2023 Society for Academic Emergency Medicine Consensus Conference on Precision Emergency Medicine: Development of a policy-relevant, patient-centered research agenda.

OBJECTIVES: Precision medicine is data-driven health care tailored to individual patients based on their unique attributes, including biologic profiles, disease expressions, local environments, and socioeconomic conditions. Emergency medicine (EM) has been peripheral to the precision medicine discourse, lacking both a unified definition of precision medicine and a clear research agenda. We convened a national consensus conference to build a shared mental model and develop a research agenda for precision EM. METHODS: We held a conference to (1) define precision EM, (2) develop an evidence-based research agenda, and (3) identify educational gaps for current and future EM clinicians. Nine preconference workgroups (biomedical ethics, data science, health professions education, health care delivery and access, informatics, omics, population health, sex and gender, and technology and digital tools), comprising 84 individuals, garnered expert opinion, reviewed relevant literature, engaged with patients, and developed key research questions. During the conference, each workgroup shared how they defined precision EM within their domain, presented relevant conceptual frameworks, and engaged a broad set of stakeholders to refine precision EM research questions using a multistage consensus-building process. RESULTS: A total of 217 individuals participated in this initiative, of whom 115 were conference-day attendees. Consensus-building activities yielded a definition of precision EM and key research questions that comprised a new 10-year precision EM research agenda. The consensus process revealed three themes: (1) preeminence of data, (2) interconnectedness of research questions across domains, and (3) promises and pitfalls of advances in health technology and data science/artificial intelligence. The Health Professions Education Workgroup identified educational gaps in precision EM and discussed a training roadmap for the specialty. CONCLUSIONS: A research agenda for precision EM, developed with extensive stakeholder input, recognizes the potential and challenges of precision EM. Comprehensive clinician training in this field is essential to advance EM in this domain.

Frequency of Discordant Documentation of Patient Race and Ethnicity.

This cohort study examines longitudinal changes in race and ethnicity assignment in US hospitals.

Evaluating the pediatric mental health care continuum at an American health system.

Objective: To describe trends in the pediatric mental health care continuum and identify potential gaps in care coordination. Methods: We used electronic medical record data from October 2016 to September 2019 to characterize the prevalence of mental health issues in the pediatric population at a large American health system. This was a single institution case study. From the electronic medical record data, primary mental health discharge and readmission diagnoses were identified using International Classification of Diseases (ICD-9-CM, ICD-10-CM) codes. The electronic medical record was queried for mental health-specific diagnoses as defined by International Classification of Diseases classification, analysis of which was facilitated by the fact that only 176 mental health codes were billed for. Additionally, prevalence of care navigation encounters was assessed through electronic medical record query, as care navigation encounters are specifically coded. These encounter data was then segmented by care delivery setting. Results: Major depressive disorder and other mood disorders comprised 49.6% and 89.4% of diagnoses in the emergency department and inpatient settings respectively compared to 9.0% of ambulatory care diagnoses and were among top reasons for readmission. Additionally, only 1% of all ambulatory care encounters had a care navigation component, whereas 86% of care navigation encounters were for mental health-associated reasons. Conclusions: Major depressive disorder and other mood disorders were more common diagnoses in the emergency department and inpatient settings, which could signal gaps in care coordination. Bridging potential gaps in care coordination could reduce emergency department and inpatient utilization through increasing ambulatory care navigation resources, improving training, and restructuring financial incentives to facilitate ambulatory care diagnosis and management of major depressive disorder and mood disorders. Furthermore, health systems can use our descriptive analytic approach to serve as a reasonable measure of the current state of pediatric mental health care in their own patient population.

National Trends in Vital Sign Abnormalities at Arrival to the Emergency Department.

