randomised to treatment according to plasma peptide levels or a clinical score. The primary end point of total cardiovascular events was reduced in BNP-guided patients (19 versus 54 events) with p < 0.001 in a multivariate analysis. The natriuretic peptides and particularly plasma BNP and aminoterminal proBNP promised to provide an objective guide for optimising treatment in heart failure.

The use of brain natriuretic peptide as a screening test for left ventricular systolic dysfunction- cost-effectiveness in relation to open access echocardiography

BACKGROUND

Heart failure due to left ventricular systolic dysfunction (LVSD) has a high prevalence in the adult population but is difficult to diagnose accurately on clinical grounds in the community. Early diagnosis is important as effective treatments are available to reduce morbidity and mortality. Echocardiography is widely used to assess heart failure; however, this technology is relatively expensive and of limited availability. A potential diagnostic aid in primary care is the measurement of plasma brain natriuretic peptide (BNP).

OBJECTIVE

This study was performed to assess the value of BNP measurement as a selective pre-screen for breathless patients referred for open access echocardiography.

METHODS

BNP was measured by radioimmunoassay with prior extraction in 83 breathless subjects (age range 37-87 years, mean 72). Standard echocardiography was performed and left ventricular systolic function was assessed.

RESULTS

The prevalence of LVSD was 31% in this group. At cut-off values chosen to give negative predictive values for LVSD of >98% (BNP = 19 pg/ml), the sensitivity, specificity and positive predictive value for BNP were 100, 49.1 and 46.9%. Using this BNP threshold as a pre-screen for echocardiography would make a net saving of pound 964.20 without compromising the diagnostic accuracy.

CONCLUSION

BNP measurement appears to have a significant cost-effective benefit for the selection of patients for echocardiography.

B-type natriuretic peptide in cardiovascular disease

Natriuretic peptide hormones, a family of vasoactive peptides with many favourable physiological properties, have emerged as important candidates for development of diagnostic tools and therapeutic agents in cardiovascular disease. The rapid incorporation into clinical practice of bioassays to measure natriuretic peptide concentrations, and drugs that augment the biological actions of this system, show the potential for translational research to improve patient care. Here, we focus on the physiology of the natriuretic peptide system, measurement of circulating concentrations of B-type natriuretic peptide (BNP) and the N-terminal fragment of its prohormone (N-terminal BNP) to diagnose heart failure and left ventricular dysfunction, measurement of BNP and N-terminal BNP to assess prognosis in patients with cardiac abnormalities, and use of recombinant human BNP (nesiritide) and vasopeptidase inhibitors to treat heart failure.

Cardiac hormones as diagnostic tools in heart failure

In patients with heart failure, plasma levels of atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and the N-terminal fragments of their prohormones (N-ANP and N-BNP) are elevated, because the cardiac hormonal system is activated by increased wall stretch due to increased volume and pressure overload. Patients suspected of having heart failure can be selected for further investigations on the basis of having an elevated plasma concentration of N-ANP, BNP, and N-BNP. High levels of cardiac hormones identify those at greatest risk for future serious cardiovascular events. Moreover, adjusting heart failure treatment to reduce plasma levels of N-BNP may improve outcome. Cardiac hormones are most useful clinically as a rule-out test. In acutely symptomatic patients, a very high negative predictive value is coupled with a relatively high positive predictive value. Measurement of cardiac hormones in patients with heart failure may reduce the need for hospitalizations and for more expensive investigations such as echocardiography. However, there have also been conflicting reports on the diagnostic value of cardiac hormones, they are not specific for any disease, and the magnitude of the effects of age and gender on BNP in the normal subgroup suggests that these parameters need to be considered when interpreting cardiac hormone levels.

Role of brain natriuretic peptide in the diagnosis and management of heart failure: current concepts

BACKGROUND

Progression of heart failure is related to ventricular remodeling, a process associated to neurohormonal activation. Brain natriuretic peptide (BNP), a member of the natriuretic peptide family, has recently emerged as an important neurohormone in the pathophysiology of heart failure.

METHODS

In this update, some of the recent advances on the role of BNP in heart failure are summarized. In particular, the role of BNP in diagnosis of heart disease, as a prognostic marker of cardiovascular events and as a possible guide to optimize heart failure therapy is discussed.

