BNP and congestive heart failure

Role of B-Type Natriuretic Peptide and Effect of Nesiritide After Total Cardiac Replacement With the AbioCor Total Artificial Heart

Endogenous B-type natriuretic peptide (BNP) is thought to be produced in the cardiac ventricles. After sub-total cardiectomy and implantation of a total artificial heart (TAH), the abrupt withdrawal of BNP impairs renal function despite normal hemodynamic variables. We hypothesized that abrupt withdrawal of endogenous BNP may impair renal function and volume homeostasis and BNP may have a direct renal influence unrelated to its cardiovascular effect. Nesiritide infusion should be supplemented in the interim and weaned slowly until BNP levels normalize, which suggests that BNP is produced in tissues other than the cardiac ventricles.

Nesiritide in a pediatric oncology patient with renal insufficiency and myocardial dysfunction following septic shock

Nesiritide is a recombinant formulation of B-type natriuretic peptide used most commonly in the treatment of adults with decompensated congestive heart failure. The physiologic effects of BNP include natriuresis, diuresis, and smooth muscle relaxation. These physiologic effects result in its beneficial therapeutic effects, including a decrease in afterload, resulting in increased cardiac output with improved peripheral perfusion. The authors report on a 17-year-old with acute myelogenous leukemia who was admitted to the Pediatric ICU for treatment of septic shock, respiratory failure, myocardial dysfunction, and renal insufficiency. After the initial stabilization of his hemodynamic status, nesiritide was started and resulted in a stable balance of fluid intake versus output without the use of diuretics, improvement in myocardial function, and recovery of renal function manifested by a decrease of blood urea nitrogen and creatinine back to baseline values. The end-organ effects of nesiritide, previous reports regarding its use in the pediatric population, and its potential applications in the ICU setting are discussed.

The diagnostic accuracy of plasma BNP and NTproBNP in patients referred from primary care with suspected heart failure: Results of the UK natriuretic peptide study

OBJECTIVES

To determine the diagnostic accuracy of the measurement of plasma B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NTproBNP) in patients referred by their general practitioners (GPs) with symptoms suggestive of heart failure. Additionally, to compare the diagnostic accuracy of the resting 12-lead electrocardiogram (ECG) with that of the peptides.

DESIGN

A diagnostic accuracy study.

SETTING

Rapid-access heart failure clinics in five hospitals.

PARTICIPANTS

306 patients referred by their GPs with suspected heart failure.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive and negative predictive values (PPV and NPV) and positive and negative likelihood ratios for BNP, NTproBNP and the ECG for the diagnosis of heart failure. Area under the receiver operating characteristics (ROC) curves for the two natriuretic peptides.

RESULTS

The diagnosis of heart failure was confirmed in 104 (34%) patients. The area under the ROC curve was 0.84 [95% CI 0.79-0.89] for BNP and 0.85 [0.81-0.90] for NTproBNP. At the manufacturers' recommended decision cut-points, NTproBNP provided a higher NPV (0.97) than BNP (0.87), but at lower PPV (0.44 versus 0.59). An abnormal ECG did not add any further predictive value to that of NTproBNP.

CONCLUSIONS

We have confirmed the value of the measurement of plasma BNP or NTproBNP as a 'rule-out' test for heart failure in patients currently referred by GPs to rapid access diagnostic clinics. A simple classification of the 12-lead ECG into 'normal' or 'abnormal' adds little value to ruling out heart failure in these circumstances. Further work is necessary to establish the best decision cut-points for use in clinical practice.

Natriuretic Peptides and Mortality After Stroke

Background and Purpose— Measurement of natriuretic peptides provides prognostic information in various patient populations. The prognostic value of natriuretic peptides among patients with acute stroke is not known, although elevated peptide levels have been observed.

