Browsing by Author "Drake, Weiying"

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    Are patients with longer emergency department wait times less likely to consent to research?
    (Acad Emerg Med, 2012-04) Limkakeng, Alexander T; Glickman, Seth W; Shofer, Frances; Mani, Giselle; Drake, Weiying; Freeman, Debbie; Ascher, Simon; Pietrobon, Ricardo; Cairns, Charles B
    OBJECTIVES: There are unique challenges to enrolling patients in emergency department (ED) clinical research studies, including the time-sensitive nature of emergency conditions, the acute care environment, and the lack of an established relationship with patients. Prolonged ED wait times have been associated with a variety of adverse effects on patient care. The objective of this study was to assess the effect of ED wait times on patient participation in ED clinical research. The hypothesis was that increased ED wait times would be associated with reduced ED clinical research consent rates. METHODS: This was a retrospective cohort study of all patients eligible for two diagnostic clinical research studies from January 1, 2008, through December 31, 2008, in an urban academic ED. Sex, age, race, study eligibility, and research consent decisions were recorded by trained study personnel. The wait times to registration and to be seen by a physician were obtained from administrative databases and compared between consenters and nonconsenters. An analysis of association between patient wait times for the outcome of consent to participate was performed using a multivariate logistic regression model. RESULTS: A total of 903 patients were eligible for enrollment and were asked for consent. Overall, 589 eligible patients (65%) gave consent to research participation. The consent rates did not change when patients were stratified by the highest and lowest quartile wait times for both time from arrival to registration (68% vs. 65%, p = 0.35) and time to be seen by a physician (65% vs. 66%, p = 0.58). After adjusting for patient demographics (age, race, and sex) and study, there was still no relationship between wait times and consent (p > 0.4 for both wait times). Furthermore, median time from arrival to registration did not differ between those who consented to participate (15 minutes; interquartile range [IQR] = 9 to 36 minutes) versus those who did not (15.5 minutes; IQR = 10 to 39 minutes; p = 0.80; odds ratio [OR] = 1.00, 95% confidence interval [CI] = 0.99 to 1.01). Similarly, there was no difference in the median time to be seen by a physician between those who consented (25 minutes; IQR = 15 to 55 minutes) versus those who did not (25 minutes; IQR = 15 to 56 minutes; p = 0.70; OR = 1.00, 95% CI = 0.99 to 1.01). CONCLUSIONS: Regardless of wait times, nearly two-thirds of eligible patients were willing to consent to diagnostic research studies in the ED. These findings suggest that effective enrollment in clinical research is possible in the ED, despite challenges with prolonged wait times.
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    Evaluation of T-Wave Morphology in Patients With Left Bundle Branch Block and Suspected Acute Coronary Syndrome.
    (The Journal of emergency medicine, 2016-09) Meyers, H Pendell; Jaffa, Elias; Smith, Stephen W; Drake, Weiying; Limkakeng, Alexander T
    T-wave morphology in the setting of left bundle branch block (LBBB) has been proposed as an indicator of myocardial ischemia.We sought to identify T-wave morphology findings in patients with LBBB that predict non-ST-segment elevation myocardial infarction (NSTEMI). We hypothesized that two or more contiguous leads with concordant T waves would be predictive of NSTEMI.This was a retrospective cohort study performed by chart review in a tertiary care center emergency department. We identified a consecutive cohort who presented with LBBB and symptoms consistent with acute coronary syndrome. Exclusion criteria were diastolic blood pressure > 120 mm Hg, heart rate > 130 beats/min, positive pressure ventilation, potassium > 5.5 mEq/L, and cardiac arrest without prearrest electrocardiogram (ECG) available. We collected ECGs and classified T waves into five categories based on morphology, blinded to clinical outcome. Clinical outcome data were collected blinded to ECG findings. Those with ECG diagnostic of STEMI by modified Sgarbossa criteria were excluded from the primary analysis, which was sensitivity and specificity of two or more contiguous leads with concordant T waves for NSTEMI.There were 246 patients included. Mean age was 73 years; 160 (65%) were female, and 32 had myocardial infarction. Thirty percent had two or more contiguous precordial leads with partially or completely concordant T waves. For NSTEMI, the sensitivity and specificity of this finding were 19% (95% confidence interval [CI] 8-37) and 68% (95% CI 61-74).We found no clinically useful relationship between T-wave concordance and myocardial infarction in our patient population. Future investigation of LBBB T-wave morphology should focus on alternative populations and findings.
