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Introduction: Chest pain is a common reason for ambulance transport. Acute coronary syndrome (ACS) and pulmonary embolism (PE) risk assessments, such as history, electrocardiogram, age, risk factors (HEAR); Emergency Department Assessment of Chest Pain Score (EDACS); Pulmonary Embolism Rule-out Criteria (PERC); and revised Geneva score, are well validated for emergency department (ED) use but have not been translated to the prehospital setting. The objectives of this study were to evaluate the 1) prehospital completion rate and 2) inter-rater reliability of chest pain risk assessments. Methods: We conducted a prospective observational cohort study in two emergency medical services (EMS) agencies (April 18, 2018 – January 2, 2019). Adults with acute, non-traumatic chest pain without ST-elevation myocardial infarction or unstable vital signs were accrued. Paramedics were trained to use the HEAR, EDACS, PERC, and revised Geneva score assessments. A subset of patients (a priori goal of N = 250) also had the four risk assessments completed by their treating clinicians in the ED, who were blinded to the EMS risk assessments. Outcomes were 1) risk assessments completion rate and 2) inter-rater reliability between EMS and ED assessments. An a priori goal for completion rate was set as >75%. We computed kappa with corresponding 95% confidence intervals (CI) for each risk assessment as a measure of inter-rater reliability. Acceptable agreement was defined a priori as kappa ≥ 0.60. Results: During the study period, 837 patients with acute chest pain were accrued. The median age was 54 years, interquartile range 43-66, with 53% female and 51% Black. Completion rates for each risk assessment were above goal: the HEAR score was completed on 95.1% (796/837), EDACS on 92.0% (770/837), PERC on 89.4% (748/837), and revised Geneva score on 90.7% (759/837) of patients. We assessed agreement in a subgroup of 260 patients. The HEAR score had a kappa of 0.51 (95% CI, 0.41- 0.61); EDACS was 0.60 (95% CI, 0.49-0.72); PERC was 0.71 (95% CI, 0.61-0.81); and revised Geneva score was 0.51 (95% CI, 0.39-0.62). Conclusion: The completion rate of risk assessments for ACS and PE was high for prehospital field personnel. The PERC and EDACS both demonstrated acceptable agreement between paramedics and clinicians in the ED, although assessments with better agreement are likely needed.

Background Expediting the measurement of serum troponin by leveraging EMS blood collection could reduce the diagnostic time for patients with acute chest pain and help address Emergency Department (ED) overcrowding. However, this practice has not been examined among an ED chest pain patient population in the United States. Methods A prospective observational cohort study of adults with non-traumatic chest pain without ST-segment elevation myocardial infarction was conducted in three EMS agencies between 12/2016–4/2018. During transport, paramedics obtained a patient blood sample that was sent directly to the hospital core lab for troponin measurement. On ED arrival HEART Pathway assessments were completed by ED providers as part of standard care. ED providers were blinded to troponin results from EMS blood samples. To evaluate the potential impact on length of stay (LOS), the time difference between EMS blood draw and first clinical ED draw was calculated. To determine the safety of using troponin measures from EMS blood samples, the diagnostic performance of the HEART Pathway for 30-day major adverse cardiac events (MACE: composite of cardiac death, myocardial infarction (MI), coronary revascularization) was determined using EMS troponin plus arrival ED troponin and EMS troponin plus a serial 3-h ED troponin. Results The use of EMS blood samples for troponin measures among 401 patients presenting with acute chest pain resulted in a mean potential reduction in LOS of 72.5 ± SD 35.7 min. MACE at 30 days occurred in 21.0% (84/401), with 1 cardiac death, 78 MIs, and 5 revascularizations without MI. Use of the HEART Pathway with EMS and ED arrival troponin measures yielded a NPV of 98.0% (95% CI: 89.6–100). NPV improved to 100% (95% CI: 92.9–100) when using the EMS and 3-h ED troponin measures. Conclusions EMS blood collection used for core lab ED troponin measures could significantly reduce ED LOS and appears safe when integrated into the HEART Pathway.

BACKGROUND: The HEART Pathway is an accelerated diagnostic protocol for Emergency Department patients with possible acute coronary syndrome. The objective was to compare the safety and effectiveness of the HEART Pathway among women vs men and whites vs non-whites. METHODS: A subgroup analysis of the HEART Pathway Implementation Study was conducted. Adults with chest pain were accrued from November 2013 to January 2016 from 3 Emergency Departments in North Carolina. The primary outcomes were death and myocardial infarction (MI) and hospitalization rates at 30 days. Logistic regression evaluated for interactions of accelerated diagnostic protocol implementation with sex or race and changes in outcomes within subgroups. RESULTS: A total of 8,474 patients were accrued, of which 53.6% were female and 34.0% were non-white. The HEART Pathway identified 32.6% of females as low-risk vs 28.5% of males (P = 002) and 35.6% of non-whites as low-risk vs 28.0% of whites (P < .0001). Among low-risk patients, death or MI at 30 days occurred in 0.4% of females vs 0.5% of males (P = .70) and 0.5% of non-whites vs 0.3% of whites (P = .69). Hospitalization at 30 days was reduced by 6.6% in females (aOR: 0.74, 95% CI: 0.64–0.85), 5.1% in males (aOR: 0.87, 95% CI: 0.75–1.02), 8.6% in non-whites (aOR: 0.72, 95% CI: 0.60–0.86), and 4.5% in whites (aOR: 0.83, 95% CI: 0.73–0.94). Interactions were not significant. CONCLUSION: Women and non-whites are more likely to be classified as low-risk by the HEART Pathway. HEART Pathway implementation is associated with decreased hospitalizations and a very low death and MI rate among low-risk patients regardless of sex or race.

BackgroundThe HEART Pathway combines a History ECG Age Risk factor (HEAR) score and serial troponins to risk stratify patients with acute chest pain. However, it is unclear whether patients with HEAR scores of <1 require troponin testing. The objective of this study is to measure the major adverse cardiac event (MACE) rate among patients with <1 HEAR scores and determine whether serial troponin testing is needed to achieve a miss rate MethodsA secondary analysis of the HEART Pathway Implementation Study was conducted. HEART Pathway risk assessments (HEAR scores and serial troponin testing at 0 and 3 hours) were completed by the providers on adult patients with chest pain from three US sites between November 2014 and January 2016. MACE (composite of death, myocardial infarction (MI) and coronary revascularisation) at 30 days was determined. The proportion of patients with HEAR scores of <1 diagnosed with MACE within 30 days was calculated. The impact of troponin testing on patients with HEAR scores of <1 was determined using Net Reclassification Improvement Index (NRI).ResultsProviders completed HEAR assessments on 4979 patients and HEAR scores<1 was 97.8% (95%CI 94.5% to 99.4%) and 99.1% (95% CI 97.7% to 99.8%), respectively, and were not improved by troponin testing. Troponin testing in patients with HEAR <1 correctly reclassified two patients diagnosed with MACE, and was elevated among seven patients without MACE yielding an NRI of 0.9% (95%CI −0.7 to 2.4%).ConclusionThese data suggest that patients with HEAR scores of 0 and 1 represent a very low-risk group that may not require troponin testing to achieve a missed MACE rate Trial registration numberNCT02056964

BackgroundThe History Electrocardiogram Age Risk factor Troponin (HEART) Pathway and Emergency Department Assessment of Chest pain Score (EDACS) are validated accelerated diagnostic pathways designed to risk stratify patients presenting to the emergency department with chest pain. Data from large multisite prospective studies comparing these accelerated diagnostic pathways are limited.MethodsThe HEART Pathway Implementation is a prospective three-site cohort study, which accrued adults with symptoms concerning for acute coronary syndrome. Physicians completed electronic health record HEART Pathway and EDACS risk assessments on participants. Major adverse cardiac events (death, myocardial infarction and coronary revascularisation) at 30 days were determined using electronic health record, insurance claims and death index data. Test characteristics for detection of major adverse cardiac events were calculated for both accelerated diagnostic pathways and McNemar’s tests were used for comparisons.Results5799 patients presenting to the emergency department were accrued, of which HEART Pathway and EDACS assessments were completed on 4399. Major adverse cardiac events at 30 days occurred in 449/4399 (10.2%). The HEART Pathway identified 38.4% (95% CI 37.0% to 39.9%) of patients as low-risk compared with 58.1% (95% CI 56.6% to 59.6%) identified as low-risk by EDACS (pConclusionsEDACS identifies a larger proportion of patients as low-risk than the HEART Pathway, but has a higher missed major adverse cardiac events rate at 30 days. Physicians will need to consider their risk tolerance when deciding whether to adopt the HEART Pathway or EDACS accelerated diagnostic pathway.Trial registration numberNCT02056964.

