A critical pathway for management of patients with acute chest pain who are at low risk for myocardial ischemia: recommendations and potential impact

Implementation of a chest pain management service improves patient care and reduces length of stay

OBJECTIVE

Chest pain is one of the most common complaints in patients presenting to an emergency department. Delays in management due to a lack of readily available objective tests to risk stratify patients with possible acute coronary syndromes can lead to an unnecessarily lengthy admission placing pressure on hospital beds or inappropriate discharge. The need for a co-ordinated system of clinical management based on enhanced communication between departments, timely and appropriate triage, clinical investigation, diagnosis, and treatment was identified.

METHODS

An evidence-based Chest Pain Management Service and clinical pathway were developed and implemented, including the introduction of after-hours exercise stress testing.

RESULTS

Between November 2005 and March 2013, 5662 patients were managed according to a Chest Pain Management pathway resulting in a reduction of 5181 admission nights by more timely identification of patients at low risk who could then be discharged. In addition, 1360 days were avoided in high-risk patients who received earlier diagnosis and treatment.

CONCLUSIONS

The creation of a Chest Pain Management pathway and the extended exercise stress testing service resulted in earlier discharge for low-risk patients; and timely treatment for patients with positive and equivocal exercise stress test results. This service demonstrated a significant saving in overnight admissions.

Cost burden of non-specific chest pain admissions

BACKGROUND

Non-cardiac aetiologies are common among patients presenting with chest pain.

AIM

To determine the cost of non-specific chest pain admissions to a tertiary referral, teaching hospital.

METHODS

Thrombolysis in myocardial infarction risk (TIMI) risk score, lengths of stay (LOS), investigations and diagnoses were recorded for patients admitted with chest pain. Non-specific chest pain was defined as chest pain where cardiac, pulmonary and gastroesophageal aetiologies were excluded. Costs of admissions were calculated.

RESULTS

Of 80 patients, 34 (4%) and 22 (28%) were diagnosed with non-specific chest pain and acute coronary syndrome, respectively. Non-specific chest pain admissions had a mean age of 54 (11; 35-74) years, LOS of 3.8 (2.6; 1-11) days and TIMI risk score of 1.4 (1.5; 0-5). Acute coronary syndrome admissions had a mean age of 67 (14; 43-94) years, LOS of 7.7 (4.3; 2-16) days and TIMI risk score of 3.1 (1.2; 0-5). The mean cost per non-specific chest pain admission was €3,729 (2,378; 1,034-10,468), or 48% of the mean cost per acute coronary syndrome admission of €7,667 (4,279; 1,963-16,071). Bed day costs account for >90% of overall costs. Only 7% of patients were weekend discharges. The mean interval to exercise stress test was 2.7(1.5; 1-7) days.

CONCLUSIONS

The mean costs of admission and LOS for patients with non-specific chest pain are significant. Extrapolating findings, annual national cost is estimated at approximately €71 million for this cohort, with 73,000 bed days consumed nationally. Delays from admission to tests and low percentage of weekend discharges prolong LOS.

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.

Prospective evaluation of a clinical guideline recommending early patients discharge in bleeding peptic ulcer

BACKGROUND AND AIM

To validate an early discharge policy in patients admitted with upper gastrointestinal bleeding (UGIB) due to ulcers.

METHODS

Patients with gastroduodenal ulcer or erosive gastritis/duodenitis were included in a previous study aiming to develop a practice guideline for early discharge of patients with UGIB. Variables associated with unfavorable evolution were analyzed in order to identify patients with low-risk of re-bleeding. After that, a one-year prospective analysis of all UGIB episodes was carried out.

RESULTS

A total of 341 patients were identified in the retrospective study. Variables associated with unfavorable evolution were: systolic blood pressure < or = 100 mmHg, heart rate > or = 100 bpm, and a Forrest endoscopic classification of severe. 10% of patients were immediately discharged; however, if predictive variables obtained in the multivariate analysis had been used, hospitalization could have been prevented in 34% of patients. A total of 77 patients were included in the prospective analysis. Although only 19.5% of patients were immediately discharged without complications, 29 patients (37.7%) were theoretically suitable for early discharge.

CONCLUSIONS

Patients with UGIB who have clean-based ulcers and are stable on admission can be safely discharged immediately after endoscopy. Implementation of the clinical practice guideline safely reduced hospital admission for those patients.

Design of a comprehensive chest pain initiative in an academic urban hospital

We describe the development and institution of an initiative based on a clinical diagnostic algorithm and treatment pathways, facilitated by cardiac nurse practitioners, for the treatment of the diverse group of patients with chest pain who seek treatment at our urban-based institution. We believe that our chest pain initiative incorporates previous strategies of rapid emergency department management with inpatient-based care while providing a framework for outpatient follow-up and secondary prevention. These strategies allow our hospital to meet its goals of providing chest pain patients with standardized, high-quality, and expeditious care, given the challenges faced by an academic urban hospital.

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.