RESULTS

Recent results from 4,300 patients enrolled in the Valsartan Heart Failure Trial (Val-HeFT) confirmed that BNP is the strongest predictor of outcome in heart failure, when compared to other neurohormones and clinical markers. The current use of BNP in the screening and diagnosis of heart failure and its possible future roles are presented.

CONCLUSION

In recent years, there has been an impressive accumulation of data supporting an important role of BNP as a diagnostic and prognostic marker of heart failure. Development of rapid, accurate and affordable diagnostic methods will allow the routine monitoring of BNP in a wide spectrum of settings, from general practice to controlled clinical trials.

Atenolol improves ventricular function without changing plasma noradrenaline but decreasing plasma atrial natriuretic factor in chronic heart failure

1 There is good evidence that beta-blockers improve ventricular function, disease progression and survival in patients with left ventricular systolic dysfunction. The aim of this study was to determine the effects of atenolol therapy on the sympathetic nervous system at rest and after ergometric exercise, on left ventricular function and on baseline plasma atrial natriuretic factor (ANF) in ambulatory patients with chronic heart failure (CHF). 2 Twenty-two patients [left ventricular ejection fraction (LVEF) <36%; New York Heart Association II-III] were studied before atenolol treatment. Because of cardiac events (new Hospital admission or death) only 13 patients completed 1 year of treatment. Baseline noradrenaline (NE) concentrations were similar in patients and controls while ANF was higher in patients than in controls (328 +/- 35 pg ml(-1) vs. 37 +/- 3 pg ml(-1); P<0.01). 3 Patients with events showed higher NE (540 +/- 87 pg ml(-1) vs. 303 +/- 44 pg ml(-1); P<0.01) and ANF (460 +/- 70 pg ml(-1) vs. 291 +/- 44 pg ml(-1); P<0.03) at rest; and greater NE response to exercise (2.003 +/- 525 pg ml(-1) vs. 694 +/- 121 pg ml(-1); P<0.005). Atenolol treatment improved LVEF (19.5 +/- 1.9% vs. 33 +/- 3.9%; P<0.001), increased exercise tolerance (9 +/- 3.2 min vs. 17 +/- 4.8 min; P<0.001) and decreased plasma ANF (292 +/- 42 pg ml(-1) vs. 133 +/- 35 pg ml(-1); P<0.01). 4 Reduced basal dihydroxyphenylglycol (DHPG)/NE ratio (3.4 +/- 0.46 vs. 4.3 +/- 0.35; P<0.01) was observed in patients compared with healthy volunteers. Atenolol increased DHPG plasma levels (1.398 +/- 129 pg ml(-1) vs. 913 +/- 86 pg ml(-1); P<0.005) but the DHPG/NE ratio during exercise was not modified after treatment, suggesting that re-uptake of released NE is not changed by beta-blocker treatment. 5 In conclusion, the fact that atenolol treatment improves ventricular dysfunction and clinical status without changing plasma NE levels in CHF patients, suggests that plasma NE is a poor surrogate measurement for cardiac sympathetic activity in this pathology. In addition, decrease in plasma ANF produced by atenolol treatment may reflect the improvement of ventricular function.

BNP in hormone-guided treatment of heart failure

The pharmacotherapy of heart failure has become complex. Angiotensin-converting enzyme inhibitors (or angiotensin II receptor blockers), beta-blockers, spironolactone, diuretics and digoxin can be prescribed concurrently. Endothelin antagonists and combined inhibitors of converting enzyme and neutral endopeptidase are under investigation. Optimal dosing will become increasingly difficult to judge. Plasma brain natriuretic peptide (BNP) indicates the severity of left ventricular dysfunction. The C-terminal bioactive peptide and N-terminal BNP (N-BNP) circulate at concentrations related to cardiac status. We proposed that plasma levels of N-BNP would provide an index to guide drug treatment in established heart failure. Sixty-nine patients were randomized to treatment adjusted according to clinical criteria or plasma N-BNP. Hormone-guided therapy resulted in fewer clinical end points than did clinical management. This encourages further exploration of hormone guidance of anti-heart failure therapy, which could be extended to patients with preserved ejection fraction, in addition to those with established systolic dysfunction.