INTRODUCTION: Recent reports suggest rising intensity of emergency department (ED) billing practices, sparking concerns that this may represent up-coding. However, it may reflect increasing severity and complexity of care in the ED population. We hypothesize that this in part may be reflected in more severe manifestations of illness as indicated by vital sign abnormalities. METHODS: Using 18 years of data from the National Hospital Ambulatory Medical Care Survey, we conducted a retrospective secondary analysis of adults (>18 years). We assessed standard vital signs using weighted descriptive statistics (heart rate, oxygen saturation, temperature, and systolic blood pressure [SBP]), as well as hypotension and tachycardia. Finally, we evaluated for differing effects stratifying by subpopulations of interest, including age (<65 vs ≥65), payer type, arrival by ambulance, and high-risk diagnoses. RESULTS: In total there were 418,849 observations representing 1,745,368,303 ED visits. We found only minimal variations in vital signs over the study period: heart rate (median 85, interquartile range [IQR] 74-97); oxygen saturation (median 98, IQR 97-99); temperature (median 98.1, IQR 97.6-98.6); and SBP (median 134, IQR 120-149). Similar results were found among the subpopulations tested. The proportion of visits with hypotension decreased (first/last year difference 0.5% [95% CI 0.2%-0.7%]) while there was no difference in the proportion of patients with tachycardia. CONCLUSIONS: Arrival vital signs in the ED have largely remained unchanged or improved over the most recent 18 years of nationally representative data, even for key subpopulations. Greater intensity in ED billing practices is not explained by changes in arrival vital signs.

How do current police practices impact trauma care in the prehospital setting? A scoping review.

Objective: In the United States, police are often important co-responders to 911 calls with emergency medical services for medical emergencies. To date, there remains a lack of a comprehensive understanding of the mechanisms by which police response modifies time to in-hospital medical care for traumatically injured patients. Further, it remains unclear if differentials exist within or between communities. A scoping review was performed to identify studies evaluating prehospital transport of traumatically injured patients and the role or impact of police involvement. Methods: PubMed, SCOPUS, and Criminal Justice Abstracts databases were utilized to identify articles. English-language, US-based, peer-reviewed articles published on or prior to March 30, 2022 were eligible for inclusion. Results: Of 19,437 articles initially identified, 70 articles were selected for full review and 17 for final inclusion. Key findings included (1) current law enforcement practices involving scene clearance introduce the potential for delayed patient transport but to date there is little research quantifying delays; (2) police transport protocols may decrease transport times; and (3) there are no studies examining the potential impact of scene clearance practices at the patient or community level. Conclusions: Our results highlight that police are often the first on scene when responding to traumatic injuries and have an active role via scene clearance or, in some systems, patient transport. Despite the significant potential for impact on patient well-being, there remains a paucity of data examining and driving current practices.

Disparate Utilization of Urine Drug Screen Nationwide in the Evaluation of Acute Chest Pain.

INTRODUCTION: Urine drug screens (UDS) have unproven clinical utility in emergency department (ED) chest pain presentations. A test with such limited clinical utility may exponentiate biases in care, but little is known about the epidemiology of UDS use for this indication. We hypothesized that UDS utilization varies nationally across race and gender. METHODS: This was a retrospective observational analysis of adult ED visits for chest pain in the 2011-2019 National Hospital Ambulatory Medical Care Survey. We calculated the utilization of UDS across race/ethnicity and gender and then characterized predictors of use via adjusted logistic regression models. RESULTS: We analyzed 13,567 adult chest pain visits, representative of 85.8 million visits nationally. Use of UDS occurred for 4.6% of visits (95% CI 3.9%-5.4%). White females underwent UDS at 3.3% of visits (95% CI 2.5%-4.2%), and Black females at 4.1% (95% CI 2.9%-5.2%). White males were tested at 5.8% of visits (95% CI 4.4%-7.2%), while Black males were tested at 9.3% of visits (95% CI 6.4%-12.2%). A multivariate logistic regression model including race, gender, and time period shows significantly increased odds of ordering UDS for Black patients (odds ratio [OR] 1.45 (95% CI 1.11-1.90, p = 0.007)) and male patients (OR 2.0 (95% CI 1.55-2.58, p < 0.001) as compared to White patients and female patients. CONCLUSION: We identified wide disparities in the utilization of UDS for the evaluation of chest pain. If UDS were used at the rate observed for White women, Black men would undergo nearly 50,000 fewer tests annually. Future research should weigh the potential of the UDS to magnify biases in care against the unproven clinical utility of the test.

