Research Forum Abstracts

will allow us to test the hypothesis of high frequency of mod-severe outcomes.Methodology will include enrollment of approximately 100 patients previouslydiagnosed in an ED equivalent setting with DW at three anticoagulation clinics.These clinics also serve the patients at the applicant’s ED (110K census).Measurements include questionnaires and clinical data to assess endpoint.Additionally, we will quantitate MMPS, MCP, MPO and ICTP in banked plasmasamples. This will support the research goal of the applicant, which includes currentplans to do a research fellowship with the mentor. The project will developpreliminary data toward an intermediate goal of testing biomarkers that predict badoutcome. The ultimate goal is to proceed with therapeutic trials to reduce thisendpoint, and develop a research career.

EMF-3 Derivation and Validation of a TraumaOrgan Dysfunction Score

Vogel, MD J/Denver Health and Hospital Authority, Denver, CO

Rationale: Trauma is the most common cause of death and disability inindividuals less than 40 years old. Multiple organ dysfunction (MOD) is a leadingcause of morbidity and late mortality in trauma patients. Many scoring systems existto grade the severity of traumatic injuries and to attempt to stratify trauma patientsbased on mortality, but limited data exist to help identify patients in the emergencydepartment (ED) who will develop MOD following trauma. Existing models topredict multiple organ failure (MOF) following trauma focus on variables obtained24 to 48 hours into their hospitalizations. Research has demonstrated that MOD isfrequently already present when these models are put to use.

Hypotheses: Our first hypothesis is that patient characteristics in the out-of-hospital or ED settings may be used to derive a trauma organ dysfunction (TOD) riskscore to identify trauma patients who will develop MOD during the first seven daysfollowing hospitalization. Our second hypothesis is that the TOD risk score willcategorize patients into distinct risk strata for the prediction of MOD. The thirdhypothesis is that the TOD risk score will be internally valid, as defined by a highlevel of discrimination and calibration.

Specific Aims: The aims of this study are to: (1) use prospectively collected datafrom a high-volume urban level one trauma center to systematically derive aninstrument to predict the development of MOD using multivariable logisticregression analysis; and (2) use 10-fold cross validation to internally validate theclinical prediction instrument derived to predict MOD after trauma.

Significance: Multiple organ dysfunction is common among multiply-injuredtrauma patients and is associated with significant morbidity and mortality. Noprediction instrument currently exists to identify trauma patients at risk for MODearly in their hospital course using predictors available in the ED. The proposedresearch will provide the necessary evaluation of early organ dysfunction indicators.Early identification of trauma patients at risk for MOD may facilitate focused traumaresuscitation strategies to avert the development of organ dysfunction similar to theprovision of early goal-directed therapy in sepsis. These strategies may decrease themorbidity, mortality, and economic burden of trauma.

98 The Association Between Self-Reported Physical Fitnessand Exercise Frequency With ACS In EmergencyDepartment Chest Pain Patients

Singer A, Diercks D, Hollander JE, Thode Jr HC, Nagurney J, Peacock W/StonyBrook University, Stony Brook, NY; University of California, Davis, CA; Universityof Pennsylvania, Philadelphia, PA; Massachusetts General Hospital, Boston, MA;Cleveland Clinic, Cleveland, OH

Study Objectives: To determine the association between self-reported physicalfitness and frequency of exercising with the likelihood of acute coronary syndrome(ACS) in patients presenting to the ED with chest pain (CP). We hypothesized thatthe likelihood of ACS would be lower in physically fit patients and associated withfrequency of exercising.

Methods: Study Design-Multi center prospective descriptive, cohort. Setting-Sixacademic EDs. Subjects-ED patients with CP admitted for suspected ACS. Measuresand Outcomes-Demographic and clinical data were collected using standardizedforms. Patients were surveyed on level of fitness, and frequency of exercising. ACSwas considered present with ECG evidence of infarction or ischemia, elevatedtroponin I levels, �70% stenosis of culprit coronary artery, a positive stress test, orreadmission within 30 days for reinfarction, or cardiogenic shock. Data Analysis-Theassociation between physical fitness and exercising with ACS was determined using

chi-square tests and logistic regression analysis.

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Results: 1107 patients were enrolled. Median (IQR) age was 57 (48-67) years;506 (45.7%) were female; 737 (66.7%) % were white, 288 (26.1%) were black, 63(5.7%) were Hispanic. ACS was diagnosed in 249/1094 (22.7%). 466/1094 (42.6%)patients considered themselves low fit. Low fit patients were more likely to bediagnosed with ACS than fit patients (129/146 [27.7%] versus 120/628 [19.1%]; OR1.62 [95% CI 1.22-2.15]). After adjusting for age, sex, and prior history, low fitnesswas still associated with ACS (AOR 1.50 [95% CI 1.11-2.03]). Age, sex, and priorhistory were more predictive of ACS than fitness. There was no significant differenceamong various exercise frequency groups and prevalence of ACS (P�0.98).