Methods— A series of 51 patients (mean age, 68±11years) with first-ever ischemic stroke underwent a comprehensive clinical examination and measurements of plasma atrial natriuretic peptides (N-ANP) and brain natriuretic peptides (N-BNP) in the acute phase of stroke. The patients were followed-up for 44±21 months. Risk factors for all-cause mortality were assessed. Control populations, matched for gender and age, consisted of 51 patients with acute myocardial infarction (AMI) and 25 healthy subjects.

Results— Plasma concentrations of N-ANP (mean±SD, 988±993 pmol/L) and N-BNP (751±1608 pmol/L) in the stroke patients were at the same level as those in the AMI patients (NS for both), but significantly higher than those of the healthy subjects (358±103 pmol/L, P <0.001 and 54±26 pmol/L, P <0.01, respectively). Elevated levels of N-ANP and N-BNP predicted mortality after stroke (risk ratio [RR] 4.3, P <0.01 and RR 3.9, P <0.01, respectively) and after AMI ( P <0.05), and remained independent predictors of death after stroke even after adjustment for age, diabetes, coronary artery disease, and medication (RR 3.9, P <0.05 and RR 3.7, P <0.05, respectively).

Conclusion— Plasma levels of natriuretic peptides are elevated in the acute phase of stroke and predict poststroke mortality.

Brain natriuretic peptide levels do not correlate with acute cellular rejection in De Novo orthotopic heart transplant recipients

BACKGROUND

The changes in brain natriuretic peptide (BNP) levels after orthotopic heart transplantation have not been previously described. The use of brain natriuretic peptide levels as a surrogate marker for cellular rejection remains controversial, with conflicting data.

METHODS

We prospectively evaluated the potential utility of BNP levels in the first 6 months after transplantation and sought correlation with histologic grade of rejection and hemodynamic status.

RESULTS

Thirty-five patients and 265 biopsy samples were included in the study. BNP levels did not correlate with histologic grade of rejection. They showed good correlation with central venous pressure and pulmonary capillary wedge pressure. BNP levels were elevated after transplant and showed a steep time-dependent decline. BNP levels correlated with echocardiographically derived indices of diastolic dysfunction.

CONCLUSIONS

BNP levels are not a surrogate marker for rejection in the first 2 months after orthotopic heart transplantation and do not obviate the necessity for endomyocardial biopsy. Whether BNP levels have long-term prognostic significance is unclear and remains the subject of ongoing prospective study.

B-type natriuretic peptide levels are not a surrogate marker for invasive hemodynamics during management of patients with severe heart failure

BACKGROUND

We sought to assess the utility of serial BNP measurements in patients with severe heart failure and attempted to correlate values with invasively derived data.

METHODS

In a retrospective study, we analyzed serial BNP levels in patients receiving hemodynamically guided therapy for severe heart failure and sought correlation with invasively derived data.

RESULTS

Thirty-nine patients with New York Heart Association Class III-IV, with an ejection fraction of 35% or less, who had a pulmonary artery catheter inserted for hemodynamically tailored heart failure therapy, were identified and serial BNP measurements reviewed. BNP was estimated on admission, at 12 and 36 hours. Normally distributed variables are expressed as mean +/- SD and otherwise as median +/- interquartile range. Mean ejection fraction was 16% +/- 6%. Mean pulmonary artery occlusion pressures (PAOP) fell with therapy and were 25 +/- 7 mmHg, 18 +/- 7 mmHg and 19 +/- 7 mmHg at admission, 12 hours and 36 hours respectively ( P < 0.05). Median BNP levels fell from 1200 +/- 641 to 771 +/- 803 at 12 hours and to 805 +/- 771 at 36 hours (P < .001). There was no correlation between BNP and any hemodynamically derived variable. A change in BNP was not associated with a change in PAOP in any individual patient. Only 42% remained alive on medical therapy at 30 days.

CONCLUSIONS

In patients with severe heart failure, BNP levels do not accurately predict serial hemodynamic changes and do not obviate the need for pulmonary artery catheterization.