Exercise tolerance as a predictor of acute myocardial infarction in emergency department patients with potential acute coronary syndromes

There is mounting evidence that exercise tolerance is an important predictor of heart disease. Our objective was to determine if decreased exercise tolerance, as estimated by physicians, may be useful in stratifying risk in Emergency Department (ED) patients with potential acute coronary syndromes. We conducted a prospective cohort study on a convenience sample of ED patients at an urban teaching hospital. Patients with chest pain, dyspnea, syncope, or epigastric pain who were evaluated for acute coronary syndromes were included. Clinical and laboratory data were recorded. In addition, the Emergency Physicians were asked to estimate the exercise tolerance of the patient as excellent, good, bad, or very poor. The primary outcome of the study was myocardial infarction (MI) or death in patients stratified by physician-perceived exercise tolerance (excellent or good vs. bad or very poor). There were 166 patients enrolled in the study. Nine patients (5%) had an MI; there were no deaths. Physicians reported exercise tolerance as excellent in 33 patients, good in 63, bad in 50, and very poor in 20. The unadjusted risk of MI was significantly elevated in patients with physician-perceived decreased exercise tolerance (relative risk = 4.8, 95% confidence interval 1.03-22). After adjustment for age, sex, and major cardiovascular risk factors, decreased exercise tolerance remained a significant predictor of MI (adjusted odds ratio = 7.3, 95% confidence interval 1.2-46). Exercise tolerance, as estimated by clinical impression, may be an important predictor of complications in ED patients presenting with potential acute coronary syndromes.

Diagnostic uncertainty and costs associated with current emergency department evaluation of low risk chest pain

INTRODUCTION

Of all stress tests done in low risk Emergency Department observation units (OU), a small, but significant number may be reported as positive or indeterminate. The objective of this study is to quantify the prevalence and costs associated with positive and indeterminate stress tests that result in negative cardiac catheterization.

METHODS

Retrospective observational cohort study over 9 months. All patients undergoing the chest pain protocol who got cardiac stress testing in the OU were eligible for inclusion. Cost data were derived from an institutional activity-based cost system utilizing actual costs. Chart review was completed on all patients with positive and indeterminate stress tests and a randomly chosen sample of those with negative stress tests.

RESULTS

Of the 1194 patients who met the inclusion criteria, 1084 (90.8%) had a negative stress test. Sixty-two (5.2%) had a positive stress test, and 48 (4.0%) had an indeterminate stress test. Of all 59 patients who underwent catheterization, 41 (69.5%) were negative cardiac catheterizations. The prevalence among all OU stress test patients of positive or indeterminate stress tests with subsequent negative cardiac catheterization was 41/1194 (3.4%; 95% CI 2.5%-4.6%). The prevalence of significant coronary artery disease at cardiac catheterization was 18/1194 (1.5%; 95% CI 1.0%-2.4%). Patients with a positive or indeterminate stress test who had a negative catheterization incurred increased OU costs ($1385 vs. $1,039, P = 0.012), total costs ($7298 vs. $1562, P < 0.001) and length of inpatient stay (1.83 days vs. 0.00 days) when compared with those who had a negative stress test.

CONCLUSION

The probability of going to the OU and having a positive or indeterminate stress test resulting in a subsequent negative catheterization was double the probability of having a stress test result in catheterization that detected significant coronary artery disease. These patients incurred 5 times the total cost when compared with those patients with negative stress testing. Further investigation is warranted to determine alternative risk stratification methods for these low risk chest pain patients with positive stress tests.

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.

Automatic covariate selection in logistic models for chest pain diagnosis: a new approach

A newly established method for optimizing logistic models via a minorization-majorization procedure is applied to the problem of diagnosing acute coronary syndromes (ACS). The method provides a principled approach to the selection of covariates which would otherwise require the use of a suboptimal method owing to the size of the covariate set. A strategy for building models is proposed and two models optimized for performance and for simplicity are derived via 10-fold cross-validation. These models confirm that a relatively small set of covariates including clinical and electrocardiographic features can be used successfully in this task. The performance of the models is comparable with previously published models using less principled selection methods. The models prove to be portable when tested on data gathered from three other sites. Whilst diagnostic accuracy and calibration diminishes slightly for these new settings, it remains satisfactory overall. The prospect of building predictive models that are as simple as possible for a required level of performance is valuable if data-driven decision aids are to gain wide acceptance in the clinical situation owing to the need to minimize the time taken to gather and enter data at the bedside.

Are the outcomes of clinical pathways evidence-based? A critical appraisal of clinical pathway evaluation research

AIM AND OBJECTIVE

To evaluate the validity of study outcomes of published papers that report the effects of clinical pathways (CP).

METHOD

Systematic review based on two search strategies, including searching Medline, CINAHL, Embase, Psychinfo and Picarta from 1995 till 2005 and ISI Web of Knowledge SM. We included randomized controlled or quasi-experimental studies evaluating the efficacy of clinical pathway application. Assessment of the methodological quality of the studies included randomization, power analysis, selection bias, validity of outcome indicators, appropriateness of statistical tests, direct (matching) and indirect (statistical) control for confounders. Outcomes included length of stay, costs, readmission rate and complications. Two reviewers independently assessed the methodological quality of the selected papers and recorded the findings with an evaluation tool developed from a set of items for quality assessment derived from the Cochrane Library and other publications.

RESULTS

The study sample comprised of 115 publications. A total of 91.3% of the studies comprised of retrospective studies and 8.7% were randomized controlled studies. Using a quality-scoring assessment tool, 33% of the papers were classified as of good quality, whereas 67% were classified as of low quality. Of the studies, 10.4% controlled for confounding by matching and 59.1% adopted parametric statistical tests without testing variables on normal distribution. Differences in outcomes were not always statistically tested.

