Chadwick D. Miller

CT Angiography for Safe Discharge of Patients with Possible Acute Coronary Syndromes

BACKGROUND Admission rates among patients presenting to emergency departments with possible acute coronary syndromes are high, although for most of these patients, the symptoms are ultimately found not to have a cardiac cause. Coronary computed tomographic angiography (CCTA) has a very high negative predictive value for the detection of coronary disease, but its usefulness in determining whether discharge of patients from the emergency department is safe is not well established. METHODS We randomly assigned low-to-intermediate-risk patients presenting with possible acute coronary syndromes, in a 2:1 ratio, to undergo CCTA or to receive traditional care. Patients were enrolled at five centers in the United States. Patients older than 30 years of age with a Thrombolysis in Myocardial Infarction risk score of 0 to 2 and signs or symptoms warranting admission or testing were eligible. The primary outcome was safety, assessed in the subgroup of patients with a negative CCTA examination, with safety defined as the absence of myocardial infarction and cardiac death during the first 30 days after presentation. RESULTS We enrolled 1370 subjects: 908 in the CCTA group and 462 in the group receiving traditional care. The baseline characteristics were similar in the two groups. Of 640 patients with a negative CCTA examination, none died or had a myocardial infarction within 30 days (0%; 95% confidence interval [CI], 0 to 0.57). As compared with patients receiving traditional care, patients in the CCTA group had a higher rate of discharge from the emergency department (49.6% vs. 22.7%; difference, 26.8 percentage points; 95% CI, 21.4 to 32.2), a shorter length of stay (median, 18.0 hours vs. 24.8 hours; P<0.001), and a higher rate of detection of coronary disease (9.0% vs. 3.5%; difference, 5.6 percentage points; 95% CI, 0 to 11.2). There was one serious adverse event in each group. CONCLUSIONS A CCTA-based strategy for low-to-intermediate-risk patients presenting with a possible acute coronary syndrome appears to allow the safe, expedited discharge from the emergency department of many patients who would otherwise be admitted. (Funded by the Commonwealth of Pennsylvania Department of Health and the American College of Radiology Imaging Network Foundation; ClinicalTrials.gov number, NCT00933400.).

Clinical Characteristics, Management, and Outcomes of Patients Diagnosed With Acute Pulmonary Embolism in the Emergency Department: Initial Report of EMPEROR (Multicenter Emergency Medicine Pulmonary Embolism in the Real World Registry)

OBJECTIVES In a large U.S. sample, this study measured the presentation features, testing, treatment strategies, and outcomes of patients diagnosed with pulmonary embolism (PE) in the emergency department (ED). BACKGROUND No data have quantified the demographics, clinical features, management, and outcomes of outpatients diagnosed with PE in the ED in a large, multicenter U.S. study. METHODS Patients of any hemodynamic status were enrolled from the ED after confirmed acute PE or with a high clinical suspicion prompting anticoagulation before imaging for PE. Exclusions were inability to provide informed consent (where required) or unavailability for follow-up. RESULTS A total of 1,880 patients with confirmed acute PE were enrolled from 22 U.S. EDs. Diagnosis of PE was based upon positive results of computerized tomographic pulmonary angiogram in most cases (n = 1,654 [88%]). Patients represented both sexes equally, and racial and ethnic composition paralleled the overall U.S. ED population. Most (79%) patients with PE were employed, and one-third were older than age 65 years. The mortality rate directly attributed to PE was 20 in 1,880 (1%; 95% confidence interval [CI]: 0% to 1.6%). Mortality from hemorrhage was 0.2%, and the all-cause 30-day mortality rate was 5.4% (95% CI: 4.4% to 6.6%). Only 3 of 20 patients with major PE that ultimately proved fatal had systemic anticoagulation initiated before diagnostic confirmation, and another 3 of these 20 received a fibrinolytic agent. CONCLUSIONS Patients diagnosed with acute PE in U.S. EDs have high functional status, and their mortality rate is low. These registry data suggest that appropriate initial medical management of ED patients with severe PE with anticoagulation is poorly standardized and indicate a need for research to determine the appropriate threshold for empiric treatment when PE is suspected before diagnostic confirmation.

