Implementation and Integration of Prehospital ECGs Into Systems of Care for Acute Coronary Syndrome

Feasibility of patch-type wireless 12-lead electrocardiogram in laypersons

Various efforts have been made to diagnose acute cardiovascular diseases (CVDs) early in patients. However, the sole option currently is symptom education. It may be possible for the patient to obtain an early 12-lead electrocardiogram (ECG) before the first medical contact (FMC), which could decrease the physical contact between patients and medical staff. Thus, we aimed to verify whether laypersons can obtain a 12-lead ECG in an off-site setting for clinical treatment and diagnosis using a patch-type wireless 12-lead ECG (PWECG). Participants who were ≥ 19 years old and under outpatient cardiology treatment were enrolled in this simulation-based one-arm interventional study. We confirmed that participants, regardless of age and education level, can use the PWECG on their own. The median age of the participants was 59 years (interquartile range [IQR] = 56-62 years), and the median duration to obtain a 12-lead ECG result was 179 s (IQR = 148-221 s). With appropriate education and guidance, it is possible for a layperson to obtain a 12-lead ECG, minimizing the contact with a healthcare provider. These results can be used subsequently for treatment.

No "July Effect" in the management and outcomes of acute myocardial infarction: An 18-year United States national study

BACKGROUND

There has been conflicting reports on the effect of new trainees on clinical outcomes at teaching hospitals in the first training month (July in the United States of America). We sought to assess this "July effect" in a contemporary acute myocardial infarction (AMI) population.

METHODS

Adult (>18 years) AMI hospitalizations in May and July in urban teaching and urban nonteaching hospitals in the United States were identified from the HCUP-NIS database (2000-2017). In-hospital mortality was compared between May and July admissions. A difference-in-difference analysis comparing a change in outcome from May to July in teaching hospitals to a change in outcome from May to July in nonteaching hospitals was also performed.

RESULTS

A total of 1,312,006 AMI hospitalizations from urban teaching (n = 710,593; 54.2%) or nonteaching (n = 601,413; 45.8%) hospitals in the months of May and July were evaluated. May admissions in teaching hospitals, had greater comorbidity, higher rates of acute multiorgan failure (10.6% vs. 10.2%, p < 0.001) and lower rates of cardiac arrest when compared to July admissions. July AMI admissions had lower in-hospital mortality compared to May (5.6% vs. 5.8%; adjusted odds ratio 0.94 [95% confidence interval 0.92-0.97]; p < 0.001) in teaching hospitals. Using the difference-in-difference model, there was no evidence of a July effect for in-hospital mortality (p = 0.19).

CONCLUSIONS

There was no July effect for in-hospital mortality in this contemporary AMI population.

Incorporation of Serial 12-Lead Electrocardiogram With Machine Learning to Augment the Out-of-Hospital Diagnosis of Non-ST Elevation Acute Coronary Syndrome

STUDY OBJECTIVE

Ischemic electrocardiogram (ECG) changes are subtle and transient in patients with suspected non-ST-segment elevation (NSTE)-acute coronary syndrome. However, the out-of-hospital ECG is not routinely used during subsequent evaluation at the emergency department. Therefore, we sought to compare the diagnostic performance of out-of-hospital and ED ECG and evaluate the incremental gain of artificial intelligence-augmented ECG analysis.

METHODS

This prospective observational cohort study recruited patients with out-of-hospital chest pain. We retrieved out-of-hospital-ECG obtained by paramedics in the field and the first ED ECG obtained by nurses during inhospital evaluation. Two independent and blinded reviewers interpreted ECG dyads in mixed order per practice recommendations. Using 179 morphological ECG features, we trained, cross-validated, and tested a random forest classifier to augment non ST-elevation acute coronary syndrome (NSTE-ACS) diagnosis.

RESULTS

Our sample included 2,122 patients (age 59 [16]; 53% women; 44% Black, 13.5% confirmed acute coronary syndrome). The rate of diagnostic ST elevation and ST depression were 5.9% and 16.2% on out-of-hospital-ECG and 6.1% and 12.4% on ED ECG, with ∼40% of changes seen on out-of-hospital-ECG persisting and ∼60% resolving. Using expert interpretation of out-of-hospital-ECG alone gave poor baseline performance with area under the receiver operating characteristic (AUC), sensitivity, and negative predictive values of 0.69, 0.50, and 0.92. Using expert interpretation of serial ECG changes enhanced this performance (AUC 0.80, sensitivity 0.61, and specificity 0.93). Interestingly, augmenting the out-of-hospital-ECG alone with artificial intelligence algorithms boosted its performance (AUC 0.83, sensitivity 0.75, and specificity 0.95), yielding a net reclassification improvement of 29.5% against expert ECG interpretation.

CONCLUSION

In this study, 60% of diagnostic ST changes resolved prior to hospital arrival, making the ED ECG suboptimal for the inhospital evaluation of NSTE-ACS. Using serial ECG changes or incorporating artificial intelligence-augmented analyses would allow correctly reclassifying one in 4 patients with suspected NSTE-ACS.

Emergency Interhospital Transfer of Patients With ST-Segment-Elevation Myocardial Infarction: Call 9-1-1-The American Heart Association Mission: Lifeline Program

The American Heart Association Mission: Lifeline program objectives are to improve the quality of care and outcomes for patients with ST-segment-elevation myocardial infarction. Every minute of delay in treatment adversely affects 1-year mortality. Transfer of patients safely and timely to hospitals with primary percutaneous coronary intervention capability is needed to improve outcomes. But treatment times continue to show delays, especially during interhospital transfers. A simple 3-step process of an interhospital "Call 9-1-1" protocol may expedite this process. This STAT TRANSFER process uses a systems approach that considers diverse ways in which patients access care, how EMS responds and determines destinations, how referring hospital transfers are performed, urban and rural differences, and how receiving hospitals prepare for an incoming patient with ST-segment-elevation myocardial infarction. This initiative suggests a strategy to reduce variability in interhospital transfer times using a STAT TRANSFER and a Call 9-1-1 process in a system of care that involves all stakeholders.

Paramedic Ability in Interpreting Electrocardiogram with ST-segment Elevation Myocardial Infarction (STEMI) in Saudi Arabia

Objective

To evaluate paramedic ability in recognizing 12-lead Electrocardiogram (ECG) with ST-segment Elevation myocardial infarction (STEMI) in Saudi Arabia.

Methods

This is a quantitative exploratory cross-sectional study using an electronic survey of paramedics was conducted between June and September 2021. The survey included demographics, educational and clinical experiences, and multiple 12-lead ECG strip questions to assess participants’ ability to recognize STEMI. We reported the overall sensitivity, specificity, and correct proportions with 95% Confidence Intervals (CI).

Results

Eighty-four paramedics completed the survey, and 65% of them were between 24 and 29 years old, with a median, of three years of field experience. Overall sensitivity and specificity were 58.39% (95% CI, 50.4% to 66.1%) and 29.01% (95% CI, 25.15% to 33.1%), respectively. In total, 67.1% correctly identified inferior STEMI, whereas only 50% correctly identified lateral STEMI. Both STEMIs were correctly identified by 41%, and the majority misinterpreted STEMI mimics (ECG rhythms with similar ECG morphology to STEMI). The proportion who correctly recognized left bundle branch block was 14.8%, pericarditis was 10.9%, and ventricular pacing was 1.4%. However, almost third of participants correctly identified right bundle branch block (32.9%) and left ventricle hypertrophy (30.7%). Overall, there was no correlation between the correct ECG interpretation of STEMIs and educational and clinical experiences.