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    Left ventricular dysfunction screening in hypertensive patients with N-terminal pro-B-type natriuretic peptide and electrocardiogram.
    (Am J Emerg Med, 2012-01) Limkakeng, Alexander T; Drake, Weiying; Mani, Giselle; Freeman, Debbie; Best, Randall; Newby, L Kristin; Chandra, Abhinav
    OBJECTIVE: Early recognition of left ventricular hypertrophy is important because antihypertensive treatment decreases morbidity and mortality. The ideal screening method for left ventricular hypertrophy in hypertensive emergency department (ED) patients has not been identified. Our objective was to determine the diagnostic accuracies of electrocardiogram (ECG) and N-terminal Pro-B-type natriuretic peptide (pro-BNP) for left ventricular hypertrophy individually and in combination in hypertensive ED patients. METHODS: Prospective diagnostic study in an academic urban tertiary care hospital ED with annual census of 65,000 visits. Inclusion criteria are as follows: adult ED patients with systolic blood pressure greater than or equal to 160 mm Hg or diastolic blood pressure greater than or equal to 100 mm Hg on 2 or more measurements taken 60 minutes apart. Exclusion criteria are as follows: patients with heart failure, renal insufficiency/failure, acute myocardial infarction, or without recent or scheduled echocardiograms. All patients received echocardiograms and had pro-BNP levels measured using a RAMP point-of-care device (Response Biomedical, Vancouver, BC, Canada). We calculated diagnostic test characteristics with 95% confidence intervals (CIs). RESULTS: A total of 49 patients were enrolled. The average age was 57.9 years, 26.5% were male, and 63.3% were African American. Thirty-two patients (65%) had left ventricular hypertrophy by echocardiogram. Twenty-one (43%) had ECG evidence of left ventricular hypertrophy. Median pro-BNP level was 268 pg/mL. The combination of the 2 tests provided the greatest specificity (94%; 95% CI, 69%-99.7%) and positive predictive value (94%; 95% CI, (68%-99.7%). CONCLUSIONS: The combination of ECG and pro-BNP is a promising screening algorithm for identification of hypertensive ED patients with left ventricular hypertrophy.
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    Myocardial Ischemia on Exercise Stress Echocardiography Testing Is Not Associated with Changes in Troponin T Concentrations
    (The Journal of Applied Laboratory Medicine, 2017) Limkakeng, Alexander T; Drake, Weiying; Lokhnygina, Yuliya; Meyers, Harvey P; Shogilev, Daniel; Christenson, Robert H; Newby, L Kristin
    Background: Some posit that any amount of myocardial ischemia can be detected by high-sensitivity cardiac troponin assays. We hypothesized that patients with myocardial ischemia induced by exercise stress would have significantly higher increases in high-sensitivity cardiac troponin T (hs-cTnT) concentrations than patients without ischemia.Methods: We prospectively recruited for a biorepository 317 adult patients who presented to an academic hospital emergency department for evaluation possible ischemic symptoms and who were scheduled for exercise echocardiography. Blood samples were obtained before stress testing and 2-h post-testing. For this study, plasma hs-cTnT (Roche Diagnostics) concentrations were determined in a core laboratory blinded to clinical status. Absolute and relative changes between baseline and 2-h post-stress measurements were compared between patients with and without ischemia induced by stress testing.Results: The median age was 51 (44.0, 60.0) years, 45.9% were male, and 37.8% were African American. In total, 26 patients (8.1%) had myocardial ischemia induced by exercise. Median baseline, 2-h post-stress, and absolute δ concentrations were, respectively, 6.0, 8.0, and 0.2 ng/L for patients with evidence of ischemia; 3.8, 4.6, and 0.0 ng/L for those without; and 3.9, 4.9, and 0.0 ng/L overall. Baseline and 2-h hs-cTnT concentrations were higher among patients with abnormal stress tests (all P <=0.05), but absolute and relative changes in hs-cTnT concentrations were not significantly different between individuals with ischemia and individuals without.Conclusions: There was no evidence of change in hs-cTnT values in response to exercise stress testing, regardless of the presence of myocardial ischemia.
