Usefulness of aminoterminal pro-brain natriuretic peptide testing for the diagnostic and prognostic evaluation of dyspneic patients with diabetes mellitus seen in the emergency department (from the PRIDE Study).

Despite widespread testing, the utility of aminoterminal pro-brain natriuretic peptide (NT-pro-BNP) for diagnosis or risk assessment in patients with diabetes mellitus (DM) in the emergency department (ED) remains unclear. NT-pro-BNP was measured in subjects with dyspnea in the ED. A final diagnosis of acute heart failure (HF) was determined by blinded study physicians using all available hospital records. Vital status was assessed at 1 year; independent predictors of death were identified using Cox analysis. Of 599 subjects, 157 (26.2%) had DM, which was an independent predictor of a final diagnosis of acute HF. In patients diagnosed with acute HF, median concentrations of NT-pro-BNP were similar in patients with and without DM (4,784 vs 3,382 pg/ml, respectively, p = 0.93). In dyspneic subjects without acute HF, median concentrations of NT-pro-BNP were significantly higher in patients with DM (242 vs 115 pg/ml, p = 0.01), but this difference was no longer significant after adjusting for relevant covariates. The area under the curve for NT-pro-BNP to diagnose acute HF in subjects with DM was 0.94 (p <0.001). Using age-adjusted cutpoints, NT-pro-BNP was 92% sensitive and 90% specific for the diagnosis of HF in diabetic subjects. In diabetic patients, a NT-pro-BNP level > or =986 pg/ml was independently associated with an increased risk of death at 1 year (hazard ratio 3.42, 95% confidence interval 1.09 to 10.7, p <0.001). In conclusion, NT-pro-BNP testing offers valuable diagnostic and prognostic information in the evaluation of dyspneic patients with DM in the ED, using identical cutpoints as the population as whole.

Combination of D-dimer and amino-terminal pro-B-type natriuretic Peptide testing for the evaluation of dyspneic patients with and without acute pulmonary embolism.

CONTEXT: D-dimer concentration can be used to exclude a diagnosis of acute pulmonary embolism. However, clinicians frequently order unnecessary supplemental testing in patients with low concentrations of D-dimer. Elevations in natriuretic peptides have also been described in the setting of pulmonary embolism. OBJECTIVE: We investigated the integrative role of D-dimer with amino-terminal pro-B-type natriuretic peptide for the evaluation of patients with and without acute pulmonary embolism. DESIGN: Patients were selected for analysis from a previous study in which levels of D-dimer and amino-terminal pro-B-type natriuretic peptide were measured. The presence of pulmonary embolism was determined by computed tomographic angiography. RESULTS: The median levels of D-dimer were significantly higher in patients with acute pulmonary embolism. Similarly, the median levels of amino-terminal pro-B-type natriuretic peptide were higher in patients with pulmonary embolism. CONCLUSIONS: The Roche Tina-quant D-Dimer immunoturbidimetric assay provides a high negative predictive value and can be used to exclude acute pulmonary embolism in patients with dyspnea. Measurement of amino-terminal pro-B-type natriuretic peptide in addition to D-dimer improves specificity for acute pulmonary embolism without sacrificing negative predictive value. A combination of both markers may offer reassurance for excluding acute pulmonary embolism, and thus avoid redundant, expensive confirmatory tests.

Cost-effectiveness of using N-terminal pro-brain natriuretic peptide to guide the diagnostic assessment and management of dyspneic patients in the emergency department.

The cost-effectiveness of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) in dyspneic patients in emergency departments (EDs) is unknown. The objective of this study was to assess the cost-effectiveness of NT-pro-BNP testing for the evaluation and initial management of patients with dyspnea in the ED setting. A decision model was developed to evaluate the cost-effectiveness of diagnostic assessment and patient management guided by NT-pro-BNP, compared with standard clinical assessment. The model includes the diagnostic accuracy of the 2 strategies for congestive heart failure and resulting events at 60-day follow-up. Clinical data were obtained from a prospective blinded study of 599 patients presenting to the ED with dyspnea. Costs were based on the Massachusetts General Hospital cost accounting database. The model predicted serious adverse events during follow-up (i.e., urgent care visits, repeat ED presentations, rehospitalizations) and direct medical costs for echocardiograms and hospitalizations. NT-pro-BNP-guided assessment was associated with a 1.6% relative reduction of serious adverse event risk and a 9.4% reduction in costs, translating into savings of $474 per patient, compared with standard clinical assessment. In a sensitivity analysis considering mortality, NT-pro-BNP testing was associated with a 1.0% relative reduction in post-discharge mortality. The optimal use of NT-pro-BNP guidance could reduce the use of echocardiography by up to 58%, prevent 13% of initial hospitalizations, and reduce hospital days by 12%. In conclusion, on the basis of this model, the use of NT-pro-BNP in the diagnostic assessment and subsequent management of patients with dyspnea in the ED setting could lead to improved patient care while providing substantial cost savings to the health care system.

