Combination of B-type natriuretic peptide levels and non-invasive hemodynamic parameters in diagnosing congestive heart failure in the emergency department

This study aimed to assess whether the combination of a B-type natriuretic peptide (BNP) level with various noninvasive hemodynamic parameters can help physicians more quickly and accurately diagnose congestive heart failure and determine the type of left ventricular dysfunction present in patients presenting to the emergency department with dyspnea. Subjects were 98 men (aged 64.57+/-1.23 years) that presented to the VA San Diego Healthcare System. Hemodynamic parameters were measured using impedance cardiography, and BNP levels were quantified using a rapid immunoassay. All patients with a BNP <100 pg/mL (n=37) had no evidence of congestive heart failure 97% of the time. In those with a BNP >100 pg/mL (601+/-55 pg/mL; n=61), a cardiac index of 2.6 L/min/m2 is 65% sensitive and 88% specific in determining systolic dysfunction. In patients with a BNP >100 pg/mL, a multivariate model consisting of noninvasive hemodynamic measurements was able to predict cardiac deaths, readmissions, and emergency department visits within 90 days with 83% accuracy. The authors conclude that, in patients presenting to an emergency department with dyspnea, the addition of impedance cardiography measurements to BNP level measurements will more effectively diagnose congestive heart failure and determine both the type of heart dysfunction and the severity of illness.     

Gender-specific risk stratification with B-type natriuretic peptide levels in patients with acute dyspnea: insights from the B-type natriuretic peptide for acute shortness of breath evaluation study.

OBJECTIVES: We examined whether B-type natriuretic peptide (BNP) levels allow gender-specific risk stratification in patients with acute dyspnea. BACKGROUND: B-type natriuretic peptide levels determined in patients with heart failure correlate with the severity of disease and prognosis. Gender differences in risk prediction are poorly examined. METHODS: The BASEL (B-type natriuretic peptide for Acute Shortness of Breath Evaluation) Study enrolled 190 female and 262 male patients presenting with acute dyspnea. RESULTS: At 24 months, cumulative mortality was comparable in women and men (38% vs. 35%, p = 0.66). Cox regression analyses revealed that BNP levels >500 pg/ml indicated a 5.1-fold increase in mortality for women (95% confidence interval [CI] 3.0 to 8.5, p < 0.001) versus a 1.8-fold increase in men (95% CI 1.2 to 2.6; p = 0.007). The area under the receiver-operating characteristic curve (AUC) for BNP to predict death was significantly higher in female (AUC: 0.80, 95% CI 0.73 to 0.86) than in male patients (AUC: 0.64, 95% CI 0.57 to 0.71; p = 0.001 for the comparison of AUC(women) versus AUC(men)). Women with BNP >500 pg/ml displayed a higher mortality as compared with men with BNP >500 pg/ml (68% vs. 46%, p = 0.015). Interaction analysis showed that BNP is a stronger predictor of death in women than in men (p = 0.008). CONCLUSIONS: B-type natriuretic peptide plasma levels seem to be stronger predictors of death in women than in men.     

B-type natriuretic peptide predicts future cardiac events in patients presenting to the emergency department with dyspnea

