Prehospital 12-lead Electrocardiogram Research Articles

Machine learning with electrocardiograms to optimize mortality risk stratification in patients with suspected acute coronary syndrome

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Heart, Lung, and Blood Institute (NHLBI) and National Center for Advancing Translational Sciences (NCATS). Background The importance of risk stratification in patients with suspected acute coronary syndrome (ACS) extends beyond diagnosis and immediate treatment. It influences the precision of care delivery and the allocation of resources to those at highest risk of adverse events. Purpose We sought to evaluate the prognostic value of electrocardiogram (ECG) feature-based machine learning models to risk-stratify long-term mortality in those with suspected ACS. Methods This was a multicenter prospective observational cohort study of consecutive, non-traumatic patients evaluated at the emergency department for suspected ACS. The derivation cohort included 4,015 patients from a University Medical Center (age 59±16 years, 47% women, 80% training with 10-fold cross-validation and 20% testing). Ascertainment of all-cause death was based on numerous data sources, including the Centers for Disease Control and Prevention’s National Death Index registry. We trained six machine learning methods for survival analysis using 73 morphological ECG features from presenting prehospital 10-second 12-lead ECGs. We used predicted risk scores in a variational Bayesian Gaussian mixture model to define three risk groups corresponding to low, moderate, and high-risk and compared the resulting classification performance against the HEART score. The external testing cohort included 3,095 patients from a University (age 59±15 years, 44% women). Results The mortality rate was 20.3% in the derivation cohort after an average follow-up period of 3.53 years (IQR 1.75 - 5.32). Extra Survival Trees outperformed other forecasting models during cross-validation. In the internal testing cohort, the derived risk groups were significantly predictive of survival (Kaplan-Meier log-rank test statistic = 121.14, p<0.001), outperforming the classification performance using the HEART score (Figure 1). Our machine learning-based risk stratification model detected >90% of death events missed by low-risk HEART score (Figure 2). Ruling-out the low-risk group, it achieved a negative predictive value of 93.4% with a sensitivity of 85.9% (compared to 89.0% and 75.0%, respectively, for the HEART score). This classification performance generalized well to our external testing cohort. Compared to those in the low-risk group, patients at moderate (OR = 3.62 [1.35-9.74]) and high (OR = 6.12 [2.38-15.75]) risk had significantly higher odds of 30-day cardiovascular death (n=109, 3.5%). Conclusions Using only features from the 10-second 12-lead ECG, we derived and externally validated a machine learning model that stratifies the mortality risk of patients during long-term follow up. This model outperformed current standard of care based on the HEART score. Future work should validate the potential of this decision-support tool in influencing treatment plans and resource allocation.Figure 1.Clustering performanceFigure 2.Sankey diagram

The views, opinions and decision-making of UK-based paramedics on the use of pre-hospital 12-lead electrocardiograms in acute stroke patients: a qualitative interview study.

A qualitative exploration into the views, opinions and decision-making of paramedics involved in undertaking pre-hospital 12-lead electrocardiograms (PHECGs) for stroke patients was undertaken, in order to gain a deeper understanding of the clinical and occupational context that the paramedics work within, the acceptability of the paramedics in using PHECGs for stroke patients and the consequences and influences of their decision-making. Data were collected via semi-structured interviews and analysed using the framework method, with the underpinning theoretical framework of cognitive continuum theory. A purposive sample of 14 paramedics was recruited and interviewed. Five themes were generated from the analysis of the interviews: (1) 'time is brain': minimising delays and rapid transport to definitive care; (2) barriers and facilitators to undertaking PHECGs for stroke patients; (3) recognising and gaining cues; (4) maintaining patient dignity, self-protection and fully informed consent; and (5) education, experience and engagement with evidence. The study showed mixed views on the usefulness of PHECGs, but all participants agreed that PHECGs should not cause additional delays. Paramedic decision-making on recording PHECGs relies on intuitive and quasi-rational cognitive modes, and requires a number of clinical, logistical and ethical considerations. The findings suggest careful consideration is needed of the benefits and potential drawbacks of incorporating PHECGs into pre-hospital stroke care.

