Cost analysis of the History, ECG, Age, Risk factors, and initial Troponin (HEART) Pathway randomized control trial.

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.

Impact of anticoagulation regimen prior to revascularization in patients with non-ST-segment elevation acute coronary syndromes: The ACUITY trial.

AIM: To evaluate the impact of antithrombotic regimens during the medical phase of treatment among 13,819 patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) treated with an early invasive strategy in the acute catheterization and urgent intervention triage strategy (ACUITY) trial. METHODS AND RESULTS: Endpoints included composite major adverse cardiac events (MACE), major bleeding, and net adverse clinical events (NACE; MACE or major bleeding). The median (interquartile range) duration of antithrombin use in the medical only treatment phase was 6.5 (1.8-22.5) hours. MACE, major bleeding, and NACE during the medical only phase occurred in 63 (0.5%), 117 (0.9%), and 178 (1.3%) patients, respectively. MACE rates in the medical-treatment-only phase were not significantly different between the four randomized medical regimens used (heparin alone, bivalirudin alone, heparin plus a glycoprotein IIb/IIIa inhibitor [GPI], and bivalirudin plus GPI) (Ptrend = 0.65). The lowest rates of major bleeding and NACE during the medical treatment phase occurred in patients treated with bivalirudin alone (Ptrend = 0.0006 and Ptrend = 0.0004, respectively). CONCLUSIONS: In patients with NSTE-ACS undergoing an early invasive strategy, treatment with bivalirudin alone significantly reduced major bleeding and improved net clinical outcomes during the upstream medical management phase with comparable rates of MACE. © 2015 Wiley Periodicals, Inc.

The time dependence of antithrombin initiation in patients with non-ST-segment elevation acute coronary syndromes: subgroup analysis from the ACUITY trial.

STUDY OBJECTIVE: Antithrombins are among standard treatment agents for patients with non-ST-segment elevation acute coronary syndromes. We aimed to determine the association between time from emergency department (ED) presentation to treatment with an antithrombin and adverse cardiac events. METHODS: The study cohort was a subgroup of the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial, enrolled from March 1, 2005, to December 5, 2005. The ACUITY trial enrolled patients with moderate- and high-risk non-ST-segment elevation acute coronary syndromes and who were undergoing an early invasive strategy (<72 hours from randomization). All patients received an antithrombin (unfractionated heparin, low-molecular-weight heparin, or bivalirudin), in addition to other agents. A formal ED case report form was introduced in March 2005. Time from presentation to antithrombin initiation was evaluated as a continuous variable in hours. The endpoints were defined as major ischemic events (death, myocardial infarction, unplanned revascularization) or major bleeding within 30 days, or inhospital major bleeding. Logistic regression was used to adjust for demographics, severity of disease, comorbidities, and treatment differences. RESULTS: Of the 2,722 patients enrolled with an ED case report form, complete time data were available in 2,632 (96%). Median time to antithrombin administration was 4.87 hours (interquartile range 2.67 to 9.83). After multivariable analysis, there was no association of major ischemic events with log time (hours) to antithrombin treatment (adjusted odds ratio [OR] 0.99; 95% confidence interval [CI] 0.97 to 1.01). There was an increase in major bleeding at 30 days and inhospital major bleeding complications with longer log time (hours) to antithrombin initiation (adjusted OR 1.44, 95% CI 1.15 to 1.80; OR 1.43, 95% CI 1.13 to 1.83, respectively). CONCLUSION: In this study of patients with non-ST-segment elevation acute coronary syndromes who were undergoing an early invasive management strategy, we were unable to demonstrate an association between adverse ischemic outcomes with the timing of antithrombin administration. However, there was an increase in bleeding outcomes as time to antithrombin administration increased.

Stress cardiac magnetic resonance imaging with observation unit care reduces cost for patients with emergent chest pain: a randomized trial.