Objective: Use of point-of-care (POC) troponin (cTn) testing in the Emergency Department (ED) is well established. However, data examining POC cTn measurement in the prehospital setting, during amb...

BackgroundPrior studies suggest monocyte chemoattractant protein-1 (MCP-1) may be useful for risk stratifying ED patients with chest pain. We hypothesise that MCP-1 will be predictive of 90-day major adverse cardiovascular events (MACEs) in non-low-risk patients.MethodsA case–control study was nested within a prospective multicentre cohort (STOP-CP), which enrolled adult patients being evaluated for acute coronary syndrome at eight US EDs from 25 January 2017 to 06 September 2018. Patients with a History, ECG, Age, and Risk factor score (HEAR score) ≥4 or coronary artery disease (CAD), a non-ischaemic ECG, and non-elevated contemporary troponins at 0 and 3 hours were included. Cases were patients with 90-day MACE (all-cause death, myocardial infarction or revascularisation). Controls were patients without MACE selected with frequency matching using age, sex, race, and HEAR score or the presence of CAD. Serum MCP-1 was measured. Sensitivity and specificity were determined for cut-off points of 194 pg/mL, 200 pg/mL, 238 pg/mL and 281 pg/mL. Logistic regression adjusting for age, sex, race, and HEAR score/presence of CAD was used to determine the association between MCP-1 and 90-day MACE. A separate logistic model also included high-sensitivity troponin (hs-cTnT).ResultsAmong 40 cases and 179 controls, there was no difference in age (p=0.90), sex (p=1.00), race (p=0.85), or HEAR score/presence of CAD (p=0.89). MCP-1 was similar in cases (median 191.9 pg/mL, IQR: 161.8–260.1) and controls (median 196.6 pg/mL, IQR: 163.0–261.1) (p=0.48). At a cut-off point of 194 pg/mL, MCP-1 was 50.0% (95% CI 33.8% to 66.2%) sensitive and 46.9% (95% CI 39.4% to 54.5%) specific for 90-day MACE. After adjusting for covariates, MCP-1 was not associated with 90-day MACE at any cut-off point (at 194 pg/mL, OR 0.88 (95% CI 0.43 to 1.79)). When including hs-cTnT in the model, MCP-1 was not associated with 90-day MACE at any cut-off point (at 194 pg/mL, OR 0.85 (95% CI 0.42 to 1.73)).ConclusionMCP-1 is not predictive of 90-day MACE in patients with non-low-risk chest pain.

BACKGROUND: Data evaluating the impact of the history, ECG, age, risk factors, and troponin (HEART) Pathway on observation unit (OU) use is limited. The objective of this study is to determine how HEART Pathway implementation affects OU use. METHODS: An analysis of OU registry data from October 2012 to October 2016, 2 years before and after HEART Pathway implementation at an academic medical center, was conducted. Adult patients placed in the OU for chest pain were included. The proportion of patients placed in the OU chest pain protocol per total OU volume and hospitalization and myocardial infarction (MI) rates were determined. Proportions before versus after implementation were compared using χ(2) tests and age was compared using a Mann-Whitney U test. RESULTS: During the study period, 1688 patients with chest pain before HEART Pathway implementation and 1692 after were included. The proportion of chest pain patients in the OU per total OU volume decreased following implementation from (57% [1688/2968] to 43.6% [1692/3882]; P < 0.001). Before HEART Pathway implementation, the hospitalization rate was 10.4% (175/1688) versus 12.4% (210/1692) after (P = 0.07). More patients were diagnosed with MI following implementation (0.8% [14/1665] vs. 2.0% [33/1686]; P = 0. 008). Median age was older postimplementation (52 years [IQR: 45–59 years] vs. 54 years [IQR: 48–64 years]; P < 0. 001). CONCLUSIONS: HEART Pathway implementation resulted in management of higher risk patients in the OU. Following implementation, OU chest pain patients were older and were more likely to be hospitalized or diagnosed with MI.

The HEART Pathway is a validated risk stratification protocol for Emergency Department patients with chest pain that has yet to be tested in the prehospital setting. This study seeks to test the performance of a prehospital modified HEART Pathway (PMHP). A prospective cohort study of adults with chest pain without ST-segment elevation myocardial infarction was conducted at three EMS agencies between 12/2016-1/2018. To complete a PMHP assessment, paramedics drew blood, measured point-of-care (POC) troponin (i-STAT; Abbott Point of Care) and calculated a HEAR score. Patients were stratified into three groups: high-risk based on an elevated troponin, low-risk based on a HEAR score

Background: The HEART Pathway (history, ECG, age, risk factors, and initial troponin) is an accelerated diagnostic protocol designed to identify low-risk emergency department patients with chest pain for early discharge without stress testing or angiography. The objective of this study was to determine whether implementation of the HEART Pathway is safe (30-day death and myocardial infarction rate Methods: A prospective pre-post study was conducted at 3 US sites among 8474 adult emergency department patients with possible acute coronary syndrome. Patients included were ≥21 years old, investigated for possible acute coronary syndrome, and had no evidence of ST-segment–elevation myocardial infarction on ECG. Accrual occurred for 12 months before and after HEART Pathway implementation from November 2013 to January 2016. The HEART Pathway accelerated diagnostic protocol was integrated into the electronic health record at each site as an interactive clinical decision support tool. After accelerated diagnostic protocol integration, ED providers prospectively used the HEART Pathway to identify patients with possible acute coronary syndrome as low risk (appropriate for early discharge without stress testing or angiography) or non-low risk (appropriate for further in-hospital evaluation). The primary safety and effectiveness outcomes, death, and myocardial infarction (MI) and hospitalization rates at 30 days were determined from health records, insurance claims, and death index data. Results: Preimplementation and postimplementation cohorts included 3713 and 4761 patients, respectively. The HEART Pathway identified 30.7% as low risk; 0.4% of these patients experienced death or MI within 30 days. Hospitalization at 30 days was reduced by 6% in the postimplementation versus preimplementation cohort (55.6% versus 61.6%; adjusted odds ratio, 0.79; 95% CI, 0.71–0.87). During the index visit, more MIs were detected in the postimplementation cohort (6.6% versus 5.7%; adjusted odds ratio, 1.36; 95% CI, 1.12–1.65). Rates of death or MI during follow-up were similar (1.1% versus 1.3%; adjusted odds ratio, 0.88; 95% CI, 0.58–1.33). Conclusions: HEART Pathway implementation was associated with decreased hospitalizations, increased identification of index visit MIs, and a very low death and MI rate among low-risk patients. These findings support use of the HEART Pathway to identify low-risk patients who can be safely discharged without stress testing or angiography. Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT02056964.

