Clinical risk stratification in the emergency department predicts long-term cardiovascular outcomes in a population-based cohort presenting with acute chest pain: primary results of the Olmsted county chest pain study

Long-term cardiovascular risk prediction in the emergency department: a mixed-methods study protocol

INTRODUCTION

Cardiovascular disease (CVD) remains one of the leading causes of preventable death in Europe, therefore any opportunity to intervene and improve care should be maximised. Known CVD risk factors are routinely collected in the emergency department (ED), yet they are often not acted on. If the risk factors have prognostic value and a pathway can be created, then this would provide more holistic care for patients and reduce health system inefficiency.

METHODS AND ANALYSIS

In this mixed-methods study, we will use quantitative methods to investigate the prognostic characteristics of routinely collected data for long-term CVD outcomes, and qualitative methods to investigate how to use and implement this knowledge. The quantitative arm will use a database of approximately 21 000 chest pain patient episodes with a mean follow-up of 7.3 years. We will use Cox regression to evaluate the prognostic characteristics of routinely collected ED data for long-term CVD outcomes. We will also use a series of semi-structured interviews to co-design a prototype care pathway with stakeholders via thematic analysis. To enable the development of prototypes, themes will be structured into a logic model consisting of situation, inputs, outputs and mechanism.

ETHICS AND DISSEMINATION

This work has been approved by Research Ethics Committee (Wales REC7) and the Human Research Authority under reference 19/WA/0312 and 19/WA/0311. It has also been approved by the Confidentiality Advisory Group reference 19/CAG/0209. Dissent recorded in the NHS' opt-out scheme will be applied to the dataset by NHS Digital. This work will be disseminated through peer-review publication, conference presentation and a public dissemination strategy.

TRIAL REGISTRATION NUMBER

ISRCTN41008456.

PROTOCOL VERSION

V.1.0-7 June 2021.

Multimorbidity in Patients With Acute Coronary Syndrome Is Associated With Greater Mortality, Higher Readmission Rates, and Increased Length of Stay: A Systematic Review

OBJECTIVE

The aims of this systematic review were to determine the magnitude and impact of multimorbidity (≥2 chronic conditions) on mortality, length of stay, and rates of coronary intervention in patients with acute coronary syndrome (ACS) and to compare the prevalence of cardiovascular versus noncardiovascular multimorbidities.

METHODS

MEDLINE, PubMed, MedlinePlus, EMBASE, OVID, and CINAHL databases were searched for studies published between 2009 and 2019. Eight original studies enrolling patients with ACS and assessing cardiovascular and noncardiovascular comorbid conditions met the inclusion criteria. Study quality was evaluated using the Crowe Critical Appraisal Tool.

RESULTS

The most frequently examined cardiovascular multimorbidities included hypertension, diabetes, heart failure, atrial fibrillation, stroke/transient ischemic attack, coronary heart disease, and peripheral vascular disease; the most frequently examined noncardiovascular multimorbidities included cancer, anemia, chronic obstructive pulmonary disease, renal disease, liver disease, and depression. The prevalence of multimorbidity in the population with ACS is high (25%-95%). Patients with multimorbidities receive fewer evidence-based treatments, including coronary intervention and high-dose statins. Patients with multimorbidities experience higher in-hospital mortality (5%-13.9% vs 2.6%-6.1%), greater average length of stay (5-9 vs 3-4 days), and lower rates of revascularization (9%-14% vs 39%-42%) than nonmultimorbid patients. Women, despite being the minority in all sample populations, exhibited greater levels of multimorbidity than men.

CONCLUSIONS

Multimorbid patients with ACS are at a greater risk for worse outcomes than their nonmultimorbid counterparts. Lack of consistent measurement makes interpretation of the impact of multimorbidity challenging and emphasizes the need for more research on multimorbidity's effects on postdischarge healthcare utilization.

