Provider attitudes towards quality improvement for myocardial infarction care in northern Tanzania

INTRODUCTION

Myocardial Infarction (MI) is a leading cause of death worldwide. In high income countries, quality improvement strategies have played an important role in increasing uptake of evidence-based MI care and improving MI outcomes. The incidence of MI in sub-Saharan Africa is rising, but uptake of evidence-based care in northern Tanzania is low. There are currently no published quality improvement interventions from the region. The objective of this study was to determine provider attitudes towards a planned quality improvement intervention for MI care in northern Tanzania.

METHODS

This study was conducted at a zonal referral hospital in northern Tanzania. A 41-question survey, informed by the Theoretical Framework for Acceptability, was developed by an interdisciplinary team from Tanzania and the United States. The survey, which explored provider attitudes towards MI care improvement, was administered to key provider stakeholders (physicians, nurses, and hospital administrators) using convenience sampling.

RESULTS

A total of 140 providers were enrolled, including 82 (58.6%) nurses, 56 (40.0%) physicians, and 2 (1.4%) hospital administrators. Most participants worked in the Emergency Department or inpatient medical ward. Providers were interested in participating in a quality improvement project to improve MI care at their facility, with 139 (99.3%) strongly agreeing or agreeing with this statement. All participants agreed or strongly agreed that improvements were needed to MI care pathways at their facility. Though their facility has an MI care protocol, only 88 (62.9%) providers were aware of it. When asked which intervention would be the single-most effective strategy to improve MI care, the two most common responses were provider training (n = 66, 47.1%) and patient education (n = 41, 29.3%).

CONCLUSION

Providers in northern Tanzania reported strongly positive attitudes towards quality improvement interventions for MI care. Locally-tailored interventions to improve MI should include provider training and patient education strategies.

Evaluating the performance of the HEART score in a Tanzanian emergency department

OBJECTIVE

The HEART score successfully risk stratifies emergency department (ED) patients with chest pain in high-income settings. However, this tool has not been validated in low-income countries.

METHODS

This is a secondary analysis of a prospective observational study that was conducted in a Tanzanian ED from January 2019 through January 2023. Adult patients with chest pain were consecutively enrolled, and their presenting symptoms and medical history were recorded. Electrocardiograms and point-of-care troponin assays were obtained for all participants. Thirty-day follow-up was conducted, assessing for major adverse cardiac events (MACEs), defined as death, myocardial infarction, or coronary revascularization (coronary artery bypass grafting or percutaneous coronary intervention). HEART scores were calculated for all participants. Likelihood ratios, sensitivity, specificity, and negative predictive values (NPVs) were calculated for each HEART cutoff score to predict 30-day MACEs, and area under the curve (AUC) was calculated from the receiver operating characteristic curve.

RESULTS

Of 927 participants with chest pain, the median (IQR) age was 61 (45.5-74.0) years. Of participants, 216 (23.3%) patients experienced 30-day MACEs, including 163 (17.6%) who died, 48 (5.2%) with myocardial infarction, and 23 (2.5%) with coronary revascularization. The positive likelihood ratio for each cutoff score ranged from 1.023 (95% CI 1.004-1.042; cutoff ≥ 1) to 3.556 (95% CI 1.929-6.555; cutoff ≥ 7). The recommended cutoff of ≥4 to identify patients at high risk of MACEs yielded a sensitivity of 59.4%, specificity of 52.8%, and NPV of 74.7%. The AUC was 0.61.

CONCLUSIONS

Among patients with chest pain in a Tanzanian ED, the HEART score did not perform as well as in high-income settings. Locally validated risk stratification tools are needed for ED patients with chest pain in low-income countries.

Adapting an Intervention to Improve Acute Myocardial Infarction Care in Tanzania: Co-Design of the MIMIC Intervention

Background

Uptake of evidence-based care for acute myocardial infarction (AMI) is suboptimal in Tanzania, but there are currently no published interventions to improve AMI care in sub-Saharan Africa.

Objectives

Co-design a quality improvement intervention for AMI care tailored to local contextual factors.

Methods

An interdisciplinary design team consisting of 20 physicians, nurses, implementation scientists, and administrators met from June 2022 through August 2023. Half of the design team consisted of representatives from the target audience, emergency department physicians and nurses at a referral hospital in northern Tanzania. The design team reviewed multiple published quality improvement interventions focusing on ED-based AMI care. After selecting a multicomponent intervention to improve AMI care in Brazil (BRIDGE-ACS), the design team used the ADAPT-ITT framework to adapt the intervention to the local context.

Findings

The design team audited current AMI care processes at the study hospital and reviewed qualitative data regarding barriers to care. Multiple adaptations were made to the original BRIDGE-ACS intervention to suit the local context, including re-designing the physician reminder system and adding patient educational materials. Additional feedback was sought from topical experts, including patients with AMI. Draft intervention materials were iteratively refined in response to feedback from experts and the design team. The finalized intervention, Multicomponent Intervention to Improve Myocardial Infarction Care in Tanzania (MIMIC), consisted of five core components: physician reminders, pocket cards, champions, provider training, and patient education.

Conclusion

MIMIC is the first locally tailored intervention to improve AMI care in sub-Saharan Africa. Future studies will evaluate implementation outcomes and efficacy.

RobOCTNet: Robotics and Deep Learning for Referable Posterior Segment Pathology Detection in an Emergency Department Population

Purpose

To evaluate the diagnostic performance of a robotically aligned optical coherence tomography (RAOCT) system coupled with a deep learning model in detecting referable posterior segment pathology in OCT images of emergency department patients.

Methods

A deep learning model, RobOCTNet, was trained and internally tested to classify OCT images as referable versus non-referable for ophthalmology consultation. For external testing, emergency department patients with signs or symptoms warranting evaluation of the posterior segment were imaged with RAOCT. RobOCTNet was used to classify the images. Model performance was evaluated against a reference standard based on clinical diagnosis and retina specialist OCT review.

Results

We included 90,250 OCT images for training and 1489 images for internal testing. RobOCTNet achieved an area under the curve (AUC) of 1.00 (95% confidence interval [CI], 0.99-1.00) for detection of referable posterior segment pathology in the internal test set. For external testing, RAOCT was used to image 72 eyes of 38 emergency department patients. In this set, RobOCTNet had an AUC of 0.91 (95% CI, 0.82-0.97), a sensitivity of 95% (95% CI, 87%-100%), and a specificity of 76% (95% CI, 62%-91%). The model's performance was comparable to two human experts' performance.

Conclusions

A robotically aligned OCT coupled with a deep learning model demonstrated high diagnostic performance in detecting referable posterior segment pathology in a cohort of emergency department patients.

Translational Relevance

Robotically aligned OCT coupled with a deep learning model may have the potential to improve emergency department patient triage for ophthalmology referral.

Longitudinal ECG changes among adults with HIV in Tanzania: A prospective cohort study

The prevalence of cardiovascular disease (CVD) is rising among people with HIV (PWH) in sub-Saharan Africa (SSA). Despite the utility of the electrocardiogram (ECG) in screening for CVD, there is limited data regarding longitudinal ECG changes among PWH in SSA. In this study, we aimed to describe ECG changes over a 6-month period in a cohort of PWH in northern Tanzania. Between September 2020 and March 2021, adult PWH were recruited from Majengo HIV Care and Treatment Clinic (MCTC) in Moshi, Tanzania. Trained research assistants surveyed participants and obtained a baseline ECG. Participants then returned to MCTC for a 6-month follow-up, where another ECG was obtained. Two independent physician adjudicators interpreted baseline and follow-up ECGs for rhythm, left ventricular hypertrophy (LVH), bundle branch blocks, ST-segment changes, and T-wave inversion, using standardized criteria. New ECG abnormalities were defined as those that were absent in a patient's baseline ECG but present in their 6-month follow-up ECG. Of 500 enrolled participants, 476 (95.2%) completed follow-up. The mean (± SD) age of participants was 45.7 (± 11.0) years, 351 (73.7%) were female, and 495 (99.8%) were taking antiretroviral therapy. At baseline, 248 (52.1%) participants had one or more ECG abnormalities, the most common of which were LVH (n = 108, 22.7%) and T-wave inversion (n = 89, 18.7%). At six months, 112 (23.5%) participants developed new ECG abnormalities, including 40 (8.0%) cases of new T-wave inversion, 22 (4.6%) cases of new LVH, 12 (2.5%) cases of new ST elevation, and 11 (2.3%) cases of new prolonged QTc. Therefore, new ECG changes were common over a relatively short 6-month period, which suggests that subclinical CVD may develop rapidly in PWH in Tanzania. These data highlight the need for additional studies on CVD in PWH in SSA and the importance of routine CVD screening in this high-risk population.

Robotic Optical Coherence Tomography Retinal Imaging for Emergency Department Patients: A Pilot Study for Emergency Physicians' Diagnostic Performance

STUDY OBJECTIVE

To evaluate the diagnostic performance of emergency physicians' interpretation of robotically acquired retinal optical coherence tomography images for detecting posterior eye abnormalities in patients seen in the emergency department (ED).

