Clinical correlates and prognostic significance of early negative exercise tolerance test in patients with acute chest pain seen in the hospital emergency department

High-Risk Chief Complaints I: Chest Pain-The Big Three (an Update)

Nontraumatic chest pain is a frequent concern of emergency department patients, with causes that range from benign to immediately life threatening. Identifying those patients who require immediate/urgent intervention remains challenging and is a high-risk area for emergency medicine physicians where incorrect or delayed diagnosis may lead to significant morbidity and mortality. This article focuses on the 3 most prevalent diagnoses associated with adverse outcomes in patients presenting with nontraumatic chest pain, acute coronary syndrome, thoracic aortic dissection, and pulmonary embolism. Important aspects of clinical evaluation, diagnostic testing, treatment, and disposition and other less common causes of lethal chest pain are also discussed.

Compliance with stress testing in patients discharged from the emergency department following a diagnosis of low-risk chest pain

OBJECTIVE

To determine rates of compliance with outpatient stress testing in patients with a diagnosis of low-risk chest pain, reasons for non-compliance and incidence of adverse cardiac events (ACE).

METHODS

This was a prospective study of 79 patients who were discharged from the emergency department with low-risk chest pain. Patients were followed-up by phone interview.

RESULTS

36.7% of patients completed EST within 30 days, 2.5% of patients completed their EST within the recommended 72 h. A lack of time was the most common reason for non-compliance and was seen in 32.0% of patients. 20% of ESTs were cancelled by the primary care physician (PCP). 12% of patients were non-compliant, as they believed the pain to be non-cardiac. There were no documented ACEs in the study.

CONCLUSIONS

Compliance with EST is poor in patients with low-risk chest pain. Non-compliance is related to a number of factors including work commitments, cancellation of studies by the PCP and patients beliefs about the nature of their chest pain.

Coronary computed tomographic angiography in the emergency room: state of the art

Chest pain is a common complaint in the emergency department often necessitating testing to exclude underlying obstructive coronary artery disease. While the traditional evaluation of patients with suspected acute coronary syndrome often consists of serial electrocardiograms and cardiac biomarkers, followed by selective use of stress testing for further risk stratification, this approach is costly and inefficient. Recently, coronary computed tomographic angiography (CTA) has offered an alternative approach with a high sensitivity and negative predictive value to exclude obstructive coronary artery disease that can rapidly identify patients with low rates of downstream major adverse cardiac events. In this review, the authors provide an overview of available data on the use of CTA for evaluating acute chest pain, while emphasizing its advantages and disadvantages compared to existing strategies. In addition, we provide a suggested algorithm to identify how CTA can be incorporated into the evaluation of acute chest pain and discuss tips for successful implementation of CTA in the emergency department.

Risk scores prognostic implementation in patients with chest pain and nondiagnostic electrocardiograms

BACKGROUND

Several risk scores are available for prognostic purpose in patients presenting with chest pain.

AIM

The aim of this study was to compare Grace, Pursuit, Thrombolysis in Myocardial Infarction (TIMI), Goldman, Sanchis, and Florence Prediction Rule (FPR) to exercise electrocardiogram (ECG), decision making, and outcome in the emergency setting.

METHODS

Patients with nondiagnostic ECGs and normal troponins and without history of coronary disease underwent exercise ECG. Patients with positive testing underwent coronary angiography; otherwise, they were discharged. End point was the composite of coronary stenosis at angiography or cardiovascular death, myocardial infarction, angina, and revascularization at 12-month follow-up.

RESULTS

Of 508 patients considered, 320 had no history of coronary disease: 29 were unable to perform exercise testing, and finally, 291 were enrolled. Areas under the receiver operating characteristic curves for Grace, Pursuit, TIMI, Goldman, Sanchis, and FPR were 0.59, 0.68, 0.69, 0.543, 0.66, and 0.74, respectively (P < .05 FPR vs Goldman and Grace). In patients with negative exercise ECG and overall low risk score, only the FPR effectively succeeded in recognizing those who achieved the end point; in patients with high risk score, the additional presence of carotid stenosis and recurrent angina predicted the end point (odds ratio, 12 and 5, respectively). Overall, logistic regression analysis including exercise ECG, coronary risk factors, and risk scores showed that exercise ECG was an independent predictor of coronary events (P < .001).

CONCLUSIONS

The FPR effectively succeeds in ruling out coronary events in patients categorized with overall low risk score. Exercise ECG, nonetheless being an independent predictor of coronary events could be considered questionable in this subset of patients.

The evolution of chest pain pathways

Patients presenting to the emergency department with chest pain require prompt identification and referral, as early treatment of patients with an acute coronary syndrome (ACS) is crucial to decrease morbidity and mortality (Steurer et al, Emerg Med J. 2010;27:896-902). Although rule-in ACS is critical and time dependant, other difficulties arise during the rule-out ACS process (Steurer et al, Emerg Med J. 2010;27:896-902). Inappropriate discharge of patients with misdiagnosed acute myocardial infarction is associated with significant morbidity and mortality. Concerns relating to inappropriate discharge result in readmission with resultant lengthy hospital stays, high costs, and contribute to overcrowding and bed block (Amsterdam et al, J Am Coll Cardiol. 2002;40:251-256; Cardiol Clin. 2005;23:503-516; Furtado et al, Emerg Med. In press; Karlson, Am J Cardiol. 1991;68:171-175; Ng et al, Am J Cardiol. 2001;88:611-617; Ramakrishna et al, Mayo Clin Proc. 2005;80:322-329; Stowers, Crit Pathw Cardiol. 2003;2:88-94). The challenge of chest pain diagnosis has led to a number of associated problems within the health care system. The growing need for improvements in consistency of patient care, resource efficiency, and quality of patient healthcare has led to the development of chest pain pathways (Erhardt et al, Eur Heart J. 2002;23:1153-1176). The development and implementation of chest pain pathways is not without difficulties. These may arise from differences in the management approaches of health practitioners, poor adherence to guidelines, and concerns for costs. New procedures such as new cardiac injury markers, stress testing, and specialized chest pain units have led to a reduction in admission rates and length of stay, reduced costs, and a reduction of inappropriate discharge of patients with ischemic heart disease.

Contrast stress-echocardiography predicts cardiac events in patients with suspected acute coronary syndrome but nondiagnostic electrocardiogram and normal 12-hour troponin

BACKGROUND

No large study has demonstrated that any stress test can risk-stratify future hard cardiac events (cardiac death or myocardial infarction) in patients with suspected acute coronary syndromes (ACS), nondiagnostic electrocardiographic (ECG) findings, and normal troponin levels. The aim of this study was to test the hypothesis that combined contrast wall motion and myocardial perfusion echocardiographic assessment (cMCE) during stress echocardiography can predict long-term hard cardiac events in patients with suspected ACS, nondiagnostic ECG findings, and normal troponin.

METHODS

A total of 545 patients referred for contrast stress echocardiography from the emergency department for suspected ACS but nondiagnostic ECG findings and normal troponin levels at 12 hours were followed up for cardiac events. Patients underwent dipyridamole-atropine echocardiography with adjunctive myocardial perfusion imaging using a commercially available ultrasound contrast medium (SonoVue).