Artificial Intelligence to Assist in Exclusion of Coronary Atherosclerosis During CCTA Evaluation of Chest Pain in the Emergency Department: Preparing an Application for Real-world Use

Coronary computed tomography angiography (CCTA) evaluation of chest pain patients in an emergency department (ED) is considered appropriate. While a "negative" CCTA interpretation supports direct patient discharge from an ED, labor-intensive analyses are required, with accuracy in jeopardy from distractions. We describe the development of an artificial intelligence (AI) algorithm and workflow for assisting qualified interpreting physicians in CCTA screening for total absence of coronary atherosclerosis. The two-phase approach consisted of (1) phase 1-development and preliminary testing of an algorithm for vessel-centerline extraction classification in a balanced study population (n = 500 with 50% disease prevalence) derived by retrospective random case selection, and (2) phase 2-simulated clinical Trialing of developed algorithm on a per-case (entire coronary artery tree) basis in a more "real-world" study population (n = 100 with 28% disease prevalence) from an ED chest pain series. This allowed pre-deployment evaluation of the AI-based CCTA screening application which provides vessel-by-vessel graphic display of algorithm inference results integrated into a clinically capable viewer. Algorithm performance evaluation used area under the receiver operating characteristic curve (AUC-ROC); confusion matrices reflected ground truth vs AI determinations. The vessel-based algorithm demonstrated strong performance with AUC-ROC = 0.96. In both phase 1 and phase 2, independent of disease prevalence differences, negative predictive values at the case level were very high at 95%. The rate of completion of the algorithm workflow process (96% with inference results in 55-80 s) in phase 2 depended on adequate image quality. There is potential for this AI application to assist in CCTA interpretation to help extricate atherosclerosis from chest pain presentations.

Clinical outcomes for chest pain patients discharged home from emergency departments using high-sensitivity versus conventional cardiac troponin assays

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) assays enhance detection of lower circulating troponin concentrations, but the impact on outcomes in clinical practice is unclear. Our objective was to compare outcomes of chest pain patients discharged from emergency departments (EDs) using hs-cTn and conventional troponin (cTn) assays.

METHODS

We conducted an observational study of chest pain patients aged 40-105 years who presented to an ED from April 1, 2013, to March 31, 2017, and were discharged home. We compared 30-day and 1-year outcomes of EDs that used hs-cTn versus cTn assays. The primary outcome was a composite of all-cause death, myocardial infarction or unstable angina. Comparisons were conducted with (1) no adjustment; (2) adjustment for demographic, socioeconomic, and hospital characteristics; and (3) full clinical adjustment.

RESULTS

Among the 394,910 patients, 62,138 (15.7%) were evaluated at hs-cTn EDs and 332,772 (84.3%) were evaluated at cTn EDs. Patients discharged from hs-cTn EDs were less likely to have diabetes, hypertension, or prior heart disease. At 30 days, the unadjusted primary outcome rate was lower in hs-cTn EDs (0.9% vs 1.0%, P < .001). The 30-day hazard ratios for the primary outcome were 0.84 (95% CI 0.77-0.92) for no adjustment and 0.98 (95% CI 0.88-1.08) for full adjustment. Over 1 year, patients discharged from hs-cTn EDs had significantly fewer primary outcomes (3.7% vs 4.1%, P < .001) and lower hazard ratio (0.93; 95% CI 0.89-0.98) even after full adjustment.

CONCLUSIONS

Hs-cTn testing was associated with a significantly lower adjusted hazard of myocardial infarction, angina, and all-cause hospitalization at 1 year but not 30 days.

Implementation of an Early Discharge Protocol and Chest Pain Clinic for Low-Risk Chest Pain in the Emergency Department

BACKGROUND

Most of the patients presenting to emergency department with chest pain are at low risk of adverse events. Identifying high-risk patients can be challenging and resource intensive.

METHODS

We created a protocol to assist early discharge of low-risk adults with chest pain from emergency department. Also a chest pain clinic (CPC) was started for cardiology follow-up within 72 hours. In a retrospective cohort study, primary outcome of major adverse cardiac events (MACEs) of death, myocardial infarction, or revascularization was compared between CPC patients and those hospitalized for observation. In addition, rate of observation admissions and MACE were compared in the pre- and postintervention periods using piecewise regression and multiple logistic regression, respectively.

