Search

Objectives: The objective was to determine the incremental benefit of a shortness-of-breath (SOB) point-of-care biomarker panel on the diagnostic accuracy of emergency department (ED) patients presenting with dyspnea. Methods: Adult ED patients at 10 U.S. EDs with SOB were included. The physician’s estimates of the pretest clinical probability of heart failure (HF), acute myocardial infarction (MI), and pulmonary embolism (PE) were recorded using deciles (0%–100%). Blood samples were analyzed using a SOB point-of-care biomarker panel (troponin I, myoglobin, creatinine kinase-myocardial band isoenzyme [CK-MB], D-dimer, and B-type natriuretic peptide [BNP]). Thirty-day follow-up for MI, HF, and PE was performed. Data were analyzed using logistic regression and receiver operating characteristics (ROC) curve analysis. Results: Of 301 patients, the mean (±standard deviation [SD]) age was 61 (±18) years; 56% were female, 58% were white, and 38% were African American. Diagnoses included MI (n = 54), HF (n = 91), and PE (n = 16) in a total of 129 (43%) of the patients. High pretest clinical certainty (≥80%) identified 60 of these 129 (46.5%) cases. The SOB point-of-care biomarker panel identified 66 additional cases of MI (n = 24), HF (n = 31), and PE (n = 11). The overall adjusted sensitivity for any diagnosis was increased from 65% to 70% with the addition of the SOB point-of-care biomarker panel (difference = 5%, 95% CI = −1.1% to 11%) while specificity was increased from 82% to 83% (difference = 1%, 95% CI = −4% to 7%). The model containing pretest probability and the results of the SOB panel had an area under the curve (AUC) of 83.4% (95% CI = 78.4% to 88.5%), which was not significantly better than the AUC of 80.4% (95% CI = 75.1% to 85.7%) for clinical probability alone. Conclusions: The addition of the SOB panel of markers did not improve the AUC for diagnosing the combined set of clinical conditions. Using the disease-specific SOB biomarkers increased the sensitivity on a disease-by-disease basis; however, specificity was reduced.

Background Cardiac troponin T (cTnT), high sensitivity C-reactive protein (hs-CRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) have emerged as strong predictors of adverse events among patients presenting with acute coronary syndromes (ACS). We evaluated the prognostic performance of each of these markers, individually, and in combination in patients presenting to the emergency department (ED) with ACS symptoms. Methods Serum samples were obtained from 422 consenting patients presenting to the ED with symptoms of acute coronary syndrome (ACS) and subsequently tested for cTnT, NT-proBNP, myoglobin, CK-MB, and hs-CRP. Adverse events (AEs) occurring within 30 days (death, myocardial infarction, unstable angina and the need for revascularization procedures) were recorded and ROC curves were constructed. Results AEs occurred in 42 patients (10%). Relative risk, cut-off, and predictive values for each biomarker were determined statistically, with the exception of cTnT, where the concentration meeting the 99th percentile of a healthy population with a 10% coefficient of variation (0.03 ng/ml) was used. These cut-off values, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and relative risk (RR) were calculated. Sensitivity and RR for a panel of cTnT and NT-proBNP were 78.6% (66.2–91.0) and 4.7 (2.3–9.5), respectively. Conclusions If used alone, cTnT appeared to have greater prognostic value when compared to hs-CRP, NT-proBNP, myoglobin or CK-MB. The combination of cTnT and NT-proBNP performed better than the combination of cTnT and hs-CRP. When cTnT, NT-proBNP and hs-CRP were used as a panel, there was no significant improvement in prognostic performance over using cTnT and NT-proBNP together. Thus, in patients with suspected ACS, the measurement of both cTnT and NT-proBNP may have enhanced prognostic performance over using either marker in isolation.

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.

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.

The relationship between BNP and NT-proBNP among physiologically and clinically relevant demographic subgroups has never been clarified in the context of the emergency department (ED).A blood sample taken from patients presenting to the E.D. with suspected acute coronary syndromes (ACS) was analyzed for BNP and NT-proBNP, and correlation between them was examined as an entire group then as subgroups according to gender, ethnicity, age, and comorbidity variables.BNP and NT-proBNP correlate well (0.89, P0.0001) in a population of 420 patients and in patient subgroups with a history of various etiologies, including vascular disorders.In general, BNP and NT-proBNP correlate very well in patients with suspected ACS and may aid in the risk stratification process in emergency departments.

