Plasma N-terminal pro-brain natriuretic peptide and the ECG in the assessment of left-ventricular systolic dysfunction in a high risk population

A New Hematocrit Measurement Method Using a Chemiluminescence Biosensor and Its Application in a Chemiluminescence Immunoassay Platform for Myocardial Markers Detection with Whole Blood Samples

The accuracy and precision of analyte concentrations measured in whole blood by chemiluminescence immunoassay (CLIA) have been significantly affected by erythrocytes, which leads to poor application of whole blood CLIA in clinical practice. In this work, a chemiluminescence biosensing optical platform for blood hematocrit (HCT) analysis using MAGICL 6000 (Getein Biotechnology, Nanjing, China) was designed, implemented, and fully characterized. The developed method was successfully applied to determine various HCT levels of human blood from 0% to 65%, with a correlation coefficient of 0.9885 compared with the conventional method (Sysmex XE 5000, Kobe, Japan). A mathematical model was developed to quantitatively evaluate the impact of HCT on the results of two sample types (whole blood vs. plasma). Combining the established HCT method and mathematical model with CLIA on MAGICL 6000, the precision was significantly improved by almost 20%. Comparison studies using whole blood samples and corresponding plasma samples showed that the square of the correlation coefficients of troponin I (cTnI), myoglobin (MYO), creatine kinase MB (CK-MB), and N-terminal pro-hormone brain natriuretic peptide (NT-proBNP) were increased to 0.9992, 0.9997, 0.9996, and 0.9994, respectively, showing a great potential for clinical application.

Amino-terminal pro-brain natriuretic peptide: a biomarker for diagnosis, prognosis and management of heart failure

There is a substantial need for a diagnostic tool to aid in the early diagnosis of heart failure and in the recognition of those at risk for its development, as well as in guidance of therapy. Testing for amino-terminal pro-brain natriuretic peptide (NT-proBNP) has been recognized to have utility in the diagnosis, prognosis and management of heart failure. In addition, numerous other applications for NT-proBNP testing are now recognized, such as evaluation of patients with heart disease in the absence of heart failure, as well as the diagnostic and prognostic evaluation of patients with acute coronary syndromes or pulmonary thromboembolism.

Analysis of the severity and prognosis assessment of aged patients with community-acquired pneumonia: a retrospective study

BACKGROUND

Community-acquired pneumonia (CAP) is a prevalent and potentially life-threatening infection, and has poor prognosis in aged patients. The objective of this study was to compare the potential of admission N-terminal pro B-type natriuretic peptide (proBNP) levels and scoring models [CURB-65, Pneumonia Severity Index (PSI), and Acute Physiology and Chronic Health Evaluation (APACHE) II scores] to predict outcomes for aged patients with CAP admitted to Intensive Care Unit (ICU), and to explore the prognostic factors.

METHODS

Clinical data of the patients were collected retrospectively, whose CURB-65, PSI, APACHE II scores were calculated and in whom measurements of proBNP was performed. The outcomes of interest were severity evaluation, prediction of need for mechanical ventilation and 28-day mortality. Receiver operating characteristic (ROC) curve was conducted to predict the assessment ability of proBNP and scoring models on different outcomes, and the logistic regression analysis was performed to screen factors affecting prognosis.

RESULTS

240 patients were enrolled, with the mean age of 75±8 years old. Admission levels of NT-proBNP, scoring models were significantly higher in SCAP patients, MV group, and non-survivors compared to non-SCAP patients, no-MV group, and 28-day survivors, respectively (P<0.001). PSI had the highest area under the curve (AUC) and specificity for the three outcomes considered (AUC: 0.868 and specificity: 0.906 for 28-day mortality, AUC: 0.864 and specificity: 0.831 for requirement of MV, and AUC: 0.888 and specificity: 0.894 for severity evaluation). NT-proBNP had the highest sensitivity of 0.987 and 0.903 on prediction of mortality and need for MV. And APACHE II scoring model with the highest sensitivity of 0.890 was used to evaluate severity. Logistic regression analysis showed that the odd ratio (OR) of systolic blood pressure, PSI, and APACHE II scores were 0.886, 1.019, and 1.249.

CONCLUSIONS

PSI scores was the best indicator in predicting different clinical outcomes of aged patients with CAP among the proBNP and three scoring systems. Systolic blood pressure might be as a protective factor for prognosis while PSI and APACHE II scores as risk factors for prognosis of aged patients with CAP.

Plasma N-terminal pro-B-type natriuretic peptide is predictive of perioperative cardiac events in patients undergoing vascular surgery

BACKGROUND/AIMS

Identification of patients at high risk for perioperative cardiac events (POCE) is clinically important. This study aimed to determine whether preoperative measurement of plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) could predict POCE, and compared its predictive value with that of conventional cardiac risk factors and stress thallium scans in patients undergoing vascular surgery.

METHODS

Patients scheduled for non-cardiac vascular surgery were prospectively enrolled. Clinical risk factors were identified, and NT-proBNP levels and stress thallium scans were obtained. POCE was the composite of acute myocardial infarction, congestive heart failure including acute pulmonary edema, and primary cardiac death within 5 days after surgery. A modified Revised Cardiac Risk Index (RCRI) was proposed and compared with NT-proBNP; a positive result for ischemia and a significant perfusion defect (≥ 3 walls, moderate to severely decreased, reversible perfusion defect) on the thallium scan were added to the RCRI.

RESULTS

A total of 365 patients (91% males) with a mean age of 67 years had a median NT-proBNP level of 105.1 pg/mL (range of quartile, 50.9 to 301.9). POCE occurred in 49 (13.4%) patients. After adjustment for confounders, an NT-proBNP level of > 302 pg/mL (odds ratio [OR], 5.7; 95% confidence interval [CI], 3.1 to 10.3; p < 0.001) and a high risk by the modified RCRI (OR, 3.9; 95% CI, 1.6 to 9.3; p = 0.002) were independent predictors for POCE. Comparison of the area under the curves for predicting POCE showed no statistical differences between NT-proBNP and RCRI.

CONCLUSIONS

Preoperative measurement of NT-proBNP provides information useful for prediction of POCE as a single parameter in high-risk patients undergoing noncardiac vascular surgery.

Sensitivity and specificity of NT-proBNP to detect heart failure at post mortem examination

NT-proBNP, a marker of cardiac failure, has been shown to be stable in post mortem samples. The aim of this study was to assess the accuracy of NT-proBNP to detect heart failure in the forensic setting. One hundred sixty-eight consecutive autopsies were included in the study. NT-proBNP blood concentrations were measured using a chemiluminescent immunoassay kit. Cardiac failure was assessed by three independent forensic experts using macro- and microscopic findings complemented by information about the circumstances of body discovery and the known medical story. Area under the receiving operator curve was of 65.4% (CI 95%, from 57.1 to 73.7). Using a standard cut-off value of >220 pg/mL for NT-proBNP blood concentration, heart failure was detected with a sensitivity of 50.7% and a specificity of 72.6%. NT-proBNP vitreous humor values were well correlated to the ones measured in blood (r (2) = 0.658). Our results showed that NT-proBNP can corroborate the pathological findings in cases of natural death related to heart failure, thus, keeping its diagnostic properties passing from the ante mortem to the post mortem setting. Therefore, biologically inactive polypeptides like NT-proBNP seem to be stable enough to be used in forensic medicine as markers of cardiac failure, taking into account the sensitivity and specificity of the test.