Utility of amino-terminal pro-brain natriuretic peptide testing for prediction of 1-year mortality in patients with dyspnea treated in the emergency department.

BACKGROUND: Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is useful for diagnosis and triage of patients with dyspnea, but its role for predicting outcomes in such patients remains undefined. METHODS: A total of 599 breathless patients treated in the emergency department were prospectively enrolled, and a sample of blood was obtained for NT-proBNP measurements. After 1 year, the vital status of each patient was ascertained, and the association between NT-proBNP values at presentation and mortality was assessed. RESULTS: At 1 year, 91 patients (15.2%) had died. Median NT-proBNP concentrations at presentation among decedents were significantly higher than those of survivors (3277 vs 299 pg/mL; P<.001). The optimal NT-proBNP cut point for predicting 1-year mortality was 986 pg/mL. In a multivariable model, an NT-proBNP concentration greater than 986 pg/mL at presentation was the single strongest predictor of death at 1 year (hazard ratio [HR], 2.88; 95% confidence interval, 1.64-5.06; P<.001), independent of a diagnosis of heart failure. Other factors associated with death included age (by decade; HR, 1.20), heart rate (by decile; HR, 1.13), urea nitrogen level (by decile; HR, 1.20), systolic blood pressure less than 100 mm Hg (HR, 1.94), heart murmur (HR, 1.92), and New York Heart Association classification (HR, 1.38 for each increase in class). The NT-proBNP concentration alone had an area under the receiver operating characteristic curve (AUC) of 0.76 for predicting mortality; the other significant covariates combined had an AUC of 0.80. The final model for predicting death, combining NT-proBNP with other covariates associated with mortality, had a superior AUC of 0.82. CONCLUSION: In addition to assisting in emergency department diagnosis and triage, NT-proBNP concentrations at presentation are strongly predictive of 1-year mortality in dyspneic patients.

A validated clinical and biochemical score for the diagnosis of acute heart failure: the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) Acute Heart Failure Score.

BACKGROUND: No method integrating amino-terminal pro-brain natriuretic peptide (NT-proBNP) testing with clinical assessment for the evaluation of patients with suspected acute heart failure (HF) has been described. METHODS: Amino-terminal pro-brain natriuretic peptide results and clinical factors from 599 patients with dyspnea were analyzed. The beta coefficients of the 8 independent predictors of HF were used to assign a weighted integeric score for predictor. The sum of these integers provided a diagnostic HF "score" for each patient. Receiver operating characteristic curve analysis determined the optimal cut point for the diagnosis of acute HF. The performance of the score was evaluated in the development cohort and subsequently in a patient population from a separate clinical trial of patients with dyspnea conducted in Christchurch, New Zealand. RESULTS: Eight factors comprised the score: elevated NT-proBNP (4 points), interstitial edema on chest x-ray (2 points), orthopnea (2 points), absence of fever (2 points), loop diuretic use, age > 75 years, rales, and absence of cough (all 1 point). Median scores in patients with acute HF were higher than those without acute HF (9 vs 3 points, P < .001). At a cut point of > or = 6 points, the score had a sensitivity of 96% and a specificity of 84% for the diagnosis of acute HF (P < .001). The score improved diagnostic accuracy over NT-proBNP testing alone and retained discriminative capacity in patients in whom clinical uncertainty was present. Lastly, the accuracy of the score was validated in the external data set of patients with suspected acute HF. CONCLUSION: We report a simple and accurate scoring system combining NT-proBNP testing and clinical assessment for the diagnosis or exclusion of acute HF in patients with dyspnea.

Effect of body mass index on natriuretic peptide levels in patients with acute congestive heart failure: a ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) substudy.