Spotlight on Research

Journal of Paramedic PracticeVol. 15, No. 1 Spotlight on ResearchSpotlight on ResearchPete GregoryPete GregoryAssociate Dean and Head of School of Allied Health and Midwifery, University of Wolverhampton, UKSearch for more papers by this authorPete GregoryPublished Online:13 Jan 2023https://doi.org/10.12968/jpar.2023.15.1.39AboutSectionsView articleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InEmail View article References Nehme E, Nehme Z, Cox S, Smith K. Outcomes of paediatric patients who are not transported to hospital by Emergency Medical Services: a data linkage study. Emerg Med J. https://doi.org/10.1136/emermed-2022-212350 Google ScholarMunro S, Cooke D, Joy M et al.. The pre-hospital 12-lead electrocardiogram is associated with longer delay and worse outcomes in patients presenting to emergency medical services with acute stroke: a linked cohort study. British Paramed J. 2022;7(2):16–23. https://doi.org/10.29045/14784726.2022.09.7.2.16 Crossref, Google Scholar FiguresReferencesRelatedDetails 2 January 2023Volume 15Issue 1ISSN (print): 1759-1376ISSN (online): 2041-9457 Metrics History Published online 13 January 2023 Published in print 2 January 2023 Information© MA Healthcare LimitedPDF download

Artificial intelligence-assisted remote detection of ST-elevation myocardial infarction using a mini-12-lead electrocardiogram device in prehospital ambulance care.

ObjectiveTo implement an all-day online artificial intelligence (AI)-assisted detection of ST-elevation myocardial infarction (STEMI) by prehospital 12-lead electrocardiograms (ECGs) to facilitate patient triage for timely reperfusion therapy.MethodsThe proposed AI model combines a convolutional neural network and long short-term memory (CNN-LSTM) to predict STEMI on prehospital 12-lead ECGs obtained from mini-12-lead ECG devices equipped in ambulance vehicles in Central Taiwan. Emergency medical technicians (EMTs) from the 14 AI-implemented fire stations performed the on-site 12-lead ECG examinations using the mini portable device. The 12-lead ECG signals were transmitted to the AI center of China Medical University Hospital to classify the recordings as “STEMI” or “Not STEMI”. In 11 non-AI fire stations, the ECG data were transmitted to a secure network and read by available on-line emergency physicians. The response time was defined as the time interval between the ECG transmission and ECG interpretation feedback.ResultsBetween July 17, 2021, and March 26, 2022, the AI model classified 362 prehospital 12-lead ECGs obtained from 275 consecutive patients who had called the 119 dispatch centers of fire stations in Central Taiwan for symptoms of chest pain or shortness of breath. The AI's response time to the EMTs in ambulance vehicles was 37.2 ± 11.3 s, which was shorter than the online physicians' response time from 11 other fire stations with no AI implementation (113.2 ± 369.4 s, P < 0.001) after analyzing another set of 335 prehospital 12-lead ECGs. The evaluation metrics including accuracy, precision, specificity, recall, area under the receiver operating characteristic curve, and F1 score to assess the overall AI performance in the remote detection of STEMI were 0.992, 0.889, 0.994, 0.941, 0.997, and 0.914, respectively. During the study period, the AI model promptly identified 10 STEMI patients who underwent primary percutaneous coronary intervention (PPCI) with a median contact-to-door time of 18.5 (IQR: 16–20.8) minutes.ConclusionImplementation of an all-day real-time AI-assisted remote detection of STEMI on prehospital 12-lead ECGs in the field is feasible with a high diagnostic accuracy rate. This approach may help minimize preventable delays in contact-to-treatment times for STEMI patients who require PPCI.

The pre-hospital 12-lead electrocardiogram is associated with longer delay and worse outcomes in patients presenting to emergency medical services with acute stroke: a linked cohort study.