STUDY OBJECTIVE: B-Type natriuretic peptide (BNP) is a neurohormone secreted from the cardiac ventricles in response to volume expansion and pressure overload. We have recently demonstrated that BNP can differentiate congestive heart failure (CHF) from other causes of dyspnea in patients presenting to the emergency department. In this study, we assess whether BNP levels drawn in patients presenting with dyspnea to the ED were a predictor of future cardiac events. METHODS: In 325 patients presenting with dyspnea to the ED, BNP levels were determined. Patients were then followed up for 6 months to determine the following end points: death (cardiac and noncardiac), hospital admissions (cardiac), and repeat ED visits for CHF. Receiver operating characteristic (ROC) curves, relative risks (RRs), and Kaplan-Meier plots were used to assess the ability of BNP levels to predict future cardiac events. RESULTS: The area under the ROC curve using BNP to detect a CHF end point-a CHF death, hospital admission, or repeat ED visit-was 0.870 (95% confidence interval [CI] 0.826 to 0.915). A BNP value of 480 pg/mL had a sensitivity of 68%, specificity of 88%, and an accuracy of 85% for predicting a subsequent CHF end point. The area under the ROC curve using BNP to detect death from CHF was 0.881 (95% CI 0.807 to 0.954) and for any cardiac death was 0.877 (95% CI 0.822 to 0.933). BNP was not associated with death from noncardiac causes. Using Kaplan-Meier plots for all CHF events, rising BNP levels were associated with a progressively worse prognosis. Patients with BNP levels more than 480 pg/mL had a 51% 6-month cumulative probability of a CHF event. Alternatively, patients with BNP levels less than 230 pg/mL had an excellent prognosis with only 2.5% incidence of CHF end points. The RR of 6-month CHF death in patients with BNP levels more than 230 pg/mL was 24.1. The RR of 6-month noncardiac death with BNP levels more than 230 pg/mL was 1.1. BNP levels were also predictive of CHF events in subsets of patients with positive CHF histories and ED diagnoses. CONCLUSION: In this study population, BNP levels measured in patients presenting with dyspnea to the ED are highly predictive of cardiac events over the next 6 months.     

Accuracy of the isovolumic relaxation time in the emergency diagnosis of new-onset congestive heart failure with preserved left ventricular systolic function in the setting of B-type natriuretic peptide levels in the mid-range

Despite the fact that B-type natriuretic peptide (BNP) is a useful diagnostic complement to clinical and radiographic data in the emergency diagnosis of acute congestive heart failure, levels of BNP in the mid-range (100-500 pg/ml) are acknowledged to be inconclusive for the diagnosis. We assessed the diagnostic value of the pulsed Doppler-derived isovolumic relaxation time (IVRT) by bedside Doppler echocardiography in the emergency diagnosis of new-onset congestive heart failure with preserved systolic function in 43 patients presenting with acute severe dyspnea and inconclusive BNP levels. A short IVRT <50 ms was a good predictor of acute congestive heart failure in this clinical setting, with a positive predictive value of 94%.     

Utility of NT-proBNP for diagnosing heart failure in a heterogeneous population of patients with dyspnea. Spanish multicenter study

INTRODUCTION AND OBJECTIVES: Recent studies have shown that brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are useful in the diagnosis of heart failure in patients presenting with dyspnea. However, the cutoff values used with these markers vary according to patient characteristics and dyspnea severity. The aim of this study was to investigate the diagnostic accuracy of using the plasma NT-proBNP level for identifying heart failure in a heterogeneous population of patients with dyspnea. METHODS: A multicentre study involving 247 consecutive patients with recent-onset dyspnea was carried out at 12 Spanish hospitals. Patients previously diagnosed with heart failure or any other condition known to cause dyspnea were excluded. RESULTS: Of the 247 patients, 161 (65%) had heart failure. The remaining 86 (35%) presented with dyspnea of non-cardiac origin. Plasma NT-proBNP levels were higher in patients with heart failure (5600 [7988] pg/mL vs 1182 [4406] pg/mL; P=.0001), and increased as functional status deteriorated (P=.036). The area under the receiver operating characteristic curve was 0.87 (0.02) (95% CI, 0.81-0.91) for the optimum cutoff value of 1335 pg/mL. The sensitivity of this cutoff value for diagnosing heart failure was 77% (95% CI, 70%-83%), the specificity was 92% (95% CI, 84%-97%), the positive predictive value was 94%, and the negative predictive value was 68%. CONCLUSIONS: The plasma NT-proBNP concentration provides an accurate means of diagnosing heart failure. However, the negative predictive value found in this study was somewhat lower than the values found in previous studies involving more homogeneous patient populations.     