Background Patients from racial and ethnic minority groups presenting to the Emergency Department (ED) with chest pain experience lower odds of receiving stress testing compared with nonminorities. Studies have demonstrated that care pathways administered within the ED can reduce health disparities, but this has yet to be studied as a strategy to increase stress testing equity. Methods A secondary analysis from 3 randomized clinical trials involving ED patients with acute chest pain was performed to determine whether a care pathway, ACES (Accelerated Chest pain Evaluation with Stress imaging), reduces the racial disparity in index visit cardiac testing between African American (AA) and White patients. Three hundred thirty-four participants with symptoms and findings indicating intermediate to high risk for acute coronary syndrome were enrolled in 3 clinical trials. Major exclusions were ST-segment elevation, initial troponin elevation, and hemodynamic instability. Participants were randomly assigned to receive usual inpatient care, or ACES. The ACES care pathway includes placement in observation for serial cardiac markers, with an expectation for stress imaging. The primary outcome was index visit objective cardiac testing, compared among AA and White participants. Results AA participants represented 111/329 (34%) of the study population, 80/220 (36%) of the ACES group and 31/109 (28%) of the usual care group. In usual care, objective testing occurred less frequently among AA (22/31, 71%) than among White (69/78, 88%, P = 0.027) participants, primarily driven by cardiac catheterization (3% vs. 24%; P = 0.012). In ACES, testing rates did not differ by race [AA 78/80 (98%) vs. White 138/140 (99%); P = 0.623]. At 90 days, death, MI, and revascularization did not differ in either group between AA and White participants. Conclusions A care pathway with the expectation for stress imaging eliminates the racial disparity among AA and White participants with chest pain in the acquisition of index-visit cardiovascular testing.

Coronary computed tomography angiography (CCTA) has been shown to be highly sensitive for coronary artery disease and acute coronary syndrome.1,2 Few studies have evaluated changes in medical management after CCTA.3,4 Prior studies suggest increases in medical management in the cardiology setting, but none has directly compared CCTA to standard emergency department (ED) care. We sought to determine the difference in initiation of aspirin or statins depending on whether patients were evaluated with CCTA or standard care for acute chest pain. This is a prespecified analysis of a randomized controlled multicenter trial comparing a CCTA-based strategy with traditional rule-out approaches for low- to intermediate-risk patients presenting to the ED with chest pain and possible acute coronary syndrome (ClinicalTrials.gov number: NCT00933400). The full study protocol has been published elsewhere.1 Briefly, patients ≥30 years of age with possible acute coronary syndrome were enrolled and randomized in EDs or observation units at 5 sites. This study was approved by the institutional review boards at participating sites, and all patients provided written informed consent. The degree of maximal stenosis was defined as the maximal stenosis reported from the CCTA scan and was categorized as follows: none, no stenosis; mild, 1% to 49%; moderate, 50% to …

Objective The objective was to determine the impact of the HEART Pathway on health care utilization and safety outcomes at 1 year in patients with acute chest pain. Methods Adult emergency department (ED) patients with chest pain (N = 282) were randomized to the HEART Pathway or usual care. In the HEART Pathway arm, ED providers used the HEART score and troponin measures (0 and 3 hours) to risk stratify patients. Usual care was based on American College of Cardiology/American Heart Association guidelines. Major adverse cardiac events (MACE-cardiac death, myocardial infarction [MI], or coronary revascularization), objective testing (stress testing or coronary angiography), and cardiac hospitalizations and ED visits were assessed at 1 year. Randomization arm outcomes were compared using Fisher's exact tests. Results A total of 282 patients were enrolled, with 141 randomized to each arm. MACE at 1 year occurred in 10.6% (30/282): 9.9% in the HEART Pathway arm (14/141; 10 MIs, four revascularizations without MI) versus 11.3% in usual care (16/141; one cardiac death, 13 MIs, two revascularizations without MI; p = 0.85). Among low-risk HEART Pathway patients, 0% (0/66) had MACE, with a negative predictive value (NPV) of 100% (95% confidence interval = 93%-100%). Objective testing through 1 year occurred in 63.1% (89/141) of HEART Pathway patients compared to 71.6% (101/141) in usual care (p = 0.16). Nonindex cardiac-related hospitalizations and ED visits occurred in 14.9% (21/141) and 21.3% (30/141) of patients in the HEART Pathway versus 10.6% (15/141) and 16.3% (23/141) in usual care (p = 0.37, p = 0.36). Conclusions The HEART Pathway had a 100% NPV for 1-year safety outcomes (MACE) without increasing downstream hospitalizations or ED visits. Reduction in 1-year objective testing was not significant.

Background Animal studies suggest that monocyte chemoattractant protein-1 (MCP-1) is a promising biomarker for coronary artery atherosclerosis (CAA), but human studies have been inconclusive. Objective To determine potential relationships between plasma MCP-1 and CAA in patients with acute chest pain. Methods A secondary analysis of 150 patients enrolled in emergency department chest pain risk stratification clinical investigations was conducted. Participants with stored blood and known coronary phenotypes (determined by coronary angiography) were selected using stratified randomization such that 50 patients were included into 3 groups: (1) no angiographic evidence of CAA, (2) nonobstructive CAA, and (3) obstructive CAA (stenosis ≥ 70%). Plasma MCP-1 levels were determined by enzyme-linked immunosorbent assay. The association between MCP-1 and obstructive CAA or any CAA was modeled using logistic regression. Variables in the unreduced model included age, sex, race, prior diagnosis of CAA or acute coronary syndrome, hyperlipidemia, hypertension, diabetes, smoking, and cardiac troponin I measurement. Results Among the 150 participants, 65.3% (98/150) had invasive coronary angiography and 34.7% (52/150) had coronary computed tomographic angiography. Myocardial infarction occurred in 27.3% (41/150) and coronary revascularization occurred in 26% (39/150) of the participants. Each 10 pg/mL increase in MCP-1 measurement was associated with an odds ratio of 1.12 (95% confidence interval, 1.06-1.19) for obstructive CAA. MCP-1 remained a significant predictor of obstructive CAA and any CAA after adjustment for age, sex, race, traditional cardiac risk factors, and cardiac troponin I. Conclusions MCP-1 is independently associated with CAA among emergency department patients with chest pain.

An initial electrocardiogram (ECG) and serial troponin measurements are both independently and incrementally predictive of acute coronary syndrome in patients presenting with undifferentiated chest pain in the Emergency Department (ED). However, it is unclear if serial (ECGs) add significant to the contemporary diagnostic evaluation of this patient group. The ASAP CATH study was a single center, prospective study that enrolled patients presenting to an ED with undifferentiated chest pain. In addition to standard clinical evaluation, serial ECGs were performed at 90-minute intervals to evaluate whether serial changes suggestive of ischemia developed (Q waves, ST elevation or depression, or T-wave inversion). Total 365 subjects were enrolled from March 2014 to May 2015. Serial ECG changes developed in 6.6% (n = 24 of 365), the most common being the development of T-wave inversion (66.7%, n = 16 of 24). The sensitivity and positive predictive value of serial ECG changes were poor (30%), with a less areas under the curve (0.55) compared with serial troponins alone (0.83). The addition of serial ECG changes to Thrombolysis In Myocardial Infarction risk scoring showed a decrease in the net reclassification index for major adverse cardiovascular events (-0.04, p0.1) and was not significant for the prediction of major adverse cardiovascular events and/or acute coronary syndrome in 30 days (-0.003, p = 0.94). In conclusion, routine serial ECG evaluation for patients presenting with undifferentiated chest pain in the ED may not significantly improved diagnostic prognosis beyond current standard evaluation modalities.