Conclusion

Paramedics were able to identify STEMI events in prehospital settings with moderate sensitivity and low specificity with limited ability to differentiate between STEMI and STEMI mimics. Therefore, additional training in ECG interpretation could improve their clinical decision-making, and to ensure that proper care and treatment is provided. Further research on a large, representative sample of paramedics across the country could provide more definitive evidence to establish a greater degree of accuracy in detecting STEMI in prehospital settings.

Utility of prehospital electrocardiogram interpretation in ST-segment elevation myocardial infarction utilizing computer interpretation and transmission for interventional cardiologist consultation

Objectives

We examined the appropriateness of prehospital cardiac catheter laboratory activation (CCL‐A) in ST‐segment elevation myocardial infarction (STEMI) utilizing the University of Glasgow algorithm (UGA) and remote interventional cardiologist consultation.

Background

The incremental benefit of prehospital electrocardiogram (PH‐ECG) transmission on the diagnostic accuracy and appropriateness of CCL‐A has been examined in a small number of studies with conflicting results.

Methods

We identified consecutive PH‐ECG transmissions between June 2, 2010 and October 6, 2016. Blinded adjudication of ECGs, appropriateness of CCL‐A, and index diagnoses were performed using the fourth universal definition of MI. The primary outcome was the appropriate CCL‐A rate. Secondary outcomes included rates of false‐positive CCL‐A, inappropriate CCL‐A, and inappropriate CCL nonactivation.

Results

Among 1088 PH‐ECG transmissions, there were 565 (52%) CCL‐As and 523 (48%) CCL nonactivations. The appropriate CCL‐A rate was 97% (550 of 565 CCL‐As), of which 4.9% (n = 27) were false‐positive. The inappropriate CCL‐A rate was 2.7% (15 of 565 CCL‐As) and the inappropriate CCL nonactivation rate was 3.6% (19 of 523 CCL nonactivations). Reasons for appropriate CCL nonactivation (n = 504) included nondiagnostic ST‐segment elevation (n = 128, 25%), bundle branch block (n = 132, 26%), repolarization abnormality (n = 61, 12%), artefact (n = 72, 14%), no ischemic symptoms (n = 32, 6.3%), severe comorbidities (n = 26, 5.2%), transient ST‐segment elevation (n = 20, 4.0%), and others.

Conclusions

PH‐ECG interpretation utilizing UGA with interventional cardiologist consultation accurately identified STEMI with low rates of inappropriate and false‐positive CCL‐As, whereas using UGA alone would have almost doubled CCL‐As. The benefits of cardiologist consultation were identifying “masquerading” STEMI and avoiding unnecessary CCL‐As.

Predictors of Hyperkalemia among Patients on Maintenance Hemodialysis Transported to the Emergency Department by Ambulance

BACKGROUND

Hyperkalemia is common among patients on maintenance hemodialysis (HD) and is associated with mortality. We hypothesized that clinical characteristics available at time of paramedic assessment before emergency department (ED) ambulance transport (ambulance-ED) would associate with severe hyperkalemia (K≥6 mmol/L). Rapid identification of patients who are at risk for hyperkalemia and thereby hyperkalemia-associated complications may allow paramedics to intervene in a timely fashion, including directing emergency transport to dialysis-capable facilities.

METHODS

Patients on maintenance HD from a single paramedic provider region, who had at least one ambulance-ED and subsequent ED potassium from 2014 to 2018, were examined using multivariable logistic regression to create risk prediction models inclusive of prehospital vital signs, days from last dialysis, and the presence of prehospital electrocardiogram (ECG) features of hyperkalemia. We used bootstrapping with replacement to validate each model internally, and performance was assessed by discrimination and calibration.

RESULTS

Among 704 ambulance-ED visits, severe hyperkalemia occurred in 75 (11%); 26 patients with ED hyperkalemia did not have a prehospital ECG. Younger age at transport, longer HD vintage, more days from last hemodialysis session (OR=49.84; 95% CI, 7.72 to 321.77 for ≥3 days versus HD the same day [before] ED transport), and prehospital ECG changes (OR=6.64; 95% CI, 2.31 to 19.12) were independently associated with severe ED hyperkalemia. A model incorporating these factors had good discrimination (c-statistic 0.82; 95% CI, 0.76 to 0.89) and, using a cutoff of 25% probability, correctly classified patients 89% of the time.

CONCLUSIONS

Characteristics available at the time of ambulance-ED were associated with severe ED hyperkalemia. An awareness of these associations may allow health care providers to define novel care pathways to ensure timely diagnosis and management of hyperkalemia.

Impact of paramedic education on door-to-balloon times and appropriate use of the primary PCI pathway in ST-elevation myocardial infarction

OBJECTIVE

Evidence supports improved outcomes and reduced mortality with rapid reperfusion through primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI). UK national audit data (Myocardial Ischaemia National Audit Project [MINAP]) demonstrates minor improvements in door-to-balloon times (DTB) of <90 min but increasing call-to-balloon times (CTB). We evaluate the effect of a regional Cardiologist delivered paramedic education programme (PEP) on DTB times and appropriate use of the PPCI pathway.

METHODS

This was a prospective single-centre study of patients with STEMI brought directly to hospital via ambulance services. Data sources included ambulance charts, in-patient notes, British Cardiovascular Interventional Society (BCIS) database and local MINAP data. All DTB breaches were investigated. A local PEP was implemented with focus on ECG interpretation, STEMI diagnosis and appropriate use of the PPCI pathway. Non-parametric Wilcoxon rank test was used for comparisons of DTB and CTB times between direct versus ED-associated cath lab transfer.

RESULTS

A total of 728 patients with STEMI were admitted directly to our centre via ambulance, 66% (n=484) directly to the Catheterisation Laboratory (Cath Lab) and 34% (n=244) via the Emergency Department (ED). There was a significant increase in median DTB, 83 vs 37 min (p<0.001) and median CTB 144 vs 97.5 min (p<0.001) when transfer to the Cath Lab occurred via the ED versus direct transfer. The PEP increased direct cath lab transfers (52%-85%) and generated annual reductions in median DTB times, with sustained improvement seen throughout the 7-year study period.

CONCLUSIONS

Paramedic education increases direct transfer of STEMI patients to the Cath Lab, and reduces DTB times. This is an effective and reproducible intervention to facilitate timely reperfusion in STEMI.

Systems of Care for ST-Segment-Elevation Myocardial Infarction: A Policy Statement From the American Heart Association

The introduction of Mission: Lifeline significantly increased timely access to percutaneous coronary intervention for patients with ST-segment-elevation myocardial infarction (STEMI). In the years since, morbidity and mortality rates have declined, and research has led to significant developments that have broadened our concept of the STEMI system of care. However, significant barriers and opportunities remain. From community education to 9-1-1 activation and emergency medical services triage and from emergency department and interfacility transfer protocols to postacute care, each critical juncture presents unique challenges for the optimal care of patients with STEMI. This policy statement sets forth recommendations for how the ideal STEMI system of care should be designed and implemented to ensure that patients with STEMI receive the best evidence-based care at each stage in their illness.

Sex differences in emergency medical services management of patients with myocardial infarction: analysis of routinely collected data for over 110,000 patients

Emergency medical services (EMS) activation is an integral component in managing individuals with myocardial infarction (MI). EMS play a crucial role in early MI symptom recognition, prompt transport to percutaneous coronary intervention centres and timely administration of management. The objective of this study was to examine sex differences in prehospital EMS care of patients hospitalized with Ml using data from a retrospective population-based cohort study of linked health administrative data for people with a hospital diagnosis of MI in Australia (2001-18).