The HEART Pathway Randomized Trial Identifying Emergency Department Patients With Acute Chest Pain for Early Discharge

Background—The HEART Pathway is a decision aid designed to identify emergency department patients with acute chest pain for early discharge. No randomized trials have compared the HEART Pathway with usual care. Methods and Results—Adult emergency department patients with symptoms related to acute coronary syndrome without ST-elevation on ECG (n=282) were randomized to the HEART Pathway or usual care. In the HEART Pathway arm, emergency department providers used the HEART score, a validated decision aid, and troponin measures at 0 and 3 hours to identify patients for early discharge. Usual care was based on American College of Cardiology/American Heart Association guidelines. The primary outcome, objective cardiac testing (stress testing or angiography), and secondary outcomes, index length of stay, early discharge, and major adverse cardiac events (death, myocardial infarction, or coronary revascularization), were assessed at 30 days by phone interview and record review. Participants had a mean age of 53 years, 16% had previous myocardial infarction, and 6% (95% confidence interval, 3.6%–9.5%) had major adverse cardiac events within 30 days of randomization. Compared with usual care, use of the HEART Pathway decreased objective cardiac testing at 30 days by 12.1% (68.8% versus 56.7%; P=0.048) and length of stay by 12 hours (9.9 versus 21.9 hours; P=0.013) and increased early discharges by 21.3% (39.7% versus 18.4%; P<0.001). No patients identified for early discharge had major adverse cardiac events within 30 days. Conclusions—The HEART Pathway reduces objective cardiac testing during 30 days, shortens length of stay, and increases early discharges. These important efficiency gains occurred without any patients identified for early discharge suffering MACE at 30 days. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01665521.

Safety and Efficacy of Switching From Either Unfractionated Heparin or Enoxaparin to Bivalirudin in Patients With Non-ST-Segment Elevation Acute Coronary Syndromes Managed With an Invasive Strategy Results From the ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) Trial

OBJECTIVES The aim of this study was to compare outcomes in patients receiving consistent unfractionated heparin (UFH)/enoxaparin (ENOX) therapy and in those switched at randomization to bivalirudin monotherapy. BACKGROUND Crossover between UFH and ENOX has been associated with increased adverse outcomes in patients with acute coronary syndromes. The ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) trial demonstrated superior net clinical outcomes with similar rates of ischemia and significantly less major bleeding with bivalirudin monotherapy compared with UFH/ENOX plus a glycoprotein (GP) IIb/IIIa inhibitor. It is unknown if these results would be preserved in patients switched from UFH/ENOX to bivalirudin monotherapy. METHODS We compared composite ischemia, major bleeding, and net clinical outcomes at 30 days in patients receiving consistent UFH/ENOX therapy and in those switched at randomization from pre-treatment with UFH/ENOX to bivalirudin monotherapy. We also compared outcomes in patients naive to antithrombin therapy who were randomized to UFH/ENOX or bivalirudin monotherapy. RESULTS Two thousand one hundred thirty-seven patients received consistent UFH/ENOX (UFH n = 1,294, ENOX n = 843), and 2,078 patients pre-treated with UFH/ENOX were switched to bivalirudin. Patients switching to bivalirudin had similar rates of ischemia (6.9% vs. 7.4%, p = 0.52), less major bleeding (2.8% vs. 5.8%, p < 0.01), and improved net clinical outcomes (9.2% vs. 11.9%, p < 0.01) than those on consistent UFH/ENOX plus a GP IIb/IIIa inhibitor. Patients naive to antithrombin therapy who were administered bivalirudin (n = 1,427) had similar rates of ischemia (6.2% vs. 5.5%, p = 0.47), less major bleeding (2.5% vs. 4.9%, p < 0.001), and similar net clinical outcomes (8.0% vs. 9.4%, p = 0.17) compared with naive patients administered UFH/ENOX plus a GP IIb/IIIa inhibitor (n = 1,462). CONCLUSIONS Switching from UFH/ENOX to bivalirudin monotherapy results in comparable ischemic outcomes and an approximately 50% reduction in major bleeding compared with consistent UFH/ENOX plus a GP IIb/IIIa inhibitor. Patients naive to antithrombin therapy administered bivalirudin monotherapy had a significant reduction in bleeding and similar rates of ischemia compared with naive patients initiated with UFH or ENOX plus a GP IIb/IIIa inhibitor.