Neurohormonal activation in heart failure after acute myocardial infarction treated with beta-receptor antagonists

BACKGROUND

Few studies have described how neurohormonal activation is influenced by treatment with beta-receptor antagonists in patients with heart failure after acute myocardial infarction. The aims were to describe neurohormonal activity in relation to other variables and to investigate treatment effects of a beta(1) receptor-antagonist compared to a partial beta(1) receptor-agonist.

METHODS

Double-blind, randomized comparison of metoprolol 50-100 mg b.i.d. (n=74), and xamoterol 100-200 mg b.i.d (n=67). Catecholamines, neuropeptide Y-like immunoreactivity (NPY-LI), renin activity, and N-terminal pro-atrial natriuretic factor (N-ANF) were measured in venous plasma before discharge and after 3 months. Clinical and echocardiographic variables were assessed.

RESULTS

N-ANF showed the closest correlations to clinical and echocardiographic measures of heart failure severity, e.g. NYHA functional class, furosemide dose, exercise tolerance, systolic and diastolic function. Plasma norepinephrine, dopamine and renin activity decreased after 3 months on both treatments, in contrast to a small increase in NPY-LI which was greater (by 3.9 pmol/l, 95% CI 1.2-6.6) in the metoprolol group. N-ANF increased on metoprolol, and decreased on xamoterol (difference: 408 pmol/l, 95% CI 209-607). Increase above median of NPY-LI (>25.2 pmol/l, odds ratio 2.8, P=0.0050) and N-ANF (>1043 pmol/l, odds ratio 2.8, P=0.0055) were related to long term (mean follow-up 6.8 years) cardiovascular mortality.

CONCLUSIONS

Decreased neurohormonal activity, reflecting both the sympathetic nervous system and the renin-angiotensin system, was found 3 months after an acute myocardial infarction with heart failure treated with beta-receptor antagonists. The small increase in NPY-LI may suggest increased sympathetic activity or reduced clearance from plasma. The observed changes of N-ANF may be explained by changes in cardiac preload, renal function, and differences in beta-receptor mediated inhibition of atrial release of N-ANF. NPY-LI, and N-ANF at discharge were related to long term cardiovascular mortality.

[Brain natriuretic peptide. Diagnostic value in heart failure]

BACKGROUND

Nowadays a number of diverse biochemical markers have been identified in patients with heart failure (HF) that could indicate the severity of the patients' illness. Among them, probably the most useful is brain natriuretic peptide (BNP) because it is easily obtained and because of its diagnostic and prognostic information. Our objective was to assess the association between BNP and other different associated variables previously known to be related to the evolution of HF, as well as its utility to distinguish systolic from diastolic HF.

PATIENTS AND METHOD

We studied 114 patients admitted consecutively for symptomatic HF for all causes (age: 66 years, male: 60%). In all patients plasma BNP was measured, from the third day of admission, with a specific radioinmunoassay. Echocardiography was performed in 101 patients.

RESULTS

BNP plasma levels increased in proportion to functional class (p = 0.01) and the degree of left ventricular dysfunction (p = 0.0001, r = 0.44). There was also an association between BNP and male sex (p = 0.008), higher plasmatic creatinine (p = 0.01, r = 0.25), Iarger ventricular diameters (p = 0.0001) and higher pulmonary systolic pressure (p = 0.001, r = 0.44). In the multivariate analysis, BNP was independently related to the rest of variables with left systolic ventricular function (p = 0.0001). Despite this association, we did not find a satisfactory cut-off value in BNP, with a good sensitivity and specificity value from the total number of patients, of which specifically systolic dysfunction as a cause of HF was detected.

CONCLUSIONS

a) BNP increases proportionately to the left ventricular dysfunction and HF severity, and b) BNP is not a useful tool to distinguish systolic from diastolic HF.

Brain natriuretic peptide-guided therapy for heart failure

The drug treatment of heart failure, once simple, has become complex. Apart from a loop diuretic and digoxin, most patients should now be receiving an angiotensin-converting enzyme inhibitor (or angiotensin II receptor blocker), a beta-blocker and spironolactone. Newer drugs, such as endothelin-receptor antagonists and combined blockers of converting-enzyme and neutral endopeptidase, might soon become available. When to introduce these drugs and what dose is optimal for any individual, are questions that currently vex clinicians. We proposed that plasma levels of the cardiac hormone brain natriuretic peptide (BNP, or better, its 1-76 amino-acid N-terminal fragment, N-BNP), would provide an objective index for guiding drug treatment in patients with established, stable cardiac failure. In a pilot study, 69 patients were randomized to drug treatment based on clinical criteria, or based on plasma levels of N-BNP. After a median follow-up of 9.6 months, those in the N-BNP group had fewer clinical end-points than those in the group managed by clinical criteria alone (19 vs 54; P= 0.02). These preliminary data encourage the concept that the increasingly complex pharmacotherapy for heart failure, both chronic (as in this trial) and acute, might best be guided by an objective measure such as plasma levels of BNP or N-BNP.