Prehospital ECG with ST-depression and T-wave inversion are associated with new onset heart failure in individuals transported by ambulance for suspected acute coronary syndrome

BACKGROUND

Prehospital electrocardiogram(s) (ECG) can improve early detection of acute coronary syndrome (ST-segment elevation myocardial infarction [STEMI], non-STEMI, and unstable angina) and inform prehospital activation of cardiac catheterization lab; thus, reducing total ischemic time and improving patient outcomes. Less is known, however, about the association of prehospital ECG ischemic findings and long term adverse clinical events. With this in mind, this study was designed to examine the: 1) frequency of prehospital ECGs for acute myocardial ischemia (ST-elevation, ST-depression, and/or T-wave inversion); and, 2) whether any of these specific ECG features are associated with adverse clinical events within 30 day of initial presentation to the emergency department (ED).

METHODS

We included consecutive patients ≥ 21 years during a five-year period (2013-2017), who were transported by ambulance to the ED with non-traumatic chest pain and/or anginal equivalent(s) and had a prehospital 12‑lead ECG. Two cardiologists (LG, EC), blinded to clinical data, interpreted the 12‑lead ECGs applying current guideline based ischemia criteria. Adverse clinical events, return to ED, and rehospitalization evaluated at 30-days.

RESULTS

We identified 3646 patients (mean age, 59.7 years ±15.7; 45% female) with ECGs, of which N = 3587 had data on the three ischemic markers of interest. Of these, 1762 (49.1%) had ECG evidence of ischemia. In adjusted logistic regression models, those with T-wave inversion had a higher odds (OR = 1.59) of new onset heart failure, while ST-elevation was associated with lower odds (OR = 0.69). Patients with ST-depression had higher odds of new onset heart failure and death within 30 days (OR = 1.29, 1.49 respectively), but this association attenuated after controlling for other ECG features.

CONCLUSIONS

ST-depression and/or T-wave inversion are independent predictors of new onset heart failure, within 30 days of initial ED presentation. Our study in a large cohort of patients, suggests that using ECG ST-elevation alone may not capture patients with ischemia who may benefit from aggressive anti-ischemic therapies to reduce myocardial damage with resultant heart failure.

Disparities in Emergency Medical Services Time Intervals for Patients with Suspected Acute Coronary Syndrome: Findings from the North Carolina Prehospital Medical Information System

Background

Timely emergency medical services (EMS) response, management, and transport of patients with suspected acute coronary syndrome (ACS) significantly reduce delays to emergency treatment and improve outcomes. We evaluated EMS response, scene, and transport times and adherence to proposed time benchmarks for patients with suspected ACS in North Carolina from 2011 to 2017.

Methods and Results

We conducted a population‐based, retrospective study with the North Carolina Prehospital Medical Information System, a statewide electronic database of all EMS patient care reports. We analyzed 2011 to 2017 data on patient demographics, incident characteristics, EMS care, and county population density for EMS‐suspected patients with ACS, defined as a complaint of chest pain or suspected cardiac event and documentation of myocardial ischemia on prehospital ECG or prehospital activation of the cardiac care team. Descriptive statistics for each EMS time interval were computed. Multivariable logistic regression was used to quantify relationships between meeting response and scene time benchmarks (11 and 15 minutes, respectively) and prespecified covariates. Among 4667 patients meeting eligibility criteria, median response time (8 minutes) was shorter than median scene (16 minutes) and transport (17 minutes) time. While scene times were comparable by population density, patients in rural (versus urban) counties experienced longer response and transport times. Overall, 62% of EMS encounters met the 11‐minute response time benchmark and 49% met the 15‐minute scene time benchmark. In adjusted regression analyses, EMS encounters of older and female patients and obtaining a 12‐lead ECG and venous access were independently associated with lower adherence to the scene time benchmark.

Conclusions

Our statewide study identified urban–rural differences in response and transport times for suspected ACS as well as patient demographic and EMS care characteristics related to lower adherence to scene time benchmark. Strategies to reduce EMS scene times among patients with ACS need to be developed and evaluated.

Regional Systems of Care in ST Elevation Myocardial Infarction

ST-segment elevation myocardial infarction is a medical emergency with significant health care delivery challenges to ensure rapid triage and treatment. Several developments over the past decades have led to improved care delivery, decreased time to reperfusion, and decreased mortality. Still, significant challenges remain to further optimize the delivery of care for this patient population.

Prehospital Evaluation, ED Management, Transfers, and Management of Inpatient STEMI

ST elevation myocardial infarction diagnoses have reduced in number over the past 10 years; however, associated morbidity and mortality remain high. Societal guidelines focus on early diagnosis and timely access to reperfusion, preferably percutaneous coronary intervention (PCI), with fibrinolytics reserved for those who cannot receive timely PCI. Proposed algorithms recommend emergency department bypass in stable patients with a clear diagnosis to reduced door-to-balloon time. Emergency providers should limit their evaluation, focusing on life-threatening comorbidities, unstable vitals, or contraindications to a catheterization laboratory. In-hospital patients prove diagnostically challenging because they may be unable to express symptoms, and reperfusion strategies can complicate other diagnoses.

Accuracy of ECG chest electrode placements by paramedics: an observational study

Background:

The use of the 12-lead electrocardiogram (ECG) is common in sophisticated pre-hospital emergency medical services but its value depends upon accurate placement of the ECG electrodes. Several studies have shown widespread variation in the placement of chest electrodes by other health professionals but no studies have addressed the accuracy of paramedics. The main objective of this study was to ascertain the accuracy of the chest lead placements by registered paramedics.

Methods:

Registered paramedics who attended the Emergency Services Show in Birmingham in September 2018 were invited to participate in this observational study. Participants were asked to place the chest electrodes on a male model in accordance with their current practice. Correct positioning was determined against the Society for Cardiological Science and Technology’s 2017 clinical guidelines for recording a standard 12-lead ECG, with a tolerance of 19 mm being deemed acceptable based upon previous studies.

Results:

Fifty-two eligible participants completed the study. Measurement of electrode placement in the vertical and horizontal planes showed a high level of inaccuracy, with 3/52 (5.8%) participants able to accurately place all chest electrodes. In leads V₁–V₃, the majority of incorrect placements were related to vertical displacement, with most participants able to identify the correct horizontal position. In V₄, the tendency was to place the electrode too low and to the left of the pre-determined position, while V₅ tended to be below the expected positioning but in the correct horizontal alignment. There was a less defined pattern of error in V₆, although vertical displacement was more likely than horizontal displacement.

Conclusions:

Our study identified a high level of variation in the placement of chest ECG electrodes, which could alter the morphology of the ECG. Correct placement of V₁ improved placement of other electrodes. Improved initial and refresher training should focus on identification of landmarks and correct placement of V₁.

Effect of Real-Time Physician Oversight of Prehospital STEMI Diagnosis on ECG-Inappropriate and False Positive Catheterization Laboratory Activation

Background

ST-elevation myocardial infarction diagnosis at first medical contact (FMC) and prehospital cardiac catheterization laboratory (CCL) activation are associated with reduced total ischemic time and therefore have become the dominant ST-elevation myocardial infarction referral method in primary percutaneous coronary intervention systems. We sought to determine whether physician oversight was associated with improved diagnostic performance in a prehospital CCL activation system and what effect the additional interpretation has on treatment delay.

Methods

Between 2012 and 2015, all patients in 2 greater Montreal catchment areas with a chief symptom of chest paint or dyspnea had an in-the-field electrocardiogram (ECG). A machine diagnosis of "acute myocardial infarction" resulted either in automatic CCL (automated cohort without oversight) or transmission of the ECG to the receiving centre emergency physician for reinterpretation before CCL activation. System performance was assessed in terms of the proportion of false positive and inappropriate activations (IA), as well as the proportion of patients with FMC-to-device times ≤ 90 minutes.

Results

Four hundred twenty-eight (428) activations were analyzed (311 automated; 117 with physician oversight). Physician oversight tended to decrease IAs (7% vs 3%; P = 0.062), but was also associated with a smaller proportion of patients achieving target FMC-to-device (76% vs 60%; P < 0.001). There was no significant effect on the proportion of false positive activation.