Use of B-type natriuretic peptide in the risk stratification of acute exacerbations of COPD

BACKGROUND: In patients with COPD, prognosis might be determined at least in part by the extent of cardiac stress induced by hypoxia and pulmonary arterial hypertension. METHODS: B-type natriuretic peptide (BNP), a quantitative marker of cardiac stress, was determined in 208 consecutive patients presenting to the emergency department with an acute exacerbation of COPD (AECOPD). The accuracy of BNP to predict death at a 2-year follow-up was evaluated as the primary end point. The need for intensive care and in-hospital mortality were determined as secondary end points. RESULTS: BNP levels were significantly elevated during the acute exacerbation compared to recovery (65 pg/mL; interquartile range [IQR], 34 to 189 pg/mL; vs 45 pg/mL; IQR, 25 to 85 pg/mL; p < 0.001), particularly in those patients requiring ICU treatment (105 pg/mL; IQR, 66 to 553 pg/mL; vs 60 pg/mL; IQR, 31 to 169 pg/mL; p = 0.007). In multivariate Cox regression analysis, BNP accurately predicted the need for ICU care (hazard ratio, 1.13; 95% confidence interval [CI], 1.03 to 1.24 for an increase in BNP of 100 pg/mL; p = 0.008). In a receiver operating characteristic analysis to evaluate the potential of BNP levels to predict short-term and long-term mortality rates, areas under the curve were 0.55 (SD, 0.71; 95% CI, 0.41 to 0.68) and 0.56 (SD, 0.53; 95% CI, 0.45 to 0.66, respectively). CONCLUSIONS: In patients with AECOPD, BNP levels independently predict the need for intensive care. However, BNP levels failed to adequately predict short-term and long-term mortality rates in AECOPD patients.     

Impact of atrial fibrillation on the diagnostic performance of B-type natriuretic peptide concentration in dyspneic patients: an analysis from the breathing not properly multinational study

OBJECTIVES: This study was designed to assess the diagnostic performance of B-type natriuretic peptide (BNP) in the diagnosis of acute congestive heart failure (CHF) in patients with permanent/paroxysmal atrial fibrillation (AF) presenting with acute dyspnea. BACKGROUND: It is unknown to what extent AF affects the diagnostic performance of BNP in patients presenting with acute dyspnea. METHODS: We studied 1,431 patients drawn from a cohort of patients (n = 1,586) with acute dyspnea who had BNP levels measured on arrival. Patients were prospectively classified according to the presence or absence of permanent/paroxysmal AF. RESULTS: In total, 292 patients had permanent/paroxysmal AF. In patients without HF, permanent/paroxysmal AF was associated with significantly higher BNP levels (p = 0.001). Conversely, in patients with HF, BNP levels did not differ significantly between patients with and without AF (p = 0.533). A BNP cutoff value of 100 pg/ml had a specificity of 40% and 79% for the diagnosis of acute HF in patients with and without AF, respectively. The areas under the receiver-operating characteristic curves were 0.84 (95% confidence interval 0.78 to 0.89) and 0.91 (95% confidence interval 0.89 to 0.93) for patients with and without AF, respectively. CONCLUSIONS: In patients without, but not in those with HF, the presence of AF is associated with higher circulating BNP levels, suggesting that a higher diagnostic threshold should be used in patients with AF.     

Brain natriuretic peptide levels and cardiac functional capacity in patients with dyspnea and isolated diastolic dysfunction

Diastolic heart failure affects approximately 40%-50% of patients presenting with signs and symptoms of heart failure. The aim of this study was to investigate the relationship between brain natriuretic peptide (BNP) levels and functional capacity in patients admitted with dyspnea and diagnosed with isolated diastolic dysfunction. Fifty-four patients (mean age, 57.4 +/- 8.5 years) with class-2 dyspnea with isolated diastolic dysfunction were enrolled. Serum levels of BNP were measured, and peak oxygen consumption (peak VO(2)), anaerobic threshold (AT), and metabolic equivalent (MET) values were determined with a cardiopulmonary exercise test (CPET). There was a negative correlation between BNP levels and exercise duration (P < 0.05, r = -0.304), AT (P < 0.05, r = -0.380), and number of MET (P < 0.05, r = -0.322) determined by CPET. When patients were divided into 2 groups according to BNP levels; BNP < or = 50 pg/mL (n = 40) versus BNP > 50 pg/mL (n = 14) and analyzed, those with BNP levels > 50 pg/mL had lower peak VO(2) (P = 0.05) and anaerobic threshold (P = 0.01) compared with patients with BNP < or = 50 pg/mL. The results suggest that BNP levels provide an indication about the functional capacity determined by CPET in patients admitted with dyspnea and isolated diastolic dysfunction.     