To investigate the association between pre-hospital 12-lead electrocardiogram (PHECG) use in patients presenting to emergency medical services (EMS) with acute stroke, and clinical outcomes and system delays. Multi-centre linked cohort study. Patients with verified acute stroke admitted to hospital via EMS were identified through routinely collected hospital data and linked to EMS clinical records via EMS unique identifiers. Ordinal and logistic regression analyses were undertaken to analyse the relationship between having a PHECG and modified Rankin Scale (mRS); hospital mortality; pre-hospital time intervals; door-to-scan and door-to-needle times; and rates of thrombolysis. Of 1161 eligible patients admitted between 29 December 2013 and 30 January 2017, PHECG was performed in 558 (48%). PHECG was associated with an increase in mRS (adjusted odds ratio [aOR] 1.30, 95% confidence interval [CI] 1.01-1.66, p = 0.04) and hospital mortality (aOR 1.83, 95% CI 1.26-2.67, p = 0.002). There was no association between PHECG and administration of thrombolytic treatment (aOR 1.06, 95% CI 0.75-1.52, p = 0.73). Patients who had PHECG recorded spent longer under the care of EMS (median 49 vs 43 minutes, p = 0.006). No difference in times to receiving brain scan (median 28 with PHECG vs 29 minutes no PHECG, p = 0.32) or thrombolysis (median 46 vs 48 minutes, p = 0.37) were observed. The PHECG was associated with worse outcomes and longer delays in patients with acute ischaemic stroke.

Impact of Prehospital 12-Lead Electrocardiography and Destination Hospital Notification on Mortality in Patients With Chest Pain - A Systematic Review.

Background: To achieve early reperfusion therapy for ST-elevation myocardial infarction (STEMI), proper and prompt patient transportation and activation of the catheterization laboratory are required. We investigated the efficacy of prehospital 12-lead electrocardiogram (ECG) acquisition and destination hospital notification in patients with STEMI.Methods and Results: This is a systematic review of observational studies. We searched the PubMed database from inception to March 2020. Two reviewers independently performed literature selection. The critical outcome was short-term mortality. The important outcome was door-to-balloon (D2B) time. We used the GRADE approach to assess the certainty of the evidence. For the critical outcome, 14 studies with 29,365 patients were included in the meta-analysis. Short-term mortality was significantly lower in the group with prehospital 12-lead ECG acquisition and destination hospital notification than in the control group (odds ratio 0.72; 95% confidence interval [CI] 0.61–0.85; P<0.0001). For the important outcome, 10 studies with 2,947 patients were included in the meta-analysis. D2B time was significantly shorter in the group with prehospital 12-lead ECG acquisition and destination hospital notification than in the control group (mean difference −26.24; 95% CI −33.46, −19.02; P<0.0001).Conclusions: Prehospital 12-lead ECG acquisition and destination hospital notification is associated with lower short-term mortality and shorter D2B time than no ECG acquisition or no notification among patients with suspected STEMI outside of a hospital.

Present and Future Status of Cardiovascular Emergency Care System in Urban Areas of Japan - Importance of Prehospital 12-Lead Electrocardiogram.

Acute cardiovascular disease, such as acute myocardial infarction and aortic disease, can lead to a serious life-threatening state within minutes to hours, so early accurate diagnosis, and appropriate treatment without delay are essential. To provide high-quality and timely treatment, 24-h availability of medical staff and cardiologists, as well as a cardiac catheterization laboratory are needed. In Japan, the number of patients with acute cardiovascular disease is increasing with the aging population and westernization of lifestyle; however, workstyle reforms for physicians, including a policy to limit overtime work, have been legislated. Under these conditions, it is necessary to centralize hospitals that treat cardiovascular emergency diseases as high-volume centers and build a patient triage system for allocating patients before hospital arrival. The prehospital 12-lead electrocardiogram (ECG) plays a central role in prehospital diagnosis and triage, and its importance will increase in future. We discuss the current and future state of the cardiovascular emergency medical care system utilizing prehospital 12-lead ECG in urban areas of Japan.

Build a system to transmit prehospital 12-lead electrocardiogram linked with the ORION

Build a system to transmit prehospital 12-lead electrocardiogram linked with the ORION

Variant angina diagnosed on pre-hospital 12-lead electrocardiogram: A case report

Variant angina diagnosed on pre-hospital 12-lead electrocardiogram: A case report

The impact of pre-hospital 12-lead electrocardiogram and first contact by cardiologist in patients with ST-elevation myocardial infarction in Kanagawa, Japan

