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Biomedical subjects

Paul Clopton

Publications and source records attributed to Paul Clopton.

At least 19 recordsLinked to original sources

Increased cardiac adenylyl cyclase expression is associated with increased survival after myocardial infarction.

BACKGROUND: Cardiac-directed expression of adenylyl cyclase type VI (AC(VI)) in mice results in structurally normal hearts with normal basal heart rate and function but increased responses to catecholamine stimulation. We tested the hypothesis that increased left ventricular (LV) AC(VI) content would increase mortality after acute myocardial infarction (MI). METHODS AND RESULTS: Transgenic mice with cardiac-directed AC(VI) expression and their transgene-negative littermates (control) underwent coronary ligation, and survival, infarct size, and LV size and function were assessed 1 to 7 days after MI. Mice with increased AC(VI) expression had increased survival (control 41%, AC(VI) 74%; P = 0.004). Infarct size and myocardial apoptotic rates were similar in AC(VI) and control mice; however, AC(VI) mice had less LV dilation (P < 0.001) and increased ejection fractions (P < 0.03). Three days after MI, studies in isolated perfused hearts showed that basal LV +dP/dt was similar, but graded dobutamine infusion was associated with a more robust LV contractile response in AC(VI) mice (P < 0.05). Increased LV function was associated with increases in cAMP generation (P = 0.0002), phospholamban phosphorylation (P < 0.04), sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) affinity for calcium (P < 0.015), and reduced AV block (P = 0.04). CONCLUSIONS: In acute MI, increased cardiac AC(VI) content attenuates adverse LV remodeling, preserves LV contractile function, and reduces mortality.

Adenylyl Cyclases↗

How obesity affects the cut-points for B-type natriuretic peptide in the diagnosis of acute heart failure. Results from the Breathing Not Properly Multinational Study.

BACKGROUND: B-type natriuretic peptide (BNP) is valuable in diagnosing heart failure (HF), but its utility in obese patients is unknown. Studies have suggested a cut-point of BNP > or = 100 pg/mL for the diagnosis of HF; however, there is an inverse relation between BNP levels and body mass index. We evaluated differential cut-points for BNP in diagnosing acute HF across body mass index levels to determine whether alternative cut-points can improve diagnosis. METHODS: The Breathing Not Properly Multinational Study was a 7-center, prospective study of 1586 patients who presented to the Emergency Department with acute dyspnea. B-type natriuretic peptide was measured on arrival. Height and weight data were available for 1368 participants. The clinical diagnosis of HF was adjudicated by 2 independent cardiologists who were blinded to BNP results. RESULTS: Heart failure was the final diagnosis in 46.1%. Mean BNP levels (pg/mL) in lean, overweight/obese, and severely/morbidly obese patients were 643, 462, and 247 for patients with acute HF, and 52, 35, and 25 in those without HF, respectively (P < .05 for all comparisons except 35 vs 25). B-type natriuretic peptide cut-points to maintain 90% sensitivity for a HF diagnosis were 170 pg/mL for lean subjects, 110 pg/mL for overweight/obese subjects, and 54 pg/mL in severely/morbidly obese patients. CONCLUSIONS: Body mass index influences the selection of cut-points for BNP in diagnosing acute HF. A lower cut-point (BNP > or = 54 pg/mL) should be used in severely obese patients to preserve sensitivity. A higher cut-point in lean patients (BNP > or = 170 pg/mL) could be used to increase specificity.

Acute Disease↗

Gray zone BNP levels in heart failure patients in the emergency department: results from the Rapid Emergency Department Heart Failure Outpatient Trial (REDHOT) multicenter study.

OBJECTIVES: The study purpose was to examine "gray zone" B-type natriuretic peptide (BNP) levels (100-500 pg/mL) in terms of associated clinical factors, perceived severity, and outcomes in patients with established congestive heart failure (CHF). BACKGROUND: Although gray zone BNP levels may have diagnostic ambiguity, the implications of these levels in patients with an established diagnosis of CHF have not been examined. METHODS: REDHOT was a national prospective study in which 464 patients seen in the emergency department with dyspnea had BNP levels drawn. Entrance criteria included a BNP > 100 pg/mL; however, physicians were blinded to the actual BNP level. Patients were followed up for 90 days. RESULTS: Thirty-three percent had gray zone BNP levels. There was no difference in perceived New York Heart Association class (P = .32) or admission rates (P = .76) between the gray zone and non-gray zone groups; 62% of patients with a gray zone BNP were identified as class III or IV CHF. Despite this perceived severity, the 90-day event rate was lower in the gray zone group (19.2% vs 32.9%, respectively, P = .002). Although patients in the gray zone had more symptoms of concomitant pulmonary disease, multivariate analysis could not demonstrate any variable that worsened the prognosis of patients with a gray zone BNP level. CONCLUSIONS: In patients with established CHF, those with gray zone BNP levels have a better prognosis than those with non-gray zone levels despite being perceived by physicians as having New York Heart Association class III or IV CHF.

