HEART Score Recalibration Using Higher Sensitivity Troponin T.

STUDY OBJECTIVE: We examined the diagnostic performance of a recalibrated History, Electrocardiogram, Age, Risk factors, Troponin (HEART), and Thrombolysis in Myocardial Infarction (TIMI) score in patients with suspected acute cardiac syndrome (ACS). Recalibration of troponin thresholds was performed, including shifting from the 99th percentile to the limit of detection (LOD) or to the limit of quantification (LOQ) We compared the discharge potential and safety of the recalibrated composite scores using a single presentation high-sensitivity cardiac troponin (hs-cTn) T to the conventional scores and with a LOD/LOQ troponin strategy alone. METHODS: We undertook a 2-center prospective cohort study in the United Kingdom (UK) (2018) (Clinicaltrials.gov NCT03619733) to specifically assess recalibrated risk scores (shifting the troponin subset scoring from 99th percentile to LOD [UK]) and combined the results of this with secondary analyses of 2 prospective cohort studies in the UK (2011) and the United States (2018, using LOQ rather than LOD). The primary outcome was major adverse cardiovascular events (MACE), defined as adjudicated type 1 myocardial infarction (MI), urgent coronary revascularization, and all-cause death, at 30 days. We evaluated the original scores using hs-cTn below the 99th percentile and recalibrated scores using hs-cTn

Improved prehospital triage for acute cardiac care: results from HART-c, a multicentre prospective study.

BACKGROUND: Cardiac symptoms are one of the most prevalent reasons for emergency department visits. However, over 80% of patients with such symptoms are sent home after acute cardiovascular disease has been ruled out. OBJECTIVE: The Hollands-Midden Acute Regional Triage-cardiology (HART-c) study aimed to investigate whether a novel prehospital triage method, combining prehospital and hospital data with expert consultation, could increase the number of patients who could safely stay at home after emergency medical service (EMS) consultation. METHODS: The triage method combined prehospital EMS data, such as electrocardiographic and vital parameters in real time, and data from regional hospitals (including previous medical records and admission capacity) with expert consultation. During the 6­month intervention and control periods 1536 and 1376 patients, respectively, were consulted by the EMS. The primary endpoint was the percentage change of patients who could stay at home after EMS consultation. RESULTS: The novel triage method led to a significant increase in patients who could safely stay at home, 11.8% in the intervention group versus 5.9% in the control group: odds ratio 2.31 (95% confidence interval (CI) 1.74-3.05). Of 181 patients staying at home, only 1 (< 1%) was later diagnosed with ACS; no patients died. Furthermore the number of interhospital transfers decreased: relative risk 0.81 (95% CI 0.67-0.97). CONCLUSION: The HART­c triage method led to a significant decrease in interhospital transfers and an increase in patients with cardiac symptoms who could safely stay at home. The presented method thereby reduced overcrowding and, if implemented throughout the country and for other medical specialties, could potentially reduce the number of cardiac and non-cardiac hospital visits even further.

Effect of Using the HEART Score in Patients With Chest Pain in the Emergency Department: A Stepped-Wedge, Cluster Randomized Trial.

BACKGROUND: The HEART (History, Electrocardiogram, Age, Risk factors, and initial Troponin) score is an easy-to-apply instrument to stratify patients with chest pain according to their short-term risk for major adverse cardiac events (MACEs), but its effect on daily practice is unknown. OBJECTIVE: To measure the effect of use of the HEART score on patient outcomes and use of health care resources. DESIGN: Stepped-wedge, cluster randomized trial. (ClinicalTrials.gov: NCT01756846). SETTING: Emergency departments in 9 Dutch hospitals. PATIENTS: Unselected patients with chest pain presenting at emergency departments in 2013 and 2014. INTERVENTION: All hospitals started with usual care. Every 6 weeks, 1 hospital was randomly assigned to switch to "HEART care," during which physicians calculated the HEART score to guide patient management. MEASUREMENTS: For safety, a noninferiority margin of a 3.0% absolute increase in MACEs within 6 weeks was set. Other outcomes included use of health care resources, quality of life, and cost-effectiveness. RESULTS: A total of 3648 patients were included (1827 receiving usual care and 1821 receiving HEART care). Six-week incidence of MACEs during HEART care was 1.3% lower than during usual care (upper limit of the 1-sided 95% CI, 2.1% [within the noninferiority margin of 3.0%]). In low-risk patients, incidence of MACEs was 2.0% (95% CI, 1.2% to 3.3%). No statistically significant differences in early discharge, readmissions, recurrent emergency department visits, outpatient visits, or visits to general practitioners were observed. LIMITATION: Physicians were hesitant to refrain from admission and diagnostic tests in patients classified as low risk by the HEART score. CONCLUSION: Using the HEART score during initial assessment of patients with chest pain is safe, but the effect on health care resources is limited, possibly due to nonadherence to management recommendations. PRIMARY FUNDING SOURCE: Netherlands Organisation for Health Research and Development.

