Prognostic information provided by serial measurements of brain natriuretic peptide in heart failure

Ventricular endocrine and mechanical function following thrombolysis for acute myocardial infarction

OBJECTIVE

The objective of this study was to assess natriuretic peptide release following acute myocardial infarction, and its relationship with ventricular function.

METHODS

A total of 44 patients with acute myocardial infarction were studied; 13 anterior, age (57+/-12 years) and 31 inferior, age (58+/-12 years). Peptide levels and left ventricular function by echocardiography were assessed at admission and on days 7 and 30 after thrombolysis. Healthy volunteers (n=21) served as controls.

RESULTS

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) levels rose from admission to day 7 (p=0.002). While ANP remained elevated at day 30 in both groups, BNP levels fell in patients with anterior myocardial infarction (p=0.03). Left ventricular fractional shortening was reduced at admission in the two groups (p=0.01) but returned towards normal in 7 days (p=0.001) in inferior myocardial infarction and in 30 days in anterior myocardial infarction (p=0.02). Left ventricular long axis amplitude was universally reduced at admission (p=0.01) and remained abnormal at day 30 (p=0.01) in both groups. At day 7, BNP and ANP levels inversely correlated with long axis amplitude of lateral wall in anterior myocardial infarction; (r=-0.7, p=0.01). BNP correlated inversely with fractional shortening in anterior myocardial infarction (r=-0.7, p=0.01) at day 30.

CONCLUSION

The elevated peptide levels at 7 days post-myocardial infarction correlate with reduced mechanical activity of the adjacent noninfarcted segment. Natriuretic peptides release seem to be related to failure of compensatory hyperdynamic activity of the noninfarcted area rather than directly from the injured myocardial segments.

Prognosis of decompensated heart failure patients with preserved systolic function is predicted by NT-proBNP variations during hospitalization

BACKGROUND

Almost half of heart failure (HF) patients have preserved left ventricular systolic function (LVSF). Although morbidity is similar in patients with preserved and depressed LVSF, clinicians have limited information on prognostic factors of patients with preserved LVSF. We aimed to evaluate the prognostic value of NT-proBNP in patients with decompensated HF regardless of LVSF.

METHODS

Patients hospitalised due to decompensated HF were followed for 6 months. The primary endpoint was death or hospital readmission. We evaluated 224 patients with NT-proBNP measured at admission and discharge and an echocardiogram performed. NT-proBNP decreased on average during hospitalization in patients with preserved LVSF (n=63) and in patients with depressed LVSF (n=161). The morbidity was not different between patients with preserved and depressed LVSF. Among patients with preserved LVSF, predictors of adverse events were serum creatinine, haemoglobin, NT-proBNP levels at discharge and the variation in NT-proBNP during hospitalisation. Among patients with depressed LVSF, predictors of adverse events were female gender, atrial fibrillation, non-prescription of ACE-inhibitor at discharge, NT-proBNP levels at discharge and the variation in NT-proBNP during hospitalisation.

CONCLUSIONS

These results suggest that, in HF patients with preserved LVSF as in patients with depressed LVSF, NT-proBNP can play a role as a tool to identify patients at risk of an adverse outcome.

Decrease in plasma B-type natriuretic peptide early after initiation of cardiac resynchronization therapy predicts clinical improvement at 12 months

BACKGROUND

Decrease in neurohormonal activation during pharmacotherapy for chronic heart failure (CHF) is associated with haemodynamic and clinical improvement. We tested the hypothesis that changes in neurohormonal activation after initiation of cardiac resynchronization therapy (CRT) predict its long-term clinical effect.

METHODS

The study group included 43 patients with CHF (37 males, mean age 62+/-9 years, NYHA class 3.2+/-0.4, QRS duration 195+/-24 ms) who underwent successful implantation of a CRT system. Pharmacotherapy remained stable during the first 3 months of follow-up. Plasma levels of B-type natriuretic peptide (BNP) and big endothelin-1 (big ET-1) were evaluated before and 3 months after implantation. Clinical, echocardiographic and exercise parameters were monitored for a mean period of 25.8+/-6.7 months.

RESULTS

At 12 months of follow-up 13 non-responders were identified (no improvement in NYHA class (n=10), urgent heart transplantation (n=2) and death due to progressive heart failure (n=1)). CRT resulted in a significant reduction in neurohormone levels (BNP 345.4+/-346 vs. 267.7+/-320.8 pg/ml, p<0.01, big ET-1 3.11+/-1.50 vs. 2.50+/-1.56 fmol/ml p<0.05), especially in responders. Percentage change in BNP level was a stronger predictor of long-term clinical improvement than clinical, echocardiographic and exercise parameters at 3 months of follow-up.