Conclusion: While associated with ACS in ED patients with CP, the likelihoodof ACS in physically fit patients was still 1 in 5. Physical fitness and frequency ofexercising should not be used to exclude ACS in ED CP patients.

99 New ECG Changes In Hemorrhagic Stroke and TheirAssociation With Area of Cerebral Hemorrhage

Jain A, Manivannan V, Jain M, Bellolio M, Decker WW, Stead LG/Mayo ClinicCollege of Medicine, Rochester, MN

Study Objective: To determine if development of new ECG changes in patientswith primary non-traumatic cerebral hemorrhage (ICH) is determined by locationand volume of hemorrhage.

Methods: This study was conducted in a 75,000-visit tertiary care center ED, andwas approved by the institutional IRB. ECG changes on presentation to the ED werestudied in a cohort of ICH patients. Patients with subarachnoid, extradural, subduralor secondary hemorrhage were all excluded, as well as those who failed to sign aresearch authorization form and those under 18 years of age. ECG changes werecompared to the most recent ECG available on file for these patients. CT scans ofthese patients were also evaluated for area of hemorrhage, noting intra-ventricularextension (IVH) of hemorrhage and volume of hemorrhage itself. The volume ofhemorrhage on ECG was calculated based on ABC/2 method.

Results: 245 patients meeting inclusion criteria were identified. Of the cohort of227 ICH patients, new rhythm changes were seen in 43 patients, and new ST-Tsegment changes were noted in 46 patients.

Patients with IVH had 1.5 times the risk of developing new onset abnormalrhythms on ECGs when compared to patients without IVH (95% CI 1.1 to 2.1;p�0.0184). Patients with new rhythm changes post ICH also had higher volume ofhemorrhage (median 59.3 cc, IQR 11.5-145.9 cc) as compared to those without newrhythm abnormalities (median volume of hemorrhage 19.6 cc, IQR 3.9 - 77.1 cc;p�0.021). There was no association between rhythm abnormalities and supra/infra-tentorial location of the hemorrhage (p�0.485).

Patients with infra-tentorial hemorrhage were 1.85 times more likely to have newonset ST-T changes, when compared to those with supra-tentorial hemorrhages (95%CI 1.1 to 3.1; p�0.029). Among the supra-tentorial locations, ST-T changes weremost commonly found when the hemorrhage was located in the basal-ganglia-caudate-thalamic complex. These patients also had a higher volume of hemorrhage(median volume 47 cc, IQR 6.1-133.9 cc) as compared to those without any newST-T changes (median volume 18.7 cc, IQR 3.9-59.8 cc, p�0.042). There was noassociation between IVH and ST-T change development (p�0.908).

Conclusion: A higher volume of hemorrhage was associated with a higherlikelihood of development of both new onset rhythm and ST-T changes. Patientswith intra-ventricular extension of hemorrhage were more likely to experience rhythmabnormalities. ST-T changes were almost 1.8 times more likely to develop whenpatients had infra-tentorial hemorrhages. Location of hemorrhage and amount ofhemorrhage determines the nature of new ECG changes in patients with primaryICH.

100 Does Coronary Artery Calcium Scoring Add to thePredictive Value of Coronary CTA for AdverseCardiovascular Events In the Low Risk Chest PainPatient

Ridge NA, McCusker CM, Walsh KM, Litt HI, Hollander JE/University ofPennsylvania, Philadelphia, PA

Study objective: Coronary CT angiography (CTA) has been shown to identify agroup of ED patients with potential ACS who are safe for discharge from the EDwithout adverse events over a one-year period. It is unclear whether coronary calciumscoring enhances risk stratification of this cohort. As coronary artery calcium scoring

(CACS) is associated with additional cost and radiation burden, it should not be

Annals of Emergency Medicine S33

Research Forum Abstracts

included as a standard of care if it does not enhance the predictive value of coronaryCTA. Our hypothesis was that patients without significant coronary disease oncoronary CTA would be at low risk for one-year adverse cardiovascular events,regardless of calcium score.

Methods: We conducted a prospective cohort study at an urban universityhospital ED. Patients with symptoms suggestive of potential ACS and a low TIMIrisk score, who were unable to go home without objective testing, received CACS inconjunction with coronary CTA. Data collected in the ED included demographics,medical and cardiac history, labs, ECG and test results. The main outcome was one-year death, AMI, or revascularization in patients with coronary CTA alone versuscoronary CTA with CACS. Data were analyzed with standard descriptive techniques.