RESULTS

During a median follow-up period of 12 months, 25 cardiac events (4.6%) occurred (no deaths, 12 nonfatal myocardial infarctions, 13 episodes of unstable angina). Abnormal findings on cMCE were the most significant predictor of both hard cardiac events (hazard ratio, 22.8; 95% confidence interval, 2.9-176.7) and the combined (cardiac death, myocardial infarction, or unstable angina requiring revascularization) end point (hazard ratio, 10.7; 95% confidence interval, 3.7-31.3). The inclusion of the cMCE variable significantly improved multivariate models, determining lower Akaike information criterion values and higher discrimination ability.

CONCLUSIONS

cMCE during contrast stress echocardiography provided independent information for predicting hard and combined cardiac events beyond that predicted by stress wall motion abnormalities in patients with suspected ACS, nondiagnostic ECG findings, and normal troponin levels.

Compliance with outpatient stress testing in low-risk patients presenting to the emergency department with chest pain

Recent evidence suggests that stress testing prior to emergency department (ED) release in low-risk chest pain patients identifies those who can be safely discharged home. When immediate stress testing is not feasible, rapid outpatient stress testing has been recommended. The objective of this study was to determine compliance rate and incidence of adverse cardiac events in patients presenting to the ED with low-risk chest pain referred for outpatient stress testing. Retrospective chart and social security death index review were conducted in 448 consecutive chest pain patients who presented to a university hospital and level I trauma center between April 30 and December 31, 2007. Patients were evaluated with an accelerated chest pain protocol defined as a 4-hour ED rule out and referral for outpatient stress testing within 72 hours of ED release. Only patients without known cardiac disease, a thrombolysis in myocardial infarction risk score ≤2, negative serial ECGs and cardiac biomarkers, and benign ED course were eligible for the protocol. Primary outcome measures included compliance with outpatient stress testing and documented 30-day incidence of adverse cardiac events following ED release. The social security death index was queried to determine 12-month incidence of all-cause mortality in enrolled patients. Logistic regression analysis of characteristics associated with outpatient stress test compliance was determined and incidence of adverse cardiac events in those who were and were not compliant with outpatient stress testing was compared. Significance was set at P < 0.05. A total of 188 patients (42%) completed outpatient stress testing, but only 27 (6%) completed testing within 72 hours of ED discharge. Compliance was correlated with insurance and race, but not patient age, gender, or thrombolysis in myocardial infarction risk score. No significant differences in adverse cardiac events were documented in patients who did and did not comply with outpatient stress testing. Compliance with outpatient stress testing is poor in low-risk chest pain patients following ED release. Despite poor compliance, the documented incidence of adverse cardiac events in this low-risk cohort was lower than that reported in patients with negative provocative testing prior to ED release.

Usefulness of contrast stress-echocardiography or exercise-electrocardiography to predict long-term acute coronary syndromes in patients presenting with chest pain without electrocardiographic abnormalities or 12-hour troponin elevation

The evaluation of patients presenting to the hospital with a recent episode of chest pain suggestive of myocardial ischemia, nondiagnostic electrocardiographic findings, and normal 12-hour cardiac troponin levels remains a challenge for the clinician. We selected 1,081 consecutive patients who presented to the emergency department during 2008 for a chest pain complaint of suspected cardiac origin without significant electrocardiographic abnormalities or troponin elevation. These patients underwent either contrast-enhanced stress-echocardiography with myocardial perfusion imaging or exercise-electrocardiography within 5 days of the index admission. We analyzed their 1-year cardiac outcome (i.e., unstable angina, myocardial infarction, or cardiac death). A post test likelihood of cardiac events was determined on the basis of the results of the provocative testing. Significantly better event-free survival (log-rank p <0.0001) was found for both hard (cardiac death and nonfatal myocardial infarction) and combined (acute coronary syndrome) end points in patients with normal contrast-enhanced stress-echocardiographic findings. However, this was not the case for patients in the exercise-electrocardiographic group, for whom event-free survival was not significantly different among the 3 possible result categories (normal, indeterminate, and abnormal test findings; log-rank p = NS). In conclusion, inducible ischemia detected by contrast-enhanced stress-echocardiography predicted the 1-year incidence of acute coronary syndrome (11.3% for positive vs 0.8% for negative results). However, this was not the case for exercise-electrocardiography, with a 2.7%, 2.3%, and 2.9% 1-year incidence of acute coronary syndromes for positive, negative, and indeterminate results, respectively.

Testing of low-risk patients presenting to the emergency department with chest pain: a scientific statement from the American Heart Association

The management of low-risk patients presenting to emergency departments is a common and challenging clinical problem entailing 8 million emergency department visits annually. Although a majority of these patients do not have a life-threatening condition, the clinician must distinguish between those who require urgent treatment of a serious problem and those with more benign entities who do not require admission. Inadvertent discharge of patients with acute coronary syndrome from the emergency department is associated with increased mortality and liability, whereas inappropriate admission of patients without serious disease is neither indicated nor cost-effective. Clinical judgment and basic clinical tools (history, physical examination, and electrocardiogram) remain primary in meeting this challenge and affording early identification of low-risk patients with chest pain. Additionally, established and newer diagnostic methods have extended clinicians' diagnostic capacity in this setting. Low-risk patients presenting with chest pain are increasingly managed in chest pain units in which accelerated diagnostic protocols are performed, comprising serial electrocardiograms and cardiac injury markers to exclude acute coronary syndrome. Patients with negative findings usually complete the accelerated diagnostic protocol with a confirmatory test to exclude ischemia. This is typically an exercise treadmill test or a cardiac imaging study if the exercise treadmill test is not applicable. Rest myocardial perfusion imaging has assumed an important role in this setting. Computed tomography coronary angiography has also shown promise in this setting. A negative accelerated diagnostic protocol evaluation allows discharge, whereas patients with positive findings are admitted. This approach has been found to be safe, accurate, and cost-effective in low-risk patients presenting with chest pain.

High-risk chief complaints I: chest pain--the big three

Chest pain is one of the most frequently seen chief complaints in patients presenting to emergency departments, and is considered to be a "high-risk" chief complaint. The differential diagnosis for chest pain is broad, and potential causes range from the benign to the immediately life-threatening. Although many (if not most) emergency department patients with chest pain do not have an immediately life-threatening condition, correct diagnoses can be difficult to make, incorrect diagnoses may lead to catastrophic therapies, and failure to make a timely diagnosis may contribute to significant morbidity and mortality. Several atraumatic "high-risk" causes of chest pain are discussed in this article, including myocardial infarction and ischemia, thoracic aortic dissection, and pulmonary embolism. Also included are brief discussions of tension pneumothorax, esophageal perforation, and cardiac tamponade.

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.

Efficacy of coronary revascularization in patients with acute chest pain managed in a chest pain unit

OBJECTIVE

To investigate the safety of discharge of patients deemed at low risk of cardiac events after evaluation in a chest pain unit and to determine the prognostic effect of revascularization of patients deemed at high risk.

