Association Between Prehospital Time Intervals and ST-Elevation Myocardial Infarction System Performance

Prehospital Time Disparities for Rural Patients with Suspected STEMI

BACKGROUND

Rural patients with ST-elevation myocardial infarction (STEMI) may be less likely to receive prompt reperfusion therapy. This study's primary objective was to compare rural versus urban time intervals among a national cohort of prehospital patients with STEMI.

METHODS

The ESO Data Collaborative (Austin, TX), containing records from 1,366 emergency medical services agencies, was queried for adult 9-1-1 responses with suspected STEMI from 1/1/2018-12/31/2019. The scene address for each encounter was classified as either urban or rural using the 2010 US Census Urban Area Zip Code Tabulation Area relationship. The primary outcome was total EMS interval (9-1-1 call to hospital arrival); a key secondary outcome was the proportion of responses that had EMS intervals under 60 minutes. Generalized estimating equations were used to determine whether rural versus urban differences in interval outcomes occurred when adjusting for loaded mileage (distance from scene to hospital) and patient and clinical encounter characteristics.

RESULTS

Of 15,915,027 adult 9-1-1 transports, 23,655 records with suspected STEMI were included in the analysis. Most responses (91.6%, n = 21,661) occurred in urban settings. Median EMS interval was 37.6 minutes (IQR 30.0-48.0) in urban settings compared to 57.0 minutes (IQR 46.5-70.7) in rural settings (p < 0.01). Urban responses more frequently had EMS intervals <60 minutes (89.5%, n = 19,130), compared to rural responses (55.5%, n = 1,100, p < 0.01). After adjusting for loaded mileage, age, sex, race/ethnicity, abnormal vital signs, pain assessment, aspirin administration, and IV/IO attempt, rural location was associated with a 5.8 (95%CI 4.2-7.4) minute longer EMS interval than urban, and rural location was associated with a reduced chance of achieving EMS interval < 60 minutes (OR 0.40; 95%CI 0.33-0.49) as compared to urban location.

CONCLUSION

In this large national sample, rural location was associated with significantly longer EMS interval for patients with suspected STEMI, even after accounting for loaded mileage.

Prehospital time for patients with acute cardiac complaints: A rural health disparity

OBJECTIVE

Delays in care for patients with acute cardiac complaints are associated with increased morbidity and mortality. The objective of this study was to quantify rural and urban differences in prehospital time intervals for patients with cardiac complaints.

METHODS

The ESO Data Collaborative dataset consisting of records from 1332 EMS agencies was queried for 9-1-1 encounters with acute cardiac problems among adults (age ≥ 18) from 1/1/2013-6/1/2018. Location was classified as rural or urban using the 2010 United States Census. The primary outcome was total prehospital time. Generalized estimating equations evaluated differences in the average times between rural and urban encounters while controlling for age, sex, race, transport mode, loaded mileage, and patient stability.

RESULTS

Among 428,054 encounters, the median age was 62 (IQR 50-75) years with 50.7% female, 75.3% white, and 10.3% rural. The median total prehospital, response, scene, and transport times were 37.0 (IQR 29.0-48.0), 6.0 (IQR 4.0-9.0), 16.0 (IQR 12.0-21.0), and 13.0 (IQR 8.0-21.0) minutes. Rural patients had an average total prehospital time that was 16.76 min (95%CI 15.15-18.38) longer than urban patients. After adjusting for covariates, average total time was 5.08 (95%CI 4.37-5.78) minutes longer for rural patients. Average response and transport time were 4.36 (95%CI 3.83-4.89) and 0.62 (95%CI 0.33-0.90) minutes longer for rural patients. Scene time was similar in rural and urban patients (0.09 min, 95%CI -0.15-0.33).

CONCLUSION

Rural patients with acute cardiac complaints experienced longer prehospital time than urban patients, even after accounting for other key variables, such as loaded mileage.

Training Non-Cardiologists Could Improve the Treatment Results of ST Elevation Myocardial Infarction

Fundamento

De acordo com a Organização Mundial da Saúde, países emergentes terão um crescimento considerável no número de ataques cardíacos e mortes relacionadas. Um dos principais problemas médicos no Brasil é a mortalidade causada por infarto agudo do miocárdio com supra de ST (IAMCSST). A Sociedade de Cardiologia do Estado de São Paulo nunca treinou não-cardiologistas para atendimentos de emergência. Os pacientes normalmente buscam ajuda em prontos-socorros, em vez de chamar a ambulância.

Objetivo

Nosso objetivo foi reduzir as taxas de mortalidade hospitalar causada por infarto agudo do miocárdio ao treinar profissionais da emergência na cidade de São Paulo.

Métodos

Utilizamos um programa de treinamento para as equipes de cinco hospitais com > 100 pacientes internados com IAMCSST por ano, e pelo menos 15% de mortes hospitalares relacionadas ao IAMCSST. Realizamos treinamentos online, organizamos de dois a quatro eventos para até 400 participantes, fizemos folders e panfletos informativos. A análise estatística utilizou o teste para comparação de duas proporções, com p <0,05.

Resultados

Quase 200 médicos e 350 enfermeiros participaram de pelo menos um treinamento de maio de 2010 até dezembro de 2013. Inicialmente, muitos médicos da emergência não reconheciam um infarto agudo do miocárdio no eletrocardiograma, mas a tele-ecocardiografia é usada em alguns departamentos da emergência para determinar o diagnóstico. A taxa de mortalidade nos cinco hospitais caiu de 25,6%, em 2009, para 18,2%, em 2010 (p=0,005). Depois da conclusão do período de treinamento, as mortes relacionadas ao IAMCSST em todos os hospitais públicos de São Paulo diminuíram de 14,31%, em 2009, para 11,25%, em 2014 (p<0,0001).