RESULTS

A total of 1422 patients were admitted for observation, and 290 were seen in CPC in the 1-year postintervention period. Thirty-day MACE was very low (0.7% in observation and 0.3% in CPC) postintervention. A total of 3637 patients were admitted for observation over the 2-year preintervention period. Thirty-day-adjusted MACE rate was not significantly different between pre- and postintervention periods (0.4% vs. 0.6%, P = 0.3), also monthly observation admissions did not change significantly; however, utilization of stress testing (57.2% vs. 41.0%, P < 0.001) and cardiac catheterization (2.3% vs. 1.6%, P = 0.036) was reduced.

CONCLUSION

Chest pain patients admitted for observation and risk stratification are at very low risk of 30-day MACE. An intervention based on a chest pain protocol and availability of early cardiology follow-up did not change the admission rate of these patients. This intervention was not associated with increased risk of adverse outcomes.

Effect of Acute Coronary Syndrome Probability on Diagnostic and Prognostic Performance of High-Sensitivity Cardiac Troponin

BACKGROUND

There is concern that high-sensitivity cardiac troponin (hs-cTn) may have low diagnostic accuracy in patients with low acute coronary syndrome (ACS) probability.

METHODS

We prospectively stratified patients presenting with acute chest discomfort to the emergency department (ED) into 3 groups according to their probability for ACS as assessed by the treating ED physician using a visual analog scale: ≤10%, 11% to 79%, and ≥80%, reviewing all information available at 90 min. hs-cTnT and hs-cTnI concentrations were determined in a blinded fashion. Two independent cardiologists adjudicated the final diagnosis.

RESULTS

Among 3828 patients eligible for analysis, 1189 patients had low (≤10%) probability for ACS. The incidence of non-ST-segment elevation myocardial infarction (NSTEMI) increased from 1.3% to 12.2% and 54.8% in patients with low, intermediate, and high ACS probability, respectively. The positive predictive value of hs-cTnT and hs-cTnI was low in patients with low ACS probability and increased with the incidence of NSTEMI, whereas the diagnostic accuracy of hs-cTnT and hs-cTnI for NSTEMI as quantified by the area under the curve (AUC) was very high and comparable among all 3 strata, e.g., AUC hs-cTnI, 0.96 (95% CI, 0.94–0.97); 0.87 (95% CI, 0.85–0.89); and 0.89 (95% CI, 0.87–0.92), respectively. Findings were validated using bootstrap analysis as an alternative methodology to define ACS probability. Similarly, higher hs-cTnT/I concentrations independently predicted all-cause mortality within 2 years (e.g., hs-cTnT hazard ratio, 1.39; 95% CI, 1.27–1.52), irrespective of ACS probability.

CONCLUSIONS

Diagnostic and prognostic accuracy and utility of hs-cTnT and hs-cTnI remain high in patients with acute chest discomfort and low ACS probability.

ClinicalTrials.gov Identifier: NCT00470587.

An alternative tool for triaging patients with possible acute coronary symptoms before admission to a chest pain unit

OBJECTIVE

This study aimed to develop a triage tool to more effectively triage possible ACS patients presenting to the emergency department (ED) before admission to a protocol-driven chest pain unit (CPU).

METHODS

Seven hundred ninety-three clinical cases, randomly selected from 7962 possible ACS cases, were used to develop and test an ACS triage model using cluster analysis and stepwise logistic regression.

RESULTS

The ACS triage model, logit (suspected ACS patient)=-5.283+1.894×chest pain+1.612×age+1.222×male+0.958×proximal radiation pain+0.962×shock+0.519×acute heart failure, with a threshold value set at 2.5, was developed to triage patients. Compared to four existing methods, the chest-pain strategy, the Zarich's strategy, the flowchart, and the heart broken index (HBI), the ACS triage model had better performance.