Signal-enhancer molecules encapsulated liposome as a valuable sensing and amplification platform combining the aptasensor for ultrasensitive ECL immunoassay

An innovatory ECL immunoassay strategy was proposed to detect the newly developing heart failure biomarker N-terminal pro-brain natriuretic peptide (NT-proBNP). Firstly, this strategy used small molecules encapsulated liposome as immune label to construct a sandwich immune sensing platform for NT-proBNP. Then the ECL aptasensor was prepared to collect and detect the small molecules released from the liposome. Finally, based on the ECL signal changes caused by the small molecules, the ECL signal indirectly reflected the level of NT-proBNP antigen. In this experiment, the cocaine was chosen as the proper small molecule that can act as signal-enhancer to enhance the ECL of Ru(bpy)(3)(2+). The cocaine-encapsulated liposomes were successfully characterized by TEM. The quantificational calculation proved the ∼5.3×10(3) cocaine molecules per liposome enough to perform the assignment of signal amplification. The cocaine-binding ECL aptasensor further promoted the work aimed at amplifying signal. The performance of NT-proBNP assay by the proposed strategy exhibited high sensitivity and high specificities with a linear relationship over 0.01-500 ng mL(-1) range, and a detection limit down to 0.77 pg mL(-1).

N-Terminal Pro-B-type Natriuretic Peptide Is Useful to Predict Cardiac Complications Following Lung Resection Surgery

Background

Cardiovascular complications are major causes of morbidity and mortality following non-cardiac thoracic operations. Recent studies have demonstrated that elevation of N-Terminal Pro-B-type natriuretic peptide (NT-proBNP) levels can predict cardiac complications following non-cardiac major surgery as well as cardiac surgery. However, there is little information on the correlation between lung resection surgery and NT-proBNP levels. We evaluated the role of NT-proBNP as a potential marker for the risk stratification of cardiac complications following lung resection surgery.

Material and Methods

Prospectively collected data of 98 patients, who underwent elective lung resection from August 2007 to February 2008, were analyzed. Postoperative adverse cardiac events were categorized as myocardial injury, ECG evidence of ischemia or arrhythmia, heart failure, or cardiac death.

Results

Postoperative cardiac complications were documented in 9 patients (9/98, 9.2%): Atrial fibrillation in 3, ECG-evidenced ischemia in 2 and heart failure in 4. Preoperative median NT-proBNP levels was significantly higher in patients who developed postoperative cardiac complications than in the rest (200.2 ng/L versus 45.0 ng/L, p=0.009). NT-proBNP levels predicted adverse cardiac events with an area under the receiver operating characteristic curve of 0.76 [95% confidence interval (CI) 0.545~0.988, p=0.01]. A preoperative NT-proBNP value of 160 ng/L was found to be the best cut-off value for detecting postoperative cardiac complication with a positive predictive value of 0.857 and a negative predictive value of 0.978. Other factors related to cardiac complications by univariate analysis were a higher American Society of Anesthesiologists grade, a higher NYHA functional class and a history of hypertension. In multivariate analysis, however, high preoperative NT-proBNP level (>160 ng/L) only remained significant.

Conclusion

An elevated preoperative NT-proBNP level is identified as an independent predictor of cardiac complications following lung resection surgery.

Value of N-terminal brain natriuretic peptide as a prognostic marker in patients with CKD: results from the CREATE study

BACKGROUND AND OBJECTIVES

This study assessed plasma N-terminal prohormone brain natriuretic peptide (NT-proBNP) as a prognostic marker of cardiovascular risk in patients with chronic kidney disease stages 3-4 and anaemia treated with epoetin beta to two haemoglobin target ranges.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

Of 603 patients enrolled in the Cardiovascular Risk Reduction by Early Anaemia Treatment with Epoetin Beta (CREATE) trial (baseline creatinine clearance 15-35 mL/min; haemoglobin 11.0-12.5 g/dL), 291 were included in this sub-study. Patients received subcutaneous epoetin beta either immediately after randomisation (target 13.0-15.0 g/dL; Group 1), or after their haemoglobin levels had fallen < 10.5 g/dL (target 10.5-11.5 g/dL; Group 2). Chronic heart failure New York Heart Association class III-IV was an exclusion criterion. (ClinicalTrials.gov Identifier: NCT00321919)

RESULTS

Cardiovascular event rates were higher in patients with baseline NT-proBNP > 400 vs. ≤ 400 pg/mL (39 vs. 13 events; p = 0.0002). Dialysis was initiated in 68 vs. 42 patients with NT-proBNP > 400 vs. ≤ 400 pg/mL (p = 0.0003). Amongst patients with NT-proBNP > 400 pg/mL, there was no significant difference between treatment groups in risk of cardiovascular events (HR = 0.57; p = 0.08) or time to dialysis (HR = 0.65; p = 0.08). The overall interpretation of this substudy is, however, limited by its relatively small sample size which, together with low clinical event rates, result in a lack of statistical power for some analyses and should be viewed as being hypothesis-generating in nature.

CONCLUSIONS

In chronic kidney disease patients with mild-to-moderate anaemia, elevated baseline plasma NT-proBNP levels are associated with a higher risk of cardiovascular events and an accelerated progression towards end-stage renal disease.

NT‐ProBNP serum levels reflect severity and extent of ischemia in patients admitted with non‐ST‐elevation acute coronary syndrome

OBJECTIVE

To explore the relationship between NT-proBNP elevation and prognosis in patients with NSTEACS.

BACKGROUND

High NT-proBNP levels are related to a worse prognosis in patients with ACS. The precise mechanism by which is not clear.

METHODS

Serial sampling of NT-proBNP, Troponin T and CK-MB was performed in 23 patients admitted with NSTEACS. Using coronary angiography in each patient a culprit lesion was identified. Proximal lesions were located before or at the first major branch of the parent artery. All other lesions localizations were considered distal. To evaluate the influence of left ventricular systolic function on NT-proBNP levels WMSI was measured by echocardiography.

RESULTS

Proximal culprit lesion localization was associated with significant higher baseline (mean 506 ng/l, SD 440 ng/l) and peak NT-proBNP levels (mean 1055 ng/l; SD 236 ng/l), as compared to patients with a distal lesion localization. (Baseline: 139 ng/l, SD 140 ng/l, peak: 381 ng/l; SD 64 ng/l). (P = 0.01) NT-proBNP levels were highly correlated to Troponin T and CK-MB peak serum levels. Adjustments for left ventricular dysfunction did not alter these associations.

CONCLUSIONS

High peak NT-proBNP levels are independently associated with both proximal culprit localization and elevated biochemical markers of myocardial damage. These findings suggest that NT-proBNP levels reflect the amount of jeopardized myocardium and could signify the integral of the extent and severity of an ischemic event.

Analysis of inflammatory response and utility of N-terminal pro brain-type natriuretic peptide in cardiac surgery with extracorporeal circulation

OBJECTIVES

Cardiac surgery with cardiopulmonary bypass (CPB) elicits an inflammatory response. During and after cardiac surgery, we examined the pattern of cytokine release of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-alpha, to investigate inflammatory response. We analyzed N-terminal pro brain-type natriuretic peptide (NT-proBNP) as a marker of ventricular function.

METHODS

Consecutive patients (n = 58) undergoing elective cardiac surgery with extra-corporeal circulation were recruited into the study. Blood samples for analysis of the biochemical markers were taken at seven time points for cytokines and TNF, and three for Nt-proBNP.

RESULTS

All markers increased significantly after CPB. IL-6 and IL-8 levels were higher in men. IL-8 was related to a need for inotropic support. IL-6 was related to the time of CPB (P = 0.004), aortic clamping (P = 0.013), length of stay in intensive care unit (ICU) (P = 0.004) and mechanical ventilation for more than 12 h (P = 0.006). The levels of NT-proBNP were higher in cases of ventricular dysfunction (P = 0.003) and functional class III/IV (P = 0.001). The postoperative values were related to age (P < 0.05), creatinine values (P < 0.001), mechanical ventilation time (P < 0.001) and stay in the ICU (P = 0.001).