Conclusão

Mesmo programas simplificados de treinamento de pessoal da emergência pode reduzir muito as taxas de morte por infarto agudo do miocárdio em países em desenvolvimento.

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.

Impact of emergency medical service delays on time to reperfusion and mortality in STEMI

Objectives

To explore the relationship between emergency medical service (EMS) delay time, overall time to reperfusion and clinical outcome in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).

Methods

This was a retrospective observational study of 2976 patients with STEMI who presented to EMS and underwent PPCI between January 2014 and December 2017. We performed multivariable logistic models to assess the relationship between EMS delay time and 30-day mortality and to identify factors associated with system delay time.

Results

EMS delay time accounted for the first half of total system delay (median=59 min (IQR=48–77)). Compared with those who survived, those who died had longer median EMS delay times (59 (IQR=11–74) vs 74 (IQR=57–98), p<0.001). EMS delay time was independently associated with a higher risk of mortality (adjusted OR 1.20; 95% CI 1.02 to 1.40, for every 30 min increase), largely driven by complicated patients with cardiogenic shock or cardiac arrest. Independent predictors of longer EMS delay times were older age, women, cardiogenic shock, cardiac arrest, prehospital notification and intensive care management. Although longer EMS delay times were associated with shorter door-to-balloon times, total system delay times increased with increasing EMS delay times.

Conclusion

Increasing EMS delay times, particularly those result from haemodynamic complications, increase total time to reperfusion and are associated with 30-day mortality after STEMI. All efforts should be made to monitor and reduce EMS delay times for timely reperfusion and better outcome.

Barriers to Physical Activity Among Emergency Medical Services Professionals

BACKGROUND

Emergency medical services (EMS) professionals demonstrate low adherence to physical activity guidelines and experience a high prevalence of obesity and incidence of injury. The authors investigate the barriers to participating in physical activity among EMS professionals.

METHODS

The EMS professionals employed by 15 North Carolina EMS agencies were surveyed with validated items. Multivariable logistic regression models were used to estimate the odds (odds ratio, 95% confidence interval) of not meeting physical activity guidelines for each barrier to being active, controlling for age, sex, body mass index category, race/ethnicity, certification and education level, and work hours.

RESULTS

A total of 1367 EMS professionals were invited to participate, and 359 complete responses were recorded. Half of the respondents (48.2%) met Centers for Disease Control and Prevention physical activity guidelines. According to standard body mass index categories, 55.9% were obese. There were increased odds of not meeting physical activity guidelines for the following barriers: lack of energy (5.32, 3.12-9.09), lack of willpower (4.31, 2.57-7.22), lack of time (3.55, 2.12-5.94), social influence (3.02, 1.66-5.48), and lack of resources (2.14, 1.12-4.11). The barriers of fear of injury and lack of skill were not associated with meeting physical activity guidelines.

CONCLUSION

Half of EMS professionals did not meet physical activity guidelines, and the majority were obese. Significant associations exist between several modifiable barriers and not meeting physical activity guidelines.

Primary Percutaneous Coronary Intervention Facility Hospitals and Easy Access Can Affect the Outcomes of ST-Segment Elevation Myocardial Infarction Patients

BACKGROUND

The reperfusion therapy using primary percutaneous coronary intervention (PPCI) in ST-segment elevation myocardial infarction (STEMI) is known to give a better result than fibrinolytic therapy. The fast access to PPCI will improve hospital outcome. We believe that patient access to PPCI facility would have improved due to enhanced public awareness and expanding evidenced-based health provision.

METHODS

This is a single-center retrospective study to analyze and compare data for STEMI patients. Patients were transferred to our hospital during the year 2010. Group l comprised 223 patients. Group 2 comprised 288 patients. Group 2 patients were those treated between August 2014 and August 2015. We compared their demographic and baseline characteristics, patients' access to the hospital, reasons for no access, and hospital mortality for the two groups.

RESULTS

Among the 288 patients in Group 2, 247 patients (85%) were males with an average age of 57 years, 49% were diabetics, 48% were hypertensive, 48% were smokers, and 27% were obese. These were not different in Group 1. In Group 2, 164 patients (57%) only had access to PPCI compared to 56% in Group 1 (P = 0.536-NS). In G2, the main reasons for no PPCI were late presentation in 47% versus 53% in Group 1; P = 0.34 NS. In Group 2, 27% were due to thrombolysis versus 17% in Group 1 (P = 0.11 NS). Hospital mortality in Group 2 was 4% in those treated with PPCI compared to 2.3% in Group 1 (P = 0.522-NS). Mortality in patients who did not receive PPCI in Group 2 was 8% compared to 11.3% in Group 1 (P = 0.49-NS). Females in Group 2 have about 3 times higher mortality. Patients treated for STEMI in the last 12 months at King Abdulaziz Cardiac Center still have relatively low access to PPCI due mainly to persistent pattern of late presentation and prior thrombolysis, which reflect apparent lack of direct access to hospitals with PPCI facilities.

CONCLUSION

Comparing the two periods, there was no change in cardiology practice. The low access to PPCI was mainly due to late presentation and prior thrombolysis. Hospital mortality rate for patients treated with PPCI remained low during the two era. This seemingly relates to both lack of public awareness and health provision factors in PPCI organizations.

Development and testing of Australian prehospital care quality indicators: study protocol

INTRODUCTION

Historically, ambulance services were established to provide rapid transport of patients to hospital. Contemporary prehospital care involves provision of sophisticated 'mobile healthcare' to patients across the lifespan presenting with a range of injuries or illnesses of varying acuity. Because of its young age, the paramedicine profession has until recently experienced a lack of research capacity which has led to paucity of a discipline-specific, scientific evidence-base. Therefore, the performance and quality of ambulance services has traditionally been measured using simple, evidence-poor indicators forming a deficient reflection of the true quality of care and providing little direction for quality improvement efforts. This paper reports the study protocol for the development and testing of quality indicators (QIs) for the Australian prehospital care setting.

