Anna Marie Chang

The Association Between Emergency Department Crowding and Adverse Cardiovascular Outcomes in Patients with Chest Pain

OBJECTIVES While emergency department (ED) crowding is a worldwide problem, few studies have demonstrated associations between crowding and outcomes. The authors examined whether ED crowding was associated with adverse cardiovascular outcomes in patients with chest pain syndromes (chest pain or related complaints of possible cardiac origin). METHODS A retrospective analysis was performed for patients >or=30 years of age with chest pain syndrome admitted to a tertiary care academic hospital from 1999 through 2006. The authors compared rates of inpatient adverse outcomes from ED triage to hospital discharge, defined as delayed acute myocardial infarction (AMI), heart failure, hypotension, dysrhythmias, and cardiac arrest, which occurred after ED arrival using five separate crowding measures. RESULTS Among 4,574 patients, 251 (4%) patients developed adverse outcomes after ED arrival; 803 (18%) had documented acute coronary syndrome (ACS), and of those, 273 (34%) had AMI. Compared to less crowded times, ACS patients experienced more adverse outcomes at the highest waiting room census (odds ratio [OR] = 3.7, 95% confidence interval [CI] = 1.3 to 11.0) and patient-hours (OR = 5.2, 95% CI = 2.0 to 13.6) and trended toward more adverse outcomes during time of high ED occupancy (OR = 3.1, 95% CI = 1.0 to 9.3). Adverse outcomes were not significantly more frequent during times with the highest number of admitted patients (OR = 1.6, 95% CI = 0.6 to 4.1) or the highest trailing mean length of stay (LOS) for admitted patients transferred to inpatient beds within 6 hours (OR = 1.5, 95% CI = 0.5 to 4.0). Patients with non-ACS chest pain experienced more adverse outcomes during the highest waiting room census (OR = 3.5, 95% CI = 1.4 to 8.4) and patient-hours (OR = 4.3, 95% CI = 2.6 to 7.3), but not occupancy (OR = 1.8, 95% CI = 0.9 to 3.3), number of admitted patients (OR = 0.6, 95% CI 0.4 to 1.1), or trailing LOS for admitted patients (OR = 1.2, 95% CI = 0.6 to 2.0). CONCLUSIONS There was an association between some measures of ED crowding and a higher risk of adverse cardiovascular outcomes in patients with both ACS-related and non-ACS-related chest pain syndrome.

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.

Non–Emergency Department Interventions to Reduce ED Utilization: A Systematic Review

OBJECTIVES Recent health policy changes have focused efforts on reducing emergency department (ED) visits as a way to reduce costs and improve quality of care. This was a systematic review of interventions based outside the ED aimed at reducing ED use. METHODS This study was designed as a systematic review. We reviewed the literature on interventions in five categories: patient education, creation of additional non-ED capacity, managed care, prehospital diversion, and patient financial incentives. Studies written in English, with interventions administered outside of the ED, and a comparison group where ED use was an outcome, were included. Two independent reviewers screened search results using MEDLINE, Cochrane, OAIster, or Scopus. The following data were abstracted from included studies: type of intervention, study design, population, details of intervention, effect on ED use, effect on non-ED health care use, and other health and financial outcomes. Quality of individual articles was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines. RESULTS Of 39 included studies, 34 were observational and five were randomized controlled trials. Two of five studies on patient education found reductions in ED use ranging from 21% to 80%. Out of 10 studies of additional non-ED capacity, four showed decreases of 9% to 54%, and one a 21% increase. Both studies on prehospital diversion found reductions of 3% to 7%. Of 12 studies on managed care, 10 had decreases ranging from 1% to 46%. Nine out of 10 studies on patient financial incentives found decreases of 3% to 50%, and one a 34% increase. Nineteen studies reported effect on non-ED use with mixed results. Seventeen studies included data on health outcomes, but 13 of these only included data on hospitalizations rather than morbidity and mortality. Seven studies included data on cost outcomes. According to the GRADE guidelines, all studies had at least some risk of bias, with four moderate quality, one low quality, and 34 very low quality studies. CONCLUSIONS Many studies have explored interventions based outside the ED to reduce ED use in various populations, with mixed evidence. Approximately two-thirds identified here showed reductions in ED use. The interventions with the greatest number of studies showing reductions in ED use include patient financial incentives and managed care, while the greatest magnitude of reductions were found in patient education. These findings have implications for insurers and policymakers seeking to reduce ED use.