The potential clinical utility of single sample CK-MB isoforms measurement for early risk stratification of Emergency Department (ED) patients with possible myocardial ischemia was evaluated among 405 patients presenting to two urban EDs. Clinical and serologic data were prospectively collected and the occurrence of adverse events (AEs) and myocardial infarction (MI) during the 14-day outcome period was recorded and utilized to calculate and compare relative risks (RR) and predictive values of isoforms and CK-MB alone. Among the 405 patients, 67 accrued 105 AEs. Both isoforms and CK-MB alone were predictive of AEs with RR of 3.32 (2.09, 5.27) and 6.28 (4.64, 8.52), respectively. Isoforms had higher sensitivity for AEs compared to CK-MB (65.7% [54.3, 77.0] vs. 14.9% [6.4, 23.5]; p0. 01) but lower specificity (69.2% [64.3, 74.2] vs. 99.7% [99.1,100. 0]; p0.01). Isoforms' superior sensitivity allowed identification of many high risk patients missed by CK-MB alone. Further, for the prediction of MI, isoforms had superior diagnostic sensitivity and equivalent specificity. This investigation supports the emergency department use of early, single sample CK-MB isoform testing.

Objectives: To determine and compare the prognostic abilities of early, single-sample myoglobin measurement with that of creatine kinase-MB (CK-MB), with cardiac troponin T (cTnT), and with physician judgment in the absence of marker results among emergency department (ED) patients with possible myocardial ischemia. Methods: Prospective collection of clinical and serologic data using an identity-unlinked technique from patients with possible myocardial ischemia at two urban EDs. Outcome data concerning the occurrence of adverse events (AEs) during the 14 days after enrollment were used to calculate and compare the relative risks (RRs) and predictive values (with 95% confidence intervals) of the various markers for predicting AEs. Results: Among 396 analyzed patients, 65 (16.4%) accrued 104 AEs, including 13 deaths (3.3%) and 31 (7.8%) myocardial infarctions. Myoglobin predicted AEs (RR = 3.36 [95% CI = 2.19 to 5.15]) with significantly higher sensitivity (50.8% [95% CI = 38.6 to 62.9]) than either CK-MB (15.4% [95% CI = 6.6 to 24.2]) or cTnT (24.6% [95% CI = 14.1 to 35.1]), but with lower specificity (81.9% [95% CI = 77.7 to 86.0]; CK-MB = 99.7% [95% CI = 99.1 to 100]; cTnT = 93.1% [95% CI = 90.3 to 95.8]). Myoglobin had prognostic ability among patients with chest pain (3.86 [95% CI = 2.39 to 6.22]) and atypical (non-chest pain) presentations (2.71 [95% CI = 1.09 to 6.71]), including those with a non-diagnostic electrocardiogram (3.11 [95% CI = 1.44 to 6.69]). The combination of myoglobin and physician decision making identified 63 of the 65 patients (96.9% [95% CI = 92.7 to 100]) with subsequent AEs. Conclusions: The early prognostic sensitivity of myoglobin may allow identification of some high-risk patients missed by physician judgment, CK-MB, and cTnT. Myoglobin should be considered for use in the ED based on both its diagnostic and prognostic abilities.

It has long been known that among patients with end-stage renal disease (ESRD), cardiac disease is the single greatest cause of mortality, accounting for nearly one half of all deaths (1). Among community-based populations, renal insufficiency is an independent predictor of the risk of subsequent ischemic heart disease, conferring a risk equivalent to that of diabetes (2). Furthermore, the presence of even moderate renal impairment in a patient presenting with an acute coronary syndrome (ACS) is a strong short-term prognostic indicator, significantly increasing the 30-day risk of myocardial infarction, heart failure, and cardiac death (3). Thus, a strong and pervasive link clearly exists between kidney failure and cardiac disease. The common challenge to the nephrologist, cardiologist, and emergency physician therefore lies in successfully recognizing those patients within their scope of practice who are most at risk, thereby allowing targeted application of interventions designed to circumvent adverse outcomes. Accordingly, there is an exigent need for the clinical laboratory to identify and make available reliable assays for biomarkers that can predict adverse events across a range of clinical settings and among patients with various degrees of kidney dysfunction, as well as to elucidate the performance characteristics and limitations of each of these markers. A variety of individual biomarkers have previously been evaluated for this purpose, and several have been found to successfully predict outcome in patients with kidney disease. These include markers of myocardial necrosis, such as cardiac troponin T (cTnT) and I (cTnI) (4); markers of heart failure, such as B-type natriuretic peptide (BNP) and its associated inactive N-terminal fragment (NT-proBNP) (5); and the marker of systemic inflammation, high-sensitivity C-reactive protein (hsCRP) (6). However, fulfillment of the obvious potential of these biomarkers to have a positive impact on the care of renal failure patients has been elusive because of unresolved clinical …