METHODS AND ANALYSIS

This project has three phases. In the first phase, preliminary work in the form of a scoping review was conducted which provided an initial list of QIs. In the subsequent phase, these QIs will be developed by aggregating them and by performing related rapid reviews. The summarised evidence will be used to support an expert consensus process aimed at optimising the clarity and evaluating the validity of proposed QIs. Finally, in the third phase those QIs deemed valid will be tested for acceptability, feasibility and reliability using mixed research methods. Evidence-based indicators can facilitate meaningful measurement of the quality of care provided. This forms the first step to identify unwarranted variation and direction for improvement work. This project will develop and test quality indicators for the Australian prehospital care setting.

ETHICS AND DISSEMINATION

This project has been approved by the University of Adelaide Human Research Ethics Committee. Findings will be disseminated by publications in peer-reviewed journals, presentations at appropriate scientific conferences, as well as posts on social media and on the project's website.

The Effect of Lights and Sirens on Critical Care Transport Time

BACKGROUND

In the prehospital setting, the use of ambulance lights and sirens (L&S) has been found to result in minor decreases in transport times, but has not been studied in interfacility transportation.

OBJECTIVE

The objective of this study was to evaluate the indications for L&S and the impact of L&S on transport times in interfacility critical care transport.

METHODS

We performed a retrospective analysis using administrative data from a large, urban critical care transportation organization. The indications for L&S were assessed and the transport times with and without L&S were compared using distance matching for common transport routes. Median times were compared for temporal subgroups.

RESULTS

L&S were used in 7.3% of transports and were most strongly associated with transport directly to the operating room (odds ratio 15.8; 95% confidence interval 6.32-39.50; p < 0.001). The timing of the transport was not associated with L&S use. For all transports, there was a significant decrease in the transport time using L&S, with a median of 8 min saved, corresponding to 19.5% of the overall transportation time without L&S (33 vs. 41 min; p < 0.001). The reduction in transport times was consistent across all temporal subgroups, with a greater time reduction during rush hour transports.

CONCLUSIONS

The use of L&S during interfacility critical care transport was associated with a statistically significant time reduction in this urban, single-system retrospective analysis. Although the use of L&S was not associated with rush-hour transports, the greatest time reduction was associated with L&S transport during these hours.

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.

Indicators to measure prehospital care quality: a scoping review

OBJECTIVE

The purpose of this scoping review was to locate, examine and describe the literature on indicators used to measure prehospital care quality.

INTRODUCTION

The performance of ambulance services and quality of prehospital care has traditionally been measured using simple indicators, such as response time intervals, based on low-level evidence. The discipline of paramedicine has evolved significantly over the last few decades. Consequently, the validity of utilizing such measures as holistic prehospital care quality indicators (QIs) has been challenged. There is growing interest in finding new and more significant ways to measure prehospital care quality.

INCLUSION CRITERIA

This scoping review examined the concepts of prehospital care quality and QIs developed for ambulance services. This review considered primary and secondary research in any paradigm and utilizing any methods, as well as text and opinion research.

METHODS

Joanna Briggs Institute methodology for conducting scoping reviews was employed. Separate searches were conducted for two review questions; review question 1 addressed the definition of prehospital care quality and review question 2 addressed characteristics of QIs in the context of prehospital care. The following databases were searched: PubMed, CINAHL, Embase, Scopus, Cochrane Library and Web of Science. The searches were limited to publications from January 1, 2000 to the day of the search (April 16, 2017). Non-English articles were excluded. To supplement the above, searches for gray literature were performed, experts in the field of study were consulted and applicable websites were perused.

RESULTS

Review question 1: Nine articles were included. These originated mostly from England (n = 3, 33.3%) and the USA (n = 3, 33.3%). Only one study specifically aimed at defining prehospital care quality. Five articles (55.5%) described attributes specific to prehospital care quality and four (44.4%) articles considered generic healthcare quality attributes to be applicable to the prehospital context. A total of 17 attributes were identified. The most common attributes were Clinical effectiveness (n = 17, 100%), Efficiency (n = 7, 77.8%), Equitability (n = 7, 77.8%) and Safety (n = 6, 66.7%). Timeliness and Accessibility were referred to by four and three (44.4% and 33.3%) articles, respectively.Review question 2: Thirty articles were included. The predominant source of articles was research literature (n = 23; 76.7%) originating mostly from the USA (n = 13; 43.3%). The most frequently applied QI development method was a form of consensus process (n = 15; 50%). A total of 526 QIs were identified. Of these, 283 (53.8%) were categorized as Clinical and 243 (46.2%) as System/Organizational QIs. Within these categories respectively, QIs related to Out-of-hospital cardiac arrest (n = 57; 10.8%) and Time intervals (n = 75; 14.3%) contributed the most. The most commonly addressed prehospital care quality attributes were Appropriateness (n = 250, 47.5%), Clinical effectiveness (n = 174, 33.1%) and Accessibility (n = 124, 23.6%). Most QIs were process indicators (n = 386, 73.4%).

CONCLUSION

Whilst there is paucity in research aiming to specifically define prehospital care quality, the attributes of generic healthcare quality definitions appear to be accepted and applicable to the prehospital context. There is growing interest in developing prehospital care QIs. However, there is a need for validation of existing QIs and de novo development addressing broader aspects of prehospital care.

Emergency medical service delays in ST-elevation myocardial infarction: a meta-analysis

OBJECTIVES

To evaluate emergency medical services (EMS) delays and their impact on time to treatment and mortality in patients with ST-elevation myocardial infarction (STEMI).

METHOD

We collected data on EMS time intervals from published studies across five electronic databases. The primary EMS interval was the time in minutes between first medical contact and arrival at hospital door (FMC-to-door time). Secondary intervals were other components of EMS delay. Weighted means were measured using random-effects models. Meta-regression was used to identify factors associated with EMS delays and to assess the impact of EMS delay on the proportion of patients treated within90 min and mortality.