METHODS

Adult patients presenting to Duke University Hospital emergency department from November 2020 through October 2021 with acute visual changes, headache, or focal neurologic deficit(s) who received an ophthalmology consultation were enrolled in this pilot study. Emergency physicians provided standard clinical care, including direct ophthalmoscopy, at their discretion. Retinal optical coherence tomography images of these patients were obtained with a robotic, semi-autonomous optical coherence tomography system. We compared the detection of abnormalities in optical coherence tomography images by emergency physicians with a reference standard, a combination of ophthalmology consultation diagnosis and retina specialist optical coherence tomography review.

RESULTS

Nine emergency physicians reviewed the optical coherence tomography images of 72 eyes from 38 patients. Based on the reference standard, 33 (46%) eyes were normal, 16 (22%) had at least 1 urgent/emergency abnormality, and the remaining 23 (32%) had at least 1 nonurgent abnormality. Emergency physicians' optical coherence tomography interpretation had 69% (95% confidence interval [CI], 49% to 89%) sensitivity for any abnormality, 100% (95% CI, 79% to 100%) sensitivity for urgent/emergency abnormalities, 48% (95% CI, 28% to 68%) sensitivity for nonurgent abnormalities, and 64% (95% CI, 44% to 84%) overall specificity. In contrast, emergency physicians providing standard clinical care did not detect any abnormality with direct ophthalmoscopy.

CONCLUSION

Robotic, semi-autonomous optical coherence tomography enabled ocular imaging of emergency department patients with a broad range of posterior eye abnormalities. In addition, emergency provider optical coherence tomography interpretation was more sensitive than direct ophthalmoscopy for any abnormalities, urgent/emergency abnormalities, and nonurgent abnormalities in this pilot study with a small sample of patients and emergency physicians.

Six-month blood pressure and glucose control among HIV-infected adults with elevated blood pressure and hyperglycemia in northern Tanzania: A prospective observational study

BACKGROUND

People with HIV in sub-Saharan Africa are increasingly developing age-related comorbidities. The purpose of this prospective observational study was to describe 6-month outcomes among Tanzanians with HIV and elevated blood pressure or hyperglycemia under current care pathways.

METHODS

Adults presenting for routine HIV care were enrolled and underwent blood pressure and blood glucose measurements. Participants with abnormal blood pressure or glucose were referred for further care, as per current guidelines. Participants' blood pressure and point-of-care glucose were re-evaluated during their 6-month follow-up visit. Elevated blood pressure was defined as systolic ≥140 mmHg or diastolic ≥90 mmHg. Hyperglycemia was defined as fasting glucose ≥126 mg/dl or random glucose ≥200 mg/dl. An electrocardiogram was obtained at enrollment and at follow-up. Interim myocardial infarction and interim myocardial ischemia were defined as new pathologic Q waves and new T-wave inversions, respectively.

RESULTS

Of 500 participants, 155 had elevated blood pressure and 17 had hyperglycemia at enrolment. At 6-month follow-up, 7 (4.6%) of 155 participants with elevated blood pressure reported current use of an anti-hypertensive medication, 100 (66.2%) had persistent elevated blood pressure, 12 (7.9%) developed interim myocardial infarction, and 13 (8.6%) developed interim myocardial ischemia. Among 17 participants with hyperglycemia, 9 (56%) had persistent hyperglycemia at 6 months and 2 (12.5%) reported current use of an anti-hyperglycemic medication.

CONCLUSIONS

Interventions are needed to improve non-communicable disease care pathways among Tanzanians with HIV.

Outcomes in ED patients with non‐specific ECG findings and low high‐sensitivity troponin

Background

Although some emergency department risk stratification tools consider non‐specific ECG findings as an aid in disposition decisions, their clinical value in patients with an initially low high‐sensitivity cardiac troponin I (hsTnI) is unclear.

Objective

Our purpose was to determine if non‐specific ECG (ns‐ECG) findings are associated with 30‐day major adverse cardiac events (MACE) in ED patients presenting with suspected acute coronary syndromes (ACS) who have a low initial hsTnI.

Methods

Using the prospective Siemens Atellica hsTnI Food and Drug Administration submission observational database, we conducted a retrospective cohort study of the association between ns‐ECG findings (defined as left bundle branch block [LBBB], ST depression [STD], or T‐wave inversions [TWI]) and 30‐day MACE (death, myocardial infarction, heart failure hospitalization, or coronary revascularization). Eligible patients presented with suspected ACS to one of 29 US EDs from April 2015 to April 2016, had stable vital signs, a blood sample for hsTnI (Siemen's Atellica, Siemens Healthineers, Inc, Malvern, PA) obtained at 1, 3, and 6 hours after ED presentation, and were followed for 30 days. The relationship between 30‐day outcome, initial hsTnI, and ns‐ECG was evaluated using chi‐square testing.

Results

Of 2676 enrolled, 1313 patients met the inclusion criteria and are included in the analysis. Median (interquartile range) age was 62 years (54, 72), 54% were male, with 56% white, and 39% African American. Median (interquartile range) times from symptom onset to presentation and presentation to specimen collection were 92 (0, 216) and 146 (117, 177) minutes, respectively. The most common presenting symptoms were chest pain (84%), followed by dyspnea (9%). ECG findings were categorized as T‐wave inversion or non‐specific T wave changes (42%), ST depression ns‐ECG ST changes (16%), or LBBB (2%). Thirty‐day MACE occurred in 72 (5.5%) patients, with coronary revascularization (35 patients, 2.7%) and heart failure (25 patients, 1.9%) being the most frequent outcomes. In patients with an initial hsTnI below the limit of quantitation (LOQ) of 2.5 ng/L (n = 449), there was no association between ns‐ECG changes and 30‐day MACE (P = 0.42). If the hsTnI was ≥LOQ (2.5 ng/L), there were increased rates of 30‐day MACE and ns‐ECG findings (P = 0.01).

Conclusion

In ED suspected ACS patients without unstable vital signs, and an initial hsTnI less than the LOQ (2.5 ng/L), ns‐ECG findings are not associated with 30‐day major adverse cardiac events. The use of ns‐ECG findings in ACS disposition should be considered in the context of hsTnI levels.

Predictors of Stress-Delta High-Sensitivity Troponin T in Emergency Department Patients Undergoing Stress Testing

Background and objective

Elevations in high-sensitivity troponin T (hs-TnT) are frequently observed following extreme physical exercise. In light of this, we sought to determine whether specific clinical characteristics are associated with this phenomenon in patients undergoing cardiac exercise tolerance testing (ETT).

Methods

We conducted a retrospective analysis of a prospectively collected biospecimen repository of 257 patients undergoing a stress echocardiogram for possible acute coronary syndrome (ACS). Ischemic electrocardiogram (ECG) changes during ETT and the presence or absence of ischemia on imaging were determined by a board-licensed cardiologist. N-terminal pro-brain natriuretic peptide (NT-proBNP) and hs-TnT assays were obtained immediately before and two hours following ETT. We developed linear regression models including several clinical characteristics to predict two-hour stress-delta hs-TnT. Variable selection was performed using the least absolute shrinkage and selection operator (LASSO).

Results

The mean age of the patients was 52 years [standard deviation (SD): 11.4]; 125 (48.6%) of them were men, and 88 (34.2%) were African-American. Twenty-two patients (8.6%) had ischemia evident on echocardiography, and 31 (12.1%) had ischemic ECG changes during exercise. The mean baseline hs-TnT was 5.6 ng/L (SD: 6.4) and the mean two-hour hs-TnT was 7.1 ng/L (SD: 10.2). Age and ischemic ECG changes were associated with two-hour stress-delta hs-TnT values.

Conclusions

Based on our findings, ischemic changes in stress ECG and age were associated with an increase in hs-TnT levels following exercise during a stress echo.

Stress-Delta B-Type Natriuretic Peptide Does Not Exclude ACS in the ED

BACKGROUND

There are many detectable changes in circulating biomarkers in the setting of myocardial ischemia. We hypothesize that there are associated changes in circulating B-type natriuretic peptide (BNP) level after stress-induced myocardial ischemia, which can be used for emergency department (ED) acute coronary syndrome (ACS) risk stratification.

METHODS

In a prospective study, we enrolled 340 patients over the age of 30 receiving an exercise echocardiography stress test in an ED observational unit for suspected ACS. We collected blood samples at baseline and at 2 and 4 h post-stress test, measuring the relative and absolute changes (stress-delta) in plasma BNP concentrations. In addition, patients were contacted at 90 days and at 1 year posttest for a follow-up. We calculated the diagnostic test characteristics of stress-delta BNP for a composite outcome of ischemic imaging on stress echocardiogram, nonelective percutaneous coronary intervention, coronary artery bypass graft surgery, subsequent acute myocardial infarction, or cardiac death at 1 year via a logistic regression. We analyzed the 2-h BNP concentrations using an ANOVA model to adjust for the baseline BNP level.

RESULTS

Baseline and 2-h post-stress BNP were both higher in the positive outcome group, but the stress-delta BNP was not. Stress-delta BNP had a sensitivity and specificity, respectively, of 53% and 76% at 2 h and 67% and 68% at 4 h. It was noted that patients with the composite outcome had a higher baseline BNP level.

CONCLUSIONS

BNP stress-deltas are poor diagnostic means for ACS risk stratification, but resting BNP remains a promising prognostic tool for ED patients with suspected ACS.