Aged↗

Impact of the history of congestive heart failure on the utility of B-type natriuretic peptide in the emergency diagnosis of heart failure: results from the Breathing Not Properly Multinational Study.

PURPOSE: B-type natriuretic peptide is known to correlate with hemodynamic state, presence and severity of congestive heart failure, and prognosis. Although low-range B-type natriuretic peptide less than 100 pg/mL has a high negative predictive value (90%), and high-range B-type natriuretic peptide greater than 500 pg/mL has a high positive predictive value (87%), there remains some ambiguity in the interpretation of results in the medium range (100-500 pg/mL). We hypothesized that taking into account the history of congestive heart failure along with other clinical variables would be helpful in this range of B-type natriuretic peptide levels. METHOD: The Breathing Not Properly Multicenter Study was an international, 7-center, prospective study including 1475 patients with a mean age of 63 years (57% were male, and 54% were female); 35% of patients with a history of congestive heart failure were enrolled, and a final diagnosis of congestive heart failure was made in 46%. The index criteria was defined as positive if any 2 index findings (ie, history of coronary artery disease, lower extremity edema, pulmonary edema, cephalization of the pulmonary arteries, and cardiomegaly) were present. RESULTS: The interval likelihood ratios (LR) for low, medium, and high B-type natriuretic peptide ranges are 0.13, 1.85, and 8.1, respectively. For medium B-type natriuretic peptide levels a positive history of congestive heart failure makes the diagnosis of congestive heart failure more probable with a cumulative LR of 4.3. Also in this range a positive index criterion was strongly indicative of congestive heart failure even in the absence of a history of congestive heart failure (LR 3.3). Where there are both a positive history of congestive heart failure and a positive index criteria for the medium B-type natriuretic peptide group, the cumulative LR (10.2) is similar to that of a high B-type natriuretic peptide level (8.1). CONCLUSION: Even in the medium range (100-500 pg/mL), when using the history of congestive heart failure and index criteria, B-type natriuretic peptide can be a powerful diagnostic tool in the hands of clinicians in the emergency department.

Aged↗

B-type natriuretic peptide (BNP) levels and ethnic disparities in perceived severity of heart failure: results from the Rapid Emergency Department Heart Failure Outpatient Trial (REDHOT) multicenter study of BNP levels and emergency department decision making in patients presenting with shortness of breath.

BACKGROUND: Previous studies have shown that in patients presenting to the emergency department (ED) with heart failure, there is a disconnect between the perceived severity of congestive heart failure (CHF) by physicians and the severity as determined by B-type natriuretic peptide (BNP) levels. Whether ethnicity plays a role in this discrepancy is unknown. METHODS AND RESULTS: The Rapid Emergency Department Heart Failure Outpatient Trial (REDHOT) was a 10-center trial of 464 patients seen in the ED with acute dyspnea and BNP level higher than 100 pg/mL on arrival. Physicians were blinded to BNP levels. Patients were followed for 90 days after discharge. A total of 151 patients identified themselves as white (32.5%) and 294 as black (63.4%). Of these, 90% were hospitalized. African Americans were more likely to be perceived as New York Heart Association class I or II than whites (P = .01). Blacks who were discharged from the ED had higher median BNP levels than whites who were discharged (1293 vs. 533, P = .004). The median BNP of blacks who were discharged was actually higher than the median BNP of blacks who were admitted (1293 vs. 769, P = .04); the same did not hold true for whites. BNP was predictive of 90-day outcome in both blacks and whites; however, perceived severity of CHF, race, and ED disposition did not contribute to the prediction of events. CONCLUSION: In patients presenting to the ED with heart failure, the disconnect between perceived severity of CHF and severity as determined by BNP levels is most pronounced in African Americans.