Background pre-hospital 12-lead electrocardiogram (ECG) by emergency medical service (EMS) personnel at the site of first medical contact (FMC) and the physician of first contact both play important roles in managing patients with ST-elevation myocardial infarction (STEMI). However, in Japan, pre-hospital 12-lead ECG is not routinely performed by EMS personnel at the site of FMC and the physician of first contact is not always a cardiologist.Methods from October 2015 to October 2019, 2035 consecutive STEMI patients transported from the field by ambulance were analyzed from the K-ACTIVE registry. Based on the presence (+) or absence (-) of pre-hospital 12-lead ECG / first contact by cardiologist, patients were divided into 4 groups (+/+, +/-, -/+, -/-). Patient characteristics, FMC to door time, door to device time and in-hospital mortality were compared.Results the numbers of patients in each group were as follows (+/+, n = 987; +/-, n = 211; -/+, n = 610; -/-, n = 227). For patient characteristics, there were significant differences in the prevalence of dyslipidemia and the presence of chest pain. The FMC to door time was similar (median value, +/+, 24 min; +/-, 25 min; -/+, 24 min; -/-, 24 min; p = 0.23). The door to device time was the shortest in the +/+ group (median value, +/+, 65 min; +/-, 80 min; -/+, 69 min; -/-, 88 min; p < 0.0001). Crude in-hospital mortality was the highest in the -/- group (+/+, 3.9%; +/-, 2.4%; -/+, 5.8%; -/-, 11.9%; p < 0.0001). After adjustment for age and sex, the adjusted odds ratios for in-hospital mortality were as follows [odds ratio (with 95% confidence interval) +/+, 0.33 [0.19-0.57]; +/-, 0.19 [0.07–0.52]; -/+, 0.49 [0.29–0.86]; -/-, 1 [reference)].Conclusion pre-hospital 12-lead ECG and the physician of first contact had a significant impact on the door to device time and in-hospital mortality. Continuous efforts should be made to improve acute management of STEMI.

Twelve-Lead Electrocardiogram Acquisition With a Patchy-Type Wireless Device in Ambulance Transport: Simulation-Based Randomized Controlled Trial

BackgroundCardiovascular disease is the leading cause of death worldwide. Early recognition, diagnosis, and reperfusion are the key elements of treatment for ST-segment elevation myocardial infarction. The absence of a prehospital 12-lead electrocardiogram (P12ECG) can cause definitive treatment delay and repeated transfer. Although guidelines highly recommend the measurement and transmission of P12ECG data, P12ECG use has not been widely established.ObjectiveThe aim of this study was to verify the time-efficiency and feasibility of the use of a patchy-type 12-lead ECG measuring and transmitting device (P-ECG) by an emergency medical technician (EMT) in an ambulance during patient transport.MethodsThis was a simulation-based prospective randomized crossover-controlled study that included EMTs. The participants were randomly assigned to one of two groups. Group A began the experiment with a conventional 12-lead ECG (C-ECG) device and then switched to the intervention device (P-ECG), whereas group B began the experiment with the P-ECG and then switched to the C-ECG. All simulations were performed inside an ambulance driving at 30 km/h. The time interval was measured from the beginning of ECG application to completion of sending the results. After the simulation, participants were administered the System Usability Scale questionnaire about usability of the P-ECG.ResultsA total of 18 EMTs were recruited for this study with a median age of 35 years. The overall interval time for the C-ECG was 254 seconds (IQR 247-270), whereas the overall interval time for the P-ECG was 130 seconds (IQR 112-150), with a significant difference (P<.001). Significant differences between the C-ECG and P-ECG were identified at all time intervals, in which the P-ECG device was significantly faster in all intervals, except for the preparation interval in which the C-ECG was faster (P=.03).ConclusionsPerformance of 12-lead ECG examination and transmission of the results using P-ECG are faster than those of C-ECG during ambulance transport. With the additional time afforded, EMTs can provide more care to patients and transport patients more rapidly, which may help reduce the symptoms-to-balloon time for patients with acute coronary syndrome.Trial RegistrationClinicalTrials.gov NCT04114760; https://www.clinicaltrials.gov/ct2/show/NCT04114760

Machine learning-based prediction of acute coronary syndrome using only the pre-hospital 12-lead electrocardiogram

Prompt identification of acute coronary syndrome is a challenge in clinical practice. The 12-lead electrocardiogram (ECG) is readily available during initial patient evaluation, but current rule-based interpretation approaches lack sufficient accuracy. Here we report machine learning-based methods for the prediction of underlying acute myocardial ischemia in patients with chest pain. Using 554 temporal-spatial features of the 12-lead ECG, we train and test multiple classifiers on two independent prospective patient cohorts (n = 1244). While maintaining higher negative predictive value, our final fusion model achieves 52% gain in sensitivity compared to commercial interpretation software and 37% gain in sensitivity compared to experienced clinicians. Such an ultra-early, ECG-based clinical decision support tool, when combined with the judgment of trained emergency personnel, would help to improve clinical outcomes and reduce unnecessary costs in patients with chest pain.