Nesiritide during extracorporeal membrane oxygenation

Nesiritide is a recombinant formulation of B-type natriuretic peptide (BNP). Preliminary experience in the adult population has shown nesiritide to be an effective agent in the treatment of decompensated congestive heart failure (CHF) in adults. Given its physiological effects, it may be an effective agent in other clinical scenarios. We report the use of nesiritide in two infants during extracorporeal membrane oxygenation (ECMO). In one patient, nesiritide in doses up to 0.09 microg.kg(-1).min(-1) were used to control mean arterial pressure while in the other patient, doses of 0.01-0.03 microg.kg(-1).min(-1) were used to augment urine output. The potential applications of nesiritide and dosing regimens for this agent in the ECMO population are discussed.

Ventricular hypertrophy increases NT-proBNP in subjects with and without hypertension

BACKGROUND

It has been published that hypertension (HT) must be taken into account when using NT-proBNP, but left ventricular (LV) hypertrophy without HT could be a cause of NT-proBNP elevation. In a population study we compared NT-proBNP in subjects with hypertrophy, with and without diagnosis of HT.

METHODS

We studied 215 subjects from a random sample of 432 people who had declared to suffer from dyspnea. These 432 subjects were referred to their hospital where blood samples were taken, an echo-Doppler study was performed and a specific questionnaire was completed. We got a positive answer from 215, and 52 (24%) have LV hypertrophy.

RESULTS

When we compared NT-proBNP in non-hypertrophic population, 148 +/- 286 pg/ml, with NT-proBNP in LV hypertrophic population, 202 +/- 209 pg/ml, we found P < 0.001. In the hypertrophic group, when we compared NT-proBNP (199 +/- 201 pg/ml) in normotensive subjects (LV mass index 170 +/- 70 g/m2, Vp 50 +/- 18 cm/s, LVEF 62 +/- 8) with NT-proBNP (205 +/- 220 pg/ml) in subjects with diagnosis of HT (LV mass index 169 +/- 37 g/m2, Vp 55 +/- 20 cm/s, LVEF 64 +/- 10), we found NS.

CONCLUSIONS

This population study shows that NT-proBNP is elevated in patients with LV hypertrophy with or without HT. In LV hypertrophy the presence of HT does not influence the peptide levels significantly.

Preliminary experience with nesiritide in the pediatric population

Nesiritide is a recombinant formulation of brain-type natriuretic factor. Preliminary experience in the adult population suggests that nesiritide may be an effective agent in the treatment of decompensated congestive heart failure. Given its physiologic effects, it may be an effective agent in the pediatric population; however, to date, there are no reports regarding its use in infants and children. The authors retrospectively review their experience with nesiritide in 5 pediatric patients. The cohort of 5 patients included a diverse population with 2 patients who were status postcardiothoracic surgery, 2 with adult respiratory distress syndrome, and 1 in the recovery phase from septic shock. Although no direct measurement of cardiac output was feasible as none of the patients had a pulmonary artery catheter, other indicators of increased cardiac output were noted. These included improved peripheral perfusion with warming of the extremities and improvement of peripheral pulses in all of the patients, increased venous saturation in 2 of the patients, and maintenance of or increased urine output despite weaning or discontinuation of diuretics. In 3 of the patients, nesiritide was started as the primary agent to provide a decrease in systemic vascular resistance and augment cardiac output, while in the other 2 patients, nesiritide was used when other vasoactive agents failed to provide the desired effect or resulted in adverse effects.

Is plasma N-BNP a good indicator of the functional reserve of failing hearts? The FRESH-BNP study

AIMS

Whether plasma N-terminal brain natriuretic peptide (N-BNP) is useful in the diagnosis of heart failure (HF) depends traditionally on whether it is as good as the putative 'gold-standard', left ventricular ejection fraction (LVEF), in indicating cardiac dysfunction. However, since HF is primarily an impairment of function of the cardiac pump, we explored the relationship between N-BNP and direct and indirect indicators of cardiac pump dysfunction.