Utility of a rapid B-natriuretic peptide assay in differentiating congestive heart failure from lung disease in patients presenting with dyspnea.

OBJECTIVES: Since B-type natriuretic peptide (BNP) is secreted by the left ventricle (LV) in response to volume elevated LV pressure, we sought to assess whether a rapid assay for BNP levels could differentiate cardiac from pulmonary causes of dyspnea. BACKGROUND: Differentiating congestive heart failure (CHF) from pulmonary causes of dyspnea is very important for patients presenting to the emergency department (ED) with acute dyspnea. METHODS: B-natriuretic peptide levels were obtained in 321 patients presenting to the ED with acute dyspnea. Physicians were blinded to BNP levels and asked to give their probability of the patient having CHF and their final diagnosis. Two independent cardiologists were blinded to BNP levels and asked to review the data and evaluate which patients presented with heart failure. Patients with right heart failure from cor pulmonale were classified as having CHF. RESULTS: Patients with CHF (n = 134) had BNP levels of 758.5 +/- 798 pg/ml, significantly higher than the group of patients with a final diagnosis of pulmonary disease (n = 85) whose BNP was 61 +/- 10 pg/ml. The area under the receiver operating curve, which plots sensitivity versus specificity for BNP levels in separating cardiac from pulmonary disease, was 0.96 (p < 0.001). A breakdown of patients with pulmonary disease revealed: chronic obstructive pulmonary disease (COPD): 54 +/- 71 pg/ml (n = 42); asthma: 27 +/- 40 pg/ml (n = 11); acute bronchitis: 44 +/- 112 pg/ml (n = 14); pneumonia: 55 +/- 76 pg/ml (n = 8); tuberculosis: 93 +/- 54 pg/ml (n = 2); lung cancer: 120 +/- 120 pg/ml (n = 4); and acute pulmonary embolism: 207 +/- 272 pg/ml (n = 3). In patients with a history of lung disease but whose current complaint of dyspnea was seen as due to CHF, BNP levels were 731 +/- 764 pg/ml (n = 54). The group with a history of CHF but with a current COPD diagnosis had a BNP of 47 +/- 23 pg/ml (n = 11). CONCLUSIONS: Rapid testing of BNP in the ED should help differentiate pulmonary from cardiac etiologies of dyspnea.     

Diagnostic and prognostic utility of brain natriuretic Peptide in subjects admitted to the ICU with hypoxic respiratory failure due to noncardiogenic and cardiogenic pulmonary edema

BACKGROUND: Brain natriuretic peptide (BNP) is useful in diagnosing congestive heart failure (CHF) in patients presenting in the emergency department with acute dyspnea. We prospectively tested the utility of BNP for discriminating ARDS vs cardiogenic pulmonary edema (CPE). METHODS: We enrolled ICU patients with acute hypoxemic respiratory failure and bilateral pulmonary infiltrates who were undergoing right-heart catheterization (RHC) to aid in diagnosis. Patients with acute coronary syndrome, end-stage renal disease, recent coronary artery bypass graft surgery, or preexisting left ventricular ejection fraction /= 1,200 pg/mL, BNP had a specificity of 92% for CPE. Higher levels of BNP were associated with a decreased odds for ARDS (odds ratio, 0.4 per log increase; p = 0.007) after adjustment for age, history of CHF, and right atrial pressure. BNP was associated with in-hospital mortality (p = 0.03) irrespective of the final diagnosis and independent of APACHE (acute physiology and chronic health evaluation) II score. CONCLUSION: In ICU patients with hypoxemic respiratory failure, BNP appears useful in excluding CPE and identifying patients with a high probability of ARDS, and was associated with mortality in patients with both ARDS and CPE. Larger studies are necessary to validate these findings.     

