Padma Krishnaswamy

B-type natriuretic peptide and clinical judgment in emergency diagnosis of heart failure: analysis from Breathing Not Properly (BNP) Multinational Study.

Background—We sought to determine the degree to which B-type natriuretic peptide (BNP) adds to clinical judgment in the diagnosis of congestive heart failure (CHF). Methods and Results—The Breathing Not Properly Multinational Study was a prospective diagnostic test evaluation study conducted in 7 centers. Of 1586 participants who presented with acute dyspnea, 1538 (97%) had clinical certainty of CHF determined by the attending physician in the emergency department. Participants underwent routine care and had BNP measured in a blinded fashion. The reference standard for CHF was adjudicated by 2 independent cardiologists, also blinded to BNP results. The final diagnosis was CHF in 722 (47%) participants. At an 80% cutoff level of certainty of CHF, clinical judgment had a sensitivity of 49% and specificity of 96%. At 100 pg/mL, BNP had a sensitivity of 90% and specificity of 73%. In determining the correct diagnosis (CHF versus no CHF), adding BNP to clinical judgment would have enhanced diagnostic accuracy from 74% to 81%. In those participants with an intermediate (21% to 79%) probability of CHF, BNP at a cutoff of 100 pg/mL correctly classified 74% of the cases. The areas under the receiver operating characteristic curve were 0.86 (95% CI 0.84 to 0.88), 0.90 (95% CI 0.88 to 0.91), and 0.93 (95% CI 0.92 to 0.94) for clinical judgment, for BNP at a cutoff of 100 pg/mL, and for the 2 in combination, respectively (P <0.0001 for all pairwise comparisons). Conclusions—The evaluation of acute dyspnea would be improved with the addition of BNP testing to clinical judgment in the emergency department.

Utility of B-Natriuretic Peptide in Detecting Diastolic Dysfunction Comparison With Doppler Velocity Recordings

Background—Although Doppler echocardiography has been used to identify abnormal left ventricular (LV) diastolic filling dynamics, inherent limitations suggest the need for additional measures of diastolic dysfunction. Because data suggest that B-natriuretic peptide (BNP) partially reflects ventricular pressure, we hypothesized that BNP levels could predict diastolic abnormalities in patients with normal systolic function. Methods and Results—We studied 294 patients referred for echocardiography to evaluate ventricular function. Patients with abnormal systolic function were excluded. Cardiologists making the assessment of LV function were blinded to BNP levels. Patients were classified as normal, impaired relaxation, pseudonormal, and restrictivelike filling patterns. Patients diagnosed with evidence of abnormal LV diastolic function (n=119) had a mean BNP concentration of 286±31 pg/mL; those in the normal LV group (n=175) had a mean BNP concentration of 33±3 pg/mL. Patients with restrictivelike filling patterns on echocardiography had the highest BNP levels (408±66 pg/mL), and patients with symptoms had higher BNP levels in all diastolic filling patterns. The area under the receiver-operating characteristic curve for BNP to detect any diastolic dysfunction was 0.92 (95% CI, 0.87 to 0.95;P <0.001). A BNP value of 62 pg/mL had a sensitivity of 85%, a specificity of 83%, and an accuracy of 84% for detecting diastolic dysfunction. Conclusions—A rapid assay for BNP can reliably detect the presence of diastolic abnormalities on echocardiography. In patients with normal systolic function, elevated BNP levels and diastolic filling abnormalities might help to reinforce the diagnosis diastolic dysfunction.

A Rapid Bedside Test for B-Type Peptide Predicts Treatment Outcomes in Patients Admitted for Decompensated Heart Failure: A Pilot Study

OBJECTIVES The goal of this study was to determine if B-type natriuretic peptide (BNP) levels predict outcomes of patients admitted with decompensated heart failure. BACKGROUND Treatment of decompensated congestive heart failure (CHF) has often been based on titration of drugs to relieve patients symptoms, a case that could be made for attempting to also treat neurohormonal abnormalities. Because BNP reflects both elevated left ventricular pressure as well as neurohormonal modulation, we hypothesized that BNP might be useful in assessing outcomes in patients admitted with decompensated CHF. METHODS We followed 72 patients admitted with decompensated New York Heart Association class III to IV CHF, measuring daily BNP levels. We then determined the association between initial BNP measurement and the predischarge or premoribund BNP measurement and subsequent adverse outcomes (death and 30-day readmission). RESULTS Of the 72 patients admitted with decompensated CHF, 22 end points occurred (death: n = 13, readmission: n = 9). In these patients, BNP levels increased during hospitalization (mean increase, 233 pg/ml, p < 0.001). In patients without end points, BNP decreased (mean decrease 215 pg/ml). Univariate analysis revealed that the last measured BNP was strongly associated with the combined end point. In patients surviving hospitalization, BNP discharge concentrations were strong predictors of subsequent readmission (area under the receiver operator curve of 0.73). CONCLUSIONS In patients admitted with decompensated CHF, changes in BNP levels during treatment are strong predictors for mortality and early readmission. The results suggest that BNP levels might be used successfully to guide treatment of patients admitted for decompensated CHF.

