Role of brain natriuretic peptide in risk stratification of patients with congestive heart failure

[Brain natriuretic peptide as a predictor of heart failure in patients with permanent pacemaker]

INTRODUCTION

Brain natriuretic peptide (BNP) has a role in control of cardiovascular and renal functions.

OBJECTIVE

The objective was to assess the predictive value of BNP levels for development of heart failure in patients with permanent pacemakers.

METHOD

In patients with implanted DDD pacemakers, BNP levels were measured at rest and after exercise testing, on DDD and VVI modes. There were 42 patients (25 males; 59.5%), without symptoms or signs of coronary disease or heart failure, and with normal echocardiograms. According to BNP levels, the patients were divided into three groups: with BNP levels lower than 80 pg/ml, BNP ranging from 81-150 pg/ml, and BNP levels over 151 pg/ml.

RESULTS

In the first group (27 patients), BNP levels were significantly higher on VVI compared to DDD mode, both at rest and after exercise (p < 0.01), with all BNP levels within normal range. In the second group (5 pts), BNP levels at rest were also significantly higher on VVI than on DDD mode, p < 0.05. After exercise, these values were also higher on VVI compared to DDD mode, but without statistical significance. The third group (10 pts) as a whole had higher BNP values on VVI compared to DDD mode, with no statistical significance. In patients from this group who later developed heart failure, BNP levels were found to be significantly lower on DDD as opposed to VVI mode at rest, p < 0.05, and even higher significance was found after exercise, p < 0.01. After 6-year follow-up, 2 out of 5 patients from the second group developed dilated cardiomyopathy, and 8/10 patients in the third group experienced heart failure with LV EF 34.1 +/- 10%, LV EDD 6.1 +/- 0.42 cm, LV ESD 4.8 +/- 0.45 cm. Five of these patients died within the follow-up period.

CONCLUSION

The increased BNP levels can be valuable for early screening of patients with higher risk of heart failure. In patients with increased BNP at the time of pacemaker implantation, DDD pacing is a modality of choice.

Comparison of brain natriuretic peptide (BNP) and amino-terminal ProBNP for early diagnosis of heart failure

BACKGROUND

We compared the diagnostic accuracy of brain natriuretic peptide (BNP) and amino-terminal proBNP (NT-proBNP) for diagnosis of preclinical and mild heart failure (HF).

METHODS

We assayed plasma NT-proBNP and BNP in 182 healthy controls and in a prospective cohort of 820 HF patients divided according to the American Heart Association/American College of Cardiology classification. These included 86 patients in stage A [mean (SE) ejection fraction 61% (1%); mean (SE) age 47 (2) years], 255 in stage B [65% (2%); 62 (1) years], 420 patients in stage C [35% (1%); 68 (1) years] and 59 in stage D [25% (1%); 74 (1) years]. Diagnostic accuracies of BNP and NT-proBNP were evaluated by ROC analysis, and a multivariate linear regression model was applied to predict HF staging.

RESULTS

Median BNP and NT-proBNP concentrations increased from stage A to D 57-fold and 107-fold, respectively. Both assays were accurate (P <0.001) in separating stage B from controls or stage A, and stage C from controls or stage A or B. NT-proBNP was more accurate (P <0.001) than BNP in differentiating stage C from stages A and B patients and controls and was a better predictor of HF classification in a model including age, sex, and renal function (P <0.001).

CONCLUSIONS

Monitoring BNP or NT-proBNP enabled identification of asymptomatic patients at risk for the development of HF. NT-proBNP showed better accuracy than BNP for identifying mild HF.

Variability of NT-proBNP plasma and urine levels in patients with stable heart failure: a 2-year follow-up study

OBJECTIVES

To examine N-terminal pro-brain natriuretic peptide (NT-proBNP) variability in plasma and urine samples of patients with stable heart failure (HF) during a 24-month follow-up.

DESIGN

Prospective study.

SETTING

Teaching hospital based study.

PATIENTS

74 clinically and functionally stable patients (NYHA class 2+/-0.5) out of 114 patients diagnosed with HF were followed up, and NT-proBNP plasma and urine levels were measured at baseline, 12 and 24 months.

RESULTS

Significant differences in mean urinary levels (p<0.01) were found during follow-up, but no changes were found in plasma. Bland-Altman plots showed few variations in plasma percentages in the three intervals (stage I-basal; stage II-stage I; stage II-basal) with a coefficient of reproducibility (CR) of 22%, 21% and 25%, respectively. Changes in NT-proBNP urinary levels had a CR of 7.1%, 6.8% and 9.4% at the three intervals, respectively. A good correlation was found between plasma and urinary levels of NT-proBNP (p<0.001) and between the different NT-proBNP plasma (p<0.001) and urine measurements (p<0.001).

CONCLUSIONS

NT-proBNP plasma and urine levels show good stability in a 24-month follow-up of patients with stable heart failure. Thus, assessment of urinary and plasma NT-proBNP concentrations may be a useful tool for monitoring patients with HF during follow-up. The results suggest that variations in peptide concentrations exceeding 22% in plasma and 7% in urine in a 12-month follow-up and 25% and 9% in a 24-month follow-up may indicate pathophysiological changes.

Lack of association between worsening renal function and mortality in heart failure patients treated with nesiritide

BACKGROUND

Nesiritide is approved for the treatment of decompensated heart failure. Because nesiritide may exacerbate renal dysfunction, it has been claimed that there may be a link between worsening renal function caused by nesiritide and increased mortality.

AIMS

We analyzed our inpatient experience with nesiritide to determine if changes in renal function were associated with worsened mortality.

METHODS AND RESULTS

A retrospective study of 167 patients [65% male, median age 70 years, left ventricular ejection fraction (LVEF) 30%, glomerular filtration rate (GFR) 36 mL/min/1.73 m(2), serum creatinine (sCr)1.8 mg/dL] treated with standard dose nesiritide was undertaken for the period September 2001-March 2005. Mortality was 12.5% at 1 month and 51% at 24 months (median follow-up was 5.4 months [interquartile ranges (IQR) 1.3, 18.6]. Higher mortality was associated with lower pre-infusion GFR (hazard ratio for a 10 mL/min/1.72 m(2) decrease=1.22, p=0.004). Pre-to-post nesiritide changes in GFR (median 0.0, IQR-5.8, 8.4; p=0.51) and creatinine (median 0.0, IQR -0.3, 0.3; p=0.91), however, were not significant and not detected to be associated with worsened mortality by Cox proportional hazards (p=0.46 and p=0.40, respectively).

CONCLUSIONS

While we found that nesiritide infusion in decompensated heart failure patients worsened renal function (decrease in GFR) in 29% of patients, changes in renal function could not be related to an incremental worsening of mortality. Our findings do not support an association of worsening renal function and worsening mortality after nesiritide.

N-Terminal Prohormone Brain Natriuretic Peptide as a Marker for Detecting Low Functional Class Patients and Candidates for Cardiac Transplantation: Linear Correlation With Exercise Tolerance

BACKGROUND

N-terminal prohormone brain natriuretic peptide (NT Pro BNP) plasma levels have been associated with indices of left ventricular (LV) function and aerobic capacity in heart failure. The aim of our study was to use NT Pro BNP for the prediction of low functional class patients and also to detect candidates for cardiac transplantation.