RESULTS

Two independent reviewers included 100 studies (125 343 patients) conducted in 20 countries. The weighted mean FMC-to-door time was 41 min (n=101 646; 95% CI 39 to 43, range 21-88). However, substantial heterogeneity was observed with each interval, which could be explained by region and urban classification, distance to hospital and method of ECG interpretation. In a meta-regression adjusted for door-to-balloon time, a 10 min increase in FMC-to-door time was associated with a 10.6% (95% CI 7.6% to 13.5%; p<0.001) reduction in the proportion of patients treated within 90 min. Shorter EMS delay was significantly associated with lower short-term mortality in patients receiving prehospital thrombolysis (p=0.018).

CONCLUSION

EMS delays account for half of the total system delay in STEMI. There is a fourfold global variation in EMS delays, which are not completely explained by differences in system characteristics. Reducing unexplained variation could yield improvements in the time to treatment and outcome of STEMI patients.

PROSPERO REGISTRATION NUMBER

CRD42017074118.

Prognostic significance of emergency department bypass in stable and unstable patients with ST-segment elevation myocardial infarction

Background:

In ST-segment elevation myocardial infarction (STEMI) patients treated with percutaneous coronary intervention, direct transport from the scene to the catheterisation laboratory bypassing the emergency department has been shown to shorten times to reperfusion. The aim of this study was to investigate the effects of emergency department bypass on mortality in both haemodynamically stable and unstable STEMI patients.

Methods:

The analysis is based on a large cohort of STEMI patients prospectively included in the German multicentre Feedback Intervention and Treatment Times in ST-Elevation Myocardial Infarction (FITT-STEMI) trial.

Results:

Out of 13,219 STEMI patients who were brought directly from the scene by emergency medical service transportation and were treated with percutaneous coronary intervention, the majority were transported directly to the catheterisation laboratory bypassing the emergency department (n=6740, 51% with emergency department bypass). These patients had a significantly lower in-hospital mortality than their counterparts with no emergency department bypass (6.2% vs. 10.0%, P<0.0001). The reduced mortality related to emergency department bypass was observed in both stable (n=11,594, 2.8% vs. 3.8%, P=0.0024) and unstable patients presenting with cardiogenic shock (n=1625, 36.3% vs. 46.2%, P<0.0001). Regression models adjusted for the Thrombolysis In Myocardial Infarction (TIMI) risk score consistently confirmed a significant and independent predictive effect of emergency department bypass on survival in the total study population (odds ratio 0.64, 95% confidence interval 0.56–0.74, P<0.0001) and in the subgroup of shock patients (OR 0.69, 95% CI 0.54–0.88, P=0.0028).

Conclusion:

In STEMI patients, emergency department bypass is associated with a significant reduction in mortality, which is most pronounced in patients presenting with cardiogenic shock. Our data encourage treatment protocols for emergency department bypass to improve the survival of both haemodynamically stable patients and, in particular, unstable patients.

Clinical Trial Registration: NCT00794001

ClinicalTrials.gov: NCT00794001

A US National Study of the Association Between Income and Ambulance Response Time in Cardiac Arrest

IMPORTANCE

Emergency medical services (EMS) provide critical prehospital care, and disparities in response times to time-sensitive conditions, such as cardiac arrest, may contribute to disparities in patient outcomes.

OBJECTIVES

To investigate whether ambulance 9-1-1 times were longer in low-income vs high-income areas and to compare response times with national benchmarks of 4, 8, or 15 minutes across income quartiles.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cross-sectional study was performed of the 2014 National Emergency Medical Services Information System data in June 2017 using negative binomial and logistic regressions to examine the association between zip code-level income and EMS response times. The study used ambulance 9-1-1 response data for out-of-hospital cardiac arrest from 46 of 50 state repositories (92.0%) in the United States. The sample included 63 600 cardiac arrest encounters of patients who did not die on scene and were transported to the hospital.

MAIN OUTCOMES AND MEASURES

Four time measures were examined, including response time, on-scene time, transport time, and total EMS time. The study compared response times with EMS response time benchmarks for responding to cardiac arrest calls within 4, 8, and 15 minutes.

RESULTS

The study sample included 63 600 cardiac arrest encounters of patients (mean [SD] age, 60.6 [19.0] years; 57.9% male), with 37 550 patients (59.0%) from high-income areas and 8192 patients (12.9%) from low-income areas. High-income areas had greater proportions of white patients (70.1% vs 62.2%), male patients (58.8% vs 54.1%), privately insured patients (29.4% vs 15.9%), and uninsured patients (15.3% vs 7.9%), while low-income areas had a greater proportion of Medicaid-insured patients (38.3% vs 15.8%). The mean (SD) total EMS time was 37.5 (13.6) minutes in the highest zip code income quartile and 43.0 (18.8) minutes in the lowest. After controlling for urban zip code, weekday, and time of day in regression analyses, total EMS time remained 10% longer (95% CI, 9%-11%; P < .001), translating to 3.8 minutes longer in the poorest zip codes. The EMS response time to patients in high-income zip codes was more likely to meet 8-minute and 15-minute cutoffs compared with low-income zip codes.

CONCLUSIONS AND RELEVANCE

Patients with cardiac arrest from the poorest neighborhoods had longer EMS times compared with those from the wealthiest, and response times were less likely to meet national benchmarks in low-income areas, which may lead to increased disparities in prehospital delivery of care over time.

Diagnostic Accuracy of Prehospital Tele-Electrocardiography in Acute Coronary Syndrome

BACKGROUND

Tele-electrocardiography (tele-ECG) is a powerful ally in the screening of acute ischemic lesions.

