Finding acute coronary syndrome with serial troponin testing for rapid assessment of cardiac ischemic symptoms (FAST-TRAC): a study protocol.

OBJECTIVE: To determine the utility of a highly sensitive troponin assay when utilized in the emergency department. METHODS: The FAST-TRAC study prospectively enrolled >1,500 emergency department patients with suspected acute coronary syndrome within 6 hours of symptom onset and 2 hours of emergency department presentation. It has several unique features that are not found in the majority of studies evaluating troponin. These include a very early presenting population in whom prospective data collection of risk score parameters and the physician's clinical impression of the probability of acute coronary syndrome before any troponin data were available. Furthermore, two gold standard diagnostic definitions were determined by a pair of cardiologists reviewing two separate data sets; one that included all local troponin testing results and a second that excluded troponin testing so that diagnosis was based solely on clinical grounds. By this method, a statistically valid head-to-head comparison of contemporary and high sensitivity troponin testing is obtainable. Finally, because of a significant delay in sample processing, a unique ability to define the molecular stability of various troponin assays is possible. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00880802.

Clinical and financial impact of removing creatine kinase-MB from the routine testing menu in the emergency setting.

CONTEXT: Cardiac troponins T and I have replaced creatine kinase-MB (CK-MB) as the criterion standard for diagnosing myocardial injury. However, many laboratories still routinely perform a high volume of CK-MB testing in conjunction with troponin. PURPOSE: The purpose of this study is to study the clinical and financial impact of removing CK-MB from the routine emergency department (ED) test menu at a large academic medical center. METHODS: Creatine kinase-MB was removed from ED ordering templates and laboratory requisitions (ie, intervention), although the test could still be manually ordered. Data for creatine kinase (CK), CK-MB, and troponin T (TnT) specimens ordered during a 12-month period (6 months preintervention and 6 months postintervention) (n = 14571) was downloaded from our laboratory information system. All specimens with (1) normal TnT (ie, <0.01 ng/mL), (2) elevated CK-MB (ie, >6.6 ng/mL), and (3) elevated CK-MB index (ie, >5) were considered discrepant and independently reviewed by 2 ED clinicians for the presence of an acute coronary syndrome and for documentation of final diagnosis. Creatine kinase, CK-MB, and TnT ED volumes preintervention and postintervention were analyzed to assess laboratory cost savings. RESULTS: Of the 6444 cases included in the analysis, only 17 were discrepant. Of all 17 cases, no patients were diagnosed with acute coronary syndrome. After removing CK-MB from the templates and requisitions, CK-MB and CK volumes decreased by 80% and 76%, respectively, translating to annual reagent cost savings of approximately $47000. CONCLUSIONS: Creatine kinase-MB can be removed from the routine ED test menu without adversely affecting patient care. In addition, substantial cost savings can be achieved by reducing unnecessary CK-MB testing and associated CK orders.

Radiology utilization in the emergency department: trends of the past 2 decades.

OBJECTIVE: The objective of our study was to assess radiology utilization trends for emergency department (ED) patients from 1993 through 2012. MATERIALS AND METHODS: For this retrospective study, we reviewed radiology utilization at a 793-bed quaternary care academic medical center from January 1, 1993, through December 31, 2012, during which time the number of ED patient visits increased from approximately 48,000 to 61,000, and determined the number of imaging studies by modality (radiography, sonography, CT, MRI, other) and associated relative value units (RVUs). We used linear regression to assess for trends in the number of imaging RVUs and imaging accession numbers, our primary and secondary outcomes, respectively. RESULTS: The total RVUs attributable to ED imaging per 1000 ED visits increased 208% from 1993 to 2007 (p < 0.0001) and then decreased 24.7% by 2012 (p = 0.0019). The total number of imaging accession numbers per 1000 ED visits increased 47.8% from 1993 until 2005 (p = 0.0003) and then decreased 26.9% by 2012 (p < 0.0001). CT RVUs per 1000 ED visits increased 493% until 2007 (p < 0.0001) and then decreased 33.4% (p < 0.0001), and MRI RVUs increased 2475% until 2008 (p < 0.0001) and then decreased 20.6% (p < 0.0032). Sonography RVUs increased 75.7% over the study period (p < 0.0001), whereas radiography RVUs decreased 28.1% (p = 0.0009). CONCLUSION: After a period of substantial increase from 1993 to 2007, volume-adjusted ED imaging RVUs declined from 2007 through 2012, largely because of the decreasing use of CT and MRI. Additional studies are needed to determine the causes of this decline, which may include quality improvement activities, advocacy for appropriateness by leadership, concerns regarding radiation exposure and cost, and health information technology interventions.

Death or revascularization among nonadmitted ED patients with low-positive vs negative troponin T results.

