J. Douglas Kirk

Immediate exercise testing to evaluate low-risk patients presenting to the emergency department with chest pain

OBJECTIVES Our purpose was to determine the safety and accuracy of immediate exercise testing in low-risk patients presenting to the emergency department (ED) with chest pain suggestive of a cardiac etiology. BACKGROUND Safe, efficient management of low-risk patients presenting to the ED with chest pain is a continuing challenge. We have employed immediate exercise testing to evaluate a large, heterogeneous group of low-risk patients presenting with chest pain. METHODS Patients presenting to the ED with chest pain compatible with a cardiac origin and clinical evidence of low risk on initial assessment underwent immediate exercise treadmill testing in our chest pain evaluation unit. Indicators of low clinical risk included no evidence of hemodynamic instability, arrhythmias or electrocardiographic signs of ischemia. Serial measurements of cardiac injury markers were not obtained. RESULTS Exercise testing was performed to a sign- or symptom-limited end point in 1,000 patients (520 men, 480 women; age range 31 to 82 years) and was positive for ischemia in 13%, negative in 64% and nondiagnostic in 23% of patients. There were no adverse effects of exercise testing, and all patients with a negative exercise test were discharged directly from the ED. At 30-day follow-up there was no mortality in any of the three groups. Cardiac events in the three groups included: negative group, 1 non-Q-wave myocardial infarction (MI); positive group, 4 non-Q-wave MIs and 12 myocardial revascularizations; nondiagnostic group, 7 myocardial revascularizations. BACKGROUND Immediate exercise testing of patients presenting to the ED with chest pain and evidence of low clinical risk is safe and accurate for determining those who require admission and those who can be discharged to further outpatient evaluation.

Immediate exercise testing of low risk patients with known coronary artery disease presenting to the emergency department with chest pain

OBJECTIVES The purpose of this study was to demonstrate the safety and utility of immediate exercise treadmill testing (IETT) of low risk patients presenting to the emergency department with known coronary artery disease (CAD). BACKGROUND More than 70% of the two million patients admitted to U.S. hospitals annually for suspected acute myocardial infarction (AMI) are found not to have had a cardiac event. We have previously demonstrated the safety and efficacy of IETT of selected low risk patients without known CAD presenting to the emergency department with chest pain. This study extends this approach to selected patients with a history of CAD. METHODS One hundred patients evaluated by the chest pain emergency room to rule out AMI underwent IETT using a modified Bruce protocol upon admission to the hospital (median time <1 h). RESULTS Twenty-three patients (23%) had positive exercise electrocardiograms (ExECGs); an uncomplicated non-Q wave AMI was diagnosed in two patients. Thirty-eight patients (38%) had negative ExECGs and 39 patients (39%) had nondiagnostic ExECGs. Of these 100 patients, 64 were discharged immediately after IETT, 19 were discharged in less than 24 h after negative serial cardiac enzymes and stable electrocardiograms and 17 were discharged after further evaluation and treatment. There were no complications from exercise testing and no late deaths or AMI during six-month follow-up. CONCLUSIONS Immediate exercise treadmill testing of low risk patients with chest pain and known CAD is effective in further stratifying this group into patients who can be safely discharged and those who require hospital admission.

Emergency Department and Office-Based Evaluation of Patients With Chest Pain

The management of patients with chest pain is a common and challenging clinical problem. Although most of these patients do not have a life-threatening condition, the clinician must distinguish between those who require urgent management of a serious problem such as acute coronary syndrome (ACS) and those with more benign entities who do not require admission. Although clinical judgment continues to be paramount in meeting this challenge, new diagnostic modalities have been developed to assist in risk stratification. These include markers of cardiac injury, risk scores, early stress testing, and noninvasive imaging of the heart. The basic clinical tools of history, physical examination, and electrocardiography are currently widely acknowledged to allow early identification of low-risk patients who have less than 5% probability of ACS. These patients are usually initially managed in the emergency department and transitioned to further outpatient evaluation or chest pain units. Multiple imaging strategies have been investigated to accelerate diagnosis and to provide further risk stratification of patients with no initial evidence of ACS. These include rest myocardial perfusion imaging, rest echocardiography, computed tomographic coronary angiography, and cardiac magnetic resonance imaging. All have very high negative predictive values for excluding ACS and have been successful in reducing unnecessary admissions for patients at low to intermediate risk of ACS. As patients with acute chest pain transition from the evaluation in the emergency department to other outpatient settings, it is important that all clinicians involved in the care of these patients understand the tools used for assessment and risk stratification.

