Stress echo in chest pain unit: the SPEED trial

[Stress-Echocardiography in Low-risk Acute Coronary Syndrome Without Persistent ST-segment Elevation Diagnostic Algorithm]

This review addresses the capabilities of stress EchoCG as a simple, non-invasive, non-radiation method for diagnosing occult disorders of coronary blood flow in patients with non-ST-elevation acute coronary syndrome on a low-risk electrocardiogram. The capabilities of the enhanced stress EchoCG protocol are based on supplementing the standard detection of transient disturbances of local contractility, generally associated with coronary artery obstruction, with an assessment of the heart rate reserve, coronary reserve and other parameters. This approach is considered promising for a more complete characterization of heart function during exercise and an accurate prognosis of the clinical case, which allows determining the tactics for patient management not limited to selection for myocardial revascularization.

Reduced coronary flow velocity reserve and blunted heart rate reserve identify a higher risk group in patients with chest pain and negative emergency department evaluation

To estimate the prognostic value of stress echo (SE) with the assessment of coronary flow velocity reserve (CFVR) and heart rate reserve (HRR) in patients admitted for chest pain with non-diagnostic EKG, negative troponin, and without inducible regional wall motion abnormalities (RWMA). 658 patients (age 67 ± 12 years) admitted to our Emergency Department with chest pain, non-diagnostic EKG, and negative serial troponin underwent dipyridamole (0.84 mg/kg in 6') SE with simultaneous assessment of RWMA, CFVR in the left anterior descending artery, and HRR as peak/rest heart rate. The outcome measure was all-cause mortality. Of the 658 patients initially enrolled, 20 (3%) showed RWMA during SE and were referred to ischemia-driven revascularization. In the remaining 638, CFVR was abnormal (≤ 2.0) in 148 patients (23%). HRR was abnormal (≤ 1.22 in patients in sinus rhythm, or ≤ 1.17 in patients with permanent atrial fibrillation) in 196 patients (31%). During a follow-up of 7.3 ± 4.3 years, 151 (24%) patients died. Survival at 8 years was 93% in patients with normal CFVR and HRR, 76% in patients with abnormal CFVR only, 73% in patients with abnormal HRR only, and 38% in those with abnormal CFVR and HRR (p < 0.0001). At multivariable analysis, abnormal CFVR (HR 1.49, 95% CI 1.05-2.10, p = 0.02) and abnormal HRR (HR 2.01, 95% CI 1.43-2.84, p < 0.0001) were independent predictors of survival. In admitted patients with non-ischemic EKG, negative serial troponin, and without RWMA during dipyridamole SE, a reduced CFVR and blunted HRR independently identify a subset with worse survival in the long term. Upper panel: Color and pulsed-wave Doppler with the electrocardiographic lead tracing of Four different response patterns (from left to right): normal CFVR and HRR; normal CFVR, abnormal HRR; abnormal CFVR, normal HRR; abnormal CFVR and HRR. Lower panel: The annualized death rate for each of the four groups with negative SE for RWMA and stratified according to the presence of CFVR and HRR: none, one, or two abnormalities.

Major adverse cardiac events after emergency department evaluation of chest pain patients with advanced testing: Systematic review and meta-analysis

OBJECTIVES

Our primary objective was to describe the risk of major adverse cardiac events (MACE) at 1, 6, and 12 months after a negative coronary computed tomography angiogram (cCTA), electrocardiogram (ECG) stress test, stress echocardiography, and myocardial perfusion scintigraphy (MPS) in low- to intermediate-risk patients.

METHODS

Initially, 952 articles were identified for screening, 81 met criteria for full-text review, and once risk of bias was assessed, 33 articles were included in this meta-analysis. We utilized a random-effects model to assess pooled MACE event proportion for patients undergoing evaluation of acute coronary syndrome (ACS) when risk stratified to a low- to intermediate-risk category after undergoing standard testing. Heterogeneity analysis was performed using Cochrane's Q-test and I² statistic.

RESULTS

Twenty-one studies evaluated follow-up at 1 month with cCTA having a 0.09% (95% confidence interval [CI] = 0.03% to 0.26%) pooled MACE compared to 0.23% (95% CI = 0.01% to 5.8%) of the exercise stress testing (p = 1). MPS and cCTA had an overall event rate of 0.15% (95% CI = 0.06% to 0.41%) at 6 months (I²  = 0%). At 12 months, a subgroup analysis found a pooled cCTA MACE of 0.16% (95% CI = 0.04% to 0.65%) compared to 1.68% (95% CI = 0.01% to 2.6%) for stress echocardiography with low within-group heterogeneity (I²  = 0%). Subgroup analysis of cCTA with no disease versus nonobstructive disease (<50% stenosis) did not find statistical difference in the MACE at both 1 month (0.17% [95% CI = 0.04% to 0.67%] vs. 0.06% [95% CI = 0.01% to 0.34%]) and 12 months (0.44% [95% CI = 0.09% to 2.2% vs. 0.54% [95% CI = 0.19% to 1.5%]).

CONCLUSIONS

Patients presenting with chest pain who have a coronary CTA showing < 50% stenosis, negative ECG stress test, stress echocardiography, or stress myocardial perfusion scan in the past 12 months can be discharged without any further risk stratification if their ECG and troponin are reassuring given low MACE.

Coronary artery calcium score: pivotal role as a predictor for detecting coronary artery disease in symptomatic patients

Chest pain and dyspnea are common presentations for symptomatic individuals with suspected coronary artery disease (CAD) in the primary care office and cardiology clinics. However, it is imperative to properly diagnose who should undergo further evaluation for cardiac etiologies of chest pain, with either noninvasive or invasive imaging tests. The purpose of this review is to highlight the role of coronary artery calcium (CAC) score as a screening tool for symptomatic patients to detect CAD. The purpose of CAC scoring is to establish the presence and severity of coronary atherosclerosis that can play a vital role in symptomatic patients. The use of CAC testing in symptomatic patients has traditionally been limited due to fundamental concerns, including the occurrence of coronary calcification relatively late in the atherosclerotic process and high prevalence of CAC in the population. Further issue relates to its low specificity for obstructive CAD, as well as demonstration of significant ethnic variability in plaque composition and calcification patterns. CAC testing gained attention as an inexpensive, rapid, reproducible and a well-tolerated alternative to exclude CAD in symptomatic patients and defer further invasive imaging tests. This article will review the available literature in regard to the use of CAC in symptomatic populations.