CONCLUSION

Our data indicate a relationship between cytokine levels and sex, time of CPB and aortic clamping, The increase of cytokines correlates with a need for inotropic support, mechanical ventilation and length of stay in ICU. We confirmed the predictive role, and its utility in the risk stratification of the NT-proBNP, and its importance in early diagnosis of postoperative ventricular dysfunction.

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.

N-terminal Pro-B-type natriuretic peptide, vascular disease risk, and cholesterol reduction among 20,536 patients in the MRC/BHF heart protection study

OBJECTIVES

We sought to assess the ability of N-terminal pro-B-type natriuretic peptide (N-BNP) to predict vascular events in high-risk people and to test whether statins benefit people with high levels of N-BNP.

BACKGROUND

The predictive value of N-BNP for occlusive vascular events and the effects of statins in people with high N-BNP levels are uncertain.

METHODS

A total of 20,536 people were assigned randomly to simvastatin 40 mg daily or placebo for an average of 5 years. Five baseline N-BNP groups were defined (<386; 386 to 1,171; 1,172 to 2,617; 2,618 to 5,758; and > or =5,759 pg/ml).

RESULTS

Baseline N-BNP was strongly predictive of future vascular events independently of other characteristics. Compared with participants with N-BNP <386 pg/ml, those with levels > or =5,759 pg/ml had adjusted relative risks for major vascular events (MVEs) (i.e., major coronary events [MCE] [nonfatal myocardial infarction or coronary death], stroke, or revascularization) of 2.26, for MCE of 3.09, for stroke of 1.80, and for heart failure (hospitalization or death) of 9.23 (all p < 0.0001). Overall, simvastatin allocation reduced the relative risk of MVE by 24% (95% confidence interval 19 to 28). There was a trend toward smaller (but still significant) proportional reductions in MVE among participants with greater baseline N-BNP levels, but the absolute benefits of simvastatin allocation were similar at all N-BNP levels. Simvastatin allocation was also associated with a 14% (95% confidence interval 0 to 25) proportional reduction in heart failure. No excess risk of other vascular and nonvascular outcomes was observed with simvastatin allocation among participants with greater baseline values of N-BNP.

CONCLUSIONS

In this study, N-BNP levels were strongly predictive not only of heart failure but also of MVEs. In people with high N-BNP levels consistent with heart failure, statin allocation significantly reduced vascular risk, with no evidence of hazard. (http://www.controlledtrials.com/ISRCTN48489393/48489393).

The Effect of Beta-Blocker (Carvedilol) Therapy on N-Terminal Pro-Brain Natriuretic Peptide Levels and Echocardiographic Findings in Patients with Congestive Heart Failure

BACKGROUND

The favorable effects of beta-blockers on decreasing mortality in contemporary heart failure management have been demonstrated in recent years. N-terminal pro-brain natriuretic (NT-proBNP) peptide levels increase in patients with heart failure. The purpose of this study was to investigate the correlation between the NT-proBNP levels and echocardiographic findings for the patients who received carvedilol therapy in addition to standard therapy for congestive heart failure.

METHODS AND RESULTS

A total of 25 patients with symptomatic congestive heart failure and 25 healthy individuals were enrolled in the study. Before introducing beta-blocker into their therapy regimens, baseline transthoracic echocardiography recordings were made and venous blood samples were drawn for establishing NT-proBNP levels. The patients were administered with a minimum dose of carvedilol. Three months after reaching the maximum tolerable dose, blood samples were drawn from the patients once again for NT-proBNP measurements, and transthoracic echocardiography was performed. There was a significant drop in plasma NT-proBNP levels at the end of the study in comparison to the baseline values (baseline: 381.20+/-35.06 pg/mL, at the end of the third month: 254.44+/-28.64 pg/mL; P < 0.001). While left ventricular end-diastolic and end-systolic diameters were observed to have significantly decreased as a result of the therapy (P < 0.001), left ventricular ejection fraction (P<0.001) was established to have increased significantly.

CONCLUSIONS

Carvedilol therapy resulted in a marked decrease in plasma NT-proBNP levels and increase left ventricular ejection fraction in patients with congestive heart failure.

B-type natriuretic peptide and N-terminal pro B-type natriuretic peptide are depressed in obesity despite higher left ventricular end diastolic pressures

BACKGROUND

B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are frequently used in diagnosing and monitoring patients with heart failure. Recent studies have demonstrated that concentrations of these peptides are decreased in obese patients, but whether lower natriuretic peptide concentrations are really due to different hemodynamics is unknown. The relationship between these markers and left ventricular end diastolic pressure (LVEDP) in obesity has not been elucidated.

METHODS

We examined patients undergoing cardiac catheterization who had creatinine of < 2.0, no evidence of myocardial infarction or pulmonary embolism, and no cardiac transplant. Body mass index and LVEDP were determined, and BNP and NT-proBNP obtained at the start of each case. Obesity was defined as body mass index of > or = 30 kg/m2.

RESULTS

Of 203 patients enrolled, 101 were obese. The groups were similar in respect to race, creatinine, cholesterol, and history of dyslipidemia and cardiomyopathy. The obese patients tended to be younger, were more likely to have diabetes and hypertension, and were less likely to have coronary artery disease. The obese patients had higher LVEDP but reduced BNP and NT-pro-BNP. The relationship between the natriuretic peptides and LVEDP was poor, with r values of < 0.1.

CONCLUSIONS

Obese patients have reduced concentrations of BNP and NT-proBNP compared to nonobese patients despite having elevated LVEDP. This suggests that factors other than cardiac status impact on BNP and NT-proBNP concentrations. The poor relationship between natriuretic peptide concentrations and LVEDP also suggests that these concentrations should not be considered surrogates for cardiac filling pressures or volumes.

Diagnostic and prognostic value of urine NT-proBNP levels in heart failure patients

BACKGROUND

Plasma NT-proBNP levels are sensitive markers of ventricular dysfunction. However, studies of natriuretic peptides in urine are limited.

AIMS

To compare urine and plasma NT-proBNP levels and to investigate the diagnostic and prognostic value of urine levels in heart failure (HF).

METHODS

Urinary and plasma NT-proBNP levels were measured in 96 HF patients and 20 control subjects. The patients were functionally classified according to the NYHA criteria.

RESULTS

Urine NT-proBNP was higher in HF patients than in control subjects (94+/-31 pg/ml vs. 67+/-6 pg/ml, p<0.0001), correlating with plasma NT-proBNP levels (r=0.78, p<0.0001). Urinary levels were elevated in the more severe functional classes and diminished in obese patients. Urine NT-proBNP was a good tool for diagnosis of HF, the area under the curve (AUC) being 0.96+/-0.02 (p<0.0001), and for predicting 12-month cardiac events (p=0.011). To determine the prognostic power of urinary NT-proBNP in detecting 12-month cardiac mortality, we obtained an AUC of 0.75+/-0.10 (p=0.015).

CONCLUSION

Urinary NT-proBNP, a relatively simple non-invasive test, is a new candidate marker for the diagnosis and evaluation of prognosis in HF and for the characterization of functional status in these patients.

Plasma homocysteine and vascular disease in psychogeriatric patients

BACKGROUND

There is a high frequency (40-50%) of elevated plasma total homocysteine (tHcy) concentrations in elderly patients with mental disorders, and patients with a history of vascular disease exhibit significantly higher plasma tHcy concentration than patients without vascular disease.

METHOD

The main objective of the present study was to further investigate the association between plasma tHcy concentration and vascular disease in psychogeriatric patients. We have therefore investigated 304 psychogeriatric patients and determined plasma tHcy and its most important determinants (folate and cobalamin status and renal function), and the natriuretic peptide N-terminal-pro brain natriuretic peptide (NT-proBNP). The patients were classified into several groups of vascular disease according to the findings of brain imaging and presence of a history/symptoms indicating manifest occlusive arteriosclerotic vascular disease.