METHODS AND RESULTS

Eighty-six HF patients (mean age 56 years) with a range of LVEF's (mean 36.9+/-15.2%, range 15-66%) and 10 age-matched healthy controls were recruited into the study and had resting N-BNP measured. Cardiopulmonary exercise testing was performed to assess peak oxygen consumption (Vo(2)). A subgroup of 23 subjects underwent further exercise haemodynamic assessment to evaluate peak cardiac power output (CPO). The CHF group had significantly higher N-BNP (median [interquartile range]) levels (299 [705] fmol/ml) than the control group (7 [51] fmol/ml, P<0.005). Significant correlations between N-BNP and peak Vo(2), and N-BNP and peak CPO were observed (R> or =0.5, P<0.005). Although significant correlation was observed between N-BNP and LVEF (R=0.34, P=0.01), the correlations between LVEF and peak Vo(2) or peak CPO (all R<0.3, P>0.3) were not significant. Multivariate analysis identified plasma N-BNP and NYHA class, but not LVEF, as independent predictors of peak Vo(2).

CONCLUSIONS

We have found that N-BNP was surprisingly good as a simple indicator of cardiac pump dysfunction. Since heart failure is an inadequacy of function, these results strongly support the notion that N-BNP is a useful blood test in estimating the extent of cardiac pump dysfunction and helpful in establishing positive diagnosis of heart failure.

Association of Elevated B-Type Natriuretic Peptide Levels With Angiographic Findings Among Patients With Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction

OBJECTIVES

We hypothesized that elevated B-type natriuretic peptide (BNP) levels would be associated with a greater severity of angiographic disease and a greater extent of myocardium at risk.

BACKGROUND

Elevations of BNP have been associated with increased risk of adverse outcomes in patients with unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI).

METHODS

Of the 2,220 patients with UA/NSTEMI enrolled in the Treat Angina with Aggrastat and Determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction-18 (TACTICS-TIMI-18) trial, 276 randomized to the invasive arm had both baseline BNP levels and angiographic core laboratory data. Patients were categorized according to their baseline BNP levels as < or =80 or >80 pg/ml.

RESULTS

A total of 233 patients (84%) had BNP levels >80 pg/ml, and 43 (16%) had admission BNP levels >80 pg/ml. Patients with BNP >80 pg/ml had tighter culprit vessel stenosis on quantitative coronary angiography (median stenosis 76% vs. 67%, p = 0.004) and a higher (slower) corrected TIMI frame count (median CTFC 43 vs. 30, p = 0.018) in the culprit vessel. The median BNP level was higher in patients with a left anterior descending coronary artery (LAD) versus non-LAD culprit lesion location (median BNP level 40 vs. 24 pg/ml, p = 0.005), and the culprit artery was more often the LAD in patients with BNP >80 pg/ml compared with < or =80 pg/ml (44% vs. 30%, p = 0.06).

CONCLUSIONS

Among patients with UA/NSTEMI, elevated BNP levels are associated with tighter culprit stenosis, higher CTFC, and LAD involvement. These findings suggest that elevated BNP may be associated with a greater severity and extent of myocardial ischemic territory during the index event and may partly explain the association between elevated BNP and adverse outcomes.

B type natriuretic peptide testing: where are we now?

It is possible that plasma BNP measurement might be to heart failure what glycated haemoglobin measurement is to diabetes mellitus. Indeed, within 12-24 months, BNP testing might become a routine addition to the monitoring of patients with heart failure. In the meantime its main role is in helping to rule out heart failure in patients with new symptoms

Urinary biopyrrins levels are elevated in relation to severity of heart failure

OBJECTIVES

We investigated the relationship between the urinary levels of biopyrrins and the severity of heart failure (HF).

BACKGROUND

Oxidative stress is evident in heart disease and contributes to the development of ventricular dysfunction in patients with HF. Biopyrrins, oxidative metabolites of bilirubin, have been discovered as potential markers of oxidative stress.