Real-world performance and accuracy of stress echocardiography: the EVAREST observational multi-centre study

Aims

Stress echocardiography is widely used to identify obstructive coronary artery disease (CAD). High accuracy is reported in expert hands but is dependent on operator training and image quality. The EVAREST study provides UK-wide data to evaluate real-world performance and accuracy of stress echocardiography.

Methods and results

Participants undergoing stress echocardiography for CAD were recruited from 31 hospitals. Participants were followed up through health records which underwent expert adjudication. Cardiac outcome was defined as anatomically or functionally significant stenosis on angiography, revascularization, medical management of ischaemia, acute coronary syndrome, or cardiac-related death within 6 months. A total of 5131 patients (55% male) participated with a median age of 65 years (interquartile range 57–74). 72.9% of studies used dobutamine and 68.5% were contrast studies. Inducible ischaemia was present in 19.3% of scans. Sensitivity and specificity for prediction of a cardiac outcome were 95.4% and 96.0%, respectively, with an accuracy of 95.9%. Sub-group analysis revealed high levels of predictive accuracy across a wide range of patient and protocol sub-groups, with the presence of a resting regional wall motion abnormalitiy significantly reducing the performance of both dobutamine (P < 0.01) and exercise (P < 0.05) stress echocardiography. Overall accuracy remained consistently high across all participating hospitals.

Conclusion

Stress echocardiography has high accuracy across UK-based hospitals and thus indicates stress echocardiography is being delivered effectively in real-world practice, reinforcing its role as a first-line investigation in the assessment of patients with stable chest pain.

Echocardiography in the Era of Obesity

Patients with obesity are at increased risk for coronary artery disease and heart failure and often present with symptoms of dyspnea, fatigue, edema, or chest pain. Echocardiography is frequently used to help distinguish whether these symptoms are due to cardiac disease. Unfortunately, obesity has a significant impact on image quality because of signal attenuation. Ultrasound-enhancing agents may improve the detection of structural remodeling and subclinical left ventricular dysfunction in patients with obesity. Assessment of chamber sizes and cardiac remodeling in severely obese subjects must be interpreted with caution, however, as the current recommendations for indexing cardiac chamber sizes to body size may lead to false conclusions about chamber volumes or mass, particularly in settings in which weight is changing. As a result of increases in stroke volume and cardiac output, obesity may exacerbate hemodynamic compromise in obstructive structural or valvular disease. With regard to assessment of ischemic heart disease, stress echocardiography can effectively risk-stratify patients with obesity and may have advantages over other noninvasive modalities. In general, transesophageal echocardiography is safe in patients with obesity, although some precautions should be observed. Stress echocardiography using the transesophageal approach is an alternative for preoperative or ischemia evaluation in patients with suboptimal transthoracic views.

The value of negative stress echocardiography in predicting cardiovascular events among adults with no known coronary disease

Introduction: Stress echocardiography is a safe and cost-effective method of evaluating the patients with suspected coronary artery disease (CAD). However, the risk factors of an adverse cardiovascular event after a normal exercise (ESE) or dobutamine (DSE) stress echocardiography are not well established.

Methods: A cohort of 705 patients without previous history of CAD and a negative ESE/DSE was studied. All studies were performed in a high-volume echocardiologic laboratory and interpreted by two experienced echocardiography-trained cardiologists. Patients with inconclusive studies and those with an evidence of myocardial ischemia were excluded. Demographic, echocardiographic and hemodynamic findings were recorded. Patients were followed for at least 2 years. Independent predictors of major adverse cardiovascular events (MACE) were determined by regression analysis.

Results: During a period of 55.7±17.5 months, MACE occurred in 35 (5.0%) of patients. Negative predictive value (NPV) of DSE was 89.2%, which was significantly less than 96.5% for ESE in predicting the occurrence of MACE (P = 0.001). MACE occurred more frequently among older (≥65 years) men with preexisting diabetes, hypertension, and/or hyperlipidemia. During ESE, a higher maximum blood pressure*heart rate product for the achieved level of metabolic equivalent (METS) of tasks was also an independent predictor of MACE.

Conclusion: Inability of patients to undergo traditional ESE that led to the choice of using DSE alternative reduces the NPV of the stress echocardiography among patients without previous history of CAD. A modest rise of heart rate and blood pressure in response to increased level of activity serves as favorable prognostic value and improves the NPV of stress echocardiography.

HEART Score and Stress Test Emergency Department Bayesian Decision Scheme: Results from the Acute Care Diagnostic Collaboration

BACKGROUND

Accurate identification of patients at risk of major adverse cardiac events (MACE) places a substantial burden on emergency physicians (EPs). Bayesian nomogram for risk stratification in low- to intermediate-risk cardiovascular patients has not been investigated previously.

OBJECTIVE

The objective of this study was to develop a comparative diagnostic model using Bayesian statistics for exercise treadmill test (ETT) and stress echocardiogram (ECHO) to calculate post-test diagnostic risk of MACE using HEART (history, electrocardiogram, age, risk factors, and troponin) risk score as predictor of pretest probability.

METHODS

Stratification was made by applying HEART scores for the prediction of MACE. Likelihood ratios (LR) were calculated using pooled sensitivity and specificity of ETT and ECHO from the American College of Cardiology Foundation/American Heart Association systematic review. Post-test probabilities were obtained after inserting HEART score and LR into Bayesian nomogram. Analysis of variance was used to assess statistical association.

RESULTS

Positive LR (LR+) for ETT was 4.56 and negative LR (LR-) was 0.27; for ECHO, LR+ 5.65 and LR- 0.15. Bayesian statistical modeling post-test probabilities for LR+ and low HEART risk yielded a post-test probability for ETT of 7.75% and 9.09% for ECHO; intermediate risk gave 47.62% and 52.63%, respectively. For LR-, low HEART risk post-test probability for ETT was 0.46% and for ECHO 0.26%; intermediate risk probabilities were 4.48% and 2.49%, respectively. LR- was statistically significant in ruling out MACE with ECHO (p < 0.001), but no significant differences were seen for LR+ (p = 0.64).