METHODS

We studied 100 patients with impaired left ventricular (LV) function. Mean LV ejection fraction (LVEF) was 35% +/- 9%. Blood samples for NT Pro BNP assessment were taken at baseline during treadmill exercise testing. LV cavity diameters, left atrial size, and LVEF were measured by echocardiography.

RESULTS

Plasma levels of NT Pro BNP correlated significantly with peak oxygen consumption (VO(2)) values (r = -0.77, p < 0.001). LVEF correlated well with NT Pro BNP (r = -0.67, p < 0.001). NT Pro BNP plasma levels correlated strongly with New York Heart Association functional class (r = 0.70, p < 0.001). NT Pro BNP values exceeding 335 pg/ml showed 83% sensitivity and 76% specificity for detecting VO(2) values below 20 ml/kg/min (area under the curve [AUC] = 86%, p < 0.001). NT Pro BNP plasma levels exceeding 1,190 pg/ml showed 83% sensitivity and 86% specificity for detecting VO(2) of less than 14 ml/kg/min (AUC = 90%, p < 0.001). NT Pro BNP plasma levels exceeding 1,610 pg/ml showed 87% sensitivity and specificity 82% for detecting VO(2) of less than 10 ml/kg/min (AUC = 90%, p < 0.001). NT Pro BNP plasma levels exceeding 680 pg/ml showed 91% sensitivity and 73% specificity for detecting LVEF of less than 28% (AUC = 86%, p < 0.001).

CONCLUSIONS

NT Pro BNP plasma levels correlate both with LVEF and aerobic capacity, can predict low functional cardiopulmonary exercise capacity in patients with impaired left ventricular function, and are useful for detecting candidates for cardiac transplantation.

Relation of B-type natriuretic peptide levels before and after exercise and functional capacity in patients with idiopathic dilated cardiomyopathy

Although much is known about the value of B-type natriuretic peptide (BNP) at rest, the significance of the responsiveness of BNP during exercise in patients with chronic heart failure (HF) without coronary artery disease remains to be established. A role of BNP release during exercise in the functional disability of patients with chronic HF and idiopathic dilated cardiomyopathy (IDC) was hypothesized. One hundred five consecutive patients with an established diagnosis of HF and IDC who underwent symptom-limited cardiopulmonary exercise testing were studied. BNP was measured immediately before exercise and within 1 minute of the end of exercise. BNP at rest increased significantly at peak exercise (median from 66.5 (first, third quartiles 18, 168) to 72.0 pg/ml (26, 208), p <0.001), but BNP response was not uniform. BNP response increased in 63% of patients, did not change in 22%, and decreased in 15%. BNP at rest and BNP response showed an inverse correlation (p <0.001, r = -0.523). Aging and low left ventricular ejection fraction were independent predictors of higher BNP levels at rest, but lower BNP response. Beta-blocker therapy did not influence BNP response. BNP at rest correlated negatively with functional capacity (p <0.001, r = -0.516), whereas BNP response correlated positively (p = 0.002, r = 0.326). Patients with BNP release (vs patients without) had higher maximum oxygen consumption (19.2 +/- 5.1 vs 15.9 +/- 3.6, p <0.001), better functional capacity (59 +/- 13% vs 50 +/- 15%, p = 0.002), and lower minute ventilation/carbon dioxide production slope (33.6 +/- 4.8 vs 36.5 +/- 7.7, p = 0.026) independent of other clinical parameters. In conclusion, BNP release during exercise could be a determinant of functional capacity in patients with chronic HF and IDC.

Plasma brain natriuretic peptide-guided therapy to improve outcome in heart failure: the STARS-BNP Multicenter Study

OBJECTIVES

The aim of this multicenter study was to evaluate the prognostic impact of a therapeutic strategy using plasma brain natriuretic peptide (BNP) levels.

BACKGROUND

The prognosis of chronic heart failure (CHF) remains poor, even among patients treated in specialized departments.

METHODS

A total of 220 New York Heart Association functional class II to III patients considered optimally treated with angiotensin-converting enzyme inhibitors (ACEIs), beta-blockers, and diuretics by CHF specialists were randomized to medical treatment according to either current guidelines (clinical group) or a goal of decreasing BNP plasma levels <100 pg/ml (BNP group). Outpatient visits were scheduled every month for 3 months, then every 3 months. The primary combined end point was CHF-related death or hospital stay for CHF.

RESULTS

Both groups were similar for baseline clinical and biological characteristics. Left ventricular ejection fraction was slightly lower in the BNP group than in the clinical group (29.9 +/- 7.7% vs. 31.8 +/- 8.4%, p = 0.05). At the end of the first 3 months, all types of drugs were changed more frequently in the BNP group. Mean dosages of ACEIs and beta-blockers were significantly higher in the BNP group (p < 0.05), whereas the mean increase in furosemide dosage was similar in both groups. During follow-up (median 15 months), significantly fewer patients reached the combined end point in the BNP group (24% vs. 52%, p < 0.001).

CONCLUSIONS

In optimally treated CHF patients, a BNP-guided strategy reduced the risk of CHF-related death or hospital stay for CHF. The result was mainly obtained through an increase in ACEI and beta-blocker dosages.

B-type natriuretic peptide release in the coronary effluent after acute transient ischaemia in humans

BACKGROUND

The association between B-type natriuretic peptide (BNP) and coronary artery disease is not fully understood.

OBJECTIVE

To assess whether ischaemia per se is a stimulus for BNP secretion.

SETTING

University tertiary hospital, Spain (Virgen de la Arrixaca).

DESIGN

Prospective interventional study.

PATIENTS

11 patients (55 (9) years, left ventricular ejection fraction (LVEF) 45% (7%) with a non-complicated anterior myocardial infarction (MI) and isolated stenosis of the left anterior descending (LAD) coronary artery, successfully treated by primary angioplasty.

INTERVENTIONS

11.0 (0.9) days after MI, the LAD was occluded (20 min) for intracoronary infusion of progenitor cells. Blood samples were obtained from the femoral artery (peripheral circulation (PC)) and the coronary sinus (coronary circulation (CC)) immediately before and after coronary occlusion.

MAIN OUTCOME MEASURES

BNP (pg/ml) was measured and ischaemia biomarkers were monitored.

RESULTS

During coronary occlusion, all patients experienced transitory chest pain and ST-segment dynamic changes. After coronary occlusion, lactic acid levels rose in CC (1.42 (0.63) -1.78 (0.68) ng/ml, p = 0.003). Myoglobin and cardiac troponin T did not differ in CC or PC at 24 h. No differences were found in LVEF (+0.18% (2.4)%, p = 0.86) and motion score index (-0.02 (0.06), p = 0.37). Before occlusion, BNP levels did not differ significantly in CC versus PC (253 (56) vs 179 (34), p = 0.093). After occlusion, BNP showed a significant increase in CC (vs 332 (61), p = 0.004), but no change occurred in PC (vs 177 (23), p = 0.93), and circulating BNP levels were higher in CC versus PC (p = 0.008).

CONCLUSIONS

In response to acute ischaemia, BNP levels immediately increase in coronary sinus but not at the peripheral level. BNP release in the coronary effluent may exert local beneficial effects.