Black or African American↗

Correlation and prognostic utility of B-type natriuretic peptide and its amino-terminal fragment in patients with chronic kidney disease.

This study compared the correlation and prognostic utility of B-type natriuretic peptide (BNP) and the N-terminal fragment of proBNP (NT-proBNP) in 171 outpatients with renal dysfunction. The NT-proBNP correlated well with BNP in all cases (r = 0.911; P pound .01), regardless of degree of renal impairment or type of left ventricular dysfunction. BNP and NT-proBNP concentrations (P < .005) and their ratios (P pound .01) increased as the glomerular filtration rate (GFR) declined, indicating a greater effect of GFR on NT-proBNP levels. Both natriuretic peptide levels were higher in patients with systolic dysfunction (P < .05) compared with patients with normal echocardiograms. In contrast, BNP and NT-proBNP levels were below the diagnostic cutoffs for congestive heart failure exacerbations in patients with normal heart function or diastolic dysfunction, with no statistical difference between these groups (P = .99). Both peptides are useful prognostic tools for predicting mortality and cardiac hospitalization in renal patients.

Aged↗

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.

Acute Disease↗

Relationship of B-type natriuretic peptide and anemia in patients with and without heart failure: a substudy from the Breathing Not Properly (BNP) Multinational Study.

While anemia is a significant risk factor for poor outcomes in patients with heart failure (HF), it is not in defined guidelines for HF assessment. B-type natriuretic peptide (BNP) is a marker for diagnosis and management of patients with HF. We determined the incidence of anemia in patients with HF and the relationship between BNP and hemoglobin (Hgb) levels in patients with and without HF. Results from the Breathing Not Properly Multinational Trial consisted of 1,586 patients presenting to the emergency department (ED) with dyspnea. Because renal insufficiency is a confounding variable for BNP, patients with a creatinine of >or=2.0 mg/dL were excluded. The remaining data were evaluated from 620 non-HF patients (337 M, 283 F) and 547 HF patients (299 M, 248 F). The New York Heart Association (NYHA) HF classification and ejection fraction by echocardiography were assessed for HF patients. Blood was tested for Hgb, BNP, and creatinine. Using World Health Organization criteria for anemia, we observed that HF patients in NYHA class III or IV had lower mean Hgb levels (12.5 g/dL, P < 0.05) and a higher incidence of anemia (48.2%, P < 0.05) than did HF patients in class I or II (13.4 g/dL and 33.9%, respectively). There was no correlation between Hgb and log BNP for females without HF or the aggregate of all HF patients. In contrast, a significant inverse correlation was observed for males without HF (P < 0.001). Although there were differences in the BMI, age, and estimated glomerular filtration rate (eGFR) versus Hgb observed in this group, the log BNP correlation remained significant after multivariate analysis. A significant inverse correlation for log BNP and Hgb were also observed for diastolic (EF >or= 50) HF (P < 0.05) that was also not accounted for by the BMI, age, or eGFR. The presence of anemia is associated with worsening HF at ED presentation. For males without HF and diastolic HF patients of both genders, a low Hgb may be a confounding variable toward increasing BNP. Among systolic HF patients, the presence of a low hemoglobin concentration is not a factor in the interpretation of BNP results.

Anemia↗

Effect of nesiritide in combination with standard therapy on serum concentrations of natriuretic peptides in patients admitted for decompensated congestive heart failure.

OBJECTIVE: The objective of this study is to determine the effect of nesiritide (human recombinant BNP [hBNP]) in combination with standard therapy on the concentrations of B-type natriuretic peptide (BNP) and N-terminal probrain natriuretic peptide (NT-proBNP). BACKGROUND: B-type natriuretic peptide is synthesized in cardiac ventricles as a prohormone (108 amino acids) and when released into peripheral circulation is cleaved into the active hormone BNP (amino acids 77-108) and an inactive amino terminal fragment NT-proBNP (amino acids 1-76). METHODS: Three groups of patients with acutely decompensated congestive heart failure (CHF) received nesiritide for 24, 36, or 48 hours (n = 5, 7, and 7, respectively) in addition to standard therapy. Serial blood samples were collected. B-type natriuretic peptide and NT-proBNP were measured. RESULTS: To correct for positive skew, natriuretic peptide concentrations were log transformed. The mean baseline (prenesiritide), 6-, 12-, and 24-hour infusion, and 6-, 12-, and 24-hour postinfusion concentrations of BNP were 1000, 2300, 2200, 1700, 580, 640, and 740 pg/mL, respectively (n = 19). The 6- and 12-hour postinfusion concentrations of BNP were significantly lower (< 0.05) than baseline. The mean baseline, 60-, 120-, and 24-hour infusion, and 6-, 12-, and 24-hour postinfusion concentrations of NT-proBNP were 6600, 6500, 5800, 4300, 4100, 4300, and 5100 pg/mL, respectively (n = 19). From the time point 24 hours after initiation of therapy through 12 hours postinfusion, the mean NT-proBNP concentration was significantly (< 0.05) lower than baseline. CONCLUSION: Nesiritide, in combination with standard therapy, significantly lowered the endogenous concentrations of natriuretic peptides during infusion and after dosing was completed.