A precision medicine approach to stress testing using metabolomics and microribonucleic acids

Both transcriptomics and metabolomics hold promise for identifying acute coronary syndrome (ACS) but they have not been used in combination, nor have dynamic changes in levels been assessed as a diagnostic tool. We assessed integrated analysis of peripheral blood miRNA and metabolite analytes to distinguish patients with myocardial ischemia on cardiac stress testing. We isolated and quantified miRNA and metabolites before and after stress testing from seven patients with myocardial ischemia and 1:1 matched controls. The combined miRNA and metabolomic data were analyzed jointly in a supervised, dimension-reducing discriminant analysis. We implemented a baseline model (T0) and a stress-delta model. This novel integrative analysis of the baseline levels of metabolites and miRNA expression showed modest performance for distinguishing cases from controls. The stress-delta model showed worse performance. This pilot study shows potential for an integrated precision medicine approach to cardiac stress testing.

Sepsis with liver dysfunction and coagulopathy predicts an inflammatory pattern of macrophage activation

Background

Interleukin-1 receptor antagonists can reduce mortality in septic shock patients with hepatobiliary dysfunction and disseminated intravascular coagulation (HBD + DIC), an organ failure pattern with inflammatory features consistent with macrophage activation. Identification of clinical phenotypes in sepsis may allow for improved care. We aim to describe the occurrence of HBD + DIC in a contemporary cohort of patients with sepsis and determine the association of this phenotype with known macrophage activation syndrome (MAS) biomarkers and mortality. We performed a retrospective nested case–control study in adult septic shock patients with concurrent HBD + DIC and an equal number of age-matched controls, with comparative analyses of all-cause mortality and circulating biomarkers between the groups. Multiple logistic regression explored the effect of HBD + DIC on mortality and the discriminatory power of the measured biomarkers for HBD + DIC and mortality.

Results

Six percent of septic shock patients (n = 82/1341) had HBD + DIC, which was an independent risk factor for 90-day mortality (OR = 3.1, 95% CI 1.4–7.5, p = 0.008). Relative to sepsis controls, the HBD + DIC cohort had increased levels of 21 of the 26 biomarkers related to macrophage activation (p < 0.05). This panel was predictive of both HBD + DIC (sensitivity = 82%, specificity = 84%) and mortality (sensitivity = 92%, specificity = 90%).

Conclusion

The HBD + DIC phenotype identified patients with high mortality and a molecular signature resembling that of MAS. These observations suggest trials of MAS-directed therapies are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40635-022-00433-y.

The prevalence, management, and thirty-day outcomes of symptomatic atrial fibrillation in a Tanzanian emergency department

Introduction

Data describing atrial fibrillation (AF) care in emergency centres (ECs) in sub-Saharan Africa is lacking. We sought to describe the prevalence and outcomes of AF in a Tanzanian EC.

Methods

In a prospective, observational study, adults presenting with chest pain or shortness of breath to a Tanzanian EC were enrolled from January through October 2019. Participants underwent electrocardiogram testing which were reviewed by two independent physician judges to determine presence of AF. Participants were asked about their medical history and medication use at enrollment, and a follow-up questionnaire was administered via telephone thirty days later to assess mortality, interim stroke, and medication use.

Results

Of 681 enrolled patients, 53 (7.8%) had AF. The mean age of participants with AF was 68.1, with a standard deviation (sd) of 21.1 years, and 23 of the 53 (43.4%) being male. On presentation, none of the participants found to have AF reported a previous history of AF. The median CHADS-VASC score among participants was 4 with an interquartile range (IQR) of 2-4. No participants were taking an anticoagulant at baseline. On index presentation, 49 (92.5%) participants with AF were hospitalised with 52 (98.1%) participants completing 30-day follow-up. 18 (34%) participants died, and 5 (9.6%) suffered a stroke. Of the surviving 31 participants with AF and a CHADS-VASC score ≥ 2, none were taking other anti-coagulants at 30 days. Compared to participants without AF, participants with AF were more likely to be hospitalised (OR 5.25, 95% CI 2.10-17.95, p < 0.001), more likely to die within thirty days (OR 1.93, 95% CI 1.03-3.50, p = 0.031), and more likely to suffer a stroke within thirty days (OR 5.91, 95% CI 1.76-17.28, p < 0.001).

Discussion

AF is common in a Tanzanian EC, with thirty-day mortality being high, but use of evidence-based therapies is rare. There is an opportunity to improve AF care and outcomes in Tanzania.

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In a Tanzanian emergency centre, atrial fibrillation was common but patient awareness of their condition was low

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Use of anticoagulants among patients with atrial fibrillation was rare both before and after hospital presentation

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Following hospital presentation, thirty-day mortality and stroke rates among patients with atrial fibrillation were high

Risk stratification with video capsule endoscopy leads to fewer hospital admissions in emergency department patients with low-risk to moderate-risk upper gastrointestinal bleed: A multicenter clinical trial

OBJECTIVE

In US emergency departments (EDs), the physician has limited ability to evaluate for common and serious conditions of the gastrointestinal (GI) mucosa such as a bleeding peptic ulcer. Although many bleeding lesions are self-limited, the majority of these patients require emergency hospitalization for upper endoscopy (EGD). We conducted a clinical trial to determine if ED risk stratification with video capsule endoscopy (VCE) reduces hospitalization rates for low-risk to moderate-risk patients with suspected upper GI bleeding.

METHODS

We conducted a randomized controlled trial at 3 urban academic EDs. Inclusion criteria included signs of upper GI bleeding and a Glasgow Blatchford score <6. Patients were randomly assigned to 1 of the following 2 treatment arms: (1) an experimental arm that included VCE risk stratification and brief ED observation versus (2) a standard care arm that included admission for inpatient EGD. The primary outcome was hospital admission. Patients were followed for 7 and 30 days to assess for rebleeding events and revisits to the hospital.

RESULTS

The trial was terminated early as a result of low accrual. The trial was also terminated early because of a need to repurpose all staff to respond to the coronavirus disease 2019 pandemic. A total of 24 patients were enrolled in the study. In the experimental group, 2/11 (18.2%) patients were admitted to the hospital, and in the standard of care group, 10/13 (76.9%) patients were admitted to the hospital (P = 0.012). There was no difference in safety on day 7 and day 30 after the index ED visit.

CONCLUSIONS

VCE is a potential strategy to decrease admissions for upper GI bleeding, though further study with a larger cohort is required before this approach can be recommended.

United States Emergency Department Use of Medications with Pharmacogenetic Recommendations

Introduction

Emergency departments (ED) use many medications with a range of therapeutic efficacy and potential significant side effects, and many medications have dosage adjustment recommendations based on the patient’s specific genotype. How frequently medications with such pharmaco-genetic recommendations are used in United States (US) EDs has not been studied.

Methods

We conducted a cross-sectional analysis of the 2010–2015 National Hospital Ambulatory Medical Care Survey (NHAMCS). We reported the proportion of ED visits in which at least one medication with Clinical Pharmacogenetics Implementation Consortium (CPIC) recommendation of Level A or B evidence was ordered. Secondary comparisons included distributions and 95% confidence intervals of age, gender, race/ethnicity, ED disposition, geographical region, immediacy, and insurance status between all ED visits and those involving a CPIC medication.

Results

From 165,155 entries representing 805,726,000 US ED visits in the 2010–2015 NHAMCS, 148,243,000 ED visits (18.4%) led to orders of CPIC medications. The most common CPIC medication was tramadol (6.3%). Visits involving CPIC medications had higher proportions of patients who were female, had private insurance and self-pay, and were discharged from the ED. They also involved lower proportions of patients with Medicare and Medicaid.

Conclusion

Almost one fifth of US ED visits involve a medication with a pharmacogenetic recommendation that may impact the efficacy and toxicity for individual patients. While direct application of genotyping is still in development, it is important for emergency care providers to understand and support this technology given its potential to improve individualized, patient-centered care.

Machine Learning and Precision Medicine in Emergency Medicine: The Basics

As machine learning (ML) and precision medicine become more readily available and used in practice, emergency physicians must understand the potential advantages and limitations of the technology. This narrative review focuses on the key components of machine learning, artificial intelligence, and precision medicine in emergency medicine (EM). Based on the content expertise, we identified articles from EM literature. The authors provided a narrative summary of each piece of literature. Next, the authors provided an introduction of the concepts of ML, artificial intelligence as an extension of ML, and precision medicine. This was followed by concrete examples of their applications in practice and research. Subsequently, we shared our thoughts on how to consume the existing research in these subjects and conduct high-quality research for academic emergency medicine. We foresee that the EM community will continue to adapt machine learning, artificial intelligence, and precision medicine in research and practice. We described several key components using our expertise.

Thirty-day outcomes and predictors of mortality following acute myocardial infarction in northern Tanzania: A prospective observational cohort study

OBJECTIVE

There is a rising burden of myocardial infarction (MI) within sub-Saharan Africa. Prospective studies of detailed MI outcomes in the region are lacking.

METHODS

Adult patients with confirmed MI from a prospective surveillance study in northern Tanzania were enrolled in a longitudinal cohort study after baseline health history, medication use, and sociodemographic data were obtained. Thirty days following hospital presentation, symptom status, rehospitalizations, medication use, and mortality were assessed via telephone or in-person interviews using a standardized follow-up questionnaire. Multivariate logistic regression was performed to identify baseline predictors of thirty-day mortality.