Interpretation of B-type natriuretic peptide in cardiac disease and other comorbid conditions

B-Type natriuretic peptide (BNP) is elevated in states of increased ventricular wall stress. BNP is most commonly used to rule out congestive heart failure (CHF) in dyspneic patients. BNP levels are influenced by age, gender and, to a surprisingly large extent, by body mass index (BMI). In addition, it can be elevated in a wide variety of clinical settings with or without CHF. BNP is elevated in other cardiac disease states such as the acute coronary syndromes, diastolic dysfunction, atrial fibrillation (AF), amyloidosis, restrictive cardiomyopathy (RCM), and valvular heart disease. BNP is elevated in non-cardiac diseases such as pulmonary hypertension, chronic obstructive pulmonary disease, pulmonary embolism, and renal failure. BNP is also elevated in the setting of critical illness such as in acute decompensated CHF (ADHF) and sepsis. This variation across clinical settings has significant implications given the increasing frequency with which BNP testing is being performed. It is important for clinicians to understand how to appropriately interpret BNP in light of the comorbidities of individual patients to maximize its clinical utility. We will review the molecular biology and physiology of natriuretic peptides as well as the relevant literature on the utilization of BNP in CHF as well as in other important clinical situations, conditions that are commonly associated with CHF and or dyspnea.

Canadian Cardiovascular Society Consensus Conference recommendations on heart failure update 2007: Prevention, management during intercurrent illness or acute decompensation, and use of biomarkers

Heart failure is common, yet it is difficult to treat. It presents in many different guises and circumstances in which therapy needs to be individualized. The Canadian Cardiovascular Society published a comprehensive set of recommendations in January 2006 on the diagnosis and management of heart failure, and the present update builds on those core recommendations. Based on feedback obtained through a national program of heart failure workshops during 2006, several topics were identified as priorities because of the challenges they pose to health care professionals. New evidence-based recommendations were developed using the structured approach for the review and assessment of evidence adopted and previously described by the Society. Specific recommendations and practical tips were written for the prevention of heart failure, the management of heart failure during intercurrent illness, the treatment of acute heart failure, and the current and future roles of biomarkers in heart failure care. Specific clinical questions that are addressed include: which patients should be identified as being at high risk of developing heart failure and which interventions should be used? What complications can occur in heart failure patients during an intercurrent illness, how should these patients be monitored and which medications may require a dose adjustment or discontinuation? What are the best therapeutic, both drug and nondrug, strategies for patients with acute heart failure? How can new biomarkers help in the treatment of heart failure, and when and how should BNP be measured in heart failure patients? The goals of the present update are to translate best evidence into practice, to apply clinical wisdom where evidence for specific strategies is weaker, and to aid physicians and other health care providers to optimally treat heart failure patients to result in a measurable impact on patient health and clinical outcomes in Canada.

Indications for Heart Transplantation in Pediatric Heart Disease

Background— Since the initial utilization of heart transplantation as therapy for end-stage pediatric heart disease, improvements have occurred in outcomes with heart transplantation and surgical therapies for congenital heart disease along with the application of medical therapies to pediatric heart failure that have improved outcomes in adults. These events justify a reevaluation of the indications for heart transplantation in congenital heart disease and other causes of pediatric heart failure.

Methods and Results— A working group was commissioned to review accumulated experience with pediatric heart transplantation and its use in patients with unrepaired and/or previously repaired or palliated congenital heart disease (children and adults), in patients with pediatric cardiomyopathies, and in pediatric patients with prior heart transplantation. Evidence-based guidelines for the indications for heart transplantation or retransplantation for these conditions were developed.

Conclusions— This evaluation has led to the development and refinement of indications for heart transplantation for patients with congenital heart disease and pediatric cardiomyopathies in addition to indications for pediatric heart retransplantation.

Nocturnal oxygen therapy prevents progress of congestive heart failure with central sleep apnea

BACKGROUND

Sleep disordered breathing has been reported to be associated with congestive heart failure (CHF). Nocturnal oxygen has been shown to abolish apnea. The aim of this study is to examine whether nocturnal oxygen reduces sympathetic nerve activity, and prevents progress of CHF.

METHODS

93 patients with left ventricular ejection fractions < 60%, were examined with overnight saturation monitoring for an oxygen desaturation index. Subjects with oxygen desaturation of 4% > or = 4/h were examined with polysomnography. Apnea-hypopnea index (AHI) was calculated as the total number of episodes of apnea and hypopnea per hour of sleep. We started nocturnal oxygen for the patients with AHI > or = 20. Urinary and plasma catecholamines concentrations, serum brain natriuretic peptide, human atrial natriuretic peptide, and endothelial nitric oxide synthase levels were measured before and after starting oxygen.

RESULTS

Compared among the three groups, CHF with central sleep apnea (CHF-CSA) group had significantly higher 24-h urinary adrenaline (CHF-CSA: 4.411+/-2.940 micromol/day, CHF with obstructive sleep apnea (CHF-OSA): 2.686+/-1.084 micromol/day, CHF without apnea (CHF-N): 3.178+/-1.778 micromol/day, P<0.05). Oxygen therapy significantly decreased AHI and 4 serum BNP levels (from 91.75+/-80.35 pg/ml to 52.75+/-45.70 pg/ml, mean change=33.85 pg/ml, P=0.0208). Serum eNOS levels were lower in CHF-CSA group and CHF-OSA group than in CHF-N group (CHF-CSA: 15.89+/-10.75 pg/ml, CHF-OSA: 7.46+/-3.91 pg/ml, CHF-N: 27.33+/-14.83 pg/ml, P<0.05).

CONCLUSIONS

Nocturnal oxygen may prevent progress of CHF with central sleep apnea.

Prognostic role of B-type natriuretic peptide in patients with diabetes and acute decompensated heart failure

BACKGROUND

Several studies have reported the prognostic value of natriuretic peptides, but their predictive value in patients with diabetes mellitus is unknown. The aim of the study was to test the hypothesis that measurement of brain natriuretic peptide (BNP) levels in ambulatory patients with congestive heart failure (CHF) and diabetes can predict the occurrence of cardiovascular events at 6-month follow-up.

METHODS

We enrolled 145 consecutive patient with diabetes [age 72 +/- 9 years, hypertension (21%), ischaemic heart disease (52%), atrial fibrillation (22%), preserved left ventricular function (29%)] seen in the outpatient heart failure clinic after an acute episode of cardiac failure.

RESULTS

The median (25th/75th interquartile range) BNP concentrations at discharge were 186 (75-348) pg/ml. At 6-month clinical follow-up 10/145 (7%) subjects had died and 31/145 (21%) had been readmitted because of cardiac decompensation. BNP values of 200 and 500 pg/ml were found to have the best compromise between sensitivity (88 and 46%, respectively) and specificity (71 and 89%, respectively) for predicting events at 6 months. Multivariate Cox regression analysis identified only two parameters as predictors of events: serum creatinine [hazard ratio (HR) = 3.3; P = 0.02], and BNP plasma level BNP cut-off values (HR = 3.8; P = 0.03 for 201-499 pg/ml and HR = 7.7; P = 0.001 for > or = 500 pg/ml).

CONCLUSION

These results suggest that BNP and serum creatinine are strong predictors of clinical events in patients with diabetes and CHF. In these patients, clinical outcome might be stratified by plasma BNP levels.