PATIENTS AND METHODS

The study population consisted of 1088 patients presenting at the emergency department from January 15, 2001, to September 1, 2006, with chest pain but without ischemia on electrocardiography or troponin elevation. Patients were managed by a chest pain unit protocol that included early exercise testing. Three groups of patients were distinguished: (1) those discharged after exercise testing (424 [39%]); (2) those in whom unstable angina was ruled out after in-hospital evaluation (208 [19%]); and (3) those in whom unstable angina was confirmed or not ruled out (456 [42%]). Of the 456 patients in group 3, 183 (40%) were revascularized at the index episode. The primary end point was the occurrence of myocardial infarction or death within 1 year. Adjustments were made for patient characteristics and a propensity score for revascularization (c statistic [0.83]).

RESULTS

Groups 1 and 2 showed lower rates of the primary end point than group 3 (group 1: 7 [1.7%]; group 2: 1 [0.5%]; group 3: 62 [13.6%]; P=.001). In group 3, revascularization at the index episode did not reduce the primary end point in the univariate (22 [12%] vs 29 [11%]; P=.80) and multivariate (hazard ratio, 1.4; 95% confidence interval, 0.7-2.5; P=.40) analyses. In-hospital revascularization decreased the need for postdischarge revascularization (hazard ratio, 0.3; 95% confidence interval, 0.1-0.7; P=.01).

CONCLUSION

Chest pain unit protocols are associated with safe patient discharge. Although early revascularizations may decrease the need for postdischarge revascularizations, they may not improve 1-year outcomes by reducing the number of myocardial infarctions or deaths.

Sixty-four-slice computed tomography of the coronary arteries: cost-effectiveness analysis of patients presenting to the emergency department with low-risk chest pain

OBJECTIVES

The aim was to use a computer model to estimate the cost-effectiveness of 64-slice multidetector computed tomography (MDCT) of the coronary arteries in the emergency department (ED) compared to an observation unit (OU) stay plus stress electrocardiogram (ECG) or stress echocardiography for the evaluation of low-risk chest pain patients presenting to the ED.

METHODS

A decision analytic model was developed to compare health outcomes and costs that result from three different risk stratification strategies for low-risk chest pain patients in the ED: stress ECG testing after OU care, stress echocardiography after OU care, and MDCT with no OU care. Three patient populations were modeled with the prevalence of symptomatic coronary artery disease (CAD) being very low risk, 2%; low risk, 6% (base case); and moderate risk, 10%. Outcomes were measured as quality-adjusted life years (QALYs). Incremental cost-effectiveness ratios (ICERs), the ratio of change in costs of one test over another to the change in QALY, were calculated for comparisons between each strategy. Sensitivity analyses were conducted to test the robustness of the results to assumptions regarding the characteristics of the risk stratification strategies, costs, utility weights, and likelihood of events.

RESULTS

In the base case, the mean (+/- standard deviation [SD]) costs and QALYs for each risk stratification strategy were MDCT arm $2,684 (+/- $1,773 to $4,418) and 24.69 (+/- 24.54 to 24.76) QALYs, stress echocardiography arm $3,265 (+/- $2,383 to $4,836) and 24.63 (+/- 24.28 to 24.74) QALYs, and stress ECG arm $3,461 (+/- $2,533 to $4,996) and 24.59 (+/- 24.21 to 24.75) QALYs. The MDCT dominated (less costly and more effective) both OU plus stress echocardiography and OU plus stress ECG. This resulted in an ICER where the MDCT arm dominated the stress echocardiography arm (95% confidence interval [CI] = dominant to $29,738) and where MDCT dominated the ECG arm (95% CI = dominant to $7,332). The MDCT risk stratification arm also dominated stress echocardiography and stress ECG in the 2 and 10% prevalence scenarios, which demonstrated the same ICER trends as the 6% prevalence CAD base case. The thresholds where the MDCT arm remained a cost-saving strategy compared to the other risk stratification strategies were cost of MDCT, < $2,097; cost of OU care, > $1,092; prevalence of CAD, < 70%; MDCT specificity, > 65%; and a MDCT indeterminate rate, < 30%.

CONCLUSIONS

In this computer-based model analysis, the MDCT risk stratification strategy is less costly and more effective than both OU-based stress echocardiography and stress ECG risk stratification strategies in chest pain patients presenting to the ED with low to moderate prevalence of CAD.

Measurement of coronary calcium scores by electron beam computed tomography or exercise testing as initial diagnostic tool in low-risk patients with suspected coronary artery disease

We determined the efficiency of a screening protocol based on coronary calcium scores (CCS) compared with exercise testing in patients with suspected coronary artery disease (CAD), a normal ECG and troponin levels. Three-hundred-and-four patients were enrolled in a screening protocol including CCS by electron beam computed tomography (Agatston score), and exercise testing. Decision-making was based on CCS. When CCS>or=400, coronary angiography (CAG) was recommended. When CCS<10, patients were discharged. Exercise tests were graded as positive, negative or nondiagnostic. The combined endpoint was defined as coronary event or obstructive CAD at CAG. During 12+/-4 months, CCS>or=400, 10-399 and <10 were found in 42, 103 and 159 patients and the combined endpoint occurred in 24 (57%), 14 (14%) and 0 patients (0%), respectively. In 22 patients (7%), myocardial perfusion scintigraphy was performed instead of exercise testing due to the inability to perform an exercise test. A positive, nondiagnostic and negative exercise test result was found in 37, 76 and 191 patients, and the combined endpoint occurred in 11 (30%), 15 (20%) and 12 patients (6%), respectively. Receiver-operator characteristics analysis showed that the area under the curve of 0.89 (95% CI: 0.85-0.93) for CCS was superior to 0.69 (95% CI: 0.61-0.78) for exercise testing (P<0.0001). In conclusion, measurement of CCS is an appropriate initial screening test in a well-defined low-risk population with suspected CAD.

Yield of early rest and stress myocardial perfusion single-photon emission computed tomography and electrocardiographic exercise test in patients with atypical chest pain, nondiagnostic electrocardiogram, and negative biochemical markers in the emergency department

There are no studies in which diagnostic yield of early rest myocardial perfusion gated single-photon emission computed tomography (SPECT), electrocardiographic exercise testing, and stress SPECT were compared in patients with atypical chest pain, nondiagnostic electrocardiograms (ECGs), and negative markers of myocardial damage in the emergency department. A prospective study of 96 patients who presented with atypical chest pain and nondiagnostic ECG, but without elevated markers of necrosis, was performed. All underwent rest gated SPECT using technetium-99m methoxyisobutyl isonitrile within 6 hours after pain subsided followed by an electrocardiographic exercise test to obtain stress-rest SPECT images. After 1 year, there were no deaths and coronary artery disease was confirmed in only 5 patients. Negative predictive values of the 3 techniques were high (99%, 96%, and 100%, respectively), but positive predictive values were low (27%, 22%, and 14%, respectively). Sensitivities of early SPECT (80%) and stress SPECT (100%) were higher than for the electrocardiographic exercise test (40%). In conclusion, in patients with atypical chest pain, nondiagnostic ECG, and negative biochemical markers, negative predictive values of the 3 tests analyzed are very high. The sensitivity of radionuclide tests is higher, but their widespread use does not appear warranted because their positive predictive value and incidence of complications is low.