INTRODUCTION

Evidence that confirms the correlation between the diagnosis of acute coronary syndrome (ACS) determined in the prehospital setting and the confirmation of the diagnosis in the hospital setting is scarce. This study compares the presumed diagnosis of ACS in the prehospital setting based on electrocardiographic changes, such as ST-segment deviation, with the diagnosis confirmed in a hospital setting.

MATERIALS AND METHODS

Retrospective, cross-sectional analysis of medical records of patients who sought emergency ambulance services of a distinguished public healthcare service in the city of Porto Alegre from September 2013 to August 2014. Data were collected from tele-ECG recordings and medical records available at the database of the Secretary of Health. The study was based on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.

RESULTS

Among the 1,338 prehospital examinations performed, a total of 250 admissions in tertiary hospitals were registered. There was a significant agreement (p < 0.01) of 71% of the electrocardiographic changes identified in the prehospital setting with the diagnosis of ACS confirmed in the hospital setting. These changes were more prevalent in men (p = 0.048) and in patients aged 60 years or older (p = 0.006).

DISCUSSION

The tele-ECG allows the early diagnosis of ACS, reducing the delay to definitive treatment, be it reperfusion, chemical, or mechanical therapy.

CONCLUSIONS

Seventy-two percent of the prehospital diagnosis of ACS based on electrocardiographic changes was later confirmed in the hospital setting.

Quality Indicators for Evaluating Prehospital Emergency Care: A Scoping Review

Introduction Historically, the quality and performance of prehospital emergency care (PEC) has been assessed largely based on surrogate, non-clinical endpoints such as response time intervals or other crude measures of care (eg, stakeholder satisfaction). However, advances in Emergency Medical Services (EMS) systems and services world-wide have seen their scope and reach continue to expand. This has dictated that novel measures of performance be implemented to compliment this growth. Significant progress has been made in this area, largely in the form of the development of evidence-informed quality indicators (QIs) of PEC. Problem Quality indicators represent an increasingly popular component of health care quality and performance measurement. However, little is known about the development of QIs in the PEC environment. The purpose of this study was to assess the development and characteristics of PEC-specific QIs in the literature.

METHODS

A scoping review was conducted through a search of PubMed (National Center for Biotechnology Information, National Institutes of Health; Bethesda, Maryland USA); EMBase (Elsevier; Amsterdam, Netherlands); CINAHL (EBSCO Information Services; Ipswich, Massachusetts USA); Web of Science (Thomson Reuters; New York, New York USA); and the Cochrane Library (The Cochrane Collaboration; Oxford, United Kingdom). To increase the sensitivity of the literature, a search of the grey literature and review of select websites was additionally conducted. Articles were selected that proposed at least one PEC QI and whose aim was to discuss, analyze, or promote quality measurement in the PEC environment.

RESULTS

The majority of research (n=25 articles) was published within the last decade (68.0%) and largely originated within the USA (68.0%). Delphi and observational methodologies were the most commonly employed for QI development (28.0%). A total of 331 QIs were identified via the article review, with an additional 15 QIs identified via the website review. Of all, 42.8% were categorized as primarily Clinical, with Out-of-Hospital Cardiac Arrest contributing the highest number within this domain (30.4%). Of the QIs categorized as Non-Clinical (57.2%), Time-Based Intervals contributed the greatest number (28.8%). Population on Whom the Data Collection was Constructed made up the most commonly reported QI component (79.8%), followed by a Descriptive Statement (63.6%). Least reported were Timing of Data Collection (12.1%) and Timing of Reporting (12.1%). Pilot testing of the QIs was reported on 34.7% of QIs identified in the review.

CONCLUSION

Overall, there is considerable interest in the understanding and development of PEC quality measurement. However, closer attention to the details and reporting of QIs is required for research of this type to be more easily extrapolated and generalized. Howard I , Cameron P , Wallis L , Castren M , Lindstrom V . Quality indicators for evaluating prehospital emergency care: a scoping review. Prehosp Disaster Med. 2018;33(1):43-52.

Characteristics of ST Elevation Myocardial Infarction Patients Who Do Not Undergo Percutaneous Coronary Intervention After Prehospital Cardiac Catheterization Laboratory Activation

OBJECTIVES

To assess the clinical and electrocardiographic characteristics of patients diagnosed with ST elevation myocardial infarction (STEMI) that are associated with an increased likelihood of not undergoing percutaneous coronary intervention (PCI) after prehospital Cardiac Catheterization Laboratory activation in a regional STEMI system.

METHODS

We performed a retrospective analysis of prehospital Cardiac Catheterization Laboratory activations in Mecklenburg County, North Carolina, between May 2008 and March 2011. Data were extracted from the prehospital patient record, the prehospital electrocardiogram, and the regional STEMI database. The independent variables of interest included objective patient characteristics as well as documented cardiac history and risk factors. Analysis was performed using descriptive statistics and logistic regression.

RESULTS

Two hundred thirty-one prehospital activations were included in the analysis. Five independent variables were found to be associated with an increased likelihood of not undergoing PCI: increasing age, bundle branch block, elevated heart rate, left ventricular hypertrophy, and non-white race. The variables with the most significance were any type of bundle branch block [adjusted odds ratios (AOR), 5.66; 95% confidence interval (CI), 1.91-16.76], left ventricular hypertrophy (AOR, 4.63; 95% CI, 2.03-10.53), and non-white race (AOR, 3.53; 95% CI, 1.76-7.08). Conversely, the only variable associated with a higher likelihood of undergoing PCI was the presence of arm pain (AOR, 2.94; 95% CI, 1.36-6.25).

CONCLUSIONS

Several of the above variables are expected electrocardiogram mimics; however, the decreased rate of PCI in non-white patients highlights an area for investigation and process improvement. This may guide the development of prehospital STEMI protocols, although avoiding false positive and inappropriate activations.