STUDY OBJECTIVE: We determine whether imaging with cardiac magnetic resonance imaging (MRI) in an observation unit would reduce medical costs among patients with emergent non-low-risk chest pain who otherwise would be managed with an inpatient care strategy. METHODS: Emergency department patients (n=110) at intermediate or high probability for acute coronary syndrome without electrocardiographic or biomarker evidence of a myocardial infarction provided consent and were randomized to stress cardiac MRI in an observation unit versus standard inpatient care. The primary outcome was direct hospital cost calculated as the sum of hospital and provider costs. Estimated median cost differences (Hodges-Lehmann) and distribution-free 95% confidence intervals (Moses) were used to compare groups. RESULTS: There were 110 participants with 53 randomized to cardiac MRI and 57 to inpatient care; 8 of 110 (7%) experienced acute coronary syndrome. In the MRI pathway, 49 of 53 underwent stress cardiac MRI, 11 of 53 were admitted, 1 left against medical advice, 41 were discharged, and 2 had acute coronary syndrome. In the inpatient care pathway, 39 of 57 patients initially received stress testing, 54 of 57 were admitted, 3 left against medical advice, and 6 had acute coronary syndrome. At 30 days, no subjects in either group experienced acute coronary syndrome after discharge. The cardiac MRI group had a reduced median hospitalization cost (Hodges-Lehmann estimate $588; 95% confidence interval $336 to $811); 79% were managed without hospital admission. CONCLUSION: Compared with inpatient care, an observation unit strategy involving stress cardiac MRI reduced incident cost without any cases of missed acute coronary syndrome in patients with emergent chest pain.

Acute detection of ST-elevation myocardial infarction missed on standard 12-Lead ECG with a novel 80-lead real-time digital body surface map: primary results from the multicenter OCCULT MI trial.

STUDY OBJECTIVE: Although 80-lead ECG body surface mapping is more sensitive for ST-elevation myocardial infarction (STEMI) than the 12-lead ECG, its clinical utility in chest pain in the emergency department (ED) has not been studied. We sought to determine the prevalence, clinical care patterns, and clinical outcomes of patients with STEMI identified on 80-lead but not on 12-lead (80-lead-only STEMI). METHODS: The Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction trial was a multicenter prospective observational study of moderate- to high-risk chest pain patients presenting to the ED. Patients received simultaneous 12-lead and 80-lead ECGs as part of their initial evaluation and were treated according to the standard of care, with clinicians blinded to the 80-lead results. The primary outcome of the trial was door-to-sheath time in patients with 80-lead-only STEMI versus patients with STEMI identified by 12-lead alone (12-lead STEMI). Secondary outcomes included angiographic and clinical outcomes at 30 days. RESULTS: One thousand eight hundred thirty patients were evaluated, 91 had a discharge diagnosis of 12-lead STEMI, and 25 patients met criteria for 80-lead-only STEMI. Eighty-four of the 91 12-lead STEMI patients underwent cardiac catheterization, with a median door-to-sheath time of 54 minutes, versus 14 of the 25 80-lead-only STEMI patients, with a door-to-sheath time of 1,002 minutes (estimated treatment difference in median=881; 95% confidence interval 181 to 1,079 minutes). Clinical outcomes and revascularization rates, however, were similar between 80-lead-only STEMI and 12-lead STEMI patients. CONCLUSION: The 80-lead ECG provides an incremental 27.5% increase in STEMI detection versus the 12-lead. Patients with 80-lead-only STEMI have adverse outcomes similar to those of 12-lead STEMI patients but are treated with delayed or conservative invasive strategies.

Glycoprotein IIb-IIIa inhibitors in the emergency department for patients with non-ST-elevation acute coronary syndromes: principles and practices.