IntroductionThe History, Electrocardiogram (ECG), Age, Risk Factors, and Troponin (HEART) score is a decision aid designed to risk stratify emergency department (ED) patients with acute chest pain. It has been validated for ED use, but it has yet to be evaluated in a prehospital setting.HypothesisA prehospital modified HEART score can predict major adverse cardiac events (MACE) among undifferentiated chest pain patients transported to the ED.MethodsA retrospective cohort study of patients with chest pain transported by two county-based Emergency Medical Service (EMS) agencies to a tertiary care center was conducted. Adults without ST-elevation myocardial infarction (STEMI) were included. Inter-facility transfers and those without a prehospital 12-lead ECG or an ED troponin measurement were excluded. Modified HEART scores were calculated by study investigators using a standardized data collection tool for each patient. All MACE (death, myocardial infarction [MI], or coronary revascularization) were determined by record review at 30 days. The sensitivity and negative predictive values (NPVs) for MACE at 30 days were calculated.ResultsOver the study period, 794 patients met inclusion criteria. A MACE at 30 days was present in 10.7% (85/794) of patients with 12 deaths (1.5%), 66 MIs (8.3%), and 12 coronary revascularizations without MI (1.5%). The modified HEART score identified 33.2% (264/794) of patients as low risk. Among low-risk patients, 1.9% (5/264) had MACE (two MIs and three revascularizations without MI). The sensitivity and NPV for 30-day MACE was 94.1% (95% CI, 86.8-98.1) and 98.1% (95% CI, 95.6-99.4), respectively.ConclusionsPrehospital modified HEART scores have a high NPV for MACE at 30 days. A study in which prehospital providers prospectively apply this decision aid is warranted.StopyraJP, HarperWS, HigginsTJ, ProkesovaJV, WinslowJE, NelsonRD, AlsonRL, DavisCA, RussellGB, MillerCD, MahlerSA. Prehospital modified HEART score predictive of 30-day adverse cardiac events. Prehosp Disaster Med. 2018;33(1):58–62.

Approximately 8 to 10 million patients complaining of chest pain present to emergency departments (EDs) annually in the United States.1 In an attempt to avoid missing the diagnosis of acute coronary syndrome (ACS), emergency physicians use liberal testing strategies in patients with acute chest pain. This results in more than 50% of ED patients with acute chest pain receiving comprehensive cardiac evaluations (serial cardiac biomarkers and stress testing or angiography) at an estimated cost of $10 to $13 billion annually,2–6 yet fewer than 10% of these patients are ultimately diagnosed with ACS.6–10 Current care patterns for patients with acute chest pain fail to focus health system resources on patients likely to benefit. Among low-risk patients who have ACS rates as low as 2%, stress testing and cardiac imaging is associated with a substantial number of false-positive and nondiagnostic tests, which leads to additional unnecessary and often invasive procedures.11 Consensus among health system leaders, clinicians, and educators is building regarding the need to more efficiently evaluate patients with acute chest pain.12 The 2-hour accelerated diagnostic protocol (ADAPT),13,14 which combines 0- and 2-hour cardiac troponin (cTn) tests, electrocardiograms (ECGs), and an adapted Thombolysis in Myocardial Infarction (TIMI) score, is a recently developed decision rule designed to identify ED patients safe for early discharge. Previous studies in the Asia-Pacific region have demonstrated that ADAPT can classify 20% of patients with acute chest pain for early discharge while simultaneously achieving high sensitivity (97.9% to 99.7%) for major adverse cardiac events (MACE) at 30 days.13,15 Based on these studies, many believe that ADAPT has the potential to more efficiently focus inpatient resources and objective cardiac testing (stress testing or angiography) on patients likely to benefit. However, the performance of ADAPT within a cohort of US ED patients has yet to be examined. We designed a secondary data analysis of the American College of Radiology Imaging Network (ACRIN) PA 4005 cohort to determine the validity of ADAPT in a group of U.S. ED patients with suspected ACS. Specifically we sought to determine if ADAPT can classify 20% or more patients with acute chest pain as safe for early discharge while maintaining high sensitivity and negative predictive value (NPV) for MACE. While the precise value of an acceptable sensitivity and NPV for MACE is a matter of considerable debate, many believe that a successful chest pain risk stratification strategy must achieve >99% NPV (corresponding with a < 1% missed MACE rate among patients with a low-risk assessment) and approach a 99% sensitivity.16

Background— Coronary artery calcification (CAC) may impair diagnostic assessment of coronary computed tomography angiography (CTA). We determined whether CAC affects efficiency of coronary CTA in patients with suspected acute coronary syndrome (ACS). Methods and Results— This is a pooled analysis of ACRIN-PA (American College of Radiology Imaging Network–Pennsylvania) 4005 and the ROMICAT-II trial (Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography) comparing an initial coronary CTA strategy to standard of care in acute chest pain patients. In the CTA arms, we investigated appropriateness of downstream testing, cost, and diagnostic yield to identify patients with obstructive coronary artery disease on subsequent invasive coronary angiography across CAC score strata (Agatston score: 0, >0–10, >10–100, >100–400, >400). Out of 1234 patients (mean age 51±8.8 years), 80 (6.5%) had obstructive coronary artery disease (≥70% stenosis) and 68 (5.5%) had ACS. Prevalence of obstructive coronary artery disease (1%–64%), ACS (1%–44%), downstream testing (4%–72%), and total (2337–8484 US$) and diagnostic cost (2310–6678 US$) increased across CAC strata ( P 400, cost to diagnose one ACS was lowest in this group (19 283 US$ versus 464 399 US$) as compared with patients without CAC. The diagnostic yield of invasive coronary angiography was highest in patients with CAC>400 (87% versus 38%). Conclusions— Downstream testing, total, and diagnostic cost increased with increasing CAC, but were found to be appropriate because obstructive coronary artery disease and ACS were more prevalent in patients with high CAC. In patients with acute chest pain undergoing coronary CTA, cost-efficient testing and excellent diagnostic yield can be achieved even with high CAC burden. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifiers: NCT01084239 and NCT00933400.

Background Regular exercise is thought to be protective against coronary artery disease. As a result, some physicians believe that the likelihood of acute coronary syndrome (ACS) in patients with acute chest pain is reduced in those who exercise regularly. We studied the association between self-reported frequency of exercising and the likelihood of ACS in patients presenting to the Emergency Department (ED) with chest pain. Methods A multi-center prospective, descriptive, cohort study design was used in ED patients to determine whether the risk of ACS was reduced in patients who self-reported regular exercise. Results There were 1093 patients enrolled. Median (interquartile range) age was 57 (48–67) years; 506 (45.7%) were female. ACS was diagnosed in 248 (22.7%) patients. Patients who did not exercise at least monthly were more likely to be diagnosed with ACS than those who did (129/466 [27.7%] vs. 119/627 [19.0%]; odds ratio 1.63, 95% CI 1.23–2.17). After adjusting for age, gender, body mass index, smoking, and prior history, limited exercise was still associated with ACS (adjusted odds ratio 1.52, 95% CI 1.10–2.10). There was no apparent association between frequency and intensity of exercise and risk of ACS. Conclusion Although self-reported frequency of exercise was significantly associated with a decrease in ACS in ED patients with chest pain, it should not be used to exclude ACS in symptomatic ED patients.

On virtually every shift, Emergency Department providers care for patients with chest pain. With each encounter, the provider has the difficult task of determining if the patient’s pain is of cardiac or non-cardiac origin. This is a high-stakes decision, as patients discharged with an incorrect diagnosis of non-cardiac chest pain are at high risk for morbidity and mortality, while the provider is at high risk for a medical malpractice claim (Pope et al., N Engl J Med 342(16):1163–1170, 2000; Amsterdam et al., Circulation 122(17):1756–1776, 2010). Diagnostic imaging studies, such as coronary computed tomography angiography, cardiac magnetic resonance imaging, stress echocardiography, and nuclear imaging, play an important role in the risk stratification of patients presenting with chest pain or other symptoms concerning for acute coronary syndrome (ACS). This article will evaluate and summarize the recent evidence relevant to diagnostic imaging modalities used to exclude ACS.