Plasma brain natriuretic peptide as a novel therapeutic indicator in idiopathic dilated cardiomyopathy during beta-blocker therapy: a potential of hormone-guided treatment

BACKGROUND

Plasma brain natriuretic peptide (BNP) is a sensitive and specific marker of left ventricular (LV) function. In the treatment of heart failure, especially in idiopathic dilated cardiomyopathy (IDC), beta-blocker (BB) therapy has been established as a powerful strategy. The purpose of this study was to analyze relationships between changes in BNP level and LV function during BB therapy in patients with IDC.

METHODS

In 30 patients with IDC who had already received conventional therapy, measurement for plasma BNP and norepinephrine levels and echocardiographic indices were evaluated before and 2 and 6 months after carvedilol in 21 patients and at baseline and after 6 months in 9 patients who did not receive carvedilol.

RESULTS

After 6 months carvedilol treatment significantly improved LV end-diastolic dimension (LVEDD) (65 +/- 8 to 61 +/- 8 mm) and LV ejection fraction (LVEF) (34% +/- 13% to 43% +/- 12%) with intergroup differences; it significantly decreased BNP (127 +/- 113 to 69 +/- 92 pg/mL) with no intergroup difference; however, it did not decrease norepinephrine. BNP correlated strongly with LVEDD, LVEF, and LV mass index in carvedilol-treated patients. The degree of change in BNP correlated with that in LVEDD or LVEF 6 months after carvedilol. All 14 patients with decreased or unchanged BNP levels showed an increase in LVEF, and 4 of 7 with a rise in BNP had decreased or unchanged LVEF. According to receiver operating characteristic analysis, the optimal BNP levels for detecting LVEF <35% before and after carvedilol were 75.5 and 69 pg/mL, respectively.

CONCLUSION

Plasma BNP levels may accurately reflect alteration in LV function and structure and can be used as a therapeutic indicator for risk stratification in patients with IDC during BB therapy.

Pharmacological effects of an aldehyde type alpha/beta-adrenoceptor blocking agent with vasodilating properties

KMUP 880723 (0.5, 1.0, and 3.0 mg/kg, iv) produced dose-dependent hypotensive and bradycardia responses in pentobarbital-anesthetized Wistar rats. KMUP 880723 (1.0 mg/kg, iv) also markedly inhibited both the tachycardia effects induced by (-)isoproterenol and arterial pressor responses induced by phenylephrine. In the isolated Wistar rat right atria, left atria, and guinea pig tracheal strips, KMUP 880723 competitively antagonized the (-)isoproterenol-induced positive chronotropic effects, inotropic effects, and tracheal relaxation effects in a concentration-dependent manner. The parallel shift to the right of the concentration-response curve of (-)isoproterenol suggested that KMUP 880723 was a beta(1)/beta(2)-adrenoceptor competitive antagonist. The apparent pA(2) values were 6.89+/-0.10 in the right atria, 7.02+/-0.09 in the left atria, and 6.59+/-0.11 in the trachea, indicating that KMUP 880723 was a nonselective beta-adrenoceptor blocker. In thoracic aorta experiments, KMUP 880723 also produced a competitive antagonism of norepinephrine-induced contraction with a pA(2) value of 7.14+/-0.06. In isolated rat thoracic aorta, KMUP 880723 more potently relaxed the contractions induced by norepinephrine (3 x 10(-6) M) than those by high K(+) (75 mM). In the radioligand-binding assay, the pK(i) values of [3H]CGP-12177 binding to rat ventricle and lung membranes were 6.56 and 6.40, respectively, and the value of [3H]prazosin binding to rat brain membranes was 6.66. These results further confirmed the alpha/beta-adrenoceptor blocking activities of KMUP 880723 reported in the functional studies. We conclude that KMUP 880723 is a nonselective beta-adrenoceptor antagonist with alpha-adrenoceptor blocking-associated vasorelaxant activity.