A Quality Framework to Address Racial and Ethnic Disparities in Emergency Department Care.

The emergency department serves as a vital source of health care for residents in the United States, including as a safety net. However, patients from minoritized racial and ethnic groups have historically experienced disproportionate barriers to accessing health care services and lower quality of services than White patients. Quality measures and their application to quality improvement initiatives represent a critical opportunity to incentivize health care systems to advance health equity and reduce health disparities. Currently, there are no nationally recognized quality measures that track the quality of emergency care delivery by race and ethnicity and no published frameworks to guide the development and prioritization of quality measures to reduce health disparities in emergency care. To address these gaps, the American College of Emergency Physicians (ACEP) convened a working group of experts in quality measurement, health disparities, and health equity to develop guidance on establishing quality measures to address racial and ethnic disparities in the provision of emergency care. Based on iterative discussion over 3 working group meetings, we present a summary of existing emergency medicine quality measures that should be adapted to track racial and ethnic disparities, as well as a framework for developing new measures that focus on disparities in access to emergency care, care delivery, and transitions of care.

Identifying Strategies to Boost COVID-19 Vaccine Acceptance in the United States.

This study presents the results of an evaluation of the root causes of COVID-19 vaccine hesitancy to inform strategies to boost vaccine acceptance among vaccine-hesitant populations in the United States. The authors conducted a literature review of the causes of vaccine hesitancy and vaccine acceptance; focus groups with patients, pre-hospital first responders, and hospital-based health care providers; a social media platform sentiment analysis to review attitudes regarding the COVID-19 vaccine; and a roundtable discussion with experts on vaccine hesitancy. Drawing on this mixed-methods analysis, the authors recommend strategies to help boost COVID-19 vaccine acceptance in the United States, grouping them according to three overall goals: boosting confidence in the safety and effectiveness of the COVID-19 vaccines, combating complacency about the pandemic, and increasing the convenience of getting vaccinated. The authors emphasize that combating misinformation about the COVID-19 vaccine is key to achieving these goals. These recommendations can inform the development of a toolkit of strategies to reach herd immunity and end the pandemic.

The association of fire or police first responder initiated interventions with out of hospital cardiac arrest survival.

OBJECTIVE: Fire and police first responders are often the first to arrive in medical emergencies and provide basic life support services until specialized personnel arrive. This study aims to evaluate rates of fire or police first responder-initiated cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use, as well as their associated impact on out-of-hospital cardiac arrest (OHCA) outcomes. METHODS: We completed a secondary data analysis of the MI-CARES registry from 2014 to 2019. We reported rates of CPR initiation and AED use by fire or police first responders. Multilevel modeling was utilized to evaluate the relationship between fire/police first responder-initiated interventions and outcomes of interest: ROSC upon emergency department arrival, survival to hospital discharge, and good neurologic outcome. RESULTS: Our cohort included 25,067 OHCA incidents. We found fire or police first responders initiated CPR in 31.8% of OHCA events and AED use in 6.1% of OHCA events. Likelihood of sustained ROSC on ED arrival after CPR initiated by a fire/police first responder was not statistically different as compared to EMS initiated CPR (aOR 1.01, CI 0.93-1.11). However, fire/police first responder interventions were associated with significantly higher odds of survival to hospital discharge and survival with good neurologic outcome (aOR 1.25, 95% CI 1.08-1.45 and aOR 1.40, 95% CI 1.18-1.65, respectively). Similar associations were see when examining fire or police initiated AED use. CONCLUSIONS: Fire or police first responders may be an underutilized, potentially powerful mechanism for improving OHCA survival. Future studies should investigate barriers and opportunities for increasing first responder interventions by these groups in OHCA.