CONCLUSIONS

This Bayesian analysis demonstrated slight superiority of stress ECHO over ETT in low- and intermediate-risk patients in ruling out MACE.

Diagnostic Evaluation of Nontraumatic Chest Pain in Athletes

This article is a clinically relevant review of the existing medical literature relating to the assessment and diagnostic evaluation for athletes complaining of nontraumatic chest pain. The literature was searched using the following databases for the years 1975 forward: Cochrane Database of Systematic Reviews; CINAHL; PubMed (MEDLINE); and SportDiscus. The general search used the keywords chest pain and athletes. The search was revised to include subject headings and subheadings, including chest pain and prevalence and athletes. Cross-referencing published articles from the databases searched discovered additional articles. No dissertations, theses, or meeting proceedings were reviewed. The authors discuss the scope of this complex problem and the diagnostic dilemma chest pain in athletes can provide. Next, the authors delve into the vast differential and attempt to simplify this process for the sports medicine physician by dividing potential etiologies into cardiac and noncardiac conditions. Life-threatening causes of chest pain in athletes may be cardiac or noncardiac in origin, which highlights the need for the sports medicine physician to consider pathology in multiple organ systems simultaneously. This article emphasizes the importance of ruling out immediately life threatening diagnoses, while acknowledging the most common causes of noncardiac chest pain in young athletes are benign. The authors propose a practical algorithm the sports medicine physician can use as a guide for the assessment and diagnostic work-up of the athlete with chest pain designed to help the physician arrive at the correct diagnosis in a clinically efficient and cost-effective manner.

Chest pain: coronary CT in the ER

Cardiac CT has developed into a robust clinical tool during the past 15 years. Of the fields in which the potential of cardiac CT has raised more interest is chest pain in acute settings. In fact, the possibility to exclude with high reliability obstructive coronary artery disease (CAD) in patients at low-to-intermediate risk is of great interest both from the clinical standpoint and from the management standpoint. Several other modalities, with or without imaging, have been used during the past decades in the settings of new onset chest pain or in acute chest pain for both diagnostic and prognostic assessment of CAD. Each one has advantages and disadvantages. Most imaging modalities also focus on inducible ischaemia to guide referral to invasive coronary angiography. The advent of cardiac CT has introduced a new practice diagnostic paradigm, being the most accurate non-invasive method for identification and exclusion of CAD. Furthermore, the detection of subclinical CAD and plaque imaging offer the opportunity to improve risk stratification. Moreover, recent advances of the latest generation CT scanners allow combining both anatomical and functional imaging by stress myocardial perfusion. The role of cardiac CT in acute settings is already important and will become progressively more important in the coming years.

Incremental value of exercise echocardiography over exercise electrocardiography in a chest pain unit

BACKGROUND

Limited data are available on the added value of exercise echocardiography (ExEcho) over exercise electrocardiography (ExECG) in patients with suspected acute coronary syndromes (ACS) referred to a chest pain unit. We aimed to assess the incremental value of ExEcho over ExECG in this setting.

METHODS

ExECG and ExEcho were performed in parallel in 1052 patients with suspected ACS, nondiagnostic but interpretable electrocardiograms, and negative serial troponin results. The primary outcome was a composite of coronary death, nonfatal myocardial infarction or unstable angina with angiographic documentation of significant coronary artery disease within 6 months.

RESULTS

The primary outcome occurred in 2/614 patients (0.3%) with both negative ExECG and ExEcho, 3/60 (5%) with positive ExECG and negative ExEcho, 73/135 (54.1%) with negative ExECG and positive ExEcho, 106/136 (77.9%) with both positive ExECG and ExEcho, and 8/107 (7.5%) with inconclusive results. The addition of ExEcho data to a model based on clinical and ExECG data significantly increased the c statistic from 0.898 to 0.968 (change +0.070, 95% confidence interval 0.052-0.092), with a continuous net reclassification improvement of 1.56 and an integrated discrimination improvement of 22% (p<0.001). Decision curve analysis showed that a strategy of referral to coronary angiography based on ExEcho was associated with the highest net benefit and with the largest reduction in unnecessary coronary angiographies.

CONCLUSION

ExEcho provides significant incremental prognostic information and higher net clinical benefit than a strategy based on ExECG in patients referred to a chest pain unit for suspected ACS and negative troponin levels.

Myocardial deformation by strain echocardiography identifies patients with acute coronary syndrome and non-diagnostic ECG presenting in a chest pain unit: a prospective study of diagnostic accuracy

OBJECTIVE

Clinical assessment often cannot risk stratify patients hospitalized with chest pain and non-diagnostic electrocardiography (ECG) or myocardial enzymes. An inappropriate admission of patients with non-cardiac chest pain is an enormous cost factor.

METHODS

2315 patients who presented in the chest pain unit (CPU) with symptoms suggestive of acute coronary syndrome (ACS) were screened. All patients with relevant changes in ECG or myocardial enzymes were excluded. 268 consecutive patients (mean 58 ± 7 years, 88 men) were prospectively included and underwent echocardiography for left ventricular ejection fraction (LVEF), wall motion score index (WMSI) and strain parameter and a coronary angiography (CA) within 2 ± 1 days after admission.

RESULTS

Anatomically obstructive coronary artery disease (CAD) (≥70 % diameter stenosis) was present in 110 patients (41 %). The incremental value of LVEF, WMSI, and strain parameters to relevant clinical variables was determined in nested Cox models. Baseline clinical data associated with relevant CAD were age [hazard ratio (HR) 1.31, p = 0.03], arterial hypertension (HR 1.39, p = 0.03) and diabetes (HR 1.46, p = 0.001). The addition of endocardial global circumferential strain (GCS) (HR 1.57, p < 0.001) caused the greatest increment in model power (χ (2) = 43.4, p < 0.001). Optimal cut-off value was calculated as -21.7 % for GCS (sensitivity 87 %, specificity 76 %) to differentiate between these patients.

CONCLUSIONS

In patients with suspected ACS but without ECG changes or myocardial enzyme abnormalities, myocardial deformation imaging can identify patients at risk. This approach may be applied to improve decision guidance at the CPU for fast discharge of patients with non-cardiac chest pain or prompt cardiological allocation of patients with CAD.

CLINICAL TRIAL REGISTRATION

NCT 02357641.

Finding the Gatekeeper to the Cardiac Catheterization Laboratory: Coronary CT Angiography or Stress Testing?