Impact of a negative prior stress test on emergency physician disposition decision in ED patients with chest pain syndromes

OBJECTIVE

Many emergency department (ED) patients with potential acute coronary syndromes (ACS) have prior visits and prior cardiac testing; however, the effect of knowledge of prior testing on the emergency physician disposition decision making is not known. We studied the impact of prior noninvasive testing (ie, stress testing) for myocardial ischemia on disposition decision making in ED patients with potential ACS.

METHODS

We performed a prospective cohort study of ED patients with chest pain who received an electrocardiogram for potential ACS. Data included demographics, medical history, stress test history, and TIMI risk score. Patients were followed in-house; 30-day telephone interviews were performed for follow-up. Main outcomes were ED disposition (admit/discharge) and a composite of 30-day death, acute myocardial infarction, and revascularization stratified on the basis of prior stress testing known at the time of presentation. Standard statistical techniques were used with 95% confidence intervals (CI).

RESULTS

There were 1853 patients enrolled and 97% had follow-up. Patients had a mean age of 53 +/- 14 years; 60% were women, 67% were black. There were 1491 (79%) patients without a prior stress test, 291 (16%) had a normal prior stress test result, and 89 (5%) had an abnormal prior stress test result. Admission rates were 92% (95% CI, 87%-98%) for patients with a prior abnormal stress test, 73% (95% CI, 67%-78%) for patients with a normal prior stress test, and 70% (95% CI, 67%-72%) for patients without a prior stress test. Adverse outcomes were the highest among patients with prior abnormal stress test but did not differ significantly between patients with no prior stress test and patients with prior normal stress test (10.1% [95% CI, 3.6-16.7%] vs 5.2% [95% CI, 4.1-6.4%] vs 4.8% [95% CI, 2.4-7.3%]).

CONCLUSION

Patients without prior stress tests and patients with prior normal stress tests were admitted for potential ACS at the same rate and had the same 30-day cardiovascular event rates. This suggests that prior stress testing does not affect subsequent disposition decisions. Perhaps cardiac catheterization or computed tomography coronary angiograms would have more of an impact on subsequent visits, making them potentially more cost-effective in the low-risk patient.

The diagnostic accuracy of 64-slice computed tomography coronary angiography compared with stress nuclear imaging in emergency department low-risk chest pain patients

STUDY OBJECTIVE

We compared the accuracy of multidetector computed tomography (CT) coronary angiography with stress nuclear imaging for the detection of an acute coronary syndrome or 30-day major adverse cardiac events in low-risk chest pain patients.

METHODS

This was a prospective study of the diagnostic accuracy of myocardial perfusion imaging and multidetector CT in low-risk chest pain patients. The target condition was an acute coronary syndrome (confirmed >70% coronary stenosis on coronary artery catheterization) or major adverse cardiac events within 30 days. Patients were low risk by Reilly/Goldman criteria and had negative serial ECGs and cardiac markers. All had both rest/stress sestamibi nuclear imaging and multidetector CT. Patients with abnormal stress nuclear imaging results (reversible perfusion defects) or multidetector CT results (stenosis >50% or calcium score >400) were considered for cardiac catheterization, and those with discordant results had a greater than 30-day reevaluation (including ECG) by a cardiologist. All were followed up for evidence of major adverse cardiac events within 30 days by review of hospital records and structured telephone interview. Primary outcomes were the accuracy of multidetector CT and myocardial perfusion imaging for the detection of an acute coronary syndrome and 30-day major adverse cardiac events.

RESULTS

Of the 92 patients, 7 (8%) were excluded because of uninterpretable multidetector CT scans. Of the remaining 85 study patients (49+/-11 years, 53% men), 7 (8%) were found to have the target condition, with all having significant coronary stenosis (88%+/-9%) and none having myocardial infarction or major adverse cardiac events during 30 days. Stress nuclear imaging results were negative in 72 (85%) patients, and multidetector CT results were negative in 73 (86%) patients. The sensitivity of stress nuclear imaging was 71% (95% confidence interval [CI] 36% to 92%), and multidetector CT was 86% (95% CI 49% to 97%), and the specificity was 90% (95% CI 81% to 95%) and 92% (95% CI 84% to 96%), respectively. The negative predictive value of stress nuclear imaging and multidetector CT was 97% (95% CI 90% to 99%) and 99% (95% CI 93% to 100%), respectively, and the positive predictive value was 38% (95% CI 18% to 64%) and 50% (95% CI 25% to 75%), respectively.

CONCLUSION

The accuracy of multidetector CT is at least as good as that of stress nuclear imaging for the detection and exclusion of an acute coronary syndrome in low-risk chest pain patients.

Usefulness of early exercise testing and clinical risk score for prognostic evaluation in chest pain units without preexisting evidence of myocardial ischemia

We investigated whether the result of early exercise testing yields prognostic information in addition to that afforded by a clinical risk score in patients who present with chest pain in the emergency department. The study group consisted of 340 patients without preexisting evidence of myocardial ischemia. A clinical risk score was calculated. Primary (mortality or myocardial infarction) and secondary (mortality, myocardial infarction, or rehospitalization due to unstable angina) end points at 1 year were defined. Patients with a positive exercise test result underwent invasive management. Frequencies of primary (7.4% vs 2.1%, p = 0.06) and secondary (9.3% vs 2.8%, p = 0.04) end points and risk score (1.6 +/- 1.0 vs 1.0 +/- 0.9 points, p = 0.0001) were higher in patients with a positive exercise test result. However, in multivariate analysis, clinical risk score was the only independent predictor for the primary (hazard ratio 2.0, 95% confidence interval 1.2 to 3.2, p = 0.004) and secondary (hazard ratio 1.9, 95% confidence interval 1.2 to 2.9, p = 0.003) end points. In conclusion, if a policy of invasive management is implemented for patients with positive exercise test results, the clinical risk score constitutes the main prognostic predictor of 1-year outcome.

Exercise testing in chest pain units: rationale, implementation, and results

Chest pain units are now established centers for assessment of low-risk patients presenting to the emergency department with symptoms suggestive of acute coronary syndrome. Accelerated diagnostic protocols, of which treadmill testing is a key component, have been developed within these units for efficient evaluation of these patients. Studies of the last decade have established the utility of early exercise testing,which has been safe, accurate, and cost-effective in this setting. Specific diagnostic protocols vary, but most require 6 to 12 hours of observation by serial electrocardiography and cardiac injury markers to exclude infarction and high-risk unstable angina before proceeding to exercise testing. However, in the chest pain unit at UC Davis Medical Center,the approach includes "immediate" treadmill testing without a traditional process to rule out myocardial infarction. Extensive experience has validated this approach in a large, heterogeneous population. The optimal strategy for evaluating low-risk patients presenting to the emergency department with chest pain will continue to evolve based on current research and the development of new methods.

A critical pathway for patients with acute chest pain and low risk for short-term adverse cardiac events: role of outpatient stress testing

STUDY OBJECTIVE

We evaluate the safety and feasibility of a critical care pathway protocol in which patients with acute chest pain who are low risk for coronary artery disease and short-term adverse cardiac outcomes receive outpatient stress testing within 72 hours of an emergency department (ED) visit.

METHODS

We performed an observational study of an ED-based chest pain critical pathway in an urban, community hospital in 979 consecutive patients. Patients enrolled in the protocol were observed in the ED before receiving 72-hour outpatient stress testing. The pathway was primarily analyzed for rates of death or myocardial infarction in the 6 months after ED discharge and outpatient stress testing. Secondary outcome measures included need for coronary intervention at initial stress testing and within 6 months after discharge, subsequent ED visits for chest pain, and subsequent hospitalization.