Interest in Serving the Underserved: Role of Race, Gender, and Medical Specialty Plans.

Introduction: Medical students often express their plans to care for medically underserved populations, but little is known about how this interest remains during medical school (MS). This study examined how self-reported interest in working with medically underserved communities may change during MS training based on several student characteristics. Methods: A secondary data analysis of all student records in the Electronic Residency Application Service (ERAS) from 2005 to 2010 is presented. Predictors included gender, under-represented in medicine (URiM) status, age, academic metrics, career interest, and medical specialty choice. Outcomes included interest in caring for medically underserved populations when entering MS, graduating MS, and graduating MS controlling for entering interest. Results: The total population included 6890 student records (49.5% women and 18.2% URiM). Women had a higher likelihood of being interested in practicing in underserved communities when entering and graduating MS (odds ratio [OR] 1.55, 95% confidence interval [CI] 1.37-1.77; OR 1.24, 95% CI 1.09-1.40). For all outcomes, URiM students had a higher likelihood of planning on a career with underserved populations compared with their non-URiM peers. Compared with Emergency Medicine, Internal Medicine/Pediatrics and Family Medicine had a higher likelihood of plans to work with underserved populations upon entering, graduating, and at graduation controlling for entering interest. Discussion: Gender, race, and specialty choice all had meaningful associations with a student's plans on practice in an underserved community. This study's findings can help support efforts to improve MS diversity nationally and drive study on cultural effects embedded within medical specialty identity.

Variation in pre-hospital outcomes after out-of-hospital cardiac arrest in Michigan.

AIM: Care by emergency medical service (EMS) agencies is critical for optimizing prehospital outcomes following out-of-hospital cardiac arrest (OHCA). We explored whether substantial differences exist in prehospital outcomes across EMS agencies in Michigan-specifically focusing on rates of sustained return of spontaneous circulation (ROSC) upon emergency department (ED) arrival. METHODS: Using data from Michigan Cardiac Arrest Registry to Enhance Survival (MI-CARES) for years 2014-2017, we calculated rates of sustained ROSC upon ED arrival across EMS agencies in Michigan. We used hierarchical logistic regression models that accounted for patient, arrest-, community-, and response-level characteristics to determine adjusted rates of sustained ROSC among EMS agencies. RESULTS: A total of 103 EMS agencies and 20,897 OHCA cases were included. Average age of the cohort was 62.5 years (SD = 19.6), 39.7% were female, and 17.9% had an initial shockable rhythm due to ventricular fibrillation or pulseless ventricular tachycardia. The adjusted rate of sustained ROSC upon ED arrival across all EMS agencies was 23.8% with notable variation across EMS agencies (interquartile range [IQR], 20.5-29.2%). The top five EMS agencies had mean adjusted rates of sustained ROSC upon ED arrival of 42.7% (95% CI: 34.6-51.1%) while the bottom five had mean adjusted rates of 9.8% (95% CI: 7.6-12.7%). CONCLUSIONS: Substantial variation in sustained ROSC upon ED arrival exists across EMS agencies in Michigan after adjusting for patient-, arrest, community-, and response-level features. Such differences suggest opportunities to identify and improve best practices in EMS agencies to advance OHCA care.

Enhancing Prehospital Outcomes for Cardiac Arrest (EPOC) study: sequential mixed-methods study protocol in Michigan, USA.