Non-ST-elevation acute coronary syndrome is associated with significant morbidity and mortality. Although the benefit of platelet inhibition by glycoprotein (GP) IIb-IIIa inhibitors in patients undergoing percutaneous coronary intervention (PCI) is well established, emergency physicians and cardiologists have different perspectives regarding their optimum administration, especially upstream before PCI. In this article, two emergency physicians and two cardiologists analyze data and discuss relevant issues, including the ischemic benefits vs. the risk of bleeding associated with GP IIb-IIIa inhibitors in appropriate patients, for example, those with an elevated troponin level or who undergo revascularization. The emergency physicians support early identification of high-risk non-ST-elevation acute coronary syndrome patients and early administration of GP IIb-IIIa inhibitors, which are linked to improved patient outcomes. The cardiologists emphasize risk stratification to identify patients in whom the expected reduction in ischemic complications outweighs the risk of increased bleeding with these agents. GP IIb-IIIa inhibitors should be considered in patients with unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI) in whom PCI is planned, especially those with high-risk features or elevated serum troponin levels. It is reasonable to start this treatment upstream of intervention, pending further studies investigating the optimal timing of initiation of therapy in appropriate patients.

The HEART Pathway Randomized Controlled Trial One-year Outcomes.

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.

Coronary artery bypass surgery in patients with acute coronary syndromes is difficult to predict.

BACKGROUND: Although the use of clopidogrel in patients "unlikely" to require coronary artery bypass grafting (CABG) is recommended in current guidelines of acute coronary syndrome (ACS) management, an important minority of patients require CABG. We assessed the ability to predict need for CABG from demographics known at the time of ACS presentation, using data from SYNERGY. METHODS: Patients undergoing CABG at any time after the index angiogram were included. Early CABG was defined as surgery <72 hours after angiography. The relationship between cessation of enoxaparin and glycoprotein IIb/IIIa inhibition, CABG timing, and 30-day death or MI and bleeding events was assessed. Demographic and clinical factors and geographic location were assessed as predictors of early CABG or CABG at any time. The discriminatory utility is reported with the c-index. RESULTS: Of the 9053 patients undergoing angiography, 1793 (18.1%) received CABG. Early CABG (n = 972) was associated with more bleeding events (39.2% vs 29.4%, P < .001) but not death or MI. The risk of bleeding events diminished when surgery was delayed >18 hours after cessation of enoxaparin and glycoprotein IIb/IIIa inhibition. Clinical factors associated with early CABG included diabetes and lack of prior CABG or clopidogrel. However, overall the logistic regression model had poor discriminatory ability to predict patients likely to require CABG in the setting of an ACS presentation (c-index 0.671). CONCLUSIONS: It is difficult to predict those high-risk patients with ACS who will undergo surgical revascularization based on baseline clinical characteristics.

Heart failure with preserved left ventricular systolic function among patients with non-ST-segment elevation acute coronary syndromes.

Previous studies of non-ST-segment elevation acute coronary syndromes (NSTE ACSs) complicated by heart failure (HF) have focused primarily on patients with left ventricular systolic dysfunction defined by an ejection fraction (EF) <40%. Little is known about HF with preserved systolic function (EF > or =40%) in the NSTE ACS population. We identified high-risk patients with NSTE ACS (ischemic electrocardiographic changes and/or positive cardiac markers) from the CRUSADE quality improvement initiative who had an EF recorded and who had information on HF status. Management and outcomes were analyzed and compared based on the presence or absence of HF and whether left ventricular EF was > or =40%. Of 94,558 patients with NSTE ACS, 21,561 (22.8%) presented with signs of HF, and most had HF with preserved systolic function (n = 11,860, 55%). Mortality rates were 10.7% for HF/systolic dysfunction, 5.8% for HF/preserved systolic function, 5.7% for no HF/systolic dysfunction, and 1.5% for no HF/preserved systolic function. Use of guideline-recommended medical therapies and interventions was frequently significantly lower in those with HF regardless of EF compared with those without HF, except for use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. In conclusion, NSTE ACS complicated by HF with preserved systolic function is common and associated with a 2.3-fold higher mortality compared with NSTE ACS without HF or systolic dysfunction. Guideline-recommended therapies and interventions are under-utilized in patients with NSTE ACS and HF, with and without preserved systolic function, compared with those without HF.