RESULTS

Plasma tHcy concentration is associated with the presence of vascular disease in psychogeriatric patients. The presence of vascular disease is also associated with higher age, higher serum NT-proBNP, renal impairment and lower serum folate concentration than in patients without vascular disease. The significant association between plasma tHcy concentration and vascular disease remained after correction for age and for cystatin C differences between the groups of patients without and with vascular disease. In the present population with only 16% of the patients showing elevated plasma tHcy, renal function was a more important determinant for plasma tHcy concentration than folate status.

CONCLUSION

Plasma tHcy concentration is associated with vascular disease. In the present population of psychogeriatric patients renal function is associated with vascular disease and elevated plasma tHcy concentration. Thus, the association between plasma tHcy concentration and vascular disease might partially be explained by impairment of renal function.

B-Type Natriuretic Peptide and the Risk of Cardiovascular Events and Death in Patients With Stable Angina

OBJECTIVES

The aim of this study was to assess the predictive value of the cardiac hormone B-type natriuretic peptide (BNP) for long-term outcome in a large cohort of stable angina patients.

BACKGROUND

Recent data suggest a role of BNP in stable ischemic heart disease beyond its known value in heart failure and acute coronary syndromes.

METHODS

In 1,085 patients with coronary artery disease (CAD) baseline levels of BNP were prospectively associated with cardiovascular (CV) events during a mean follow-up of 2.5 years.

RESULTS

BNP concentrations were significantly elevated in patients with future CV events (median [25th/75th interquartile range] 119.2 [43.6/300.4] pg/ml vs. 36.2 [11.3/94.6] pg/ml; p < 0.001). Kaplan-Meier survival analysis showed a stepwise decrease in event-free survival across quartiles of BNP baseline concentration (p(log rank) < 0.001). Patients in the highest quartile revealed a 6.1-fold increased risk (p = 0.001) compared to patients in the lowest quartile after adjustment for potential confounders. For a cut-off value of 100 pg/ml, an independently increased risk of adverse outcome (hazard ratio [HR] 4.4; p < 0.001) could be demonstrated. One standard deviation (SD) decrease in ejection fraction implied the most prominent increase in risk of future CV events (HR 1.69; p < 0.001) followed by one SD increase in BNP (HR 1.53; p < 0.001). The highest prognostic accuracy could be demonstrated for BNP (area under the curve 0.671).

CONCLUSIONS

The data of this large group of CAD patients provide independent evidence that BNP is a strong predictor of cardiovascular risk in patients with stable angina independent of left ventricular systolic performance and known risk factors.

Natriuretic peptides in heart valve disease

Synthesis and release of B-type natriuretic peptide (BNP) are increased in heart failure, and plasma concentrations provide important therapeutic and prognostic information. Recent studies have shown that BNP concentrations are also increased with disease of the mitral and aortic valves. The extent of the increase is broadly related to the severity of the valve abnormality and the degree of consequent cardiac remodelling. BNP concentrations appear to relate to prognosis in these patients and might have a role in identifying suitable candidates for cardiac surgery. This paper reviews the current literature and identifies areas where further research is required if assessment of BNP is to be of practical use.

Plasma homocysteine concentration and its relation to symptoms of vascular disease in psychogeriatric patients

BACKGROUND

There is a high frequency of elevated plasma total homocysteine (tHcy) concentrations in elderly patients with mental disorders. Psychogeriatric patients with a history of vascular disease exhibit a significantly higher plasma tHcy concentration than patients without vascular disease.

METHOD

The main reason for the present study is to further investigate the association between plasma tHcy concentration and vascular disease in psychogeriatric patients. We therefore investigated 152 psychogeriatric patients and determined plasma tHcy and its most important determinants (serum folate and serum cobalamin, serum cystatin C and serum creatinine). The patients were divided into two groups according to the presence of vascular disease. Eighty-seven patients had concomitant vascular disease. We also analysed the natriuretic peptide N-terminal pro brain natriuretic peptide (NT-proBNP) and protein S-100B in serum. NT-proBNP is a marker for congestive heart failure, whereas protein S-100B is a marker for brain damage.

RESULTS

The plasma tHcy concentration is elevated in the presence of dementia or vascular disease in psychogeriatric patients. The presence of dementia or vascular disease is also associated with higher age, renal impairment and lower serum folate concentration than in patients without dementia or vascular disease. Furthermore, we observed elevated serum concentrations of NT-proBNP in patients with dementia or vascular disease as a sign of poorer cardiovascular status. Likewise, protein S-100B concentrations were elevated in patients with dementia or vascular disease, possibly indicating brain damage in these groups of patients.

CONCLUSION

The high frequency of comorbidity of vascular disease and mental illness indicates a possibility to prevent and treat psychogeriatric disease by actively counteracting vascular disease in patients with psychogeriatric symptoms. Routine determination of NT-proBNP is valuable for obtaining information about cardiovascular status.

The role of NT-proBNP in the diagnostics of isolated diastolic dysfunction: correlation with echocardiographic and invasive measurements

AIMS

Diastolic heart failure is a frequent entity but difficult to diagnose. N-terminal pro-B type natriuretic peptide (NT-proBNP) was therefore investigated as a possible non-invasive parameter to diagnose isolated diastolic dysfunction.

METHODS AND RESULTS

Sixty-eight symptomatic patients with isolated diastolic dysfunction and preserved left ventricular ejection fraction (LVEF) (> or =50%) and 50 patients with regular left ventricular (LV) function were examined by conventional echocardiography, tissue Doppler imaging (TDI), and left and right heart catheterization. Plasma NT-proBNP levels were determined simultaneously. Median NT-proBNP plasma levels were elevated [189.54 pg/mL (86.16-308.27) vs. 51.89 pg/mL (29.94-69.71); P<0.001] and increased with greater severity of the diastolic dysfunction (R=0.67, P<0.001). According to the recevier operating characteristic analysis, LV end-diastolic pressure [area under the curve (AUC) 0.84] was the most specific parameter, which had a low sensitivity (61%), however. The reliability of NT-proBNP was similar to TDI indices (AUC 0.83 vs. 0.81) and improved when compared with conventional echocardiography (AUC 0.59-0.70). NT-proBNP levels had the best negative predictive value of all methods (94%) and correlated strongly with indices of LV filling pressure, as determined by invasive measurements. Multivariable linear regression analysis confirmed NT-proBNP as an independent predictor of diastolic dysfunction with an Odds ratio of 1.2 (1.1-1.4, CI 95%) for every unit increase of NT-proBNP.

CONCLUSION

NT-proBNP can reliably detect the presence of isolated diastolic dysfunction in symptomatic patients and is an useful tool to rule out patients with reduced exercise tolerance of non-cardiac origin.

Preoperative plasma N-terminal pro-brain natriuretic peptide as a marker of cardiac risk in patients undergoing elective non-cardiac surgery

Background

Plasma N-terminal pro-brain natriuretic peptide (NTproBNP) is a sensitive marker for heart failure. This study tested whether the preoperative plasma level of NTproBNP could predict cardiac complications in patients undergoing non-cardiac surgery.

Methods

A total of 190 consecutive patients who underwent elective non-cardiac surgery that required general anaesthesia were studied. In addition to routine preoperative evaluation, a blood sample was taken for estimation of plasma NTproBNP concentration. Postoperative cardiac complications were defined as cardiac death, acute coronary syndrome, heart failure and haemodynamic compromise from cardiac arrhythmias.