CONCLUSION

Readers should be cautious when interpreting the results of clinical pathway evaluation studies because of the confounding factors and sources of contamination affecting the evidence-based validity of the outcomes.

Mitral regurgitation: determinants of referral for cardiac surgery by Canadian cardiologists

PURPOSE

Advances in surgery permit for earlier intervention with improved outcomes for patients with mitral regurgitation (MR). Many patients still appear to be referred to surgery late in their course. Consensus guidelines were compared with the surgical referral practices for MR among Canadian cardiologists.

METHODS

A self-administered questionnaire was mailed to all adult cardiologists in Canada. This included seven case scenarios, as well as direct questions designed to establish the influence of factors including atrial fibrillation, pulmonary hypertension, left ventricular (LV) dilation, experience of the cardiac surgeon, symptoms and ejection fraction (EF) on referral.

RESULTS

There were 319 respondents; LVEF was rated as extremely important in 71.5% of patients and moderately important in 26% of patients. In asymptomatic patients, EF of 50% to 60% was correctly identified as a trigger for surgery by 57.2 % of cardiologists, while only 15.6% of cardiologists correctly referred New York Heart Association class II patients with normal LV function. The group complied in only 4.77 of the seven case scenarios. Compliance was inversely related to years in practice for asymptomatic patients with mild LV dysfunction, as well as in overall compliance. Referral practices were similar among clinicians, echocardiographers, interventional cardiologists and researchers, with no differences in geographic region or academic affiliation.

CONCLUSION

Compliance with published guidelines for patients with MR and either New York Heart Association class II or mild LV dysfunction among Canadian cardiologists was poor. Compliance was somewhat better in more recent graduates, suggesting the need to institute programs geared at enhancing knowledge of published standards and introduce practical tools to aid in their implementation.

Clinical risk scoring beyond initial troponin values: results from a large, prospective, unselected acute chest pain population

BACKGROUND

Risk stratifying the diverse group of patients who present to hospital with chest discomfort remains challenging. Current clinical risk models, typically derived from selected populations, are limited by their relative complexity and the absence of a well-defined role of troponin.

OBJECTIVE

To derive a simple clinical risk score from a large, unselected population of patients with chest discomfort and to delineate the prognostic value of an initial troponin measurement.

METHODS

Prospective, consecutive data were collected from patients who presented to a tertiary care hospital. Multivariate analysis was used to identify variables predictive of the primary end point: death, nonfatal myocardial infarction or revascularization at 30 days. Integer values were assigned, generating a risk score to quantify individual patient risk.

RESULTS

Among 1054 patients, predictor variables included ST-segment deviation (strongest predictor -- assigned two points), male sex, prior congestive heart failure, three or more cardiac risk factors and prior acetylsalicylic acid use (one point each). There was a progressive increase in events with increasing total score (P<0.0001), with a 15-fold gradient from scores of 0 to 4 and greater. Although a negative troponin measurement was associated with fewer events for all scores, patients with higher scores remained exposed to substantial risk. A negative initial troponin measurement conferred a negative predictive value of 97.3% (95% CI 93.7% to 99.1%) among patients with a risk score of 0.

CONCLUSION

Significant 30-day events occurred in patients with elevated risk scores, despite negative initial troponin measurements, emphasizing the importance of clinical risk stratification. This simple clinical risk score, in conjunction with a single troponin I measurement, facilitates triage of patients who present to hospital with chest discomfort.

Adverse events following an emergency department visit

BACKGROUND

Many studies demonstrate a high rate of treatment-related adverse outcomes or adverse events. No studies have prospectively evaluated adverse events in patients discharged home from the emergency department (ED).

OBJECTIVE

To describe the types of adverse events in patients discharged home from an ED.

PATIENTS

PATIENTS who were sent home directly from the ED of an urban, academic teaching hospital in Ottawa, Canada.

METHODS

Patient records were reviewed to identify demographic and medical history information. Two weeks following the ED visit, patients completed a standard telephone interview to record post ED visit outcomes. Two physicians reviewed outcomes to identify all adverse events and their cause.

RESULTS

Follow-up was complete for 399 of 408 enrolled patients. The median age was 49 years (interquartile range 36-68) and 50% were male. The most common diagnosis was "chest pain", occurring in 74 patients (18%), followed by "bone and joint disorders" in 55 patients (14%). 24 patients experienced an adverse event (incidence 6% (95% CI 4% to 9%)), of which 17 were preventable (incidence 4% (95% CI 3% to 7%)). Five of the unpreventable adverse events were medication side effects and two were minor, procedure-related complications. Of all 24 adverse events, 15 (63%; 95% CI 43 to 79%) led to an additional ED visit or a hospitalisation. Preventable adverse events occurred in 5 of 78 chest pain patients (incidence 6% (95% CI 3% to 14%)).

CONCLUSION

Most adverse events occurring following an ED visit are preventable and often relate to diagnostic or management errors.

Using a clinical pathway and education to reduce inappropriate prescribing of enoxaparin in patients with acute coronary syndromes: a controlled study

AIMS

To evaluate efficacy of a pathway-based quality improvement intervention on appropriate prescribing of the low molecular weight heparin, enoxaparin, in patients with varying risk categories of acute coronary syndrome (ACS).