CONCLUSIONS

Percentage change in plasma BNP levels from baseline to 3 months was the strongest predictor of long-term response to CRT and may have potential to predict outcome.

Intraindividual variation of amino-terminal pro-B-type natriuretic peptide levels in patients with stable heart failure

This study aimed to evaluate how large the variation between measurements of N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) can be in patients with clinically stable heart failure (HF). The fluctuation of NT-pro-BNP in patients with HF has not been previously evaluated. Patients with chronic, stable HF were evaluated at 3-week intervals. The relative (percentage of baseline) difference between the 2 NT-pro-BNP measurements and their mean were calculated. In total, 118 double measurements of NT-pro-BNP were obtained. Changes in NT-pro-BNP measurements were determined according to quartiles of mean NT-pro-BNP. The median baseline NT-pro-BNP level was 1,323 pg/ml (25th and 75th percentiles 433 and 2,258), and the median second NT-pro-BNP level was 1,394 pg/ml (25th and 75th percentiles 475 and 2,353) (p = 0.34). Among pairs of measurements in the first quartile (NT-pro-BNP <450 pg/ml), the 5th and 95th percentiles of the distribution of relative differences were -86% and +197%. In the second (450 to 1,300 pg/ml), third (1,300 to 2,300 pg/ml), and fourth (>2,300 pg/ml) quartiles, the 5th and 95th percentiles of relative differences were -42% and +78%, -29% and +38%, and -30% and +37%, respectively, of the baseline values. In conclusion, the results support the clinical use of NT-pro-BNP in the monitoring of patients with HF with NT-pro-BNP levels >1,300 pg/ml. In these patients, variations between 1/3 less and about 40% more can be expected without clinical improvement or deterioration.

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.

Neonate with vein of Galen malformation and heart failure: serial changes in plasma B-type natriuretic peptide following endovascular embolization

We report a neonate with vein of Galen malformation (VGM) who developed congestive heart failure (CHF) early after birth. Serial changes in plasma B-type natriuretic peptide (BNP) following an endovascular embolization procedure for VGM were mirrored in his clinical CHF status. The plasma BNP level markedly increased to 1800 pg/ml (normal, <100 pg/ml) in accordance with the severity of CHF. It rapidly decreased to 356 pg/ml during the first week after endovascular embolization for VGM. In the following 3 weeks there was an unexpected upward trend in plasma BNP despite echocardiography revealing normal biventricular function. After additional evaluation and treatment for CHF, BNP decreased again and the patient's clinical status concurrently improved. The patient was discharged with a normal BNP level. Monitoring serial plasma BNP provides valuable information regarding the need for additional evaluation or treatment of newborns with CHF and may be used to document improvement.

Top of the charts: download versus citations in the International Journal of Cardiology

The medical literature is growing at an alarming rate. Research assessment exercises, research quality frameworks, league tables and the like have attempted to quantify the volume, quality and impact of research. Yet the established measures (such as citation rates) are being challenged by the sheer number of journals, variability in the "gold standard" of peer-review and the emergence of open-source or web-based journals. In the last few years, we have seen a growth in downloads to individual journal articles that now easily exceeds formal journal subscriptions. We have recorded the 10 top cited articles over a 12-month period and compared them to the 10 most popular articles being downloaded over the same time period. The citation-based listing included basic and applied, observational and interventional original research reports. For downloaded articles, which have shown a dramatic increase for the International Journal of Cardiology from 48,000 in 2002 to 120,000 in 2003 to 200,000 in 2004, the most popular articles over the same period are very different and are dominated by up-to-date reviews of either cutting-edge topics (such as the potential of stem cells) or of the management of rare or unusual conditions. There is no overlap between the two lists despite covering exactly the same 12-month period and using measures of peer esteem. Perhaps the time has come to look at the usage of articles rather than, or in addition to, their referencing.