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 Conclusions Rapid testing of BNP in the ED should help differentiate pulmonary from cardiac etiologies of dyspnea.

Utility of B-Natriuretic Peptide in Detecting Diastolic Dysfunction

Background— Although Doppler echocardiography has been used to identify abnormal left ventricular (LV) diastolic filling dynamics, inherent limitations suggest the need for additional measures of diastolic dysfunction. Because data suggest that B-natriuretic peptide (BNP) partially reflects ventricular pressure, we hypothesized that BNP levels could predict diastolic abnormalities in patients with normal systolic function. Methods and Results— We studied 294 patients referred for echocardiography to evaluate ventricular function. Patients with abnormal systolic function were excluded. Cardiologists making the assessment of LV function were blinded to BNP levels. Patients were classified as normal, impaired relaxation, pseudonormal, and restrictivelike filling patterns. Patients diagnosed with evidence of abnormal LV diastolic function (n=119) had a mean BNP concentration of 286±31 pg/mL; those in the normal LV group (n=175) had a mean BNP concentration of 33±3 pg/mL. Patients with restrictivelike filling ...

Utility of B-natriuretic peptide levels in identifying patients with left ventricular systolic or diastolic dysfunction

Abstract Purpose Although echocardiography is important for making the diagnosis of left ventricular dysfunction, its cost and lack of availability limit its use as a routine screening test. B-Natriuretic peptide levels accurately reflect ventricular pressure, and preliminary studies with a rapid assay have found that levels are sensitive and specific for diagnosing heart failure in patients with dyspnea. We hypothesized that B-natriuretic peptide levels obtained through the use of a rapid assay should correlate with echocardiographic abnormalities of ventricular function. Subjects and methods We studied 400 patients who were referred for echocardiography at the San Diego Veterans Healthcare System between June and August 2000 to evaluate ventricular function. B-natriuretic peptide levels were measured by a point-of-care immunoassay; cardiologists assessing left ventricular function were blinded to the assay results. Patients were grouped into those with normal ventricular function, systolic dysfunction only, diastolic dysfunction only, and both systolic and diastolic dysfunction. Results Mean (± SD) B-natriuretic peptide concentration was 416 ± 413 pg/mL in the 253 patients diagnosed with abnormal left ventricular function, compared with 30 ± 36 pg/mL in the 147 patients with normal left ventricular function. Patients with both systolic and diastolic dysfunction had the highest levels (675 ± 423 pg/mL). The area under the receiver operating characteristic (ROC) curve for B-natriuretic peptide levels to detect any abnormal echocardiographic finding was 0.95 (91% confidence interval: 0.93 to 0.97). B-Natriuretic peptide levels were unable to differentiate systolic vs. diastolic dysfunction. In patients with symptoms of heart failure and normal systolic function, B-natriuretic peptide levels >57 pg/mL had a positive predictive value of 100% for diastolic abnormalities. Conclusions A simple, rapid test for B-natriuretic peptide levels can reliably predict the presence or absence of left ventricular dysfunction on echocardiogram. For some patients, a normal level may preclude the need for echocardiography.

Bedside B-Type natriuretic peptide in the emergency diagnosis of heart failure with reduced or preserved ejection fraction

OBJECTIVES This study examines B-type natriuretic peptide (BNP) levels in patients with systolic versus non-systolic dysfunction presenting with shortness of breath. BACKGROUND Preserved systolic function is increasingly common in patients presenting with symptoms of congestive heart failure (CHF) but is still difficult to diagnose. METHODS The Breathing Not Properly Multinational Study was a seven-center, prospective study of 1,586 patients who presented with acute dyspnea and had BNP measured upon arrival. A subset of 452 patients with a final adjudicated diagnosis of CHF who underwent echocardiography within 30 days of their visit to the emergency department (ED) were evaluated. An ejection fraction of greater than 45% was defined as non-systolic CHF. RESULTS Of the 452 patients with a final diagnosis of CHF, 165 (36.5%) had preserved left ventricular function on echocardiography, whereas 287 (63.5%) had systolic dysfunction. Patients with non-systolic heart failure (NS-CHF) had significantly lower BNP levels than those with systolic heart failure (S-CHF) (413 pg/ml vs. 821 pg/ml, p < 0.001). As the severity of heart failure worsened by New York Heart Association class, the percentage of S-CHF increased, whereas the percentage of NS-CHF decreased. When patients with NS-CHF were compared with patients without CHF (n = 770), a BNP value of 100 pg/ml had a sensitivity of 86%, a negative predictive value of 96%, and an accuracy of 75% for detecting abnormal diastolic dysfunction. Using Logistic regression to differentiate S-CHF from NS-CHF, BNP entered first as the strongest predictor followed by oxygen saturation, history of myocardial infarction, and heart rate. CONCLUSIONS We conclude that NS-CHF is common in the setting of the ED and that differentiating NS-CHF from S-CHF is difficult in this setting using traditional parameters. Whereas BNP add modest discriminatory value in differentiating NS-CHF from S-CHF, its major role is still the separation of patients with CHF from those without CHF.