CONCLUSION

This study developed an ACS triage model for triaging possible ACS patients. The model could be used as a rapid tool in EDs to reduce the workloads of ED nurses and physicians in relation to admissions to the CPU.

Acute coronary syndrome risk prediction of rapid emergency medicine scoring system in acute chest pain. An observational study of patients presenting with chest pain in the emergency department in Central Saudi Arabia

OBJECTIVES

To assess the diagnostic validity of the rapid emergency medical score (REMS) for the risk stratification of acute coronary syndrome (ACS) from non-cardiogenic chest pain. Methods: An observational cross-sectional study was carried out among patients presenting with chest pain to the Emergency Department of Prince Sultan Military Medical City, Riyadh, Kingdom of Saudi Arabia, for 6 months from January to June 2016. All patients, included through non-probability convenience sampling, were assessed using standard protocols for the physiological parameters of the REMS, and ACS was confirmed through electrocardiography, cardiac enzyme testing, and angiography (if needed). Data were analyzed using Statistical Package for Social Sciences software version 15 (SPSS Inc, Chicago, IL, USA). The validity of REMS was determined using a cutoff value of 17. Results: In total, 176 (70.4%) of patients were men with a mean age of 49±8.5 years. The mean REM score of the patients was 9.3±4.5, and a sensitivity of 81.6%, specificity of 90.05%, positive predictive value of 66.67%, and a negative predictive value of 95.26% were obtained. Conclusion: Rapid emergency medical score is a simple and fairly valid tool that may be used for diagnosis of ACS with limited resources in emergency medicine.

The Value of Continuous ST-Segment Monitoring in the Emergency Department

Practice standards for electrocardiographic monitoring recommend continuous ST-segment monitoring (C-STM) in patients presenting to the emergency department (ED) with signs and/or symptoms of acute coronary syndrome (ACS), but few studies have evaluated its use in the ED. We compared time to diagnosis and 30-day adverse events before and after implementation of C-STM. We also evaluated the diagnostic accuracy of C-STM in detecting ischemia and infarction. We prospectively studied 163 adults (preintervention: n = 78; intervention: n = 85) in a single ED and stratified them into low (n = 51), intermediate (n = 100), or high (n = 12) risk using History, ECG, Age, Risk factors, and Troponin (HEART) scores. The principal investigator monitored participants, activating C-STM on bedside monitors in the intervention phase. We used likelihood ratios (LRs) as the measure of diagnostic accuracy. Overall, 9% of participants were diagnosed with ACS. Median time to diagnosis did not differ before and after implementation of C-STM (5.55 vs. 5.98 hr; p = 0.43). In risk-stratified analyses, no significant pre-/postdifference in time to diagnosis was found in low-, intermediate-, or high-risk participants. There was no difference in the rate of 30-day adverse events before versus after C-STM implementation (11.5% vs. 10.6%; p = 0.85). The +LR and -LR of C-STM for ischemia were 24.0 (95% confidence interval [CI]: 1.4, 412.0) and 0.3 (95% CI: 0.02, 2.9), respectively, and for infarction were 13.7 (95% CI: 1.7, 112.3) and 0.7 (95% CI: 0.3, 1.5), respectively. Use of C-STM did not provide added diagnostic benefit for patients with signs and/or symptoms of myocardial ischemia in the ED.

Recent Scientific Evidence and Technical Developments in Cardiovascular Computed Tomography

In recent years, coronary computed tomography angiography has become an increasingly safe and noninvasive modality for the evaluation of the anatomical structure of the coronary artery tree with diagnostic benefits especially in patients with a low-to-intermediate pretest probability of disease. Currently, increasing evidence from large randomized diagnostic trials is accumulating on the diagnostic impact of computed tomography angiography for the management of patients with acute and stable chest pain syndrome. At the same time, technical advances have substantially reduced adverse effects and limiting factors, such as radiation exposure, the amount of iodinated contrast agent, and scanning time, rendering the technique appropriate for broader clinical applications. In this work, we review the latest developments in computed tomography technology and describe the scientific evidence on the use of cardiac computed tomography angiography to evaluate patients with acute and stable chest pain syndrome.