RESULTS

Thirty-day follow-up was achieved for 150 (98.7%) of 152 enrolled participants. Of these, 85 (56.7%) survived to thirty-day follow-up. Of the surviving participants, 71 (83.5%) reported persistent anginal symptoms, four (4.7%) reported taking aspirin regularly, seven (8.2%) were able to identify MI as the reason for their hospitalization, and 17 (20.0%) had unscheduled rehospitalizations. Self-reported history of diabetes at baseline (OR 0.32, 95% CI 0.10-0.89, p = 0.04), self-reported history of hypertension at baseline (OR 0.34, 95% CI 0.15-0.74, p = 0.01), and antiplatelet use at initial presentation (OR 0.19, 95% CI 0.04-0.65, p = 0.02) were all associated with lower odds of thirty-day mortality.

CONCLUSIONS

In northern Tanzania, thirty-day outcomes following acute MI are poor, and mortality is associated with self-awareness of comorbidities and medication usage. Further investigation is needed to develop interventions to improve care and outcomes of MI in Tanzania.

Sex-related differences in D-dimer levels for venous thromboembolism screening

BACKGROUND

D-dimer is generally considered positive above 0.5 mg/L irrespective of sex. However, women have been shown to be more likely to have a positive D-dimer after controlling for other factors. Thus, differences may exist between males and females for using D-dimer as a marker of venous thromboembolic (VTE) disease. We hypothesized that the accuracy of D-dimer tests may be enhanced by using appropriate cutoff values that reflect sex-related differences in D-dimer levels.

METHODS

This research is a secondary analysis of a multicenter, international, prospective, observational study of adult (18+ years) patients suspected of VTE, with low-to-intermediate pretest probability based on Wells criteria ≤ 6 for pulmonary embolism (PE) and ≤ 2 for deep vein thrombosis (DVT). VTE diagnoses were based on computed tomography, ventilation perfusion scanning, or venous ultrasound. D-dimer levels were tested for statistical difference across groups stratified by sex and diagnosis. Multivariable regression was used to investigate sex as a predictor of diagnosis. Sex-specific optimal D-dimer thresholds for PE and DVT were calculated from receiver operating characteristic analyses. A Youden threshold (D-dimer level coinciding with the maximum of sensitivity plus specificity) and a cutoff corresponding to 95% sensitivity were calculated. Statistical difference for cutoffs was tested via 95% confidence intervals from 2,000 bootstrapped samples.

RESULTS

We included 3,586 subjects for analysis, of whom 61% were female. Race demographics were 63% White, 27% Black/African American, and 6% Hispanic. In the suspected PE cohort, 6% were diagnosed with PE, while in the suspected DVT cohort, 11% were diagnosed with DVT. D-dimer levels were significantly higher in males than females for the PE-positive group and the DVT-negative group, but males had significantly lower D-dimer levels than females in the PE-negative group. Regression models showed male sex as a significant positive predictor of DVT diagnosis, controlling for D-dimer levels. The Youden thresholds for PE patients were 0.97 (95% CI = 0.64 to 1.79) mg/L and 1.45 (95% CI = 1.36 to 1.95) mg/L for females and males, respectively; 95% sensitivity cutoffs for this group were 0.64 (95% CI = 0.20 to 0.89) and 0.55 (95% CI = 0.29 to 1.61). For DVT, the Youden thresholds were 0.98 (95% CI = 0.84 to 1.56) mg/L for females and 1.25 (95% CI = 0.65 to 3.33) mg/L for males with 95% sensitivity cutoffs of 0.33 (95% CI = 0.2 to 0.61) and 0.32 (95% CI = 0.18 to 0.7), respectively.

CONCLUSION

Differences in D-dimer levels between males and females are diagnosis specific; however, there was no significant difference in optimal cutoff values for excluding PE and DVT between the sexes.

Incidence of Acute Myocardial Infarction in Northern Tanzania: A Modeling Approach Within a Prospective Observational Study

Background

Rigorous incidence data for acute myocardial infarction (AMI) in sub‐Saharan Africa are lacking. Consequently, modeling studies based on limited data have suggested that the burden of AMI and AMI‐associated mortality in sub‐Saharan Africa is lower than in other world regions.

Methods and Results

We estimated the incidence of AMI in northern Tanzania in 2019 by integrating data from a prospective surveillance study (681 participants) and a community survey of healthcare‐seeking behavior (718 participants). In the surveillance study, adults presenting to an emergency department with chest pain or shortness of breath were screened for AMI with ECG and troponin testing. AMI was defined by the Fourth Universal Definition of AMI criteria. Mortality was assessed 30 days following enrollment via in‐person or telephone interviews. In the cluster‐based community survey, adults in northern Tanzania were asked where they would present for chest pain or shortness of breath. Multipliers were applied to account for AMI cases that would have been missed by our surveillance methods. The estimated annual incidence of AMI was 172 (207 among men and 139 among women) cases per 100 000 people. The age‐standardized annual incidence was 211 (263 among men and 170 among women) per 100 000 people. The estimated annual incidence of AMI‐associated mortality was 87 deaths per 100 000 people, and the age‐standardized annual incidence was 102 deaths per 100 000 people.

Conclusions

The incidence of AMI and AMI‐associated mortality in northern Tanzania is much higher than previously estimated and similar to that observed in high‐income countries.

Immune response profiling in patients with traumatic injuries associated with alcohol ingestion

Traumatic injuries afflict more than 5 million people globally every year. Current and past animal research has demonstrated association among alcohol, trauma, and impaired immune function, whereas human registries have shown association between alcohol and morbidity as well as mortality. The purpose of this study is to elucidate the immune interactions with alcohol in traumatically injured patients. We prospectively enrolled 379 patients after trauma at three medical centers in the Surgical Critical Care Initiative. Plasma was analyzed using Luminex for up to 35 different cytokines. Collected samples were grouped by patients with detectable plasma alcohol levels versus those without. Univariate testing determined differences in analytes between groups. We built Bayesian belief networks with multiple minimum descriptive lengths to compare the two groups. All 379 patient samples were analyzed. Two hundred eighty-two (74.4%) patients were men, and 143 (37.7%) were White. Patients had a median intensive care unit length of stay (LOS) of 5.8 days and hospital LOS of 12 days. Using single variate analyses, eight different cytokines were differentially associated with alcohol. Cytokines IL-12 and IL-6 were important nodes in both models and IL-10 was a prominent node in the nonalcohol model. This study found select immune function differed between traumatically injured patients with measurable serum alcohol levels as compared with those without. Traumatically injured patients with positive blood alcohol content appear less able to inhibit inflammatory stress. Alcohol appears to suppress pro-inflammatory IL-12 and IL-6, whereas patients without alcohol have greater levels of anti-inflammatory IL-10 expressed at injury and may better regulate anti-inflammatory pathways. Future studies should determine the relationship with these markers with clinically oriented outcomes.

Association of a Network of Immunologic Response and Clinical Features With the Functional Recovery From Crotalinae Snakebite Envenoming

Background

The immunologic pathways activated during snakebite envenoming (SBE) are poorly described, and their association with recovery is unclear. The immunologic response in SBE could inform a prognostic model to predict recovery. The purpose of this study was to develop pre- and post-antivenom prognostic models comprised of clinical features and immunologic cytokine data that are associated with recovery from SBE.

Materials and Methods

We performed a prospective cohort study in an academic medical center emergency department. We enrolled consecutive patients with Crotalinae SBE and obtained serum samples based on previously described criteria for the Surgical Critical Care Initiative (SC2i)(ClinicalTrials.gov Identifier: NCT02182180). We assessed a standard set of clinical variables and measured 35 unique cytokines using Luminex Cytokine 35-Plex Human Panel pre- and post-antivenom administration. The Patient-Specific Functional Scale (PSFS), a well-validated patient-reported outcome of functional recovery, was assessed at 0, 7, 14, 21 and 28 days and the area under the patient curve (PSFS AUPC) determined. We performed Bayesian Belief Network (BBN) modeling to represent relationships with a diagram composed of nodes and arcs. Each node represents a cytokine or clinical feature and each arc represents a joint-probability distribution (JPD).

Results

Twenty-eight SBE patients were enrolled. Preliminary results from 24 patients with clinical data, 9 patients with pre-antivenom and 11 patients with post-antivenom cytokine data are presented. The group was mostly female (82%) with a mean age of 38.1 (SD ± 9.8) years. In the pre-antivenom model, the variables most closely associated with the PSFS AUPC are predominantly clinical features. In the post-antivenom model, cytokines are more fully incorporated into the model. The variables most closely associated with the PSFS AUPC are age, antihistamines, white blood cell count (WBC), HGF, CCL5 and VEGF. The most influential variables are age, antihistamines and EGF. Both the pre- and post-antivenom models perform well with AUCs of 0.87 and 0.90 respectively.

Discussion

Pre- and post-antivenom networks of cytokines and clinical features were associated with functional recovery measured by the PSFS AUPC over 28 days. With additional data, we can identify prognostic models using immunologic and clinical variables to predict recovery from SBE.

A hypothetical implementation of 'Termination of Resuscitation' protocol for out-of-hospital cardiac arrest

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A proportion of out of hospital cardiac arrests are associated with poor prognoses.