Adult↗

Diagnostic ability of B-type natriuretic peptide and impedance cardiography: testing to identify left ventricular dysfunction in hypertensive patients.

BACKGROUND: Patients with hypertension are at high risk for the development of left ventricular dysfunction (LVD). Echocardiography is considered to be the gold standard for diagnosis of LVD; but its cost, complexity, and availability prevents its use for frequent evaluation. Brain natriuretic peptide (BNP) and N-terminal BNP (NT-BNP) can identify heart failure in dyspneic patients. Impedance cardiography (ICG) is a noninvasive method of measuring hemodynamic and electromechanical timing parameters. The objective of this study was to determine the ability of BNP, NT-BNP, and ICG to detect the presence of LVD in patients with hypertension. METHODS: A convenience sample of subjects undergoing echocardiography who had a history of hypertension or current systolic blood pressure >/=140 mm Hg were enrolled and retrospectively evaluated. Patients with known LVD were excluded. Diagnosis of LVD was determined by the presence of systolic or diastolic dysfunction, valvular or wall motion abnormalities, or left ventricular hypertrophy. RESULTS: A total of 193 subjects were enrolled: 189 men and four women, age 68.8 +/- 11.7 years. Multivariate regression analysis of history and symptoms, BNP, and ICG parameters identified significant predictor variables for LVD including cardiac index (P = .005), left cardiac work index (P = .008), BNP (P = .017), arrhythmia (P = .023), angina (P = .034), and systemic vascular resistance (P = .048). Receiver operating characteristic (ROC) analysis determined the area under the ROC curve (AUC) of BNP (0.60), NT-BNP (0.67), ICG velocity index (0.66), composite ICG (0.66), ICG combined with BNP (0.70), and ICG combined with NT-BNP (0.73). CONCLUSIONS: In this high-risk hypertensive population, BNP, NT-BNP, and ICG were useful to identify the presence of LVD. The use of ICG with natriuretic peptide testing may improve the ability to detect LVD.

Aged↗

Predictors of elevated B-type natriuretic peptide concentrations in dyspneic patients without heart failure: an analysis from the breathing not properly multinational study.

STUDY OBJECTIVE: B-type natriuretic peptide (BNP) is an established tool for the diagnosis of acute congestive heart failure in patients presenting with dyspnea. Some patients have moderately elevated BNP levels (ie, 100 to 500 pg/mL) in the absence of acute congestive heart failure. The objective of the current study was to identify independent predictors of elevated BNP concentrations in the absence of congestive heart failure. METHODS: We studied 781 patients without acute congestive heart failure and BNP levels 0 to 500 pg/mL drawn from a cohort of 1,586 patients with acute dyspnea who had BNP levels measured on emergency department arrival. Two cardiologists blinded to BNP results reviewed all clinical data and categorized patients according to whether they had acute congestive heart failure or not. RESULTS: Independent predictors of elevated BNP levels (ie, >100 pg/mL) were a medical history of atrial fibrillation, radiographic cardiomegaly, decreased blood hemoglobin concentration, decreased body mass index, and increased age. CONCLUSION: Knowledge of these commonly obtained variables should aid clinicians in the interpretation of moderately elevated BNP results in patients presenting with acute dyspnea in the emergency department.

Aged↗

Primary results of the Rapid Emergency Department Heart Failure Outpatient Trial (REDHOT). A multicenter study of B-type natriuretic peptide levels, emergency department decision making, and outcomes in patients presenting with shortness of breath.