Results

Fifteen of the 190 patients had a cardiac complication: four had acute coronary syndrome and 13 had congestive heart failure. NTproBNP concentration was significantly higher in patients with a cardiac complication; a level greater than 450 ng/l was predictive of cardiac complications with a sensitivity of 100 per cent and a specificity of 82·9 per cent. Other factors associated with cardiac complications were a higher American Society of Anesthesiologists grade, age and clinical cardiac impairment, but in a multivariate analysis NTproBNP level was the only independent factor.

Conclusion

Preoperative plasma NTproBNP concentration may be an independent predictor of cardiac complications in patients undergoing non-cardiac surgery.

Complementary roles of simple variables, NYHA and N-BNP, in indicating aerobic capacity and severity of heart failure

AIMS

The extent of exercise intolerance in patients with chronic heart failure (CHF) is dependent on and representative of the severity of heart failure. However, few primary care physicians have direct access to facilities for formal exercise testing. We have therefore explored whether information readily obtainable in the community can reliably predict the functional capacity of patients.

METHODS AND RESULTS

Ninety-six subjects with a wide range of cardiac function (10 healthy controls and 86 CHF patients with NYHA classes I-IV, LVEF 36.9+/-15.2%) were recruited into the study and had resting plasma N-BNP and cardiopulmonary exercise testing to measure peak oxygen consumption (VO2). Significantly higher N-BNP levels were found in the CHF group (299.3 [704.8] fmol/ml, median [IQR]) compared with the healthy control group (7.2 [51.2] fmol/ml), p<0.0001. There were significant correlations between peak VO2 and N-BNP levels (R=0.64, P<0.001), peak VO2 and NYHA class (R=0.76, P=0.001), but no significant correlation was seen between peak VO2 and LVEF (R=0.0788, P=0.33). Multivariate analysis identified plasma N-BNP (P<0.0001) and NYHA class (P<0.0001) as significant independent predictors of peak VO2. Logistic modelling with NYHA class and log N-BNP to predict peak VO2<20 ml/kg/min showed that the area under the curve of receiver-operating-characteristic (ROC) curve was 0.906 (95% CI 0.844-0.968). A nomogram based on the data has been constructed to allow clinicians to estimate the likelihood of peak VO2 to be <20 ml/kg/min for given values of plasma N-BNP and NYHA class.

CONCLUSIONS

By combining information from a simple objective blood test (N-BNP) and a simple scoring of functional status (NYHA), a clinician can deduce the aerobic exercise capacity and indirectly the extent of cardiac dysfunction of patients with CHF.

Serum N-Terminal pro-BNP Levels Correlate with Symptoms and Echocardiographic Findings in Patients with Mitral Stenosis

This study is designed to evaluate the N-terminal pro-BNP (NTproBNP) levels in patients with mitral stenosis (MS) and its possible correlation with clinical and echocardiographic parameters of the disease. The study group consisted of 29 patients with isolated MS (patients with greater mild regurgitation were excluded) and 20 normal control subjects of similar age and gender distribution. Blood samples for NTproBNP were collected at the time of clinical and echocardiographic examination. NTproBNP levels were elevated in patients with MS compared to controls (325 +/- 249 pg/dL [19.9-890] versus 43 +/- 36 pg/dL [5.76-193.3], P < 0.001). Patients with atrial fibrillation had significantly higher NTproBNP levels compared to those with sinus rhythm (561 +/- 281 pg/dL versus 254 +/- 194 pg/dL, P = 0.044). MS patients with sinus rhythm also had higher NTproBNP levels compared to controls (254 +/- 194 pg/dL versus 43 +/- 36 pg/dL, P = 0.00011). NT pro BNP levels correlated to the LA (R = 0.73, P < 0.0001) and RV (R = 0.41, P = 0.042) diameters, mitral valve area (R =-0.45, P = 0.025), mean mitral gradient (R = 0.57, P = 0.003), peak PAP (R = 0.7, P = 0.03), and NYHA functional class (R = 0.61, P = 0.007). In conclusion, serum NTproBNP levels correlate well with echocardiographic findings and functional class in patients with MS and can be used as a marker of disease severity. Additionally, it may have a potential use as an additional noninvasive and relatively cheap method in monitoring disease progression especially in patients with poor echocardiographic windows.

Plasma N-terminal pro-brain natriuretic peptide and brain natriuretic peptide in assessment of acute dyspnea

We examined the analytical correlation between non-radioimmunometric plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and B-type natriuretic peptide (BNP) and evaluated whether NT-proBNP or BNP was superior in the emergency diagnosis of heart failure and whether this was influenced by age, gender, body mass index (BMI) and renal function. Data were collected prospectively from patients admitted to the emergency department for acute dyspnea. Plasma BNP (Triage, Biosite) and NT-proBNP (Elecsys, Roche diagnostic(R)) were measured at admission in addition to other standard biological parameters and clinical variables. Reference diagnosis was adjudicated by two independent cardiologists using the European society of cardiology guidelines. We evaluated the influence of creatinine clearance, age, gender and BMI on plasma BNP and NT-proBNP levels. One hundred and sixty consecutive patients were included: 84 females and 76 males, mean age 80.1 + 13.5 (16-98). The analytical correlation between the automated electro-chemiluminescence immunoassay for NT-proBNP and the single use fluorescence immunoassay for BNP was satisfactory using the equation: NT-proBNP = 1.1 BNP + 0.57 and a correlation r = 0.93. This was established over a wide range of concentration (5-6400 pg/ml for BNP). Areas under receiver operating characteristic (ROC) curve for BNP and NT-proBNP as a diagnostic marker for heart failure were 0.82 and 0.84, respectively and a BNP level of 150 pg/ml has similar sensitivity and specificity that NT-proBNP level of 1000 pg/ml. The correlation was not influenced by age, gender and BMI of patients. Renal dysfunction did not affect significantly this correlation (r = 0.93). We conclude that NT-proBNP, as assayed in the present study, correlates closely with BNP. This correlation is only slightly modulated by creatinine clearance values. The NT-proBNP appears as accurate as BNP according to area under ROC curve. Used in conjunction with other clinical information, rapid measurement of BNP or NT-proBNP is useful in establishing or excluding the diagnosis of congestive heart failure in patients with acute dyspnea.

Plasma B-type Natriuretic Peptide Levels and Risk Factors for Congestive Heart Failure in a Japanese General Population

This cross-sectional study was performed to establish the rationale for BNP testing for identifying subjects at high risk of congestive heart failure (CHF) in a screening setting. Plasma BNP concentrations were measured in 8,178 community-dwelling residents (mean age, 62 +/- 12 years; 3,194 males). First, in order to determine age- and sex-related reference values for plasma BNP levels, subjects having factors known to influence plasma BNP levels were excluded. The remaining 3,410 subjects were eligible for the reference study. Second, to verify BNP testing for screening for subjects at high risk of CHF, the clinical characteristics of subjects showing abnormally high plasma BNP levels (> or = 97.5 percentile for each age- and sex-specific value of the reference cohort) were examined. In the reference subjects, plasma BNP levels increased with age in both genders, and were higher in women than in men. In the original cohort, age- and sex-specific reference values for high plasma BNP levels were related to the presence of major ECG abnormalities, hypertension, mildly elevated serum creatinine levels, and a history of coronary heart disease. The results of the present study indicate that individuals with high plasma BNP levels in the community have accumulating risk factors for CHF. This suggests that plasma BNP measurement may be a useful screening test for identification of individuals at high risk of CHF within a Japanese general population.

Biochemical indicators of cardiac and renal function in a healthy elderly population

OBJECTIVES

To examine the distributions of NT-proBNP and cystatin C and their relation to age, gender, and other physiological factors in an apparently healthy elderly population.

METHOD

NT-proBNP and cystatin C were analyzed in 407 and 408 healthy individuals, median age: 65 (range 40-76).