Comparative value of Doppler echocardiography and B-type natriuretic peptide assay in the etiologic diagnosis of acute dyspnea

OBJECTIVES: We compared the accuracy of B-type natriuretic peptide (BNP) assay with Doppler echocardiography for the diagnosis of decompensated congestive left-heart failure (CHF) in patients with acute dyspnea. BACKGROUND: Both BNP and Doppler echocardiography have been described as relevant diagnostic tests for heart failure. METHODS: One hundred sixty-three consecutive patients with severe dyspnea underwent BNP assay and Doppler echocardiogram on admission. The accuracy of the two methods for etiologic diagnosis was compared on the basis of the final diagnoses established by physicians who were blinded to the BNP and Doppler findings. RESULTS: The final etiologic diagnosis was CHF in 115 patients. Twenty-four patients (15%) were misdiagnosed at admission. The BNP concentration was 1,022 +/- 742 pg/ml in the CHF subgroup and 187 +/- 158 pg/ml in the other patients (p < 0.01). A BNP cutoff of 300 pg/ml correctly classified 88% of the patients (odds ratio [OR] 85 [19 to 376], p < 0.0001), but a high negative predictive value (90%) was only obtained when the cutoff was lowered to 80 pg/ml. The etiologic value of BNP was low in patients with values between 80 and 300 pg/ml (OR 1.85 [0.4 to 7.8], p = 0.4) and also in patients who were studied very soon after onset of acute dyspnea. Among the 138 patients with assessable Doppler findings, a "restrictive" mitral inflow pattern had a diagnostic accuracy for CHF of 91% (OR 482 [77 to 3,011], p < 0.0001), regardless of the BNP level. CONCLUSIONS: Bedside BNP measurement and Doppler echocardiography are both useful for establishing the cause of acute dyspnea. However, Doppler analysis of the mitral inflow pattern was more accurate, particularly in patients with intermediate BNP levels or "flash" pulmonary edema.     

Usefulness of B-type natriuretic peptide (BNP) for the diagnosis of new-onset heart failure with a preserved left ventricular systolic function in longstanding hypertensive patients with acute dyspnea

BACKGROUND: B-type natriuretic peptide (BNP) has been largely validated in the etiologic diagnosis of acute dyspnea. Nevertheless, its reliability in the setting of a preserved left ventricular systolic function (ejection fraction >50%) has not been adequately established. OBJECTIVE: the study addressed the usefulness of BNP in the diagnosis of new-onset heart failure with a preserved systolic function in hypertensive patients hospitalized for acute dyspnea. METHODS: 59 consecutive hypertensive patients without history of heart failure and coronary disease were included. BNP was measured at presentation with the Triage system. Noninvasive estimation of left ventricular filling pressures by bedside tissue Doppler echocardiography at presentation was incorporated in the diagnostic criteria. RESULTS: the 30 patients with heart failure were not significantly different from the 29 patients with noncardiac cause of acute dyspnea regarding age, gender, body mass index and ejection fraction. Median levels of BNP were significantly higher in heart failure (447 [245-644] versus 87 [43-139] pg/mL). By multivariate logistic regression analysis, BNP (odds ratio of 44, [3.6-531], p=0.003) provided independent and incremental diagnostic information over the clinical score of Boston criteria (2.25, [1.3-3.9], p=0.0037). A BNP value of >142 pg/mL (area under the ROC curve of 0.89, p<0.0001) was 93 sensitive and 79% specific for the diagnosis of heart failure in this setting. CONCLUSION: BNP is a reliable biomarker of new-onset heart failure with a preserved systolic function in hypertensive patients, in particular older, hospitalized for acute dyspnea and can be safely integrated in the diagnostic strategy.     

Accuracy of Nurse-Performed Lung Ultrasound in Patients With Acute Dyspnea: A Prospective Observational Study