Functional capacity is a robust predictor of clinical outcomes, and stress testing is used in current practice paradigms to guide referral to invasive coronary angiography. However, invasive coronary angiography is driven by ongoing symptoms, as well as risk of adverse outcomes. The limitations of current functional testing-based paradigms might be avoided by using coronary computed tomographic angiography (CCTA) for exclusion of obstructive coronary artery disease. The growth of CCTA has been supported by comparative prognostic evidence with CCTA and functional testing, as well as radiation dose reduction. Use of CCTA for physiological evaluation of coronary lesion-specific ischemia may facilitate evaluation of moderate stenoses, designation of the culprit lesion, and prediction of benefit from revascularization. The potential of CCTA to serve as an effective gatekeeper to invasive coronary angiography will depend, in part, on the adoption of these new developments, as well as definition of the benefit of detecting high-risk plaque for guiding the management of selected patients.

Prognostic value of normal stress echocardiography in obese patients

BACKGROUND

Chest pain is a common problem in obese patients. Because of the body habitus, the results of noninvasive evaluation for CAD may be limited in this group.

METHODS

We reviewed the records of 1446 consecutive patients who had undergone clinically indicated stress echocardiography (SE). We compared major adverse cardiac events (MACE; myocardial infarction, cardiac intervention, cardiac death, subsequent hospitalization for cardiac events, and emergency department visits) at 1 year in normal weight, overweight, and obese subjects with normal SE.

RESULTS

Excluding patients with an abnormal and indeterminate SE and those who were lost to follow-up, a retrospective analysis of 704 patients was performed. There were 366 obese patients (BMI ≥ 30), 196 overweight patients (BMI 25-29.9), and 142 patients with normal BMI (18.5-24.9). There was no MACE in the groups at 1-year follow-up after a normal SE.

CONCLUSIONS

In obese patients including those with multiple risk factors and symptoms concerning for cardiac ischemia, stress echocardiography is an effective and reliable noninvasive tool for identifying those with a low 1-year risk of cardiac events.

Rationale and design of a randomized trial comparing initial stress echocardiography versus coronary CT angiography in low-to-intermediate risk emergency department patients with chest pain

BACKGROUND

Comparative effectiveness research (CER) has become a major focus of cardiovascular disease investigation to optimize diagnosis and treatment paradigms and decrease healthcare expenditures. Acute chest pain is a highly prevalent reason for evaluation in the Emergency Department (ED) that results in hospital admission for many patients and excess expense. Improvement in noninvasive diagnostic algorithms can potentially reduce unnecessary admissions.

OBJECTIVE

To compare the performance of treadmill stress echocardiography (SE) and coronary computed tomography angiography (CTA) in ED chest pain patients with low-to-intermediate risk of significant coronary artery disease.

DESIGN

This is a single-center, randomized controlled trial (RCT) comparing SE and CTA head-to-head as the initial noninvasive imaging modality. The primary outcome measured is the incidence of hospitalization. The study is powered to detect a reduction in admissions from 28% to 15% with a sample size of 400. Secondary outcomes include length of stay in the ED/hospital and estimated cost of care. Safety outcomes include subsequent visits to the ED and hospitalizations, as well as major adverse cardiovascular events at 30 days and 1 year. Patients who do not meet study criteria or do not consent for randomization are offered entry into an observational registry.

CONCLUSIONS

This RCT will add to our understanding of the roles of different imaging modalities in triaging patients with suspected angina. It will increase the CER evidence base comparing SE and CTA and provide insight into potential benefits and limitations of appropriate use of treadmill SE in the ED.

Stress echocardiography in the ED: diagnostic performance in high-risk subgroups

PURPOSE

To assess stress-echo (SE) diagnostic performance in patients presenting to the emergency department (ED) with spontaneous chest pain, especially in subgroups in which exercise ECG diagnostic performance has been questioned (women, elderly, history of coronary artery disease).

METHODS

Between June 2008 and May 2011, 474 patients with an episode of spontaneous chest pain, non-diagnostic electrocardiogram and negative cardiac necrosis markers underwent SE. Patients with inducible ischemia (Isch) were asked to undergo coronary angiography. Patients with negative SE were discharged and contacted by telephone at least 6 months after discharge, to ascertain the occurrence of new cardiac events.

MAIN FINDINGS

Exercise stress-echo (ESE) was employed in 270 patients and dobutamine (DSE) in 218 (including 14 with inconclusive ESE); a diagnosis of coronary artery disease (CAD) was confirmed or excluded in 434 (92%) patients. SE was negative for Isch in 318 patients (206 ESE and 112 DSE) and positive in 132. During follow-up, patients with negative SE had 4 cardiac events. SE showed: sensitivity 90%, specificity 92%, positive predictive value 78% and negative predictive value 97%. Sensitivity was comparable between patients aged < or ≥70 years (84 vs 94%) and between gender (89 vs 96%), but lower in patients with known CAD (88 vs 94%, P < .05); specificity was comparable regardless of age (94 vs 99%) and presence of CAD (97 vs 91%), but was lower among women (87 vs 96%, P < .05).

CONCLUSIONS

SE had a very good diagnostic performance in ED patients with suspected Isch, both overall and in selected high-risk groups.

Imaging strategies for acute chest pain in the emergency department

OBJECTIVE

Echocardiography, radionuclide myocardial perfusion imaging (MPI), and coronary CT angiography (CTA) are the three main imaging techniques used in the emergency department for the diagnosis of acute coronary syndrome (ACS). The purpose of this article is to quantitatively examine existing evidence about the diagnostic performance of these imaging tests in this setting.

CONCLUSION

Our systematic search of the medical literature showed no significant difference between the modalities for the detection of ACS in the emergency department. There was a slight, positive trend favoring coronary CTA. Given the absence of large differences in diagnostic performance, practical aspects such as local practice, expertise, medical facilities, and individual patient characteristics may be more important.

Coronary CT and the coronary calcium score, the future of ED risk stratification?

Accurate and efficient evaluation of acute chest pain remains clinically challenging because traditional diagnostic modalities have many limitations. Recent improvement in non-invasive imaging technologies could potentially improve both diagnostic efficiency and clinical outcomes of patients with acute chest pain while reducing unnecessary hospitalizations. However, there is still controversy regarding much of the evidence for these technologies. This article reviews the role of coronary artery calcium score and the coronary computed tomography in the assessment of individual coronary risk and their usefulness in the emergency department in facilitating appropriate disposition decisions. The evidence base and clinical applications for both techniques are also described, together with cost- effectiveness and radiation exposure considerations.