RESULTS

Of 871 stress-tested patients aged 40 years or older, who had low risk for coronary artery disease and short-term adverse cardiac events, and had 6-month follow-up, 18 (2%) required coronary intervention, 1 (0.1%) had a myocardial infarction within 1 month, 2 (0.2%) had a myocardial infarction within 6 months, 6 (0.7%) had normal stress test results after discharge but required cardiac catheterization within 6 months, and 5 (0.6%) returned to the ED within 6 months for ongoing chest pain. Hospital admission rates decreased significantly from 31.2% to 26.1% after initiation of the protocol (P<.001).

CONCLUSION

For patients with chest pain and low risk for short-term cardiac events, outpatient stress testing is feasible, safe, and associated with decreased hospital admission rates. With an evidence-based protocol, physicians efficiently identify patients at low risk for clinically significant coronary artery disease and short-term adverse cardiac outcomes.

Acute Myocardial Infarction Following a Negative Evaluation of Chest Pain

Although acute chest pain accounts for five million emergency room visits annually, only 10% represent acute myocardial infarctions (AMI). Even patients with negative evaluations of chest symptoms experience subsequent cardiac events. Patients readmitted with AMI within 90 days after a cardiac evaluation were examined to identify potential errors in management that may have Led to readmission. Only six of 2,340 patients met criteria for AMI after a negative work-up. No medical errors were found to account for the subsequent AMI. No other previously published reports have investigated the quality of chest pain evaluations to find missed opportunities for cardiac event prevention.

Assessment of patients with low-risk chest pain in the emergency department: Head-to-head comparison of exercise stress echocardiography and exercise myocardial SPECT

OBJECTIVES

The aim of the study was to compare head-to-head the performance of exercise tolerance test-stress echocardiography (ex-Echo) and exercise stress-perfusion nuclear imaging (exercise-single-photon emission computed tomography [ex-SPECT]) for the diagnosis of coronary artery disease (CAD) in patients evaluated at the chest pain unit with delay from chest pain (CP) onset.

BACKGROUND

As an early triage strategy for CAD in emergency medicine, ex-Echo could have the advantage of widespread availability and low costs.

METHODS

In the years 2000-2002, 503 consecutive patients (mean age 60 years) with recent (<24 hours) CP and nonischemic electrocardiogram (ECG), in whom CAD remained undiagnosed after first line 6-hour work-up including serum markers of myocardial injury and resting echocardiogram, underwent ex-Echo and ex-SPECT within 24 hours. Patients with (+)ex-Echo or (+)ex-SPECT or (+)ex-ECG or abnormal troponin I were referred to coronary angiography; otherwise, they were discharged and followed up. End points were coronary stenosis > or =50% and cardiovascular events at 6-month follow-up.

RESULTS

Ninety-nine patients (20%) had (+)ex-Echo and 121 (24%) (+)ex-SPECT; CAD was diagnosed in 81% and 67%, respectively; positive tests were concordant in 69%. In negative ex-Echo and ex-SPECT, final evidence of CAD emerged in 14 and 13, respectively. Ex-Echo demonstrated higher accuracy than ex-SPECT (93% +/- 1% vs 89% +/- 1%), optimal specificity (95% +/- 5% vs 90% +/- 5%), and positive predictive value (81% +/- 4% vs 67% +/- 4%); moreover, in the case of (-)ex-ECG, observed effective likelihood ratio indicates a (+)synergy between ex-ECG and ex-Echo.

CONCLUSIONS

Ex-Echo can be an effective diagnostic strategy in the early triage of CP patients, improving diagnosis in case of (-)ex-ECG and reducing unnecessary angiography number. Its drawback is represented by the 5% of missed diagnosis.

Only modest resources are needed to improve treatment of hospitalised patients with chest pain or heart failure: rapid assessment is a safe and efficient strategy

BACKGROUND

The objective of this study was to evaluate the safety and efficacy of rapid assessment using modest resources in hospitalised chest pain and heart failure patients.

METHODS

We evaluated 81 patients hospitalised for chest pain or heart failure in a prospective rapid assessment group and 162 patients in a retrospective usual care group with 6 months' follow-up. Main outcome measures were length of hospital stay at index observation, number of days spent in hospital for all causes, chest pain or heart failure, and number of visits to the doctor.

RESULTS

Chest pain patients: Length of hospital stay was significantly shorter in the rapid assessment group (1.3 vs. 3.7 days, P<0.0001). Days spent in hospital over 6 months were fewer in the rapid assessment group (2.9 vs. 8.8 days, P<0.005). Furthermore, the number of days spent in the hospital for chest pain or heart failure decreased (2.5 vs. 8.0 days, P<0.01). Heart failure patients: The length of hospital stay (8.7 vs. 9.7 days, P=ns) or days spent in the hospital over 6 months did not differ (25.7 vs. 23.1 days, P=ns). However, there were fewer days (10.5 vs. 16.7 days, P<0.01) spent in the hospital for chest pain or heart failure in the rapid assessment group.

CONCLUSIONS

Rapid assessment of hospitalised chest pain and heart failure patients on the next working day is a safe strategy in a medium-sized hospital. In 6 months, rapid assessment effectively reduces days spent in the hospital in chest pain patients, but not in heart failure patients. It can easily be integrated into standard care using modest resources.

Improving care in patients with acute coronary syndromes: the Erlanger quality improvement initiative

Quality improvement (QI) in emergency department (ED) patients with acute coronary syndromes (ACS) is a complex and dynamic phenomenon. ED physicians are faced with the challenge of multitasking a variety of patient complaints. This chaotic environment frequently hampers the ED physician's ability to properly evaluate and treat chest pain patients. Just as an airplane pilot would never take off without performing the comprehensive preflight operational checklist, the ED physician should have a standardized protocol for the evaluation and treatment of chest pain patients. In this report, we describe Erlanger Medical Center's 10-year QI initiative in developing a successful chest pain protocol for the rapid evaluation and treatment of patients with suspected ACS. Our initiative resulted from a collaborative effort among emergency physicians, cardiologists, nuclear radiologists, nursing staff, and administration. The systematic step-wise approach we utilized at our institution consisted of identification of the problem, development of standardized protocols, hospital-based QI initiatives, and continuation of QI efforts through national initiatives. Through this "building of bridges" among physicians, nursing, and administration, we hope that other institutions will modify our protocols to assist them in the development of their own successful QI program for improving the evaluation, treatment, and disposition of patients with suspected ACS.