Results: 740 patients were enrolled (age 47.3 �/- 8.5; 58% females; 63% black)in the study at the time of initial ED visit and followed for one year after discharge.Overall, there were no AMI. There were no initial deaths, 1 death within 30 days(MVC), and 8 total deaths within 1 year (4 possible cardiovascular deaths). Tenpatients received a revascularization procedure: 7 during the initial hospital visit, 2patients within 30 days, and 1 patient beyond 30 days but within 1 year. Of the 656patients with a maximal coronary stenosis less than 50% visualized by CTA, therewere no AMI or revascularizations within one year, but there were 2 possiblecardiovascular deaths. Neither of these patients was identified by an elevated calciumscore (IE greater than 0).

Conclusion: In patients without significant coronary disease on coronary CTA, theaddition of a CACS does not help predict 1-year adverse cardiovascular events. Because itis associated with additional cost and radiation burden, CACS should not be a routinecomponent of coronary CTA to stratify low-risk chest pain patients in the ED.

101 QTc Prolongation and Serum ElectrolyteAbnormalities In Emergency Department Patients

House SL, Vitkovitsky I, Kim A, Treaster M, Burkett J, Halcomb SE/WashingtonUniversity in St. Louis, St. Louis, MO

Study Objectives: QTc prolongation is associated with electrolyte abnormalitiesin multiple case reports and small studies in select populations. Some recent studieshave suggested that QTc prolongation in hospitalized patients does not correlate withelectrolyte abnormalities. Very few studies, however, have investigated QTcprolongation in emergency department (ED) patients. The purpose of this study is todetermine the association of QTc prolongation in ED patients with electrolyteabnormalities.

Methods: This study was a retrospective review of ED patients who received anECG for any reason during the 3-month period of June 2009 - August 2009 at alarge volume, tertiary care center. Inclusion criteria were patients with a computergenerated QTc � 460 ms. Exclusion criteria included patients with an ECG showingbradycardia (HR � 60 bpm), tachycardia (HR � 100 bpm), QRS � 120 ms, ornon-sinus or paced rhythm. In addition, patients who left without being seen by aphysician were excluded. ED visit records were reviewed for potassium (K), calcium(Ca), and magnesium (Mg) concentrations as well as emergency physician repletionof electrolytes.

Results: 6870 patients received ECGs during this three-month period and werescreened. Of these, 1403 patients had a QTc � 460 ms (20%, 95%CI 19-21%). 766 ofthese patients were excluded due to the above criteria, leaving 637 eligible patients. Ofthese patients, 349 (55%, 95%CI 51-59%) had a QTc 460-479 ms, 162 (25%, 95%CI22-29%) had a QTc 480-499 ms, and 126 (20%, 95%CI 17-23%) had a QTc � 500ms. Serum [K] were tested in 539 patients (84%, 95%CI 82-87%), and serum [Ca] weretested in 604 patients (95%, 95%CI 93-97%). No statistically significant differences werepresent among the different QTc interval groups for physician testing of either [K] or[Ca]. Hypokalemia ([K] � 3.5 mmol/L) was observed in 98 patients (18%, 95%CI 13-19%). A statistically significant correlation between the presence of hypokalemia and QTcinterval group was observed (13% for QTc 460-479, 17% for QTc 480-499, 22% forQTc � 500, p � 0.05). Similarly, the presence of hypocalcemia ([Ca] � 8.6 mg/dL) andQTc interval group were also statistically significantly related (10% for QTc 460-479,22% for QTc 480-499, 26% for QTc � 500, p � 0.01). Both hypokalemia andhypocalcemia were repleted relatively infrequently in these patients (36% for K, 95%CI26-47% and 14% for Ca, 95%CI 7-20%) with no statistically significant differences inelectrolyte repletion among the different QTc interval groups. [Mg] was very infrequentlyobtained in these patients (17/237, 3%, 95%CI 1-4%). Mg supplementation was given toonly 12 patients (2%, 95%CI 1-3%) including only 7 patients with QTc � 500 (6%,95%CI 2-10%).