In clinical practice lung ultrasound (LUS) is becoming an easy and reliable noninvasive tool for the evaluation of dyspnea. The aim of this study was to assess the accuracy of nurse-performed LUS, in particular, in the diagnosis of acute cardiogenic pulmonary congestion.We prospectively evaluated all the consecutive patients admitted for dyspnea in our Medicine Department between April and July 2014. At admission, serum brain natriuretic peptide (BNP) levels and LUS was performed by trained nurses blinded to clinical and laboratory data. The accuracy of nurse-performed LUS alone and combined with BNP for the diagnosis of acute cardiogenic dyspnea was calculated.Two hundred twenty-six patients (41.6% men, mean age 78.7 ± 12.7 years) were included in the study. Nurse-performed LUS alone had a sensitivity of 95.3% (95% CI: 92.6–98.1%), a specificity of 88.2% (95% CI: 84.0–92.4%), a positive predictive value of 87.9% (95% CI: 83.7–92.2%) and a negative predictive value of 95.5% (95% CI: 92.7–98.2%). The combination of nurse-performed LUS with BNP level (cut-off 400 pg/mL) resulted in a higher sensitivity (98.9%, 95% CI: 97.4–100%), negative predictive value (98.8%, 95% CI: 97.2–100%), and corresponding negative likelihood ratio (0.01, 95% CI: 0.0, 0.07).Nurse-performed LUS had a good accuracy in the diagnosis of acute cardiogenic dyspnea. Use of this technique in combination with BNP seems to be useful in ruling out cardiogenic dyspnea. Other studies are warranted to confirm our preliminary findings and to establish the role of this tool in other settings.     

Very Long-Term Prognostic Role of Admission BNP in Non-ST Segment Elevation Acute Coronary Syndrome

Background

BNP has been extensively evaluated to determine short- and intermediate-term prognosis in patients with acute coronary syndrome, but its role in long-term mortality is not known.

Objective

To determine the very long-term prognostic role of B-type natriuretic peptide (BNP) for all-cause mortality in patients with non-ST segment elevation acute coronary syndrome (NSTEACS).

Methods

A cohort of 224 consecutive patients with NSTEACS, prospectively seen in the Emergency Department, had BNP measured on arrival to establish prognosis, and underwent a median 9.34-year follow-up for all-cause mortality.

Results

Unstable angina was diagnosed in 52.2%, and non-ST segment elevation myocardial infarction, in 47.8%. Median admission BNP was 81.9 pg/mL (IQ range = 22.2; 225) and mortality rate was correlated with increasing BNP quartiles: 14.3; 16.1; 48.2; and 73.2% (p < 0.0001). ROC curve disclosed 100 pg/mL as the best BNP cut-off value for mortality prediction (area under the curve = 0.789, 95% CI= 0.723-0.854), being a strong predictor of late mortality: BNP < 100 = 17.3% vs. BNP ≥ 100 = 65.0%, RR = 3.76 (95% CI = 2.49-5.63, p < 0.001). On logistic regression analysis, age >72 years (OR = 3.79, 95% CI = 1.62-8.86, p = 0.002), BNP ≥ 100 pg/mL (OR = 6.24, 95% CI = 2.95-13.23, p < 0.001) and estimated glomerular filtration rate (OR = 0.98, 95% CI = 0.97-0.99, p = 0.049) were independent late-mortality predictors.

Conclusions

BNP measured at hospital admission in patients with NSTEACS is a strong, independent predictor of very long-term all-cause mortality. This study allows raising the hypothesis that BNP should be measured in all patients with NSTEACS at the index event for long-term risk stratification.     

Usefulness of B-type natriuretic peptide in emergency medicine

OBJECTIVES: Acute dyspnea is frequent in emergency medicine. The B-type natriuretic peptide is a polypeptide, released by ventricular myocytes directly proportional to wall tension, for lowering renin-angiotensin-aldosterone activation. Conversely, NT-proBNP has no physiological activity. BNP and NT-proBNP concentration closely correlate to various indicators of heart failure. CURRENT KNOWLEDGE AND KEY POINTS: Numerous studies have demonstrated high usefulness of BNP and NT-proBNP to diagnose heart failure, which is the main cause of acute dyspnea in emergency medicine. The diagnostic accuracy of BNP and NT-proBNP seems similar, and is higher than that of the emergency physician. Bedside dosages are now available, with high sensibility and specificity for the diagnosis of heart failure. For BNP, threshold value is ranging from 100 to 300 pg/ml in patients aged over 65 years; for NT-proBNP the threshold value is 1000 to 2000 pg/ml in elderly patients. Briefly, heart failure is unlikely when BNP is below 100 pg/ml (NT-proBNP<500 pg/ml), and very likely when BNP is higher than 400 pg/ml (or NT-proBNP>2000 pg/ml). FUTURE PROJECTS: Early rapid measurement of BNP could improved the evaluation and treatment of patients with acute dyspnea and reduce the total cost of treatment.     