Short-term risk after initial observation for chest pain

Few studies have evaluated the necessity of immediate stress testing after observation for chest pain. The purpose of this study was to assess the safety of outpatient stress testing after discharge from a chest pain unit. We hypothesized that discharge from a chest pain unit before stress testing is associated with a low rate of short-term adverse outcomes. This was a retrospective chart review of managed care patients discharged from the chest pain unit before the performance of stress testing. Records were reviewed for the occurrence of adverse cardiac outcomes before an outpatient stress test up to 60 days post-discharge. Primary outcomes were defined as death or myocardial infarction, and secondary outcomes as readmission for chest pain evaluation, unstable angina, or congestive heart failure. Three hundred forty-four patients were identified. One hundred sixty-six patients had either a recent prior stress test (17) or an outpatient test (149) performed within 60 days of discharge. During that time, 2 patients (0.6%) had a fatal out-of-hospital cardiac event, and there were 27 subsequent chest pain visits to the Emergency Department by 24 patients (7.0%). Nine patients (2.6%) were admitted to the hospital and 10 (2.9%) were readmitted to the observation unit for chest pain. We conclude that patients who have negative serial electrocardiograms and enzyme testing in a chest pain unit are at low risk for short-term cardiac events. Appropriately selected patients may be discharged for subsequent outpatient testing.

Implementation of myocardial perfusion imaging in the early triage of patients with suspected acute coronary syndromes

The risk of overlooking an underlying acute coronary syndrome remains an important challenge in patients complaining of chest pain but who have a non-diagnostic ECG (CP). Indeed, myocardial scintigraphy associated with exercise testing (exercise SPET) represents a valuable tool for excluding coronary artery disease (CAD) especially in patients with CP and delayed presentation to the emergency department. We sought to implement diagnoses of CAD in the early triage of CP patients by exercise gated SPET and compare diagnoses with outcomes. A total of 306 consecutive patients presenting with CP were found to be free of CAD at first line work-up including clinical evaluation, markers of myocardial injury and echocardiogram. These patients were studied initially with exercise SPET, and those with perfusion defects underwent angiography, while those with normal scans were discharged and followed up. Patients with positive scans (34%, n=105) had documented coronary stenoses in 43% (n=45); patients with negative scans (66%, n=201) had evidence of non-fatal coronary events at 6 months in 1.5% (n=3). When imaging was analysed with gating by the presence of transmural perfusion defects associated with wall motion abnormalities (n=86), only one patient, among 19 excluded, was recognized as having coronary stenosis by angiography (SPET vs gated SPET: negative predictive value 98.5% and 98%, respectively, P=NS; diagnostic accuracy 79% and 85%, respectively; P< or =0.03). Therefore, implementation of myocardial perfusion imaging in the early triage of patients with suspected acute coronary syndromes was effectively obtained by early exercise gated SPET, especially in patients with transmural myocardial perfusion defects associated with wall motion abnormalities.

The use and effectiveness of an emergency department observation unit for elderly patients

STUDY OBJECTIVE

Emergency department observation units are cost-effective alternatives to hospital admission for selected patients. However, the use and effectiveness of these units in the elderly population is unclear. We sought to describe the use of an ED observation unit by elderly patients (>or=65 years), to determine whether the ED observation unit is effective for them in terms of ED observation unit length of stay and hospital admission rates, and to compare efficacy and return visit rates between younger and older patients.

METHODS

This is a retrospective observational cohort study of consecutive adult patients sent to an ED observation unit from 1996 to 2000 at a high-volume tertiary care suburban teaching hospital. ED observation unit length of stay of less than 18 hours and admittance rates of less than 30% were used as indicators of efficacy. Diagnosis, length of stay, hospital admission rates, and 30-day return visit rates were compared between younger and older patients.

RESULTS

Twenty-two thousand five hundred and thirty adult patients were observed, with 37.2% older than 65 years of age. The most common diagnoses in elderly patients were chest pain (24.0%), dehydration (11.7%), syncope (6.5%), back pain (4.6%), and chronic obstructive pulmonary disease (3.8%). Length of stay in the ED observation unit was longer for the elderly than younger patients but still averaged less than 18 hours (15.8 hours [95% confidence interval (CI) 15.7 to 16.0] versus 14.4 hours [95% CI 14.3 to 14.5], respectively). Elderly patients were more likely to be admitted from the ED observation unit than younger patients (26.1% versus 18.5%); however, their overall admission rate remained less than 30%. Compared with younger patients, the odds ratios for inpatient admission of elderly patients was highest for back pain (2.10; 95% CI 1.62 to 2.73), pyelonephritis (1.78; 95% CI 1.16 to 2.71), and chest pain (1.65; 95% CI 1.44 to 1.89). Thirty-day related return visit rates between age groups were similar (9.4% versus 7.6%).

CONCLUSION

Elderly ED observation unit patients had ED observation unit lengths of stay and hospital admission rates that were effective for an ED observation unit setting and ED return visits rates that were comparable with those of younger patients.

The Erlanger chest pain evaluation protocol: a one-year experience with serial 12-lead ECG monitoring, two-hour delta serum marker measurements, and selective nuclear stress testing to identify and exclude acute coronary syndromes

STUDY OBJECTIVE

We determine the overall use of a 6-step accelerated chest pain protocol to identify and exclude acute coronary syndrome (ACS) and to confirm previous findings of the use of serial 12-lead ECG monitoring (SECG) in conjunction with 2-hour delta serum marker measurements to identify and exclude acute myocardial infarction (AMI).

METHODS

A prospective observational study was conducted over a 1-year period from January 1, 1999, through December 31, 1999, in 2,074 consecutive patients with chest pain who underwent our accelerated evaluation protocol, which includes 2-hour delta serum marker determinations in conjunction with automated SECG for the early identification and exclusion of AMI and selective nuclear stress testing for identification and exclusion of ACS. In patients not undergoing emergency reperfusion therapy, physician judgment was used to determine patient disposition at the completion of the 2-hour evaluation period: admit for ACS, discharge or admit for non-ACS condition, or immediate emergency department nuclear stress scan for possible ACS. A positive protocol was defined as a positive result in 1 or more of the 6 incremental steps in our chest pain evaluation protocol: (1) initial ECG diagnostic of acute injury or reciprocal injury; (2) baseline creatine kinase (CK)-MB level of 10 ng/mL or greater and index of 5% or greater or cardiac troponin I level of 2 ng/mL or greater; (3) new/evolving injury or new/evolving ischemia on SECG; (4) increase in CK-MB level of +1.5 ng/mL or greater or cardiac troponin I level of +0.2 ng/mL or greater in 2 hours; (5) clinical diagnosis of ACS despite a negative 2-hour evaluation; and (6) reversible perfusion defect on stress scan compared with on resting scan. All patients were followed up for 30-day ACS, which was defined as myocardial infarction (MI), percutaneous coronary intervention/coronary artery bypass grafting, coronary arteriography revealing stenosis of major coronary artery of 70% or greater not amenable to percutaneous coronary intervention/coronary artery bypass grafting, life-threatening complication, or cardiac death within 30 days of ED presentation.

RESULTS

Discharge diagnosis in the 2,074 study patients consisted of 179 (8.6%) patients with AMI, 26 (1.3%) patients with recent AMI (decreasing curve of CK-MB), and 327 (15.8%) patients with 30-day ACS. At 2 hours, sensitivity and specificity for MI (AMI or recent AMI) of SECG plus delta serum marker measurements was 93.2% and 93.9%, respectively (positive likelihood ratio 15.3; negative likelihood ratio 0.07). At the completion of the full ED evaluation protocol (positive result in >or=1 of the 6 incremental steps), sensitivity and specificity for 30-day ACS was 99.1% and 87.4%, respectively (positive likelihood ratio 7.9; negative likelihood ratio 0.01).