The Biologic Variability of B-Type Natriuretic Peptide and N-Terminal Pro-B-Type Natriuretic Peptide in Stable Heart Failure Patients

BACKGROUND

There are conflicting data on the usefulness of B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) in the optimization of therapy for heart failure (HF). Discordant results may be explained by the intra-individual variability of these peptides. This study evaluates the intraindividual variability of BNP and NT-proBNP and the impact of the covariates of age, sex, and renal function.

METHODS AND RESULTS

Stable HF patients attending our unit were included. Blood samples were drawn 1 hour apart on 2 occasions 1 week apart. Forty-five patients were enrolled (69.6 +/- 12.1 years, 64% male, 84% systolic HF). Within-hour and within-week intraindividual variability were: 6.9% and 21.1% for NT-proBNP; 14.6% and 28.4% for BNP (P < .01 for within-hour comparison of BNP and NT-proBNP). Reference change values over 1 week for NT-proBNP and BNP were 49.2% and 66.2%, respectively. There were no significant relationships identified between variability and age, gender, or glomerular filtration rate.

CONCLUSION

There is considerable intraindividual variability in these peptides in stable HF patients. Changes of approximately 50% and 66% for NT-proBNP and BNP from week to week are needed to indicate an altered clinical status and caution should be exercised in interpreting serial changes in these peptide levels when monitoring patient responses to treatment or clinical status.

Brain Natriuretic Peptide Levels and Left Ventricular Functional Recovery in a Chronic Heart Failure Population

Due to the poor correlation between symptoms and left ventricular (LV) ejection fraction in a chronic heart failure (HF) population, the ability to identify patients who demonstrate LV functional recovery poses a dilemma for the clinician. Serial echocardiograms are not practical in a large outpatient HF population. Plasma brain natriuretic peptide (BNP) levels have a high predictive value for excluding patients with ventricular dysfunction and therefore could serve as a marker for identifying patients who demonstrate improved LV function. To evaluate this point, the researchers obtained baseline BNP levels in 380 chronic systolic HF patients seen in an outpatient HF clinic. Each patient already had a baseline echocardiogram performed before or on entry into the clinic. Fifty patients were identified in this group as having normal BNP levels (< or = 100 pg/mL). Echocardiograms were then repeated in this group and compared with initial echocardiographic data obtained from a retrospective chart review. The results showed that the mean LV ejection fraction for the group was increased (p < 0.001), mean LV internal dimension was decreased (p < 0.001), and the number of patients with an ejection fraction > 50% increased from zero to 20 (p < 0.001). Thus, normal BNP levels can correlate with LV recovery and could potentially offer a cost-effective method of assessing changes in LV function in patients with chronic HF.

Homocysteine, brain natriuretic peptide and chronic heart failure: a critical review

Chronic heart failure (CHF) is a major public health problem causing considerable morbidity and mortality. Recently, plasma homocysteine (HCY) has been suggested to be significantly increased in CHF patients. This article reviews the relation between hyperhomocysteinemia (HHCY) and CHF. Clinical data indicate that HHCY is associated with an increased incidence, as well as severity, of CHF. In addition, HCY correlates with brain natriuretic peptide (BNP), a modern biochemical marker of CHF, which is used for diagnosis, treatment guidance and risk assessment. Animal studies showed that experimental HHCY induces systolic and diastolic dysfunction, as well as an increased BNP expression. Moreover, hyperhomocysteinemic animals exhibit an adverse cardiac remodeling characterized by accumulation of interstitial and perivascular collagen. In vitro superfusion experiments with increasing concentrations of HCY in the superfusion medium stimulated myocardial BNP release independent from myocardial wall stress. Thus, clinical and experimental data underline a correlation between HHCY and BNP supporting the role of HHCY as a causal factor for CHF. The mechanisms leading from an elevated HCY level to reduced pump function and adverse cardiac remodeling are a matter of speculation. Existing data indicate that direct effects of HCY on the myocardium, as well as nitric oxide independent vascular effects, are involved. Preliminary data from small intervention trials have initiated the speculation that HCY lowering therapy by micronutrients may improve clinical as well as laboratory markers of CHF.

In conclusion, HHCY might be a potential etiological factor in CHF. Future studies need to explore the pathomechanisms of HHCY in CHF. Moreover, larger intervention trials are needed to clarify whether modification of plasma HCY by B-vitamin supplementation improves the clinical outcome in CHF patients.

Clin Chem Lab Med 2007;45:1633–44.

Usefulness of Inhospital Change in B-Type Natriuretic Peptide Levels in Predicting Long-Term Outcome in Elderly Patients Admitted for Decompensated Heart Failure

The usefulness of repeated measures of B-type natriuretic peptide (BNP) in elderly subjects with decompensated heart failure to improve risk stratification remains poorly known. This prospective cohort study included 61 consecutive patients older than 70 years (mean age, 82.7 years) hospitalized for decompensated heart failure. Clinical, radiologic, biologic, and echographic data were collected at admission and at discharge. The median BNP level at admission was 1136 pg/mL and the mean change during the hospitalization was -32%. Cardiac death or readmission were best predicted by the change in BNP levels, with the poorest prognosis in patients who did not achieve a decrease of at least 40% (hazard ratio, 4.03; 95% confidence interval, 1.50-10.84 in multivariate analysis). Admission of an elderly patient for decompensated heart failure is a daily situation in clinical practice, in which 2 BNP measurements seem to provide reliable information on long-term prognosis.

N-Terminal Pro-Brain Natriuretic Peptide: An Independent Risk Predictor of Cardiovascular Congestion, Mortality, and Adverse Cardiovascular Outcomes in Chronic Peritoneal Dialysis Patients

This study was performed to determine whether the N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is a useful biomarker in predicting cardiovascular congestion, mortality, and cardiovascular death and event in chronic peritoneal dialysis (PD) patients. A prospective cohort study was conducted in 230 chronic PD patients in a dialysis unit of a university teaching hospital. Serum NT-pro-BNP was measured at baseline together with echocardiography and dialysis indices. Each patient was followed for 3 yr from the day of enrollment or until death. Time to develop first episode of cardiovascular congestion and other cardiovascular event and time to mortality and cardiovascular death were studied in relation to NT-pro-BNP. NT-pro-BNP showed the strongest correlation with residual GFR, followed by left ventricular ejection fraction and left ventricular mass index. In the univariate Cox regression model, NT-pro-BNP was a significant predictor of cardiovascular congestion, mortality, and cardiovascular death and event. In the fully adjusted multivariable Cox regression analysis that included residual GFR, left ventricular ejection fraction, and left ventricular mass index, the hazard ratios for cardiovascular congestion, mortality, composite end point of mortality and cardiovascular congestion, and cardiovascular death and event for patients of the fourth quartile were 4.25 (95% confidence interval [CI] 1.56 to 11.62; P = 0.005), 4.97 (95% CI 1.35 to 18.28; P = 0.016), 5.03 (95% CI 2.07 to 12.26; P < 0.001), 7.50 (95% CI 1.36 to 41.39; P = 0.021), and 9.10 (95% CI 2.46 to 33.67; P = 0.001), respectively, compared with the first quartile. These data showed that NT-pro-BNP is an important risk predictor of cardiovascular congestion, mortality, and adverse cardiovascular outcomes in chronic PD patients and adds important prognostic information beyond that contributed by left ventricular hypertrophy, systolic dysfunction, and other conventional risk factors.

B-type natriuretic peptide in heart failure

PURPOSE OF REVIEW

This review focuses on recent literature pertaining to the role of B-type natriuretic peptide (BNP) in heart failure.