Conclusions

Real-time physician oversight might be associated with fewer IAs, but also appears to have a deleterious effect on FMC-to-device performance. Identifying predictors of IA could improve overall performance by selecting ECGs that merit physician oversight and streamlining others. Larger clinical studies are warranted.

Systematic Review of Clinical Decision Support Systems for Prehospital Acute Coronary Syndrome Identification

OBJECTIVES

Timely prehospital diagnosis and treatment of acute coronary syndrome (ACS) are required to achieve optimal outcomes. Clinical decision support systems (CDSS) are platforms designed to integrate multiple data and can aid with management decisions in the prehospital environment. The review aim was to describe the accuracy of CDSS and individual components in the prehospital ACS management.

METHODS

This systematic review examined the current literature regarding the accuracy of CDSS for ACS in the prehospital setting, the influence of computer-aided decision-making and of 4 components: electrocardiogram, biomarkers, patient history, and examination findings. The impact of these components on sensitivity, specificity, and positive and negative predictive values was assessed.

RESULTS

A total of 11,439 articles were identified from a search of databases, of which 199 were screened against the eligibility criteria. Eight studies were found to meet the eligibility and quality criteria. There was marked heterogeneity between studies which precluded formal meta-analysis. However, individual components analysis found that patient history led to significant improvement in the sensitivity and negative predictive values. CDSS which incorporated all 4 components tended to show higher sensitivities and negative predictive values. CDSS incorporating computer-aided electrocardiogram diagnosis showed higher specificities and positive predictive values.

CONCLUSIONS

Although heterogeneity precluded meta-analysis, this review emphasizes the potential of ACS CDSS in prehospital environments that incorporate patient history in addition to integration of multiple components. The higher sensitivity of certain components, along with higher specificity of computer-aided decision-making, highlights the opportunity for developing an integrated algorithm with computer-aided decision support.

Diagnostic Performance of Prehospital Point-of-Care Troponin Tests to Rule Out Acute Myocardial Infarction: A Systematic Review

INTRODUCTION

Chest pain is one of the most common reasons for 999 calls and transfers to the emergency department (ED). In these patients, acute myocardial infarction (AMI) is often the diagnosis that clinicians are seeking to exclude. However, only a minority of those patients have AMI, causing a substantial financial burden to health services. Cardiac troponin (cTn) is the reference standard biomarker for the diagnosis of AMI. Several commercially available point-of-care (POC) cTn assays are portable and could feasibly be used in an ambulance. The aim of this paper is to systematically review existing evidence for the use of POC cTn assays in the prehospital setting to rule out AMI.

METHODS

A systematic search was conducted on EMBASE, MEDLINE, and CINAHL Plus databases, reference lists, and relevant grey literature, including combinations of the relevant terms. Papers published in English language since the year 2000 were eligible for inclusion. A narrative synthesis of the evidence was then undertaken.

RESULTS

The initial search and cross-referencing revealed a total of 350 papers, of which 243 were excluded. Seven papers were included in the systematic literature review.

CONCLUSION

Current evidence does not support the use of POC troponin assays to exclude AMI due to issues with diagnostic accuracy and insufficient high-quality evidence.

Factors associated with emergency medical service delays in suspected ST-elevation myocardial infarction in Victoria, Australia: A retrospective study

OBJECTIVE

To assess the effect of patient and system characteristics on emergency medical service (EMS) delays prior to arrival at hospital in suspected ST-elevation myocardial infarction (STEMI).

METHODS

This was a retrospective observational study of 1739 patients who presented with suspected STEMI to the EMS in Melbourne, Australia between October 2011 and January 2014. Our primary outcome measure was call-to-hospital time, defined as the time in minutes from emergency call to hospital arrival. We examined the association of patient and system characteristics on call-to-hospital time using multivariable linear regression.

RESULTS

The mean call-to-hospital time was 60.1 min (standard deviation 20.5) and the median travel distance was 13.0 km (interquartile range 7.2-23.1). In the multivariable model, patient characteristics associated with longer call-to-hospital time were age ≥75 years (2.3 min; 95% confidence interval [CI] 0.6-4.0), female sex (1.9 min; 95% CI 0.3-3.4), pre-existing mental health disorder (4.0 min; 95% CI 1.9-6.1) or musculoskeletal disease (2.7 min; 95% CI 1.0-4.4), absence of chest pain (3.0 min; 95% CI 1.1-4.8), and presentation with clinical complications. System factors associated with call-to-hospital time include lower dispatch priority (12.7 min; 95% CI 9.0-16.5) and non-12-lead electrocardiography (ECG) capable ambulance first on scene (4.5 min; 95% CI 3.1-5.8). Patients who were not initially attended by a 12-lead capable ambulance were less likely to receive a 12-lead ECG within 10 min (18.5% vs 71.0%, P < 0.001).

CONCLUSION

A range of patient and system factors may influence EMS delays in STEMI. However, optimising dispatch prioritisation and widespread availability of prehospital 12-lead ECG could lead to substantial reduction in time to treatment.

Emergency Medical Services Utilization by Children

OBJECTIVE

The aim of this study was to compare demographic and clinical features of children (0-14 years old) who arrived at general emergency departments (EDs) by emergency medical services (EMS) to those who arrived by private vehicles and other means in a rural, 3-county region of northern California.

METHODS

We reviewed 507 ED records of children who arrived at EDs by EMS and those who arrived by other means in 2013. We also analyzed prehospital procedures performed on all children transported to an area hospital by EMS.

RESULTS

Children arriving by EMS were older (9.0 vs 6.0 years; P < 0.001), more ill (mean Severity Classification Score, 2.9 vs 2.4; P < 0.001), and had longer lengths of stay (3.6 vs 2.1 hours; P < 0.001) compared with children who were transported to the EDs by other means. Children transported by EMS received more subspecialty consultations (18.7% vs 6.9%; P < 0.05) and had more diagnostic testing, including laboratory testing (22.9% vs 10.6%; P < 0.001), radiography (39.7% vs 20.8%; P < 0.001), and computed tomography scans (16.8% vs 2.9%; P < 0.001). Children arriving by EMS were transferred more frequently (8.8% vs 1.6%; P < 0.001) and had higher mean Severity Classification Scores compared with children arriving by other transportation even after adjusting for age and sex (β = 0.48; 95% confidence interval, 0.35-0.61; P < 0.001). Older children received more prehospital procedures compared with younger children, and these were of greater complexity and a wider spectrum.

CONCLUSIONS

Children transported to rural EDs via EMS are more ill and use more medical resources compared with those who arrive to the ED by other means of transportation.

2019 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Guidelines on the Acute Management of ST-Elevation Myocardial Infarction: Focused Update on Regionalization and Reperfusion

Rapid reperfusion of the infarct-related artery is the cornerstone of therapy for the management of acute ST-elevation myocardial infarction (STEMI). Canada's geography presents unique challenges for timely delivery of reperfusion therapy for STEMI patients. The Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology STEMI guideline was developed to provide advice regarding the optimal acute management of STEMI patients irrespective of where they are initially identified: in the field, at a non-percutaneous coronary intervention-capable centre or at a percutaneous coronary intervention-capable centre. We had also planned to evaluate and incorporate sex and gender considerations in the development of our recommendations. Unfortunately, inadequate enrollment of women in randomized trials, lack of publication of main outcomes stratified according to sex, and lack of inclusion of gender as a study variable in the available literature limited the feasibility of such an approach. The Grading Recommendations, Assessment, Development, and Evaluation system was used to develop specific evidence-based recommendations for the early identification of STEMI patients, practical aspects of patient transport, regional reperfusion decision-making, adjunctive prehospital interventions (oxygen, opioids, antiplatelet therapy), and procedural aspects of mechanical reperfusion (access site, thrombectomy, antithrombotic therapy, extent of revascularization). Emphasis is placed on integrating these recommendations as part of an organized regional network of STEMI care and the development of appropriate reperfusion and transportation pathways for any given region. It is anticipated that these guidelines will serve as a practical template to develop systems of care capable of providing optimal treatment for a wide range of STEMI patients.