Ninety-minute accelerated critical pathway for chest pain evaluation

Rapid, efficient, and accurate evaluation of chest pain patients in the emergency department optimizes patient care from public health, economic, and liability perspectives. To evaluate the performance of an accelerated critical pathway for patients with suspected coronary ischemia that utilizes clinical history, electrocardiographic findings, and triple cardiac marker testing (cardiac troponin I [cTnI], myoglobin, and creatine kinase-MB [CK-MB]), we performed an observational study of a chest pain critical pathway in the setting of a large Emergency Department at the Veterans Affairs Medical Center in 1,285 consecutive patients with signs and symptoms of cardiac ischemia. The accelerated critical pathway for chest pain evaluation was analyzed for: (1) accuracy in triaging of patients within 90 minutes of presentation, (2) sensitivity, specificity, positive predictive value, and negative predictive value of cTnI, myoglobin, and CK-MB in diagnosing acute myocardial infarction (MI) within 90 minutes, and (3) impact on Coronary Care Unit (CCU) admissions. All MIs were diagnosed within 90 minutes of presentation (sensitivity 100%, specificity 94%, positive predictive value 47%, negative predictive value 100%). CCU admissions decreased by 40%. Ninety percent of patients with negative cardiac markers and a negative electrocardiogram at 90 minutes were discharged home with 1 patient returning with an MI (0.2%) within the next 30 days. Thus, a simple, inexpensive, yet aggressive critical pathway that utilizes high-risk features from clinical history, electrocardiographic changes, and rapid point-of-care testing of 3 cardiac markers allows for accurate triaging of chest pain patients within 90 minutes of presenting to the emergency department.

Mitigation of the clinical significance of spurious elevations of cardiac troponin I in settings of coronary ischemia using serial testing of multiple cardiac markers.

The ability to differentiate between true positives, false positives, and sporadically elevated cardiac troponin levels has grown in importance as cardiac troponins assume an increasingly dominant role in the diagnosis of coronary syndromes. In a population sample of 1,000 patients who presented consecutively to a large urban hospital emergency room, 50 of 112 patients who had elevated troponin levels (> 0.6 ng/ml) during evaluation for myocardial injury were subsequently found to have had an isolated, spurious elevation of cardiac troponin, and not a diagnosed myocardial infarction. Logistic regression analysis shows that by hierarchically analyzing electrocardiographic changes with concurrent creating kinase-MB and myoglobin levels at the time of the troponin elevation, one may predict with 91% accuracy whether the troponin elevation is actually indicative of a myocardial infarction in a patient. Spurious troponin elevations may be a common occurrence, and if not detected, may result in an increased number of falsely diagnosed myocardial infarctions.

A rapid bedside test for B-type natriuretic peptide predicts treatment outcomes in patients admitted with decompensated heart failure

readmission). Results: Of the 72 patients admitted with decompensated CHF, 22 endpoints occurred (death n = 12, readmission: n = 10). In patients without end-points, BNP decreased during treatment ((-)448 pg/ml). In patients who died or were later readmitted, BNP levels increased during hospitalization ((+)590 pg/ml, P < 0.001). despite improvement in NYHA classification. Multivariate analysis revealed discharge BNP to be highly predictive of endpoints. ROC analysis revealed 2 cut-points, a discharge BNP of 21220 pg/ml which had an odds-ratio 25.1 for endpoints and a positive predictive value of 75%, and discharge BNP level 5 430 pg/ml which had a negative predictive value of 96 percent for endpoints. Conclusions: In patients admitted with decompensated CHF, changes in BNP levels during treatment are strong predictors for mortality and early readmission. The results of this study further suggest that therapy for decompensated heart failure should be tailored to decreasing the BNP level during hospitalization.