Management of acute chest pain: A major role for coronary CT angiography

Most patients presenting with acute chest pain (ACP) at the emergency unit do not have any marked electrocardiogram abnormalities or known history of heart disease. Identifying the few patients who have, or will actually develop acute coronary syndrome in this group that is considered to be at low risk, is an actual clinical challenge for emergency department physicians. In these patients, the goal of complementary non-invasive morphological or functional imaging tests is to exclude heart disease. The diagnostic values of coronary CT angiography include a sensitivity of 96% and a negative likelihood ratio of 0.09, which are highly contributory to the diagnosis, and the integration of this imaging test into a decision tree algorithm appears to be the least expensive strategy with the best cost/effective ratio. Coronary CT angiography is indicated in the presence of ACP associated with an inconclusive electrocardiogram, in the absence of any other obvious diagnoses, when the ultrasensitive troponin assay is negative or the dynamic changes are modest, slow and/or inconclusive. Ideally, coronary CT angiography should be performed within 3 to 48hours after the initial consultation.

Nuclear scan strategy and outcomes in chest pain patients value of stress testing with dipyridamole or adenosine

Objective:

To update the prognostic value of scan strategy with pharmacological stress agent in chest pain (CP) patients presenting with normal electrocardiography (ECG) and troponin.

Methods:

Two consecutive nonrandomized series of patients with CP and negative first-line workup inclusive of serial ECG, serial troponin, and echocardiography underwent myocardial perfusion imaging single photon emission computed tomography (SPECT) in the emergency department. Of 170 patients enrolled, 52 patients underwent dipyridamole-SPECT and 118 adenosine-SPECT. Patients with perfusion defects underwent angiography, whereas the remaining patients were discharged and followed-up. Primary endpoint was the composite of nonfatal myocardial infarction, unstable angina, revascularization, and cardiovascular death at follow-up or the presence of coronary stenosis > 50% at angiography.

Results:

At multivariate analysis, the presence of perfusion defects or hypertension was independent predictor of the primary endpoint. Sensitivity and negative predictive value were higher in patients subjected to adenosine-SPECT (95% and 99%, respectively) versus dipyridamole-SPECT (56% and 89%; yield 70% and 11%, respectively; P < 0.03). Of note, sensitivity, negative, and positive predictive values were high in patients with hypertension (100%, 93%, and 60%, respectively) or nonischemic echocardiography alterations (100%, 100%, and 100%, respectively).

Conclusions:

In CP patients, presenting with normal ECG and troponin, adenosine-SPECT adds incremental prognostic values to dipyridamole-SPECT. Costly scan strategy is more appropriate and avoids unnecessary angiograms in patients with hypertension or nonischemic echocardiography alterations.

Evaluation and outcomes of patients admitted to a tertiary medical assessment unit with acute chest pain of possible coronary origin

OBJECTIVES

The study aims to (i) profile clinical characteristics, risk estimates of acute coronary syndrome (ACS), use and yield of non-invasive cardiac testing, discharge diagnosis and 30-day outcomes among patients admitted with acute chest pain of possible coronary origin; and (ii) construct a risk stratification algorithm that informs management decisions.

METHODS

This is a retrospective cohort study of 130 consecutive patients admitted to a tertiary hospital medical assessment unit between 24 January and 22 March 2012. Estimates of ACS risk were based on Australian guidelines and Thrombolysis in Myocardial Infarction (TIMI) scores.