Background The no objective testing rule (NOTR) is a decision aid designed to safely identify emergency department (ED) patients with chest pain who do not require objective testing for coronary artery disease. Objectives The objective was to validate the NOTR in a cohort of U.S. ED patients with acute chest pain and compare its performance to the HEART Pathway. Methods A secondary analysis of 282 participants enrolled in the HEART Pathway randomized controlled trial was conducted. Each patient was classified as low risk or at risk by the NOTR. Sensitivity for major adverse cardiac events (MACE) at 30 days was calculated in the entire study population. NOTR and HEART Pathways were compared among patients randomized to the HEART Pathway in the parent trial using McNemar's test and the net reclassification improvement (NRI). Results Major adverse cardiac events occurred in 22/282 (7.8%) participants, including no deaths, 16/282 (5.6%) with myocardial infarction (MI), and 6/282 (2.1%) with coronary revascularization without MI. NOTR was 100% (95% confidence interval [CI] = 84.6%–100%) sensitive for MACE and identified 78/282 patients (27.7%, 95% = CI 22.5–33.3%) as low risk. In the HEART Pathway arm (n = 141), both NOTR and HEART Pathway identified all patients with MACE as at risk. Compared to NOTR, the HEART Pathway was able to correctly reclassify 27 patients without MACE as low risk, yielding a NRI of 20.8% (95% CI = 11.3%–30.2%). Conclusions Within a U.S. cohort of ED patients with chest pain, the NOTR and HEART Pathway were 100% sensitive for MACE at 30 days. However, the HEART Pathway identified more patients suitable for early discharge than the NOTR.

Introduction The HEART Pathway is a diagnostic protocol designed to identify low-risk patients presenting to the emergency department with chest pain that are safe for early discharge. This protocol has been shown to significantly decrease health care resource utilization compared with usual care. However, the impact of the HEART Pathway on the cost of care has yet to be reported. Methods and Results We performed a cost analysis of patients enrolled in the HEART Pathway trial, which randomized participants to either usual care or the HEART Pathway protocol. For low-risk patients, the HEART Pathway recommended early discharge from the emergency department without further testing. We compared index visit cost, cost at 30 days, and cardiac-related health care cost at 30 days between the 2 treatment arms. Costs for each patient included facility and professional costs. Cost at 30 days included total inpatient and outpatient costs, including the index encounter, regardless of etiology. Cardiac-related health care cost at 30 days included the index encounter and costs adjudicated to be cardiac-related within that period. Two hundred seventy of the 282 patients enrolled in the trial had cost data available for analysis. There was a significant reduction in cost for the HEART Pathway group at 30 days (median cost savings of $216 per individual), which was most evident in low-risk (Thrombolysis In Myocardial Infarction score of 0-1) patients (median savings of $253 per patient) and driven primarily by lower cardiac diagnostic costs in the HEART Pathway group. Conclusions Using the HEART Pathway as a decision aid for patients with undifferentiated chest pain resulted in significant cost savings.

Background: The 2-hour accelerated diagnostic protocol (ADAPT) and the history electrocardiogram age risk factors troponin (HEART) Pathway are decision aids designed to identify Emergency Department (ED) patients with chest pain who are safe for early discharge. Both have demonstrated high sensitivity (>99%) for major adverse cardiac events (MACE) at 30 days and early discharge rates ≥20%. The objective of this study is to compare the sensitivity and early discharge rates of the ADAPT and HEART Pathway decision aids in a cohort of ED patients with acute chest pain. Methods: A secondary analysis of participants enrolled and randomized to the HEART Pathway arm of the HEART pathway randomized controlled trial was conducted. Each patient was prospectively classified as low risk (suitable for early discharge) or high risk by ADAPT and the HEART Pathway. Sensitivity for MACE at 30 days and the number of patients identified as low-risk were calculated for each decision aid. Decision aid performance was compared using McNemar’s test. Results: MACE occurred in 8 of 141 (5.7%); there were no deaths, 7 patients had myocardial infarction, and 1 patient had coronary revascularization without myocardial infarction. ADAPT and the HEART pathway identified all patients with MACE as high risk; sensitivity for MACE of 100% [95% confidence interval (CI): 63–100%]. ADAPT identified 34 of 141 patients (24%; 95% CI: 17–32%) as low-risk, whereas the Heart pathway identified 66 of 141 patients (47%, 95% CI: 38–55%) as low risk (P Conclusions: Within a cohort of ED patients with acute chest pain, ADAPT and the HEART pathway had high sensitivity for MACE. The HEART pathway outperformed ADAPT by correctly identifying more patients as low risk and safe for early discharge.

Background Most patients presenting to US Emergency Departments (ED) with chest pain are hospitalized for comprehensive testing. These evaluations cost the US health system >$10 billion annually, but have a diagnostic yield for acute coronary syndrome (ACS) of 5000 patient encounters. The HEART Pathway has been fully integrated into health system electronic medical records, providing real-time decision support to our providers. Conclusions We hypothesize that the HEART Pathway will safely reduce healthcare utilization. This study could provide a model for delivering high-value care to the 8-10 million US ED patients with acute chest pain each year. ClinicalTrial Clinicaltrials.gov NCT02056964; https://clinicaltrials.gov/ct2/show/NCT02056964 (Archived by WebCite at http://www.webcitation.org/6ccajsgyu)

ACADEMIC EMERGENCY MEDICINE 2012; 19:673–682 © 2012 by the Society for Academic Emergency Medicine Abstract Objectives: Identifying the likelihood of a patient having coronary artery disease (CAD) at the time of emergency department (ED) presentation with chest pain could reduce the need for stress testing or coronary imaging after myocardial infarction (MI) has been excluded. The authors aimed to determine if a novel cardiac biomarker consisting of plasma cholesteryl ester (CE) levels typically derived from the activity of the enzyme acyl-CoA:cholesterol acyltransferase (ACAT2) are predictive of CAD in a clinical model. Methods: A single-center prospective cohort design enrolled participants with symptoms of acute coronary syndrome (ACS) undergoing coronary computed tomography angiography (CCTA) or invasive angiography. Plasma samples were analyzed for CE composition with mass spectrometry. The primary endpoint was any CAD determined at angiography. Multivariable logistic regression analyses were used to estimate the relationship between the sum of the plasma concentrations from cholesteryl palmitoleate (16:1) and cholesteryl oleate (18:1) (defined as ACAT2-CE) and the presence of CAD. The added value of ACAT2-CE to the model was analyzed comparing the C-statistics and integrated discrimination improvement (IDI). Results: The study cohort was composed of 113 participants with a mean (± standard deviation [SD]) age of 49 (±11.7) years, 59% had CAD at angiography, and 23% had an MI within 30 days. The median (interquartile range [IQR]) plasma concentration of ACAT2-CE was 938 μmol/L (IQR = 758 to 1,099 μmol/L) in patients with CAD and 824 μmol/L (IQR = 683 to 998 μmol/L) in patients without CAD (p = 0.03). When considered with age, sex, and the number of conventional CAD risk factors, ACAT2-CE levels were associated with a 6.5% increased odds of having CAD per 10 μmol/L increase in concentration. The addition of ACAT2-CE significantly improved the C-statistic (0.89 vs. 0.95, p = 0.0035) and IDI (0.15, p

Objective The aim of this study was to determine if patients presenting with symptoms of acute coronary syndrome and found to have 25% to 50% diameter reduction with coronary computed tomographic angiography (CCTA) are likely to benefit from further diagnostic testing. Methods A registry study of 213 subjects (median age, 51 years; 53% women) with symptoms concerning for possible acute coronary syndrome with low-risk features found to have 25% to 50% maximal diameter stenosis on CCTA was performed at 2 academic medical centers. The analysis was approved by an institutional review board and was conducted with waiver of consent. The potential contribution of additional testing was determined by measuring the major adverse cardiac events (MACEs) from presentation through 30 days. The MACEs included myocardial infarction, coronary revascularization, unstable angina, and cardiovascular death. Sample size calculations were predicated on a 0% MACE rate leading to upper bounds of a 2-sided exact 95% confidence interval less than 2%. Results Thrombolysis in myocardial infarction risk score of less than 2 was present in 92% subjects, 70% (150 of 213) had 2 or more serial cardiac markers performed, and 40% (87 of 213) had stress testing or cardiac catheterization. The MACEs occurred in 1 (0.5%) of 213 subjects (95% confidence interval, 0%-2.6%) and was identified by an elevation of serial cardiac markers during the index hospitalization. No patients experienced cardiovascular death or required revascularization. Conclusions In patients with emergent low-risk chest pain and 25% to 50% diameter coronary stenosis by CCTA, the rate of near-term MACE is very low. Serial cardiac markers may be beneficial in this subgroup. Routine provocative testing is unlikely to be beneficial during the index visit.