Low-dose single acquisition rest (99m)Tc/stress (201)Tl myocardial perfusion SPECT protocol: phantom studies and clinical validation.

PURPOSE: We developed and tested a single acquisition rest (99m)Tc-sestamibi/stress (201)Tl dual isotope protocol (SDI) with the intention of improving the clinical workflow and patient comfort of myocardial perfusion single photon emission computed tomography (SPECT). METHODS: The technical feasibility of SDI was evaluated by a series of anthropomorphic phantom studies on a standard SPECT camera. The attenuation map was created by a moving transmission line source. Iterative reconstruction including attenuation correction, resolution recovery and Monte Carlo simulation of scatter was used for simultaneous reconstruction of dual tracer distribution. For clinical evaluation, patient studies were compared to stress (99m)Tc and rest (99m)Tc reference images acquired in a 2-day protocol. Clinical follow-up examinations like coronary angiography (CAG) and fractional flow reserve (FFR) were included in the assessment if available. RESULTS: Phantom studies demonstrated the technical feasibility of SDI. Artificial lesions inserted in the phantom mimicking ischaemia could be clearly identified. In 51/53 patients, the image quality was adequate for clinical evaluation. For the remaining two obese patients with body mass index > 32 the injected (201)Tl dose of 74 MBq was insufficient for clinical assessment. In answer to this the (201)Tl dose was adapted for obese patients in the rest of the study. In 31 patients, SDI and (99m)Tc reference images resulted in equivalent clinical assessment. Significant differences were found in 20 patients. In 18 of these 20 patients additional examinations were available. In 15 patients the diagnosis based on the SDI images was confirmed by the results of CAG or FFR. In these patients the SDI images were more accurate than the (99m)Tc reference study. In three patients minor ischaemic lesions were detected by SDI but were not confirmed by CAG. In one of these cases this was probably caused by pronounced apical thinning. For two patients no relevant clinical follow-up information was available for evaluation. CONCLUSION: The proposed SDI protocol has the potential to improve clinical workflow and patient comfort and suggests improved accuracy as demonstrated in the clinical feasibility study.

The value of clinical and laboratory diagnostics for chest pain patients at the emergency department.

BACKGROUND: The focus during the diagnostic process for patients with acute chest pain is to discriminate patients who can be safely discharged from those who are at risk for an acute coronary syndrome (ACS). In this study the diagnostic value of the clinical examination is compared with laboratory testing of troponin. METHODS: This study included 710 chest pain patients who presented at the ED of two hospitals in the Netherlands. Clinical examination and laboratory testing were combined in the recently developed HEART-score. The diagnostic values of clinical presentation, troponin and the HEART-score for a major adverse coronary event (MACE) and an ACS within 6 weeks were assessed. Furthermore, the improvement of HEART with the second troponin measurement after 6 h was assessed using the net reclassification improvement (NRI). RESULTS: The use of HEART (AUCMACE: 0.77; AUCACS: 0.82) obtains a higher diagnostic value than troponin (AUCMACE: 0.72; AUCACS: 0.74) or clinical evaluation (AUCMACE: 0.69; AUCACS: 0.74). Statistical significant different AUCs were obtained when HEART is compared to troponin or clinical evaluation (p<0.01). The use of the second troponin test (after 6 h of admission) within HEART resulted in an improvement of 8.0%. CONCLUSIONS: The HEART-score combines clinical evaluation and results from laboratory testing, which should be used together, to discriminate patients at risk of a cardiac event from patients who can be safely discharged. In addition, it is shown that a second troponin measurement slightly improves the discriminative ability of the HEART-score.

Consensus paper on the assessment of adult patients with traumatic brain injury with Glasgow Coma Scale 13-15 at the emergency department: A multidisciplinary overview.