Characteristics of Prehospital Electrocardiogram Use in North Carolina Using a Novel Linkage of Emergency Medical Services and Emergency Department Data

Objective: Prehospital electrocardiography (ECG) is recommended for patients with suspected acute coronary syndrome (ACS), yet only 20-80% of chest pain patients receive a prehospital ECG. Less is known about prehospital ECG use in patients with less common complaints (e.g., fatigue) suspicious for ACS who are transported by emergency medical services (EMS). The aims of this study were to determine: (1) the proportion of patients with chest pain and less typical complaints, and (2) patient characteristics associated with prehospital ECG use in patients transported by EMS to emergency departments across North Carolina. Methods: A novel linked database was created between prehospital and emergency department (ED) patient care data from the North Carolina Prehospital Medical Information System and the North Carolina Disease Event Tracking and Epidemiologic Collection Tool. Institutional review board approval and a data use agreement were received prior to the start of the study. Patients ≥21 transported during 2010-14 by EMS with select variables were included. We examined patients' complaints (symptoms), characteristics (e.g., race, ethnicity, final hospital diagnosis), and prehospital ECG use (yes/no). Analysis included descriptive statistics and mixed logistic regression. Results: During 2010-14, there were 1,967,542 patients with linked EMS-ED data (mean age: 56.9 [SD: 22.2], 43.2% male, 63.7% White). Of these, 643,174 (32.6%) received a prehospital ECG. Patients with prehospital ECG presented with the following complaints: 20% chest pain; 10% shortness of breath; 6% abdominal pain/problems; 6% altered level of consciousness; 5% syncope/dizziness; 4% palpitations; 12% other complaints; and 37% missing. Patients' presenting complaints were the strongest predictor of prehospital ECG use, adjusting for age, sex, race, ethnicity, urbanicity, and date and time of EMS dispatch. Conclusions: Patients with chest pain were significantly more likely to receive a prehospital ECG compared to those with less typical but suspicious complaints for ACS. Patients with less common presentations remain disadvantaged for early triage, risk stratification, and intervention prior to the hospital.

A Statewide Assessment of Prehospital Electrocardiography Approaches of Acquisition and Interpretation for ST-Elevation Myocardial Infarction Based on Emergency Medical Services Characteristics

Background: The American Heart Association recommends acquiring and interpreting prehospital electrocardiograms (ECG) for patients transported by Emergency Medical Services (EMS) to the emergency department with symptoms highly suspicious of acute coronary syndrome. If interpreted correctly, prehospital ECGs have the potential to improve early detection of ST-elevation myocardial infarction (STEMI) and inform prehospital activation of the cardiac catheterization laboratory, thus reducing total ischemic time and improving patient outcomes. Standardized protocols for prehospital ECG interpretation methods are lacking due to variations in EMS system design, training, and procedures. Objectives: We aimed to describe approaches for prehospital ECG interpretation in EMS systems across North Carolina (NC), and examine potential differences among systems. Methods: A 35-item internet survey was sent to all NC EMS systems (n = 99). Questions pertaining to prehospital ECG interpretation methods included: paramedic, computerized algorithm (i.e., software interpretation), combined approaches, and/or transmission for physician interpretation, transmission capability, cardiac catheterization laboratory activation, and EMS system characteristics (e.g. rural versus urban). Data were summarized and compared. Results: A total of 96 EMS systems across NC responded to the survey (97% response rate); of these, 69% were rural. EMS medical directors (53%) or EMS administrative directors (42%) completed the majority of surveys. While 91% of EMS systems had a prehospital ECG interpretation protocol in place, only 61% had a written cardiac catheterization laboratory activation policy. More than half (55%) of systems reported paramedic interpretation of prehospital ECGs, followed by a combined paramedic and software interpretation approach (39%), physician interpretation (4%), or software interpretation only approach (2%). Nearly 80% of EMS systems transmitted prehospital ECGs to receiving hospitals (always or sometimes), regardless of interpretation method. All EMS systems had some paid versus non-paid EMS personnel and the majority (86%) had both basic and advanced life support capabilities. Conclusions: Most NC EMS systems had a paramedic only ECG interpretation or paramedic in combination with a computerized algorithm approach. Very few used a physician read approach following transmission, even in rural service areas.

Cancellation of the Cardiac Catheterization Lab After Activation for ST-Segment-Elevation Myocardial Infarction

BACKGROUND

Prehospital ECG-based cardiac catheterization laboratory (CCL) activation for ST-segment-elevation myocardial infarction reduces door-to-balloon times, but CCL cancellations (CCL^X) remain a challenging problem. We examined the reasons for CCL^X, clinical characteristics, and outcomes of patients presenting as ST-segment-elevation myocardial infarction activations who receive emergent coronary angiography (EA) compared with CCL^X.

METHODS AND RESULTS

We reviewed all consecutive CCL activations between January 1, 2012, and December 31, 2014 (n=1332). Data were analyzed comparing 2 groups stratified as EA (n=466) versus CCL^X (n=866; 65%). Reasons for CCL^X included bundle branch block (21%), poor-quality prehospital ECG (18%), non-ST-segment-elevation myocardial infarction ST changes (18%), repolarization abnormality (13%), and arrhythmia (8%). A multivariate logistic regression model using age, peak troponin, and initial ECG findings had a high discriminatory value for determining EA versus CCL^X (C statistic, 0.985). CCL^X subjects were older and more likely to be women, have prior coronary artery bypass grafting, or a paced rhythm ( P<0.0001 for all). All-cause mortality did not differ between groups at 1 year or during the study period (mean follow-up, 2.186±1.167 years; 15.8% EA versus 16.2% CCL^X; P=0.9377). Cardiac death was higher in the EA group (11.8% versus 3.0%; P<0.0001). After adjusting for clinical variables associated with survival, CCL^X was associated with an increased risk for all-cause mortality during the study period (hazard ratio, 1.82; 95% CI, 1.28-2.59; P=0.0009).

CONCLUSIONS

In this study, prehospital ECG without overreading or transmission lead to frequent CCL^X. CCL^X subjects differ with regard to age, sex, risk factors, and comorbidities. However, CCL^X patients represent a high-risk population, with frequently positive cardiac enzymes and similar short- and long-term mortality compared with EA. Further studies are needed to determine how quality improvement initiatives can lower the rates of CCL^X and influence clinical outcomes.

Review article: Impact of 12-lead electrocardiography system of care on emergency medical service delays in ST-elevation myocardial infarction: A systematic review and meta-analysis

To assess the impact of prehospital 12-lead electrocardiography (PH ECG) on emergency medical service (EMS) delay in patients with ST-elevation myocardial infarction (STEMI), we systematically searched five online electronic databases, including MEDLINE, Embase, Emcare, Cochrane Library and CINAHL, between 1990 and August 2017. Controlled trials and observational studies comparing EMS time delays with and without PH ECG in STEMI patients were eligible. Two reviewers independently screened studies for eligibility, extracted data and appraised study quality. The primary outcome was the time elapsed between scene arrival and hospital arrival. The secondary outcomes were response time, scene time, transport time and emergency call-to-hospital arrival time. Random effects models were used to pool weighted mean differences in EMS delay. Seven moderate-quality studies (two controlled trials and five observational) involving 81 005 participants were included in the data synthesis. The primary treatment strategy was in-hospital thrombolysis and percutaneous coronary intervention in four and three studies, respectively. PH ECG was associated with a 7.0 min increase in scene arrival-to-hospital arrival time (three studies; n = 80 628; 95% CI 6.7-7.2; I² = 0.0%) and a 2.9 min increase in scene time (four studies; n = 377; 95% CI 1.2-4.6; I² = 0.0%). PH ECG had no effect on transport or call-to-hospital intervals, although both measures showed evidence of heterogeneity. In patients with STEMI, PH ECG is associated with a modest increase in EMS delays. Measurement and improvement of EMS system delays may help to expedite treatment for STEMI.