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

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.

The Impact of Race on the Acute Management of Chest Pain

OBJECTIVES African Americans with acute coronary syndromes receive cardiac catheterization less frequently than whites. The objective was to determine if such disparities extend to acute evaluation and non interventional treatment. METHODS Data on adults with chest pain (N = 7,935) presenting to eight emergency departments (EDs) were evaluated from the Internet Tracking Registry of Acute Coronary Syndromes. Groups were selected from final ED diagnosis: 1) acute myocardial infarction (AMI), n = 400; 2) unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI), n = 1,153; and 3) nonacute coronary syndrome chest pain (non-ACS CP), n = 6,382. American College of Cardiology/American Heart Association guidelines for AMI and UA/NSTEMI were used to evaluate racial disparities with logistic regression models. Odds ratios (ORs) were adjusted for age, gender, guideline publication, and insurance status. Non-ACS CP patients were assessed by comparing electrocardiographic (ECG)/laboratory evaluation, medical treatment, admission rates, and invasive and noninvasive testing for coronary artery disease (CAD). RESULTS African Americans with UA/NSTEMI received glycoprotein IIb/IIIa receptor inhibitors less often than whites (OR, 0.41; 95% CI = 0.19 to 0.91). African Americans with non-ACS CP underwent ECG/laboratory evaluation, medical treatment, and invasive and noninvasive testing for CAD less often than whites (p < 0.05). Other nonwhites with non-ACS CP were admitted and received invasive testing for CAD less often than whites (p < 0.01). African Americans and other nonwhites with AMI underwent catheterization less frequently than whites (OR, 0.45; 95% CI = 0.29 to 0.71 and OR, 0.40; 95% CI = 0.17 to 0.92, respectively). A similar disparity in catheterization was noted in UA/NSTEMI therapy (OR, 0.53; 95% CI = 0.40 to 0.68 and OR, 0.68; 95% CI = 0.47 to 0.99). CONCLUSIONS Racial disparities in acute chest pain management extend beyond cardiac catheterization. Poor compliance with recommended treatments for ACS may be an explanation.

International variations in the clinical, diagnostic, and treatment characteristics of emergency department patients with acute heart failure syndromes

Results from investigations in one area of the world may not translate to another if patient characteristics and practices differ. We examine differences in the presentation and management of emergency department (ED) patients with dyspnoea from acute heart failure syndromes (AHFS) between the USA, Western Europe, and Eastern Europe.

Illicit Stimulant Use in a United States Heart Failure Population Presenting to the Emergency Department (from the Acute Decompensated Heart Failure National Registry Emergency Module)

Illicit stimulant drug use may have a profound clinical impact in acute decompensated heart failure (ADHF). The chronic use of cocaine and methamphetamine may lead to overt cardiomyopathy and ADHF. The Acute Decompensated Heart Failure National Registry Emergency Module (ADHERE-EM) collected data on patients presenting to emergency departments with ADHF at 83 geographically dispersed hospitals in the United States. This registry was queried to determine the rate of self-reported illicit drug use in emergency department patients presenting with ADHF and compare these patients with those without illicit drug use. The registry enrolled 11,258 patients with ADHF with drug use data from January 2004 to March 2006. Of these patients, 594 (5.3%) self-reported current or past stimulant drug use. Compared with nonusers, these patients were more likely to be younger (median age 49.7 vs 76.1 years), to be African American (odds ratio 11.9, 95% confidence interval 9.8 to 14.4), and to have left ventricular ejection fractions <40% (odds ratio 3.4, 95% confidence interval 2.8 to 4.2). Admitted users had no difference in mortality (adjusted odds ratio 0.83, 95% confidence interval 0.25 to 2.72) compared with nonusers. In conclusion, data from ADHERE-EM suggest that a clinically important percentage of patients with ADHF report the use of illicit stimulant drugs. Although these patients are younger with a greater degree of LV dysfunction, they did not have greater risk-adjusted mortality.