Timing of glycoprotein IIb/IIIa inhibitor use and outcomes among patients with non-ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention (results from CRUSADE).

Although glycoprotein (GP) IIb/IIIa inhibitors are recommended for patients with unstable angina and non-ST-segment elevation myocardial infarction who undergo percutaneous coronary intervention (PCI), the American College of Cardiology/American Heart Association guidelines do not specify optimal timing for their initiation. We compared patient characteristics and clinical outcomes in 30,830 patients with non-ST-segment elevation myocardial infarction included in the CRUSADE initiative (January 2001 to December 2004) who underwent PCI with upstream (>1 hour before PCI) or periprocedural use of GP IIb/IIIa inhibitors. GP IIb/IIIa inhibitors were administered upstream in 43% of patients versus periprocedurally in 57%. Time from arrival to PCI was longer for patients who received GP IIb/IIIa inhibitors upstream (median 25.6 hours) compared with periprocedurally (18.2 hours). Unadjusted incidence of in-hospital death or reinfarction was lower with upstream GP IIb/IIIa inhibitor use (3.8% vs 4.3%, p = 0.046), but after adjusting for patient and hospital characteristics, this difference was not statistically significant. Treatment with upstream GP IIb/IIIa inhibitors was associated with a lower incidence of unadjusted death or reinfarction in patients who underwent PCI <12 hours from hospital arrival. In conclusion, in this observational analysis, overall ischemic outcomes were similar between the 2 groups, but clinical trials are needed to solve the controversy over optional timing of GP IIb/IIIa inhibitor use.

The role of cardiac risk factor burden in diagnosing acute coronary syndromes in the emergency department setting.

STUDY OBJECTIVE: We seek to determine whether cardiac risk factor burden (defined as the number of conventional cardiac risk factors present) is useful for the diagnosis of acute coronary syndromes in the emergency department (ED) setting. METHODS: This was a post hoc analysis of the Internet Tracking Registry of Acute Coronary Syndromes (i*trACS) registry, which had 17,713 ED visits for suspected acute coronary syndromes. First visit for US patients who were not cocaine or amphetamine users, who did not leave against medical advice, and for whom ECG and demographic data were complete were included. Acute coronary syndrome was defined by 30-day revascularization, diagnostic-related group codes, or death within 30 days, with positive cardiac biomarkers at index hospitalization. Cardiac risk factors were diabetes, hypertension, smoking, hypercholesterolemia, and family history of coronary artery disease. Cardiac risk factor burden was defined as the number of risk factors present. Because multiple logistic regression analysis revealed that age modified the relationship between cardiac risk factor burden and acute coronary syndromes, a stratified analysis was performed for 3 age categories: younger than 40, 40 to 65, and older than 65 years. Positive likelihood ratios and negative likelihood ratios with their 95% confidence intervals (CIs) were calculated for each total risk factor cutoff. RESULTS: Of 10,806 eligible patients, 871 (8.1%) had acute coronary syndromes. In patients younger than 40 years, having no risk factors had a negative likelihood ratio of 0.17 (95% CI 0.04 to 0.66), and having 4 or more risk factors had a positive likelihood ratio of 7.39 (95% CI 3.09 to 17.67). In patients between 40 and 65 years of age, having no risk factors had a negative likelihood ratio of 0.53 (95% CI 0.40 to 0.71), and having 4 or more risk factors had a positive likelihood ratio of 2.13 (95% CI 1.66 to 2.73). In patients older than 65 years, having no risk factors had a negative likelihood ratio of 0.96 (95% CI 0.74 to 1.23), and having 4 or more risk factors had a positive likelihood ratio of 1.09 (95% CI 0.64 to 1.62). CONCLUSION: Cardiac risk factor burden has limited clinical value in diagnosing acute coronary syndromes in the ED setting, especially in patients older than 40 years.

Implementation of a statewide system for coronary reperfusion for ST-segment elevation myocardial infarction.