Diagnostic value of standard electrocardiogram in acute right ventricular myocardial infarction

Myocardial infarction (MI) (i.e., heart attack) is the irreversible death (necrosis) of heart muscle secondary to prolonged lack of oxygen supply (ischemia) which accounts for a large number of deaths in the hospital. Diagnosis of myocardial infarction is confirmed based on clinical manifestations and electrocardiographic changes along with increased cardiac enzymes. Electrocardiogram (ECG) is one of the safest and easiest methods in the first place. Therefore, this study aimed to investigate the diagnostic value of standard electrocardiogram in the diagnosis of acute right ventricular infarction following lower cardiac infarction. This research was carried out at a time interval of one and a half years to diagnose acute primary infarction. In this method, the diagnostic value of ST↓ in lead I, ST↓ in lead aVL and I ST↓ + aVL, compared with ST↑ in lead V4R was investigated for diagnosis of right ventricular infarction. ST↑ in the lead V4R is a gold standard for the detection of right ventricular MI. All the patients who had the inclusion criteria were allowed to participate in the study. A total of 66 patients participated in the study. Accordingly, 58 (87%) were male and 8 (13%) were female. The mean age of the population was 54.9 ± 11.41. According to the ST↑ standard in lead V4R, 26 patients (39%) had right ventricular myocardial infarction. There was no significant relationship between angina pectoris and premature infarction (P-Value = 0.869). In this study, the right ventricular was most commonly involved in right coronary artery (78%). There was no significant relationship between the occlusion of right coronary artery and right ventricular infarction in 60 patients (P-Value = 0.94). The results showed that electrocardiogram manifestations help determine the occlusion site and the area at risk (ST↓ in lead aVL and aVL + I, sensitivity = 96%). In myocardial infarction, symptoms such as the ST-Segment elevation in lead aVR and ST-Segment depression in the lower leads are possible. Accordingly, in the lower infarction, ST changes in the leads V1-V6 are helpful in detecting patients at risk. Thus, the use of electrocardiogram in acute myocardial infarction helps detect more invasive patients and prevents extensive myocardial damage and other complications.

The VITAL study and overall pooled analysis with the VIPS non-invasive stroke detection device

INTRODUCTION

Effective triage of patients with emergent large vessel occlusion (ELVO) to endovascular therapy capable centers may decrease time to treatment and improve outcome for these patients. Here we performed a derivation study to evaluate the accuracy of a portable, non-invasive, and easy to use severe stroke detector.

METHODS

The volumetric impedance phase shift spectroscopy (VIPS) device was used to assign a bioimpedance asymmetry score to 248 subjects across three cohorts, including 41 subjects presenting as acute stroke codes at a major comprehensive stroke center (CSC), 79 healthy volunteers, and 128 patients presenting to CSCs with a wide variety of brain pathology including additional stroke codes. Diagnostic parameters were calculated for the ability of the device to discern (1) severe stroke from minor stroke and (2) severe stroke from all other subjects. Patients with intracranial hardware were excluded from the analysis.

RESULTS

The VIPS device was able to differentiate severe stroke from minor strokes with a sensitivity of 93% (95% CI 83 to 98), specificity of 92% (95% CI 75 to 99), and an area under the curve (AUC) of 0.93 (95% CI 0.85 to 0.97). The device was able to differentiate severe stroke from all other subjects with a sensitivity of 93% (95% CI 83 to 98), specificity of 87% (95% CI 81 to 92), and an AUC of 0.95 (95% CI 0.89 to 0.96).

CONCLUSION

The VIPS device is a portable, non-invasive, and easy to use tool that may aid in the detection of severe stroke, including ELVO, with a sensitivity of 93% and specificity of 92% in this derivation study. This device has the potential to improve the triage of patients suffering severe stroke.

Diagnostic accuracy of prehospital electrocardiograms interpreted remotely by emergency physicians in myocardial infarction patients

BACKGROUND

Prehospital 12‑lead electrocardiogram (ECG) is the most widely used screening tool for recognition of ST-segment elevation myocardial infarction (STEMI). However, prehospital diagnosis of STEMI based solely on ECGs can be challenging.

OBJECTIVES

To evaluate the ability of emergency department (ED) physicians to accurately interpret prehospital 12‑lead ECGs from a remote location.

METHODS

All suspected prehospital STEMI patients who were transported by EMS and underwent angiography between 2006 and 2014 were included. We reviewed prehospital ECGs and grouped them based on: 1) presence or absence of a culprit artery lesion following angiography; and 2) whether they met the 3rd Universal Definition of Myocardial Infarction. We also described characteristics of ECGs that were misinterpreted by ED physicians.

RESULTS

A total of 625 suspected STEMI cases were reviewed. Following angiography, 94% (590/625) of patients were found having a culprit artery lesion, while 6% (35/625) did not. Among these 35 patients, 24 had ECGs that mimicked STEMI criteria and 9 had non-ischemic signs. Upon ECG reinterpretation, 92% (577/625) had standard STEMI criteria while 8% (48/625) did not. Among these 48 patients, 35 had ischemic signs ECGs and 13 did not. Characteristics of misinterpreted ECGs included pericarditis, early repolarization, STE > 1 mm (1‑lead only), and negative T-wave.

CONCLUSIONS

Remote interpretation of prehospital 12‑lead ECGs by ED physicians was a useful diagnostic tool in this EMS system. Even if the rate of ECG misinterpretation is low, there is still room for ED physicians operating from a remote location to improve their ability to accurately diagnose STEMI patients.

The effects of prearrival direct notification call to interventional cardiologist on door-to-balloon time in patients who required secondary diversion with ST-elevation myocardial infarction for primary percutaneous coronary intervention

Background:

Rapid door-to-balloon times in ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention are associated with favorable outcomes.

Objectives:

We evaluated the effects of prearrival direct notification calls to interventional cardiologists on door-to-balloon time for ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention.

Methods:

A 24-h hotline was created to allow prearrival direct notification calls to interventional cardiologists when transferring ST-elevation myocardial infarction patients. In an urban, tertiary referral center, patients who visited via inter-facility or the emergency department directly were included. Clinical parameters, time to reperfusion therapy, and in-hospital mortality were compared between patients with and without prearrival notifications.

Results:

Of 228 ST-elevation myocardial infarction patients, 95 (41.7%) were transferred with prearrival notifications. In these patients, door-to-balloon time was shorter (50.0 vs 60.0 min, p = 0.010) and the proportion of patients with door-to-balloon time < 90 min was higher (89.5% vs 75.9%, p = 0.034) than patients without notifications. These improvements were more pronounced during “off-duty” hours (52.0 vs 78.0 min, p = 0.001; 88.3% vs 72.3%, p = 0.047, respectively) than during “on-duty” hours (37.5 vs 43.5 min, p = 0.164; 94.4% vs 79.4%, p = 0.274, respectively). In addition, door-to-activation time (–39 vs 11 min, p < 0.001) and door-to-catheterization laboratory arrival time (33 vs 42 min, p = 0.007) were shorter in patients with prearrival notifications than those without. However, in-hospital mortality was similar between the two groups (6.3% vs 6.8%, p = 0.892).

Conclusion:

Prearrival direct notification calls to interventional cardiologists significantly improved the door-to-balloon time and the proportion of patients with door-to-balloon time < 90 min through rapid patient transport in primary percutaneous coronary intervention scheduled hospital and readiness of the catheterization laboratory.