Cardiac CT in the emergency department

Current triage strategies are not effective in correctly identifying patients suffering from acute coronary syndrome (ACS). The diagnostic workup of patients presenting with acute chest pain continues to represent a major challenge for emergency department (ED) personnel. This statement holds especially true for patients with a low to intermediate likelihood for ACS. Taking current concepts for the diagnosis and management of patients presenting with acute chest pain to the ED into account, this article discusses the evidence and potential role of coronary computed tomography angiography to improve management of patients with possible ACS.

Prognostic value of real time dobutamine stress myocardial contrast echocardiography in patients with chest pain syndrome

The aims of this study were (1) to evaluate the prognostic value of negative wall motion (WM) and myocardial perfusion during contrast-dobutamine stress echocardiography (DSE), (2) to determine whether WM-myocardial contrast echocardiography (MCE) had incremental prognostic value over just WM during DSE in patients with chest pain in the emergency room (ER), and (3) to compare the prognostic value of negative DSE-WM, and DSE-WM-MCE to nuclear-myocardial perfusion imaging (N-MPI) in a similar patient population over the same time period. We retrospectively studied 569 patients with real time contrast DSE, and 147 patients underwent N-MPI for evaluation of chest pain. Follow-up for cardiac events was obtained between 12 and 25 months. The cumulative cardiac event-free survival was 94.5% in negative DSE-WM, 97.1% in negative DSE-WM-MCE and 96.7% in negative N-MPI group. Cardiac event-free survival of the negative DSE-WM-MCE group was significantly higher than the DSE-WM group (log rank P < 0.01), and similar in the DSE-WM-MCE group compared to the N-MPI group. Combined WM and perfusion during DSE was the strongest independent predictor for cardiac events. The negative predictive power of DSE-WM-MCE is superior to that of just negative DSE-WM and is comparable to that of N-MPI. Myocardial perfusion and WM analysis during DSE provide independent information for predicting cardiac events in patients with chest pain syndrome in the ER.

Contrast stress-echocardiography predicts cardiac events in patients with suspected acute coronary syndrome but nondiagnostic electrocardiogram and normal 12-hour troponin

BACKGROUND

No large study has demonstrated that any stress test can risk-stratify future hard cardiac events (cardiac death or myocardial infarction) in patients with suspected acute coronary syndromes (ACS), nondiagnostic electrocardiographic (ECG) findings, and normal troponin levels. The aim of this study was to test the hypothesis that combined contrast wall motion and myocardial perfusion echocardiographic assessment (cMCE) during stress echocardiography can predict long-term hard cardiac events in patients with suspected ACS, nondiagnostic ECG findings, and normal troponin.

METHODS

A total of 545 patients referred for contrast stress echocardiography from the emergency department for suspected ACS but nondiagnostic ECG findings and normal troponin levels at 12 hours were followed up for cardiac events. Patients underwent dipyridamole-atropine echocardiography with adjunctive myocardial perfusion imaging using a commercially available ultrasound contrast medium (SonoVue).

RESULTS

During a median follow-up period of 12 months, 25 cardiac events (4.6%) occurred (no deaths, 12 nonfatal myocardial infarctions, 13 episodes of unstable angina). Abnormal findings on cMCE were the most significant predictor of both hard cardiac events (hazard ratio, 22.8; 95% confidence interval, 2.9-176.7) and the combined (cardiac death, myocardial infarction, or unstable angina requiring revascularization) end point (hazard ratio, 10.7; 95% confidence interval, 3.7-31.3). The inclusion of the cMCE variable significantly improved multivariate models, determining lower Akaike information criterion values and higher discrimination ability.

CONCLUSIONS

cMCE during contrast stress echocardiography provided independent information for predicting hard and combined cardiac events beyond that predicted by stress wall motion abnormalities in patients with suspected ACS, nondiagnostic ECG findings, and normal troponin levels.

Detection of intracoronary thrombus by magnetic resonance imaging in patients with acute myocardial infarction

BACKGROUND

Persistent intracoronary thrombus after plaque rupture is associated with an increased risk of subsequent myocardial infarction and mortality. Coronary thrombus is usually visualized invasively by x-ray coronary angiography. Non-contrast-enhanced T1-weighted magnetic resonance (MR) imaging has been useful for direct imaging of carotid thrombus and intraplaque hemorrhage by taking advantage of the short T1 of methemoglobin present in acute thrombus and intraplaque hemorrhage. The aim of this study was to investigate the use of non-contrast-enhanced MR for direct thrombus imaging (MRDTI) in patients with acute myocardial infarction.

METHODS AND RESULTS

Eighteen patients (14 men; age, 61±9 years) underwent MRDTI within 24 to 72 hours of presenting with an acute coronary syndrome before invasive x-ray coronary angiography; MRDTI was performed with a T1-weighted, 3-dimensional, inversion-recovery black-blood gradient-echo sequence without contrast administration. Ten patients were found to have intracoronary thrombus on x-ray coronary angiography (left anterior descending, 4; left circumflex, 2; right coronary artery, 4; and right coronary artery-posterior descending artery, 1), and 8 had no visible thrombus. We found that MRDTI correctly identified thrombus in 9 of 10 patients (sensitivity, 91%; posterior descending artery thrombus not detected) and correctly classified the control group in 7 of 8 patients without thrombus formation (specificity, 88%). The contrast-to-noise ratio was significantly greater in coronary segments containing thrombus (n=10) compared with those without visible thrombus (n=131; mean contrast-to-noise ratio, 15.9 versus 2.6; P<0.001).

CONCLUSION

Use of MRDTI allows selective visualization of coronary thrombus in a patient population with a high probability of intracoronary thrombosis.