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Prolonged resuscitation on medically futile cases results in financial burden for the health system and distress for health care workers.

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‘Termination of Resuscitation’ protocols enable ceasing resuscitation efforts for certain cases.

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Successfully adopting a protocol over existing practices demonstrates fewer cases transported to hospital, fewer emergency treatments and fewer inpatient bed days used.

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The protocol can lead to reduced costs and fewer non-beneficial hospital admissions.

Background

Out-of-hospital cardiac arrests with negligible chance of survival are routinely transported to hospital and many are pronounced dead thereafter. This leads to some potentially avoidable costs. The ‘Termination of Resuscitation’ protocol allows paramedics to terminate resuscitation efforts onsite for medically futile cases. This study estimates the changes in frequency of costly events that might occur when the protocol is applied to out-of-hospital cardiac arrests, as compared to existing practice.

Methods

We used Singapore data from the Pan-Asian Resuscitation Outcomes Study, from 1 Jan 2014 to 31 Dec 2017. A Markov model was developed to summarise the events that would occur in two scenarios, existing practice and the implementation of a Termination of Resuscitation protocol. The model was evaluated for 10,000 hypothetical patients with a cycle duration of 30 days after having a cardiac arrest. Probabilistic sensitivity analysis accounted for uncertainties in the outcomes: number of urgent transports and emergency treatments, inpatient bed days, and total number of deaths.

Results

For every 10,000 patients, existing practice resulted in 1118 (95% Uncertainty Interval 1117 to 1119) additional urgent transports to hospital and subsequent emergency treatments. There were 93 (95% Uncertainty Interval 66 to 120) extra inpatient bed days used, and 3 fewer deaths (95% Uncertainty Interval 2 to 4) in comparison to using the protocol.

Conclusion

The findings provide some evidence for adopting the Termination of Resuscitation protocol. This policy could lead to a reduction in costs and non-beneficial hospital admissions, however there may be a small increase in the number of avoidable deaths.

A Method for Grouping Emergency Department Visits by Severity and Complexity

INTRODUCTION

Triage functions to quickly prioritize care and sort patients by anticipated resource needs. Despite widespread use of the Emergency Severity Index (ESI), there is still no universal standard for emergency department (ED) triage. Thus, it can be difficult to objectively assess national trends in ED acuity and resource requirements. We sought to derive an ESI from National Hospital Ambulatory Medical Care Survey (NHAMCS) survey items (NHAMCS-ESI) and to assess the performance of this index with respect to stratifying outcomes, including hospital admission, waiting times, and ED length of stay (LOS).

METHODS

We used data from the 2010-2015 NHAMCS, to create a measure of ED visit complexity based on variables within NHAMCS. We used NHAMCS data on chief complaint, vitals, resources used, interventions, and pain level to group ED visits into five levels of acuity using a stepwise algorithm that mirrored ESI. In addition, we examined associations of NHAMCS-ESI with typical indicators of acuity such as waiting time, LOS, and disposition. The NHAMCS-ESI categorization was also compared against the "immediacy" variable across all of these outcomes. Visit counts used weighted scores to estimate national levels of ED visits.

RESULTS

The NHAMCS ED visits represent an estimated 805,726,000 ED visits over this time period. NHAMCS-ESI categorized visits somewhat evenly, with most visits (42.5%) categorized as a level 3. The categorization pattern is distinct from that of the "immediacy" variable within NHAMCS. Of admitted patients, 89% were categorized as NHAMCS-ESI level 2-3. Median ED waiting times increased as NHAMCS-ESI levels decreased in acuity (from approximately 14 minutes to 25 minutes). Median LOS decreased as NHAMCS-ESI decreased from almost 200 minutes for level 1 patients to nearly 80 minutes for level 5 patients.

CONCLUSION

We derived an objective tool to measure an ED visit's complexity and resource use. This tool can be validated and used to compare complexity of ED visits across hospitals and regions, and over time.

Acute myocardial infarction under-diagnosis and mortality in a Tanzanian emergency department: A prospective observational study

BACKGROUND

Growing evidence suggests that under-diagnosis of acute myocardial infarction (AMI) may be common in sub-Saharan Africa. Prospective studies of routine AMI screening among patients presenting to emergency departments in sub-Saharan Africa are lacking. Our objective was to determine the prevalence of AMI among patients in a Tanzanian emergency department.

METHODS

In a prospective observational study, consecutive adult patients presenting with chest pain or shortness of breath to a referral hospital emergency department in northern Tanzania were enrolled. Electrocardiogram (ECG) and troponin testing were performed for all participants to diagnose AMI types according to the Fourth Universal Definition. All ECGs were interpreted by two independent physician judges. ECGs suggesting ST-elevation myocardial infarction (STEMI) were further reviewed by additional judges. Mortality was assessed 30 days following enrollment.

RESULTS

Of 681 enrolled participants, 152 (22.3%) had AMI, including 61 STEMIs and 91 non-STEMIS (NSTEMIs). Of AMI patients, 91 (59.9%) were male, mean (SD) age was 61.2 (18.5) years, and mean (SD) duration of symptoms prior to presentation was 6.6 (12.2) days. In the emergency department, 35 (23.0%) AMI patients received aspirin and none received thrombolytics. Of 150 (98.7%) AMI patients completing 30-day follow-up, 65 (43.3%) had died.

CONCLUSIONS

In a northern Tanzanian emergency department, AMI is common, rarely treated with evidence-based therapies, and associated with high mortality. Interventions are needed to improve AMI diagnosis, care, and outcomes.

Video capsule endoscopy for upper gastrointestinal hemorrhage in the emergency department: A systematic review and meta-analysis

OBJECTIVE

The assessment of the severity of upper gastrointestinal hemorrhage in emergency department (ED) patients is difficult to assess with commonly available diagnostic tools. Small studies have shown that video capsule endoscopy (VCE) is a promising risk-stratification method and may be better than current clinical decision rules such as the Rockall score and the Glasgow Blatchford score. This review aims to assess the accuracy of VCE to detect active upper gastrointestinal hemorrhage compared to a reference standard.

METHODS

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology was used to perform a review of studies that have measured the diagnostic accuracy of VCE. Studies were included if they measured ED use of VCE for upper GI hemorrhage as compared to a reference standard of an esophagogastroduodenoscopy (EGD). A meta-analysis was performed on select patients using a fixed effects and random-effects model to determine the primary outcome of diagnostic test accuracy.

RESULTS

40 studies were screened for eligibility and five studies representing 193 patients met the inclusion and exclusion criteria. All patients received both a VCE and an EGD. The sensitivity and specificity of VCE were 0.724 and 0.748, respectively. The diagnostic odds ratio was 6.29 (95% CI: 3.23-12.25) and the summary receiver operating characteristic curve was 0.782.

CONCLUSIONS

VCE demonstrated high accuracy for detecting upper GI hemorrhage in this meta-analysis of existing studies. In light of the potential advantages of VCE in the ED, further research is warranted to further establish its role.

Stress-delta B-type Natriuretic Peptide Levels as a Test for Inducible Myocardial Ischemia: A Systematic Review and Meta-Analysis

Background Cardiac ischemia induces myocardial dysfunction and ventricular wall stretch, which causes the release of B-type natriuretic peptide (BNP) into the bloodstream. However, it is unclear whether inducible ischemia produces a significant change in BNP levels ("stress delta-BNP"). The objective of this study was to determine the utility of stress-delta BNP levels and its precursor NT-proBNP for detecting inducible myocardial ischemia during cardiac stress testing. Methods We conducted a systematic review and meta-analysis. We searched PubMed, EMBASE, Web of Science, Cumulative Index of Nursing and Allied Health Literature (CINAHL), and Ovid. Studies examining the changes in levels of BNP and its precursor, N-terminal pro-B-type natriuretic peptide (NT-proBNP), after an exercise cardiac stress test were included. Two reviewers independently analyzed titles and abstracts. Abstracts that did not provide enough information regarding eligibility criteria were kept for full-text evaluation. The same two reviewers also performed data extraction for analyses. Any disagreement was resolved by a consensus and, if it persisted, by a third reviewer adjudication. We report the median and mean values in studies in the order of sample size. Results A total of 15 studies met the inclusion criteria. Nine studies reported results in medians and six studies reported results in means. Of the nine studies, five assessed BNP alone, three assessed NT-proBNP, and one assessed both. Due to the non-normal distribution of results in these studies, they could not be meta-analyzed. Of the six studies that reported results in means, three assessed BNP and three assessed NT-proBNP. The standardized difference between normal and ischemic patients' stress-delta BNP values was -0.39 (95% confidence interval (CI): -0.61; -0.17) in a fixed-effects model and -0.73 (95% CI: -1.72; 0.28) in the random-effects model with high heterogeneity (I^2 = 94%, Q test P = 0.001). For NT-proBNP, the meta-analysis model showed no significant difference between the stress-delta test for ischemic and normal patients (standardized mean difference (SMD): -0.02, 95% CI: -0.31; 0.28). Patients without inducible ischemia appeared to have a lower baseline BNP and NT-proBNP compared to patients with inducible ischemia by stress testing. Although some studies report higher stress-delta BNP in the ischemic group, this pattern was not seen consistently across studies. There was high heterogeneity across studies which was not robust to sensitivity analysis. A random-effects model failed to find statistically significant differences in stress-delta BNP or NT-proBNP. Conclusions We failed to find a relationship between stress-delta BNP or NT-proBNP and the presence or absence of ischemia. This may be due to high heterogeneity in the underlying studies.