This commentary discusses two articles in the current issue of Academic Emergency Medicine that report on investigations of copeptin, a novel biomarker used in conjunction with troponin and an accelerated diagnostic protocol (ADP) in the evaluation of chest pain patients. The authors discuss the challenges and future directions of the evaluation and identification of low-risk chest pain patients who are safe for discharge without additional diagnostic testing.

The use of cardiac magnetic resonance (CMR) imaging has recently been demonstrated to be a useful adjunct in the evaluation of emergency department (ED) patients with acute chest pain. This modality allows the assessment of non-ischemic causes of chest pain, early ischemic changes (T2-weighted imaging for edema), resting and stress perfusion abnormalities, resting and stress wall motion abnormalities, and assessment for scar formation with delayed enhancement. This comprehensive information appears most useful when evaluating higher complexity patients such as those at intermediate or high risk for ACS. In these more complex patients, the use of CMR is supported by appropriateness criteria, and in recent studies appears to be a cost-effective alternative to inpatient evaluation when combined with observation unit care.

Background Patients with low risk chest pain have high utilization of stress testing and cardiac imaging, but low rates of acute coronary syndrome (ACS). The objective of this study was to determine if the HEART score could safely reduce objective cardiac testing in patients with low risk chest pain.

Objectives This study sought to compare the direct cost of medical care and clinical events during the first year after patients with intermediate risk acute chest pain were randomized to stress cardiac magnetic resonance (CMR) observation unit (OU) testing versus inpatient care. Background In a recent study, randomization to OU-CMR reduced median index hospitalization cost compared with the cost of inpatient care in patients presenting to the emergency department with intermediate risk acute chest pain. Methods Emergency department patients with intermediate risk chest pain were randomized to OU-CMR (OU care, cardiac markers, stress CMR) or inpatient care (admission, care per admitting provider). This analysis reports the direct cost of cardiac-related care and clinical outcomes (myocardial infarction, revascularization, cardiovascular death) during the first year of follow-up subsequent to discharge. Consistent with health economics literature, provider cost was calculated from work-related relative value units using the Medicare conversion factor; facility charges were converted to cost using departmental-specific cost-to-charge ratios. Linear models were used to compare cost accumulation among study groups. Results We included 109 randomized subjects in this analysis (52 OU-CMR, 57 inpatient care). The median age was 56 years; baseline characteristics were similar in both groups. At 1 year, 6% of OU-CMR and 9% of inpatient care participants experienced a major cardiac event (p = 0.72) with 1 patient in each group experiencing a cardiac event after discharge. First-year cardiac-related costs were significantly lower for participants randomized to OU-CMR than for participants receiving inpatient care (geometric mean = $3,101 vs. $4,742 including the index visit [p = 0.004] and $29 vs. $152 following discharge [p = 0.012]). During the year following randomization, 6% of OU-CMR and 9% of inpatient care participants experienced a major cardiac event (p = 0.72). Conclusions An OU-CMR strategy reduces cardiac-related costs of medical care during the index visit and over the first year subsequent to discharge, without an observed increase in major cardiac events. (Cost Comparison of Cardiac Magnetic Resonance Imaging [MRI] Use in Emergency Department [ED] Patients With Chest Pain; NCT00678639 )

W. Frank Peacock, Cleveland Clinic Foundation, Cleveland, OH Gregg C. Fonarow, Ahmanson-UCLA Cardiomyopathy Center, David Geffen School of Medicine at UCLA, Los Angeles, CAHeart failure is a leadin...

Objectives: To describe the presenting characteristics and risk stratification of patients presenting to the emergency department with chest pain who have a normal initial troponin level followed by a raised troponin level within 12 h (evolving myocardial infarction (EMI)). Methods: Data from the Internet Tracking Registry for Acute Coronary Syndromes (i*tr ACS ), a registry of patients presenting with undifferentiated chest pain, were used. This analysis included patients without ST segment elevation with at least two troponin assay results ⩽12 h apart. Patients were stratified into three groups: EMI (initial troponin assay negative, second troponin assay positive), non-ST elevation myocardial infarction (NSTEMI) (initial troponin assay positive) and no MI (all troponin assays negative). Results: Of 4136 eligible patients, 5% had EMI, 8% had NSTEMI and 87% had no MI. Patients with EMI were more similar to those with NSTEMI than those with no MI with respect to demographic characteristics, presentation, admission patterns and revascularisation. The initial ECG in patients with EMI was most commonly non-diagnostic (51%), but physicians’ initial impressions commonly reflected MI, unstable angina or high-risk chest pain (76%). This risk assessment was followed by a high rate of critical care admissions (32%) and revascularisation (percutaneous coronary intervention 17%) among patients with EMI. Conclusion: Patients with EMI appear similar at presentation to those with NSTEMI. Patients with EMI are perceived as being at high risk, evidenced by similar diagnostic impressions, admission practices and revascularisation rates to patients with NSTEMI.

ObjectivesTo describe the evaluation and outcomes of elder patients with suspected acute coronary syndromes (ACS) presenting to the emergency department (ED). MethodsThis was a post hoc analysis of the Internet Tracking Registry for Acute Coronary Syndromes (i∗trACS) registry, which had 17,713 ED visits for suspected ACS. First visits from the United States with nonmissing patient demographics, 12-lead electrocardiogram results, and clinical history were included in the analysis. Those who used cocaine or amphetamines or left the ED against medical advice were excluded. Elder was defined as age 75 years or older. ACS was defined by 30-day revascularization, Diagnosis-related Group codes, or death within 30 days with positive cardiac biomarkers at index hospitalization. Multivariable logistic regression analyses were performed to determine the association between being elder and 1) 30-day all-cause mortality, 2) ACS, 3) diagnostic tests ordered, and 4) disposition. Multivariable logistic regression was also performed to determine which clinical variables were associated with ACS in elder and nonelder patients. ResultsA total of 10,126 patients with suspected ACS presenting to the ED were analyzed. For patients presenting to the ED, being elder was independently associated with ACS and all-cause 30-day mortality, with adjusted odds ratios of 1.8 (95% confidence interval [CI] = 1.5 to 2.2) and 2.6 (95% CI = 1.6 to 4.3), respectively. Elder patients were more likely to be admitted to the hospital (adjusted odds ratio, 2.2; 95% CI = 1.8 to 2.6), but there were no differences in the rates of cardiac catheterization and noninvasive stress cardiac imaging. Different clinical variables were associated with ACS in elder and nonelder patients. Chest pain as chief complaint, typical chest pain, and previous history of coronary artery disease were significantly associated with ACS in nonelder patients but were not associated with ACS in elder patients. Male gender and left arm pain were associated with ACS in both elder and nonelder patients. ConclusionsElder patients who present to the ED with suspected ACS represent a population at high risk for ACS and 30-day mortality. Elders are more likely to be admitted to the hospital, but despite an increased risk for adverse events, they have similar odds of receiving a diagnostic test, such as stress cardiac imaging or cardiac catheterization, compared with nonelder patients. Different clinical variables are associated with ACS, and clinical prediction rules utilizing presenting symptoms should consider the effect modification of age.