INTRODUCTION: Out-of-hospital cardiac arrest (OHCA) is a common, life-threatening event encountered routinely by first responders, including police, fire and emergency medical services (EMS). Current literature suggests that there is significant regional variation in outcomes, some of which may be related to modifiable factors. Yet, there is a persistent knowledge gap regarding strategies to guide quality improvement efforts in OHCA care and, by extension, survival. The Enhancing Prehospital Outcomes for Cardiac Arrest (EPOC) study aims to fill these gaps and to improve outcomes. METHODS AND ANALYSIS: This mixed-methods study includes three aims. In aim I, we will define variation in OHCA survival to the emergency department (ED) among EMS agencies that participate in the Michigan Cardiac Arrest Registry to Enhance Survival (CARES) in order to sample EMS agencies with high-survival and low-survival outcomes. In aim II, we will conduct site visits to emergency medical systems-including 911/dispatch, police, non-transport fire, and EMS agencies-in approximately eight high-survival and low-survival communities identified in aim I. At each site, key informant interviews and a multidisciplinary focus group will identify themes associated with high OHCA survival. Transcripts will be coded using a structured codebook and analysed through thematic analysis. Results from aims I and II will inform the development of a survey instrument in aim III that will be administered to all EMS agencies in Michigan. This survey will test the generalisability of factors associated with increased OHCA survival in the qualitative work to ultimately build an EPOC Toolkit which will be distributed to a broad range of stakeholders as a practical 'how-to' guide to improve outcomes. ETHICS AND DISSEMINATION: The EPOC study was deemed exempt by the University of Michigan Institutional Review Board. Findings will be compiled in an 'EPOC Toolkit' and disseminated in the USA through partnerships including, but not limited to, policymakers, EMS leadership and health departments.

PERIODONTAL DISEASE AND AGE-RELATED MACULAR DEGENERATION: Results From the National Health and Nutrition Examination Survey III.

PURPOSE: To study the association between periodontal disease (PD) and age-related macular degeneration (AMD). METHODS: For this cross-sectional analysis, 8,208 adults aged 40 years or older with retinal photographs graded for AMD were used from the National Health and Nutrition Examination Survey III. National Health and Nutrition Examination Survey III standardized dental measurements of PD status (defined as loss of >3 mm of attachment between the gum and tooth in at least 10% of sites measured). Participants were stratified into 60 years or younger and older than 60 years of age groups. Association between PD and AMD was assessed while controlling for sex, race, education, poverty income ratio, smoking, hypertension, body mass index, cardiovascular disease, and C-reactive protein. RESULTS: In this population, a total of 52.30% had PD, and the prevalence of AMD was 11.45%. Logistic regression model controlled for confounders and stratified by age 60 years or younger versus older than 60 years showed PD to be independently associated with an increased risk for AMD (odds ratio = 1.96, 95% confidence interval = 1.22-3.14, P = 0.006) for those aged 60 years or younger but not for subjects older than 60 years (odds ratio = 1.32, confidence interval = 0.93-1.90, P = 0.120). CONCLUSION: In this population-based study, PD is independently associated with AMD in those aged 60 years or younger.

Severity-adjusted mortality in trauma patients transported by police.

STUDY OBJECTIVE: Two decades ago, Philadelphia began allowing police transport of patients with penetrating trauma. We conduct a large, multiyear, citywide analysis of this policy. We examine the association between mode of out-of-hospital transport (police department versus emergency medical services [EMS]) and mortality among patients with penetrating trauma in Philadelphia. METHODS: This is a retrospective cohort study of trauma registry data. Patients who sustained any proximal penetrating trauma and presented to any Level I or II trauma center in Philadelphia between January 1, 2003, and December 31, 2007, were included. Analyses were conducted with logistic regression models and were adjusted for injury severity with the Trauma and Injury Severity Score and for case mix with a modified Charlson index. RESULTS: Four thousand one hundred twenty-two subjects were identified. Overall mortality was 27.4%. In unadjusted analyses, patients transported by police were more likely to die than patients transported by ambulance (29.8% versus 26.5%; OR 1.18; 95% confidence interval [CI] 1.00 to 1.39). In adjusted models, no significant difference was observed in overall mortality between the police department and EMS groups (odds ratio [OR] 0.78; 95% CI 0.61 to 1.01). In subgroup analysis, patients with severe injury (Injury Severity Score >15) (OR 0.73; 95% CI 0.59 to 0.90), patients with gunshot wounds (OR 0.70; 95% CI 0.53 to 0.94), and patients with stab wounds (OR 0.19; 95% CI 0.08 to 0.45) were more likely to survive if transported by police. CONCLUSION: We found no significant overall difference in adjusted mortality between patients transported by the police department compared with EMS but found increased adjusted survival among 3 key subgroups of patients transported by police. This practice may augment traditional care.