Traumatic brain injury (TBI) is a common reason for presenting to emergency departments (EDs). The assessment of these patients is frequently hampered by various confounders, and diagnostics is still often based on nonspecific clinical signs. Throughout Europe, there is wide variation in clinical practices, including the follow-up of those discharged from the ED. The objective is to present a practical recommendation for the assessment of adult patients with an acute TBI, focusing on milder cases not requiring in-hospital care. The aim is to advise on and harmonize practices for European settings. A multiprofessional expert panel, giving consensus recommendations based on recent scientific literature and clinical practices, is employed. The focus is on patients with a preserved consciousness (Glasgow Coma Scale 13-15) not requiring in-hospital care after ED assessment. The main results of this paper contain practical, clinically usable recommendations for acute clinical assessment, decision-making on acute head computerized tomography (CT), use of biomarkers, discharge options, and needs for follow-up, as well as a discussion of the main features and risk factors for prolonged recovery. In conclusion, this consensus paper provides a practical stepwise approach for the clinical assessment of patients with an acute TBI at the ED. Recommendations are given for the performance of acute head CT, use of brain biomarkers and disposition after ED care including careful patient information and organization of follow-up for those discharged.

Assessment of the Diagnostic Accuracy and Reliability of the HEART Score Calculated by Ambulance Nurses Versus Emergency Physicians.

Chest pain is a common complaint for consultation of emergency medical services worldwide. Currently, ambulance nurses (AN) base their decision to transport a patient to the hospital on their own professional experience. The HEART score could improve prehospital risk stratification and patient treatment. The aim of this study is to investigate the interrater reliability and predictive accuracy of the HEART score between AN and emergency physicians (EP). A retrospective analysis on data of 569 patients 18 years and older included in two prehospital HEART score studies. The endpoints are interrater reliability (intraclass correlation [ICC]) and predictive accuracy for major adverse cardiac events within 30 days of the HEART score calculated by AN versus EP. Predictive accuracy is sensitivity, specificity, positive predicted value (PPV) and negative predicted value (NPV). Interrater reliability was good for total HEART score (ICC 0.78; 95% CI 0.75-0.81). However, focusing on the decision to transport a patient, the ICC dropped to 0.62 (95% CI 0.62-0.70). History and Risk factors caused the most variability. Predictive accuracy of HEART differed between AN and EP. The HEART score calculated by AN was sensitivity 91%, specificity 38%, PPV 26%, and NPV 95%. The HEART score calculated by EP was sensitivity 98%, specificity 32%, PPV -26%, and NPV 99%. With a cut-off value of 0-2 for a low HEART score, predictive accuracy significantly improved for the HEART score calculated by AN: sensitivity 98%, specificity 18%, PPV 22%, and NPV 98%. Our study shows a moderate interrater reliability and lower predictive accuracy of a HEART score calculated by AN versus EP. AN underestimate the risk of patients with acute chest pain, with the largest discrepancies in the elements History and Risk factors. Reconsidering the cut-off values of the low-risk HEART category, as well as a carefully developed training program, will possibly lead to a higher interrater reliability of the HEART score and higher predictive accuracy used by AN.

Emergency Department Risk Factors for Post-Concussion Syndrome After Mild Traumatic Brain Injury: A Systematic Review.

Approximately 16% of patients with mild traumatic brain injury (mTBI) develop a post-concussion syndrome (PCS) with persistent physical, neurological, and behavioral complaints. PCS has a great impact on a patient's quality of life, often decreases the ability to return to work, and henceforth has a great economic impact. Recent studies suggest that early treatment can greatly improve prognosis and prevent long-term effects in these patients. However, early recognition of patients at high risk of PCS remains difficult. The objective of this systematic review is to assess risk factors associated with the development of PCS, primarily aimed at the group of non-hospitalized patients who were seen with mTBI at the emergency department (ED). We searched PubMed/MEDLINE, Cochrane Library and EMBASE on September 23, 2022, for prospective studies that assessed the risk factors for the development of PCS. Exclusion criteria were: retrospective studies; > 20% computed tomography (CT) abnormalities, <18 years of age, follow-up <4 weeks, severe trauma, and study population <100 patients. The search strategy identified 1628 articles, of which 17 studies met eligibility criteria. Risk factors found in this systematic review are pre-existing psychiatric history, headache at the ED, neurological symptoms at the ED, female sex, CT abnormalities, pre-existent sleeping problems, and neck pain at the ED. This systematic review identified seven risk factors for development of PCS in patients with mTBI. Future research should assess if implementation of these risk factors into a risk stratification tool will assist the emergency physician in the identification of patients at high risk of PCS.