RESULTS

Patients were of mean age 61 years, 45% had known coronary artery disease (CAD), 58% presented with typical ischaemic pain, 82% had intermediate to high ACS risk and 61% underwent testing. Myocardial ischaemia was cardiologist-confirmed discharge diagnosis in 29% of patients, and was associated with known CAD, typical pain, multiple risk factors and high TIMI risk scores (P < 0.001 for all associations). Of 98 non-invasive investigations, 9% (95% CI, 5-17%) were positive for myocardial ischaemia. Major adverse event rate at 30 days was 0.8% (95% CI, <0.1-6%). An algorithm was constructed that integrates known CAD, ACS risk and TIMI scores in identifying low-risk patients capable of rapid discharge from EDs without further investigation, and classifying the remainder into risk groups that informs choice of investigations and need for telemetry.

CONCLUSIONS

In patients with indeterminate chest pain, clinical features and risk scores identify most with myocardial ischaemia. An algorithm is presented that might inform triaging, early discharge, choice of testing and need for telemetry.

Biomarkers after risk stratification in acute chest pain (from the BRIC Study)

Current models incompletely risk-stratify patients with acute chest pain. In this study, N-terminal pro-B-type natriuretic peptide and cystatin C were incorporated into a contemporary chest pain triage algorithm in a clinically stratified population to improve acute coronary syndrome discrimination. Adult patients with chest pain presenting without myocardial infarction (n = 382) were prospectively enrolled from 2008 to 2009. After clinical risk stratification, N-terminal pro-B-type natriuretic peptide and cystatin C were measured and standard care was performed. The primary end point was the result of a clinical stress test. The secondary end point was any major adverse cardiac event at 6 months. Associations were determined through multivariate stratified analyses. In the low-risk group, 76 of 78 patients with normal levels of the 2 biomarkers had normal stress test results (negative predictive value 97%). Normal biomarkers predicted normal stress test results with an odds ratio of 10.56 (p = 0.006). In contrast, 26 of 33 intermediate-risk patients with normal levels of the 2 biomarkers had normal stress test results (negative predictive value 79%). Biomarkers and stress test results were not associated in the intermediate-risk group (odds ratio 2.48, p = 0.09). There were 42 major adverse cardiac events in the overall cohort. No major adverse cardiac events occurred at 6 months in the low-risk subgroup that underwent stress testing. In conclusion, N-terminal pro-B-type natriuretic peptide and cystatin C levels predict the results of stress tests in low-risk patients with chest pain but should not be substituted for stress testing in intermediate-risk patients. There is potential for their use in the early discharge of low-risk patients after clinical risk stratification.

Predictive value of a 4-hour accelerated diagnostic protocol in patients with suspected ischemic chest pain presenting to an emergency department

OBJECTIVES

Currently recommended risk stratification protocols for suspected ischemic chest pain in the emergency department (ED) includes point-of-care availability of exercise treadmill/nuclear tests or CT coronary angiograms. These tests are not widely available for most of the ED's. This study aims to prospectively validate the safety of a predefined 4-hour accelerated diagnostic protocol (ADP) using chest pain, ECG, and troponin T among suspected ischemic chest pain patients presenting to an ED of a tertiary care hospital in Oman.

METHODS

One hundred and thirty-two patients aged over 18 years with suspected ischemic chest pain presenting within 12 hours of onset along with normal or non-diagnostic first ECG and negative first troponin T (<0.010 μg/l) were recruited from September 2008 to February 2009. Low-probability acute coronary syndrome (ACS) patients at 4-hours defined as absent chest pain and negative ECG or troponin tests were discharged home and observed for 30-days for major adverse cardiac events (MACE) (Group I: negative ADP). High-probability ACS patients at 4-hours were defined by recurrent or persistent chest pain, positive ECG or troponin tests and were admitted and observed for in-hospital MACE (Group II: positive ADP).

RESULTS

One hundred and thirty-two patients were recruited and 110 patients completed the study. The overall 30-day MACE in this cohort was 15% with a mortality of less than 1%. 30-days MACE occurred in 8/95 of group I patients (8.4%) and 9/15 of the in-hospital MACE patients in group II. The ADP had a sensitivity of 52% (95% CI: 0.28-0.76), specificity of 93% (0.85-0.97), a negative predictive value of 91% (0.83-0.96), a positive predictive value of 60% (0.32-0.82), negative likelihood ratio of 0.5 (0.30-0.83) and a positive likelihood ratio of 8.2 (3.3-20) in predicting MACE.