CONTEXT: Despite 2 decades of evidence demonstrating benefits from prompt coronary reperfusion, registries continue to show that many patients with ST-segment elevation myocardial infarction (STEMI) are treated too slowly or not at all. OBJECTIVE: To establish a statewide system for reperfusion, as exists for trauma care, to overcome systematic barriers. DESIGN AND SETTING: A quality improvement study that examined the change in speed and rate of coronary reperfusion after system implementation in 5 regions in North Carolina involving 65 hospitals and associated emergency medical systems (10 percutaneous coronary intervention [PCI] hospitals and 55 non-PCI hospitals). PATIENTS: A total of 1164 patients with STEMI (579 preintervention and 585 postintervention) eligible for reperfusion were treated at PCI hospitals (median age 61 years, 31% women, 4% Killip class III or IV). A total of 925 patients with STEMI (518 preintervention and 407 postintervention) were treated at non-PCI hospitals (median age 62 years, 32% women, 4% Killip class III or IV). INTERVENTIONS: Early diagnosis and the most expedient coronary reperfusion method at each point of care: emergency medical systems, emergency department, catheterization laboratory, and transfer. Within 5 regions, PCI hospitals agreed to provide single-call catheterization laboratory activation by emergency medical personnel, accept patients regardless of bed availability, and improve STEMI care for the entire region regardless of hospital affiliation. MAIN OUTCOME MEASURES: Reperfusion times and rates 3 months before (July to September 2005) and 3 months after (January to March 2007) a year-long implementation. RESULTS: Median reperfusion times significantly improved according to first door-to-device (presenting to PCI hospital 85 to 74 minutes, P < .001; transferred to PCI hospital 165 to 128 minutes, P < .001), door-to-needle in non-PCI hospitals (35 to 29 minutes, P = .002), and door-in to door-out for patients transferred from non-PCI hospitals (120 to 71 minutes, P < .001). Nonreperfusion rates were unchanged (15%) in non-PCI hospitals and decreased from 23% to 11% in the PCI hospitals. For patients presenting to or transferred to PCI hospitals, clinical outcomes including death, cardiac arrest, and cardiogenic shock did not significantly change following the intervention. CONCLUSIONS: A statewide program focused on regional systems for reperfusion for STEMI can significantly improve quality of care. Further research is needed to ensure that programs that result in improved application of reperfusion treatments will lead to reductions in mortality and morbidity from STEMI.

Validation of the No Objective Testing Rule and Comparison to the HEART Pathway.

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.

Use of the HEART Pathway with high sensitivity cardiac troponins: A secondary analysis.

OBJECTIVES: The HEART Pathway combines a decision aid and serial contemporary cardiac troponin I (cTnI) measures to achieve >99% sensitivity for major adverse cardiac events (MACE) at 30days and early discharge rates >20%. However, the impact of integrating high-sensitivity troponin (hs-cTn) measures into the HEART Pathway has yet to be determined. In this analysis we compare test characteristics of the HEART Pathway using hs-cTnI, hs-cTnT, or cTnI. DESIGN & METHODS: A secondary analysis of participants enrolled in the HEART Pathway RCT was conducted. Each patient was risk stratified by the cTn-HEART Pathway (Siemens TnI-Ultra at 0- and 3-h) and a hs-cTn-HEART Pathway using hs-cTnI (Abbott) or hs-cTnT (Roche) at 3-h. The early discharge rate, sensitivity, specificity, and negative predictive value (NPV) for MACE (death, myocardial infarction, or coronary revascularization) at 30days were calculated. RESULTS: hs-cTnI measures were available on 133 patients. MACE occurred in 11/133 (8%) of these patients. Test characteristics for the HEART Pathway using serial cTnI vs 3hour hs-cTnI were the same: sensitivity (100%, 95%CI: 72-100%), specificity (49%, 95%CI: 40-58%), NPV (100%, 95%CI: 94-100%), and early discharge rate (45%, 95%CI: 37-54%). The HEART Pathway using hs-cTnT missed one MACE event (myocardial infarction): sensitivity (91%, 95%CI: 59-100%), specificity (48%, 95%CI: 39-57%), NPV (98%, 95%CI: 91-100%), and early discharge rate (45%, 95%CI: 37-54%). CONCLUSIONS: There was no difference in the test characteristics of the HEART Pathway whether using cTnI or hs-cTnI, with both achieving 100% sensitivity and NPV. Use of hs-cTnT with the HEART Pathway was associated with one missed MACE.