Study objective: Chest pain and myocardial infarction following the use of cocaine have been well documented. We assessed the prevalence of cocaine use in patients who presented to the emergency department with chest pain of possibly ischemic origin. Design: During times of research assistant availability, consecutive adults with the chief complaint of chest pain unexplained by trauma or radiographic abnormality were questioned about cocaine use in the preceding week. Urine was tested for the presence of cocaine or cocaine metabolites with a highly accurate bedside urine test kit (specificity, 100%; sensitivity 98%). Anonymous unlinked data-collection methods were used. Therefore we could not determine whether the patients who used cocaine had sustained myocardial infarctions. Setting: One suburban and three urban EDs. Results: We enrolled 359 patients with a mean age of 51 years, 8% of whom sustained myocardial infarctions. Sixty patients (17%) had cocaine or cocaine metabolites in urine. The likelihood of testing positive for cocaine varied by age group: 18 to 30 years, 29%; 31 to 40 years, 48%; 41 to 50 years, 18%; 51 to 60 years, 3%; 61 years or older, 0% ( P Conclusion: Many ED patients with chest pain have recently used cocaine. Because the recent use of cocaine is not uncommon in patients with chest pain up to 60 years old, such patients should be questioned about cocaine use. When treatment or disposition may be altered, consideration should be given to objective assessment of cocaine use because patient self-report does not appear reliable. [Hollander JE, Todd KH, Green G, Heilpern KL, Karras DJ, Singer AJ, Brogan GX, Funk JP, Strahan JB: Chest pain associated with cocaine: An assessment of prevalence in suburban and urban emergency departments. Ann Emerg Med December 1995;26:671-676.]

In order to determine the sensitivity and specificity of two rapid human immunodeficiency virus (HIV-1) assays compared with enzyme immunoassay and Western blot and to assess their potential use for routine screening in an emergency department (ED), we analyzed sera from 492 consecutive ED patients using an identity-unlinked design. Sera were analyzed for HIV-1 by standard enzyme-linked immunosorbent assay and Western blot and two rapid assays: the Abbott Testpack HIV-1 (Abbott Labs, Inc, Abbott Park, IL) and the HIV-1 Genie, (Genetic Systems, Seattle, WA). Seroprevalence of HIV-1 among 492 samples was 5.1%. Both rapid assays were easy to perform and required approximately 10 minutes per test. Sensitivity and specificity of both rapid assays were 100% and 99.8%, with positive and negative predictive values of 96.2% and 100%, respectively. It was concluded that both rapid assays showed high concordance with standard enzyme-linked immunosorbent assay and Western blot. Since the ED is often the primary care setting for many patients at risk for HIV-1, the ED may be an optimal site for routine HIV-1 screening. Rapid assay screening may provide the opportunity for timely identification of HIV-1-infected patients, allowing earlier treatment and counseling. However, ethical and practical questions regarding appropriate application of rapid HIV-1 testing in EDs still needs resolution.

Background: Higher circulating concentrations of pregnancy-associated plasma protein A (PAPP-A), a potential proatherosclerotic metalloproteinase, have been associated with increased risk for acute coronary syndrome (ACS). Our goal was to determine the ability of circulating concentrations of PAPP-A to predict adverse events in patients presenting to the Emergency Department (ED) with symptoms of ACS. Methods: A total of 346 patients with symptoms of ACS were included in the study. Serum samples obtained immediately after enrollment were analyzed for PAPP-A and cardiac troponin T (cTnT). The occurrence of adverse events during a 30-day follow-up period was recorded, and receiver-operating characteristic (ROC) curve analysis was performed to evaluate the prognostic characteristics of PAPP-A and cTnT. Results: A total of 33 (9.5 %) patients developed adverse events during the follow up period. At a cut-off concentration of 0.22 mIU/l, PAPP-A was a predictor of adverse events with a sensitivity and specificity (95% C.I.) of 66.7% (48.2–82.0) and 51.1% (45.4–56.8), respectively. The sensitivity and specificity of cTnT were 51.5% (33.6–69.2) and 82.1% (77.4–86.2), respectively, using a 0.01-ng/ml cut-off value, which was obtained using ROC analysis. Conclusions: PAPP-A appears to be a modest predictor of adverse events in patients presenting to the ED with ACS symptoms, being inferior to cTnT in predicting adverse events in an ED setting. PAPP-A appears to be as sensitive as cTnT, but it is less specific.