Usefulness of contrast stress-echocardiography or exercise-electrocardiography to predict long-term acute coronary syndromes in patients presenting with chest pain without electrocardiographic abnormalities or 12-hour troponin elevation

The evaluation of patients presenting to the hospital with a recent episode of chest pain suggestive of myocardial ischemia, nondiagnostic electrocardiographic findings, and normal 12-hour cardiac troponin levels remains a challenge for the clinician. We selected 1,081 consecutive patients who presented to the emergency department during 2008 for a chest pain complaint of suspected cardiac origin without significant electrocardiographic abnormalities or troponin elevation. These patients underwent either contrast-enhanced stress-echocardiography with myocardial perfusion imaging or exercise-electrocardiography within 5 days of the index admission. We analyzed their 1-year cardiac outcome (i.e., unstable angina, myocardial infarction, or cardiac death). A post test likelihood of cardiac events was determined on the basis of the results of the provocative testing. Significantly better event-free survival (log-rank p <0.0001) was found for both hard (cardiac death and nonfatal myocardial infarction) and combined (acute coronary syndrome) end points in patients with normal contrast-enhanced stress-echocardiographic findings. However, this was not the case for patients in the exercise-electrocardiographic group, for whom event-free survival was not significantly different among the 3 possible result categories (normal, indeterminate, and abnormal test findings; log-rank p = NS). In conclusion, inducible ischemia detected by contrast-enhanced stress-echocardiography predicted the 1-year incidence of acute coronary syndrome (11.3% for positive vs 0.8% for negative results). However, this was not the case for exercise-electrocardiography, with a 2.7%, 2.3%, and 2.9% 1-year incidence of acute coronary syndromes for positive, negative, and indeterminate results, respectively.

Diagnostic value of coronary artery calcium scoring in low-intermediate risk patients evaluated in the emergency department for acute coronary syndrome

Early and accurate triage of patients with possible ischemic chest pain remains challenging in the emergency department because current risk stratification techniques have significant cost and limited availability. The aim of this study was to determine the diagnostic value of the coronary artery calcium score (CACS) for the detection of obstructive coronary artery disease (CAD) in low- to intermediate-risk patients evaluated in the emergency department for suspected acute coronary syndromes. A total of 225 patients presenting to the emergency department with acute chest pain and Thrombolysis In Myocardial Infarction (TIMI) scores <4 who underwent non-contrast- and contrast-enhanced coronary computed tomographic angiography were included. CACS was calculated from the noncontrast scan using the Agatston method. The prevalence of obstructive CAD (defined from the contrast scan as ≥ 50% maximal reduction in luminal diameter in any segment) was 9% and increased significantly with higher scores (p <0.01 for trend). CACS of 0 were observed in 133 patients (59%), of whom only 2 (1.5%) had obstructive CAD. The diagnostic accuracy of CACS to detect obstructive CAD was good, with an area under the receiver-operating characteristic curve of 0.88 and a negative predictive value of 99% for a CACS of 0. In a multivariate model, CACS was independently associated with obstructive CAD (odds ratio 7.01, p = 0.02) and provided additional diagnostic value over traditional CAD risk factors. In conclusion, CACS appears to be an effective initial tool for risk stratification of low- to intermediate-risk patients with possible acute coronary syndromes, on the basis of its high negative predictive value and additive diagnostic value.

Prognostic value of adenosine stress cardiovascular magnetic resonance in patients with low-risk chest pain

BACKGROUND

Approximately 5% of patients with an acute coronary syndrome are discharged from the emergency room with an erroneous diagnosis of non-cardiac chest pain. Highly accurate non-invasive stress imaging is valuable for assessment of low-risk chest pain patients to prevent these errors. Adenosine stress cardiovascular magnetic resonance (AS-CMR) is an imaging modality with increasing application. The goal of this study was to evaluate the negative prognostic value of AS-CMR among low-risk acute chest pain patients.

METHODS

We studied 103 patients, mean 56.7 + or - 12.3 years of age, with chest pain and no electrocardiographic evidence of ischemia and negative cardiac biomarkers of necrosis, who were admitted to the Cardiac Decision Unit of our institution. All patients underwent AS-CMR. A negative AS-CMR was defined as absence of all the following: regional wall motion abnormalities at rest; perfusion defects during stress (adenosine) and rest; and myocardial scar on late gadolinium enhancement images. The patients were followed for a mean of 277 (range 161-462) days. The primary end point was defined as the combination of cardiac death, nonfatal acute myocardial infarction, re-hospitalization for chest pain, obstructive coronary artery disease (>50% coronary stenosis on invasive angiography) and coronary revascularization.

RESULTS

In 14 patients (13.6%), AS-CMR was positive. The remaining 89 patients (86.4%), who had negative AS-CMR, were discharged. No patient with negative AS-CMR reached the primary end-point during follow-up. The negative predictive value of AS-CMR was 100%.

CONCLUSION

AS-CMR holds promise as a useful tool to rule out significant coronary artery disease in patients with low-risk chest pain. Patients with negative AS-CMR have an excellent short and mid-term prognosis.

Predictive value of normal dobutamine stress echocardiogram in patients with low-risk acute chest pain

Dobutamine stress echocardiography (DSE) has been proposed as a tool for risk stratification of patients with acute chest pain (ACP). In this single-center study, we evaluated the negative predictive value of DSE in 178 patients who presented with low-risk ACP (normal or inconclusive electrocardiogram and negative markers of myocardial damage) and were discharged following a maximal DSE that did not reveal ischemia. During the follow-up (median 321 days), 2 of the 178 patients were admitted with an acute coronary syndrome and were diagnosed with obstructive coronary artery disease at angiography. In the time frame of the study, the negative predictive value of a normal and maximal DSE for an adverse cardiac event was 98.9% (95% CI: 96.0-99.8%). Thus, a normal DSE has a high negative predictive value and comprises a safe and effective tool for early risk stratification of patients who present with acute chest pain of low risk.

