Christine M. McCusker

Coronary Computed Tomographic Angiography for Rapid Discharge of Low-Risk Patients With Potential Acute Coronary Syndromes

STUDY OBJECTIVE Coronary computed tomographic (CT) angiography has excellent performance characteristics relative to coronary angiography and exercise or pharmacologic stress testing. We hypothesize that coronary CT angiography can identify a cohort of emergency department (ED) patients with a potential acute coronary syndrome who can be safely discharged with a less than 1% risk of 30-day cardiovascular death or nonfatal myocardial infarction. METHODS We conducted a prospective cohort study at an urban university hospital ED that enrolled consecutive patients with potential acute coronary syndromes and a low TIMI risk score who presented to the ED with symptoms suggestive of a potential acute coronary syndrome and received a coronary CT angiography. Our intervention was either immediate coronary CT angiography in the ED or after a 9- to 12-hour observation period that included cardiac marker determinations, depending on time of day. The main clinical outcome was 30-day cardiovascular death or nonfatal myocardial infarction. RESULTS Five hundred sixty-eight patients with potential acute coronary syndrome were evaluated: 285 of these received coronary CT angiography immediately in the ED and 283 received coronary CT angiography after a brief observation period. Four hundred seventy-six (84%) were discharged home after coronary CT angiography. During the 30-day follow-up period, no patients died of a cardiovascular event (0%; 95% confidence interval [CI] 0% to 0.8%) or sustained a nonfatal myocardial infarction (0%; 95% CI 0 to 0.8%). CONCLUSION ED patients with symptoms concerning for a potential acute coronary syndrome with a low TIMI risk score and a nonischemic initial ECG result can be safely discharged home after a negative coronary CT angiography test result.

One‐year Outcomes Following Coronary Computerized Tomographic Angiography for Evaluation of Emergency Department Patients with Potential Acute Coronary Syndrome

OBJECTIVES Coronary computerized tomographic angiography (CTA) has high correlation with cardiac catheterization and has been shown to be safe and cost-effective when used for rapid evaluation of low-risk chest pain patients from the emergency department (ED). The long-term outcome of patients discharged from the ED with negative coronary CTA has not been well studied. METHODS The authors prospectively evaluated consecutive low- to intermediate-risk patients who received coronary CTA in the ED for evaluation of a potential acute coronary syndrome (ACS). Patients with cocaine use, known cancer, and significant comorbidity reducing life expectancy and those found to have significant disease (stenosis > or = 50% or ejection fraction < 30%) were excluded. Demographics, medical and cardiac history, labs, and electrocardiogram (ECG) results were collected. Patients were followed by telephone contact and record review for 1 year. The main outcome was 1-year cardiovascular death or nonfatal acute myocardial infarction (AMI). RESULTS Of 588 patients who received coronary CTA in the ED, 481 met study criteria. They had a mean (+/-SD) age of 46.1 (+/-8.8) years, 63% were black or African American, and 60% were female. There were 53 patients (11%) rehospitalized and 51 patients (11%) who received further diagnostic testing (stress or catheterization) over the subsequent year. There was one death (0.2%; 95% confidence interval [CI] = 0.01% to 1.15%) with unclear etiology, no AMI (0%; 95% CI = 0 to 0.76%), and no revascularization procedures (0%; 95% CI = 0 to 0.76%) during this time period. CONCLUSIONS Low- to intermediate-risk patients with a Thrombosis In Myocardial Infarction (TIMI) score of 0 to 2 who present to the ED with potential ACS and have a negative coronary CTA have a very low likelihood of cardiovascular events over the ensuing year.

The effect of physician risk tolerance and the presence of an observation unit on decision making for ED patients with chest pain