The impact of emergency department structure and care processes in delivering care for non-ST-segment elevation acute coronary syndromes.

BACKGROUND: We sought to assess the influence of emergency department (ED) structure and care processes on adherence to practice guidelines for the treatment of patients with non-ST-segment elevation acute coronary syndromes. METHODS: We surveyed emergency physicians and nurses from 316 hospitals participating in the CRUSADE Quality Improvement Initiative and used multivariable modeling to correlate ED-specific characteristics with guidelines adherence. RESULTS: Factors that were significantly associated with improved guidelines adherence included collaboration between emergency physicians and hospital administration, northeast region, adequate nursing support, use of locum tenens physicians, an independent ED (not a division of another clinical department), and use of a care algorithm for acute coronary syndromes. CONCLUSIONS: Quality improvement strategies that have the full support of hospital administration, focus on increasing collaboration between emergency physicians and other health care providers, and specified protocol-driven management algorithm may be the most successful methods for improving the care and outcomes of patients with non-ST-segment elevation acute coronary syndromes.

Discordant cardiac biomarkers: frequency and outcomes in emergency department patients with chest pain.

STUDY OBJECTIVE: We evaluate associations between pairs of discordant cardiac biomarkers (positive MB band of creatine kinase [CKMB] with negative creatine kinase, positive CKMB with negative cardiac troponin, and positive troponin with negative CKMB) and the presence of acute coronary syndromes in emergency department (ED) chest pain patients. METHODS: This was a secondary analysis of a prospective registry. Data were obtained from the multicenter Internet Tracking Registry of Acute Coronary Syndromes, which included 17,713 ED visits for possible acute coronary syndrome between June 1999 and August 2001. First visits and first ED cardiac biomarker results from the 9 sites, 8 in the United States and 1 in Singapore, were included. Subjects were excluded for incomplete information or an initial ECG consistent with ST-segment elevation myocardial infarction. Acute coronary syndrome was defined by diagnosis-related group code indicating myocardial infarction, positive invasive or noninvasive diagnostic testing, revascularization, or death during hospitalization or within 30 days. RESULTS: Of 8,769 eligible patients, 1,614 (18.4%) had acute coronary syndrome. The CKMB and cardiac troponin results were discordant in 7% of patients (CKMB+/cardiac troponin-, 4.9%, CKMB-/cardiac troponin+ 2.1%), whereas increased CKMB with normal creatine kinase levels occurred in 239 (3.1%) patients. The unadjusted odds ratios with 95% confidence intervals for acute coronary syndrome in patients with and without discordant markers were: CKMB+/CK- 5.7 (4.4-7.4), CKMB+/CK+ 4.4 (3.6-5.2), CKMB-/cTn+ 4.8 (3.4-6.8), CKMB+/cTn- 2.2 (1.7-2.8), CKMB+/cTn+ 26.6 (18.0-39.3). For the group with cardiac troponin, the reference category was negative troponin and negative CKMB; for the group with creatine kinase, the reference category was negative CKMB but either a positive or negative creatine kinase. CONCLUSION: Among the spectrum of ED patients with chest pain, an increased CKMB level with a normal creatine kinase level identifies patients at increased risk for acute coronary syndrome. Similarly, an increased troponin level regardless of CKMB level and an increased CKMB level regardless of troponin level identify patients at higher risk for acute coronary syndrome than those with uniformly normal cardiac biomarker levels. Our data suggest that discordant cardiac biomarkers may identify patients at increased risk for acute coronary syndrome.