Access to care for patients with time-sensitive conditions in Pennsylvania.

STUDY OBJECTIVE: Collective knowledge and coordination of vital interventions for time-sensitive conditions (ST-segment elevation myocardial infarction [STEMI], stroke, cardiac arrest, and septic shock) could contribute to a comprehensive statewide emergency care system, but little is known about population access to the resources required. We seek to describe existing clinical management strategies for time-sensitive conditions in Pennsylvania hospitals. METHODS: All Pennsylvania emergency departments (EDs) open in 2009 were surveyed about resource availability and practice patterns for time-sensitive conditions. The frequency with which EDs provided essential clinical bundles for each condition was assessed. Penalized maximum likelihood regressions were used to evaluate associations between ED characteristics and the presence of the 4 clinical bundles of care. We used geographic information science to calculate 60-minute ambulance access to the nearest facility with these clinical bundles. RESULTS: The percentage of EDs providing each of the 4 clinical bundles in 2009 ranged from 20% to 57% (stroke 20%, STEMI 32%, cardiac arrest 34%, sepsis 57%). For STEMI and stroke, presence of a board-certified/board-eligible emergency physician was significantly associated with presence of a clinical bundle. Only 8% of hospitals provided all 4 care bundles. However, 53% of the population was able to reach this minority of hospitals within 60 minutes. CONCLUSION: Reliably matching patient needs to ED resources in time-dependent illness is a critical component of a coordinated emergency care system. Population access to critical interventions for the time-dependent diseases discussed here is limited. A population-based planning approach and improved coordination of care could improve access to interventions for patients with time-sensitive conditions.

A pilot study describing access to emergency care in two states using a model emergency care categorization system.

OBJECTIVES: The Institute of Medicine (IOM)'s "Future of Emergency Care" report recommended the categorization and regionalization of emergency care, but no uniform system to categorize hospital emergency care capabilities has been developed. The absence of such a system limits the ability to benchmark outcomes, to develop regional systems of care, and of patients to make informed decisions when seeking emergency care. The authors sought to pilot the deployment of an emergency care categorization system in two states. METHODS: A five-tiered emergency department (ED) categorization system was designed, and a survey of all Pennsylvania and Wisconsin EDs was conducted. This 46-item survey described hospital staffing, characteristics, resources, and practice patterns. Based on responses, EDs were categorized as limited, basic, advanced, comprehensive, and pediatric critical care capable. Prehospital transport times were then used to determine population access to each level of care. RESULTS: A total of 247 surveys were received from the two states (247 of 297, 83%). Of the facilities surveyed, roughly one-quarter of hospitals provided advanced care, 10.5% provided comprehensive care, and 1.6% provided pediatric critical care. Overall, 75.1% of the general population could reach an advanced or comprehensive ED within 60 minutes by ground transportation. Among the pediatric population (age 14 years and younger), 56.2% could reach a pediatric critical care or comprehensive ED, with another 19.5% being able to access an advanced ED within 60 minutes. CONCLUSIONS: Using this categorization system, fewer than half of all EDs provide advanced or comprehensive emergency care. While the majority of the population has access to advanced or comprehensive care within an hour, a significant portion (25%) does not. This article describes how an ED categorization scheme could be developed and deployed across the United States. There are implications for prehospital planning, patient decision-making, outcomes measurement, interfacility transfer coordination, and development of regional emergency care systems.