The impact of the HEART risk score in the early assessment of patients with acute chest pain: design of a stepped wedge, cluster randomised trial.

BACKGROUND: Chest pain remains a diagnostic challenge: physicians do not want to miss an acute coronary syndrome (ACS), but, they also wish to avoid unnecessary additional diagnostic procedures. In approximately 75% of the patients presenting with chest pain at the emergency department (ED) there is no underlying cardiac cause. Therefore, diagnostic strategies focus on identifying patients in whom an ACS can be safely ruled out based on findings from history, physical examination and early cardiac marker measurement. The HEART score, a clinical prediction rule, was developed to provide the clinician with a simple, early and reliable predictor of cardiac risk. We set out to quantify the impact of the use of the HEART score in daily practice on patient outcomes and costs. METHODS/DESIGN: We designed a prospective, multi-centre, stepped wedge, cluster randomised trial. Our aim is to include a total of 6600 unselected chest pain patients presenting at the ED in 10 Dutch hospitals during an 11-month period. All clusters (i.e. hospitals) start with a period of 'usual care' and are randomised in their timing when to switch to 'intervention care'. The latter involves the calculation of the HEART score in each patient to guide clinical decision; notably reassurance and discharge of patients with low scores and intensive monitoring and early intervention in patients with high HEART scores. Primary outcome is occurrence of major adverse cardiac events (MACE), including acute myocardial infarction, revascularisation or death within 6 weeks after presentation. Secondary outcomes include occurrence of MACE in low-risk patients, quality of life, use of health care resources and costs. DISCUSSION: Stepped wedge designs are increasingly used to evaluate the real-life effectiveness of non-pharmacological interventions because of the following potential advantages: (a) each hospital has both a usual care and an intervention period, therefore, outcomes can be compared within and across hospitals; (b) each hospital will have an intervention period which enhances participation in case of a promising intervention; (c) all hospitals generate data about potential implementation problems. This large impact trial will generate evidence whether the anticipated benefits (in terms of safety and cost-effectiveness) of using the HEART score will indeed be achieved in real-life clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov 80-82310-97-12154.

Management of major bleeding for anticoagulated patients in the Emergency Department: an European experts consensus statement.

An increasing number of patients presenting to the emergency department (ED) with life-threatening bleeding are using oral anticoagulants, such as warfarin, Factor IIa and Factor Xa inhibitors. Achieving rapid and controlled haemostasis is critically important to save the patient's life. This multidisciplinary consensus paper provides a systematic and pragmatic approach to the management of anticoagulated patients with severe bleeding at the ED. Repletion and reversal management of the specific anticoagulants is described in detail. For patients on vitamin K antagonists, the administration of vitamin K and repletion of clotting factors with four-factor prothrombin complex concentrate provides real-time ability to stop the bleeding. For patients using a direct oral anticoagulant, specific antidotes are necessary to reverse the anticoagulative effect. For patients receiving the thrombin inhibitor dabigatran, treatment with idarucizamab has been demonstrated to reverse the hypocoagulable state. For patients receiving a factor Xa inhibitor (apixaban or rivaroxaban), andexanet alfa is the indicated antidote in patients with major bleeding. Lastly, specific treatment strategies are discussed in patients using anticoagulants with major traumatic bleeding, intracranial haemorrhage or gastrointestinal bleeding.

Management of patients suspected for non-ST elevation-acute coronary syndrome in the prehospital phase.

The management of patients with suspected acute coronary syndrome, especially in prehospital settings, is challenging. This Special Report focuses on studies in emergency medical services concerning chest pain patients' triage and risk stratification. In addition, it emphasizes advancements in point-of-care cardiac troponin testing. These developments are compared with in-hospital guidelines, proposing an initial framework for a new acute care pathway. This pathway integrates a risk stratification tool with high-sensitivity cardiac troponin testing, aiming to deliver optimal care and collaboration within the acute care chain. It has the potential to contribute to a significant reduction in hospital referrals, reduce observation time and overcrowding at emergency departments and hospital admissions.

Prehospital triage of patients with acute cardiac complaints: study protocol of HART-c, a multicentre prospective study.