METHODS

We measured the levels of urinary biopyrrins and plasma B-type natriuretic peptide (BNP) in 94 patients with HF (59 men; mean age 65 years) and 47 control subjects (30 men; mean age 65 years). Urine and blood samples were taken after admission in all subjects. Further urine samples were obtained from 40 patients after treatment of HF.

RESULTS

The urinary biopyrrins/creatinine levels (micromol/g creatinine) were the highest in patients in New York Heart Association (NYHA) class III/IV (n = 26; 17.05 [range 7.85 to 42.91]). The urinary biopyrrins/creatinine levels in patients in NYHA class I (n = 35; 3.46 [range 2.60 to 5.42]) or II (n = 33; 5.39 [range 3.37 to 9.36]) were significantly higher than those in controls (2.38 [range 1.57 to 3.15]). There were significant differences in urinary biopyrrins/creatinine levels among each group. The treatment of HF significantly decreased both urinary biopyrrins/creatinine levels (from 7.43 [range 3.84 to 17.05] to 3.07 [range 2.21 to 5.71]) and NYHA class (from 2.5 +/- 0.1 to 1.7 +/- 0.1). Log biopyrrins/creatinine levels were positively correlated with log BNP levels (r = 0.650, p < 0.001).

CONCLUSIONS

These results indicate that urinary biopyrrins levels are increased in patients with HF and are elevated in proportion to its severity.

Methods of assessment of volume status and intercompartmental fluid shifts in hemodialysis patients: implications in clinical practice

Determining dry weight and assessing extracellular fluid volume in hemodialysis (HD) patients is one of the greatest challenges to practicing nephrologists. The clinical examination has limited accuracy, so different strategies have been investigated to aid in this evaluation. Biochemical markers of volume overload (ANP, BNP, cGMP) are fraught with excessive variability and poor correlation with volume status. Inferior vena cava ultrasound is effective, but cumbersome and costly. Bioimpedance measurements of intra- and extracellular water have significant shortcomings when used as isolated measurements, but can be useful in following trends over time and have been shown to improve intradialytic symptoms and blood pressure control. Continuous blood volume monitoring is helpful in preventing intradialytic hypotension and may help identify patients who are volume overloaded and need increased ultrafiltration. In this review we discuss these different techniques and other developments in the evaluation of dry weight and volume status, which may enhance our ability to improve patient stability and well-being during HD sessions.

Nesiritide therapy for acute heart failure

Each year, more than 1 million hospitalizations are the result of heart failure. Acute exacerbations of heart failure can occur following routine surgical procedures. One of the newest pharmacological therapies for heart failure is nesiritide. The PACU nurse's vital role in the early recognition and early intervention of heart failure may include the administration of this agent.

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.

Biochemical markers of cardiac diseases

This article reviews the current contribution of the determination of biochemical markers to clinical cardiology and discusses some important developments in this field. Biochemical markers play a pivotal role in the diagnosis and management of patients with acute coronary syndrome (ACS), as witnessed by the incorporation of cardiac troponins into new international guidelines for patients with ACS and in the redefinition of myocardial infarction. Despite the success of cardiac troponins, there is still a need for development of early markers that can reliably rule out ACS from the emergency room at presentation and detect myocardial ischemia also in the absence of irreversible myocyte injury. Under investigation are two classes of indicators: markers of early injury/ischemia and markers of coronary plaque instability and disruption. Finally, with the characterization of the cardiac natriuretic peptides, Laboratory Medicine is also assuming part in the assessment of cardiac function.

Epidemiology and clinical aspects of congestive heart failure

Congestive heart failure (CHF) is an increasing problem for healthcare systems in all developed countries. The prevalence is increasing partly due to ageing of the population, but also due to improved survival from acute cardiac disease such as myocardial infarction. Advances in diagnostic techniques and better understanding of the pathophysiology offer many opportunities for substantial improvement in the management of CHF. This article reviews the current epidemiology of CHF and the related diagnostic issues.

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.