OBJECTIVES We sought to determine whether risk tolerance as measured by scales (malpractice fear scale [MFS], risk-taking scale [RTS], and stress from uncertainty scale [SUS]) is associated with decisions to admit or use computed tomography (CT) coronary angiogram and decisions to order cardiac markers in emergency department (ED) patients with chest pain. We also studied if the opening of an ED-based observation unit affected the relationship between risk scales and admission decisions. METHODS Data from a prospective study of ED patients 30 years or older with chest pain were used. Risk scales were administered to ED attending physicians who initially evaluated them. Physicians were divided into quartiles for each separate risk scale. Fishers exact test and logistic regression were used for statistical analysis. RESULTS A total of 2872 patients were evaluated by 31 physicians. The most risk-averse quartile of RTS was associated with higher admission rates (78% vs 68%) and greater use of cardiac markers (83% vs 78%) vs the least risk-averse quartile. This was not true for MFS or SUS. Similar associations were observed in low-risk patients (Thrombolysis in Myocardial Infarction risk score of 0 or 1). The observation unit was not associated with a higher admission rate and did not modify the relationship between risk scales and admission rates. CONCLUSION The RTS was associated with the decision to admit or use computed tomography coronary angiogram, as well as the use of cardiac markers, whereas the MFS and SUS were not. The observation unit did not affect admission rates and nor did it affect how physicians risk tolerance affects admission decisions.

Lack of association between left bundle-branch block and acute myocardial infarction in symptomatic ED patients !

OBJECTIVE Guidelines recommend treating patients with a new or presumed new left bundle-branch block (LBBB) similar to those with an acute ST-segment elevation myocardial infarction. It is often unclear which emergency department (ED) patients with potentially ischemic symptoms actually have an acute myocardial infarction (AMI), even in the setting of LBBB. Our null hypothesis was that in ED patients with potential AMI, the presence of a new or presumed new LBBB would not predict an increased likelihood of AMI. METHODS This was an observational cohort study. Patients older than 30 years who presented with chest pain or other ischemic equivalent and had an electrocardiogram (ECG) to evaluate potential acute coronary syndrome (ACS) were enrolled. Data collected include demographics, history, ECG, and cardiac markers. Electrocardiograms were classified according to the standardized guidelines, including LBBB not known to be old (new or presumed new LBBB), LBBB known to be old, or no LBBB. The hospital course was followed, and 30-day follow-up was performed on all patients. Our main outcome was AMI. RESULTS There were 7937 visits (mean age, 54.3 +/- 15 years, 57% female, 68% black): 55 had new or presumed new LBBB, 136 had old LBBB, and 7746 had no LBBB. The rate of AMI was not significantly different between the 3 groups (7.3% vs 5.2% vs 6.1%; P = .75). Revascularization (7.8% vs old 5.2% vs 4.3%; P = .04) and coronary artery disease were more common in patients with new or presumed new LBBB (19.2% vs 11.9% vs 10.1%; P = .0004). CONCLUSIONS Despite guideline recommendations that patients with potential ACS and new or presumed new LBBB should be treated similar to STEMI, ED patients with a new or presumed new LBBB are not at increased risk of AMI. In fact, the presence of LBBB, whether new or old, did not predict AMI. Caution should be used in applying recommendations derived from patients with definite AMI to ED patients with potential ACS that may or may not be sustaining an AMI.

Combining Thrombolysis in Myocardial Infarction risk score and clear-cut alternative diagnosis for chest pain risk stratification

OBJECTIVE The Thrombolysis in Myocardial Infarction (TIMI) risk score is a validated risk stratification tool useful in patients with definite and potential acute coronary syndromes (ACS) but does not identify patients safe for discharge from the emergency department (ED). Likewise, the use of a clear-cut alternative noncardiac diagnosis risk stratifies patients but does not identify a group safe for discharge. We hypothesized that the presence of an alternative diagnosis in patients with a TIMI risk score less than 2 might identify a cohort of patients safe for ED discharge. METHODS In prospective cohort study, we enrolled ED patients with potential ACS. Data included demographics, medical history, components of the TIMI risk score, and whether the treating physician ascribed the condition to an alternative noncardiac diagnosis. Investigators followed the patients through the hospital course, and 30-day follow-up was done. The main outcome was 30-day death, myocardial infarction, or revascularization. RESULTS A total of 3169 patients were enrolled (mean age, 53.6+/-14 years; 45% men; 67% black). There were 991 patients (31%) with an alternative diagnosis, 980 patients with a TIMI risk score of 0, and 828 with a TIMI score of 1. At low levels of TIMI risk (<3), adding in a clinical impression of an alternative diagnosis did not reduce risk; at higher levels of TIMI risk, it did. The incidence of 30-day death, myocardial infarction, or revascularization for patients with a clinical impression of an alternative diagnosis and a TIMI score of 0 was 2.9% (95% confidence interval, 1.6%-5.0%). CONCLUSIONS The TIMI risk score stratifies patients with and without an alternative diagnosis. Unfortunately, patients with both a low TIMI risk score and a clinical impression of an alternative noncardiac diagnosis still have a risk of 30-day adverse events that is not low enough to allow safe discharge from the ED.