OBJECTIVES: The purpose of this study was to examine the relationships among B-type natriuretic peptide (BNP) levels within the diagnostic range, perceived congestive heart failure (CHF) severity, clinical decision making, and outcomes of the CHF patients presenting to emergency department (ED). BACKGROUND: Since BNP correlates with the presence of CHF, disease severity, and prognosis, we hypothesized that BNP levels in the diagnostic range offer value independent of physician decision making with regard to critical outcomes in emergency medicine. METHODS: The Rapid Emergency Department Heart failure Outpatient Trial (REDHOT) study was a 10-center trial in which patients seen in the ED with shortness of breath were consented to have BNP levels drawn on arrival. Entrance criteria included a BNP level >100 pg/ml. Physicians were blinded to the actual BNP level and subsequent BNP measurements. Patients were followed up for 90 days after discharge. RESULTS: Of the 464 patients, 90% were hospitalized. Two-thirds of patients were perceived to be New York Heart Association (NYHA) functional class III or IV. The BNP levels did not differ significantly between patients who were discharged home from the ED and those admitted (976 vs. 766, p = 0.6). Using logistic regression analysis, an ED doctor's intention to admit or discharge a patient had no influence on 90-day outcomes, while the BNP level was a strong predictor of 90-day outcome. Of admitted patients, 11% had BNP levels <200 pg/ml (66% of which were perceived NYHA functional class III or IV). The 90-day combined event rate (CHF visits or admissions and mortality) in the group of patients admitted with BNP <200 pg/ml and >200 pg/ml was 9% and 29%, respectively (p = 0.006). CONCLUSIONS: In patients presenting to the ED with heart failure, there is a disconnect between the perceived severity of CHF by ED physicians and severity as determined by BNP levels. The BNP levels can predict future outcomes and thus may aid physicians in making triage decisions about whether to admit or discharge patients. Emerging clinical data will help further refine biomarker-guided outpatient therapeutic and monitoring strategies involving BNP.

Biomarkers↗

Prognostic role of B-type natriuretic peptide levels in patients with type 2 diabetes mellitus.

OBJECTIVES: We hypothesized that B-type natriuretic peptide (BNP) levels can predict cardiac mortality in diabetic patients. BACKGROUND: Detection of cardiovascular disease in diabetics can be difficult until overt events occur. METHODS: A total of 482 diabetics (majority male with type 2 diabetes) at the Veterans Affairs Medical Center San Diego were divided into two groups: 1) referred patients for echocardiogram on the basis of clinical suspicion of cardiac dysfunction (referred [R], n = 180); 2) patients randomly selected from the diabetic clinic without any suspicion of cardiac dysfunction (not referred [N-R], n = 302). We examined cardiac events and all-cause mortality in relation to initial BNP levels during the follow-up. RESULTS: A total of 71 (14.7%) patients died during this period: 52 of 180 (29%) in the R group (30 of 52 [58%] cardiac, 10 of 52 [19%] non-cardiac, 2 of 52 [4%] renal, 10 of 52 [19%] unknown cause) and 19 of 302 (6%) in N-R group (6 of 19 [32%] cardiac). The median BNP level in the R and N-R groups who died of cardiac, non-cardiac, and unknown cause was 537 and 87, 80 and 53, and 343 and 38 pg/ml, respectively. The receiver-operating characteristic (ROC) values for mortality in two groups in relation to BNP revealed the area under the curve to be 0.720 and 0.691, respectively (p < 0.01 in both). Among commonly used prognostic indicators in diabetics, only the ROC for triglycerides was significant. The most accurate cut-point in both the N-R group (87%) and R group (61%) was 120 pg/ml of BNP. Cox regression analysis showed BNP to be the most significant predictor of all-cause mortality in the R group. There was a marked decrease in survival in the patient group with BNP >120 pg/ml. CONCLUSIONS: B-type natriuretic peptide appears to be a reliable predictor of future cardiac and all-cause mortality in diabetic patients.

Adult↗

Intracoronary adenovirus encoding adenylyl cyclase VI increases left ventricular function in heart failure.