Brain natriuretic peptide for prediction of Cheyne-Stokes respiration in heart failure patients

Cheyne-Stokes respiration (CSR) is indicative of adverse outcome in patients with chronic heart failure (CHF). We evaluated the use of brain natriuretic peptide (BNP) plasma levels to predict CSR in CHF patients. In this cross-sectional study, overnight polygraphy and cardiac work-up were performed and neurohumoral activation was determined in 102 consecutive CHF patients (25-82 years). Demographic characteristics did not significantly differ among patients with (n=38) or without CSR (n=64); BNP (median: 377 vs. 142 pg/ml, p<0.001) and norepinephrine levels (459+/-283 vs. 346+/-204 pg/ml, p=0.02) were significantly increased in patients with CSR. BNP concentrations were significantly associated with the central apnoea/hypopnoea index (y=253+/-5.3x; r=0.26, p=0.01). The area under the ROC curve that used BNP to predict CSR was 0.780 (95% CI: 0.688 to 0.873). Using established cut-off limits of BNP plasma levels, heart failure patients with BNP levels >500 pg/ml displayed a 13 fold increased risk of CSR (95% CI: 2.34-73.50; p=0.03) compared to patients with BNP levels <100 pg/ml. In multiple logistic regression analysis p(a)CO2 (point estimate 0.84, 95% CI: 0.72 to 0.98; p=0.02) and higher BNP class (point estimate 3.14, 95% CI: 1.38-7.144; p=0.006) emerged as parameters independently predicting the presence of CSR in our cohort of CHF patients. In conclusion, CSR is associated with neurohumoral activation in CHF patients. Specifically, BNP levels are associated with the severity of cardiac and sleep-related disease, and may be helpful in the diagnosis of CSR and more appropriate use of polysomnography in CHF patients.     

Accuracy of tissue Doppler echocardiography in the diagnosis of new-onset congestive heart failure in patients with levels of B-type natriuretic peptide in the midrange and normal left ventricular ejection fraction

BACKGROUND: Based on the hypothesis that it reflects left ventricular (LV) diastolic pressures, B-type natriuretic peptide (BNP) is largely utilized as first-line diagnostic complement in the emergency diagnosis of congestive heart failure (HF). The incremental diagnostic value of tissue Doppler echocardiography, a reliable noninvasive estimate of LV filling pressures, has been reported in patients with preserved LV ejection fraction and discrepancy between BNP levels and the clinical judgment, however, its clinical validity in such patients in the presence of BNP concentrations in the midrange, which may reflect intermediate, nondiagnostic levels of LV filling pressures, is unknown. METHODS: 34 patients without history of HF, presenting with acute dyspnea at rest, BNP levels of 100-400 pg/ml and normal LV ejection fraction were prospectively enrolled (17 with congestive HF and 17 with noncardiac cause). Tissue Doppler echocardiography was performed within 3 hours after admission. RESULTS: Unlike BNP (P = 0.78), Boston criteria (P = 0.0129), radiographic pulmonary edema (P = 0.0036) and average E/Ea ratio (P = 0.0032) were predictive of congestive HF by logistic regression analysis. In this clinical setting, radiographic pulmonary edema had a positive predictive value of 80% in the diagnosis of congestive HF. In patients without evidence of radiographic pulmonary edema, average E/Ea > 10 was a powerful predictor of congestive HF (area under the ROC curve of 0.886, P < 0.001, sensitivity 100% and specificity 78.6%). CONCLUSION: By better reflecting LV filling pressures, bedside tissue Doppler echocardiography accurately differentiates congestive HF from noncardiac cause in dyspneic patients with intermediate, nondiagnostic BNP levels and normal LV ejection fraction.     