METHODS

Rates of enoxaparin use retrospectively evaluated before and after pathway implementation at an intervention hospital were compared to concurrent control patients at a control hospital; both were community hospitals in south-east Queensland. The study population was a group of randomly selected patients (n = 439) admitted to study hospitals with a discharge diagnosis of chest pain, angina, or myocardial infarction, and stratified into high, intermediate, low-risk ACS or non-cardiac chest pain: 146 intervention patients (September-November 2003), 147 historical controls (August-December 2001) at the intervention hospital; 146 concurrent controls (September-November 2003) at the control hospital. Interventions were active implementation of a user-modified clinical pathway coupled with an iterative education programme to medical staff versus passive distribution of a similar pathway without user modification or targeted education. Outcome measures were rates of appropriate enoxaparin use in high-risk ACS patients and rates of inappropriate use in intermediate and low-risk patients.

RESULTS

Appropriate use of enoxaparin in high-risk ACS patients was above 90% in all patient groups. Inappropriate use of enoxaparin was significantly reduced as a result of pathway use in intermediate risk (9% intervention patients vs 75% historical controls vs 45% concurrent controls) and low-risk patients (9% vs 62% vs 41%; P < 0.001 for all comparisons). Pathway use was associated with a 3.5-fold (95% CI: 1.3-9.1; P = 0.012) increase in appropriate use of enoxaparin across all patient groups.

CONCLUSION

Active implementation of an acute chest pain pathway combined with continuous education reduced inappropriate use of enoxaparin in patients presenting with intermediate or low-risk ACS.

Utility of admission cardiac troponin and "Ischemia Modified Albumin" measurements for rapid evaluation and rule out of suspected acute myocardial infarction in the emergency department

OBJECTIVE

To assess if the combination of cardiac troponin (cTn) and Ischemia Modified Albumin (IMA) can be used for early exclusion of acute myocardial infarction (AMI).

METHODS

Prospective consecutive admissions to the emergency department (ED) with undifferentiated chest pain were assessed clinically and by electrocardiography. A total of 539 patients (335 men, 204 women; median age 51.9 years) considered at low risk of AMI had blood drawn on admission. If the first sample was less than 12 hours from onset of chest pain, a second sample was drawn two hours later, at least six hours from onset of chest pain. Creatine kinase MB isoenzyme (CKMB) mass was measured on the first sample and CKMB mass and cTnT on the second sample. An aliquot from the first available sample was frozen and subsequently analysed for IMA. If cTnT had not been measured on the original sample cTnI was measured (n = 189).

RESULTS

Complete data were available for 538/539 patients. IMA or cTn was elevated in the admission sample of all patients with a final diagnosis of AMI (n = 37) with IMA alone elevated in 2/37, cTn alone in 19/37, and both in 16/37. In 173/501 patients in whom AMI was excluded both tests were negative. In the non-AMI group 22 patients had elevation of both IMA and cTn in the initial sample, suggesting ischaemic disease.

CONCLUSION

Admission measurement of cardiac troponin plus IMA can be used for early classification of patients presenting to the ED to assist in patient triage.

Chest pain unit concept: rationale and diagnostic strategies

Each year in the United States, over 8 million patients present to the emergency department(ED) with complaints of chest discomfort or other symptoms consistent with possible acute coronary syndrome (ACS). While over half of these patients are typically admitted for further diagnostic evaluation, fewer than 20% are diagnosed with ACS. With hospital beds and inpatient resources scarce, these admissions can be avoided by evaluating low- to moderate-risk patients in chest pain units. This large, undifferentiated patient population represents a potential high-risk group for emergency physicians requiring a systematic approach and specific ED resources. This evaluation is required to appropriately determine if a patient is safe to be discharged home with outpatient follow-up versus requiring admission to the hospital for monitoring and further testing.

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.

Pretest probability assessment derived from attribute matching

Background

Pretest probability (PTP) assessment plays a central role in diagnosis. This report compares a novel attribute-matching method to generate a PTP for acute coronary syndrome (ACS). We compare the new method with a validated logistic regression equation (LRE).

Methods

Eight clinical variables (attributes) were chosen by classification and regression tree analysis of a prospectively collected reference database of 14,796 emergency department (ED) patients evaluated for possible ACS. For attribute matching, a computer program identifies patients within the database who have the exact profile defined by clinician input of the eight attributes. The novel method was compared with the LRE for ability to produce PTP estimation <2% in a validation set of 8,120 patients evaluated for possible ACS and did not have ST segment elevation on ECG. 1,061 patients were excluded prior to validation analysis because of ST-segment elevation (713), missing data (77) or being lost to follow-up (271).

Results

In the validation set, attribute matching produced 267 unique PTP estimates [median PTP value 6%, 1^st–3^rd quartile 1–10%] compared with the LRE, which produced 96 unique PTP estimates [median 24%, 1^st–3^rd quartile 10–30%]. The areas under the receiver operating characteristic curves were 0.74 (95% CI 0.65 to 0.82) for the attribute matching curve and 0.68 (95% CI 0.62 to 0.77) for LRE.

The attribute matching system categorized 1,670 (24%, 95% CI = 23–25%) patients as having a PTP < 2.0%; 28 developed ACS (1.7% 95% CI = 1.1–2.4%). The LRE categorized 244 (4%, 95% CI = 3–4%) with PTP < 2.0%; four developed ACS (1.6%, 95% CI = 0.4–4.1%).

Conclusion

Attribute matching estimated a very low PTP for ACS in a significantly larger proportion of ED patients compared with a validated LRE.