Can the HEART Score Safely Reduce Stress Testing and Cardiac Imaging in Patients at Low Risk for Major Adverse Cardiac Events

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 whether the HEART score could safely reduce objective cardiac testing in patients with low-risk chest pain. METHODS A cohort of chest pain patients was identified from an emergency department-based observation unit registry. HEART scores were determined using registry data elements and blinded chart review. HEART scores were dichotomized into low (0-3) or high risk (>3). The outcome was major adverse cardiac events (MACE); a composite end point of all-cause mortality, myocardial infarction, or coronary revascularization during the index visit or within 30 days. Sensitivity, specificity, and potential reduction of cardiac testing were calculated. RESULTS In a span of 28 months, the registry included 1070 low-risk chest pain patients. MACE occurred in 0.6% (5/904) of patients with low-risk HEART scores compared with 4.2% (7/166) with a high-risk HEART scores (odds ratio = 7.92; 95% confidence interval [95% CI]: 2.48-25.25). A HEART score of >3 was 58% sensitive (95% CI: 32-81%) and 85% specific (95% CI: 83-87%) for MACE. The HEART score missed 5 cases of ACS among 1070 patients (0.5%) and could have reduced cardiac testing by 84.5% (904/1070). Combination of serial troponin >0.065 ng/mL or HEART score >3 resulted in sensitivity of 100% (95% CI: 72-100%), specificity of 83% (95% CI: 81-85%), and potential reduction in cardiac testing of 82% (879/1070). CONCLUSIONS If used to guide stress testing and cardiac imaging, the HEART score could substantially reduce cardiac testing in a population with low pretest probability of ACS.

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

Society of Chest Pain Centers recommendations for the evaluation and management of the observation stay acute heart failure patient-parts 1-6.

588; 95% confidence interval

Identifying Patients for Early Discharge: Performance of Decision Rules Among Patients with Acute Chest Pain

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Safety and efficacy of switching from either unfractionated Heparin or Enoxaparin to Bivalirudin in patients with Non-ST-Segment elevation acute coronary syndromes managed with an invasive strategy. Results from the ACUITY trial

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.

D‐dimer threshold increase with pretest probability unlikely for pulmonary embolism to decrease unnecessary computerized tomographic pulmonary angiography

Making the definitive diagnosis of heart failure in the acute care setting can be difficult. In the emergency department this needs to be done rapidly, frequently, and accurately, without access to a patient’s health records and while simultaneously initiating the appropriate diagnostic and therapeutic interventions. This section reviews the diagnostic strategies available to the physician confronted with a patient in whom the differential diagnosis includes acute heart failure. (Crit Pathways in Cardiol 2008;7: 91–95) Making the Diagnosis of Heart Failure When Patients Present With Symptoms Possibly Related to Acute Heart Failure Making the definitive diagnosis of heart failure (HF) in the acute care setting can be difficult. In the emergency department (ED) this needs to be done rapidly, frequently without access to a patient’s health records while simultaneously initiating the appropriate diagnostic and therapeutic interventions. The physician must determine the etiology of symptoms in patients with suspected HF based on the initial history, physical examination, diagnostic studies (laboratory data, electrocardiogram, and radiography), as well as response to empiric therapy. PubMed was searched in a systematic manner using a combination of search terms relevant to each topic specific to early diagnosis available in the emergency department setting. References from articles and guidelines so identified were also evaluated for additional pertinent literature. The Initial History and Physical Examination The most common symptom of HF is dyspnea. However, dyspnea is also common in the general population. Even in well persons, a lack of physical fitness may result in exertional dyspnea. Multiple other medical conditions also produce dyspnea, including chronic obstructive pulmonary disease (COPD), asthma, pneumonia, and myocardial ischemia (Table 1). In several studies and registries of presumed HF, up to 40% of patients had a history of COPD. Therefore, in the acute care setting, a chief complaint of dyspnea is very nonspecific. Other components of a complete history include assessment of abdominal distention, paroxysmal nocturnal dyspnea, orthopnea, fatigue, weakness, nausea, and vomiting. The presence of paroxysmal nocturnal dyspnea, orthopnea, or dyspnea on exertion increases the likelihood of HF, whereas their absence decreases its likelihood. One of the more reliable indicators that dyspnea is due to an acute exacerbation of HF is a previous history of HF. However, approximately 20% of patients admitted with acute heart failure have a history of COPD. A history is most beneficial when combined with other information but by itself will make the accurate diagnosis of HF challenging. Auscultation for an S3 gallop, assessment for jugular venous distension (JVD), auscultation for pulmonary rales, and assessment for leg edema should be part of the initial evaluation of a patient with suspected HF, and the presence of these signs increases the likelihood of HF. The absence of rales, edema, or JVD lowers the probability of HF. An S3 is difficult to detect in the emergency department. Electronic identification of an S3 should improve detection and diagnosis of HF, although studies have yet to show an effect on patient outcome.