STUDY OBJECTIVE: Compare outcomes among emergency department (ED) patients with low-positive (0.01-0.02 ng/mL) vs negative troponin T. METHODS: Retrospective cohort study of nonadmitted ED patients with troponin testing at a tertiary-care hospital. Trained research assistants used a structured tool to review charts from all nonadmitted ED patients with troponin testing, 12/1/2009 to 11/30/2010. Outcomes of death and coronary revascularization were assessed at 30 days and 6 months via medical record review, Social Security Death Index searches, and patient contact. RESULTS: There were 57596 ED visits; with 33388 (58%) discharged immediately, 6410 (11%) assigned to the observation unit, and 17798 (31%) admitted or other. Troponin was measured in 2684 (6.7%) of the nonadmitted cases. Troponin was negative in 2523 (94.0%), low positive in 78 (2.9%), and positive (≥0.03 ng/mL) in 83 (3.1%). Of troponin-negative cases, 0.8% (95% CI, 0.4-1.1%) died or were revascularized by 30 days, vs 2.8% (95% CI, 0.0-6.7%) of low-positive cases (risk difference [RD], 2.0%; 95% CI, -1.8 to 5.9%). At 6 months, the rates were 1.7% (95% CI, 1.1-2.2%) and 12.9% (95% CI, 5.0-20.7%) (RD, 11%; 95% CI, 3.3-19.1%). Death alone at 30 days occurred in 0.4% (95% CI, 0.1-0.6%) vs 1.3% (95% CI, 0.0-3.8%) (RD, 0.9%; 95% CI, -1.6 to 3.4%). Death at 6 months occurred in 1.2% (95% CI, 0.8-1.6%) vs 11.7% (95% CI, 4.5-18.9%) (RD, 10%; 95% CI, 3.3-17.7%). CONCLUSION: Among patients not initially admitted, rates of death and coronary revascularization differed insignificantly at 30 days but significantly at 6 months. Detailed inspection of our results reveals that the bulk of the added risk at 6 months was due to non-cardiac mortality.

Characteristics of adult psychiatric patients with stays of 24 hours or more in the emergency department.

OBJECTIVE: This study identified characteristics of adult psychiatric patients who remained for 24 or more hours in the emergency departments of general hospitals in Massachusetts. METHODS: Data were collected starting in June 2008 on a prospective cohort of 1,076 patients who presented for emergency psychiatric evaluation at one of five hospitals. RESULTS: A total of 90 patients (8%) stayed 24 or more hours (median=31 hours). More than 90% (N=1,018) of all patients had health insurance. Characteristics associated with extended stays included homelessness, transfer to another hospital, public insurance, and use of restraints or sitters (p<.05). The two academic medical centers had higher proportions of extended-stay patients than the three community hospitals (12% and 15% versus 1%, 7%, and 7%, respectively; p<.001). CONCLUSIONS: Despite overall high rates of health insurance coverage, publicly insured patients waited longer than those with private insurance. Future reforms of Massachusetts' mandatory health insurance program should consider treatment capacity as well.

A triage algorithm for the rapid clinical assessment and management of emergency department patients presenting with chest pain.

This article describes an algorithm for the rapid clinical assessment and evidence-based managemant of patients presenting to the Emergency Department (ED) with chest pain. While broadly applicable, it is specifically designed for use in an ED-based chest pain unit, and incorporates time-sensitive pathways for patients with acute coronary syndromes as well as observation protocols for patients in which the etiology of chest pain is less clear.

Assessment of stroke index using impedance cardiography: comparison with traditional vital signs for detection of moderate acute blood loss in healthy volunteers.

OBJECTIVES: Impedance cardiography has been used to detect early hemorrhagic shock, but, to the best of the authors' knowledge, no previous study has looked at the test characteristics of bioimpedance-derived hemodynamic parameters for the detection of a measured loss of blood volume. The authors set out to investigate the effect of controlled hemorrhage on stroke index (SI) using impedance cardiography, and to evaluate the performance of this test for moderate blood loss in comparison with the performance of traditional vital signs. METHODS: Supine and standing measurements of SI were made using a thoracic electrical bioimpedance monitor in 197 healthy, adult volunteers before and after donation of a standard unit (500 mL) of whole blood. Pre- and post-donation means for supine SI, heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP), and for the postural changes in each of these measurements ( triangle up SI, triangle up HR, triangle up SBP, triangle up DBP), were compared using a paired-sample, two-tailed t-test. For each term, receiver operating characteristic (ROC) curves were generated, treating pre- and post-donation populations as independent. Areas under the ROC curves were compared using a method for correlated test result data. RESULTS: Mean +/- SD pre- and post-donation values for SI were 47.0 +/- 6.9 mL/m(2) and 43.9 +/- 7.3 mL/m(2), respectively (p < 0.0001). Mean pre- and post-donation values for triangle up SI were -7.7 +/- 5.8 mL/m(2) and -9.0 +/- 8.2 mL/m(2), respectively (p = 0.02). For discriminating between pre- and post-donation status, the areas under the ROC curves for SI and triangle up SI were 0.62 and 0.58, respectively. In comparison, the areas under the ROC curves for HR, SBP, DBP, triangle up HR, triangle up SBP, and triangle up DBP were 0.49, 0.61, 0.56, 0.82, 0.53, and 0.50, respectively. The area under the ROC curve for triangle up HR was significantly greater than the area under any of the other curves (p < 0.0001). CONCLUSIONS: Moderate blood loss was associated with a decline in mean SI that was clearly detectable with impedance cardiography. However, as a test for moderate blood loss in this controlled setting, neither SI nor triangle up SI performed better than traditional vital signs.