Identification of patients with evolving coronary syndromes by using statistical models with data from the time of presentation

OBJECTIVE

To derive statistical models for the diagnosis of acute coronary syndromes by using clinical and ECG information at presentation and to assess performance, portability, and calibration of these models, as well as how they may be used with cardiac marker proteins.

DESIGN AND METHODS

Data from 3462 patients in four UK teaching hospitals were used. Inputs for 8, 14, 25, and 43 factor logistic regression models were selected by using log10 likelihood ratios (log10 LRs). Performance was analysed by receiver operating characteristic curves.

RESULTS

A 25 factor model derived from 1253 patients from one centre was selected for further study. On training data, 98.2% of ST elevation myocardial infarctions (STEMIs) and 96.2% of non-ST elevation myocardial infarctions (non-STEMIs) were correctly classified, whereas only 2.1% of non-cardiac cases were incorrectly classified. On data from three other centres, 97.3% of STEMIs and 91.9% of non-STEMIs were correctly classified. Differences in log10 LRs for individual inputs from different centres accounted for the decline in performance when models were applied to unseen data. Classification was improved when output was combined with either clinical opinion or marker proteins.

CONCLUSIONS

Logistic regression models based on data available at presentation can classify patients with chest pain with a high degree of accuracy, particularly when combined with clinical opinion or marker proteins.

Positive impact of an interdisciplinary chest pain initiative on traditionally underserved populations

BACKGROUND

We assessed the clinical impact of an interdisciplinary, cardiac nurse practitioner-facilitated chest pain (CP) initiative that stresses an early invasive approach for patients with CP with acute coronary syndromes in traditionally underserved patient populations, including females, blacks, Hispanics, and patients older than 60 years.

METHODS

Two groups of patients were identified: Pre-CP initiative (December 1999-February 2000) and post-CP initiative (December 2000-February 2001).

RESULTS

Analysis of 714 patients revealed significantly more cardiac diagnoses post-CP initiative (61% pre-CP initiative vs. 73% post-CP initiative, P = 0.002), including in patients with myocardial infarction (MI) who were older than 60 years, females, and Hispanics. There was a significant increase in rates of cardiac catheterizations within 1 week of admission (10.5% vs. 20.4%, P <0.001), including in Hispanics. For rates of coronary artery stenting and/or bypass grafting (CABG), there was also a significant increase post-CP initiative (2.5% vs. 10.1%, P = 0.0005), as well as for Hispanics. Length of stay was significantly reduced for patients older than 60 years (8.3 vs. 5.8 days, P = 0.002).

CONCLUSION

Establishment of an interdisciplinary, cardiac nurse practitioner-facilitated CP initiative is associated with improvement in several clinical processes and outcomes: increased cardiac disease diagnosis in females, Hispanics, and patients older than 60 years; increased rates of cardiac catheterizations in Hispanic patients, increased rates of coronary artery stenting and/or CABG, particularly in Hispanic patients; and decreased length of stay in patients older than 60 years. These data support a targeted interdisciplinary CP initiative as a strategy to systematically enhance access to cardiovascular diagnosis in underserved patient populations.

The incremental value of troponin-I testing in patients with intermediate risk unstable angina

BACKGROUND

Classification of patients with unstable angina (UA) by Agency for Health Care Policy and Research (AHCPR) guidelines in the emergency department reliably stratifies risk of death or myocardial infarction (MI) for triage to outpatient evaluation (low-risk), hospitalization (high-risk), or additional testing (intermediate-risk). Cardiac troponin-I elevation may identify patients at higher risk, but the incremental value may vary with AHCPR clinical risk.

HYPOTHESIS

The objective of this study was to determine whether cardiac troponin-I had any additional value beyond triage based upon history, physical examination, and electrocardiogram, in the evaluation of patients with UA.

METHODS

In all, 212 consecutive patients with UA and normal serum creatine kinase (CK)-MB levels and elevated troponin-I were risk stratified by AHCPR guidelines to evaluate the incremental value of adding routine troponin-I measurements to our current model for risk stratification.

RESULTS

Primary events (death/nonfatal MI) occurred in 35% of high-risk, 15% of intermediate-risk, and 0% of low-risk patients (p < 0.001 by chi-square for trend). High troponin-I (> or =2.0 ng/dl) occurred in 48% of high-risk, 21% of intermediate-risk, and 19% of low-risk patients. The remaining patients in each risk group had indeterminate troponin-I levels (> or =0.4 < 2 ng/dl). Of those with high troponin-I, a primary event occurred in 36, 42, and 0% in the respective high-, intermediate-, and low-risk groups (p < 0.001). High troponin-I levels corresponded with a statistically significant increased rate of primary events only in patients at AHCPR intermediate risk: 42.4 vs. 7.3%, p < 0.001.

CONCLUSION

The AHCPR guidelines risk stratify patients with UA. High troponin-I adds significant (p < 0.001) prognostic value in the patients at AHCPR intermediate risk and should be evaluated further in larger trials of such patients.

Incremental value of upper endoscopy for triage of patients with acute non-variceal upper-GI hemorrhage

BACKGROUND

Risk scores for triage of patients with acute upper-GI hemorrhage that incorporate endoscopic variables (e.g., the complete Rockall Score) may have better test characteristics for identification of "low-risk" bleeding episodes than those (e.g., Blatchford Score, clinical Rockall Score) that rely solely on clinical variables. An endoscopy-based risk score was compared with two clinically based risk scores in a large cohort of patients hospitalized for treatment of acute upper-GI hemorrhage to quantify the incremental value of endoscopy in the identification of low-risk bleeding.