Overexpression of a set of genes, including WISP-1, common to pulmonary metastases of both mouse D122 Lewis lung carcinoma and B16-F10.9 melanoma cell lines

Despite advances in the management of solid tumours, the development of metastases continues to be the most significant problem and cause of death for cancer patients. To define genetic determinants of pulmonary metastases, we have applied oligonucleotide microarrays to established murine models of highly metastatic D122 Lewis lung carcinoma and B16-F10.9 melanoma cell lines. These models are characterised by primary subcutaneous growth in C57BL/6J mice, a period of minimal residual disease and spontaneous pulmonary metastases. Microarray analysis defined seven genes, namely - arginase, brain natriuretic peptide (BNP), interleukin-1 alpha (IL-1 alpha), plasminogen activator inhibitor-2 (PAI-2), surfactant protein C (SP-C), uteroglobin (UG) and wnt-1-induced secreted protein-1 (WISP-1), which were consistently elevated in pulmonary metastases compared to the primary tumour of both D122 and B16-F10.9 models. Previous studies demonstrated that two of these seven genes, IL-1 alpha and PAI-2, are involved in the metastatic process. The results obtained by the microarrays were confirmed by real-time quantitative PCR, for three chosen genes - PAI-2, WISP-1 and UG. Our approach aimed to identify genes essential for the metastatic process in general and for pulmonary metastases specifically. Further research should address the precise role of these genes in the metastasising process to the lungs and test if they could be used as targets for future therapies.

Structural pathways and prevention of heart failure and sudden death

We review the macroscopic and microscopic anatomy of myocardial disease associated with heart failure (HF) and sudden cardiac death (SCD) and focus on the prevention of SCD in light of its structural pathways. Compared to patients without SCD, patients with SCD exhibit 5- to 6-fold increases in the risks of ventricular arrhythmias and SCD. Epidemiologically, left ventricular hypertrophy by ECG or echocardiography acts as a potent dose-dependent SCD predictor. Dyslipidemia, a coronary disease risk factor, independently predicts echocardiographic hypertrophy. In adult SCD autopsy studies, increases in heart weight and severe coronary disease are constant findings, whereas rates of acute coronary thrombi vary remarkably. The microscopic myocardial anatomy of SCD is incompletely defined but may include prevalent changes of advanced myocardial disease, including cardiomyocyte hypertrophy, cardiomyocyte apoptosis, fibroblast hyperplasia, diffuse and focal matrix protein accumulation, and recruitment of inflammatory cells. Hypertrophied cardiomyocytes express "fetospecific" genetic programs that can account for acquired long QT physiology with risk for polymorphic ventricular arrhythmias. Structural heart disease associated with HF and high SCD risk is causally related to an up-regulation of the adrenergic renin-angiotensin-aldosterone pathway. In outcome trials, suppression of this pathway with combinations of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, and mineralocorticoid receptor blockers have achieved substantial total mortality and SCD reductions. Contrarily, trials with ion channel-active agents that are not known to reduce structural heart disease have failed to reduce these risks. Device therapy effectively prevents SCD, but whether biventricular pacing-induced remodeling decreases left ventricular mass remains uncertain.

Increased cardiac BNP expression associated with myocardial ischemia

Congestive heart failure is accompanied by increased cardiac brain natriuretic peptide (BNP) gene expression with elevated plasma concentrations of BNP and its precursor, proBNP. We investigated if myocardial ischemia in the absence of overt heart failure may be another mechanism for increased myocardial BNP expression. The BNP expression was examined in hypoxic myocardium of patients undergoing coronary bypass grafting surgery, in patients with coronary artery disease and normal left ventricular function undergoing percutaneous transluminal intervention therapy, and in heart failure patients without coronary artery disease. BNP mRNA was quantified by real-time PCR, and plasma BNP and proBNP concentrations were measured with radioimmunoassays. Quantitative analysis of BNP mRNA in atrial and ventricular biopsies from coronary bypass grafting patients revealed close associations of plasma BNP and proBNP concentrations to ventricular, but not atrial, BNP mRNA levels. Plasma BNP and proBNP concentrations were markedly increased in patients with coronary artery disease but without concomitant left ventricular dysfunction. These results are compatible with the notion that myocardial ischemia, even in the absence of left ventricular dysfunction, augments cardiac BNP gene expression and increases plasma BNP and proBNP concentrations. Thus, elevated BNP and proBNP concentrations do not necessarily reflect heart failure but may also result from cardiac ischemia.