RESULTS

Increasing age, female gender and CRP were independently associated to higher NT-proBNP levels. Age, body mass index, and CRP level were independently associated to the cystatin C level. In women and men, < or =65 years, the 97.5th percentile value for NT-proBNP was 268 ng/l and 184 ng/l, in those older, 391 ng/l and 269 ng/l. For those < or =65 years the 97.5th percentile value for cystatin C was 1.12 mg/l, and for those older 1.21 mg/l.

CONCLUSION

In a healthy elderly population, NT-proBNP is influenced by age and gender, whereas cystatin C is influenced by age but not by gender. Both markers seem to be associated to the CRP level.

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.

Multicenter evaluation of the Roche NT-proBNP assay and comparison to the Biosite Triage BNP assay

BACKGROUND

Brain natriuretic peptides (BNPs) are useful in the assessment of heart failure, left ventricular dysfunction, and acute coronary syndromes.

METHODS

We performed a multicenter evaluation of the automated Roche NT-proBNP assay and compared its performance to the Biosite Triage BNP assay.

RESULTS

The N-terminal (1-76) pro brain natriuretic peptide (NT-proBNP) method is precise (CV<or=6.1%), has a wide dynamic measuring range (30-35000 ng/l), is free from common interferences, and does not cross-react with BNP. EDTA or heparinized plasma samples collected in glass or plastic tubes can be used, and samples are stable at room temperature or 4 degrees C for up to 3 days. In contrast, the Biosite BNP assay has >2-fold higher CV, and plasma samples are more labile when stored at room temperature and 4 degrees C. Comparison studies showed a reasonable correlation between NT-proBNP and BNP assays, with a substantially higher slope bias of 6-20 for the NT-proBNP assay.

CONCLUSIONS

The automated Roche NT-proBNP assay has good analytical performance and better precision than the Biosite BNP assay. Unlike BNP, NT-proBNP is stable in EDTA plasma for 3 days at room temperature or longer at 4 degrees C. The Roche NT-proBNP is fully automated and will accommodate the testing of large numbers of clinical samples for assessing cardiac dysfunction.

The role and assessment of ventricular peptides in heart failure

Although heart failure may be diagnosed readily in its advanced stages, it may be difficult to diagnose clinically in its early stages.Thus, there is a critical need for an inexpensive, simple, rapid,and objective test for heart failure. This article discusses the role and assessment of ventricular natriuretic peptides and related pep-tides in heart failure.

N-terminal pro-brain natriuretic peptide for discriminating between cardiac and non-cardiac dyspnoea

AIM

Evaluation of N-terminal pro-brain natriuretic peptide (NT-proBNP) to confirm or disprove heart failure in community patients complaining of dyspnoea.

METHODS AND RESULTS

General practitioners referred 345 consecutive patients complaining of dyspnoea to our hospital-based clinic, where a diagnosis was established based on a combined programme for heart and lung diseases including echocardiography. The level of NT-proBNP in plasma was also measured. The mean (S.D.) concentration of NT-proBNP in patients with heart failure was significantly higher, 189 (270) pmol/l in patients with heart failure (n=81), than in patients with non-cardiac dyspnoea (n=264), 17 (38) pmol/l (P<0.001). In patients > or = 50 years NT-proBNP <11 pmol/l for men and <17 pmol/l for women excluded heart failure with a negative predictive value of 97% while the positive predictive value was 53%, the sensitivity 95% and the specificity 68%. Areas under receiver operator characteristic curves for men and women were 0.93 and 0.90, respectively.

CONCLUSION

In a relevant setting of primary care patients complaining of dyspnoea, NT-proBNP seems promising for disproval of heart failure, and this test may reduce the need for echocardiographic screening with 50%. However, the discrimination levels of NT-proBNP found in this study may need prospective confirmation, before the test can be generally recommended.

Concentrations of N-terminal pro-brain natriuretic peptide and troponin T in plasma of 75-year-old apparently healthy persons

Clinical chemical reference values for older persons are sparse and mostly intermixed with those for younger persons. We had a unique opportunity to obtain blood samples from volunteers who were 75years old and living in two districts of Vienna, Austria. Consequently, we utilized stored plasma samples to obtain reference intervals for 120 apparently healthy 75-year-old participants for pro-brain natriuretic peptide (proBNP), as well as for troponin T. The N-terminal (NT)-proBNP protein assay is currently used as a diagnostic and prognostic aid in patients with heart failure and as a prognostic marker in acute coronary syndromes. Specifically, the concentration of NT-proBNP in serum or plasma aids in the prognosis of ventricular systolic dysfunction and helps to differentiate between cardiac and non-cardiac causes. The median NT-proBNP plasma value for men and women in our cohort was calculated as 98pg/ml, comparing favorably with reported values, in that a NT-proBNP concentration less than 100pg/ml excludes acutely decompensated heart failure. Our calculated 97.5 percentile was slightly higher (359 pg/ml) than the 97.5 percentile in a group of 50–65-year-old persons (198 and 222pg/ml for men and women, respectively) revealing the influence of age on this parameter. Because of its high tissue-specificity, cardiac troponin T is a cardiospecific, highly sensitive marker for myocardial damage. However, the troponin T concentrations in the plasma specimens from this cohort were all below the detection limit of 0.01ng/ml, preventing any further data handling.

Identification of previously undiagnosed left ventricular systolic dysfunction: community screening using natriuretic peptides and electrocardiography

AIMS

We examined strategies to improve the positive predictive value of natriuretic peptides in screening for undiagnosed left ventricular systolic dysfunction (LVSD) in the community.

METHODS AND RESULTS

The value of B-type(BNP), N-terminal proB-type (N-BNP) and N-terminal proAtrial(N-ANP) natriuretic peptides was prospectively assessed in 1360 subjects (45-80 years) together with echocardiography and electrocardiography. Seventeen individuals had definite and 13 had borderline, LVSD. Receiver-operating-characteristic (ROC) curve analysis showed the superiority of BNP (ROC areas 0.942 for definite LVSD, P<0.03; 0.934 for borderline LVSD, P<0.003) compared to N-BNP or N-ANP. Peptide levels, major ECG abnormality and ischaemic heart disease (IHD) history were independent predictors of LVSD. Logistic regression modelling incorporating these factors improved ROC areas for all natriuretic peptides. The specificity of all natriuretic peptides is enhanced by consideration of these factors.

CONCLUSIONS

In population screening for definite LVSD, consideration of plasma natriuretic peptide levels together with the presence of major ECG abnormalities and IHD history reduces by a factor of six (in comparison to consideration of plasma natriuretic peptide levels in isolation) the number of subjects requiring echocardiography to detect one case of LVSD (for BNP, 44 falling to seven). Similar improvements were evident for N-ANP and N-BNP. Inclusion of major ECG abnormalities and IHD history improves the performance of any natriuretic peptide used in screening programmes for ruling in undiagnosed LVSD.

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.

Management of Acute Decompensated Heart Failure in the Emergency Department

Heart failure, a disease of epidemic proportions, has a tremendous clinical and financial impact on the US health care system. With more than 5 million Americans diagnosed with heart failure and 5-year mortality approaching 50%, it is the most common cause of hospitalization in patients older than 65 years and is the single most expensive diagnosis in the US health care system. Because the average US hospital loses more than 1000 dollars per heart failure admission, effective therapies that decrease length of stay, reduce hospital costs, and prevent 30-day readmissions are needed. This article reviews the relevant pathophysiology of heart failure, discusses the newest diagnostic strategies for emergency department diagnoses, evaluates recent advances and effects of early aggressive therapies, and presents a suggested algorithm for the treatment of acutely decompensated heart failure in emergency departments.

N-terminal pro B type natriuretic peptide, but not the new putative cardiac hormone relaxin, predicts prognosis in patients with chronic heart failure

OBJECTIVE

To determine whether the plasma concentration of the putative new cardiac hormone relaxin is predictive of clinical outcome in patients with chronic heart failure (CHF).

