Emergency Department Chest Pain Patients Research Articles

Ensemble-Based Risk Scoring with Extreme Learning Machine for Prediction of Adverse Cardiac Events

Accurate prediction of adverse cardiac events for the emergency department (ED) chest pain patients is essential in risk stratification due to the current ambiguity in diagnosing acute coronary syndrome. While most current practices rely on human decision by measuring clinical vital signs, computerized solutions are gaining popularity. We have previously proposed an ensemble-based scoring system (ESS). In this paper, we aim to extend the ESS system using extreme learning machine (ELM), a fast learning algorithm for neural networks. We recruited patients from the ED of Singapore General Hospital, and extracted features such as heart rate variability, 12-lead ECG parameters, and vital signs. We also proposed a novel algorithm called ESS-ELM to predict adverse cardiac events. Different from the original ESS algorithm, ESS-ELM uses the under-sampling technique only in model training. Our proposed method was compared to the original ESS algorithm and several clinical scores in predicting patient outcome. With a cohort of 797 recruited patients, we demonstrated that ESS-ELM outperformed the original ESS algorithm and three established clinical scores, namely HEART, TIMI, and GRACE, in terms of receiver operating characteristic analysis. Furthermore, we have investigated the impact of hidden node number and ensemble size on the predictive performance. ELM has demonstrated the flexibility in its integration with the ESS algorithm. Experiments showed the value of ESS-ELM in prediction of adverse cardiac events. Future works may include the use of new ELM-based learning methods and further validation with a new cohort of patients.

Interpretation of Positive Troponin Results Among Patients with and Without Myocardial Infarction

Measuring cardiac troponins is integral to diagnosing acute myocardial infarction (AMI); however, troponins may be elevated without AMI, and the use of multiple different assays confounds comparisons. We considered characteristics and serial troponin values in emergency department chest pain patients with and without AMI to interpret troponin excursions. We compared serial troponin in 124 AMI and non-AMI patients from the observational Performance of Triage Cardiac Markers in the Clinical Setting (PEARL) study who presented with chest pain and had at least one troponin value exceeding the 99th percentile of normal. Because 8 assays were used during data collection, we employed a method of scaling the troponin value to the corresponding assay's 99th percentile upper reference limit to standardize the results. In 81 AMI patients, 96% had elevated troponin at the first test following initial elevation, compared to 73% of the 43 non-AMI patients (P < 0.001). Scaling troponin to the 99th percentile of normal yielded a median value that was 4.8 [2.2, 14.1] times higher than the 99th percentile cutpoint among AMI patients, compared to 2.3 [1.5, 6.5] times higher among non-AMI patients (P = 0.04). The rise in serial scaled troponin values distinguished the AMI patients. Scaling to the 99th percentile was useful for comparing troponin when different assays were utilized.

73 Early Exclusion of Major Adverse Cardiac Events in Emergency Department Chest Pain Patients: Prospective Observational Study

The current evaluation of chest pain patients presenting to an emergency department (ED) with suspected acute coronary syndrome (ACS) is a lengthy process involving serial measurements of troponin. We aimed to validate the diagnostic accuracy of combinations of the Thrombolysis in Myocardial Infarction (TIMI) score with a single high-sensitivity cardiac troponin T (hs-cTnT) assay within 2 hours of ED arrival for the early rule-out of 30-day major adverse cardiac events (MACE), and to compare the TIMI score with combinations of heart-type fatty acid binding protein (H-FABP) and a modified HEART score. 602 consecutive adult patients with chest pain (ST-elevation myocardial infarction was excluded) and suspected ACS were recruited with TIMI and HEART scores, and point-of-care H-FABP test performed. MACE occurred in 42 (7.0%) patients within 30 days. A modified TIMI score of zero alone identified 65 (11%) patients, and a HEART score ≤2 identified 96 (16%) patients, as having low risk for 30-day MACE. No MACE occurred in these groups giving both scores a sensitivity and negative predictive value of 100% (95% CI 91.6-100%), and respectively a specificity of 11.6% (95% CI 9.2-14.5%) and 17.1% (95% CI 14.2-20.5%). Use of both TIMI and HEART scores improved specificity further to 22.0% (95% CI 18.7-25.6%). Early H-FABP had a sensitivity of 41.5% (95% CI 27.8-56.6%) and a specificity of 91.1% (95% CI 88.4-93.2%). A modified TIMI score of zero or a HEART score of ≤2, incorporating a single hs-cTnT level, will identify patients with low risk of 30-day MACE for early discharge within 2 hours of ED arrival.