Acute ischemic syndromes: Chest pain center concept

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

Risk stratification in women enrolled in the Acute Decompensated Heart Failure National Registry Emergency Module (ADHERE-EM)

OBJECTIVES It has been reported that the mortality risk for heart failure differs between men and women. It has been postulated that this is due to differences in comorbid features. Variation in risk profiles by gender may limit the performance of stratification algorithms available for heart failure in women. This analysis examined the ability of a published risk stratification model to predict outcomes in women. METHODS The Acute Decompensated Heart Failure National Registry Emergency Module (ADHERE-EM) database was used. Characteristics, treatments, and outcomes for men and women were compared. The ADHERE registry classification and regression tree (CART) analysis was used for the risk stratification evaluation. RESULTS Of 10,984 ADHERE-EM patients, 5,736 (52.2%) were women. In-hospital mortality was similar between men and women (p = 0.727). Significant differences (p < 0.0002) were noted by gender in all three variables in the CART model (blood urea nitrogen [BUN] > or = 43 mg/dL, systolic blood pressure < 115 mm Hg, and serum creatinine > or = 2.75 mg/dL). However, the CART model effectively stratified both genders into distinct risk groups with no significant difference in mortality by gender within stratified groups. CONCLUSIONS The ADHERE Registry CART tool is effective at predicting risk in ED patients, regardless of gender.

Emergency Physician High Pretest Probability for Acute Coronary Syndrome Correlates with Adverse Cardiovascular Outcomes

OBJECTIVES The value of unstructured physician estimate of risk for disease processes, other than acute coronary syndrome (ACS), has been demonstrated. The authors sought to evaluate the predictive value of unstructured physician estimate of risk for ACS in emergency department (ED) patients without obvious initial evidence of a cardiac event. METHODS This was a post hoc secondary analysis of the Internet Tracking Registry for Acute Coronary Syndromes (i*trACS), a prospectively collected multicenter data registry of patients over the age of 18 years presenting to the ED with symptoms of ACS between 1999 and 2001. In this registry, following patient history, physical exam, and electrocardiogram (ECG), the unstructured treating physician estimate of risk was recorded. A 30-day follow-up and a medical record review were used to determine rates of adverse cardiac events, death, myocardial infarction (MI), or revascularization procedure. The analysis included all patients with nondiagnostic ECG changes, normal initial biomarkers, and a non-MI initial impression from the registry and excluded those without complete data or who were lost to follow-up. Data were stratified by unstructured physician risk estimate: noncardiac, low risk, high risk, or unstable angina. RESULTS Of 15,608 unique patients in the registry, 10,145 met inclusion/exclusion criteria. Patients were defined as having unstable angina in 6.0% of cases; high risk, 23.5% of cases; low risk, 44.2%; and noncardiac, 26.3% of cases. Adverse cardiac event rates had an inverse relationship, decreasing from 22.0% (95% confidence interval [CI] = 18.8% to 25.6%) for unstable angina, 10.2% (95% CI = 9.0% to 11.5%) for those stratified as high risk, 2.2% (95% CI = 1.8% to 2.6%) for low risk, and to 1.8% (95% CI = 1.4% to 2.4%) for noncardiac. The relative risk (RR) of an adverse cardiac event for those with an initial label of unstable angina compared to those with a low-risk designation was 10.2 (95% CI = 8.0 to 13.0). The RR of an event for those with a high-risk initial impression compared to those with a low-risk initial impression was 4.7 (95% CI = 3.8 to 5.9). The risk of an event among those with a low-risk initial impression was the same as for those with a noncardiac initial impression (RR = 0.83, 95% CI = 0.6 to 1.2). CONCLUSIONS In ED patients without obvious initial evidence of a cardiac event, unstructured emergency physician (EP) estimate of risk correlates with adverse cardiac outcomes.