BACKGROUND: Obesity is associated with lower B-type natriuretic peptide (BNP) levels in healthy individuals and patients with chronic congestive heart failure (CHF). Neither the mechanism of natriuretic peptide suppression in the obese patient nor whether obesity affects natriuretic peptide levels among patients with acute CHF is known. METHODS: The associations of amino-terminal pro-BNP (NT-proBNP), BNP, and body mass index (BMI) were examined in 204 subjects with acute CHF. Multivariable regression analyses were performed to identify factors independently related to NT-proBNP and BNP levels. RESULTS: Across clinical strata of normal (<25 kg/m2), overweight (25-29.9 kg/m2), and obese (> or =30 kg/m2) patients, median NT-proBNP and BNP levels decreased with increasing BMI (both P values < .001). In multivariable analyses adjusting for covariates known to affect BNP levels, the inverse relationship between BMI and both NT-proBNP and BNP remained ( P < .05 for both). Using a cut point of 900 pg/mL, NT-proBNP was falsely negative in up to 10% of CHF cases in overweight patients (25-29.9 kg/m2) and 15% in obese patients (> or =30 kg/m2). Using the standard cut point of 100 pg/mL, BNP testing was falsely negative in 20% of CHF cases in both overweight and obese patients. The assays for NT-proBNP and BNP exhibited similar overall sensitivity for the diagnosis of CHF. CONCLUSIONS: When adjusted for relevant covariates, compared with normal counterparts, overweight and obese patients with acute CHF have lower circulating NT-proBNP and BNP levels, suggesting a BMI-related defect in natriuretic peptide secretion. NT-proBNP fell below the diagnostic cutoff for CHF less often than BNP in overweight and obese individuals; however, when used as a diagnostic tool to identify CHF in such patients, both markers may have reduced sensitivity.

The N-terminal Pro-BNP investigation of dyspnea in the emergency department (PRIDE) study.

The utility of aminoterminal pro-brain natriuretic peptide (NT-proBNP) testing in the emergency department to rule out acute congestive heart failure (CHF) and the optimal cutpoints for this use are not established. We conducted a prospective study of 600 patients who presented in the emergency department with dyspnea. The clinical diagnosis of acute CHF was determined by study physicians who were blinded to NT-proBNP results. The primary end point was a comparison of NT-proBNP results with the clinical assessment of the managing physician for identifying acute CHF. The median NT-proBNP level among 209 patients (35%) who had acute CHF was 4,054 versus 131 pg/ml among 390 patients (65%) who did not (p <0.001). NT-proBNP at cutpoints of >450 pg/ml for patients <50 years of age and >900 pg/ml for patients >or=50 years of age were highly sensitive and specific for the diagnosis of acute CHF (p <0.001). An NT-proBNP level <300 pg/ml was optimal for ruling out acute CHF, with a negative predictive value of 99%. Increased NT-proBNP was the strongest independent predictor of a final diagnosis of acute CHF (odds ratio 44, 95% confidence interval 21.0 to 91.0, p <0.0001). NT-proBNP testing alone was superior to clinical judgment alone for diagnosing acute CHF (p = 0.006); NT-proBNP plus clinical judgment was superior to NT-proBNP or clinical judgment alone. NT-proBNP measurement is a valuable addition to standard clinical assessment for the identification and exclusion of acute CHF in the emergency department setting.

A clinical and biochemical critical pathway for the evaluation of patients with suspected acute congestive heart failure: The ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) algorithm.

Dyspnea is a primary clinical manifestation of acute congestive heart failure (CHF) among patients presenting to the emergency department (ED). Unfortunately, other critical illnesses, including acute coronary syndromes, pulmonary embolism, chronic obstructive pulmonary disease, and pneumonia, may present with clinical symptoms and signs similar to acute CHF. N-terminal pro-brain natriuretic peptide (NT-proBNP) has proven to be a powerful tool in the diagnostic assessment of dyspnea as a result of its ability to confirm or exclude the presence of acute CHF. However, many of the disorders that mimic acute CHF may result in elevated NT-proBNP levels as well. Results from the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) study recently demonstrated that a strategy integrating NT-proBNP testing into routine clinical assessment demonstrated a better diagnostic yield than each strategy used in isolation. We present a diagnostic algorithm integrating NT-proBNP testing with clinical assessment for use in routine clinical practice.