DESIGN

Plasma relaxin and N-terminal pro B type natriuretic peptide (NT pro BNP) concentrations were measured in 87 patients admitted in an emergency with CHF caused by left ventricular systolic dysfunction. These were related to death and death or readmission with CHF over the following year.

SETTING

Western Infirmary, Glasgow, UK.

MAIN OUTCOME MEASURES

Plasma concentrations of relaxin and NT pro BNP; time to death or hospitalisation caused by heart failure.

RESULTS

Plasma concentrations of both relaxin and NT pro BNP were greatly increased. Of the 43 patients with NT pro BNP above the group median concentration, 23 (53%) died and 30 (70%) died or were hospitalised with CHF. Among the 44 with concentrations below the median, these numbers were 5 (11%) and 12 (27%), respectively (p < 0.0001 and p < 0.0001, respectively). Plasma NT pro BNP concentration remained an independent predictor of an adverse clinical outcome in a multivariate analysis. Of the 42 patients with a relaxin concentration above the median, 13 (31%) died and 20 (48%) died or were hospitalised. Below the median, these numbers were 15 of 45 (33%) and 22 of 45 (49%) (p = 0.76 and p = 0.84, respectively).

CONCLUSIONS

NT pro BNP is a powerful and independent predictor of outcome in CHF, whereas relaxin, also secreted by the heart in increased amounts in CHF, is not.

Plasma N-terminal pro-brain natriuretic peptide in Type 1 diabetic patients with and without diabetic nephropathy

AIMS

Plasma N-terminal pro-brain natriuretic peptide (NT proBNP) is produced and released from cardiac ventricles; it is elevated in patients with heart failure, hypertension and chronic renal failure. This study aimed to examine the plasma levels of NT proBNP and their relationship in Type 1 diabetic patients with and without diabetic nephropathy.

METHODS

We developed a non-competitive immunoluminometric assay with in-house antibodies to the N- and C-terminal domains of NT proBNP. We compared NT proBNP levels between 47 normoalbuminuric patients (group 1), 12 microalbuminuric patients (group 2) and 12 patients with macroalbuminuria (group 3).

RESULTS

There were significant differences in 24-h systolic and diastolic blood pressure, diabetes duration, serum creatinine, LDL-cholesterol and HbA1c between the three groups; other parameters did not differ significantly. NT proBNP (median and range) levels were 5 (0.75-68), 22 (0.75-82) and 23 (0.75-374) fmol/ml for groups 1-3, respectively. Log-transformed data of NT proBNP were used to compare all three groups (P=0.016). The Pearson correlation between NT proBNP and albuminuria (R=0.27; P=0.02) was positive; HbA1c (R=0.25; P=0.03) and age (R=0.33; P=0.005) correlated significantly as well. On the basis of multiple regression analysis, the adjusted difference remained significant between the three groups.

CONCLUSIONS

This is the first demonstration that NT proBNP levels are significantly higher in Type 1 diabetic patients with albuminuria. This may be caused by a down-regulation of A-type guanylate cyclase-coupled natriuretic peptide receptors in renal tubules or by elevated NT proBNP levels leading to higher glomerular hydraulic pressure or higher capillary permeability and possibly increased albumin excretion. Further studies are required to investigate the potential role of NT proBNP in patients with diabetic nephropathy and such other co-morbidities as cardiovascular disease.

Cardiac hormones as diagnostic tools in heart failure

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

Diagnostic and prognostic usefulness of natriuretic peptides in emergency department patients with dyspnea

More than 4.5 million Americans have congestive heart failure (CHF), close to 550,000 new cases are diagnosed each year, and one third of known patients with CHF are annually admitted to the hospital. Emergency department diagnosis of CHF is often based on history and physical examination findings along with results of ancillary tests, such as chest radiography and ECG. Although signs and symptoms of fluid overload, such as lower extremity edema and dyspnea, raise the suspicion of CHF, their lack of sensitivity makes them poor screening tools. The natriuretic peptides are promising markers of myocardial dysfunction and heart failure. Because of their relationship to myocardial pressure and stretching, natriuretic peptides have been investigated over the past 5 decades as both diagnostic and prognostic markers in acute coronary syndromes and CHF. This article discusses each of the natriuretic peptides and attempts to delineate their potential diagnostic and prognostic roles in the ED.

Low pro-brain natriuretic peptide levels predict benign clinical outcome in acute pulmonary embolism

BACKGROUND

The role of pro-brain natriuretic peptide (proBNP) for the prediction of clinical outcome has not been examined in patients with acute pulmonary embolism (PE).

METHODS AND RESULTS

ProBNP levels were measured in 73 patients with acute PE within 4 hours of admission. Adverse clinical outcome was defined as in-hospital death or the need for at least 1 of the following: cardiopulmonary resuscitation, mechanical ventilation, pressors, thrombolysis, catheter fragmentation, or surgical embolectomy. In the 53 patients with a benign clinical outcome, proBNP (median 121, range 16 to 34 802 pg/mL) was lower than in 20 patients with adverse clinical outcome (median 4250, range 92 to 49 607 pg/mL; P<0.0001). The negative predictive value of proBNP levels <500 pg/mL to predict adverse clinical outcome was 97% (95% confidence interval 84 to 99). ProBNP remained an independent predictor for adverse clinical outcome (odds ratio 14.6; 95% confidence interval 1.5 to 139.0; P=0.02) after adjusting for severity of PE (submassive/massive), troponin T levels >0.01 ng/mL, age >70 years, gender, and history of congestive heart failure.

CONCLUSIONS

Low proBNP levels predict an uneventful hospital course in patients with acute PE. A proBNP level <500 pg/mL identifies patients who will be potential candidates for an abbreviated hospital length of stay or care on a completely outpatient basis.

[Value of NTproBNP concentration in an out-of-hospital adult population]

INTRODUCTION

The diagnosis of chronic heart failure (CHF) is based on demonstrating the cardiac origin of clinical manifestations. Echocardiography is the method of choice for the detection of left ventricular systolic dysfunction (LVSD). Brain natriuretic peptide (BNP) rises during LVSD.

OBJECTIVES

To analyze the plasma concentration of N-terminal brain natriuretic propeptide (NTproBNP) in a general adult population in relation to different spontaneous circumstances and to study its capacity for identifying patients with LVSD.Methods. A cardiological examination was made and plasma NTproBNP levels were measured in a randomized group of 203 people (49-81 years old) from the Community of Valencia.

RESULTS

The average NTproBNP concentration was 52.2 98.2 pmol/l. NTproBNP levels varied with age, gender and functional stage (NYHA). The highest NTproBNP values were observed in people who had previously suffered from acute pulmonary edema or who had an ejection fraction (EF) of less than 40%. There was also a significant elevation in patients with nocturnal dyspnea, orthopnea, atrial fibrillation, EF < or = 50%, angina, and ankle edema. The best concentration of NTproBNP for differentiating EF < or = 50% was 37.7 pmol/l, with 92% sensitivity and 68% specificity.

CONCLUSIONS

The elevation of NTproBNP concentration indicates the cardiac origin of clinical manifestations and serves to select patients for echocardiographic examination. Low NTproBNP concentrations help to rule out LVSD.

NT-proBNP: a new diagnostic screening tool to differentiate between patients with normal and reduced left ventricular systolic function

OBJECTIVE

To evaluate whether measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP) can be used to differentiate patients with normal and reduced left ventricular ejection fraction (LVEF) in an unselected consecutive group of hospital inpatients.

SETTING

City general hospital, Copenhagen, Denmark.