Advances in the non-drug, non-surgical, non-device management of chronic heart failure

There have been many articles, reviews and editorials about the recent advances in pharmaceutical and device management of chronic heart failure in this and other journals over the last few years. What has been less praised are the significant advances we have made in understanding the best management of heart failure using other non-drug, non-surgical, non-device approaches. Approaches as diverse as nutrition, education, exercise, physiotherapy, psychotherapy and therapies for sleep-disordered breathing have shown considerable promise in improving the lot of our chronic heart failure (CHF) patients. Chronic heart failure is a common condition with a poor prognosis. It generates many debilitating symptoms for the sufferer. Non-pharmacologic treatment modalities play an important role alongside effective modern pharmaceutical, surgical and device therapies in relieving symptoms and improving prognosis. These treatments include those lifestyle measures that reduce the risk of underlying diseases such as coronary artery disease, diabetes, and hypertension lifestyle interventions of benefit in established CHF. Recent advances are reviewed including specialist nursing care, multi-disciplinary heart failure clinics, exercise rehabilitation, the treatment of sleep-disordered breathing, depression, obesity and cachexia. The day of the multi-disciplinary patient-centred CHF clinic has arrived and all sufferers deserve experienced management using all these approaches.

Evaluation and management of the acutely dyspneic patient: the role of biomarkers

The etiology of dyspnea can often be difficult to rapidly and accurately determine and can delay timely and appropriate therapies. The current literature reveals important diagnostic, prognostic, and therapeutic implications of several currently used biomarkers: sensitive d -dimer, myoglobin, creatine kinase-MB, cardiac troponins, and b-type natriuretic peptide. These biomarkers were found to have a high sensitivity and negative predictive value for rapidly ruling out potential serious etiologies of dyspnea, namely, pulmonary embolism (PE), acute myocardial infarction (AMI), and congestive heart failure (CHF). In the setting of a low to moderate pretest probability of PE, a negative sensitive d -dimer can rule out a PE with 97% accuracy. After 10 hours from the onset of symptoms, normal levels of myoglobin, creatine kinase-MB, and cardiac troponin I can rule out an AMI with greater than 96% accuracy. A b-type natriuretic peptide level less than 80 pg/mL can confidently rule out decompensated CHF with greater than 99% accuracy. However, no literature was found analyzing the use of these biomarkers in combination. A dyspnea biomarker panel could rapidly and accurately assist a clinician to rule out PE, AMI, and CHF. If a PE, AMI, or CHF is determined to be the cause of dyspnea, a biomarker panel could help risk stratify and help determine initial therapies. Subsequent clinical research is needed to corroborate this postulation.

N-Terminal–Pro-Brain Natriuretic Peptide Predicts Outcome After Hospital Discharge in Heart Failure Patients

Background— Heart failure (HF) is responsible for a huge burden in hospital care. Our goal was to evaluate the value of N-terminal–pro-brain natriuretic peptide (NT-proBNP) in predicting death or hospital readmission after discharge of HF patients.

Methods and Results— We included 182 patients consecutively admitted to hospital because of decompensated HF. Patients were followed up for 6 months. The primary end point was death or readmission. Twenty-six patients died in hospital. The median admission NT-proBNP level was 6778.5 pg/mL, and the median level at discharge was 4137.0 pg/mL ( P <0.001). Patients were classified into 3 groups: (1) decreasing NT-proBNP levels by at least 30% (n=82), (2) no significant modifications on NT-proBNP levels (n=49), and (3) increasing NT-proBNP levels by at least 30% (n=25). The primary end point was observed in 42.9% patients. Variables associated with an increased hazard of death and/or hospital readmission in univariate analysis were length of hospitalization, heart rate, signs of volume overload, no use of ACE inhibitors, higher NYHA class at discharge, admission and discharge NT-proBNP, and the change in NT-proBNP levels. The variation in NT-proBNP was the strongest predictor of an adverse outcome. Independent variables associated with an increased risk of readmission or death were signs of volume overload and the change in NT-proBNP levels.

Conclusions— Variations in NT-proBNP levels are related to hospital readmission and death within 6 months. NT-proBNP levels are potentially useful in the evaluation of treatment efficacy and might help clinicians in planning discharge of HF patients. Whether therapeutic strategies aimed to lower NT-proBNP levels modify prognosis warrants future investigation.

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.

NT-proBNP and BNP: biomarkers for heart failure management

Guidelines for the pharmacological treatment of heart failure (HF) are based on results from large clinical trials demonstrating benefit. State of the art pharmacological management of HF assumes that target doses should be the same as those used in trials. Thus equal doses are recommended for all in practical guidelines, but this strategy might not fit individual needs. NT-proBNP and BNP emerged as potential biomarkers of clinical interest in HF management. NT-proBNP and BNP are related to HF severity and to clinical status. NT-proBNP and BNP are strongly associated with prognosis across the whole spectrum of HF patients. A pilot study has shown that NT-proBNP-guided therapy is associated with improved outcome in HF. Although at present there are still few data to make firm recommendations on the use of NT-proBNP or BNP levels as biomarkers for HF management, future studies will provide further insight on this issue.