Effect on quality of life of different accelerated diagnostic protocols for management of patients presenting to the emergency department with acute chest pain

This study assessed the effects on quality of life (QoL) of dobutamine-atropine stress echocardiography (DASE) and electrocardiogram exercise testing (EET) accelerated diagnostic protocols for early stratification of low-risk patients with acute chest pain (ACP). A total of 290 patients with ACP, a nondiagnostic electrocardiogram, and negative biomarkers were randomly assigned to an accelerated diagnostic protocol (DASE, n = 110, or EET, n = 89) or usual care (n = 91) and followed up for 2 months. QoL was assessed at discharge and 2-month follow-up using the Nottingham Health Profile questionnaire. Baseline and 2-month follow-up answers to the Nottingham Health Profile questionnaire were available for 207 patients (71%; 55 in the usual-care, 77 in the DASE, and 75 in the ETT arm). At predischarge, patients in the usual-care arm reported higher impairment in the physical mobility and pain dimensions compared with the DASE and EET arms (p = 0.019 and p = 0.023, respectively). At 2-month follow-up, QoL improved in all groups; however, patients in the usual-care arm had significantly worse scores than patients managed using accelerated diagnostic protocols in the physical mobility, pain, social isolation, emotional reactions, and energy level dimensions (p = 0.014, p = 0.002, p = 0.04, p = 0.01, and p = 0.003, respectively). In conclusion, low-risk patients with ACP had non-negligible impairment of QoL in the acute phase. Emergency department ADPs with early DASE and EET reduced QoL impairment at both baseline and 2-month follow-up.

Cardiovascular risk in women with non-specific chest pain (from the Women's Health Initiative Hormone Trials)

Women discharged with diagnoses of nonspecific chest pain (NSCP) may be at increased risk for subsequent coronary artery disease (CAD) events. The influence of hormone therapy on NSCP is unknown. The Women's Health Initiative (WHI) enrolled postmenopausal women aged 50 to 79 years. The duration of follow-up was 7.1 years in the WHI Estrogen-Alone trial (E-Alone) and 5.6 years in the WHI Estrogen Plus Progestin trial (E+P). After excluding women with previous cardiovascular disease, 9,427 women in E-Alone and 15,105 women in E+P were included in this analysis. NSCP, defined as having a primary hospital discharge diagnosis of NSCP by International Classification of Diseases, Ninth Revision, code, was reported in 322 women in E-Alone and 249 in E+P. Risks for subsequent CAD events were estimated using intent-to-treat Cox proportional-hazards models stratified by clinic and adjusted for age and other risk factors. In the fully adjusted models of the combined trials, women with NSCP had a twofold greater risk for subsequent nonfatal CAD events, including nonfatal myocardial infarction (2.3% vs 1.7%, hazard ratio [HR] 2.10, 95% confidence interval [CI] 1.11 to 3.98), revascularization (3.5% vs 2.6%, HR 1.99, 95% CI 1.20 to 3.30), and hospitalized angina (3.7% vs 2.3%, HR 2.39, 95% CI 1.46 to 3.92). Hormone therapy did not appear to have a significant effect on either the incidence of NSCP hospitalizations (E-Alone: HR 1.04, 95% CI 0.81 to 1.32; E+P: HR 0.78, 95% CI 0.59 to 1.02) or the risk for a subsequent CAD event. In conclusion, a hospitalization for NSCP doubles the risk for a subsequent CAD event in postmenopausal women over the next 5 to 7 years and identifies them as candidates for aggressive risk factor treatment.

Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the potential of adding - coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage from the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence upon operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

Economic analysis including long-term risks and costs of alternative diagnostic strategies to evaluate patients with chest pain

BACKGROUND

Diagnosis costs for cardiovascular disease waste a large amount of healthcare resources. The aim of the study is to evaluate the clinical and economic outcomes of alternative diagnostic strategies in low risk chest pain patients.

METHODS

We evaluated direct and indirect downstream costs of 6 strategies: coronary angiography (CA) after positive troponin I or T (cTn-I or cTnT) (strategy 1); after positive exercise electrocardiography (ex-ECG) (strategy 2); after positive exercise echocardiography (ex-Echo) (strategy 3); after positive pharmacologic stress echocardiography (PhSE) (strategy 4); after positive myocardial exercise stress single-photon emission computed tomography with technetium Tc 99m sestamibi (ex-SPECT-Tc) (strategy 5) and direct CA (strategy 6).

RESULTS

The predictive accuracy in correctly identifying the patients was 83,1% for cTn-I, 87% for cTn-T, 85,1% for ex-ECG, 93,4% for ex-Echo, 98,5% for PhSE, 89,4% for ex-SPECT-Tc and 18,7% for CA. The cost per patient correctly identified results $2.051 for cTn-I, $2.086 for cTn-T, $1.890 for ex-ECG, $803 for ex-Echo, $533 for PhSE, $1.521 for ex-SPECT-Tc ($1.634 including cost of extra risk of cancer) and $29.673 for CA ($29.999 including cost of extra risk of cancer). The average relative cost-effectiveness of cardiac imaging compared with the PhSE equal to 1 (as a cost comparator), the relative cost of ex-Echo is 1.5x, of a ex-SPECT-Tc is 3.1x, of a ex-ECG is 3.5x, of cTnI is x3.8, of cTnT is x3.9 and of a CA is 56.3x.

CONCLUSION

Stress echocardiography based strategies are cost-effective versus alternative imaging strategies and the risk and cost of radiation exposure is void.

Comparison of early dobutamine stress echocardiography and exercise electrocardiographic testing for management of patients presenting to the emergency department with chest pain

This study compared the cost-effectiveness of dobutamine-atropine stress echocardiography (DASE) and electrocardiographic exercise testing (EET) implemented in emergency department accelerated diagnostic protocols for the early stratification of low-risk patients presenting with acute chest pain (ACP). One hundred ninety-nine patients with ACP, nondiagnostic electrocardiographic results, and negative biomarker results were randomized to DASE (n = 110) or EET (n = 89) <6 hours after emergency department presentation. Patients with negative risk assessment results were immediately discharged and followed for 2 months. Ninety patients (82%) in the DASE arm and 78 (88%) in the EET arm were discharged after the diagnosis of nonischemic ACP. The mean lengths of stay in the hospital were 23 +/- 12 and 31 +/- 23 hours in the DASE and EET arms, respectively (p = 0.01). No 2-month follow-up events occurred in DASE patients, and the event rate was significantly higher in EET patients (0% vs 11%, p = 0.004). The DASE strategy showed lower costs compared with the EET strategy at 1-month ($1,026 +/- $250 vs $1,329 +/- $1,288, p = 0.03) and 2-month ($1,029 +/- 253 vs $1,684 +/- $2,149, p = 0.005) follow-up. In conclusion, early DASE in emergency department triage of low-risk patients with ACP is safe and reduces costs of care compared to EET.