Objectives Accelerated diagnostic protocols (ADPs), such as the HEART Pathway, are gaining popularity in emergency departments (EDs) as tools used to risk stratify patients with acute chest pain. However, provider nonadherence may threaten the safety and effectiveness of ADPs. The objective of this study was to determine the frequency and impact of ADP nonadherence. Methods A secondary analysis of participants enrolled in the HEART Pathway RCT was conducted. This trial enrolled 282 adult ED patients with symptoms concerning for acute coronary syndrome without ST-elevation on electrocardiogram. Patients randomized to the HEART Pathway (N = 141) were included in this analysis. Outcomes included index visit disposition, nonadherence, and major adverse cardiac events (MACEs) at 30 days. MACE was defined as death, myocardial infarction, or revascularization. Nonadherence was defined as: 1) undertesting—discharging a high-risk patient from the ED without objective testing (stress testing or coronary angiography) or 2) overtesting—admitting or obtaining objective testing on a low-risk patient. Results Nonadherence to the HEART Pathway occurred in 28 of 141 patients (20%, 95% confidence interval [CI] = 14% to 27%). Overtesting occurred in 19 of 141 patients (13.5%, 95% CI = 8% to 19%) and undertesting in nine of 141 patients (6%, 95% CI = 3% to 12%). None of these 28 patients suffered MACE. The net effect of nonadherence was 10 additional admissions among patients identified as low-risk and appropriate for early discharge (absolute decrease in discharge rate of 7%, 95% CI = 3% to 13%). Conclusions Real-time use of the HEART Pathway resulted in a nonadherence rate of 20%, mostly due to overtesting. None of these patients had MACE within 30 days. Nonadherence decreased the discharge rate, attenuating the HEART Pathway's impact on health care use.

Study objective In patients presenting to the emergency department (ED) with an initial diagnostic impression of noncardiac chest pain, we determine the 30-day incidence of adverse cardiac events and characteristics associated with those events. Methods The multicenter, prospectively collected Internet Tracking Registry for Acute Coronary Syndromes (i ∗ tr ACS ) registry of patients with chest pain enrolled from June 1, 1999, to August 1, 2001, was reviewed. We included patients if the physician's initial diagnostic impression was noncardiac chest pain after the medical history, physical examination, and initial 12-lead ECG. ED records, inpatient records, and follow-up results were reviewed for evidence of an adverse cardiac event defined as ST-segment or non–ST-segment elevation myocardial infarction, unstable angina, revascularization, or cardiac death within 30 days. Results Of 17,737 patients enrolled in i ∗ tr ACS , 2,992 had an initial emergency physician impression of noncardiac chest pain. Of these, 85 (2.8%) patients had definite evidence for an adverse cardiac event. The adverse cardiac event group was older (61.2 versus 47.9 years), more likely to be men (58.6% versus 38.7%), and had a higher Acute Cardiac Ischemia–Time Insensitive Predictive Instrument score (26.1 versus 15.6). Factors associated with adverse cardiac events included hypercholesterolemia, diabetes, history of coronary artery disease, and history of congestive heart failure. Conclusion When the initial impression is noncardiac chest pain, high-risk features such as traditional cardiovascular risk factors or a history of coronary artery disease are associated with adverse cardiac events. In the absence of well-defined criteria, treating physicians should consider further evaluation before diagnosing patients with noncardiac chest pain if these features are present.

Improving medical care for patients with chest pain is an intimidating task because of the complexity of the systems used to deliver care. Each step in the delivery of care can be seen as a potential mishap. To improve quality of care, each step in this process needs to be understood, which often

Background: Very-low-risk patients treated in a chest pain observation unit (cPOU) may threaten efficient care delivery. to optimize the efficiency of cPOU evaluations, it is necessary to quantify the avoidable cPOU utilization rate, examine physician variability, and determine patient and physician characteristics associated with avoidable cPOU utilization. Methods: consecutive chest pain patients were evaluated in an emergency Department-based cPOU. Patients were risk stratified based on the american college of cardiology/american Heart association framework, age, and electrocardiogram findings. Very-low-risk was defined as age

Objectives Guidelines recommend that patients presenting to the emergency department (ED) with chest pain who are at low risk for acute coronary syndrome (ACS) receive an objective cardiac evaluation with a stress test or coronary imaging. It is uncertain whether all women derive benefit from this process. The study aim was to determine the incremental value of objective cardiac testing after serial cardiac markers and physician risk assessment. Methods Women enrolled in the 18-site Myeloperoxidase in the Diagnosis of Acute Coronary Syndrome (MIDAS) study had serial troponin I measured at time 0 and 90 minutes and physician risk assessment for the presence of ACS. Risk estimates obtained at the time of ED evaluation were dichotomized as high or non–high risk. The primary outcome was the composite of acute myocardial infarction (AMI) or revascularization at 30 days. Logistic regression with receiver operator characteristic (ROC) curves and net reclassification index were used to determine the diagnostic accuracy for the composite outcome of 30-day MI or revascularization for two models: 1) troponin I results and physician risk assessment alone and 2) troponin I results, physician risk assessment, and objective cardiac testing. Results A total of 460 women with a median age 58 years (interquartile range [IQR] = 48.5 to 68 years) were included, and 32 (6.9%) experienced AMI or revascularization by 30 days. Comparison of the area under the ROC curves (AUC) showed that the addition of objective cardiac testing to the combination of troponin I results and physician risk assessment did not significantly improve prediction of 30-day AMI or revascularization (AUC = 0.85 vs. 0.89; p = 0.053). Using a threshold of 1%, net reclassification index showed that the addition of objective cardiac testing to troponin I results and physician risk assessment worsened the prediction for 30-day AMI and revascularization. All of the reclassified patients were false positives, with nine (2.1%) patients incorrectly reclassified from

The HEART score and North American Chest Pain Rule (NACPR) are decision rules designed to identify acute chest pain patients for early discharge without stress testing or cardiac imaging. This study compares the clinical utility of these decision rules combined with serial troponin determinations.A secondary analysis was conducted of 1005 participants in the Myeloperoxidase In the Diagnosis of Acute coronary syndromes Study (MIDAS). MIDAS is a prospective observational cohort of Emergency Department (ED) patients enrolled from 18 US sites with symptoms suggestive of acute coronary syndrome (ACS). The ability to identify participants for early discharge and the sensitivity for ACS at 30 days were compared among an unstructured assessment, NACPR, and HEART score, each combined with troponin measures at 0 and 3h. ACS, defined as cardiac death, acute myocardial infarction, or unstable angina, occurred in 22% of the cohort. The unstructured assessment identified 13.5% (95% CI 11.5-16%) of participants for early discharge with 98% (95% CI 95-99%) sensitivity for ACS. The NACPR identified 4.4% (95% CI 3-6%) for early discharge with 100% (95% CI 98-100%) sensitivity for ACS. The HEART score identified 20% (95% CI 18-23%) for early discharge with 99% (95% CI 97-100%) sensitivity for ACS. The HEART score had a net reclassification improvement of 10% (95% CI 8-12%) versus unstructured assessment and 19% (95% CI 17-21%) versus NACPR.The HEART score with 0 and 3 hour serial troponin measures identifies a substantial number of patients for early discharge while maintaining high sensitivity for ACS.

Although clear algorithms for diagnosis and treatment of patients with chest pain at low or high risk for an acute coronary syndrome (ACS) exist, they are less well delineated for patients presenting with chest pain with an intermediate risk for ACS. In patients presenting acutely or subacutely to emergency departments (EDs) at high risk for ACS, such as those with ST segment elevation on their 12-lead electrocardiogram (ECG), immediate contrast coronary angiography is performed. On the other hand, chest pain observation units (OUs) are recommended for managing those with chest pain at low risk for an ACS event. In this setting, these OUs are associated with lower healthcare resource utilization and improved cost-effectiveness. Cost-effective diagnosis and treatment options are important goals in healthcare delivery systems. The presentation of patients at intermediate risk for ACS represents an emerging source of resource utilization for EDs. These patients often exhibit pre-existing coronary artery disease, may have sustained prior myocardial infarction, and exhibit multiple comorbidities such as diabetes and hypercholesterolemia. Importantly, however, they will not have evidence of ST elevation on their 12-lead ECG nor will they exhibit serum markers (troponin or creatinine kinase elevations) indicative of ACS. As a consequence of existing co-morbidities, their management becomes time-consuming and may require inpatient monitoring, observation, and cardiac stress testing. Cardiovascular magnetic resonance (CMR) is a powerful tool for risk stratification and prognosis determination in patients in need of stress testing at intermediate risk of ACS. For those who present with acute chest pain syndromes, the combination of CMR in an OU setting represents a potentially attractive option for reducing healthcare-related expenditures without compromising patient outcomes. Recent study results from single centers suggest that CMR-OU care may result in fewer unnecessary hospital admissions and invasive procedures in those presenting with intermediate risk ACS. Further research utilizing stress CMR testing from multiple centers in OU settings is needed to determine if this model of care improves efficiency, reduces healthcare costs, and delivers optimum care in individuals presenting to EDs with chest pain at intermediate risk of ACS.