Emergency medical services transport delays for suspected stroke and myocardial infarction patients

BACKGROUND

Prehospital delays in receiving emergency care for suspected stroke and myocardial infarction (MI) patients have significant impacts on health outcomes. Use of Emergency Medical Services (EMS) has been shown to reduce these delays. However, disparities in EMS transport delays are thought to exist. Therefore the objective of this study was to investigate and identify disparities in EMS transport times for suspected stroke and MI patients.

METHODS

Over 3,900 records of suspected stroke and MI patients, reported during 2006-2009, were obtained from two EMS agencies (EMS 1 & EMS 2) in Tennessee. Summary statistics of transport time intervals were computed. Multivariable logistic models were used to identify predictors of time intervals exceeding EMS guidelines.

RESULTS

Only 66 and 10 % of suspected stroke patients were taken to stroke centers by EMS 1 and 2, respectively. Most (80-83 %) emergency calls had response times within the recommended 10 min. However, over 1/3 of the calls had on-scene times exceeding the recommended 15 min. Predictors of time intervals exceeding EMS guidelines were EMS agency, patient age, season and whether or not patients were taken to a specialty center. The odds of total transport time exceeding EMS guidelines were significantly lower for patients not taken to specialty centers. Noteworthy was the 72 % lower odds of total time exceeding guidelines for stroke patients served by EMS 1 compared to those served by EMS 2. Additionally, for every decade increase in age of the patient, the odds of on-scene time exceeding guidelines increased by 15 and 19 % for stroke and MI patients, respectively.

CONCLUSION

In this study, prehospital delays, as measured by total transport time exceeding guideline was influenced by season, EMS agency responsible, patient age and whether or not the patient is transported to a specialty center. The magnitude of the delays associated with some of the factors are large enough to be clinically important although others, though statistically significant, may not be large enough to be clinically important. These findings should be useful for guiding future studies and local health initiatives that seek to reduce disparities in prehospital delays so as to improve health services and outcomes for stroke and MI patients.

Interfacility Transports Utilizing the 9-1-1 Emergency Medical Services System

BACKGROUND

With the increasing development of regional specialty centers, emergency physicians are often confronted with patients needing definitive care unavailable at their hospital. Interfacility transports (IFTs) may be a useful option to ensure timely, definitive patient care. However, since traditional IFT can be a challenging and time-consuming process, some EMS agencies that have previously limited their service to 9-1-1 emergency responses are now performing emergency IFTs.

OBJECTIVE

We sought to determine the frequency and nature of transfers provided by a local fire-based 9-1-1 EMS agency that recently began to provide limited IFT for time-critical emergencies.

METHODS

A retrospective review of paramedic reports for all IFTs between April 2007 and March 2014 in the City of Los Angeles, California. All IFTs initiated by 9-1-1 call from an emergency department (ED) and performed by Los Angeles Fire Department paramedics were included. Reason for transfer, patient demographics, and key time metrics were captured.

RESULTS

There were 919 IFTs during the study period, out of approximately 1,160,000 total ambulance transports (0.1%). The most frequent reason for IFT request was for transport of patients with ST segment elevation MI (STEMI) to a STEMI receiving center, followed by major trauma to a trauma center, and intracranial hemorrhage to a center with neurosurgical capability. Less common reasons included vascular emergencies, acute stroke, obstetric emergencies, and transfers to pediatric critical care facilities. Median transport time was 8 minutes (IQR 6-13 minutes) and median total time for IFT was 51 minutes (IQR 39-69 minutes). All IFTs involved a potentially life-threatening condition requiring a higher level of care than was available at the referring hospital.

CONCLUSIONS

Emergent ED-to-ED interfacility transport can provide access to time critical definitive care. EMS agencies that have limited the scope of their response to community 9-1-1 emergencies should have policies in place to assure timely response for emergent IFT requests.

An evaluation of emergency medical services stroke protocols and scene times

BACKGROUND

Acute stroke patients require immediate medical attention. Therefore, American Stroke Association guidelines recommend that for suspected stroke cases, emergency medical services (EMS) personnel spend less than 15 minutes on-scene at least 90% of the time. However, not all EMS providers include specific scene time limits in their stroke patient care protocols.

OBJECTIVE

We sought to determine whether having a protocol with a specific scene time limit was associated with less time EMS spent on scene. Methods. Stroke protocols from the 100 EMS systems in North Carolina were collected and abstracted for scene time instructions. Suspected stroke events occurring in 2009 were analyzed using data from the North Carolina Prehospital Medical Information System. Scene time was defined as the time from EMS arrival at the scene to departure with the patient. Quantile regression was used to estimate how the 90th percentile of the scene time distribution varied by systems with protocol instructions limiting scene time, adjusting for system patient volume and metropolitan status.

RESULTS

In 2009, 23 EMS systems in North Carolina had no instructions regarding scene time; 73 had general instructions to minimize scene time; and 4 had a specific limit for scene time (i.e., 10 or 15 min). Among 9,723 eligible suspected stroke events, mean scene time was 15.9 minutes (standard deviation 6.9 min) and median scene time was 15.0 minutes (90th percentile 24.3 min). In adjusted quantile regression models, the estimated reduction in the 90th percentile scene time, comparing protocols with a specific time limit to no instructions, was 2.2 minutes (95% confidence interval 1.3, 3.1 min). The difference in 90th percentile scene time between general and absent instructions was not statistically different (0.7 min [95% confidence interval -0.1, 1.4 min]).

CONCLUSION

Protocols with specific scene time limits were associated with EMS crews spending less time at the scene while general instructions were not. These findings suggest EMS systems can modestly improve scene times for stroke by specifying a time limit in their protocols.

Bypassing the Emergency Department and Time to Reperfusion in Patients With Prehospital ST-Segment–Elevation

Background—

Among patients identified prehospital with ST-segment–elevation myocardial infarction, emergency medical service transport from the field directly to the catheterization laboratory, thereby bypassing the emergency department (ED), may shorten time to reperfusion.