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.

Actual financial comparison of four strategies to evaluate patients with potential acute coronary syndromes

OBJECTIVES Small studies have shown that a negative computed tomography coronary angiogram (CTA) in low-risk chest pain patients predicts a low rate of 30-day adverse events. The authors hypothesized that an immediate CTA strategy would be as effective but less costly than alternative strategies for evaluation of patients with potential acute coronary syndrome (ACS). METHODS The authors retrospectively compared four strategies for evaluation of patients after initial physician determination that the patient required admission and testing to rule out ACS. Patients were frequency-matched by age, race, gender, thrombolysis in myocardial infarction (TIMI) score, and initial electrocardiogram (ECG). The four groups were immediate CTA in the emergency department (ED) without serial markers (n = 98); clinical decision unit/observation unit (CDU) with biomarkers and CTA (n = 102); CDU evaluation with serial cardiac biomarkers and stress testing (n = 154); and usual care, defined as admission with serial biomarkers and hospitalist-directed evaluation (n = 289). The main outcomes were actual cost of care (facility direct and indirect fixed, facility variable direct labor and supply costs), length of stay (LOS), diagnosis of coronary artery disease (CAD), and safety (30-day death or myocardial infarction [MII). RESULTS Patients in each group were of similar age (mean +/- standard deviation [SD] 46 +/- 9 years), race (62% African American), and gender (57% female) and had similar TIMI scores (100% between 0-2). Comparing immediate CTA versus CDU CTA versus CDU stress versus usual care, median costs were less (

Comparison of cardiac risk scores in ED patients with potential acute coronary syndrome

1,240 vs. 2,318 vs. 4,024 vs. 2,913; p < 0.01), and LOS was shorter (8.1 hr vs. 20.9 hr vs. 26.2 hr vs. 30.2 hr; p < 0.01). Diagnosis of CAD was similar (5.1% vs. 5.9% vs. 5.8% vs. 6.6%; p = 0.95), but fewer patients had 30-day death/MI (0% vs. 0% vs. 0.7% vs. 3.1%; p = 0.04) or 30-day readmission (0% vs. 3.2% vs. 2.3% vs. 12.2%; p < 0.01). CONCLUSIONS Compared to the other strategies, immediate CTA was as safe, identified as many patients with CAD, had the lowest cost, had the shortest LOS, and allowed discharge for the majority of patients. Larger prospective studies should confirm safety before immediate CTA replaces other strategies to rule out possible ACS.

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

OBJECTIVE : The ability to risk stratify patients presenting to the emergency department (ED) with potential acute coronary syndrome (ACS) is critical. Several risk scores for patients with definite ACS have been developed, but only the TIMI risk score has been shown to risk stratify ED patients with potential ACS. We compared the prognostic value of the GRACE and PURSUIT risk scores to the TIMI score in the broader ED patient population presenting with potential ACS. METHODS : We performed a secondary analysis of a prospective cohort study that enrolled patients who presented to the ED with potential ACS. Demographics, history, and components of the TIMI, GRACE, and PURSUIT scores were obtained. Follow-up was conducted by structured record review and phone. The main outcome was a composite of 30-day death, nonfatal acute myocardial infarction, and revascularization. The GRACE scores ranged from 0 to 330 and PURSUIT scores ranged from 0 to 18 and were subsequently divided into 8 equivalent strata to correspond with TIMI score range and to facilitate comparison. For each of the 3 risk scores, receiver operating characteristic (ROC) curves were used to compare prediction of 30-day event rates. RESULTS : There were 4743 patients enrolled (mean age: 52.5 ± 13.3; 56% female; 65% black). By 30 days, there were 59 deaths, 172 acute myocardial infarctions, and 175 revascularizations. The area under the curve for TIMI was 0.757 (95% CI: 0.728-0.785); GRACE, 0.728 (95% CI: 0.701-0.755); and PURSUIT, 0.691 (95% CI: 0.662-0.720). CONCLUSION : In this large cohort of ED patients, the TIMI risk score had the best discriminatory ability to predict 30-day cardiovascular events.

Bystander-initiated CPR in an Asian metropolitan: Does the socioeconomic status matter?

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.