RECENT FINDINGS

Heart failure is a common disorder that is associated with significant mortality and morbidity. The diagnosis of heart failure may at times be difficult when using conventional tools. The cardiac natriuretic peptides, particularly BNP, have evolved to be useful biomarkers in heart failure and other cardiovascular disorders. Recent studies have established a close association between plasma BNP and the amino-terminal fragment of the BNP prohormone (NT-proBNP) with the diagnosis of heart failure and independent prediction of mortality and heart failure events. Furthermore, preliminary data from randomized controlled trials suggest that knowledge of BNP and/or NT-proBNP level may optimize the management of patients with heart failure. Exogenous natriuretic peptide in the form of recombinant human BNP (nesiritide) has been shown to improve hemodynamics and dyspnea and is approved in the USA and several other countries for the management of patients with acute decompensated heart failure. The effect of nesiritide on clinical outcome, however, remains unclear.

SUMMARY

When used in the appropriate clinical settings, BNP or NT-proBNP testing is extremely useful in establishing diagnosis and predicting prognosis in heart failure. Nesiritide holds promise in the management of patients with acute decompensated heart failure. Large-scale randomized controlled trials to evaluate BNP/NT-proBNP-guided therapy are currently in progress and studies of the impact of exogenous BNP on clinical outcomes in heart failure are likely to be forthcoming.

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.

Elevated plasma levels of N-terminal pro-brain natriuretic peptide in patients with chronic hepatitis C during interferon-based antiviral therapy

AIM: To investigate plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), an established marker of cardiac function, in patients with chronic hepatitis C during interferon-based antiviral therapy.

METHODS: Using a sandwich immunoassay, plasma levels of NT-proBNP were determined in 48 patients with chronic hepatitis C at baseline, wk 24 and 48 during antiviral therapy and at wk 72 during follow-up.

RESULTS: Plasma NT-proBNP concentrations were significantly increased (P < 0.05) at wk 24, 48 and 72 compared to the baseline values. NT-proBNP concentrations at baseline and wk 24 were closely correlated (r = 0.8; P < 0.001). At wk 24, 7 (14.6%) patients had NT-proBNP concentrations above 200 ng/L compared to 1 (2%) patient at baseline (P = 0.059). Six of these 7 patients had been treated with high-dose IFN-α induction therapy. In multiple regression analysis, NT-proBNP was not related to other clinical parameters, biochemical parameters of liver disease or virus load and response to therapy.

CONCLUSION: Elevated levels of NT-proBNP during and after interferon-based antiviral therapy of chronic hepatitis C may indicate the presence of cardiac dysfunction, which may contribute to the clinical symptoms observed in patients during therapy. Plasma levels of NT-proBNP may be used as a diagnostic tool and for guiding therapy in patients during interferon-based antiviral therapy.

Depression, physical impairment, and treatment of depression in chronic heart failure

BACKGROUND AND RESEARCH OBJECTIVE

This study examines the contribution of attitudes about impairment to the relation between depression and physical impairment in patients with heart failure. It also describes the current status of antidepressant treatment in a sample of outpatients with heart failure.

SUBJECTS AND METHODS

A total of 32 depressed and 51 nondepressed patients with heart failure were recruited while seeking heart failure treatment in an outpatient heart failure or family practice clinic. Medical, functional, cognitive, and psychological measures were administered at baseline. Depression measures were readministered to the 32 depressed patients at 8, 16, and 24 weeks after the baseline interview.

RESULTS AND CONCLUSIONS

Attitudes about impairment and perceived social support were the strongest cross-sectional correlates of depression. The strong association between physical impairment and depression was no longer significant after controlling for attitudes about impairment. In addition, attitudes about impairment predicted chronicity of depressive symptoms longitudinally after controlling for baseline depressive symptom severity. The relation between physical impairment and depression in heart failure is strongly related to how patients cope with impairment. These results call for the development of additional interventions to treat depression that focus on the emotional adjustment to physical impairment.

Early Activation of an Altered Thyroid Hormone Profile in Asymptomatic or Mildly Symptomatic Idiopathic Left Ventricular Dysfunction

BACKGROUND

Although an altered thyroid metabolism has been documented in patients with overt heart failure, no evaluation has been made of a heart-thyroid interaction in mildly symptomatic patients with idiopathic left ventricular dysfunction (ILVD). We wanted to assess the thyroid state in patients with ILVD.

METHODS AND RESULTS

Eighty-six patients (age 60 +/- 10 years) were enrolled into the study. Thyroxine (T4), triiodothyronine (T3), thyrotropin, brain and atrial natriuretic peptides (BNP, ANP), noradrenaline, aldosterone, renin activity, and interleukin-6 were measured. Patients were divided into three groups: Group N with LV ejection fraction (EF) > or = 50% (n = 28), Group I with LVEF > 35%-< 50% (n = 34), Group II with LVEF < or = 35% (n = 24). There was a significant correlation between T3 and LVEF (r = 0.25, P = .02) and a negative correlation between T3 and BNP (r = -0.37, P < .0001). At univariate analysis T3 was a predictor of LV dysfunction, whereas BNP was the most important predictor at multivariate analysis (P = .002). T3 was the only predictor of New York Heart Association class at multivariate analysis.

CONCLUSION

An altered thyroid profile characterized by a reduction in peripheral production of biologically active T3 is related to LV dysfunction and early symptoms of heart failure in patients with ILVD.

B-type natriuretic peptide predicts adverse cardiovascular events in pediatric outpatients with chronic left ventricular systolic dysfunction

BACKGROUND

Plasma B-type natriuretic peptide (BNP) levels are elevated in adults with heart failure and correlate with functional classification and prognosis. The range and predictive power of BNP concentrations in children with chronic heart failure, however, are not known.

METHODS AND RESULTS

Whole blood BNP concentrations were measured in 53 consecutive patients with chronic left ventricular (LV) systolic dysfunction (biventricular hearts, ejection fraction < 50%, > 3 months since diagnosis). Children who had been hospitalized within 3 months before potential enrollment and those < 2 months or > 21 years of age were excluded. BNP concentrations were measured with the Triage assay (Biosite Diagnostics, Inc, San Diego, Calif). Echocardiographers and clinicians were blinded to BNP levels. An adverse cardiovascular event was defined as cardiac death, cardiac-related hospitalization, or listing for cardiac transplantation. The median age of patients with LV dysfunction was 9.3 years (interquartile range [IQR], 2.7 to 15.1 years). BNP levels were elevated in children with LV dysfunction compared with healthy controls (median, 78 pg/mL [IQR, 22 to 551 pg/mL] versus median, 7 pg/mL [IQR, 5 to 11 pg/mL]; P < 0.0001). Whole blood BNP concentrations were increased in patients who had a 90-day adverse cardiovascular event compared with those who did not (median, 735 pg/mL [IQR, 685 to 1510 pg/mL] versus median, 37 pg/mL [IQR, 14 to 92 pg/mL]; P < 0.001). Patients with a BNP concentration > or = 300 pg/mL were at increased risk of death, hospitalization, or listing for cardiac transplantation (adjusted hazard ratio, 63.6; P < 0.0001).

CONCLUSIONS

BNP concentrations are elevated in children with chronic LV systolic dysfunction and predict the 90-day composite end point of death, hospitalization, or listing for cardiac transplantation.