Prehospital electrocardiogram shortens ischaemic time in patients with ST-segment elevation myocardial infarction.

Total ischaemic time should be shortened as much as possible in patients with ST-segment elevation myocardial infarction (STEMI). This study evaluated whether prehospital 12-lead electrocardiogram (ECG) could shorten system delay in STEMI management. From November 2015 to November 2017, 15 ambulances equipped with X Series Monitor/ Defibrillator (Zoll Medical Corporation) were used in the catchment area of Queen Mary Hospital, Hong Kong. Prehospital ECG was performed for patients with chest pain; the data were tele-transmitted to attending emergency physicians at the Accident and Emergency Department (AED) for rapid assessment. Data from patients with STEMI who were transported by these 15 ambulances were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or who used self-arranged transport. Data were analysed from 197 patients with STEMI. The median patient delay for activation of the emergency response system was 90 minutes; 12% of patients experienced a delay of >12 hours. There was a significant difference in delay between patients transported by ambulance and those who used self-arranged transport (P<0.001). For system delay, the use of prehospital ECG shortened the median time from ambulance on scene to first ECG (P<0.001). When performed upon ambulance on scene, prehospital ECG was available 5 minutes earlier than if performed in ambulance compartment before departure. Use of prehospital ECG significantly shortened AED door-to-triage time, AED door-to-first AED ECG time, AED door-to-physician consultation time, and length of stay in the AED (P<0.001 for all comparisons). Prehospital ECG shortened ischaemic time prior to hospital admission.

PP11 The use of prehospital 12-lead electrocardiograms in acute stroke patients

BackgroundEmergency medical services (EMS) play a vital role in the recognition, management and transportation of acute stroke patients. UK guidelines recommend clinicians consider performing a prehospital 12-lead electrocardiogram (PHECG) in patients with suspected stroke, but this recommendation is based on expert consensus, rather than robust evidence.The aim of this study was to investigate the association between PHECG and modified Rankin scale (mRS). Secondary outcomes included in-hospital mortality, EMS and in-hospital time intervals and rates of thrombolysis received.MethodsA multicentre retrospective cohort study was undertaken.The data collection period spanned from 29/12/2013–30/01/2017. Participants were identified through secondary analysis of hospital data routinely collected as part of the Sentinel Stroke National Audit Programme (SSNAP) and linked to EMS clinical records (PCRs) via EMS incident number.ResultsPHECG was performed in 558 (48%) of study patients. PHECG was associated with an increase in mRS (aOR 1.30, 95% CI 1.01 to 1.66, p=0.04) and in-hospital mortality (aOR 1.83, 95% CI 1.26–2.67, p=0.002). There was no association between PHECG and administration of thrombolysis (aOR 1.06, 95% CI 0.75–1.52, p=0.73).Patients who had a PHECG recorded spent longer under the care of EMS (median 49 vs 43 min, p=0.007). No difference in times to receiving brain scan (Median 28 with PHECG vs 29 min no PHECG, p=0.32) or median door-to-needle time (median 46 min vs 48 min, p=0.37) were observed.ConclusionThis is the first study of its kind to investigate the association between PHECG and functional outcome in stroke patients attended by EMS. Although there are limitations in regard to the retrospective study design, the findings challenge current guideline recommendations regarding PHECG in patients with acute stroke.

A survey on prehospital 12-lead electrocardiogram recording and transmission in the Regional Medical Control Council

A survey on prehospital 12-lead electrocardiogram recording and transmission in the Regional Medical Control Council

Prehospital 12-lead electrocardiogram for patients with chest pain: a pilot study.