METHODS

ICD-9-CMcodes for discharge diagnosis were used to identify a cohort of patients (n=175) hospitalized at a university medical center with acute non-variceal upper-GI hemorrhage. Medical record data were abstracted by two data abstractors blinded to the study intent by using a standardized data collection instrument. Blatchford and Rockall Scores were generated for each case. Low risk was defined as a Blatchford Score of 0, a clinical Rockall Score of 0, or complete Rockall Score of 2 or less.

RESULTS

The Blatchford Score risk stratified only 14 of 175 (8%) patients with acute, non-variceal upper-GI hemorrhage as "low risk," while the clinical Rockall Score identified 12%. However, the complete Rockall Score identified the greatest number of low-risk cases, 53/175 (30%) (p < 0.0001), when compared with either the Blatchford or clinical Rockall Score.

CONCLUSIONS

The complete Rockall Score identified significantly more low-risk patients with acute upper-GI hemorrhage than either the clinical Rockall Score or the Blatchford Score. Identification of additional low-risk patients via this endoscopy-based score could lead to decreases in the use of hospital-based services, iatrogenic complications, and time lost from work or usual activity, while improving quality of care. Use of the clinical and complete Rockall Scores sequentially, with consideration of outpatient care for patients at identified as low risk, is recommended.

Safety and efficiency of emergency department assessment of chest discomfort

BACKGROUND

Most Canadian emergency departments use an unstructured, individualized approach to patients with chest pain, without data to support the safety and efficiency of this practice. We sought to determine the proportions of patients with chest discomfort in emergency departments who either had acute coronary syndrome (ACS) and were inappropriately discharged from the emergency department or did not have ACS and were held for investigation.

METHODS

Consecutive consenting patients aged 25 years or older presenting with chest discomfort to 2 urban tertiary care emergency departments between June 2000 and April 2001 were prospectively enrolled unless they had a terminal illness, an obvious traumatic cause, a radiographically identifiable cause, severe communication problems or no fixed address in British Columbia or they would not be available for follow-up by telephone. At 30 days we assigned predefined explicit outcome diagnoses: definite ACS (acute myocardial infarction [AMI] or definite unstable angina) or no ACS.

RESULTS

Of 1819 patients, 241 (13.2%) were assigned a 30-day diagnosis of AMI and 157 (8.6%), definite unstable angina. Of these 398 patients, 21 (5.3%) were discharged from the emergency department without a diagnosis of ACS and without plans for further investigation. The clinical sensitivity for detecting ACS was 94.7% (95% confidence interval [CI] 92.5%- 96.9%) and the specificity 73.8% (95% CI 71.5%- 76.0%). Of the patients without ACS or an adverse event, 71.1% were admitted to hospital or held in the emergency department for more than 3 hours.

INTERPRETATION

The current individualized approach to evaluation and disposition of patients with chest discomfort in 2 Canadian tertiary care emergency departments misses 5.3% of cases of ACS while consuming considerable health care resources for patients without coronary disease. Opportunities exist to improve both safety and efficiency.

Accuracy of a neural diagnostic tree for the identification of acute coronary syndrome in patients with chest pain and no ST-segment elevation

Identifying acute coronary syndrome is a difficult task in the emergency department because symptoms may be atypical and the electrocardiogram has low sensitivity. In this prospective cohort study done in a tertiary community emergency hospital, we developed and tested a neural diagnostic tree in 566 consecutive patients with chest pain and no ST-segment elevation for the diagnosis of acute coronary syndrome. Multivariate regression and recursive partitioning analysis allowed the construction of decision rules and of a neural tree for the diagnosis of acute myocardial infarction and acute coronary syndrome. Predictive variables of acute coronary syndrome were: age > or =60 years (odds ratio [OR] = 2.3; P = 0.0016), previous history of coronary artery disease (OR = 2.9; P = 0.0008), diabetes (OR = 2.8; P = 0.0240), definite/probable angina-type chest pain (OR = 17.3; P = 0.0000) and ischemic electrocardiogram (ECG) changes on admission (OR = 3.5; P = 0.0002). The receiver operating characteristic curve of possible diagnostic decision rules of the regression model disclosed a C-index of 0.904 (95% confidence interval = 0.878 to 0.930) for acute coronary syndrome and 0.803 (95% confidence interval 0.757 to 0.849) for acute myocardial infarction. For both disorders, sensitivities of the neural tree were 99% and 93%, respectively, and negative predictive values were both 98%. Negative likelihood ratios were 0.02 and 0.1, respectively. It is concluded that this simple and easy-to-use neural diagnostic tree was very accurate in the identification of non-ST segment elevation chest pain patients without acute coronary syndrome. Patients identified as low probability of disease could receive immediate stress testing and be discharged if the test is negative.

Acute chest pain — identification of patients at low risk for coronary events. The impact of symptoms, medical history and risk factors

BACKGROUND

The evaluation of patients with acute chest pain remains challenging, as it implies the risk of fatal misdiagnosis. It is well recognized that typical angina does not specifically identify patients at high risk. We investigated the predictive value of characteristics atypical for myocardial ischemia for exclusion of acute or subacute coronary events, focusing on patients' symptoms, medical history and risk factors.