Methods and Results—

We studied 1687 patients identified prehospital with ST-segment–elevation myocardial infarction from the Reperfusion in Acute Myocardial Infarction in Carolina Emergency Departments (RACE) project, transported via emergency medical service directly to 21 North Carolina hospitals for primary percutaneous coronary intervention between July 2008 and December 2009. Treatment time intervals were compared between patients evaluated in the ED (ED evaluation) and those transported directly to the catheterization laboratory (ED bypass). Emergency medical service transported 1401 (83.0%) patients to the ED, whereas the ED was bypassed for 286 (17.0%) patients. Overall, first medical contact to device activation within 90 minutes was achieved in 913 (54.1%) patients. Among patients evaluated in the ED, median time (25th–75th percentiles) from ED arrival to catheterization laboratory arrival was 30 (20–41) minutes. First medical contact to device activation occurred faster (75 [59–93] versus 90 [76–109] minutes; P <0.001) and was more frequently achieved within 90 minutes (74.1% versus 50.1%; P <0.001) among ED bypass patients.

Conclusions—

Among patients identified prehospital with ST-segment–elevation myocardial infarction and transported directly to a percutaneous coronary intervention hospital, only 1 in 2 achieve device activation within 90 minutes. A median of 30 minutes is spent in the ED, contributing significantly to the failure to achieve timely reperfusion. The strategy to bypass the ED is used infrequently and represents a potential opportunity to improve reperfusion times.

Developing an ST-elevation myocardial infarction system of care in Dallas County

BACKGROUND

The American Heart Association Caruth Initiative (AHACI) is a multiyear project to increase the speed of coronary reperfusion and create an integrated system of care for patients with ST-elevation myocardial infarction (STEMI) in Dallas County, TX. The purpose of this study was to determine if the AHACI improved key performance metrics, that is, door-to-balloon (D2B) and symptom-onset-to-balloon times, for nontransfer patients with STEMI.

METHODS

Hospital patient data were obtained through the National Cardiovascular Data Registry Action Registry-Get With The Guidelines, and prehospital data came from emergency medical services (EMS) agencies through their electronic Patient Care Record systems. Initial D2B and symptom-onset-to-balloon times for nontransfer primary percutaneous coronary intervention (PCI) STEMI care were explored using descriptive statistics, generalized linear models, and logistic regression.

RESULTS

Data were collected by 15 PCI-capable Dallas hospitals and 24 EMS agencies. In the first 18 months, there were 3,853 cases of myocardial infarction, of which 926 (24%) were nontransfer patients with STEMI undergoing primary PCI. D2B time decreased significantly (P < .001), from a median time of 74 to 64 minutes. Symptom-onset-to-balloon time decreased significantly (P < .001), from a median time of 195 to 162 minutes.

CONCLUSION

The AHACI has improved the system of STEMI care for one of the largest counties in the United States, and it demonstrates the benefits of integrating EMS and hospital data, implementing standardized training and protocols, and providing benchmarking data to hospitals and EMS agencies.

Prehospital system delay in ST-segment elevation myocardial infarction care: a novel linkage of emergency medicine services and in hospital registry data

BACKGROUND

Emergency medical services (EMS) are critical in the treatment of ST-segment elevation myocardial infarction (STEMI). Prehospital system delays are an important target for improving timely STEMI care, yet few limited data are available.

METHODS

Using a deterministic approach, we merged EMS data from the North Carolina Pre-hospital Medical Information System (PreMIS) with data from the Reperfusion of Acute Myocardial Infarction in Carolina Emergency Departments-Emergency Response (RACE-ER) Project. Our sample included all patients with STEMI from June 2008 to October 2010 who arrived by EMS and who had primary percutaneous coronary intervention (PCI). Prehospital system delays were compared using both RACE-ER and PreMIS to examine agreement between the 2 data sources.

RESULTS

Overall, 8,680 patients with STEMI in RACE-ER arrived at a PCI hospital by EMS; 21 RACE-ER hospitals and 178 corresponding EMS agencies across the state were represented. Of these, 6,010 (69%) patients were successfully linked with PreMIS. Linked and notlinked patients were similar. Overall, 2,696 patients were treated with PCI only and were taken directly to a PCI-capable hospital by EMS; 1,750 were transferred from a non-PCI facility. For those being transported directly to a PCI center, 53% reached the 90-minute target guideline goal. For those transferred from a non-PCI facility, 24% reached the 120-minute target goal for primary PCI.

CONCLUSIONS

We successfully linked prehospital EMS data with in hospital clinical data. With this linked STEMI cohort, less than half of patients reach goals set by guidelines. Such a data source could be used for future research and quality improvement interventions.

Impact of the prehospital activation strategy in patients with ST-elevation myocardial infarction undergoing primary percutaneous revascularization: a single center community hospital experience

The strategy of prehospital activation by the emergency medical system (EMS) in patients with ST-elevation myocardial infarction (STEMI) has been poorly adopted among the US hospitals that currently offer 24/7 primary percutaneous coronary intervention. In this study, we report a single center experience after the implementation of this strategy. From 2008 to 2011, we identified a total 188 STEMI patients (age 65 ± 15 years) presenting via EMS for primary percutaneous coronary intervention. Of these, 112 (59.6%) underwent prehospital activation (EMS group), whereas the remaining 76 (40.4%) underwent emergency department activation [emergency department (ED) group]. Baseline demographic characteristics were similar between both groups. The overall median door-to-balloon (DTB) time was 49 ± 14 minutes. Patients undergoing prehospital activation had on average significantly lower overall DTB times (EMS 44 ± 11 minutes vs. ED 57 ± 15 minutes; P < 0.001). Concordantly, DTB times <60 minutes were much more commonly achieved with this strategy (EMS 95.5% vs. ED 64.5%; P < 0.001). Fallouts beyond the recommended 90-minute DTB time were seen among ED patients only. No difference in in-hospital death (EMS 5.4% vs. ED 6.6%; P = 0.75) or cumulative 30-day mortality (EMS 6.3% vs. ED 7.9%; P = 0.68) was observed between both groups. However, on average, EMS patients had higher postinfarct left ventricular ejection fraction (EMS 48 ± 9.5% vs. ED 39 ± 14.6%; P = 0.004). Differences in DTB time and left ventricular ejection fraction remained significant after adjusting for differences in baseline characteristics. In conclusion, the prehospital activation strategy is largely effective and should be systematically adopted in the treatment scheme of STEMI patients to lower mechanical reperfusion times and reduce the potential for untoward clinical outcomes.