B-type natriuretic peptide levels predict event-free survival in patients with implantable cardioverter defibrillators

INTRODUCTION: We examined whether B-type natriuretic peptide (BNP) levels predict outcome in heart failure patients with implantable cardioverter defibrillators (ICD) using a combined endpoint of malignant tachyarrhythmias, death or heart transplantation. METHODS AND RESULTS: BNP levels were measured in 123 ICD patients with chronic heart failure (age: 63+/-12 years, ejection fraction: 29+/-10%). After a median follow-up of 25 months, the combined endpoint was reached in 28 patients (first tachyarrhythmic event, n=16; death, n=11; heart transplantation, n=1). BNP levels were significantly lower in patients with event-free survival compared to patients reaching the combined endpoint of this study (median: 140 vs. 373 pg/ml; p<0.001). Multivariable Cox regression analysis revealed that BNP levels predict adverse outcome (RR 1.002 per pg/ml increment; 95% CI: 1.001-1.003; p<0.001) and use of beta-blockers was associated with favourable outcome (RR 0.319; 95% CI 0.151-0.670; p=0.004). LV ejection fraction (p=0.66) did not significantly predict event-free survival in multivariable analysis. CONCLUSIONS: BNP plasma levels are useful markers to predict event-free survival in ICD patients with heart failure. Of note, malignant tachyarrhythmias appear responsible for about 50% of fatal outcomes. Our findings suggest that determination of BNP plasma levels is more valuable than determining LV ejection fraction to anticipate event-free survival in this population.     

B-type natriuretic peptide and echocardiographic determination of ejection fraction in the diagnosis of congestive heart failure in patients with acute dyspnea

BACKGROUND: Echocardiography and B-type natriuretic peptide (BNP) are diagnostic tests for congestive heart failure (CHF), but an emergency diagnosis can be difficult. OBJECTIVE: To assess the diagnostic performance of BNP testing and echocardiographic assessment of left ventricular systolic function, separately and combined, for the identification of CHF in patients with acute dyspnea. DESIGN: Prospective, multinational, multicenter study. SETTING: Patients presenting to emergency departments in seven hospitals between June 1999 and December 2000. PATIENTS: A total of 1,586 patients with acute dyspnea. MAIN OUTCOME MEASURES: Echocardiographic determination of ejection fraction (EF) and point-of care BNP measurement for the diagnosis of CHF. RESULTS: Seven hundred nine of the 1,586 patients underwent echocardiography; 492 patients (69.4%) had a final diagnosis of CHF. Patients with CHF were older (68.5 years vs 61.6 years, p < 0.0001), had a lower EF (39.5% vs 56.1%, p < 0.0001), and a higher BNP (683 pg/mL vs 129 pg/mL, p < 0.0001) than patients without CHF. Area under the receiver operating characteristic (ROC) curve for the diagnosis of CHF was significantly higher for BNP (0.89) than for EF (0.78; area under the ROC curve difference, 0.12; p < 0.0001). The sensitivity of BNP > or = 100 pg/mL for the diagnosis of CHF was 89%, and specificity was 73%. Values for EF < or = 50% had a sensitivity of 70% and a specificity of 77%. Multivariate logistic regression analysis showed that, in combination with clinical, ECG, and chest radiograph data, BNP > or = 100 pg/mL and EF < or = 50% remained independent predictors of CHF (odds ratios, 32.1 and 6.2, respectively). The proportions of patients who were correctly classified were 67% for BNP alone, 55% for EF alone, 82% for the two variables together, and 97.3% when clinical, ECG, and chest radiograph data were added. CONCLUSION: BNP measurement was superior to two-dimensional echocardiographic determination of EF in identifying CHF, regardless of the threshold value. The two methods combined have marked additive diagnostic value.     

老年急性呼吸困难患者脑利钠肽测定结果分析

目的 探讨老年急性呼吸困难患者血浆脑利钠肽(BNP)水平对临床诊断的意义及时心功能不全的诊断价值.方法 选择老年(>65岁)急性呼吸困难患者95例,其中心源性呼吸困难患者73例,肺源性呼吸困难患者22例.应用快速床旁试验方法测定血浆BNP水平,确定血浆BNP界值.结果 心功能不全所致的急性呼吸困难患者血浆BNP水平明显升高,与肺源性呼吸困难患者比较有统计学意义(P<0.05).血浆BNP诊断界值在150 pg/mL时其特异性及敏感性均达85%左右,曲线下面积(AUC)为0.869.心源性呼吸困难组合并肾功能异常患者,其诊断界值在225 pg/mL.结论 血浆BNP对于老年急性心源性呼吸困难患者有诊断价值,其诊断界值为150 pg/mL.