The 99th percentile upper reference limit for the 5th generation cardiac troponin T assay in the United States

BACKGROUND

Determining diagnostic thresholds for cardiac troponin assays is key to interpreting their clinical performance. We describe the calculation of 99th percentile upper reference limits (URLs) for the Elecsys® Troponin T Gen 5 (TnT Gen 5) assay.

METHODS

Plasma and serum samples from healthy US participants were prospectively evaluated using TnT Gen 5 Short Turn Around Time and 18-min assays on cobas e 411 and cobas e 601 analyzers (Roche Diagnostics); with, up to 8 TnT Gen 5 results per participant.

RESULTS

A total of 10,402 TnT Gen 5 results from 1301 participants were included (50.4% female). Across 9 calculation methods, overall 99th percentile URL was 19.2 ng/l (females, 13.5-13.6 ng/l; males, 21.4-22.2 ng/l). Across different sample/assay/analyzer combinations, overall 99th percentile URLs ranged from 18.4-20.2 ng/l. Median TnT Gen 5 results increased with age, were higher in males, and ranged from 3.0-3.7 ng/l across races/ethnicities and from 3.0-3.6 ng/l across body mass index (BMI) classes. Applying additional exclusion criteria (N-terminal pro-brain natriuretic peptide, BMI and estimated glomerular filtration rate) resulted in lower 99th percentile URLs (overall, 16.9 ng/l; females, 11.8 ng/l; males, 18.5 ng/l).

CONCLUSION

Our findings facilitate the interpretation of TnT Gen 5 results in US clinical practice.

Duplicated or Ectopic Renal Collecting System in Two Adult Emergency Department Patients

BACKGROUND

Duplicated renal collecting system is a urological anomaly often found in pediatric patients. It is less commonly diagnosed in adulthood, particularly in a pregnant patient. Many point-of-care ultrasonography users may not be aware of this diagnosis, particularly in patients in the emergency department. It is important to recognize the duplicated system because in general, patients will often have hydronephrosis in only one renal pole rather than the entire kidney, which corresponds to an unequal renal function as documented on renal nuclear medicine functional scans. As a consequence, if the sonographer only identifies one ureter and incompletely visualizes the kidney, obstruction of one of the duplicated structures may be missed.

CASE REPORT

We report 2 cases of duplicated ureter in patients in the emergency department who present with flank pain and urinary symptoms. Both patients were adult females, one pregnant, with duplicated ureter and severe right upper pole hydroureteronephrosis. The first patient was admitted for intravenous antibiotic therapy for pyelonephritis in pregnancy. The second was discharged with oral antibiotics and urgent urologic follow-up. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Duplicated ureter should be considered in patients with recurrent urinary tract infections or enuresis. Point-of-care ultrasonography users should note the differential hydronephrosis between upper and lower renal poles and may visualize duplicate or ectopic ureteronephrosis or ureterocele. Patients should be prescribed prophylactic antibiotics and have urgent urologic follow-up because the untreated condition can lead to irreversible renal damage.

The burden of acute coronary syndrome, heart failure, and stroke among emergency department admissions in Tanzania: A retrospective observational study

Introduction

The prevalence of cardiovascular disease in sub-Saharan Africa is substantial and growing. Much remains to be learned about the relative burden of acute coronary syndrome (ACS), heart failure, and stroke on emergency departments and hospital admissions.

Methods

A retrospective chart review of admissions from September 2017 through March 2018 was conducted at the emergency department of a tertiary care center in northern Tanzania. Stroke admission volume was compared to previously published data from the same hospital and adjusted for population growth.

Results

Of 2418 adult admissions, heart failure and stroke were the two most common admission diagnoses, accounting for 294 (12.2%) and 204 (8.4%) admissions, respectively. ACS was uncommon, accounting for 9 (0.3%) admissions. Of patients admitted for heart failure, uncontrolled hypertension was the most commonly identified etiology of heart failure, cited in 124 (42.2%) cases. Ischemic heart disease was cited as the etiology in only 1 (0.3%) case. Adjusting for population growth, the annual volume of stroke admissions increased 70-fold in 43 years, from 2.9 admissions per 100,000 population in 1974 to 202.2 admissions per 100,000 in 2017.

Conclusions

The burden of heart failure and stroke on hospital admissions in Tanzania is substantial, and the volume of stroke admissions is rising precipitously. ACS is a rare diagnosis, and the distribution of cardiovascular disease phenotypes in Tanzania differs from what has been observed outside of Africa. Further research is needed to ascertain the reasons for these differences.

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In northern Tanzania, acute coronary syndrome is a rare admission diagnosis

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Heart failure and stroke are the most common admission diagnoses

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The burden of stroke admissions in this community is rising rapidly

Efficacy of High-Sensitivity Troponin T in Identifying Very-Low-Risk Patients With Possible Acute Coronary Syndrome

Importance

Physicians need information on how to use the first available high-sensitivity troponin (hsTnT) assay in the United States to identify patients at very low risk for 30-day adverse cardiac events (ACE).

Objective

To determine whether a negative hsTnT assay at 0 and 3 hours following emergency department presentation could identify patients at less than 1% risk of a 30-day ACE.

Design, Setting, and Participants

A prospective, observational study at 15 emergency departments in the United States between 2011 and 2015 that included individuals 21 years and older, presenting to the emergency department with suspected acute coronary syndrome. Of 1690 eligible individuals, 15 (no cardiac troponin T measurement) and 320 (missing a 0-hour or 3-hour sample) were excluded from the analyses.

Exposures

Serial hsTnT measurements (fifth-generation Roche Elecsys hsTnT assay).

Main Outcomes and Measures

Serial blood samples from each patient were collected after emergency department presentation (once identified as a potential patient with acute coronary syndrome) and 3 hours, 6 to 9 hours, and 12 to 24 hours later. Adverse cardiac events were defined as myocardial infarction, urgent revascularization, or death. The upper reference level for the hsTnT assay, defined as the 99th percentile, was established as 19 ng/L in a separate healthy US cohort. Patients were considered ruled out for acute myocardial infarction if their hsTnT level at 0 hours and 3 hours was less than the upper reference level. Gold standard diagnoses were determined by a clinical end point committee. Evaluation of assay clinical performance for acute myocardial infarction rule-out was prespecified; the hypothesis regarding 30-day ACE was formulated after data collection.

Results

In 1301 healthy volunteers (50.4% women; median age, 48 years), the upper reference level was 19 ng/L. In 1600 patients with suspected acute coronary syndrome (48.4% women; median age, 55 years), a single hsTnTlevel less than 6 ng/L at baseline had a negative predictive value for AMI of 99.4%. In 974 patients (77.1%) with both 0-hour and 3-hour hsTnT levels of 19 ng/L or less, the negative predictive value for 30-day ACE was 99.3% (95% CI, 99.1-99.6). Using sex-specific cutpoints, C statistics for women (0.952) and men (0.962) were similar for acute myocardial infarction.

Conclusions and Relevance

A single hsTnT level less than 6 ng/L was associated with a markedly decreased risk of AMI, while serial levels at 19 ng/L or less identified patients at less than 1% risk of 30-day ACE.

Damage- and pathogen-associated molecular patterns play differential roles in late mortality after critical illness

Multiple organ failure (MOF) is the leading cause of late mortality and morbidity in patients who are admitted to intensive care units (ICUs). However, there is an epidemiologic discrepancy in the mechanism of underlying immunologic derangement dependent on etiology between sepsis and trauma patients in MOF. We hypothesized that damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs), while both involved in the development of MOF, contribute differently to the systemic innate immune derangement and coagulopathic changes. We found that DAMPs not only produce weaker innate immune activation than counterpart PAMPs, but also induce less TLR signal desensitization, contribute to less innate immune cell death, and propagate more robust systemic coagulopathic effects than PAMPs. This differential contribution to MOF provides further insight into the contributing factors to late mortality in critically ill trauma and sepsis patients. These findings will help to better prognosticate patients at risk of MOF and may provide future therapeutic molecular targets in this disease process.

Pilot study of myocardial ischemia-induced metabolomic changes in emergency department patients undergoing stress testing

BACKGROUND

The heart is a metabolically active organ, and plasma acylcarnitines are associated with long-term risk for myocardial infarction. We hypothesized that myocardial ischemia from cardiac stress testing will produce dynamic changes in acylcarnitine and amino acid levels compared to levels seen in matched control patients with normal stress tests.

METHODS

We analyzed targeted metabolomic profiles in a pilot study of 20 case patients with inducible ischemia on stress testing from an existing prospectively collected repository of 357 consecutive patients presenting with symptoms of Acute Coronary Syndrome (ACS) in an Emergency Department (ED) observation unit between November 2012 and September 2014. We selected 20 controls matched on age, sex, and body-mass index (BMI). A peripheral blood sample was drawn <1 hour before stress testing and 2 hours after stress testing on each patient. We assayed 60 select acylcarnitines and amino acids by tandem mass spectrometry (MS/MS) using a Quattro Micro instrument (Waters Corporation, Milford, MA). Metabolite values were log transformed for skew. We then performed bivariable analysis for stress test outcome and both individual timepoint metabolite concentrations and stress-delta metabolite ratios (T2/T0). False discovery rates (FDR) were calculated for 60 metabolites while controlling for age, sex, and BMI. We built multivariable regularized linear models to predict stress test outcome from metabolomics data at times 0, 2 hours, and log ratio between these two. We used leave-one-out cross-validation to estimate the performance characteristics of the model.