INTRODUCTION: Emergency department (ED) overcrowding is a major healthcare problem associated with worse patient outcomes and increased costs. Attempts to reduce ED overcrowding of patients with cardiac complaints have so far focused on in-hospital triage and rapid risk stratification of patients with chest pain at the ED. The Hollands-Midden Acute Regional Triage-Cardiology (HART-c) study aimed to assess the amount of patients left at home in usual ambulance care as compared with the new prehospital triage method. This method combines paramedic assessment and expert cardiologist consultation using live monitoring, hospital data and real-time admission capacity. METHODS AND ANALYSIS: Patients visited by the emergency medical services (EMS) for cardiac complaints are included. EMS consultation consists of medical history, physical examination and vital signs, and ECG measurements. All data are transferred to a newly developed platform for the triage cardiologist. Prehospital data, in-hospital medical records and real-time admission capacity are evaluated. Then a shared decision is made whether admission is necessary and, if so, which hospital is most appropriate. To evaluate safety, all patients left at home and their general practitioners (GPs) are contacted for 30-day adverse events. ETHICS AND DISSEMINATION: The study is approved by the LUMC's Medical Ethics Committee. Patients are asked for consent for contacting their GPs. The main results of this trial will be disseminated in one paper. DISCUSSION: The HART-c study evaluates the efficacy and feasibility of a prehospital triage method that combines prehospital patient assessment and direct consultation of a cardiologist who has access to live-monitored data, hospital data and real-time hospital admission capacity. We expect this triage method to substantially reduce unnecessary ED visits.

The interobserver agreement of the HEART-score, a multicentre prospective study.

BACKGROUND AND IMPORTANCE: Chest pain is one of the most common presentations to the emergency department (ED). The HEART-score is used to assess the 30-day risk of developing a major adverse cardiac event (MACE). The HEART-score enables clinicians to classify patients in low, intermediate, or high-risk groups though little is known as to whether this can be done reliably and reproducibly in a prehospital setting. OBJECTIVE: The aim of this study was to compare the interobserver agreement of the HEART-score between ambulance nurses and ED physicians. DESIGN, SETTINGS, AND PARTICIPANTS: Patients ≥18 years, with chest pain of suspected cardiac origin presented by ambulance to the EDs of four regional hospitals, were prospectively enrolled between October 2018 and April 2019. OUTCOMES MEASURE AND ANALYSIS: The primary endpoint was interobserver agreement of the HEART-scores calculated by ambulance nurses compared to those calculated by ED physicians. Agreement was measured using Cohen's Kappa (K) both for overall HEART-score and dichotomized HEART categories. A secondary endpoint was the occurrence of a MACE at 30 days after inclusion. MAIN RESULTS: A total of 307 patients were enrolled of which 166 patients were male (54%). The mean age was 64.8 years. In 23% (95% confidence interval, 18-27), patients were scored in the low-risk category by both ambulance nurses and ED physicians. The K for the overall HEART-score compared between ambulance nurses and ED physicians was 0.514. The K for the low-risk category versus intermediate and high-risk category was 0.591. Both are defined as 'moderate'. MACE within 30 days occurred in 64 patients (21%). In the low-risk group as defined by the ambulance nurses, there was a 7% risk of MACE compared to an average 5% MACE risk in the ED physician group. CONCLUSIONS: The moderate interobserver agreement of the HEART-score does not currently support the use of the HEART-score by ambulance nurses in a prehospital setting. Training for prehospital nurses is vital to ensure that they are able to calculate the HEART-score accurately.

The revised Approved Instructional Resources score: An improved quality evaluation tool for online educational resources.

BACKGROUND: Free Open-Access Medical education (FOAM) use among residents continues to rise. However, it often lacks quality assurance processes and residents receive little guidance on quality assessment. The Academic Life in Emergency Medicine Approved Instructional Resources tool (AAT) was created for FOAM appraisal by and for expert educators and has demonstrated validity in this context. It has yet to be evaluated in other populations. OBJECTIVES: We assessed the AAT's usability in a diverse population of practicing emergency medicine (EM) physicians, residents, and medical students; solicited feedback; and developed a revised tool. METHODS: As part of the Medical Education Translational Resources: Impact and Quality (METRIQ) study, we recruited medical students, EM residents, and EM attendings to evaluate five FOAM posts with the AAT and provide quantitative and qualitative feedback via an online survey. Two independent analysts performed a qualitative thematic analysis with discrepancies resolved through discussion and negotiated consensus. This analysis informed development of an initial revised AAT, which was then further refined after pilot testing among the author group. The final tool was reassessed for reliability. RESULTS: Of 330 recruited international participants, 309 completed all ratings. The Best Evidence in Emergency Medicine (BEEM) score was the component most frequently reported as difficult to use. Several themes emerged from the qualitative analysis: for ease of use-understandable, logically structured, concise, and aligned with educational value. Limitations include deviation from questionnaire best practices, validity concerns, and challenges assessing evidence-based medicine. Themes supporting its use include evaluative utility and usability. The author group pilot tested the initial revised AAT, revealing a total score average measure intraclass correlation coefficient (ICC) of moderate reliability (ICC = 0.68, 95% confidence interval [CI] = 0 to 0.962). The final AAT's average measure ICC was 0.88 (95% CI = 0.77 to 0.95). CONCLUSIONS: We developed the final revised AAT from usability feedback. The new score has significantly increased usability, but will need to be reassessed for reliability in a broad population.