Diagnostic Accuracy of High-Sensitivity Cardiac Troponin T at Presentation Combined With History and ECG for Ruling Out Major Adverse Cardiac Events

We evaluate the diagnostic accuracy of a high-sensitivity cardiac troponin T (hs-cTnT) level less than 5ng/L or less than or equal to 14 ng/L at emergency department (ED) presentation, combined with the emergency physician's assessment of history and ECG, for ruling out major adverse cardiac events within 30 days. This prospective observational study enrolled consecutive ED chest pain patients. Emergency physicians' assessments of patient history and ECG were collected. The primary outcome was 30-day major adverse cardiac events, defined as acute myocardial infarction, unstable angina, cardiogenic shock, ventricular arrhythmia, atrioventricular block, cardiac arrest, or death of cardiac or unknown cause. A total of 1,138 patients were included in the final analysis. The combination of hs-cTnT less than 5 ng/L, anonischemic ECG result, and a nonhigh risk history was present for 29.2% of all patients and had a sensitivity of 99.2% (95% confidence interval [CI] 95.6% to 100%), negative predictive value (NPV) of 99.7% (95% CI 98.3% to 100%), and anegative likelihood ratio of 0.02 (95% CI 0 to 0.17) for 30-day major adverse cardiac events. The same combination withhs-cTnT less than or equal to 14 ng/L was present in 66.7% of the patients and had a sensitivity of 92% (95% CI 85.8% to 96.1%), NPV of 98.7% (95% CI 97.6% to 99.4%), and negative likelihood ratio of 0.11 (95% CI 0.06 to 0.20). A single hs-cTnT result of less than 5 ng/L at ED presentation when combined with a nonischemic ECG result and a nonhigh risk history identified 29% of chest pain patients at a very low risk of 30-day major adverse cardiac events. A similar strategy with hs-cTnT less than or equal to 14 ng/L was associated with a higher miss rate.

The HEART score with high-sensitive troponin T at presentation: ruling out patients with chest pain in the emergency room.

The HEART score is a simple scoring system, ranging from 0 to 10, specifically developed for risk stratification of patients with undifferentiated chest pain. It has been validated for the conventional troponin, but not for high-sensitive troponin. We assess a modified version of the HEART score using a single high-sensitivity troponin T dosage at presentation, regardless of symptom duration, and with different ECG criteria to evaluate if the patients with a low HEART score could be safely discharged early. The secondary aim was to confirm a statistically significant difference in each HEART score group (low 0-3, intermediate 4-6, high 7-10) in the occurrence of major adverse cardiac events at 30 and 180days. We retrospectively analyzed the HEART score of 1597 consecutive patients admitted to the Emergency Department of our Hospital for chest pain between January 1 and June 30, 2014. Of these, 190 did not meet the inclusion criteria and 29 were lost to follow-up. None of the 512 (37.2%) patients with a low HEART score had an event within 180days. The difference between the cumulative incidences of events in the three HEART score groups was statistically significant (P<0.0001). We demonstrate that it might be possible to safely discharge Emergency Department chest pain patients with a low modified HEART score after an initial determination of high-sensitive troponin T, without a prolonged observation period or an additional cardiac testing.