The Internet Tracking Registry of Acute Coronary Syndromes (i*trACS): a multicenter registry of patients with suspicion of acute coronary syndromes reported using the standardized reporting guidelines for emergency department chest pain studies.

STUDY OBJECTIVE: Observational studies of well-described patient populations presenting to emergency departments (EDs) with suspicion of acute coronary syndrome are necessary to understand the relationships between patients' signs and symptoms, cardiac risk profile, test results, practice patterns, and outcomes. We describe the methods for data collection and the ED population enrolled in a multicenter registry of patients with chest pain. METHODS: Patients older than 18 years, presenting to one of 8 EDs in the United States or 1 ED in Singapore, and with possible acute coronary syndrome were enrolled in the Internet Tracking Registry of Acute Coronary Syndromes between June 1999 and August 2001. Prospective data, including presenting signs and symptoms, ECG findings, and the ED physician's initial impression of risk, were systematically collected. Medical record review or daily follow-up was used to obtain cardiac biomarker results, invasive and noninvasive testing, treatments, procedures, and inhospital outcomes. Thirty-day outcomes were determined by telephone follow-up and medical record review. RESULTS: The registry includes 15,608 patients, with 17,713 visits. Chest pain was the chief complaint in 71% of visits. The ECG was diagnostic of ischemia or infarction in 10.1% and positive cardiac biomarkers were observed in 10% of visits. Forty-three percent of patients were sent home directly from the ED. Of admitted patients, 5% died by 30 days, and 3% had documented coronary artery disease or had undergone percutaneous coronary intervention or coronary artery bypass grafting within 30 days. For patients discharged directly from the ED, 0.4% died or had a documented myocardial infarction within 30 days. Coronary artery bypass graft surgery, percutaneous coronary intervention, or a diagnosis of coronary artery disease was found in 0.5% of discharged patients. CONCLUSION: A unique description of undifferentiated ED chest pain patients with suspected acute coronary syndrome is provided. The data set can be used to generate and explore hypotheses to improve understanding of the complex relationships between presentation, treatment, testing, intervention and outcomes.

Relationship between risk stratification by cardiac troponin level and adherence to guidelines for non-ST-segment elevation acute coronary syndromes.

BACKGROUND: The threshold of troponin elevation that stimulates changes in clinical decision making for patients with non-ST-segment elevation acute coronary syndromes (NSTE ACSs) has not been previously evaluated. METHODS: A total of 23 298 patients with NSTE ACSs from the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines) initiative were separated into categories of maximum troponin ratios (ratio of the highest recorded troponin value in the first 24 hours to the local laboratory troponin assay upper limit of normalization [ULN]). RESULTS: Unadjusted rates of in-hospital mortality increased from the group with troponin levels below the reference limit (maximum troponin ratio 0-1 x ULN; n = 5291) to those with minor (1-2 x ULN; n = 2499), intermediate (2-5 x ULN; n = 3825), and major (>5 x ULN; n = 11 683) elevations (-2.8% vs 4.6% vs 4.7% vs 6.0%). The use of early (<24 hours) aspirin, heparin, glycoprotein IIb/IIIa inhibitors, and beta-blockers was similar for the group with troponin levels below the reference limit compared with those with minor troponin elevations, and greater use of medications was demonstrated in patients with intermediate and major troponin elevations. Use of cardiac catheterization and percutaneous coronary intervention was higher in patients with troponin levels below the reference limit compared with those with minor troponin elevations, and procedures were used most frequently in patients with major troponin elevations. Similar patterns of care were demonstrated after excluding patients with chronic renal insufficiency. CONCLUSIONS: Any degree of troponin elevation is associated with a higher risk of mortality for patients with NSTE ACSs, but guideline-recommended medical therapies are used more commonly only in patients with intermediate and major troponin elevations, whereas patients with troponin levels below the reference limit underwent invasive procedures more frequently than those with mild troponin elevations.