CONCLUSION

A 4-hour ADP using chest pain, ECG, and troponin T had high specificity and negative predictive value in predicting 30-day MACE among low probability ACS patients discharged from ED. However, 30-day MACE in ADP negative patients was relatively high in contrast to guideline recommendations. Hence, there is a need to establish ED chest pain unit and adopt new protocols especially adding a point-of-care exercise treadmill test in the ED.

Systolic blood pressure at Emergency Department presentation and 1-year mortality in acute chest pain patients

BACKGROUND

High blood pressure at rest has been an established risk factor for cardiovascular disease. However the relationship between Systolic Blood Pressure (SBP) and 1-year-mortality among acute chest pain patients presenting to Emergency Department (ED); and effects of preexisting renal insufficiency, hemodynamic stress - as quantified by Brain Natriuretic Peptide (BNP) and chest pain duration, on this relationship is unknown.

METHODS

Data was used from APACE (Advantageous Predictors of Acute Coronary Syndrome Evaluation), a prospective observational multicenter study of 1240 ED chest pain patients. SBP at presentation was categorized into quartiles: Q1≤127mmHg; Q2 128-142mmHg; Q3 143-160mmHg; Q4≥161mmHg.

RESULTS

60 deaths occurred during 1-year. One-year-mortality-rate showed lower Hazard Ratios for Q2, Q3 and Q4 vs Q1 (HR [95% CI]; 0.39 (0.19-0.78), 0.34 (0.17-0.70), 0.35 (0.17-0.72); p<0.01 respectively). Cox model adjusted for various demographic and treatment variables showed that participants in Q3 and Q4 had better prognoses than Q1. Patients showed progressively better prognosis from Q2 through Q4 vs Q1 only in patients who presented to ED with for more than 12h of chest pain duration. Patients with renal insufficiency had lower SBP at presentation than others (p=0.001). There was no association between the outcome and interaction variable of SBP quartiles and BNP (p=0.27).

CONCLUSION

Acute chest pain patients presenting to ED exhibit an inverse association between SBP at presentation and 1-year-mortality; a relationship which appears stronger in those who present with chest pain of greater than 12h duration.

Acute coronary syndrome clinical presentations and diagnostic approaches in the emergency department

This article discusses clinical presentations and diagnostic approaches to acute coronary syndrome in the emergency department.

Testing of low-risk patients presenting to the emergency department with chest pain: a scientific statement from the American Heart Association

The management of low-risk patients presenting to emergency departments is a common and challenging clinical problem entailing 8 million emergency department visits annually. Although a majority of these patients do not have a life-threatening condition, the clinician must distinguish between those who require urgent treatment of a serious problem and those with more benign entities who do not require admission. Inadvertent discharge of patients with acute coronary syndrome from the emergency department is associated with increased mortality and liability, whereas inappropriate admission of patients without serious disease is neither indicated nor cost-effective. Clinical judgment and basic clinical tools (history, physical examination, and electrocardiogram) remain primary in meeting this challenge and affording early identification of low-risk patients with chest pain. Additionally, established and newer diagnostic methods have extended clinicians' diagnostic capacity in this setting. Low-risk patients presenting with chest pain are increasingly managed in chest pain units in which accelerated diagnostic protocols are performed, comprising serial electrocardiograms and cardiac injury markers to exclude acute coronary syndrome. Patients with negative findings usually complete the accelerated diagnostic protocol with a confirmatory test to exclude ischemia. This is typically an exercise treadmill test or a cardiac imaging study if the exercise treadmill test is not applicable. Rest myocardial perfusion imaging has assumed an important role in this setting. Computed tomography coronary angiography has also shown promise in this setting. A negative accelerated diagnostic protocol evaluation allows discharge, whereas patients with positive findings are admitted. This approach has been found to be safe, accurate, and cost-effective in low-risk patients presenting with chest pain.