PL001: Derivation of a 2-hour high-sensitivity troponin T algorithm for rapid rule-out of acute myocardial infarction in emergency department chest pain patients

Introduction: Chest pain and symptoms of acute coronary syndrome are responsible for a large proportion of ED visits and acute hospitalizations. However, only about 15% of patients presenting to the ED with high-risk symptoms do, in fact, have an acute coronary syndrome. The objective of this study is to derive a 2-hour high-sensitivity Troponin T (hsTnT) testing algorithm with outcome based-cutoffs to rapidly rule out acute myocardial infarction (AMI) in a large proportion of ED chest pain patients. Methods: Patients included consecutive ED patients with a chief complaint of cardiac chest pain who had an hsTnT assay performed at ED arrival and 2 hours after ED arrival. Administrative databases were queried to identify troponin results and major adverse cardiac outcomes (MACE) including death, MI, and revascularization. Test characteristics of iterative combinations of initial troponin level and absolute change in troponin level were quantified in order to identify the testing algorithm that identified the greatest proportion of patients eligible for early discharge while maintaining a target sensitivity of 98.5% for the primary outcome of 7-day AMI. Results: 755 eligible patients had hsTnT assays performed at ED arrival and at 2 hours. 91 patients (12.1%) had a 7-day AMI while 108 (14.0%) had 7-day MACE. An initial hsTnT level of less than 14 ng/L, in combination with a 2-hour absolute change of less than 10ng/L had a sensitivity of 98.9% (95% CI 94.0,99.8) and an NPV of 99.8% (95% CI 98.7, 100.0) for 7-day AMI. This identified 58.5% of all patients as being suitable for early discharge. Sensitivity and NPV for 7-day MACE were 90.0% (95% CI 83.3, 94.2) and 97.3% (95% CI 95.3,98.4) respectively. Sex-specific differences in test characteristics were not clinically important. Rule-in hsTnT cutoffs were also evaluated, with specificities ranging from 85-95%, although cutoffs with higher specificity had less ability to rapidly rule-in AMI, leaving more patients with indeterminate results after 2 hours. Conclusion: A hsTnT algorithm can safely and accurately rule out AMI in 58.5% of ED chest pain patients within 2 hours of ED arrival. The lower sensitivity of this algorithm for MACE compared to AMI speaks to the importance of clinical assessment and ECG findings in identifying patients at risk for acute coronary syndromes.

NON-INVASIVE CALCULATION OF FRACTIONAL FLOW RESERVE FOR RECLASSIFICATION OF POTENTIALLY HEMODYNAMICALLY-SIGNIFICANT CORONARY ARTERY DISEASE BY CORONARY COMPUTED TOMOGRAPHY ANGIOGRAPHY IN EMERGENCY DEPARTMENT CHEST PAIN PATIENTS

Multicenter trials demonstrated the efficacy and efficiency of coronary CT angiography (CCTA) for evaluation of low to intermediate risk emergency department (ED) chest pain patients but showed an increase in testing after CCTA. CT derived fractional flow reserve (FFR-CT) has been shown to be

Discriminative Power of the HEART Score for Obstructive Coronary Artery Disease in Acute Chest Pain Patients Referred for CCTA.

To investigate the ability of the HEART score to predict the presence of obstructive coronary artery disease (CAD) determined by coronary computed tomography angiography (CCTA) and its ability to predict the occurrence of major adverse cardiac events (MACE) in patients referred for CCTA after emergency department (ED) presentation. From December 2011 to August 2014, 710 ED patients with chest pain who underwent CCTA within 30 days were included. The HEART score was retrospectively calculated and patients were followed for MACE, comprised of death, myocardial infarction, and revascularization. Association of CAD at CCTA in the different categories of the HEART score was analyzed using χ test. The performance of the HEART score in discriminating between those with and without obstructive CAD was evaluated by receiver operating characteristics. Kaplan-Meier analysis was used to assess MACE-free survival stratified by HEART-score categories. During median follow-up of 826 days (interquartile range: 563-1056), MACE occurred in 46 (6.5%) patients; 3 (0.4%) myocardial infarction, 8 (1.1%) death, and 36 (5.1%) revascularizations. A low HEART score was a significant predictor for MACE-free survival (P = 0.010). CCTA revealed obstructive CAD in 11.7% of patients, with no significant difference between patients with a low and intermediate/high HEART score, respectively 10.7% and 13.2% (P = 0.29). The ability of the HEART score to identify obstructive CAD was poor with an AUC of the receiver operating characteristics curve of 0.53. The HEART score does not adequately identify patients with obstructive CAD at CCTA. It does however predict occurrence of MACE in medium-term follow-up. Excluding patients from additional testing based solely on a low HEART score may lead to suboptimal patient management. CCTA had important implications on patient management and may be a more appropriate tool to further stratify risk in ED chest pain patients.