Comparison of the HEART and TIMI Risk Scores for Suspected Acute Coronary Syndrome in the Emergency Department.

OBJECTIVES: The emergency department evaluation for suspected acute coronary syndrome (ACS) is common, costly, and challenging. Risk scores may help standardize clinical care and screening for research studies. The Thrombolysis in Myocardial Infarction (TIMI) and HEART are two commonly cited risk scores. We tested the null hypothesis that the TIMI and HEART risk scores have equivalent test characteristics. METHODS: We analyzed data from the Internet Tracking Registry of Acute Coronary Syndromes (i*trACS) from 9 EDs on patients with suspected ACS, 1999-2001. We excluded patients with an emergency department diagnosis consistent with ACS, or without sufficient data to calculate TIMI and HEART scores. The primary outcome was 30-day major adverse cardiovascular events, including all-cause death, acute myocardial infarction, and urgent revascularization. We describe test characteristics of the TIMI and HEART risk scores. RESULTS: The study cohort included 8255 patients with 508 (6.2%) 30-day major adverse cardiovascular events. Receiver operating curve and reclassification analyses favored HEART [c statistic: 0.753, 95% confidence interval (CI): 0.733-0.773; continuous net reclassification improvement: 0.608, 95% CI: 0.527-0.689] over TIMI (c statistic: 0.678, 95% CI: 0.655-0.702). A HEART score 0-3 [negative predictive value (NPV) 0.982, 95% CI: 0.978-0.986; positive predictive value (PPV) 0.103, 95% CI: 0.094-0.113; likelihood ratio (LR) positive 1.76; LR negative 0.28] demonstrates similar or superior NPV/PPV/LR compared with TIMI = 0 (NPV 0.978, 95% CI: 0.971-0.983; PPV 0.077, 95% CI: 0.071-0.084; LR positive 1.28; LR negative 0.35) and TIMI = 0-1 (NPV 0.963, 95% CI: 0.958-0.968; PPV 0.102, 95% CI: 0.092-0.113; LR positive 1.73; LR negative 0.58). CONCLUSIONS: The HEART score has better discrimination than TIMI and outperforms TIMI within previously published "low-risk" categories.

Association of Early Stress Testing with Outcomes for Emergency Department Evaluation of Suspected Acute Coronary Syndrome.

BACKGROUND: Professional society guidelines suggest early stress testing (within 72 hours) after an emergency department (ED) evaluation for suspected acute coronary syndrome (ACS). However, there is increasing concern that current practice results in over-testing without evidence of benefit. We test the hypothesis that early stress testing improves outcomes. METHODS: We analyzed prospectively collected data from 9 EDs on patients with suspected ACS, 1999-2001. We excluded patients with an ED diagnosis of ACS. The primary outcome was 30-day major adverse cardiac events (MACEs), including all-cause death, acute myocardial infarction, and revascularization. We used the HEART score to determine pretest ACS risk (low, intermediate, and high). To mitigate potential confounding, patients with and without early stress testing were matched within pretest risk strata in a 1:2 ratio using propensity scores. RESULTS: Of 7127 potentially eligible patients, 895 (13%) received early stress testing. The analytic cohort included 895 patients with early stress testing matched to 1790 without early stress testing. The overall 30-day MACE rate in both the source and analytic population was 3%. There were no baseline imbalances after propensity score matching (P > 0.1 for more than 30 variables). There was no association between early stress testing and 30-day MACE [odds ratio, 1.0; 95% confidence interval (CI), 0.6-1.7]. There was no effect modification by pretest risk (low: odds ratio, 1.0; 95% CI, 0.2-3.7; intermediate: 1.2; 95% CI, 0.6-2.6; high: 0.4; 95% CI, 0.1-1.6). CONCLUSIONS: Early stress testing is not associated with reduced MACE in patients evaluated for suspected ACS. Early stress testing may have limited value in populations with low MACE rate.