Prolonged QTc interval and high B-type natriuretic peptide levels together predict mortality in patients with advanced heart failure

BACKGROUND

The role of QTc interval prolongation in heart failure remains poorly defined. To better understand it, we analyzed the QTc interval duration in patients with heart failure with high B-type natriuretic peptide (BNP) levels and analyzed the combined prognostic impact of prolonged QTc and elevated BNP.

METHODS AND RESULTS

QTc intervals were measured in 241 patients with heart failure who had BNP levels >400 pg/mL. QT interval duration was determined by averaging 3 consecutive beats through leads II and V4 on a standard 12-lead ECG and corrected by using the Bazett formula. QTc intervals were prolonged (>440 ms) in 122 (51%) patients and normal in 119 (49%). The BNP levels in these 2 groups were not significantly different (786+/-321 pg/mL in the prolonged QTc group versus 733+/-274 pg/mL in the normal QTc group, P=0.13). During 6 months of follow-up, 46 patients died, 9 underwent transplantation, and 17 underwent left ventricular assist device implantation. The deaths were attributed to pump failure (n=24, 52%), sudden cardiac death (n=18, 39%), or noncardiac causes (n=4, 9%). Kaplan-Meier survival rates were 3 times higher in the normal QTc group than in the prolonged QTc group (P<0.0001). On multivariate analysis, prolonged QTc interval was an independent predictor of all-cause death (P=0.0001), cardiac death (P=0.0001), sudden cardiac death (P=0.004), and pump failure death (P=0.0006).

CONCLUSIONS

Prolonged QTc interval is a strong, independent predictor of adverse outcome in patients with heart failure with BNP levels >400 pg/mL.

Overview on coenzyme Q10 as adjunctive therapy in chronic heart failure. Rationale, design and end-points of "Q-symbio"--a multinational trial

Energy starvation of the myocardium is probably a dominant feature of heart failure and attention has been directed towards agents which may stabilize myocardial metabolism and maintain adequate energy stores. A reduced myocardial tissue content of the essential redox-component and natural antioxidant Coenzyme Q10 (CoQ10) has been detected in patients with heart failure and the observed level of CoQ10 deficiency was correlated to the severity of heart failure. CoQ10 fulfills various criteria of an obvious adjunct in patients with symptomatic heart failure: it is devoid of significant side effects and it improves symptoms and quality of life. Till this date, several double-blind placebo-controlled trials with CoQ10 supplementation in more than 1000 patients have been positive and statistically significant with respect to various clinical parameters, e.g. improvement in NYHA Class, exercise capacity and reduced hospitalisation frequency. Also treatment with CoQ10 led to a significant improvement of relevant hemodynamic parameters. In only 3 out of 13 double-blind studies comprising 10% of the total number of patients treated the results were neutral. Thus, based on the available controlled data CoQ10 is a promising, effective and safe approach in chronic heart failure. This is why a double-blind multicenter trial with focus on morbidity and mortality has been planned to start in 2003: Q-SYMBIO. Patients in NYHA classes III to IV (N=550) receiving standard therapy are being randomized to treatment with CoQ10 100 mg t.i.d. or placebo in parallel groups. End-points in a short-term evaluation phase of 3 months include symptoms, functional capacity and biomarker status (BNP). The aim of a subsequent 2-year follow-up study is to test the hypothesis that CoQ10 may reduce cardiovascular morbidity (unplanned cardiovascular hospitalisation due to worsening heart failure) and mortality as a composite endpoint. This trial should help to establish the future role of CoQ10 as part of a maintenance therapy in patients with chronic heart failure.