Relationship Between Cocaine Use and Coronary Artery Disease in Patients With Symptoms Consistent With an Acute Coronary Syndrome

OBJECTIVES Observational studies of patients with cocaine-associated myocardial infarction have suggested more coronary disease than expected on the basis of patient age. The study objective was to determine whether cocaine use is associated with coronary disease in low- to intermediate-risk emergency department (ED) patients with potential acute coronary syndrome (ACS). METHODS The authors conducted a cross-sectional study of low- to intermediate-risk patients<60 years of age who received coronary computerized tomographic angiography (CTA) for evaluation of coronary artery disease (CAD) in the ED. Patients were classified into three groups with respect to CAD: maximal stenosis <25%, 25% to 49%, and ≥50%. Prespecified multivariate modeling (generalized estimating equations) was used to assess relationship between cocaine and CAD. RESULTS Of 912 enrolled patients, 157 (17%) used cocaine. A total of 231 patients had CAD ≥25%; 111 had CAD ≥50%. In univariate analysis, cocaine use was not associated with a lesion 25% or greater (12% vs. 14%; relative risk [RR]=0.89, 95% confidence interval [CI]=0.5 to 1.4) or 50% or greater (12% vs. 11%; RR=1.15, 95% CI=0.6 to 2.3). In multivariate modeling adjusting for age, race, sex, cardiac risk factors, and Thrombosis in Myocardial Infarction (TIMI) score, cocaine use was not associated with the presence of any coronary lesion (adjusted RR=0.95, 95% CI=0.69 to 1.31) or coronary lesions 50% or greater (adjusted RR=0.78, 95% CI=0.45 to 1.38). There was also no relationship between repetitive cocaine use and coronary calcifications or between recent cocaine use and CAD. CONCLUSIONS In symptomatic ED patients at low to intermediate risk of an ACS, cocaine use was not associated with an increased likelihood of coronary disease after adjustment for age, race, sex, and other risk factors for coronary disease.

Young patients with chest pain: 1-year outcomes

OBJECTIVE Prior studies found that young adult chest pain patients without known cardiac disease with either no cardiac risk factors or a normal electrocardiogram (ECG) are at low risk (<1%) for acute coronary syndromes (ACS) and 30-day cardiovascular events. Longer-term event rates in this subset of patients are unknown. We hypothesized that patients younger than 40 years without past cardiac history and a normal ECG are at less than 1% risk for 1-year adverse cardiovascular events. METHODS We conducted a prospective cohort study in an urban university emergency department evaluating patients younger than 40 years who received an ECG for evaluation of potential ACS. Cocaine users, cancer patients, and patients with a history of myocardial infarction or revascularization were excluded. Structured data collection at presentation included demographics, chest pain description, history, laboratory results, and ECG data. Hospital course was followed. Follow-up was obtained by telephone, record review, and social security death index search. Our main outcome was 1-year adverse cardiovascular events (death; acute myocardial infarction [AMI]; or revascularization-percutaneous coronary intervention [PCI] or coronary artery bypass graft). Descriptive statistics and 95% confidence intervals were used. RESULTS Of 3846 chest pain patients, 609 met criteria. Of those, 35.5% were admitted. Patients had a mean age of 34.8 years (SD, 3.8 years). They were most often female (57.6%) and black (69.5%). There were 7 patients (1.1%; 95% CI, 0.5%-2.4%) with adverse cardiovascular events over the year. Of the subset of 560 patients with a normal/nonspecific ECG, there were 2 deaths (0.4%), 3 AMI (0.5%), and 2 PCIs (0.4%) by 1 year for a composite adverse cardiovascular event rate of 6 (1.1%; 95% CI, 0.4%-2.3%). Of the subset of 269 patients with no cardiac risk factors and a normal/nonspecific ECG, there were no deaths, 1 AMI, and 1 PCI for a composite adverse cardiovascular event rate at 1 year of 0.3% (0.01%-2.1%). The addition of an initial cardiac marker to this group resulted in a cohort that was event-free at 1 year (95% CI, 0%-1.4%). CONCLUSIONS Patients younger than 40 years without a cardiac history who present to the ED with symptoms consistent with ACS but have either no risk factors or a normal or nonspecific ECG have a very low rate of adverse events during the subsequent year.