RESULTS

Nine of our 20 case subjects were male. Cases' average age was 55.8, with an average BMI 29.5. Bivariable analysis identified 5 metabolites associated with positive stress tests (FDR < 0.2): alanine, C14:1-OH, C16:1, C18:2, C20:4. The multivariable regularized linear models built on T0 and T2 had Area Under the ROC Curve (AUC-ROC) between 0.5 and 0.55, however, the log(T2/T0) model yielded 0.625 AUC, with 65% sensitivity and 60% specificity. The top metabolites selected by the model were: Ala, Arg, C12-OH/C10-DC, C14:1-OH, C16:1, C18:2, C18:1, C20:4 and C18:1-DC.

CONCLUSIONS

Stress-delta metabolite analysis of patients undergoing stress testing is feasible. Future studies with a larger sample size are warranted.

Priorities to Overcome Barriers Impacting Data Science Application in Emergency Care Research

For a variety of reasons including cheap computing, widespread adoption of electronic medical records, digitalization of imaging and biosignals, and rapid development of novel technologies, the amount of health care data being collected, recorded, and stored is increasing at an exponential rate. Yet despite these advances, methods for the valid, efficient, and ethical utilization of these data remain underdeveloped. Emergency care research, in particular, poses several unique challenges in this rapidly evolving field. A group of content experts was recently convened to identify research priorities related to barriers to the application of data science to emergency care research. These recommendations included: 1) developing methods for cross-platform identification and linkage of patients; 2) creating central, deidentified, open-access databases; 3) improving methodologies for visualization and analysis of intensively sampled data; 4) developing methods to identify and standardize electronic medical record data quality; 5) improving and utilizing natural language processing; 6) developing and utilizing syndrome or complaint-based based taxonomies of disease; 7) developing practical and ethical framework to leverage electronic systems for controlled trials; 8) exploring technologies to help enable clinical trials in the emergency setting; and 9) training emergency care clinicians in data science and data scientists in emergency care medicine. The background, rationale, and conclusions of these recommendations are included in the present article.

Toll-like receptor activation as a biomarker in traumatically injured patients

BACKGROUND

Surgical insult and trauma have been shown to cause dysregulation of the immune and inflammatory responses. Interaction of damage-associated molecular patterns (DAMPs) with toll-like receptors (TLRs) initiates innate immune response and systemic inflammatory responses. Given that surgical patients produce high levels of circulating damage-associated molecular patterns, we hypothesized that plasma-activated TLR activity would be correlated to injury status and could be used to predict pathological conditions involving tissue injury.

METHODS

An observational study was performed using samples from a single-institution prospective tissue and data repository from a Level-1 trauma center. In vitro TLR 2, 3, 4, and 9 activation was determined in a TLR reporter assay after isolation of plasma from peripheral blood. We determined correlations between plasma-activated TLR activity and clinical course measures of severity.

RESULTS

Eighteen patients were enrolled (median Injury Severity Score 15 [interquartile range 10, 23.5]). Trauma resulted in significant elevation in circulation high mobility group box 1 as well as increase of plasma-activated TLR activation (2.8-5.4-fold) compared to healthy controls. There was no correlation between circulating high mobility group box 1 and trauma morbidity; however, the plasma-activated TLR activity was correlated with acute physiology and chronic health evaluation II scores (R square = 0.24-0.38, P < 0.05). Patients who received blood products demonstrated significant increases in the levels of plasma-activated TLRs 2, 3, 4, and 9 and had a trend toward developing systemic inflammatory response syndrome.

CONCLUSIONS

Further studies examining TLR modulation and signaling in surgical patients may assist in predictive risk modeling and reduction in morbidity and mortality.

Unexpected Cardiac MRI Findings in Patients Presenting to the Emergency Department for Possible Acute Coronary Syndrome

BACKGROUND

Stress cardiac magnetic resonance imaging (CMR) has become increasingly used in patients presenting to the emergency department (ED) with symptoms concerning for acute coronary syndrome (ACS). We hypothesized that CMR detects a number of alternative diagnoses (diagnoses other than ACS that could explain symptoms) and incidental findings in patients presenting to the ED for potential ACS.

METHODS

We prospectively enrolled adult patients who presented to an academic ED from 2011 to 2015 for possible ACS and subsequently had an adenosine stress perfusion CMR as part of their diagnostic evaluation. All medical charts were reviewed to verify accurate prospective data collection and to collect follow-up data.

RESULTS

A total of 391 patients were included. On stress CMR, abnormalities attributable to coronary artery disease (CAD) were found in 106 (27.1%) of patients. Previously undiagnosed moderate to severe valvular disease was the most common non-CAD cardiac finding, occurring in 20 (5.1%) cases. Other alternative diagnoses were rare with 7 cases of cardiomyopathy, 1 case of aortic aneurysm, 1 case of aortic dissection, 1 case of acute myocarditis, 3 cases of pericarditis, and 2 cases of moderate pleural effusion. Cardiac incidental findings were rare. Extracardiac incidental findings were found in 79 patients (20.2%). Only 18.6% of the patients recommended for follow-up imaging had this completed within 1 year after CMR.

CONCLUSIONS

This experience suggests that stress CMR is useful in not only diagnosing symptomatic CAD but also potentially important non-CAD-related disease. These factors may impact their use in ED-based ACS workups.

NHAMCS Validation of Emergency Severity Index as an Indicator of Emergency Department Resource Utilization

Introduction

Triage systems play a vital role in emergency department (ED) operations and can determine how well a given ED serves its local population. We sought to describe ED utilization patterns for different triage levels using the National Hospital Ambulatory Medical Care Survey (NHAMCS) database.

Methods

We conducted a multi-year secondary analysis of the NHAMCS database from 2009-2011. National visit estimates were made using standard methods in Analytics Software and Solutions (SAS, Cary, NC). We compared patients in the mid-urgency range in regard to ED lengths of stay, hospital admission rates, and numbers of tests and procedures in comparison to lower or higher acuity levels.

Results

We analyzed 100,962 emergency visits (representing 402,211,907 emergency visits nationwide). In 2011, patients classified as triage levels 1–3 had a higher number of diagnoses (5.5, 5.6 and 4.2, respectively) when compared to those classified as levels 4 and 5 (1.61 and 1.25). This group also underwent a higher number of procedures (1.0, 0.8 and 0.7, versus 0.4 and 0.4), had a higher ED length of stay (220, 280 and 237, vs. 157 and 135), and admission rates (32.2%, 32.3% and 15.5%, vs. 3.1% and 3.6%).

Conclusion

Patients classified as mid-level (3) triage urgency require more resources and have higher indicators of acuity as those in triage levels 4 and 5. These patients’ indicators are more similar to those classified as triage levels 1 and 2.

Copeptin to rule out myocardial infarction in Blacks versus Caucasians

Background:

Copeptin in combination with troponin has been shown to have incremental value for the early rule-out of myocardial infarction, but its performance in Black patients specifically has never been examined. In light of a potential for wider use, data on copeptin in different relevant cohorts are needed. This is the first study to determine whether copeptin is equally effective at ruling out myocardial infarction in Black and Caucasian races.

Methods:

This analysis of the CHOPIN trial included 792 Black and 1075 Caucasian patients who presented to the emergency department with chest pain and had troponin-I and copeptin levels drawn.

Results:

One hundred and forty-nine patients were diagnosed with myocardial infarction (54 Black and 95 Caucasian). The negative predictive value of copeptin at a cut-off of 14 pmol/l (as in the CHOPIN study) for myocardial infarction was higher in Blacks (98.0%, 95% confidence interval (CI) 96.2–99.1%) than Caucasians (94.1%, 95% CI 92.1–95.7%). The sensitivity at 14 pmol/l was higher in Blacks (83.3%, 95% CI 70.7–92.1%) than Caucasians (53.7%, 95% CI 43.2–64.0%). After controlling for age, hypertension, heart failure, chronic kidney disease and body mass index in a logistic regression model, the interaction term had a P value of 0.03. A cut-off of 6 pmol/l showed similar sensitivity in Caucasians as 14 pmol/l in Blacks.

Conclusions:

This is the first study to identify a difference in the performance of copeptin to rule out myocardial infarction between Blacks and Caucasians, with increased negative predictive value and sensitivity in the Black population at a cut-off of 14 pmol/l. This also holds true for non-ST-segment elevation myocardial infarction and, although numbers were small, similar trends exist in the normal troponin population. This may have significant implications for early rule-out strategies using copeptin.

Are Well-Informed Potential Trial Participants More Likely to Participate?