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.

Natriuretic peptides in patients with atrial fibrillation and advanced chronic heart failure: determinants and prognostic value of (NT-)ANP and (NT-pro)BNP

AIMS

To study the determinants of natriuretic peptides in advanced chronic heart failure (CHF) patients with and without atrial fibrillation (AF) and to evaluate the prognostic value of natriuretic peptides in AF compared with sinus rhythm patients with advanced CHF.

METHODS AND RESULTS

The study group comprised 354 advanced CHF patients [all New York Heart Association (NYHA) III/IV], including 76 AF patients. AF patients were older (70+/-7 vs. 67+/-8; P=0.01), and non-ischaemic CHF was more common (42 vs. 19%; P=0.002) than in sinus rhythm patients, but left-ventricular ejection fraction was comparable (0.23+/-0.08 vs. 0.24+/-0.07; P=ns). At baseline, (NT-)ANP and NT-proBNP levels were significantly higher in AF patients, compared with those in sinus rhythm. By multivariate regression analysis, AF was identified as independent determinant of (NT-)ANP, but not of (NT-pro)BNP levels. After a mean follow-up of 3.2+/-0.9 (range 0.4-5.4) years, cardiovascular mortality was comparable (55 vs. 47%; P=ns). In both groups, AF and sinus rhythm, NT-proBNP [AF: adjusted HR 5.8 (1.3-25.4), P=0.02; sinus rhythm: adjusted HR 3.1 (1.7-5.7), P<0.001] was an independent risk indicator of cardiovascular mortality.

CONCLUSION

In advanced CHF patients, AF affects (NT-)ANP levels, but not (NT-pro)BNP levels. NT-proBNP is an independent determinant of prognosis in advanced CHF, irrespective of the rhythm, AF, or sinus rhythm.

[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.

Discordant Regulation of CRP and NT-proBNP Plasma Levels After Electrical Cardioversion of Persistent Atrial Fibrillation

BACKGROUND

B-type natriuretic peptide (BNP) and C-reactive protein (CRP) have been suggested to be prognostically relevant markers in patients with cardiovascular disease. Additionally, BNP and CRP plasma levels seem to be independently elevated in patients with atrial fibrillation (AF). However, there are only sparse data about the significance and temporal course of these plasma markers after restoration of sinus rhythm (SR).

METHODS

We performed a prospective study in consecutive patients with symptomatic atrial fibrillation. NT-proBNP and CRP plasma levels were measured before and one month after electrical cardioversion (CV). Patients with infections, an acute coronary syndrome, or surgery 4 weeks prior to CV, were excluded.

RESULT

Twenty-five patients (men 84%, age 66 +/- 8 years, duration of AF 90 +/- 75 days, left ventricular ejection fraction 0.57 +/- 0.11) were analyzed. At follow-up (33 +/- 6 days after CV) 14 patients (56%) were in SR and 11 patients (44%) in AF. In patients with SR there was a significant reduction of NT-proBNP levels (baseline 1647 +/- 1272 pg/mL, follow-up 772 +/- 866 pg/mL, P < 0.05), even in a subgroup of patients (n = 10) with normal left ventricular ejection fraction (1262 +/- 538 vs 413 +/- 344 pg/mL, P < 0.001). CRP levels in patients with SR were similar at baseline and at follow-up (3.5 +/- 3.6 vs 3.2 +/- 2.5 mg/L, P = 0.8).

CONCLUSION

We conclude that even in patients with normal left ventricular ejection fraction restoration of sinus rhythm leads to a significant reduction of NT-proBNP plasma levels. In contrast, CRP plasma levels seem not to be influenced during the first 4 weeks after electrical cardioversion.

Role of N-terminal brain natriuretic peptide (N-TproBNP) in scleroderma-associated pulmonary arterial hypertension

AIMS

The aims of this study were to evaluate the diagnostic value and to explore the prognostic value of N-terminal brain natriuretic peptide (N-TproBNP) in patients with systemic sclerosis (SSc) both with and without pulmonary arterial hypertension (PAH).

METHODS AND RESULTS

N-TproBNP, six-minute walk distance (SMWD), haemodynamics (at right heart catheterization) or tricuspid gradient (by echocardiography), and survival were assessed in 109 patients with SSc. The study population included 68 individuals with PAH [mean pulmonary artery pressure (PAP) >25 mmHg and pulmonary capillary wedge pressure <15 mmHg] and 41 individuals without PAH. In patients with PAH, the prognostic value of baseline and change in WHO functional class, N-TproBNP levels, and SMWD were compared using Kaplan-Meier survival curves and Cox proportional hazard analysis. The mean duration of follow-up was 10 months (range 1-18 months). One year survival in patients with normal PAP was 100% when compared with 83.5% in those with SSc-PAH (P < 0.05). The patients without PAH had a mean N-TproBNP level of 139 pg/mL (SD 151); those with SSc-PAH had a significantly higher mean N-TproBNP level of 1474 pg/mL (SD 2642) (P = 0.0002). Among patients with PAH for every order of magnitude increase in N-TproBNP level there was a four-fold increased risk of death (P = 0.002 for baseline level and P = 0.006 for follow-up level). Baseline N-TproBNP levels were correlated positively with mean PAP (r = 0.62; P < 0.0001), pulmonary vascular resistance (PVR) (r = 0.81; P < 0.0001), and inversely with SMWD (r = -0.46; P < 0.0001). Among patients with SSc-PAH, 13 patients (19%) were in WHO functional classes II and had mean N-TproBNP levels of 325 pg/mL (SD 388). Fifty-three patients (78%) were in WHO classes III and IV and had significantly higher mean N-TproBNP levels of 1677 pg/mL (SD 2835) (P = 0.02). At an N-TproBNP level of 395 pg/mL, the sensitivity and specificity for predicting the presence of SSc-PAH were 56 and 95% respectively.

CONCLUSION

Raised N-TproBNP levels are directly related to the severity of PAH. In screening programs, SSc patients with an N-TproBNP in excess of 395 pg/mL have a very high probability of having pulmonary hypertension. Baseline and serial changes in N-TproBNP levels are highly predictive of survival. A 10-fold increase in N-TproBNP level on therapy is associated with a greater than three-fold increase in mortality, and may indicate therapeutic failure.

Nonheart failure-associated elevation of amino terminal pro-brain natriuretic peptide in the setting of sepsis

In addition to its importance in clinical assessment, N-terminal pro-brain natriuretic peptide (NT pro-BNP) is a valuable marker for evaluation of treatment and prognosis of heart failure. However, there are situations where NT pro-BNP is not related to myocardial dysfunction. Two cases of sepsis with markedly elevated NT pro-BNP levels that are not indicative of depressed myocardial function are described.

Brain natriuretic peptide and cardiac autonomic function in type 2 diabetic patients

The present study tested the hypothesis that increased plasma brain natriuretic peptide (BNP) levels are related to cardiac autonomic dysfunction in type 2 diabetic patients. A total of 32 consecutive Japanese patients with type 2 diabetes were assigned to either a high-BNP (>or=18 pg/ml) group (n=12; age 57+/-13 years, mean+/-S.D.) or a normal-BNP (<18 pg/ml) group (n=20; 59+/-10 years). No patient had any overt structural heart disease. Cardiac autonomic function was assessed by measurements of baroreflex sensitivity (BRS), heart rate variability (HRV) and cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigraphic findings. BRS was lower (p<0.005) in the high-BNP group than in the normal-BNP group. However, the components of HRV, and the early and delayed myocardial uptake of (123)I-MIBG and percentage washout rate of (123)I-MIBG were not significantly different between the groups. The plasma level of BNP negatively correlated with BRS (r=0.35, p=0.049). These findings suggest that increased plasma BNP levels were related to cardiac reflex parasympathetic dysfunction in our Japanese type 2 diabetic patients.