CONCLUSION

An accelerated chest pain evaluation strategy consisting of SECG, 2-hour delta serum marker measurements, and selective nuclear stress testing in conjunction with physician judgment identifies and excludes MI and 30-day ACS during the initial evaluation of patients with chest pain.

Effectiveness of a multidisciplinary chest pain unit for the assessment of coronary syndromes and risk stratification in the Florence area

BACKGROUND

In patients seen at the emergency department (ED) with chest pain (CP), noninvasive diagnostic strategies may differentiate patients at high or intermediate risk from those at low-risk for cardiovascular events and optimize the use of high-cost resources. However, in welfare healthcare systems, the feasibility, accuracy, and potential benefits of such management strategy need further investigation.

METHODS

A total of 13,762 consecutive patients with CP were screened, and their conditions were defined as high, intermediate, and low risk for short-term cardiovascular events. Patients at high and intermediate risk were admitted. Patients at low risk were discharged from the ED if first line (<6 hours, including electrocardiogram, troponins, and serum cardiac markers) or second line short-term evaluation (<24 hours, including echocardiogram, rest or stress 99m-Tc myocardial scintigraphy, exercise tolerance test, or stress-echocardiography) had negative results. Patients with a diagnosis of coronary artery disease (CAD) were admitted. Patients without evidence of cardiovascular disease underwent screening for psychiatric and gastroesophageal disorders. Inhospital mortality rate was assessed in all patients.

RESULTS

Among patients at high and intermediate risk (n = 9335), 2420 patients had acute myocardial infarction (26%, 10.6% mortality rate), 3764 had unstable angina (40%, 1.1% mortality rate), 129 had aortic dissection (1.4%, 23.3% mortality rate), and 408 had pulmonary embolism (4%, 27.6% mortality rate). The remaining 2614 had chronic coronary heart disease in the context of multiple pathology (n = 2256) or pleural or pericardial diseases (n = 358). Among patients at low risk (n = 4427), 2672 were discharged at <6 hours (60%, 0.2% incidence rate of nonfatal CAD at 6 months) and 870 patients were discharged at <24 hours (20%, no CAD at follow-up). The remaining 885 patients were recognized as having CAD (20%, 1.1% inhospital mortality rate). Finally, half of the patients without CAD had active gastroesophageal or anxiety disorders.

CONCLUSION

An effective screening program with an observation area inside the ED (1) could be implemented in a public healthcare environment and contribute significantly to the reduction of admissions, (2) could optimize the management of patients at high and intermediate risk and succeed in recognizing CAD in 20% of patients at low risk, and (3) could allow screening for alternative causes of CP in patients without evidence of CAD.

ROMEO: a rapid rule out strategy for low risk chest pain. Does it work in a UK emergency department?

AIMS

To examine the feasibility of using the ROMEO (rule out myocardial events on "obs" ward) pathway for low risk patients with chest pain in a UK emergency department.

METHODS

A prospective study was undertaken to determine outcomes for the first 100 patients entering the pathway (from May to Oct 1999). Serum troponin levels, serial ECG recordings, exercise test result, total length of stay, and final diagnoses were reviewed. Patients were telephoned after discharge to inquire about persisting or recurrent pain, and further investigations after completing the ROMEO pathway.

RESULTS

82 of 100 (82%) had myocardial damage excluded by serum troponin assay. Sixty two of 82 (76%) of these completed exercise tolerance testing (ETT). Fifty seven of 62 (92%) ETTs were negative. Twenty of 82 (26%) did not undergo ETT because of mobility problems, recent ETT, or if considered very low probability of cardiac pain on consultant review. Five of 100 (5%) had an increased initial troponin and five of 100 (5%) had an increased 12 hour troponin. These patients were referred for admission under the general physicians. Seven of 100 (7%) were referred for other reasons (late ECG changes, continuing or worsening pain). One patient self discharged. Length of stay varied because of changes to arrangements for ETT. The median time for all patients over the period studied was 23 hours. All patients were discharged within an hour of a negative ETT. FOLLOW UP RESULTS: 67 of 74 (91%) eligible patients were contacted by telephone. Forty six of 67 (69%) had no further pain, attendances, or GP consultations. Six of 67 (9%) had further cardiological investigation or treatment.

CONCLUSIONS

A rapid rule out strategy such as the ROMEO pathway is feasible in the UK healthcare setting and provides standardised and consistent evaluation.

Critical pathways for patients with acute chest pain at low risk

Critical pathways are predefined protocols that define the crucial steps in evaluating and treating a clinical problem to improve quality of patient care, reduce variability and enhance efficiency. Critical pathways have proliferated for a variety of diagnoses, including evaluation of patients with chest pain, a common and costly complaint. This review will outline the development, implementation, and assessment of critical pathways using as a paradigm our experience with a pathway for patients presenting to the Emergency Department with acute chest pain who are at low risk of myocardial ischemia. The goals of the pathway were to expedite evaluation of low-risk patients and reduce admission rates among these patients and in the cohort overall without compromising outcomes. The pathway was developed by a multidisciplinary team in an iterative process that considered published literature, as well as the experience and consensus of local opinion leaders. Patients at least 30 years old presenting to the Emergency Department of an urban teaching hospital who were pain-free without heart failure or ischemic changes on EKG, but who were not considered appropriate for discharge by the treating physician, were eligible for the critical pathway. The pathway involved one set of creatine kinase-MB enzymes drawn at least 4 hours after pain, a 6 hour observation period after the last episode of pain and exercise testing. Outcomes during evaluation and admission rates were assessed. Clinical outcomes at 7 days and 6 months after evaluation and patient satisfaction at 7 days were also measured. Of 1363 patient visits, 145 (10.6%) were triaged by the pathway: 131 (90.3%) were discharged, 14 (9.7%) were admitted. The overall admission rate decreased from 63% (2898/4595) to 60% (819/1363) [p < 0.05] in comparison to a cohort studied prior to pathway implementation. Pathway patients reported low rates of subsequent cardiac procedures. No deaths or myocardial infarctions were recorded. At 7 days, only 2 respondents (2%) reported going to an Emergency Department since their evaluation. Most respondents (83%) rated their care as very good or excellent. Critical pathways designed to enhance efficiency, reduce variability, and improve the quality of care are becoming increasingly common. Our pathway for evaluation of patients with chest pain at low risk of myocardial ischemia was feasible and safe and was associated with a decline in absolute admission rates. Because of the possibility of concomitant secular trends and the effects of a changing medical environment, further rigorous research on the efficacy of individual pathways is needed.