Validation of the HEART score in Indian population

Objectives Chest pain is a common presentation to the Emergency department (ED) where an acute coronary syndrome needs to be differentiated from other causes of chest pain. In a busy ED, we need an objective method to risk stratify patients quickly, using minimum resources. There are various scoring methods used for this, but none exclusively for ED patients except the HEART score. HEART score stands for History, ECG, Age, Risk factors, and Troponin I where each component is scored from 0 to 2. The goal of this study was to determine a correlation between clinical judgement, HEART score and outcomes in all patients presenting with chest pain to the ED and validate the accuracy of the HEART score in risk stratifying ED chest pain patients.

Diagnosis of Aortic Dissection in Emergency Department Patients is Rare.

IntroductionAortic dissection is a rare event. While the most frequent symptom is chest pain, that is a common emergency department (ED) chief complaint and other diseases causing chest pain occur much more often. Furthermore, 20% of dissections are without chest pain and 6% are painless. For these reasons, diagnosing dissections may be challenging. Our goal was to determine the number of total ED and atraumatic chest pain patients for every aortic dissection diagnosed by emergency physicians.MethodsDesign: Retrospective cohort. Setting: 33 suburban and urban New York and New Jersey EDs with annual visits between 8,000 and 80,000. Participants: Consecutive patients seen by emergency physicians from 1-1-1996 through 12-31-2010. Observations: We identified aortic dissection and atraumatic chest pain patients using the International Classification of Diseases 9th Revision and Clinical Modification codes. We then calculated the number of total ED and atraumatic chest pain patients for every aortic dissection, along with 95% confidence intervals (CIs).ResultsFrom a database of 9.5 million ED visits, we identified 782 aortic dissections or one for every 12,200 (95% CI [11,400–13,100]) visits. The mean age of dissection patients was 66±16 years and 38% were female. There were 763,000 (8%) with atraumatic chest pain diagnoses. Thus, there is one dissection for every 980 (95% CI [910–1,050]) atraumatic chest pain patients.ConclusionThe diagnosis of aortic dissections by emergency physicians is rare and challenging. An emergency physician seeing 3,000 to 4,000 patients a year would diagnose an aortic dissection approximately every three to four years.

Safety and efficiency of outpatient versus emergency department-based coronary CT angiography for evaluation of patients with potential ischemic chest pain

BackgroundWhile coronary CT angiography (coronary CTA) may be comparable to standard care in diagnosing acute coronary syndrome (ACS) in emergency department (ED) chest pain patients, it has traditionally been obtained prior to ED discharge and a strategy of delayed outpatient coronary CTA following an ED visit has not been evaluated. ObjectiveTo investigate the safety of discharging stable ED patients and obtaining outpatient CCTA. MethodsAt two urban Canadian EDs, patients up to 65 years with chest pain but no findings indicating presence of ACS were further evaluated depending upon time of presentation: (1) ED-based coronary CTA during normal working hours, (2) or outpatient coronary CTA within 72 hours at other times. All data were collected prospectively. The primary outcome was the proportion of patients who had an outpatient coronary CTA ordered and had a predefined major adverse cardiac event (MACE) between ED discharge and outpatient CT; secondary outcome was the ED length of stay in both groups. ResultsFrom July 1, 2012 to June 30, 2014, we enrolled 521 consecutive patients: 350 with outpatient CT and 171 with ED-based CT. Demographics and risk factors were similar in both cohorts. No outpatient CT patients had a MACE prior to coronary CTA. (0.0%, 95% CI 0 to 0.9%) The median length of stay for ED-based evaluation was 6.6 hours (interquartile range 5.4 to 8.3 hours) while the outpatient group had a median length of stay of 7.0 hours (IQR 6.0 to 9.8 hours, n.s.). ConclusionsIn ED chest pain patients with a low risk of ACS, performing coronary CTA as an outpatient may be a safe strategy.

What is the Yield of Testing for Coronary Artery Disease after an Emergency Department Attendance with Chest Pain?