BACKGROUND: We tested the hypothesis that intracoronary delivery of an adenovirus encoding adenylyl cyclase type VI (Ad.AC(VI)) would be associated with increased left ventricular (LV) function in pigs with congestive heart failure. METHODS AND RESULTS: Pigs (52+/-6 kg; n=16) underwent placement of pacemakers, LV pressure transducers, and left atrial and aortic catheters. Physiological and echocardiographic studies were obtained from conscious animals 13 days later, and pacing was initiated (220 bpm). Seven days later, measures of LV function were reduced, documenting severe LV dysfunction and dilation. Pigs then received intracoronary Ad.AC(VI) (1.4x10(12) vp; n=7) or saline (PBS; n=9) (randomized, blinded), with concomitant infusion of nitroprusside (50 microg/min, 6.4 minutes) to increase gene transfer. Pacing was continued for 14 days, and final studies were obtained. The a priori key end point was change in LV dP/dt during isoproterenol infusion (pre-Ad.AC(VI) value minus value after 21 days of pacing). Pigs receiving Ad.AC(VI) showed a smaller decrease in both LV +dP/dt (P=0.0014) and LV -dP/dt (P=0.0008). Serial echocardiography showed that Ad.AC(VI) treatment was associated with increased LV function and reduced LV dilation and that end-systolic wall stress was reduced. AC-stimulated cAMP production was increased 1.7-fold in LV samples from Ad.AC(VI)-treated pigs (P=0.006), and B-type natriuretic peptide was reduced (0.035). Gene transfer was confirmed by polymerase chain reaction. CONCLUSIONS: AC(VI) gene transfer increases LV function and attenuates deleterious LV remodeling in congestive heart failure.

Adenoviridae↗

Utility of B-type natriuretic peptide in predicting postoperative complications and outcomes in patients undergoing heart surgery.

OBJECTIVES: The purpose of the present study was to assess whether preoperative and postoperative B-type natriuretic peptide (BNP) levels could be used as predictors of postoperative complications and outcomes in patients after open-heart surgery. BACKGROUND: A variety of multifactor indexes have been proposed for preoperative risk assessment of patients undergoing cardiac surgery, but they have shown limited ability and utility in accurately predicting postoperative complications, hospital stay, and mortality. METHODS: Subjects consisted of 98 male patients (63 +/- 9.1 years) undergoing open-heart surgery at the San Diego Veterans Administration Health System during a 19-month period. B-type natriuretic peptide levels were analyzed, and postoperative data recorded. RESULTS: There was a higher preoperative BNP level in patients requiring the use of intra-aortic balloon pumps (IABPs) (mean BNP = 387 +/- 112 pg/ml vs. 181 +/- 25 pg/ml), in patients who died within one year (357 +/- 93 pg/ml vs. 184 +/- 26 pg/ml), and in patients with postoperative hospital stays of 10 days or more (307 +/- 68 pg/ml vs. 179 +/- 27 pg/ml). Receiver operating characteristic curves demonstrated preoperative BNP levels as predictors of postoperative IABP use, hospital stay 385 pg/ml predict the postoperative complications and one-year mortality after heart surgery. Postoperatively, elevated peak BNP levels and elevated change to peak BNP levels were associated with prolonged hospital stay and mortality within one year.

Aged↗

Diagnostic value of B-Type natriuretic peptide and chest radiographic findings in patients with acute dyspnea.

PURPOSE: To compare chest radiographic findings and circulating B-type natriuretic peptide (BNP) levels as an adjunct to clinical findings in the diagnosis of heart failure in patients presenting with acute dyspnea. METHODS: The diagnostic performance of radiographic evidence of cardiomegaly/redistribution and BNP levels > or =100 pg/mL as indicators of heart failure were assessed in 880 patients presenting with acute dyspnea to the emergency departments of five U.S. and two European teaching hospitals. BNP levels were determined by a rapid, point-of-care device. Two blinded cardiologists reviewed all clinical data and categorized patients as to whether they had acute heart failure (n = 447) or not (n = 433). RESULTS: Three-factor analyses showed that BNP levels > or =100 pg/mL contributed significantly to the prediction of heart failure over each of the radiographic indicators. In a multivariate logistic regression analysis, both BNP levels > or =100 pg/mL (odds ratio [OR] = 12.3; 95% confidence interval [CI]: 7.4 to 20.4) and radiographic findings of cardiomegaly (OR = 2.3; 95% CI: 1.4 to 3.7), cephalization (OR = 6.4; 95% CI: 3.3 to 12.5), and interstitial edema (OR = 7.0; 95% CI: 2.9 to 17.0) added significant, predictive information above historical and clinical predictors of heart failure. CONCLUSION: In patients presenting to the emergency department with acute dyspnea, BNP levels and chest radiographs provide complementary diagnostic information that may be useful in the early evaluation of heart failure.