Conclusion: QTc prolongation is a common occurrence on ECGs of ED

patients. QTc prolongation is significantly associated with hypokalemia and

S34 Annals of Emergency Medicine

hypocalcemia in ED patients. The decision to replete electrolytes in the ED does notappear to be related to QTc interval prolongation. Magnesium concentration, whichis an important contributing factor to QTc prolongation, is very infrequentlyevaluated in ED patients with prolonged QTc. In addition, the prophylactictreatment of prolonged QTc with magnesium is rarely performed in ED patients.Further studies are necessary to determine the effect of electrolyte repletion andmagnesium prophylaxis in prevention of cardiac dysrhythmias in ED patients.

102 Eigenvalue Analysis as an Electrical CardiacBiomarker to Identify Acute Myocardial Infarction

Schreck DM/Summit Medical Group, Summit, NJ

Study Objectives: The cardiac electric field is considered to be largely dipolar,with very small multipolar contributions. As such, only 3 lead-vectors are needed todescribe the electrical field. Eigenvalue computer-aided mathematical modeling of the12-lead electrocardiogram (ECG) can quantify dipolar versus multipolar forcesyielding an “electrical” cardiac biomarker for the identification of acute myocardialinfarction (AMI). The objective was to test a mathematical model that quantifies themultipolar activity of the derived 12-lead ECG to identify the onset of AMI.

Methods: Digitized voltage-time ECG data arrays were retrospectively obtainedand analyzed from 47 patients with a diagnosis of AMI, and 130 patient non-AMIcontrols. Each 12-lead ECG median beat voltage-time data array was normalized andcalibrated. ECGs with missing leads, wandering baseline, excessive noise, bundlebranch blocks, and AMI ECGs greater than 1 day from initial event were excluded.Factor analysis (FA) was performed on each 12-lead ECG derived from a basis set of3 lead-vectors on the cardiac monitor to quantify the multipolar electrical field space.FA computed the eigenvalues corresponding to each of the basis 3 lead-vectors of thederived ECG that were calculated from a microcomputer-based cardiac monitoringsystem. The eigenvalue percent contribution of each basis lead-vector was comparedfor ECGs interpreted as AMI and non-AMI.

Results: The eigenvalue percent index correctly identified 44 of 47 patients withknown AMI resulting in 93.6% sensitivity. There were 126 of 130 non-AMI ECGsthat were correctly identified resulting in a 96.9% specificity. The positive predictivevalue of this method was 91.67% and the negative predictive value was 97.67%.

Conclusion: The multipolar forces of the cardiac electrical field can be quantifiedusing FA of the derived 12-lead ECG to compute an eigenvalue index that reliablydetects the presence of AMI. This “electrical” cardiac biomarker is readily computeddirectly from the patient cardiac monitor and displayed in real-time. This will allowan immediate, cost-effective, and efficient means of identifying patients with AMIwho are being monitored in acute care settings.

103 CLUE: A Comparative Effectiveness Trial ofNicardipine Versus Labetalol Use In the EmergencyDepartment

Peacock W, Baumann B, Borczuk P, Cannon C, Chandra A, Diercks D,Kaminski B, Levy P, Nowak R, Schrock J, Varon J/The Cleveland Clinic,Cleveland, OH; Cooper University Hospital, Camden, NJ; Massachusetts GeneralHospital, Boston, MA; University of Kansas, Kansas City, KS; Duke University,Durham, NC; University of California, Davis, Sacramento, CA; Toledo Hospital,Toledo, OH; Wayne State University, Detroit, MI; Henry Ford Hospital, Detroit,MI; MetroHealth Medical Center, Cleveland, OH; St. Lukes Episcopal Hospital,Houston, TX

Study Objectives: Precise blood pressure (BP) control can be critical in theemergency department. Our purpose was to compare the safety and efficacy of theFDA recommended dosing of nicardipine versus labetalol for the management ofemergency department hypertension.

Methods: Eligible patients had 2 systolic BP measures � 180 mmHg at least 10minutes apart, and no contraindications to nicardipine or labetalol. Beforerandomization, the attending emergency physician specified a target systolic BP � 20mmHg. Nicardipine dosing was 5 mg/hr, titrated q 5 minutes by 2.5 mg/hr until thetarget range was reached or max of 15 mg/hr was achieved; once in the target range,nicardipine was decreased to 3 mg/hr. Bolus labetalol began at 20 mg over 2 minutes,and was repeated at 20, 40, or 80 mg boluses q10 mins until the target range wasreached, or a max total of 300 mg. The active treatment phase was 30 minutes.

Results: CLUE enrolled 226 patients, 52.7% female, 76.4% Black, 23.1% white,with a mean age of 52.6�14.6 y, of whom 110 were treated with nicardipine and 116with labetalol. End organ damage preceded treatment in 143 (63.3%); 71 nicardipine and

72 labetalol patients. Overall mean initial systolic BP and diastolic BP was similar in each

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