Guidelines recommend testing for coronary artery disease (CAD) for emergency department (ED) patients with a negative workup for acute coronary syndrome (ACS). The rationale is that, although myocardial infarction has been ruled out, the presentation could still indicate cardiac ischaemia. Evidence supporting this recommendation is weak. Planned sub-study of prospective cohort study of ED chest pain patients with a negative ACS workup who were discharged. Primary outcome of interest was occurrence of major adverse cardiac events (MACE) within 30 days. Secondary outcomes were rate of combined MACE or revascularisation and rates and outcome of referral for CAD testing. Analyses were descriptive. 742 patients were included; median age 56, 52% male. There were two MACE within 30 days (0.3%; 95% CI 0.07-1%). Two patients had revascularisation without ACS - combined MACE or revascularisation rate 0.5% (95% CI 0.2-1.4%). Seventy-five per cent of patients with adverse events had previously known CAD. There was no statistically significant difference in outcome between those referred for testing and those who were not. Age, TIMI score 0-1 and absence of known CAD performed well as potential discriminators for selective testing. In our study the rate of MACE within 30 days was very low, coronary intervention was rare and most patients with MACE or revascularisation had previously known CAD. For young patients, those without known CAD and those with a low TIMI score, the risk of clinically significant CAD appears to be very low. It adds to the case for abandoning routine testing for CAD.

Diagnostic values of chest pain history, ECG, troponin and clinical gestalt in patients with chest pain and potential acute coronary syndrome assessed in the emergency department.

In the assessment of chest pain patients with suspected acute coronary syndrome (ACS) in the emergency department (ED), physicians rely on global diagnostic impressions (‘gestalt’). The aim of this study was to determine the diagnostic value of the ED physician’s overall assessment of ACS likelihood, and the values of the main diagnostic modalities underlying this assessment, namely the chest pain history, the ECG and the initial troponin result. 1,151 consecutive ED chest pain patients were prospectively included. The ED physician’s interpretation of the chest pain history, the ECG, and the global likelihood of ACS were recorded on special forms. The discharge diagnoses were retrieved from the medical records. A chart review was carried out to determine whether patients with a non-ACS diagnosis at the index visit had ACS or suffered cardiac death within 30 days. The gestalt was better than its components both at ruling in (“Obvious ACS”, LR 29) and at ruling out (“No Suspicion of ACS”, LR 0.01) ACS. In the “Strong suspicion of ACS” group, 60% of the patients did not have ACS. A positive TnT (LR 24.9) and an ischemic ECG (LR 8.3) were strong predictors of ACS and seemed superior to pain history for ruling in ACS. In patients with a normal TnT and non-ischemic ECG, chest pain history typical of AMI was not a significant predictor of AMI (LR 1.9) while pain history typical of unstable angina (UA) was a moderate predictor of UA (LR 4.7). Clinical gestalt was better than its components both at ruling in and at ruling out ACS, but overestimated the likelihood of ACS when cases were assessed as strong suspicion of ACS. Among the components of the gestalt, TnT and ECG were superior to the chest pain history for ruling in ACS, while pain history was superior for ruling out ACS.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-015-0992-9) contains supplementary material, which is available to authorized users.

Prospective external validation of an accelerated (2-h) acute coronary syndrome rule-out process using a contemporary troponin assay.

BackgroundRecently there have been efforts to derive safe, efficient processes to rule out acute coronary syndrome (ACS) in emergency department (ED) chest pain patients. We aimed to prospectively validate an ACS assessment pathway (the 2-Hour Accelerated Diagnostic Protocol to Assess Patients with Chest Pain Symptoms Using Contemporary Troponins as the Only Biomarker (ADAPT) pathway) under pragmatic ED working conditions.MethodsThis prospective cohort study included patients with atraumatic chest pain in whom ACS was suspected but who did not have clear evidence of ischaemia on ECG. Thrombolysis in myocardial infarction (TIMI) score and troponin (TnI Ultra) were measured at ED presentation, 2 h later and according to current national recommendations. The primary outcome of interest was the occurrence of major adverse cardiac events (MACE) including prevalent myocardial infarction (MI) at 30 days in the group who had a TIMI score of 0 and had presentation and 2-h TnI assays <99th percentile.ResultsEight hundred and forty patients were studied of whom 177 (21%) had a TIMI score of 0. There were no MI, MACE or revascularization in the per protocol and intention-to-treat 2-h troponin groups (0%, 95% confidence interval (CI) 0% to 4.5% and 0%, 95% CI 0% to 3.8%, respectively). The negative predictive value (NPV) was 100% (95% CI 95.5% to 100%) and 100% (95% CI 96.2% to 100%), respectively.ConclusionsA 2-h accelerated rule-out process for ED chest pain patients using electrocardiography, a TIMI score of 0 and a contemporary sensitive troponin assay accurately identifies a group at very low risk of 30-day MI or MACE.