Eugenodilol: a third-generation beta-adrenoceptor blocker, derived from eugenol, with alpha-adrenoceptor blocking and beta2-adrenoceptor agonist-associated vasorelaxant activities

Eugenodilol, derived from natural eugenol, was first investigated with in vivo and in vitro models. In our in vivo study, eugenodilol (0.5, 1.0, and 1.5 mg/kg, i.v.) produced dose-dependent hypotensive and bradycardic responses in pentobarbital-anesthetized Wistar rats. Eugenodilol also inhibited the tachycardia and arterial pressor effects induced by (-)isoproterenol and phenylephrine, respectively. In our in vitro study, eugenodilol competitively antagonized (-)isoproterenol-induced positive inotropic and chronotropic effects and tracheal-relaxation responses on isolated guinea pig tissues in a concentration-dependent manner. The apparent pA2 values were 7.88+/-0.12 for right atria, 7.52+/-0.05 for left atria, and 7.33+/-0.15 for trachea, indicating that eugenodilol was a nonselective beta-adrenoceptor blocker. In thoracic aorta experiments, the apparent pA2 values of alpha-adrenoceptor blockade were 7.05+/-0.25 and 6.87+/-0.08 for eugenodilol and labetalol, respectively. In addition, eugenodilol produced cumulative relaxation responses on isolated guinea pig tracheal strips. The effects were competitively antagonized by ICI 118,551 (10(-8)-10(-6) M), a relatively selective beta2-adrenoceptor antagonist. In the radioligand-binding assay, the Ki values of [3H]CGP-12177 binding to rat ventricle and lung membranes were 9.72 and 48.29 nM, respectively, and the value of [3H]prazosin binding to rat brain membrane was 38.72 nM. These results further confirmed the alpha/beta-adrenoceptors-blocking activities of eugenodilol reported in the functional studies. We conclude that eugenodilol is a novel third-generation beta-adrenoceptor blocker with ancillary blocking activity at alpha-adrenoceptors and weak sympathomimetic activity at beta2-adrenoceptors.

Cohort study of plasma natriuretic peptides for identifying left ventricular systolic dysfunction in primary care

OBJECTIVES

To determine whether blood natriuretic peptide concentrations are helpful in identifying or excluding left ventricular systolic dysfunction in stable survivors of acute myocardial infarction.

DESIGN

Comparison of blood natriuretic peptide concentrations with echocardiographic assessment of left ventricular systolic function in a general practice population.

SETTING

Practices in Western District of Glasgow audit group.

SUBJECTS

134 long term survivors of myocardial infarction recalled for echocardiography as part of a primary care secondary prevention audit.

MAIN OUTCOME MEASURES

Area under the receiver operating curve for brain natriuretic peptide and N-terminal atrial natriuretic peptide.

RESULTS

Brain natriuretic peptide was of some diagnostic utility in identifying the minority of subjects with severe left ventricular dysfunction (area under curve=0.73) but was unable to discriminate between patients with moderately severe dysfunction and those with preserved left ventricular function (area under curve for moderate or severe dysfunction=0.54). The corresponding values for N-terminal atrial natriuretic peptide for severe and moderate or severe dysfunction were 0.55 and 0.56 respectively.

CONCLUSIONS

Blood natriuretic peptide concentrations are not useful in identifying important left ventricular systolic dysfunction in stable survivors of myocardial infarction.

Beta blockers in heart failure: a comparison of a vasodilating beta blocker with metoprolol

OBJECTIVE

To determine whether a third generation vasodilating beta blocker (celiprolol) has long term clinical advantages over metoprolol in patients with chronic heart failure.

DESIGN

A double blind placebo controlled randomised trial.

SETTING

University teaching Hospital.

PATIENTS

50 patients with stable chronic heart failure (NYHA class II-IV) due to idiopathic dilated, ischaemic, or hypertensive cardiomyopathy, with left ventricular ejection fraction < 0.45.

INTERVENTIONS

Celiprolol 200 mg daily (n = 21), metoprolol 50 mg twice daily (n = 19), or placebo (n = 10) for three months with a four week dose titration period. After the double blind period, patients entered an open label study (with placebo group receiving beta blockers) and were assessed after one year.