B-type natriuretic peptide and amino terminal proBNP predict one-year mortality in short of breath patients independently of the baseline diagnosis of acute destabilized heart failure

BACKGROUND

The aim of the present study was to demonstrate the capability of B-type natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) as prognostic markers in patients with dyspnoea as a chief complaint.

METHODS

BNP and NT-proBNP plasma concentrations were obtained from 251 short of breath patients presenting to the emergency department of a tertiary care hospital. Patients with acute coronary syndromes or trauma were excluded. The endpoint was defined as all-cause mortality, and the study participants were followed up for 365 days from the time they attended the emergency department.

RESULTS

Of the 251 patients, 62 died and 189 stayed alive during follow-up. In the present study, optimal cut off levels for the prediction of survival were 454 ng/L for BNP, and 2060 ng/L for NT-proBNP. Mortality was higher in patients with baseline BNP and NT-proBNP concentrations above these cut off levels (log rank p<0.001; hazard ratios, 0.325 and 0.357, respectively). In multivariate Cox proportional-hazards regression analyses, elevated BNP/NT-proBNP, low systolic blood pressure, and renal dysfunction were predictors of mortality even when the baseline diagnosis of acute destabilized heart failure was factored into the model.

CONCLUSIONS

Both BNP and NT-proBNP measures obtained from short of breath patients presenting to an emergency department may be predictive of one-year all-cause mortality independently of the baseline diagnosis of acute destabilized heart failure.

NT-proBNP levels, echocardiographic findings, and outcomes in breathless patients: results from the ProBNP Investigation of Dyspnoea in the Emergency Department (PRIDE) echocardiographic substudy

AIMS

The objective of this study was to determine the integrative utility of measuring plasma NT-proBNP levels with echocardiography in the evaluation of dyspnoeic patients.

METHODS AND RESULTS

Of 599 emergency department patients enrolled in a clinical study of NT-proBNP at a tertiary-care hospital, 134 (22%) had echocardiographic results available for analysis. Echocardiographic parameters correlating with NT-proBNP levels were determined using multivariable linear-regression analysis. Independent predictors of 1-year mortality were determined using Cox-proportional hazard analysis. Independent relationships were found between NT-proBNP levels and ejection fraction (P = 0.012), tissue Doppler early and late mitral annular diastolic velocities (P = 0.007 and 0.018), right ventricular (RV) hypokinesis (P = 0.006), and tricuspid regurgitation severity (P < 0.001) and velocity (P = 0.007). An NT-proBNP level <300 pg/mL had a negative predictive value of 91% for significant left ventricular systolic and diastolic dysfunction. Overall 1-year mortality was 20.1% and was independently predicted by NT-proBNP level [HR 8.65, 95% confidence interval (CI) 2.7-27.8, P = 0.0003], ejection fraction (HR 0.95, 95% CI 0.91-0.99, P = 0.009), RV dilation (HR 2.98, 95% CI 1.05-12.8, P = 0.04), and systolic blood pressure (HR 0.97, 95% CI 0.96-0.99, P = 0.01).

CONCLUSION

NT-proBNP levels correlate with, and provide important prognostic information beyond, echocardiographic parameters of cardiac structure and function. Routine NT-proBNP testing may thus be useful to triage patients to more timely or deferred echocardiographic evaluation.

The value of cardiopulmonary exercise testing and brain natriuretic peptide plasma levels in predicting the prognosis of patients with chronic heart failure

BACKGROUND

A peak VO2 above 14 ml/min/kg at cardiopulmonary exercise testing and brain natriuretic peptide (BNP) levels is used to estimate survival in patients with chronic heart failure (CHF). Limited data, however, exist comparing the prognostic value of both markers simultaneously in patients with mild to moderate CHF.

METHODS

We prospectively studied 85 consecutive patients (59+/-13 years, 63 men) with CHF (mean LVEF 26+/-6%). All patients underwent cardiopulmonary exercise testing with determination of peak VO2 and measurement of plasma BNP at rest. The incidence of cardiac decompensation and cardiac death was recorded in the follow-up.

RESULTS

During a mean follow-up of 427+/-150 days, four deaths and ten cardiac decompensations occurred. Kaplan-Meier estimates of freedom from clinical events differed significantly for patients above and below the median BNP of 292 pg/ml and also for patients above and below a peak VO2 of 14 ml/min/kg (p<0.05 each). BNP and peak VO2 (area under the ROC 0.75 vs. 0.72) showed a comparable discrimination of CHF patients with adverse cardiac events. The prognostic information of BNP was at least as powerful as that derived from peak VO2. A BNP above 324 pg/ml was associated with a risk ratio of 8.8 for adverse cardiac events.

CONCLUSIONS

In patients with mild to moderate CHF, BNP measurements appear to be an alternative to peak VO2 determined by cardiopulmonary exercise testing for the assessment of prognosis in CHF. BNP may facilitate the ambulatory management of patients with mild to moderate CHF since it is less expensive, less time-consuming, and free of procedural risk compared to exercise testing.

Circulating levels of myocardial proteins predict future deterioration of congestive heart failure

BACKGROUND

This study was designed to test whether circulating levels of myocardium-specific proteins serve as useful markers for the prognosis of patients with congestive heart failure.

METHODS AND RESULTS

Seventy-eight patients with congestive heart failure from dilated cardiomyopathy but in a stable condition were enrolled, and their blood was sampled for measurements of myosin light chain-I (MLC-I), troponin T (TnT), heart fatty-acid-binding protein (H-FABP), and creatine kinase isoenzyme MB (CK-MB). The patients were then followed up for 951 +/- 68 days, with the endpoint being acute deterioration. A univariate analysis revealed that MLC-I, TnT, H-FABP, and CK-MB were significant predictors for acute deterioration of heart failure. Application of the Kaplan-Meier method using cutoff values determined by analysis of receiver operating characteristics curves demonstrated that the incidence of acute deterioration was significantly higher in patients with higher values of MLC-I (61.9%), TnT (52.4%), H-FABP (50.0%), or CK-MB (38.6%) than in those with lower values of these markers (15.8%, 20.4%, 13.6%, and 16.1%, respectively).

CONCLUSIONS

Increased circulating levels of the specific myocardial proteins are related to a higher probability of future acute deterioration of congestive heart failure in patients in a stable condition associated with dilated cardiomyopathy.

B-type natriuretic peptide levels in obese patients with advanced heart failure

Although recent studies show that obesity, or elevated body mass index (BMI), is associated with lower levels of B-type natriuretic peptide (BNP), it is unknown whether BMI affects the prognostic value of BNP in heart failure (HF). This study confirms the relationship between high BMI and low BNP in patients with advanced systolic HF. Despite relatively lower levels of BNP in overweight and obesity, BNP predicts worse symptoms, impaired hemodynamics, and higher mortality in HF at all levels of BMI.