After ST-segment elevation myocardial infarction (STEMI), it is vital to shorten reperfusion time. This study examined data from a pilot project to shorten the door-to-balloon (D2B) time by using prehospital 12-lead electrocardiogram (ECG). Fifteen ambulances equipped with X Series® Monitor/Defibrillator (Zoll Medical Corporation) were deployed to the catchment area of Queen Mary Hospital, Hong Kong, from November 2015 to December 2016. For patients with chest pain, prehospital 12-lead ECG was performed and tele-transmitted to attending physicians at the accident and emergency department for immediate interpretation. The on-call cardiologist was called before patient arrival if STEMI was suspected. Data from this group of patients with STEMI were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or by self-arranged transport. From 841 patients with chest pain, 731 gave verbal consent and prehospital ECG was performed and transmitted. Of these, 25 patients with clinically diagnosed STEMI required emergency coronary angiogram with or without primary percutaneous coronary intervention. The mean D2B time for these 25 patients (93 minutes) was significantly shorter (P=0.003) than that for 58 patients with STEMI transported by ambulances without prehospital ECG (112 minutes) and that for 41 patients with STEMI with self-arranged transport (138 minutes). However, shorter reperfusion time was only recorded during daytime hours (08:00-17:59). No statistically significant difference in 30-day mortality was found. Prehospital ECG is technologically feasible in Hong Kong and shortens the D2B time. However, shorter reperfusion time was only recorded during daytime hours.

Detection of STEMI Using Prehospital Serial 12-Lead Electrocardiograms

Objective: Repeated or serial 12-lead electrocardiograms (ECGs) in the prehospital setting may improve management of patients with subtle ST-segment elevation (STE) or with a ST-segment elevation myocardial infarction (STEMI) that evolves over time. However, there is a minimal amount of scientific evidence available to support the clinical utility of this method. Our objective was to evaluate the use of serial 12-lead ECGs to detect STEMI in patients during transport in a Canadian emergency medical services (EMS) jurisdiction. Methods: We performed a retrospective study of suspected STEMI patients transported by EMS in the Chaudière-Appalaches region (Québec, Canada) between August 2006 and December 2013. Patients were monitored by a serial 12-lead ECG system where an averaged ECG was transmitted every 2 minutes. Following review by an emergency physician, ECGs were grouped as having either a persistent STE or a dynamic STE that evolved over time. Results: A total of 754 suspected STEMI patients were transported by EMS during the study period. Of these, 728 patients met eligibility criteria and were included in the analysis. A persistent STE was observed in 84.3% (614/728) of patients, while the remaining 15.7% (114/728) had a dynamic STE. Among those with dynamic STE, 11.1% (81/728) had 1 ST-segment change (41 no-STEMI to STEMI; 40 STEMI to no-STEMI) and 4.5% (33/728) had ≥ 2 ST-segment changes (17 no-STEMI to STEMI; 16 STEMI to no-STEMI). Overall, in 8.0% (58/728) of the cohort, STEMI was identified on a subsequent ECG following an initial no-STEMI ECG. Conclusions: Through recognition of transient ST-segment changes during transport via the prehospital serial 12-lead ECG system, STEMI was identified in 8% of suspected STEMI patients who had an initial no-STEMI ECG. Key words: electrocardiography; emergency medical services; ST-elevation myocardial infarction; prehospital dynamic ECG

Prehospital Modified HEART Score Predictive of 30-Day Adverse Cardiac Events

A retrospective cohort study of patients with chest pain transported by two county-based Emergency Medical Service (EMS) agencies to a tertiary care center was conducted. Adults without ST-elevation myocardial infarction (STEMI) were included. Inter-facility transfers and those without a prehospital 12-lead ECG or an ED troponin measurement were excluded. Modified HEART scores were calculated by study investigators using a standardized data collection tool for each patient. All MACE (death, myocardial infarction [MI], or coronary revascularization) were determined by record review at 30 days. The sensitivity and negative predictive values (NPVs) for MACE at 30 days were calculated. Over the study period, 794 patients met inclusion criteria. A MACE at 30 days was present in 10.7% (85/794) of patients with 12 deaths (1.5%), 66 MIs (8.3%), and 12 coronary revascularizations without MI (1.5%). The modified HEART score identified 33.2% (264/794) of patients as low risk. Among low-risk patients, 1.9% (5/264) had MACE (two MIs and three revascularizations without MI). The sensitivity and NPV for 30-day MACE was 94.1% (95% CI, 86.8-98.1) and 98.1% (95% CI, 95.6-99.4), respectively. Prehospital modified HEART scores have a high NPV for MACE at 30 days. A study in which prehospital providers prospectively apply this decision aid is warranted. Stopyra JP , Harper WS , Higgins TJ , Prokesova JV , Winslow JE , Nelson RD , Alson RL , Davis CA , Russell GB , Miller CD , Mahler SA . Prehospital modified HEART score predictive of 30-day adverse cardiac events. Prehosp Disaster Med. 2018;33(1):58-62.