MAIN OUTCOME MEASURES

Clinical response, efficacy, and tolerance were assessed by the Minnesota heart failure symptom questionnaire six minute walk test, Doppler echocardiography (systolic and diastolic function), radionuclide ventriculography, and atrial and brain natriuretic peptides measured at baseline and after three months.

RESULTS

In the metoprolol group at 12 weeks v baseline there was a 47% reduction in symptom score (p < 0.001), improvement of NYHA class (mean (SEM), 2.6 (0.12) to 1.9 (0.13), p = 0.001), exercise distance (1246 (54) to 1402 (52) feet, p < 0.001), and left ventricular ejection fraction (26.9(3.1)% to 31(3.0)%, p = 0.016), and a fall in heart rate (resting, 79 (3) to 62 (3) beats/min, p < 0.001). In the celiprolol group there was a 38% reduction in symptom score (p = 0.02), less improvement in exercise distance (1191 (55) to 1256 (61) feet, p = 0.05), and no significant changes in NYHA class, left ventricular ejection fraction, or heart rate. Mortality at one year was 11% in metoprolol and 19% in the celiprolol group, and symptomatic improvement was maintained in the survivors.

CONCLUSIONS

Both drugs were well tolerated but the vasodilator properties of celiprolol do not seem to provide any obvious additional benefit in the long term treatment of heart failure.

Effect of beta-blockade on mortality in patients with heart failure: a meta-analysis of randomized clinical trials

OBJECTIVES

We sought to evaluate the current evidence for an effect of beta-blockade treatment on mortality in patients with congestive heart failure (CHF).

BACKGROUND

Although numerous small studies have suggested a benefit with beta-blocker therapy in patients with heart failure, a clear survival benefit has not been demonstrated. A recent combined analysis of several studies with the alpha- and beta-adrenergic blocking agent carvedilol demonstrated a significant survival advantage; however, the total number of events was small. Furthermore, it is unclear if previous studies with other beta-blockers are consistent with this finding.

METHODS

Randomized clinical trials of beta-blockade treatment in patients with CHF from January 1975 through February 1997 were identified using a MEDLINE search and a review of reports from scientific meetings. Studies were included if mortality was reported during 3 or more months of follow-up.

RESULTS

We identified 35 reports, 17 of which met the inclusion criteria. These studies included 3,039 patients with follow-up ranging from 3 months to 2 years. Beta-blockade was associated with a trend toward mortality reduction in 13 studies. When all 17 reports were combined, beta-blockade significantly reduced all-cause mortality (random effect odds ratio [OR] 0.69, 95% confidence interval [CI] 0.54 to 0.88). A trend toward greater treatment effect was noted for nonsudden cardiac death (OR 0.58, 95% CI 0.40 to 0.83) compared with sudden cardiac death (OR 0.84, 95% CI 0.59 to 1.2). Similar reductions in mortality were observed for patients with ischemic (OR 0.69, 95% CI 0.49 to 0.98) and nonischemic cardiomyopathy (OR 0.69, 95% CI 0.47 to 0.99). The survival benefit was greater for trials of the drug carvedilol (OR 0.54, 95% CI 0.36 to 0.81) than for noncarvedilol drugs (OR 0.82, 95% CI 0.60 to 1.12); however, the difference did not reach statistical significance (p = 0.10).

CONCLUSIONS

Pooled evidence suggests that beta-blockade reduces all-cause mortality in patients with CHF. Additional trials are required to determine whether carvedilol differs in its effect from other agents.

Validated assay for the determination of celiprolol in plasma using high-performance liquid chromatography and a silanol deactivated reversed-phase support

Previously reported methods for the determination of celiprolol in plasma could not be satisfactorily employed due to interference from plasma components. Thus, an improved, convenient and efficient method for the determination of the plasma concentration of celiprolol was developed using a simple solvent extraction step followed by high-performance liquid chromatography on a silanol deactivated C18 column with fluorescence detection. The plasma interference was resolved from celiprolol and the typical trailing of basic compounds on reversed-phase HPLC was eliminated. The peak-area ratio versus plasma concentration was linear over the range of 5-1000 ng/ml and the detection limit was 5 ng/ml.