Medication history taking in emergency department triage is inaccurate and incomplete.

OBJECTIVES Medication error prevention has become a priority in health care. The Joint Commission recommends that a list of medications, dosages, and allergies be obtained from all patients. The authors sought to determine the accuracy of medication history taking in emergency department (ED) triage. The hypothesis was that there would be significant discrepancies between medications listed in triage and those the patient was actually taking. METHODS This was a prospective, cross-sectional survey of adult patients presenting to the ED. As a part of regular care, nurses recorded a medication list during triage in the electronic medical record (EMR). For this study, the triage medication list was rechecked during an independent patient interview. RESULTS Of 1,797 patients approached, 1,657 completed the survey (92%). The mean age was 39 years (standard deviation [SD] ±16 years). Discrepancies in medication lists obtained during triage were documented in 626 (37%) patients. Discontinued medications (163, 9.8%) were included, additional medications (463, 27.9%) were omitted, and 632 patients (38%) reported taking a nonprescription medication not listed in the EMR. CONCLUSIONS Medication histories performed in ED triage are inaccurate and incomplete.

The effect of ED crowding on education

OBJECTIVE We studied if emergency department (ED) crowding affects the quality of resident and medical student education on individual patient encounters. METHODS We performed a cross-sectional study of a ED faculty-learner interactions over a 5-week period in an academic ED. Research assistants administered surveys to residents and senior medical students assessing attending physicians on 4 domains (teaching, clinical care, approachability, and helpfulness) using a scale (ER score for teaching on individual patients) validated for use during ED rotations. Each domain was assessed on a 5-point scale with a highest score of 20 representing superb/outstanding. We tested the association between measures of ED crowding (waiting room number, occupancy, number of admitted patients, and patient-hours) at the time of assessment with the ER score and individual domain scores using correlation coefficients and regression analysis with clustering on the attending physician. RESULTS Forty-three residents (22 ED, 21 non-ED) and 3 medical students assessed 34 attending physicians in 352 separate encounters. Median ER score was 16/20 (interquartile range, 12-16). Emergency department crowding levels and ER scores on individual patients were not significantly correlated, nor were ED crowding and individual domains. In the adjusted analysis, ED crowding was not associated with an ER score of 16 or higher, nor was any ED crowding measure associated individual assessments of teaching, clinical care, approachability, or helpfulness. CONCLUSION Emergency department crowding is not associated with the quality of education on individual patients.

Medications from the web: use of online pharmacies by emergency department patients.

BACKGROUND Internet access and online pharmacies are a resource for purchasing medications. It is unclear if this venue is being used by emergency department (ED) patients to obtain medications. OBJECTIVE We sought to determine the frequency of and to characterize online pharmacy use by ED patients. We hypothesized that students and younger patients would be more likely than others to obtain medications via online pharmacies due to their familiarity with the Internet. METHODS This prospective, cross-sectional survey occurred in an urban university ED. We enrolled a convenience sample of adult patients. The study was Institutional Review Board approved, and informed consent was obtained. To determine differences between online pharmacy users and non-users, chi-squared or Fishers exact tests were used for categorical data, and t-test or Wilcoxon rank sum tests were used for continuous variables. RESULTS There were 1657 patients who completed the survey. The mean age was 39 years, standard deviation 16 years; 947/1657 (57%) reported awareness of online pharmacies; 89/1657 (5.4%) patients used the Internet to order medications. More patients with prescription plans ordered medications from online pharmacies (94.3% vs. 70%; p<0.0001), and Internet users were more commonly on multiple medications (median 3 vs. 1; p<0.0001). There was no difference in age (39.4 vs. 41 years; p=0.2) or student status (13.8% vs. 14.9%; p=0.8) between the two groups. CONCLUSIONS Approximately 5% of ED patients used the Internet to obtain medications. Contrary to our hypothesis, younger patients were not more likely to use the Internet for medications. Patients on multiple medications and those with prescription plans used online pharmacies more frequently.