METHODS

We prospectively studied 1288 consecutive patients presenting with acute chest pain at a non-trauma emergency department. Patients' symptoms, history and risk factors were evaluated using seven predefined criteria and assigned as typical or atypical for ischemic coronary chest pain. Positive predictive value (PPV) and 95% confidence intervals (95% CI) were calculated to predict or exclude acute myocardial infarction (AMI) and major adverse cardiac events (MACE: cardiovascular death, percutaneous coronary interventions, bypass surgery, or myocardial infarction) within six months.

RESULTS

AMI occurred in 168 patients (13%), and 6-months MACE (including AMI) overall in 240 patients (19%). Presence of four or more criteria typical for myocardial ischemia was associated with a PPV of 0.21 (0.17 to 0.25) for predicting AMI and 0.30 (0.25 to 0.35) for 6-months MACE. Presence of four or more criteria atypical for coronary ischemia was associated with a PPV of 0.94 (0.91 to 0.96) for excluding AMI and 0.93 (0.90 to 0.96) for excluding 6-months MACE. In 165 of 476 patients under 40 years of age (35%), four or more atypical criteria excluded AMI and 6-months MACE with PPVs of 0.98 (0.96 to 1.0).

CONCLUSION

Evaluation of criteria atypical for myocardial ischemia with acute chest pain may help to identify candidates for early discharge, whereas typical characteristics have very little diagnostic value.

Short-stay units and observation medicine: a systematic review

OBJECTIVES

To conduct a systematic review of how short-stay observation units (SOUs) affect the efficiency of healthcare delivery and the quality of services provided.

DATA SOURCES

MEDLINE, CINAHL, Best Evidence and The Cochrane Library were searched for the period 1 January 1960 to 31 July 2000.

STUDY SELECTION

Studies were eligible if published in English and rated at National Health and Medical Research Council evidence levels I, II-1, II-2, or II-3; 12 comparative studies published between 1985 and 1998 met these criteria.

DATA EXTRACTION

Data pertaining to clinical outcomes, length of stay, re-presentation rates, emergency department efficiency and costs of care were extracted and evaluated independently.

DATA SYNTHESIS

As there was considerable heterogeneity in the patient populations and outcomes, results were summarised rather than subjected to meta-analysis.

CONCLUSION

SOUs have the potential to increase patient satisfaction, reduce length of stay, improve the efficiency of emergency departments and improve cost effectiveness. However, SOUs have commonly been implemented alongside new clinical protocols, and it is not possible to distinguish the relative benefits of each. As demand increases, providing effective and cost-efficient care will become increasingly important. SOUs may help organisations that are attempting to streamline patient care while maintaining their quality of service delivery.

Impact of a chest-pain guideline on clinical decision-making

OBJECTIVE

To evaluate the impact of a chest-pain guideline on clinical decision-making and medium-term outcomes of patients presenting to a hospital emergency department (ED) with non-traumatic chest pain.

DESIGN

Before-and-after guideline implementation study.

SETTING

Bankstown-Lidcombe Hospital, Sydney, NSW (454-bed metropolitan teaching hospital), in the six-month periods before and after guideline implementation in February 2001.

PARTICIPANTS

Patients presenting to the ED with non-traumatic chest pain who had chest-pain assessment forms completed by ED doctors, comprising 422/768 (54.9%) of those presenting before and 461/691 (66.7%) after guideline implementation.

MAIN OUTCOME MEASURES

Appropriateness of admission/discharge decisions compared with decision of senior cardiologist based on guideline; death, recurrent chest pain, ED re-presentation and hospital readmission in the ensuing three months.

RESULTS

After guideline implementation, appropriate admission/discharge decisions increased significantly from 180/265 (68%) to 261/324 (81%) (difference, 13%; 95% CI, 6%-20%). The largest increase was for patients at moderate risk of death or acute myocardial infarction within six months, from 39/96 (38%) to 57/103 (55%) (difference, 18%; 95% CI, 4%-31%). Increases were seen for both junior doctors (interns and resident medical officers) (18%; 95% CI, 7%-30%) and senior doctors (11%; 95% CI, 2%-19%). Logistic regression showed that implementation of the guideline, seniority of assessing doctor and patient history of coronary disease were independent predictors of appropriate decisions. There was a significant decline in re-presentations to ED with recurrent chest pain in patients previously presenting with cardiac or possibly cardiac pain, from 46/201 (23%) before implementation to 32/247 (13%) after (difference, 210%; 95% CI, 217% to 23%).

CONCLUSIONS

The chest-pain guideline resulted in a significant improvement in clinical decision-making in the ED and reduced re-presentations with cardiac/possibly cardiac chest pain.

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.

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 management of patients with acute coronary syndromes: an assessment by the National Heart Attack Alert Program

BACKGROUND

The use of critical pathways for a variety of clinical conditions has grown rapidly in recent years, particularly pathways for patients with acute coronary syndromes (ACS). However, no systematic review exists regarding the value of critical pathways in this setting.

METHODS

The National Heart Attack Alert Program established a Working Group to review the utility of critical pathways on quality of care and outcomes for patients with ACS. A literature search of MEDLINE, cardiology textbooks, and cited references in any article identified was conducted regarding the use of critical pathways for patients with ACS.