Acute Disease↗

Impact of age, race, and sex on the ability of B-type natriuretic peptide to aid in the emergency diagnosis of heart failure: results from the Breathing Not Properly (BNP) multinational study.

BACKGROUND: B-type natriuretic peptide (BNP) is secreted from the cardiac ventricles in response to increased wall tension. METHODS: The Breathing Not Properly Multinational Study was a 7-center, prospective study of 1586 patients who presented to the Emergency Department with acute dyspnea and had BNP measured with a point-of-care assay upon arrival. The gold standard for congestive heart failure (CHF) was adjudicated by two independent cardiologists, blinded to BNP results, who reviewed all clinical data and standardized scores. The current study explores the effect of these variables on BNP decision statistics as well as the impact that changing cutoffs might have on the cost-effectiveness of diagnostic decisions that use BNP information. RESULTS: Significant differences in CHF rates were found on the basis of age (P <.001) and racial group (P =.020) but not sex (P =.424). BNP levels increased with increasing age (P <.001). To evaluate potential differences in the diagnostic utility of BNP levels as a function of demographic variables, separate receiver operating characteristic curves were performed. BNP was a stronger predictor in younger subjects than in older subjects and slightly weaker for female patients than for male patients (area under the curve = 0.918 and 0.870, respectively). An even smaller difference was noted between the white and black racial groups (area under the curve = 0.888 and 0.903, respectively). The differences in specificity as a function of age are larger than other differences in specificity or sensitivity. When logistic regression was used in a multivariate approach to combine the demographic variables with BNP information in the prediction of CHF, only BNP contributed significantly to the prediction of acute CHF. When the model was expanded to include terms for the interaction of each of the demographic variables with log(10) BNP, a significant interaction was found for sex. Since the relative consequences of false-positives and false-negatives are unlikely to be equivalent, the BNP cut-points that would be selected based on the current data as a function of relative costs are presented. Sharply rising consequences are seen for BNP cut-points >100 pg/mL. CONCLUSIONS: If one assumes that failing to treat cases of CHF is worse than treating negative cases, then relatively low BNP cut-points (eg, not >100 pg/mL) should be used in patients presenting to the Emergency Department with a chief complaint of dyspnea, regardless of age, sex, or ethnicity.

Age Distribution↗

Utility of B-natriuretic peptide in the evaluation of left ventricular diastolic function: comparison with tissue Doppler imaging recordings.

BACKGROUND: Although Doppler echocardiography provides assessment of abnormal left ventricular (LV) diastolic filling dynamics, its inherent limitations suggest the need for additional measures of diastolic dysfunction. The ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/E') derived from tissue Doppler imaging is associated with the mean LV end diastolic pressure (LVEDP). Because data suggest that B-natriuretic peptide (BNP) reflects ventricular pressure, we hypothesized that BNP levels correlate with indices of LV diastolic function by tissue Doppler imaging. METHODS AND RESULTS: Doppler recordings of the mitral inflow and tissue Doppler imaging of the mitral annulus were obtained in 108 patients referred for echocardiography. BNP levels were measured by a rapid immunoassay and blinded to cardiologists making the assessment of LV function. BNP levels were higher when elevated E/E' ratios derived from tissue Doppler imaging were identified. Patients identified with elevated LVEDP, defined as E/E' >15 (n = 16), had the highest BNP levels (463 +/- 80 pg/mL). Those with normal LVEDP, as predicted by E/E' <8 (n = 36), had a mean BNP concentration of 97 +/- 27 pg/mL. Those with E/E' of 8 to 15 (n = 48) had a mean BNP level of 122 +/- 24 pg/mL. The area under the receiver-operating curve for BNP to detect E/E' >15 was 0.89 (95% CI, 0.82 to 0.96; P < .001). A BNP value of 173 pg/mL had a sensitivity of 88%, a specificity of 82%, and an accuracy of 83% for predicting E/E' >15. CONCLUSIONS: BNP levels correlate with the E/E' ratios from tissue Doppler imaging (r = 0.48) and can reliably provide estimation of LV filling pressures. Although BNP levels do not correlate well with E/E' ratios across the full spectrum of values, the combination of BNP levels along with E/E' ratios from tissue Doppler imaging may be a better predictor of elevated LV filling pressures in patients with suspected diastolic dysfunction.

Adult↗