Risk stratification for prediction of adverse coronary events in emergency department chest pain patients with a machine learning score compared with the TIMI score

a Department of Emergency Medicine, Singapore General Hospital, Singapore b Centre for Quantitative Medicine, Duke-NUS Graduate Medical School, Singapore c SingHealth Emergency Medicine Residency Program, Singapore Health Services, Singapore d Department of Statistics and Applied Probability, National University of Singapore, Singapore e Division of Research, Singapore General Hospital, Singapore f Singapore Institute of Technology, Singapore g School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore h Health Services and Systems Research, Duke-NUS Graduate Medical School, Singapore

What is the 30-day rate of adverse cardiac events in chest pain patients with ED troponin I assays≤99th centile using a contemporary sensitive assay? An exploratory analysis

For nonhigh-risk patients who 'rule out' for acute coronary syndrome, Australasian guidelines recommend further testing to identify coronary artery disease. Testing is usually performed as an outpatient procedure. This recommendation has not changed with the advent of sensitive biomarker assays. We aimed to determine the 30-day rate of adverse cardiac events in emergency department (ED) chest pain patients without known coronary artery disease who had ED troponin I (TnI) assays≤99th centile using a contemporary troponin assay, stratified by the Heart Foundation (HF; Australia) risk group. This study is a substudy of a prospective observational study. Clinical and investigational data were collected. The primary outcome of interest was the proportion of patients with ED TnI assays≤99th centile who suffered a major adverse cardiac event (MACE; myocardial infarction, death, major arrhythmia) within 30 days, stratified by HF risk group. The secondary outcome was the rate of MACE or revascularization in non-HF high-risk patients. A total of 460 patients were studied. Among them, 388 had no TnI assay>99th centile. There was one MACE in this group [0.26%, 95% confidence interval (CI) 0.05-1.5%]: a non-ST segment elevation myocardial infarction in an HF high-risk patient. There were no MACEs among nonhigh-risk patients (0%, 95% CI 0-1.5%), and one patient had revascularization (0.4%; 95% CI 0.7-2.2%). Among ED patients presenting with suspected acute coronary syndrome, adverse cardiac events at 30 days are rare in nonhigh-risk patients with contemporary TnI assays<99th centile.

What decides the suspicion of acute coronary syndrome in acute chest pain patients?

BackgroundPhysicians assessing chest pain patients in the emergency department (ED) base the likelihood of acute coronary syndrome (ACS) mainly on ECG, symptom history and blood markers of myocardial injury. Among these, the ECG has been stated to be the most important diagnostic tool. We aimed to analyze the relative contributions of these three diagnostic modalities to the ED physicians’ evaluation of ACS likelihood in clinical practice.Methods1151 consecutive ED chest pain patients were prospectively included. The ED physician’s subjective assessment of the patient’s likelihood of ACS (obvious ACS, strong, vague or no suspicion of ACS), the symptoms and the ECG were recorded on a special form. The ED TnT value was retrieved from the medical records. Frequency tables and logistic regression models were used to evaluate the contributions of the diagnostic tests to the level of ACS suspicion.ResultsSymptoms determined whether the physician had any suspicion of ACS (odds ratio, OR 526 for symptoms typical compared to not suspicious of ACS) since neither ECG nor TnT contributed significantly (ORs not significantly different from 1) to this assessment. ACS was suspected in only one in ten patients with symptoms not suspicious of ACS. Symptoms were also more important (OR 620 for typical symptoms) than ECG (OR 31 for ischemic ECG) and TnT (OR 3.4 for a positive TnT) for the assessment of obvious ACS/strong suspicion versus vague/no suspicion. Of the patients with ST-elevation on ECG, 71% were considered to have an obvious ACS, as opposed to only 6% of those with symptoms typical of ACS and 10% of those with a positive TnT.ConclusionThe ED physicians used symptoms as the most important assessment tool and applied primarily the symptoms to determine the level of ACS suspicion and to rule out ACS. The ECG was primarily used to rule in ACS. The TnT level played a minor role for the assessment of ACS likelihood. Further studies regarding ACS prediction based on symptoms may help improve decision-making in ED patients with possible ACS.