Intra-patient reproducibility of myocardial SPECT imaging with 201Tl.

BACKGROUND: To define the physical and clinical reproducibility of (201)Tl myocardial perfusion SPECT (MPS), this study assesses the variation between two repeated rest (201)Tl MPS with repositioning only, with a two-hour time interval and with phantom measurements as a reference. METHODS: Three anthropomorphic thorax phantoms were filled with (201)Tl. For each phantom five repeated (201)Tl MPS were obtained. In addition, in 20 patients repeated (201)Tl rest-MPS and in 26 patients early and delayed (201)Tl rest-MPS were performed. Quantitative analysis was done using MunichHeart. Statistical methods were used to calculate variability. Visual analysis was performed by 2 independent observers. RESULTS: The average variation between repeated phantom MPS was 0.5% (95% confidence interval (CI): -0.4% to 1.4%). For patient scans this was -5.0% (95% CI: -2.5% to -7.5%) and between early and delayed (201)Tl MPS -15.5% (95% CI: -11.7% to -19.3%). Visual assessment revealed no clinical significant differences between rest (201)Tl and repeated or delayed (201)Tl MPS. CONCLUSIONS: Repositioning in phantom (201)Tl MPS does not cause significant variation. Repeated (201)Tl MPS in patients shows 5.0% decrease of (201)Tl in 30 minutes, which increases to 15% during a two-hour time interval without quantitative or visual regional differences. This decrease indicates a time-related washout of (201)Tl, but does not change clinical diagnosis.

The HEART score in predicting major adverse cardiac events in patients presenting to the emergency department with possible acute coronary syndrome: protocol for a systematic review and meta-analysis.

BACKGROUND: Acute coronary syndrome (ACS) is a common, sometimes difficult to diagnose spectrum of diseases occurring after abrupt reduction in blood flow through a coronary artery. Given the diagnostic challenge, it is sensible for emergency physicians to have an approach to prognosticate patients with possible ACS. Multiple prediction models have been developed to help identify patients at increased risk of adverse outcomes. The HEART score is the first model to be derived, validated, and undergo clinical impact studies in emergency department (ED) patients with possible ACS. OBJECTIVE: To develop a protocol for a prognostic systematic review of the literature evaluating the HEART score as a predictor of major adverse cardiac events (MACE) in patients presenting to the ED with possible ACS. METHODS/DESIGN: This protocol is reported according to the PRISMA-P statement and is registered on PROSPERO. All methodological tools to be used are endorsed by the Cochrane Prognosis Methods Group. Pre-defined eligibility criteria are provided. Multiple strategies will be used to identify potentially relevant studies. Studies will be selected and data extracted using standardised forms based on the CHARMS checklist. The QUIPS tool will be used to assess the risk of bias within individual studies. Outcome measures will include prevalence, risk ratio, and absolute risk reduction for MACE within 6 weeks of ED evaluation, comparing HEART scores 0-3 versus 4-10. HEART score prognostic performance will be evaluated with the concordance (C) statistic (model discrimination), observed to expected events ratio (model calibration), and a decision curve analysis. Reporting biases and methodological, clinical, and statistical heterogeneity will be scrutinised. Unless deemed inappropriate, a meta-analysis and pre-defined subgroup and sensitivity analyses will be performed. Overall judgements about evidence quality and strength of recommendations will be summarised using the GRADE approach. DISCUSSION: This review will identify, select, and appraise studies evaluating the prognostic performance of the HEART score, producing results of interest to emergency physicians. These results may encourage shared clinical decision-making in the ED by facilitating risk communication with patients and health care providers. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2017 CRD42017084400 .