OBJECTIVES: To determine and compare the prognostic abilities of early, single-sample measurements of cardiac troponin I (cTn-I), cardiac troponin T (cTn-T), and creatine kinase-MB (CK-MB) among ED patients with possible myocardial ischemia. METHODS: Prospective collection of clinical and serologic data using an identity-unlinked technique from patients with possible myocardial ischemia at 2 urban EDs. Outcome data concerning the occurrence of adverse events (AEs) during the 14 days after enrollment were used to calculate and compare the relative risks (RRs) and predictive values (with 95% confidence intervals) of the 3 markers for predicting AEs. RESULTS: Among the 401 study patients, 105 AEs occurred in 67 patients. cTn-I, cTn-T, and CK-MB were all significantly predictive of AEs, with RRs of 3.87 (2.39, 6.26), 3.03 (1.92, 4.79), and 6.45 (4.74, 8.77), respectively. For prediction of AEs, sensitivity for each of the 3 markers was low (cTn-I = 15.38, cTn-T = 24.62, CK-MB = 15.38), while specificity was high (cTn-I = 97.62, cTn-T = 93.15, CK-MB = 99.70). No significant difference in predictive ability was found between cTn-I and cTn-T. However, a positive CK-MB result was a stronger predictor of AEs than either cTn-I (p = 0.01) or cTn-T (p = 0.001). CONCLUSIONS: No significant difference in predictive abilities was found between cTn-I and cTn-T. However, routine testing for both CK-MB and either of the troponins may optimize early identification of high-risk patients so they may be targeted for a higher level of care and consideration of more aggressive therapies.

Study Objectives: To evaluate and compare the utility of measurement of troponin T and the creatine kinase MB subunit (CK-MB) for risk stratification of ED patients with possible myocardial ischemia. Methods: Prospective observational study of ED patients with symptoms of possible myocardial ischemia with early, single sample serologic testing for cardiac troponin T and CK-MB using an identity-unlinked process. Chart review (ED, inpatient, outpatient), and telephone and mail surveys identified adverse events (AEs) during the 14 days following enrollment. AEs recorded included death, respiratory or cardiac arrest, myocardial infarction (MI), atrial and ventricular arrhythmias, pulmonary edema, conduction disturbances, and recurrent angina. Measures of the predictive ability for AEs were calculated for troponin T, CK-MB, and a combined troponin T/CK-MB index (defined as positive if either troponin T or CK-MB levels exceeded threshold values). Results: Among 292 study patients, 45 (15.4%) experienced at least one AE, including seven deaths and 12 MIs. The troponin T result was positive in 34 patients, and the CK-MB result was positive in 15 patients; 6 patients had positive results for both markers and 43 patients had a positive combined troponin T/CK-MB index. Odds ratios (ORs) for occurrence of AEs among all patients were 4.4 (1.8 to 10.2), 10.0 (3.0 to 36.0), and 4.5 (2.0 to 9.8) for troponin T, CK-MB, and the troponin T/CK-MB index, respectively. Both markers were individually predictive of AEs (troponin T=4.3; CK-MB=7.5) among all those with chest pain. Only the CK-MB level was significantly predictive of AEs among those presenting with symptoms other than chest pain (OR=24.3 [1.1, 1448]), whereas only the troponin T level was significantly predictive among patients representing a disposition dilemma for the emergency physician (OR=5.7 [1.4, 20.7]). When compared, the ORs for troponin T and CK-MB were not significantly different for any patient subgroup. The troponin T/CK-MB index did not have a higher prognostic value than either troponin T or CK-MB alone in any subgroup studied. Conclusion: A positive test result for either troponin T or CK-MB in the ED successfully identified patients at significantly higher risk of adverse events during the 2 weeks following their ED visit. The two markers may complement each other in that each appears to have prognostic ability among a unique patient subgroup. ED marker measurement can provide useful prognostic information for patients with a broad spectrum of presentations consistent with possible myocardial ischemia. [Green GB, Beaudreau RW, Chan DW, DeLong D, Kelley CA, Kelen GD: Use of troponin T and creatine kinase-MB subunit levels for risk stratification of emergency department patients with possible myocardial ischemia. Ann Emerg Med January 1998;31:19-29.]