Background— Among intermediate- to high-risk patients with chest pain, we have shown that a cardiac magnetic resonance (CMR) stress test strategy implemented in an observation unit (OU) reduces 1-year health care costs compared with inpatient care. In this study, we compare 2 OU strategies to determine among lower-risk patients if a mandatory CMR stress test strategy was more effective than a physicians' ability to select a stress test modality. Methods and Results— On emergency department arrival and referral to the OU for management of low- to intermediate-risk chest pain, 120 individuals were randomly assigned to receive (1) a CMR stress imaging test (n=60) or (2) a provider-selected stress test (n=60: stress echo [62%], CMR [32%], cardiac catheterization [3%], nuclear [2%], and coronary CT [2%]). No differences were detected in length of stay (median CMR=24.2 hours versus 23.8 hours, P =0.75), catheterization without revascularization (CMR=0% versus 3%), appropriateness of admission decisions (CMR 87% versus 93%, P =0.36), or 30-day acute coronary syndrome (both 3%). Median cost was higher among those randomly assigned to the CMR-mandated group ($2005 versus $1686, P Conclusions— In patients with lower-risk chest pain receiving emergency department–directed OU care, the ability of a physician to select a cardiac stress imaging modality (including echocardiography, CMR, or radionuclide testing) was more cost-effective than a pathway that mandates a CMR stress test. Contrary to prior observations in individuals with intermediate- to high-risk chest pain, in those with lower-risk chest pain, these results highlight the importance of physician-related choices during acute coronary syndrome diagnostic protocols. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00869245.

This study sought to compare the direct cost of medical care and clinical events during the first year after patients with intermediate risk acute chest pain were randomized to stress cardiac magnetic resonance (CMR) observation unit (OU) testing versus inpatient care.In a recent study, randomization to OU-CMR reduced median index hospitalization cost compared with the cost of inpatient care in patients presenting to the emergency department with intermediate risk acute chest pain.Emergency department patients with intermediate risk chest pain were randomized to OU-CMR (OU care, cardiac markers, stress CMR) or inpatient care (admission, care per admitting provider). This analysis reports the direct cost of cardiac-related care and clinical outcomes (myocardial infarction, revascularization, cardiovascular death) during the first year of follow-up subsequent to discharge. Consistent with health economics literature, provider cost was calculated from work-related relative value units using the Medicare conversion factor; facility charges were converted to cost using departmental-specific cost-to-charge ratios. Linear models were used to compare cost accumulation among study groups.We included 109 randomized subjects in this analysis (52 OU-CMR, 57 inpatient care). The median age was 56 years; baseline characteristics were similar in both groups. At 1 year, 6% of OU-CMR and 9% of inpatient care participants experienced a major cardiac event (p = 0.72) with 1 patient in each group experiencing a cardiac event after discharge. First-year cardiac-related costs were significantly lower for participants randomized to OU-CMR than for participants receiving inpatient care (geometric mean = $3,101 vs. $4,742 including the index visit [p = 0.004] and $29 vs. $152 following discharge [p = 0.012]). During the year following randomization, 6% of OU-CMR and 9% of inpatient care participants experienced a major cardiac event (p = 0.72).An OU-CMR strategy reduces cardiac-related costs of medical care during the index visit and over the first year subsequent to discharge, without an observed increase in major cardiac events. (Cost Comparison of Cardiac Magnetic Resonance Imaging [MRI] Use in Emergency Department [ED] Patients With Chest Pain; NCT00678639).

Objectives: Most contemporary cardiac risk stratification tools have been derived and validated in mixed-race populations. Their validity in single-race populations has not been tested. The authors sought to compare the performance of a risk stratification tool between a mixed-race U.S. patient population and an Asian patient population. Methods: This study is an analysis of data from the Internet Tracking Registry for Acute Coronary Syndromes (i*trACS) registry of patients with chest pain presenting to the emergency departments of eight U.S. centers and one site in Singapore. The Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI) was computed for included patients, and its performance in predicting acute coronary syndrome (ACS) was compared between patients from the United States and Singapore. Results: Of the 11,991 included patients, 1,120 experienced ACS. Although the ACI-TIPI demonstrated similar accuracy among groups (area under the curve, 0.729 [U.S.] vs. 0.719 [Singapore]; p = 0.5611), sensitivity and specificity were different when equal ACI-TIPI thresholds were considered. Recreating the logistic regression models used to create the ACI-TIPI showed similar results between the derived parameters and the parameters estimated for the U.S. group. In contrast, age older than 50 years (log-odds ratio [LOR], 0.107; 95% confidence interval [CI] = 0.518 to 0.713), male gender (LOR, 0.487; 95% CI = 0.149 to 1.122), and chest pain as a primary complaint (LOR, 0.237; 95% CI = 0.139 to 0.613) had little predictive power in patients from Singapore. Conclusions: Differences exist in presentation and factors associated with ACS among patients from the United States and Singapore that may affect the performance of risk stratification tools. These findings suggest that cardiac clinical decision rules need international validation.

Objectives: The authors analyzed contemporary use of glycoprotein (GP) IIb/IIIa inhibitors in patients with non– ST-segment elevation acute coronary syndrome (NSTE ACS) to determine patient selection patterns with early (,24 hours) GP IIb/IIIa inhibitor use and the relationship between GP IIb/IIIa inhibitor therapy and use of other guidelines-recommended therapies for NSTE ACS. Methods: Using the CRUSADE Quality Improvement Initiative database, patient characteristics, in-hospital treatments, and outcomes for 65,424 patients with ischemic chest pain of ,24 hours’ duration and either positive cardiac markers or ischemic electrocardiographic changes were analyzed. Data were collected from 443 U.S. hospitals from January 2001 to June 2003. Results: Only 35% of eligible patients received GP IIb/IIIa inhibitors ,24 hours after hospital admission. Approximately one third of patients received GP IIb/IIIa inhibitors in the emergency department, one third in the coronary care unit, and one third in the catheterization laboratory. Admission to a cardiologist’s care was the most significant associated factor with early GP IIb/IIIa inhibitor use, along with elevated cardiac markers or ST-segment deviation. Patients at high risk for adverse cardiac events due to advanced age, congestive heart failure, or female gender were less likely to receive early GP IIb/IIIa inhibitor therapy. Patients who received early GP IIb/IIIa inhibitor therapy were more likely to receive other guidelinesrecommended therapies. Conclusions: Despite the American College of Cardiology/American Heart Association (ACC/AHA) guidelines recommendations, early GP IIb/ IIIa inhibitor therapy remains underutilized in patients with NSTE ACS and administration of early GP IIb/IIIa inhibitors is directed toward lower-risk patients. Early GP IIb/IIIa inhibitor therapy is associated with improved overall adherence to the ACC/AHA guidelines. Key words: glycoprotein IIb/IIIa inhibitors; non–ST-segment elevation acute coronary syndrome; guidelines-recommended therapies. ACADEMIC EMERGENCY MEDICINE 2005; 12: 431–438.