RESULTS

Several areas for improving the care of patients with ACS through the application of critical pathways were identified: increasing the use of guideline-recommended medications, targeting use of cardiac procedures and other cardiac testing, and reducing the length of stay in hospitals and intensive care units. Initial studies have shown promising results in improving quality of care and reducing costs. No large studies designed to demonstrate an improvement in mortality or morbidity were identified in this literature review.

CONCLUSIONS

Critical pathways offer the potential to improve the care of patients with ACS while reducing the cost of care. Their use should improve the process and cost-effectiveness of care, but further research in this field is needed to determine whether these changes in the process of care will translate into improved clinical outcomes.

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 in the emergency department: the broad spectrum of causes

We performed a prospective study to describe the broad spectrum of causes of chest pain in patients presenting to the emergency department and to compare the diagnoses in referred patients, self-referred patients and patients rushed in by ambulance. The final diagnosis in a consecutive case series of 578 chest pain patients was established after discharge from the hospital. The underlying disorders were grouped into cardiac, respiratory, gastro-oesophageal disorders, musculoskeletal pathology, somatization disorders, other diseases and unknown. For comparison of the frequencies of the disease categories the Chi-squared test was used. Out of 578 patients, 161 (27.9%) were self-referred, 369 (63.8%) were referred by the general practitioner and 48 (8.3%) were rushed in by ambulance. Cardiac diseases represented 51.7% of the cases, myocardial infarction and unstable angina 19% and 12.8% respectively Cardiac diseases were statistically significantly less common in self-referred patients (p<0.0005). Pulmonary diseases encompassed 14.2% of the population, followed by somatization disorders (9.2%), musculoskeletal pathology (7.1%) and other causes (4.3%). In 11.1% of the cases no definite final diagnosis could be established. Somatization disorders were significantly more frequent in self-referred and ambulance patients. Cardiac and pulmonary problems are the most frequent underlying disorders in acute chest pain patients in the emergency department. Somatization disorders and musculoskeletal pathology represented respectively 19.1% and 14.8% of the non-cardiac causes. The referral pattern influenced significantly the distribution of the disease categories with more cardiac and less psychiatric disorders in referred patients.

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.

Acute ischemic syndromes. Chest pain center concept

CPCs have been developed to meet the clinical challenge posed by the diverse group of patients presenting to the ED with findings suggestive of a coronary event. Using a protocol-driven approach, high- and low-risk patients can be identified on presentation, facilitating urgent therapy in the former and triage of the latter to more deliberate management. Most CPCs focus on low-risk patients who are being increasingly managed by accelerated diagnostic protocols. These methods comprise systematic strategies that include innovative diagnostic approaches during a 6 to 12 hour period of observation with serial ECGs, continuous monitoring and cardiac biomarker measurements. A negative evaluation is usually followed by predischarge stress testing, and positive findings mandate admission. An essential aspect of the CPC strategy is continuity of care for patients with negative cardiac evaluations. Current data indicate that management of low-risk patients with chest pain in a CPC is safe accurate, and appears to be cost-effective.

Impact of troponin T determinations on hospital resource utilization and costs in the evaluation of patients with suspected myocardial ischemia

The evaluation and triage of patients with suspected myocardial ischemia in the emergency department remains challenging and costly. Previous studies of cardiac troponins have focused predominantly on patients with chest pain and have not randomized patients to different diagnostic strategies. Eight hundred fifty-six patients with suspected myocardial ischemia were prospectively randomized to receive a standard evaluation, including serial electrocardiographic and creatine phosphokinase-MB determinations (controls) or a standard evaluation with the addition of serial troponin T determinations (troponin group). The primary end points were length of stay and hospital charges. Significant reductions in length of hospital stay were seen in troponin T patients both with (3.6 vs 4.7 days; p = 0.01) and without (1.2 vs 1.6 days; p = 0.03) acute coronary syndromes compared with controls. Total hospital charges were reduced in a similar fashion in troponin patients with and without acute coronary syndromes ($15,004 vs $19,202; p = 0.01, and $4,487 vs $6,187; p = 0.17, respectively) compared with controls. Troponin patients without acute coronary syndromes had fewer hospital admissions (25% vs 31%; p = 0.04), whereas troponin patients with acute coronary syndromes had shorter telemetry and coronary care unit lengths of stay (3.5 vs 4.5 days; p = 0.03) compared with controls. Thus, utilization of troponin T in a broad spectrum of emergency department patients with suspected myocardial ischemia improves hospital resource utilization and reduces costs.

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.

[Chest pain units: state of the art of the management of patients with chest pain in the emergency department]

Chest pain is one of the most common reasons for patients coming to emergency departments. Most of these individuals end up being hospitalized due to uncertainty of the cause of their complaint. This aggressive and defensive attitude is taken by emergency physicians because some 10 to 30% of these patients actually have acute coronary syndrome. As the admission electrocardiogram and serum CK-MB level have a sensitivity of about 50% for the diagnosis of acute myocardial infarction, serial evaluation is mandatory for non-low risk patients. Inspite of this knowledge, an average of 2-3% of patients with acute myocardial infarction are erroneously released from emergency departments, what is responsible for expensive malpractice suits in the United States. Chest Pain Units were introduced in emergency practice two decades ago to improve medical care quality, reduce inappropriate hospital discharges, reduce unnecessary hospital admissions and reduce medical costs, thus making patient's assessment cost-effective. This is achieved mostly with the use of systematic diagnostic protocols by qualified and trained personnel in the emergency department setting and not in the coronary care unit.

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.