Bearing in mind the importance of the informed consent, flaws in this process may be a barrier to participants' recruitment. Our objective was to determine the relationship between the degree of comprehension of the informed consent document plus the importance given to individual elements by potential participants of a hypothetical trial and their willingness to participate in such trials. We performed an Online Survey simulating an emergency department trial recruitment, posteriorly evaluating participants' ratings of importance and self-assessed comprehension of specific topics of the informed consent document. Only 10% of the sample read the entire document. Some specific topics were associated with willingness to participate in the hypothetical trial, but simple composite additive scores of comprehension and importance were not. We concluded that participants in general do not read the entire informed consent document and that importance given to specific topics may influence willingness to participate.

Critical Care Air Transport Team severe traumatic brain injury short-term outcomes during flight for Operation Iraqi Freedom/Operation Enduring Freedom

INTRODUCTION

Our understanding of the expertise and equipment required to air transport injured soldiers with severe traumatic brain injuries (TBIs) continue to evolve.

METHODS

We conducted a retrospective chart review of characteristics, interventions required and short-term outcomes of patients with severe TBI managed by the US Air Force Critical Care Air Transport Teams (CCATTs) deployed in support of Operation Iraqi Freedom and Operation Enduring Freedom between 1 June 2007 and 31 August 2010. Patients were cared for based on guidelines given by the Brain Trauma Foundation and the Joint Theater Trauma System by non-neurosurgeon physicians with dedicated neurocritical care training. We report basic characteristics, injuries, interventions required and complications during transport.

RESULTS

Intracranial haemorrhage was the most common diagnosis in this cohort. Most injuries were weapon related. During this study, there were no reported in-flight deaths. The majority of patients were mechanically ventilated. There were 45 patients who required at least one vasopressor to maintain adequate tissue perfusion, including four patients who required three or more. Some patients required intracranial pressure (ICP) management, treatment of diabetes insipidus and/or seizure prophylaxis medications.

CONCLUSIONS

Air transport personnel must be prepared to provide standard critical care but also care specific to TBIs, including ICP control and management of diabetes insipidus. Although these patients and their potential complications are traditionally managed by neurosurgeons, those providers without neurosurgical backgrounds can be provided this training to help fill a wartime need. This study provides data for the future development of air transport guidelines for validating and clearing flight surgeons.

Myocardial Ischemia on Exercise Stress Echocardiography Testing Is Not Associated with Changes in Troponin T Concentrations

BACKGROUND

Some posit that any amount of myocardial ischemia can be detected by high-sensitivity cardiac troponin assays. We hypothesized that patients with myocardial ischemia induced by exercise stress would have significantly higher increases in high-sensitivity cardiac troponin T (hs-cTnT) concentrations than patients without ischemia.

METHODS

We prospectively recruited for a biorepository 317 adult patients who presented to an academic hospital emergency department for evaluation possible ischemic symptoms and who were scheduled for exercise echocardiography. Blood samples were obtained before stress testing and 2-h post-testing. For this study, plasma hs-cTnT (Roche Diagnostics) concentrations were determined in a core laboratory blinded to clinical status. Absolute and relative changes between baseline and 2-h post-stress measurements were compared between patients with and without ischemia induced by stress testing.

RESULTS

The median age was 51 (44.0, 60.0) years, 45.9% were male, and 37.8% were African American. In total, 26 patients (8.1%) had myocardial ischemia induced by exercise. Median baseline, 2-h post-stress, and absolute δ concentrations were, respectively, 6.0, 8.0, and 0.2 ng/L for patients with evidence of ischemia; 3.8, 4.6, and 0.0 ng/L for those without; and 3.9, 4.9, and 0.0 ng/L overall. Baseline and 2-h hs-cTnT concentrations were higher among patients with abnormal stress tests (all P ≤0.05), but absolute and relative changes in hs-cTnT concentrations were not significantly different between individuals with ischemia and individuals without.

CONCLUSIONS

There was no evidence of change in hs-cTnT values in response to exercise stress testing, regardless of the presence of myocardial ischemia.

Wireless, Web-Based Interactive Control of Optical Coherence Tomography with Mobile Devices

Purpose

Optical coherence tomography (OCT) is widely used in ophthalmology clinics and has potential for more general medical settings and remote diagnostics. In anticipation of remote applications, we developed wireless interactive control of an OCT system using mobile devices.

Methods

A web-based user interface (WebUI) was developed to interact with a handheld OCT system. The WebUI consisted of key OCT displays and controls ported to a webpage using HTML and JavaScript. Client–server relationships were created between the WebUI and the OCT system computer. The WebUI was accessed on a cellular phone mounted to the handheld OCT probe to wirelessly control the OCT system. Twenty subjects were imaged using the WebUI to assess the system. System latency was measured using different connection types (wireless 802.11n only, wireless to remote virtual private network [VPN], and cellular).

Results

Using a cellular phone, the WebUI was successfully used to capture posterior eye OCT images in all subjects. Simultaneous interactivity by a remote user on a laptop was also demonstrated. On average, use of the WebUI added only 58, 95, and 170 ms to the system latency using wireless only, wireless to VPN, and cellular connections, respectively. Qualitatively, operator usage was not affected.

Conclusions

Using a WebUI, we demonstrated wireless and remote control of an OCT system with mobile devices.

Translational Relevance

The web and open source software tools used in this project make it possible for any mobile device to potentially control an OCT system through a WebUI. This platform can be a basis for remote, teleophthalmology applications using OCT.

Necessity of hospitalization and stress testing in low risk chest pain patients

BACKGROUND

Copeptin is a marker of endogenous stress including early myocardial infarction(MI) and has value in early rule out of MI when used with cardiac troponin I(cTnI).

OBJECTIVES

The goal of this study was to demonstrate that patients with a normal electrocardiogram and cTnI<0.040μg/l and copeptin<14pmol/l at presentation and after 2 h may be candidates for early discharge with outpatient follow-up potentially including stress testing.

METHODS

This study uses data from the CHOPIN trial which enrolled 2071 patients with acute chest pain. Of those, 475 patients with normal electrocardiogram and normal cTnI(<0.040μg/l) and copeptin<14pmol/l at presentation and after 2 h were considered "low risk" and selected for further analysis.

RESULTS

None of the 475 "low risk" patients were diagnosed with MI during the 180day follow-up period (including presentation). The negative predictive value of this strategy was 100% (95% confidence interval(CI):99.2%-100.0%). Furthermore no one died during follow up. 287 (60.4%) patients in the low risk group were hospitalized. In the "low risk" group, the only difference in outcomes (MI, death, revascularization, cardiac rehospitalization) was those hospitalized underwent revascularization more often (6.3%[95%CI:3.8%-9.7%] versus 0.5%[95%CI:0.0%-2.9%], p=.002). The hospitalized patients were tested significantly more via stress testing or angiogram (68.6%[95%CI:62.9%-74.0%] vs 22.9%[95%CI:17.1%-29.6%], p<.001). Those tested had less cardiac rehospitalizations during follow-up (1.7% vs 5.1%, p=.040).

CONCLUSIONS

In conclusion, patients with a normal electrocardiogram, troponin and copeptin at presentation and after 2 h are at low risk for MI and death over 180days. These low risk patients may be candidates for early outpatient testing and cardiology follow-up thereby reducing hospitalization.

Systematic Molecular Phenotyping: A Path Toward Precision Emergency Medicine?

Precision medicine is an emerging approach to disease treatment and prevention that considers variability in patient genes, environment, and lifestyle. However, little has been written about how such research impacts emergency care. Recent advances in analytical techniques have made it possible to characterize patients in a more comprehensive and sophisticated fashion at the molecular level, promising highly individualized diagnosis and treatment. Among these techniques are various systematic molecular phenotyping analyses (e.g., genomics, transcriptomics, proteomics, and metabolomics). Although a number of emergency physicians use such techniques in their research, widespread discussion of these approaches has been lacking in the emergency care literature and many emergency physicians may be unfamiliar with them. In this article, we briefly review the underpinnings of such studies, note how they already impact acute care, discuss areas in which they might soon be applied, and identify challenges in translation to the emergency department (ED). While such techniques hold much promise, it is unclear whether the obstacles to translating their findings to the ED will be overcome in the near future. Such obstacles include validation, cost, turnaround time, user interface, decision support, standardization, and adoption by end-users.

High Exposure to Organophosphate Flame Retardants in Infants: Associations with Baby Products

Infant products containing polyurethane foam are commonly treated with organophosphate flame retardants (PFRs), including tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and triphenyl phosphate (TPHP). Infants may have greater exposure due to greater contact with these products, yet little is known about levels of exposure or the factors contributing to higher exposure. We recruited children age 2-18 months from North Carolina to investigate PFR exposure (n = 43; recruited 2014-2015). Parents provided information on potential sources and modifiers of exposure, and reported whether they owned common infant products. We measured five PFR metabolites in urine samples collected from children. TDCIPP and TPHP metabolites (bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP)) were most commonly detected (>93% detect). Other metabolites were detected infrequently (<35% detect). Although we did not observe a clear age trend for infants, BDCIPP levels were substantially higher than those reported for adults (geometric mean = 7.3 ng/mL). The number of infant products owned was strongly associated with BDCIPP; children with >16 products had BDCIPP levels that were 6.8 times those with <13 (p = 0.02). Infants attending daycare centers also had higher BDCIPP levels (3.7 times those of others; p = 0.07), suggesting time spent in this microenvironment contributes to higher exposure. In contrast, DPHP levels were not related to products owned, time in different microenvironments, or behavior.