Weekly Checks Improve Real-Time Prehospital ECG Transmission in Suspected STEMI

IntroductionField identification of ST-elevation myocardial infarction (STEMI) and advanced hospital notification decreases first-medical-contact-to-balloon (FMC2B) time. A recent study in this system found that electrocardiogram (ECG) transmission following a STEMI alert was frequently unsuccessful.HypothesisInstituting weekly test ECG transmissions from paramedic units to the hospital would increase successful transmission of ECGs and decrease FMC2B and door-to-balloon (D2B) times.

METHODS

This was a natural experiment of consecutive patients with field-identified STEMI transported to a single percutaneous coronary intervention (PCI)-capable hospital in a regional STEMI system before and after implementation of scheduled test ECG transmissions. In November 2014, paramedic units began weekly test transmissions. The mobile intensive care nurse (MICN) confirmed the transmission, or if not received, contacted the paramedic unit and the department's nurse educator to identify and resolve the problem. Per system-wide protocol, paramedics transmit all ECGs with interpretation of STEMI. Receiving hospitals submit patient data to a single registry as part of ongoing system quality improvement. The frequency of successful ECG transmission and time to intervention (FMC2B and D2B times) in the 18 months following implementation was compared to the 10 months prior. Post-implementation, the time the ECG transmission was received was also collected to determine the transmission gap time (time from ECG acquisition to ECG transmission received) and the advanced notification time (time from ECG transmission received to patient arrival).

RESULTS

There were 388 patients with field ECG interpretations of STEMI, 131 pre-intervention and 257 post-intervention. The frequency of successful transmission post-intervention was 73% compared to 64% prior; risk difference (RD)=9%; 95% CI, 1-18%. In the post-intervention period, the median FMC2B time was 79 minutes (inter-quartile range [IQR]=68-102) versus 86 minutes (IQR=71-108) pre-intervention (P=.3) and the median D2B time was 59 minutes (IQR=44-74) versus 60 minutes (IQR=53-88) pre-intervention (P=.2). The median transmission gap was three minutes (IQR=1-8) and median advanced notification time was 16 minutes (IQR=10-25).

CONCLUSION

Implementation of weekly test ECG transmissions was associated with improvement in successful real-time transmissions from field to hospital, which provided a median advanced notification time of 16 minutes, but no decrease in FMC2B or D2B times. D'ArcyNT, BossonN, KajiAH, BuiQT, FrenchWJ, ThomasJL, ElizarrarazY, GonzalezN, GarciaJ, NiemannJT. Weekly checks improve real-time prehospital ECG transmission in suspected STEMI. Prehosp Disaster Med. 2018;33(3):245-249.

Comprehensive electrocardiogram-to-device time for primary percutaneous coronary intervention in ST-segment elevation myocardial infarction: A report from the American Heart Association mission: Lifeline program

BACKGROUND

Assessing hospital-related network-level primary percutaneous coronary intervention (PCI) performance for ST-segment elevation myocardial infarction (STEMI) is challenging due to differential time-to-treatment metrics based on location of diagnostic electrocardiogram (ECG) for STEMI.

METHODS

STEMI patients undergoing primary PCI at 588 PCI-capable hospitals in AHA Mission: Lifeline (2008-2013) were categorized by initial STEMI identification location: PCI-capable hospitals (Group 1); pre-hospital setting (Group 2); and non-PCI-capable hospitals (Group 3). Patient-specific time-to-treatment categories were converted to minutes ahead of or behind their group-specific mean; average time-to-treatment difference for all patients at a given hospital was termed comprehensive ECG-to-device time. Hospitals were then stratified into tertiles based on their comprehensive ECG-to-device times with negative values below the mean representing shorter (faster) time intervals.

RESULTS

Of 117,857 patients, the proportion in Groups 1, 2, and 3 were 42%, 33%, and 25%, respectively. Lower rates of heart failure and cardiac arrest at presentation are noted within patients presenting to high-performing hospitals. Median comprehensive ECG-to-device time was shortest at -9 minutes (25th, 75th percentiles: -13, -6) for the high-performing hospital tertile, 1 minute (-1, 3) for middle-performing, and 11 minutes (7, 16) for low-performing. Unadjusted rates of in-hospital mortality were 2.3%, 2.6%, and 2.7%, respectively, but the adjusted risk of in-hospital mortality was similar across tertiles.

CONCLUSIONS

Comprehensive ECG-to-device time provides an integrated hospital-related network-level assessment of reperfusion timing metrics for primary PCI, regardless of the location for STEMI identification; further validation will delineate how this metric can be used to facilitate STEMI care improvements.

Implementing Prehospital Evidence-Based Guidelines: A Systematic Literature Review

OBJECTIVE

As prehospital research advances, more evidence-based guidelines (EBGs) are implemented into emergency medical services (EMS) practice. However, incomplete or suboptimal prehospital EBG implementation may hinder improvement in patient outcomes. To inform future efforts, this study's objective was to review existing evidence pertaining to prehospital EBG implementation methods.

METHODS

This study was a systematic literature review and evaluation following the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. PubMed, EMBASE, Scopus, and Google Advanced Search were searched without language or publication date filters for articles addressing prehospital EBG implementation. Conference proceedings, textbooks, and non-English articles were excluded. GRADE was applied to the remaining articles independently by three of five study investigators. Study characteristics and salient findings from the included articles are reported.

RESULTS

The systematic literature review identified 1,367 articles, with 41 meeting inclusion criteria. Most articles described prehospital EBG implementation (n = 24, 59%), or implementation barriers (n = 13, 32%). Common study designs were statement documents (n = 12, 29%), retrospective cohort studies (n = 12, 29%), and cross-sectional studies (n = 9, 22%). Using GRADE, evidence quality was rated low (n = 18, 44%), or very low (n = 23, 56%). Salient findings from the articles included: (i) EBG adherence and patient outcomes depend upon successful implementation, (ii) published studies generally lack detailed implementation methods, (iii) EBG implementation takes longer than planned (mostly for EMS education), (iv) EMS systems' heterogeneity affects EBG implementation, and (v) multiple barriers limit successful implementation (e.g., financial constraints, equipment purchasing, coordination with hospitals, and regulatory agencies). This review found no direct evidence for best prehospital EBG implementation practices. There were no studies comparing implementation methods or implementation in different prehospital settings (e.g., urban vs. rural, advanced vs. basic life support).

CONCLUSIONS

While prehospital EBG implementation barriers are well described, there is a paucity of evidence for optimal implementation methods. For scientific advances to reach prehospital patients, EBG development efforts must translate into EMS practice. Future research should consider comparing implementation methodologies in different prehospital settings, with a goal of defining detailed, reproducible best practices.

Pre-hospital detection of acute ischemic stroke secondary to emergent large vessel occlusion: lessons learned from electrocardiogram and acute myocardial infarction

Currently, there is no device capable of detecting acute ischemic stroke (AIS) secondary to emergent large vessel occlusion (ELVO) in the pre-hospital setting. The inability to reliably identify patients that would benefit from primary treatment with endovascular thrombectomy remains an important limitation to optimizing emergency medical services (EMS) triage models and time-to-treatment. Several clinical grading scales that rely solely on clinical examination have been proposed and have demonstrated only moderate predictive ability for ELVO. Consequently, a technology capable of detecting ELVO in the pre-hospital setting would be of great benefit. An analogous scenario existed decades ago, in which pre-hospital detection of acute myocardial infarction (AMI) was unreliable until the emergence of the 12-lead ECG and its adoption by EMS providers. This review details the implementation of pre-hospital ECG (PHECG) for the detection of AMI and explores how early experience with PHECG may be applied to ELVO detection devices, once they become available.