Implementation of an ST-Segment Elevation Myocardial Infarction Bypass Protocol in the Northern United Arab Emirates.

Objective:The aim was to evaluate the translation of an ST-segment elevation myocardial infarction (STEMI) bypass protocol to the outcomes of patients with acute coronary syndrome in the Emirate of Ras al-Khaimah in the United Arab Emirates (UAE).Methods:A prospective cohort study was conducted, which included all patients who had a prehospital 12-lead electrocardiogram (ECG) performed by ambulance crews. Analysis of those who were identified as having STEMI and who subsequently underwent percutaneous coronary intervention (PCI) was performed.Results:A total of 152 patients had a 12-lead ECG performed during the pilot study period (February 24, 2016–August 31, 2016) with 118 included for analysis. Mean patient age was 52 years. There were 87 male (74%) and 31 female (26%) patients. Twenty-nine patients suffered a STEMI, and data were available for 11 who underwent PCI. There was no mortality, and no major adverse cardiac events were reported. The median door-to-balloon (D2B) time was 73 min (range 48–124), and 81% of patients had a D2B time < 90 min. Discharge data were available for six patients: All were discharged home with no impediments to rehabilitation.Conclusion:This pilot study has demonstrated agreement with the existing literature surrounding prehospital ECG and PCI activation in an unstudied STEMI population and in a novel clinical setting. It has demonstrated a D2B time of < 90 min in over 80% of STEMI patients, and a faster mean D2B time than self-presentations (mean 77 min vs. 113 min), with no associated mortality or major adverse cardiac events.

MP028: Dynamic changes of prehospital serial 12-lead electrocardiogram for remote diagnosis of suspected ST-segment elevation myocardial infarction

Introduction: Accurate and efficient interpretation of prehospital 12-lead electrocardiogram (ECG) in patients with suspected ST-segment elevation myocardial infarction (STEMI) can improve outcomes, especially in rural regions. In the Chaudière-Appalaches region, Quebec, a prehospital serial 12-lead ECG monitoring system is used for remote interpretation of ECG abnormalities by emergency physicians via a telemedicine platform, the Unité de Coordination Clinique des Soins Préhospitaliers d'Urgence (UCCSPU). The objective of the study was to evaluate the use of serial monitoring of dynamic ECG changes in patients with suspected STEMI during emergency medical services (EMS) transport. Methods: A retrospective cohort study with suspected STEMI patients monitored with prehospital serial ECGs was performed from August 2006 to December 2013. The data was extracted from UCCSPU clinical databases and verified by an emergency physician supervisor. During EMS transport, the serial ECG monitoring system automatically produced and transmitted every 2 minutes a 12-lead ECG without artefacts. STEMI criteria were based on the Third Universal Definition of Myocardial Infarction. Dynamic ECG change was defined as an ST-segment elevation or depression that meets diagnostic criteria (eg. initial non STEMI (NSTEMI) changing to STEMI and vice versa). Results: Among the 752 patients identified with suspected STEMI, 728 (96.8%) were included in the study due to missing data. The majority (614/728; 84.3%) had a consistent ST segment without significant dynamic changes throughout transport, of which 521 were identified as STEMI and 93 as NSTEMI. The remaining 114 patients (15.7%) had dynamic ECG changes: 41 (36%) evolved from NSTEMI to STEMI, 40 (35.1%) changed from STEMI to NSTEMI, and 33 (28.9%) had more than one dynamic ST-segment change. Overall, 59 patients (8.1%) had a final STEMI ECG diagnosis after an initial NSTEMI ECG interpretation. Conclusion: In this study, the serial ECG system enabled the remote diagnosis of STEMI in 8.1% of patients during EMS transport following an initial NSTEMI diagnosis. Serial monitoring of dynamic changes can allow for more rapid diversion to primary percutaneous coronary intervention facilities, potentially improving patient outcomes. Further studies are needed to evaluate the clinical impact, and costs and benefits of implementing this technology.