PATIENTS AND DESIGN

During a 10 month period 2230 admissions to a city general hospital (80% of targeted patients) had an echocardiographic evaluation of left ventricular function, a comprehensive clinical evaluation, and blood analysis of N-terminal-pro-brain natriuretic peptide (NT-proBNP) within 24 hours of admission. Exclusions resulted from lack of informed consent or failure to obtain the required evaluations before death or discharge from hospital. Echocardiography was unsatisfactory in 37 patients, so the final number studied was 2193.

RESULTS

A raised NT-proBNP (>or= 357 pmol/l) identified patients with an LVEF of <or= 40% (n = 157) with a sensitivity of 73% and a specificity of 82%. The negative predictive value of having an NT-proBNP concentration below 357 pmol/l was 98%. Concentrations of NT-proBNP increased with increasing age and with decreasing LVEF (p < 0.05). A predicted concentration of NT-proBNP (corrected for age, sex, and serum creatinine) was determined for each patient. In patients with an NT-proBNP value less than predicted, the probability of having an LVEF of > 40% was more than 97%. This probability rapidly decreased to 70% as the measured NT-proBNP increased to 150% of the predicted value.

CONCLUSIONS

A single measurement of NT-proBNP at the time of hospital admission provides important information about LVEF in unselected patients.

Retrospective analysis of the cost-effectiveness of using plasma brain natriuretic peptide in screening for left ventricular systolic dysfunction in the general population

OBJECTIVES

We sought to assess the cost-effectiveness of using plasma brain natriuretic peptide (BNP) as a pre-echocardiographic screening test for left ventricular systolic dysfunction (LVSD) in the general population.

BACKGROUND

We hypothesized that plasma BNP and simple clinical parameters would reduce the number of echocardiograms needed and cost when screening for LVSD in the general population.

METHODS

A random sample of 1,257 community subjects (age 25 to 74 years) was examined. Three risk groups were formed: one group with symptomatic ischemic heart disease (IHD); a second group with blood pressure >160/95 mm Hg and/or an abnormal electrocardiogram (high risk); and a group with none of these risk factors (low risk). The BNP assay was adjusted to give a high sensitivity.

RESULTS

Left ventricular systolic dysfunction was prevalent in 0.7% (6/823), 6% (16/269), and 19% (26/140) of low-risk and high-risk subjects and IHD subjects, respectively. Raised BNP concentrations (>8 pg/ml) occurred in 41%, 64%, and 71%. Sensitivities of BNP for detecting LVSD were 83% (5/6), 94% (15/16), and 92% (24/26); and the negative predictive values were 99.8%, 99.0%, and 95.1%. Brain natriuretic peptide was not associated with LVSD in low-risk subjects (p = 0.087), but in IHD subjects (p = 0.015) and high-risk subjects (p = 0.023). Screening high-risk subjects by BNP before echocardiography could have reduced the cost per detected case of LVSD by 26% for the cost ratio of 1/20 (BNP/echocardiogram).

CONCLUSIONS

Subjects at low and high risk of LVSD can be identified by simple clinical parameters, and BNP testing further reduces the number of echocardiograms needed and the costs of screening in subjects at risk <75 years of age in the general population.

Radioimmunometric assay of natriuretic peptide type-B (BNP) in heart failure

The aim of this study was to assess the value of the radioimmunometric determination of natriuretic peptide type-B (brain natriuretic peptide, BNP) in the diagnosis and prognosis of heart failure, and to study the association between BNP and the clinical, analytical and echocardiographic variables associated with the evolution of heart failure. The study group included 169 patients (74 women and 95 men; mean, 66 years) with heart failure of different causes, admitted consecutively to our hospital. BNP levels were measured with a radioimmunometric assay (Shionora BNP Cis ) after day 3 of admission. Patients were also studied by echocardiography. A significant association between the cause of heart failure and the BNP concentration was found (patients with ischaemic disease had the highest BNP values). Systolic function was worse in patients with ischaemic disease or dilated cardiomyopathy. High BNP values were also associated with advanced functional class and male sex. Plasma creatinine correlated positively with plasma BNP. However, we found no significant association with the other clinical variables evaluated. Of the echocardiographic variables analysed, BNP correlated positively with the ventricular diameter and pulmonary artery systolic pressure, and inversely with the shortening fraction; patients with severely impaired systolic function had the highest BNP values. It can be concluded that BNP levels (by radioimmunometric assay) are increased in patients with heart failure, and increase in relation to left ventricular dysfunction and the severity of heart failure. The strong independent association of plasma BNP with the left ventricular ejection fraction, its stability and the low cost of measurement suggest that plasma BNP assay could become a routine test. BNP assay could be included as an important factor in clinical and therapeutic decision making, as it complements the information provided by other variables used in the diagnosis of heart failure.

NT-proBNP y desplazamiento del plano auriculoventricular. Relación e implicaciones diagnósticas

INTRODUCTION AND OBJECTIVES

NT-proBNP is useful in the diagnosis of heart failure and ventricular dysfunction. Left atrioventricular plane displacement (AVPD) is a consolidated index of ventricular function. Our objective was to carry out a multicenter population-based study to establish the relationship between plasma NT-proBNP levels with AVPD values.

PATIENTS AND METHOD

We studied 215 subjects (age 66 9 years; 57.7% women) chosen from a random sample of 432 people from the Community of Valencia, who previously reported suffering from some degree of dyspnea. Doppler echocardiography was done, AVPD was calculated and plasma NT-proBNP concentrations were determined. All studies were completed in 194 patients.

RESULTS

For the whole population NT-proBNP was 88 (0-2,586) pg/ml and AVPD was 11.9 1.6 mm. NT-proBNP concentration correlated well with AVPD (r = 0.44; p < 0.00001), and higher peptide levels were obtained in AVPD quartiles that indicated less displacement (p < 0.05). When NT-proBNP values were grouped according to their association with AVPD lower or higher than the 50th percentile AVPD, the difference was significant at p < 0.01. When AVPD values lower and higher than 10 mm were compared, NT-proBNP values were higher in persons with AVPD lower than 10 mm (p < 0.05).

CONCLUSIONS

This population study found higher NT-proBNP concentrations in subjects with lower AVPD, and illustrates the potential diagnostic usefulness of NT-proBNP in clinical practice.

Plasma concentrations of N-terminal pro-brain natriuretic peptide in control children from the neonatal to adolescent period and in children with congestive heart failure

OBJECTIVE

To determine plasma levels of N-terminal pro-brain natriuretic peptide (N-BNP) in control children to establish a normal age-dependent range from the neonatal period to adulthood. In addition, plasma concentrations of N-BNP were measured in children with congestive heart failure (CHF) and correlated with ejection fraction and clinical symptoms of heart failure.

METHODS

For establishing a normal age-dependent range of plasma N-BNP, venous blood samples were taken in 133 control patients from the neonatal period to adulthood (10 days-32 years) and in 31 children with CHF. Plasma N-BNP levels were determined by an enzyme immunoassay. In children (1 month-14 years) with CHF, plasma N-BNP levels were correlated to ejection fraction measured by echocardiography and clinical symptoms of heart failure using the Ross Score.

RESULTS

N-BNP levels in control children, adolescents, and adults did not show a significant age-related difference. In control children, the normal range was established between 150 (10th percentile) and 430 fmol/mL (90th percentile). Mean plasma N-BNP in control children was 311 fmol/mL (range: 74-654 fmol/mL). In 31 children with CHF, the plasma N-BNP levels were significantly higher (mean: 846; range: 219-2718) than in control children. N-BNP levels showed a negative correlation with the ejection fraction (r = -0.53) and a positive correlation with the clinical heart failure score (r = 0.74).

CONCLUSIONS

Plasma N-BNP levels reflect the severity of symptoms of heart failure and the impairment of cardiac function in children with CHF. In the future, determination of plasma N-BNP levels may be used as a helpful adjunct to monitor the effect of various treatments for CHF in children.