OBJECTIVES

This study aimed to examine the influence of obesity on the predictive value of the B-type natriuretic peptide (BNP) assay in heart failure (HF).

BACKGROUND

Recent studies show that obesity, or elevated body mass index (BMI), is associated with lower circulating levels of BNP both in the general population and in patients with HF.

METHODS

We analyzed data from 316 systolic HF (left ventricular ejection fraction [LVEF] < or =40%) patients [age, 53 +/- 13 years; mean LVEF, 24 +/- 7%; 48% ischemic] followed up at a university HF center. Patients were divided into categories of BMI: lean (BMI <25 kg/m2), overweight (BMI = 25 to 29.9 kg/m2), and obese (BMI > or =30 kg/m2).

RESULTS

The BNP levels were significantly lower in overweight and obese compared with lean patients (p = 0.0001); median BNP (interquartile range) for the lean (n = 131), overweight (n = 99), and obese (n = 86) groups was 747 (272 to 1,300), 380 (143 to 856), and 332 (118 to 617) pg/ml, respectively. In each BMI category, elevated BNP was significantly associated with worse symptoms and higher pulmonary capillary wedge pressure. Higher BNP was also a significant independent predictor of survival independent of BMI. Optimal BNP cutoff for prediction of death or urgent transplant in lean, overweight, and obese HF patients was 590, 471, and 342 pg/ml, respectively.

CONCLUSIONS

Although BNP levels are relatively lower in overweight and obese HF patients, BNP predicts worse symptoms, impaired hemodynamics, and higher mortality at all levels of BMI.

Amino-Terminal Pro-Brain Natriuretic Peptide Predicts Ventricular Arrhythmogenesis in Patients With Ischemic Cardiomyopathy and Implantable Cardioverter-Defibrillators

STUDY OBJECTIVES

Even in high-risk population groups, not all patients have the same risk of sudden cardiac death (SCD). Given the emerging data about the amino-terminal fragment of the brain natriuretic peptide prohormone (NT-proBNP) value in heart failure, we planned to evaluate the importance of NT-proBNP levels in predicting the occurrence of malignant arrhythmias in patients with ischemic cardiomyopathy and implantable cardioverter-defibrillators (ICDs).

DESIGN

Prospective study.

SETTING

Tertiary referral center.

PATIENTS

Thirty five ambulatory patients with previous myocardial infarction, left ventricular ejection fraction < 35%, and ICDs for primary prevention of SCD according to Multicenter Automatic Defibrillator Implantation Trial I criteria.

INTERVENTIONS

Venous blood samples for plasma NT-proBNP measurement were obtained after 30 min of supine rest from all patients at the beginning of the study. Patients were evaluated every 2 months, or sooner in cases of device discharges, during a 1-year follow-up period. Data concerning arrhythmias and device therapy were stored at the time of device interrogation on each follow-up visit.

MEASUREMENTS AND RESULTS

During 1-year follow-up, 11 of 35 patients (31.4%) received 18 antiarrhythmic device therapies for ventricular tachyarrhythmia (VT). Patients who experienced such arrhythmias had NT-proBNP levels of 997.27 +/- 335.14 pmol/L (mean +/- SD), whereas those without VT had NT-proBNP levels of 654.87 +/- 237.87 pmol/L (p = 0.001). An NT-proBNP cutoff value of 880 pmol/L had a sensitivity of 73%, a specificity of 88%, a positive predictive value of 80%, and a negative predictive value of 88% for the prediction of occurrence-sustained VT events.

CONCLUSION

To achieve the maximum benefit by ICD therapy, more precise risk stratification is required, even in high-risk, post-myocardial infarction patients. Plasma NT-proBNP levels comprise a promising method that could help in the better identification of a patient group with an even higher risk of sudden death.

Lower rather than higher levels of B-type natriuretic peptides (NT-pro-BNP and BNP) predict short-term mortality in end-stage heart failure patients treated with nesiritide

Elevated plasma natriuretic peptides in heart failure (HF) usually indicate a poor outcome and low levels a compensated state. In advanced chronic HF, however, low levels may reflect an impaired neurohormonal response. To assess this hypothesis, this study analyzed whether N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP) and B-type natriuretic peptide (BNP) levels were related to mortality in 40 patients treated for decompensated chronic HF. Cardiovascular mortality during follow-up (10 +/- 1 months) was 40%. BNP levels were lower in patients who died (487 +/- 60 vs 836 +/- 99 pg/ml, p <0.02), as were NT-pro-BNP levels (9,507 +/- 1,178 vs 17,611 +/- 4,338 pg/ml, p <0.05). These data support the hypothesis that patients with end-stage HF and poor short-term survival have lower natriuretic peptide levels than those who survive. These findings suggest that the natriuretic peptide system can no longer contribute adequately to neurohormonal compensation and that paradoxically low peptide levels are an adverse prognostic marker in advanced HF.

Relation of age, severity of illness, and hemodynamics with brain natriuretic peptide levels in patients <20 years of age with heart disease

Brain natriuretic peptide (BNP) levels were obtained before cardiac catheterization in 193 pediatric patients with a variety of cardiac lesions. Age and functional status had strong relations to BNP values, with elevations of BNP levels associated with increasing functional disability and decreasing age. Mild but statistically significant correlations were found between BNP levels and right-sided cardiac pressures. In patients with volume-overloaded ventricles, BNP correlated with the degree of overcirculation.

Exercise duration and peak systolic blood pressure are predictive of mortality in ambulatory patients with mild-moderate chronic heart failure

BACKGROUND AND AIMS

It is a prevailing concept in chronic heart failure (CHF) that ventricular remodelling (evaluated via imaging) and neurohormonal activation (via biomarkers) exert major influences, such that the need to subject patients to haemodynamic evaluations and exercise testing has been questioned. We sought to investigate whether exercise and haemodynamic parameters lack independent prognostic value in a cohort of unselected ambulatory patients with mild-moderate CHF.

METHODS

Eighty-five consecutive patients with stable CHF in New York Heart Association functional classes I-IV, aged 55 +/- 12 years, 84% males, left ventricular ejection fraction (LVEF) 37 +/- 15%, participated in this study. Survivors were followed for a median of 5.08 years. All subjects underwent cardiopulmonary exercise testing to measure standard parameters including peak oxygen consumption, exercise duration and blood pressure. A sample of venous blood was taken to determine the N-terminal pro-brain natriuretic peptide (N-BNP) level. Echocardiography was performed at rest to measure LVEF. Predictors of mortality were sought using the Cox proportional hazards model.

RESULTS

All-cause mortality was 19% (16 deaths, 95% CI 11-29%). Age and LVEF did not independently predict mortality. Although various parameters including New York Heart Association class, peak oxygen consumption and N-BNP level were all predictive of outcome on univariate analysis, multivariate analysis identified reduced exercise duration and peak systolic blood pressure (SBP) to be the only independent predictors of all-cause mortality. Hazard ratios of 0.78 (95% CI 0.65-0.93, p = 0.007) and 0.79 (95% CI 0.66-0.95, p = 0.01) were associated with an increase in exercise duration of 1 min and 10 mm Hg peak SBP, respectively.

CONCLUSIONS

Two simple parameters (exercise duration and peak SBP) that are easily measured by standard exercise testing are the strongest independent predictors of mortality which outperform LVEF and N-BNP in ambulatory patients with mild-moderate CHF.