Chest pain unit management of patients at low and not low-risk for coronary artery disease in the emergency department. A 5-year experience in the Florence area

In this study, we screened a total of 6723 consecutive patients with chest pain and ECG non-diagnostic for acute myocardial infarction (AMI) on presentation to the emergency department (ED). The aim of the study was to avoid missed AMI, improve safe early discharge and reduce inappropriate coronary care unit (CCU) admission. Chest pain patients were triaged using a clinical chest pain score and managed in a chest pain unit (CPU). Patients with a low clinical chest pain score were considered at very 'low-risk' for cardiovascular events and discharged from the ED; patients with a high chest pain score were submitted to CPU management. Observation and titration of serum markers of myocardial injury were obtained up to 6 hours. Rest or stress myocardial scintigraphy (SPECT) was performed in patients > 40 years or with > or = 2 major coronary risk factors. Exercise Tolerance Test (ETT) or Stress-Echocardiogram (stress-Echo) were performed in younger patients or with < 2 coronary risk factor, or unable to exercise, respectively We discharged directly from the ED the majority of patients (4454; 66%): in this group there was only a 0.2% final diagnosis of coronary artery disease (CAD) at follow-up. The remaining 34% of patients, with non-diagnostic or normal ECG, were managed in the CPU. In this group, 1487 patients (representing 22% of the overall study group) were found positive for CAD, two-thirds because of delayed ECG or serum markers of myocardial injury, and one-third by Echo, SPECT or ETT. In conclusion, CPU based management allowed 22% early detection of myocardial ischaemia and 78% early discharge from the ED avoiding inappropriate CCU admission and optimizing the use of urgent angiography.

Selective dual nuclear scanning in low-risk patients with chest pain to reliably identify and exclude acute coronary syndromes

STUDY OBJECTIVE

We sought to determine the use in routine clinical practice of selective dual nuclear cardiac scanning (rest and stress) in low-risk patients with chest pain for identifying and excluding acute coronary syndromes (ACSs) during the initial emergency department evaluation.

METHODS

A prospective observational study was conducted over 13 months in 1,775 low-risk patients with chest pain who had intermediate- and high-risk ACSs ruled out by means of our 2-hour protocol, which consists of automated serial 12-lead ECG monitoring in conjunction with baseline and 2-hour creatine kinase (CK) MB and troponin I (cTnI) measurements. At the completion of the 2-hour evaluation period, low-risk patients were stratified by means of physician judgment into 1 of 2 categories: category III, possible ACS; and category IV, probable non-ACS chest pain. Level III patients underwent immediate dual nuclear scanning (rest thallium and stress sestamibi scanning), and level IV patients were discharged directly from the ED unless another serious non-ACS medical condition was thought to exist. Rest and stress scans were interpreted by a board-certified radiologist contemporaneous with patient evaluation. All patients were followed up for 30-day ACS, which was defined as acute myocardial infarction, percutaneous transluminal coronary angioplasty/coronary artery bypass grafting, coronary arteriography revealing stenosis of the major coronary artery of 70% or greater not amenable to percutaneous transluminal coronary angioplasty/coronary artery bypass grafting, life-threatening complication, or cardiac death within 30 days of ED presentation.

RESULTS

A total of 2,206 ED patients with chest pain were evaluated for ACS during the study period. Four hundred thirty-one patients were excluded for having 1 or more of the following findings: initial ECG diagnostic of injury; baseline CK-MB level, cTnI level, or both diagnostic of acute myocardial infarction; 2-hour DeltaCK-MB level of +1.5 ng/mL or greater; 2-hour DeltacTnI level of +0.2 ng/mL or greater; injury or new or evolving ischemia on serial 12-lead ECG monitoring; or clinical diagnosis of ACS. Of the 1,775 study patients, 805 (45.4%) underwent immediate dual nuclear scanning. A positive stress nuclear scan result was more sensitive (97.3% versus 71.2%, P <.0001) and specific (87.7% versus 72.6%, P <.0001) for 30-day ACS than a positive resting nuclear scan result. The protocol of selective dual nuclear scanning (ie, patients who did not undergo dual nuclear scanning were counted as having a negative test result) had a sensitivity and specificity for 30-day ACS of 93.4% and 94.7%, respectively (positive likelihood ratio 17.6; negative likelihood ratio 0.07).

CONCLUSION

Stress nuclear scanning is more sensitive and specific than resting nuclear scanning for identification of ACS in low-risk patients with chest pain. A strategy of using selective dual nuclear scanning once high- and intermediate-risk ACS has been ruled out with our 2-hour evaluation both reliably identifies and reliably excludes 30-day ACS.

Randomized comparison of a strategy of predischarge coronary angiography versus exercise testing in low-risk patients in a chest pain unit: in-hospital and long-term outcomes

OBJECTIVES

This randomized trial compared a strategy of predischarge coronary angiography (CA) with exercise treadmill testing (ETT) in low-risk patients in the chest pain unit (CPU) to reduce repeat emergency department (ED) visits and to identify additional coronary artery disease (CAD).

BACKGROUND

Patients with chest pain and normal electrocardiograms (ECGs) have a low likelihood of CAD and a favorable prognosis, but they often seek repeat evaluations in EDs. Remaining uncertainty regarding their symptoms and diagnosis may cause much of this recidivism.

METHODS

A total of 248 patients with no ischemic ECG changes triaged to a CPU were randomized to CA (n = 123) or ETT (n = 125). All patients had a probability of myocardial infarction < or =7% according to the Goldman algorithm, no biochemical evidence of infarction, the ability to exercise and no previous documented CAD. Patients were followed up for > or =1 year and surveyed regarding their chest pain self-perception and utility of the index evaluation.

RESULTS

Coronary angiography showed disease (> or =50% stenosis) in 19% and ETT was positive in 7% of the patients (p = 0.01). During follow-up (374+/-61 days), patients with a negative CA had fewer returns to the ED (10% vs. 30%, p = 0.0008) and hospital admissions (3% vs. 16%, p = 0.003), compared with patients with a negative/nondiagnostic ETT. The latter group was more likely to consider their pain as cardiac-related (15% vs. 7%), to be unsure about its etiology (38% vs. 26%) and to judge their evaluation as not useful (39% vs. 15%) (p < 0.01 for all comparisons).

CONCLUSIONS

In low-risk patients in the CPU, a strategy of CA detects more CAD than ETT, reduces long-term ED and hospital utilization and yields better patient satisfaction and understanding of their condition.

Exercise testing in special situations: ER, preoperative and disability evaluation

In a number of medical centers, exercise testing has proven to be a safe and useful tool in the evaluation of patients presenting chest pain in an emergency room. At these centers, after a period of observation without evidence of acute myocardial infarction, exercise testing is done. If the exercise test result is normal, the patient is discharged from the emergency room, without being admitted to the hospital. Exercise testing is a well-accepted noninvasive method to evaluate at-risk patients being considered for elective noncardiac surgery. Exercise testing is frequently used to determine functional capacity during disability assessment.

Stress testing for risk stratification of patients with low to moderate probability of acute cardiac ischemia

In summary, this article focused on the use of stress testing to risk-stratify patients at the conclusion of their emergency evaluation for ACI. As discussed, those patients in the probably not ACI category require additional risk stratification prior to discharge. It should be kept in mind that patients in this category are heterogeneous, containing subgroups at both higher and lower risk of ACI and cardiac events. The patients with lower pretest probability for ACI may only need exercise testing in the ED. Patients with higher pretest probability should undergo myocardial perfusion or echocardiographic stress testing to maximize diagnostic and prognostic information. Prognostic information is the key to provocative testing in the ED. Prognostic information is the component that will help emergency physicians identify the patients who may be discharged home safely without having to worry about a 6% annual cardiac death rate and a 10% overall death rate over the next 30 months. Stress testing provides this key prognostic data, and it can be obtained in short-stay chest pain observation units in a safe, timely, and cost-effective fashion.