Development and validation of a prediction rule for early discharge of low-risk emergency department patients with potential ischemic chest pain

Current guidelines emphasize that emergency department (ED) patients at low risk for potential ischemic chest pain cannot be discharged without extensive investigations or hospitalization to minimize the risk of missing acute coronary syndrome (ACS). We sought to derive and validate a prediction rule that permitted 20 to 30% of ED patients without ACS safely to be discharged within 2 hours without further provocative cardiac testing. This prospective cohort study enrolled 1,669 chest pain patients in two blocks in 2000-2003 (development cohort) and 2006 (validation cohort). The primary outcome was 30-day ACS diagnosis. A recursive partitioning model incorporated reliable and predictive cardiac risk factors, pain characteristics, electrocardiographic findings, and cardiac biomarker results. In the derivation cohort, 165 of 763 patients (21.6%) had a 30-day ACS diagnosis. The derived prediction rule was 100.0% sensitive and 18.6% specific. In the validation cohort, 119 of 906 patients (13.1%) had ACS, and the prediction rule was 99.2% sensitive (95% CI 95.4-100.0) and 23.4% specific (95% CI 20.6-26.5). Patients have a very low ACS risk if arrival and 2-hour troponin levels are normal, the initial electrocardiogram is nonischemic, there is no history of ACS or nitrate use, age is < 50 years, and defined pain characteristics are met. The validation of the rule was limited by the lack of consistency in data capture, incomplete follow-up, and lack of evaluation of the accuracy, comfort, and clinical sensibility of this clinical decision rule. The Vancouver Chest Pain Rule may identify a cohort of ED chest pain patients who can be safely discharged within 2 hours without provocative cardiac testing. Further validation across other centres with consistent application and comprehensive and uniform follow-up of all eligible and enrolled patients, in addition to measuring and reporting the accuracy of and comfort level with applying the rule and the clinical sensibility, should be completed prior to adoption and implementation.

Measuring Patient Tolerance for Future Adverse Events in Low-Risk Emergency Department Chest Pain Patients

We assess emergency department (ED) patients' risk thresholds for preferring admission versus discharge when presenting with chest pain and determine how the method of information presentation affects patients' choices. In this cross-sectional survey, we enrolled a convenience sample of lower-risk acute chest pain patients from an urban ED. We presented patients with a hypothetical value for the risk of adverse outcome that could be decreased by hospitalization and asked them to identify the risk threshold at which they preferred admission versus discharge. We randomized patients to a method of numeric presentation (natural frequency or percentage) and the initial risk presented (low or high) and followed each numeric assessment with an assessment based on visually depicted risks. We enrolled 246 patients and analyzed data on 234 with complete information. The geometric mean risk threshold with numeric presentation was 1 in 736 (1 in 233 with a percentage presentation; 1 in 2,425 with a natural frequency presentation) and 1 in 490 with a visual presentation. Fifty-nine percent of patients (137/234) chose the lowest or highest risk values offered. One hundred fourteen patients chose different thresholds for numeric and visual risk presentations. We observed strong anchoring effects; patients starting with the lowest risk chose a lower threshold than those starting with the highest risk possible and vice versa. Using an expected utility model to measure patients' risk thresholds does not seem to work, either to find a stable risk preference within individuals or in groups. Further work in measurement of patients' risk tolerance or methods of shared decisionmaking not dependent on assessment of risk tolerance is needed.

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

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. 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. 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 30days and 1year. Patients who do not meet study criteria or do not consent for randomization are offered entry into an observational registry. 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.