Relationship between body mass index and prognosis of patients presenting with potential acute coronary syndromes.

OBJECTIVES: Studies examining the relationship between obesity and acute coronary syndrome (ACS) have been limited to patients with confirmed diagnoses. The authors sought to determine the relationship between body mass index (BMI) and 30-day cardiovascular events in emergency department (ED) patients with potential ACS. METHODS: This was a secondary analysis of a prospective cohort study of patients who presented to the ED with potential ACS. Patients were stratified according to their BMI: underweight (BMI < 18.49 kg/m(2) ), normal weight (BMI = 18.5 to 24.99 kg/m(2) ), overweight (BMI = 25 to 29.99 kg/m(2) ), obese (BMI = 30 to 34.99 kg/m(2) ), and very obese (BMI > 35 kg/m(2) ). The primary outcome was acute myocardial infarction (AMI), death, or revascularization within 30 days of presentation. A logistic regression analysis was used to adjust for confounding variables and adjusted odds ratios (aOR) with 95% confidence intervals (CIs) are presented for cardiac events and readmission outcomes. RESULTS: Of the 3,946 patients included in this study, 73 (1.9%) were underweight, 911 (23%) were normal weight, 1,199 (30.4%) were overweight, 872 (22.1%) were obese, and 891 (22.6%) were very obese. Although increased levels of obesity were associated with a greater number of cardiac risk factors, there was no difference in 30-day cardiovascular events between those of normal weight and underweight (aOR = 1.1; 95% CI = 0.4 to 2.7), overweight (aOR = 1.0; 95% CI = 0.7 to 1.4), obese (aOR = 1.2; 95% CI = 0.8 to1.7), or very obese (aOR = 0.8; 95% CI = 0.5 to 1.3). Those who were underweight were more likely to be readmitted within 30 days (aOR = 1.9; 95% CI = 1.0 to 3.7), and those who were very obese were less likely to be readmitted within 30 days (aOR = 0.7; 95% CI = 0.5 to 0.9). CONCLUSIONS: Among patients who present to the ED with potential ACS, BMI is not associated with higher risk of cardiovascular outcomes at 30 days.

HEART score to further risk stratify patients with low TIMI scores.

OBJECTIVE: The ability to risk stratify patients presenting to the emergency department (ED) with potential acute coronary syndrome (ACS) is critical. The thrombolysis in myocardial infarction (TIMI) risk score can risk stratify ED patients with potential ACS but cannot identify patients safe for ED discharge. The symptom-based HEART score identifies very low-risk patients. Our hypothesis was that patients with a TIMI score of 0 or 1 may be stratified further with the HEART score to identify a group of patients at less than 1% risk of 30-day cardiovascular events. METHODS: We conducted a secondary analysis of a prospective cohort study in a tertiary care hospital ED. Patients with potential ACS who were >30 years of age were included. Data collected included demographics, history, electrocardiogram, laboratories, and components of the TIMI and HEART scores. Follow-up was conducted by structured record review and phone. The main outcome was a composite of death, acute myocardial infarction, or revascularization at 30 days. RESULTS: There were 8815 patients enrolled (mean age, 52.8 ± 15.1 years; 57% women, and 69% black). At 30 days, the composite event rate was 8.0% (660 patients): 108 deaths, 410 acute myocardial infarction, and 301 revascularizations. Of the 485 patients with both a TIMI score of 0 and a HEART score of 0, there were no cardiovascular events (95% confidence interval, 0-0.8%); but no other score combination had an upper limit confidence interval less than 1%. CONCLUSION: At all levels of TIMI score, the HEART score was able to further substratify patients with respect to 30-day risk. A HEART score of 0 in a patient with a TIMI of 0 identified a group of patients at less than 1% risk for 30-day adverse events.