Adult Chest Pain in the Pediatric Emergency Department: Treatment and Timeliness From Door In To Door Out

OBJECTIVES

The American College of Cardiology Foundation/American Heart Association guidelines for acute coronary syndrome (ACS) recommend immediate aspirin (ASA) administration, an electrocardiogram (ECG) in less than 10 minutes, and a door-in to door-out (DIDO) time less than 30 minutes for interfacility transfer. We sought to determine if compliance is hindered when adults with suspected ACS present to pediatric facilities.

METHODS

Visits to the 2 tertiary care emergency departments of a pediatric healthcare system using an adult chest pain protocol were examined from October 2006 to September 2012. Patients older than 18 years with a diagnosis suggestive of ACS and an initial ECG interpretation were identified. Proportions of patients receiving ASA were calculated as well as median times to ECG and DIDO. Bivariate analysis of ECG and DIDO time and the proportion of the patients receiving ASA was conducted for ECG findings positive and negative for ACS.

RESULTS

One hundred thirteen patients were identified. Aspirin was administered in 69% of eligible cases. Electrocardiogram and DIDO times met recommended intervals in 42% (median, 12 minutes) and 5% (median, 59 minutes) of the patients, respectively. No significant differences between positive (22% of total) and negative (78% of total) ECG findings groups were detected in median DIDO time (57 vs 59 minutes, P = 0.99), time to ECG (14 vs 12 minutes, P = 0.45), or the proportion receiving ASA (84% vs 64%, P = 0.08).

CONCLUSIONS

Despite the use of an emergency department protocol, compliance with the American College of Cardiology Foundation/American Heart Association guidelines for adults with suspected ACS remained challenging at this pediatric center. The ECG findings did not seem to impact ASA administration, ECG time, or DIDO time.

Association between use of pre-hospital ECG and 30-day mortality: A large cohort study of patients experiencing chest pain

BACKGROUND

In the assessment of patients with chest pain, there is support for the use of pre-hospital ECG in the literature and in the care guidelines. Using propensity score methods, we aim to examine whether the mere acquisition of a pre-hospital ECG among patients with chest pain affects the outcome (30-day mortality).

METHODS

The association between pre-hospital ECG and 30-day mortality was studied in the overall cohort (n=13151), as well as in the one-to-one matched cohort with 2524 patients not examined with pre-hospital ECG and 2524 patients examined with pre-hospital ECG.

RESULTS

In the overall cohort, 21% (n=2809) did not undergo an ECG tracing in the pre-hospital setting. Among those who had pain during transport, 14% (n=1159) did not undergo a pre-hospital ECG while 32% (n=1135) of those who did not have pain underwent an ECG tracing. In the overall cohort, the OR for 30-day mortality in patients who had a pre-hospital ECG, as compared with those who did not, was 0.63 (95% CI 0.05-0.79; p<0.001). In the matched cohort, the OR was 0.65 (95% CI 0.49-0.85; p<0.001). Using the propensity score, in the overall cohort, the corresponding HR was 0.65 (95% CI 0.58-0.74).

CONCLUSION

Using propensity score methods, we provide real-world data demonstrating that the adjusted risk of death was considerably lower among the cases in whoma pre-hospital ECG was used. The PH-ECG is underused among patients with chest discomfort and the mere acquisition of a pre-hospital ECG may reduce mortality.

False Activations for ST-Segment Elevation Myocardial Infarction

First-medical-contact-to-device (FMC2D) times have improved over the past decade, as have clinical outcomes for patients presenting with ST-elevation myocardial infarction (STEMI). However, with improvements in FMC2D times, false activation of the cardiac catheterization laboratory (CCL) has become a challenging problem. The authors define false activation as any patient who does not warrant emergent coronary angiography for STEMI. In addition to clinical outcome measures for these patients, STEMI systems should collect data regarding the total number of CCL activations, the total number of emergency coronary angiograms, and the number revascularization procedures performed.

Telemedical support for prehospital Emergency Medical Service (TEMS trial): study protocol for a randomized controlled trial

Background

Increasing numbers of emergency calls, shortages of Emergency Medical Service (EMS), physicians, prolonged emergency response times and regionally different quality of treatment by EMS physicians require improvement of this system. Telemedical solutions have been shown to be beneficial in different emergency projects, focused on specific disease patterns. Our previous pilot studies have shown that the implementation of a holistic prehospital EMS teleconsultation system, between paramedics and experienced tele-EMS physicians, is safe and feasible in different emergency situations. We aim to extend the clinical indications for this teleconsultation system. We hypothesize that the use of a tele-EMS physician is noninferior regarding the occurrence of system-induced patient adverse events and superior regarding secondary outcome parameters, such as the quality of guideline-conforming treatment and documentation, when compared to conventional EMS-physician treatment.

Methods/design

Three thousand and ten patients will be included in this single-center, open-label, randomized controlled, noninferiority trial with two parallel arms. According to the inclusion criteria, all emergency cases involving adult patients who require EMS-physician treatment, excluding life-threatening cases, will be randomly assigned by the EMS dispatching center into two groups. One thousand five hundred and five patients in the control group will be treated by a conventional EMS physician on scene, and 1505 patients in the intervention group will be treated by paramedics who are concurrently instructed by the tele-EMS physicians at the teleconsultation center. The primary outcome measure will include the rate of treatment-specific adverse events in relation to the kind of EMS physician used. The secondary outcome measures will record the specific treatment-associated quality indicators.

Discussion

The evidence underlines the better quality of service using telemedicine networks between medical personnel and medical experts in prehospital emergency care, as well as in other medical areas. The worldwide unique EMS teleconsultation system in Aachen has been optimized and evaluated in pilot studies and subsequently integrated into routine use for a broad spectrum of indications. It has enabled prompt, safe and efficient patient treatment with optimized use of the “resource” EMS physician. There is, however, a lack of evidence as to whether the advantages of the teleconsultation system can be replicated in wider-ranging EMS-physician indications (excluding life-threatening emergency calls).

Trial registration

ClinicalTrials.gov, identifier: NCT02617875. Registered on 24 November 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1781-2) contains supplementary material, which is available to authorized users.

Acute chest pain fast track at the emergency department: who was misdiagnosed for acute coronary syndrome?

Background

Acute coronary syndrome (ACS) is a commonly treated disease in the emergency department (ED). Acute chest pain is a common presenting symptom of ACS. Acute chest pain fast track (ACPFT) is a triage to cover patients presenting with chest pain with the aims of early detection and treatment for ACS. This study aimed to assess the quality of the ACPFT with the aim of improving the quality of care for ACS patients.

Methods

This study was conducted at the ED in Mahidol University, Bangkok, Thailand. The inclusion criterion was patients presenting with acute chest pain at the ED. We retrospectively reviewed the medical records of all eligible patients. The primary outcomes of this study were to determine time from door to electrocardiogram and time from door to treatment (coronary angiogram with percutaneous coronary intervention or thrombolytic therapy in the case of ST elevation myocardial infarction). The outcome was compared between those who were in and not in the ACPFT.

Results

During the study period, there were 616 eligible patients who were divided into ACPFT (n=352 patients; 57.1%) and non-ACPFT (n=264 patients; 42.9%) groups. In the ACPFT group (n=352), 315 patients (89.5%) received an electrocardiogram within 10 minutes. The final diagnosis of ACS was made in 80 patients (22.7%) in the ACPFT group and 13 patients (4.9%) in the non-ACPFT group (P-value <0.01). After adjustment using multivariate logistic regression analysis, only epigastric pain was independently associated with being in the ACPFT group (adjusted odds ratio of 0.11; 95% confidence interval of 0.02, 0.56).

Conclusion

The ACPFT at the ED facilitated the prompt work-ups and intervention for ACS.