Atherosclerotic vascular disease has been present in humans for thousands of years. Atherosclerotic lesions were identified in Egyptian mummies dating as early as the 15th century B.c. In the 19th century, researchers speculated that arterial wall injury may cause an inflammatory response, resulting in atherosclerotic lesions (1). By the early 1900s investigators had proposed a correlation among the degree of atheroscle-rotic lesions, acute myocardial infarction (AMI)*, and stroke (2). The prevention and treatment of coronary artery atherogenesis is a major public health concern today (3).

Infections with hepatitis B virus (HBV), hepatitis C virus (HCV), and the human immunodeficiency virus type 1 (HIV-1) are common in inner-city populations, but their frequency and interrelations are not well established.During a six-week period, excess serum samples were collected, along with information on risk factors, from all adult patients presenting to an inner-city emergency department. The samples were assayed for hepatitis B surface antigen (HBsAg) and antibodies to HCV and HIV-1.Of the 2523 patients tested, 612 (24 percent) were infected with at least one of the three viruses. Five percent were seropositive for HBV, 18 percent for HCV, and 6 percent for HIV-1. HCV was found in 145 of the 175 intravenous drug users (83 percent), 36 of the 171 transfusion recipients (21 percent), and 5 of the 24 homosexual men (21 percent). Among black men 35 to 44 years of age, the seroprevalence of HCV was 51 percent. HBsAg was present in 9 percent of those whose only identifiable risk was possible heterosexual exposure. At least one viral marker was found in about 30 percent of the patients who were actively bleeding or in whom procedures were performed. Testing for HIV-1 alone would have failed to identify 87 percent of the patients infected with HBV and 80 percent of those infected with HCV.In a population of patients in an inner-city emergency room, HBV, HCV, and HIV-1 are all highly prevalent. However, routine screening for HIV-1 alone would identify only a small fraction of the patients who pose risks of severe viral infections, including HBV and HCV, to providers.

Study objectives: To determine the sensitivity, specificity, and predictive values of a new rapid creatine kinase-MB (R-CK-MB) assay compared with a standard CK-MB (S-CK-MB) assay and to determine its potential use in the evaluation of emergency department patients with possible myocardial infarction. Design: Retrospective patient identification with subsequent testing of excess sera for CK-MB and total CK using an identity-unlinked procedure. Setting: Large, urban, teaching hospital ED. Participants: All adult patients with excess sera and one of several defined presentations chosen to identify those with possible myocardial ischemia or infarction. Patients with clearly documented noncardiac etiologies of their symptoms or signs were excluded. Main results: The sensitivity, specificity, and positive and negative predictive values of 271 patient specimens for the R-CK-MB assay compared with the S-CK-MB assay were 100%, 96.8%, 75.0%, and 100%, respectively. The R-CK-MB assay was positive for 32 patients (11.8%). Of these, eight (25.0%) were admitted to unmonitored beds, and five (15.6%) were discharged home. All of these 13 patients had initial ECGs without evidence of ischemia or infarction. On follow-up, at least eight of the 13 had evidence of infarction. Conclusion: The R-CK-MB assay demonstrated high sensitivity and specificity compared with the S-CK-MB assay. When used for patients in whom a cardiac care unit admission is not considered, the rapid assay may identify some patients with unsuspected myocardial infarction and prevent inadvertent discharge or admission to unmonitored beds.

Seven months following the introduction of an institutional policy mandating compliance with universal precautions (UPs), we observed 127 health care workers performing 1421 interventions on 155 critically ill and injured patients in an emergency department setting in July 1989. Results were compared with a similar study undertaken exactly 1 year previously when UPs were considered as guidelines only. Overall adherence to UPs improved from 44.0% to 72.7% from 1 year to the next. Adherence to UPs improved from 19.5% to 55.7% during interventions on patients with profuse bleeding and from 16.7% to 54.5% during performance of major procedures. Compliance improved from 47.9% to 81.0% for emergency departmentbased health care workers (residents, attending physicians, nurses, x-ray film technicians). Prehospital care providers, a group not accountable to the institution, remained particularly noncompliant with only 13% adherence. We conclude that mandating UPs as policy with a monitoring component is effective in ensuring a reasonable level of adherence. However, given current barrier technology, achieving appropriate levels of compliance during unscheduled visits by patients requiring immediate attention and rapid intervention remains a challenge. ( Arch Intern Med. 1991;151:2051-2056)