The role of cardiovascular imaging techniques in the assessment of patients with acute chest pain

Chest pain is the most common presenting symptom of coronary artery disease. The assessment and appropriate management of patients with acute chest pain and non-diagnostic electrocardiograms (ECGs) remain a continuing clinical problem, with major logistic and financial implications for health-care providers. Cardiovascular imaging is at the forefront of health care, experiencing rapid changes over the recent years, particularly with the use of advanced medical technologies. Imaging techniques like acute rest myocardial perfusion imaging (MPI), echocardiography, electron beam computed tomography (CT), cardiac magnetic resonance imaging (MRI) and multi-detector CT (MDCT) have been used recently in the evaluation and triage of patients with chest pain in addition to the conventional investigations such as ECGs and cardiac biomarkers in the chest pain units. The annual potential cost savings, by incorporating the routine use of acute rest MPI in patients with low-to-moderate risk and non-diagnostic ECGs are substantial. The high negative predictive value of a normal resting MPI in patients with chest pain for myocardial infarction and future cardiac events is well established. Echocardiography is also considered to be useful but the technique is operator dependent and at present there is insufficient data to support its use. Cardiac MRI is expensive and time consuming and there is insufficient diagnostic and prognostic data to make it suitable for chest pain patients at present. There has been increasing interest in MDCT recently, especially with the advent of 64-slice CT but the sensitivity and specificity in chest pain patients are no better than MPI so far.

Contrast ultrasound in the assessment of patients presenting with suspected cardiac ischemia

Echocardiography is a portable technology that can be used to assess myocardial, pericardial, and valvular structure and function. Doppler echocardiography provides the ability to evaluate blood flow in large vessels and within cardiac chambers. Recently, the advent of microbubble contrast agents, which can opacify the systemic circulation, has improved the ability of echocardiography to evaluate left-ventricular function by improving delineation of the left-ventricular endocardial border. Furthermore, these microbubbles can be used to assess myocardial perfusion and quantify myocardial blood flow. Myocardial contrast echocardiography has been studied in multiple clinical situations, including the acute evaluation of patients presenting with suspected cardiac ischemia. Ongoing research is focused on the development of microbubbles that are capable of detecting molecular and cellular events within the circulation, which may allow distinction of acute vs. remote ischemic insults to the myocardium. This multifaceted technology promises to be of increasing clinical utility--not only for the heart, but for any organ accessible to ultrasound.

The Impact of B-Type Natriuretic Peptide in Addition to Troponin I, Creatine Kinase-MB, and Myoglobin on the Risk Stratification of Emergency Department Chest Pain Patients With Potential Acute Coronary Syndrome

STUDY OBJECTIVE

The emergency department (ED) evaluation of chest pain patients with potential acute coronary syndrome is limited by the initial sensitivity of cell injury markers. BNP is increased during myocardial ischemia and is associated with adverse outcomes. We determine whether the addition of B-type natriuretic peptide (BNP) to troponin I, creatine kinase-MB (CK-MB), and myoglobin increases the sensitivity and negative predictive value (NPV) for acute myocardial infarction, acute coronary syndrome, and 30-day adverse events among chest pain patients with potential acute coronary syndrome.

METHODS

A convenience sample of patients aged 30 years or older and presenting to an urban academic ED with nontraumatic chest pain, thus prompting an ECG, was enrolled, and consent was obtained. Blood samples were drawn at 0 and 90 minutes. Thirty-day follow-up was performed for all enrolled patients. Main outcomes were acute myocardial infarction, acute coronary syndrome, and 30-day events (death, acute myocardial infarction, or revascularization). BNP cutoffs were derived from receiver operator characteristics curves. The sensitivity, specificity, positive predictive value (PPV), and NPV with 95% confidence intervals (CIs) were calculated with and without BNP. Differences in sensitivity and specificity with the addition of BNP were calculated with 95% CIs, and McNemar's test was performed to compare sensitivities and specificities.

RESULTS

Four hundred twenty-six patients were enrolled and analyzed. The cohort was 54.7+/-13.9 years old, 47.7% men, and 63.5% black. The outcomes were acute myocardial infarction, 39 (9.2%), acute coronary syndrome, 101 (23.7%), and 30-day adverse cardiovascular events 52 (12.2%). BNP cutoffs derived were 51, 31, and 31 pg/mL for acute myocardial infarction, acute coronary syndrome, and 30-day events, respectively. The addition of BNP showed increased sensitivity at the cost of decreased specificity for all 3 outcomes, as follows: (1) acute myocardial infarction: sensitivity: 87.2% (95% CI 72.6% to 95.7%) to 97.4% (95% CI 86.5% to 100%), difference 10.3% (95% CI-0.2% to 24.6%), P=.125; specificity: 62.3% (95% CI 57.2% to 67.1%) to 47.8% (95% CI 42.7% to 52.9%), difference 14.5% (95% CI 11.1% to %18.4), P<.0001; (2) acute coronary syndrome: sensitivity: 75.2% (95% CI 65.7% to 83.3%) to 88.1% (95% CI 80.2% to 93.7%), difference 12.9% (95% CI 7.0% to 21.0%), P=.0002; specificity: 68.0% (95% CI 62.6% to 73.0%) to 48.6% (95% CI 43.1% to 54.2%), difference 19.4% (95% CI 15.2% to 24.1%), P<.0001; (3) 30-day events: sensitivity: 71.2% (95% CI 56.9% to 82.9%) to 88.5% (95% CI 76.6% to 95.7%), difference 17.3% (95% CI 7.7% to 30.3%), P=.004; specificity: 61.8% (95% CI 56.6% to 66.7%) to 43.9% (95% CI 38.8% to 49.0%), difference 17.9% (95% CI 14.2% to 22.2%), P<.0001. There were trends toward increased NPV and decreased PPV for all outcomes, and the addition of BNP achieved a NPV of 99.5% (95% CI 97.0% to 100%) compared with 98.0% (95% CI 95.3% to 99.3%) for acute myocardial infarction.

CONCLUSION

The addition of BNP as a dichotomous test to troponin I, CK-MB, and myoglobin produces increased sensitivity at a cost of decreased specificity for acute myocardial infarction, acute coronary syndrome, and 30-day adverse events. Because of this tradeoff, BNP cannot be recommended for use among all ED chest pain patients. However, the improved sensitivity may make this test useful in selected cohorts when the decreased specificity is less important.