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    Thrombolysis in myocardial infarction risk score in an observation unit setting.
    (Crit Pathw Cardiol, 2013-09) Chavez, Jean; Srinivasan, Amudan; Ely, Sora; Drake, Weiying; Freeman, Debra; Borawski, Joseph; Chandra, Abhinav; Limkakeng, Alexander T
    OBJECTIVE: The Thrombolysis in Myocardial Infarction (TIMI) score is a validated tool for risk stratification of acute coronary syndrome. We hypothesized that the TIMI risk score would be able to risk stratify patients in observation unit for acute coronary syndrome. METHODS: STUDY DESIGN: Retrospective cohort study of consecutive adult patients placed in an urban academic hospital emergency department observation unit with an average annual census of 65,000 between 2004 and 2007. Exclusion criteria included elevated initial cardiac biomarkers, ST segment changes on ECG, unstable vital signs, or unstable arrhythmias. A composite of significant coronary artery disease (CAD) indicators, including diagnosis of myocardial infarction, percutaneous coronary intervention, coronary artery bypass surgery, or death within 30 days and 1 year, were abstracted via chart review and financial record query. The entire cohort was stratified by TIMI risk scores (0-7) and composite event rates with 95% confidence interval were calculated. RESULTS: In total 2228 patients were analyzed. Average age was 54.5 years, 42.0% were male. The overall median TIMI risk score was 1. Eighty (3.6%) patients had 30-day and 119 (5.3%) had 1-year CAD indicators. There was a trend toward increasing rate of composite CAD indicators at 30 days and 1 year with increasing TIMI score, ranging from a 1.2% event rate at 30 days and 1.9% at 1 year for TIMI score of 0 and 12.5% at 30 days and 21.4% at 1 year for TIMI ≥ 4. CONCLUSIONS: In an observation unit cohort, the TIMI risk score is able to risk stratify patients into low-, moderate-, and high-risk groups.
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    Utility of observation units for young emergency department chest pain patients.
    (Journal of Emergency Medicine, 2013-02) Ely, Sora; Chandra, Abhinav; Mani, Giselle; Drake, Weiying; Freeman, Debbie; Limkakeng, Alexander T
    BACKGROUND: Determining which patients presenting to the Emergency Department (ED) require further work-up for acute coronary syndrome (ACS) can be difficult. The utility of routine observation for cardiac testing in low-risk young adult patients has been questioned. STUDY OBJECTIVES: We investigated the rate of positive findings yielded by routine cardiac observation unit work-up in patients aged 40 years or younger. METHODS: This was a retrospective observational cohort study of patients aged 18-40 years who were evaluated for ACS in an ED-based observation unit. Data were collected by trained abstractors from electronic medical records. RESULTS: A total of 362 patients met inclusion criteria. Of those, 239 received stress testing, yielding five positive and nine indeterminate results. One other patient had acute troponin elevation while under observation. The positive stress test patients and troponin-elevated patient underwent cardiac angiography. Only one positive stress test patient showed significant coronary stenosis and received coronary interventions. In follow-up data, one patient had an adverse cardiac outcome within 1 year of index visit, but no coronary interventions. Thus, only 3 patients had adverse cardiac events, with only one patient warranting intervention discovered by observation unit stress testing and a second via serial cardiac markers. CONCLUSION: Routine observation of symptomatic young adults for ACS had low yield. Observation identified one patient with acute cardiac marker elevation and further stress testing identified only one patient with intervenable ACS, despite a high false-positive rate. This suggests that observation and stress testing should not be routinely performed in this demographic absent other high-risk features.