De Facto regionalization of care for ST-elevation myocardial infarction in Florida, 2001-2009

ACC/AHA guidelines recommend STEMI patients receive percutaneous coronary intervention (PCI) at high volume hospitals performing ≥400 procedures/year. The objective of this study was to evaluate changes in the organization and implementation of care for STEMI patients in Florida. We assessed trends and predictors of STEMI patients first hospitalized at high PCI volume hospitals in Florida from 2001-2009. This is the first study to examine statewide trends in hospital admission for all STEMI patients. We classified Florida hospitals by PCI volume (high, medium, low, non-PCI) for each quarter from January, 2001 through June, 2009. Using hospital discharge data, we determined the percent of STEMI patients who went to each type of hospital and analyzed multiple predictors. From 2001-2009 the proportion of STEMI patients first hospitalized at high PCI volume hospitals rose from 62.4 to 89.7%, while admissions to non-PCI hospitals declined from 31% to 4.9%. Persistent barriers to high PCI volume hospital admission were age ≥85 years (OR 0.56, 95% CI 0.50-0.62), female gender (OR 0.85, 95% CI 0.79-0.91), and residence in a major metropolitan county. Through the efforts of local coalitions throughout Florida, by 2009 almost 90% of Florida STEMI patients were first admitted to high PCI volume hospitals. Greater hospital competition may explain lower admission rates to high PCI volume hospitals in major metropolitan counties. The age and gender disadvantage we observed requires further research to determine potential causes.

Understanding and benchmarking health service achievement of policy goals for chronic disease

BACKGROUND

Key challenges in benchmarking health service achievement of policy goals in areas such as chronic disease are: 1) developing indicators and understanding how policy goals might work as indicators of service performance; 2) developing methods for economically collecting and reporting stakeholder perceptions; 3) combining and sharing data about the performance of organizations; 4) interpreting outcome measures; 5) obtaining actionable benchmarking information. This study aimed to explore how a new Boolean-based small-N method from the social sciences-Qualitative Comparative Analysis or QCA-could contribute to meeting these internationally shared challenges.

METHODS

A 'multi-value QCA' (MVQCA) analysis was conducted of data from 24 senior staff at 17 randomly selected services for chronic disease, who provided perceptions of 1) whether government health services were improving their achievement of a set of statewide policy goals for chronic disease and 2) the efficacy of state health office actions in influencing this improvement. The analysis produced summaries of configurations of perceived service improvements.

RESULTS

Most respondents observed improvements in most areas but uniformly good improvements across services were not perceived as happening (regardless of whether respondents identified a state health office contribution to that improvement). The sentinel policy goal of using evidence to develop service practice was not achieved at all in four services and appears to be reliant on other kinds of service improvements happening.

CONCLUSIONS

The QCA method suggested theoretically plausible findings and an approach that with further development could help meet the five benchmarking challenges. In particular, it suggests that achievement of one policy goal may be reliant on achievement of another goal in complex ways that the literature has not yet fully accommodated but which could help prioritize policy goals. The weaknesses of QCA can be found wherever traditional big-N statistical methods are needed and possible, and in its more complex and therefore difficult to empirically validate findings. It should be considered a potentially valuable adjunct method for benchmarking complex health policy goals such as those for chronic disease.

[Primary PCI in ST-elevation myocardial infarction: mode of referral and time to PCI]

INTRODUCTION

According to the current guidelines for treatment of ST-elevation myocardial infarction (STEMI), percutaneous coronary intervention (PCI) should be performed within 90 min of first medical contact and total ischemic time should not exceed 120 min. The aim of this study was to analyze compliance with STEMI guidelines in a tertiary PCI center.

METHODS

This was a prospective single-center registry of 223 consecutive STEMI patients referred for primary PCI between 2003 and 2007.

RESULTS

In this population (mean age 60±12 years, 76% male), median total ischemic time was 4h 30 min (<120 min in 4% of patients). The interval with the best performance was first medical contact to first ECG (median 8 min, <10 min in 59% of patients). The worst intervals were symptom onset to first medical contact (median 104 min, <30 min in 6%) and first ECG to PCI (median 140 min, <90 min in 16%). Shorter total ischemic time was associated with better post-PCI TIMI flow, TIMI frame count and ST-segment resolution (p<0.03). The three most common patient origins were two nearby hospitals (A and B) and the pre-hospital emergency system. The pre-hospital group had shorter total ischemic time than patients from hospitals A or B (2h 45 min vs. 4h 44 min and 6h 40 min, respectively, p<0.05), with shorter door-to-balloon time (89 min vs. 147 min and 146 min, respectively, p<0.05).

CONCLUSIONS

In this population, only a small proportion of patients with acute myocardial infarction underwent primary PCI within the recommended time. Patients referred through the pre-hospital emergency system, although a minority, had the best results in terms of early treatment. Compliance with the guidelines translates into better myocardial perfusion achieved through primary PCI.

2010: the emergency medical services literature in review

Emergency physicians, specialists, and primary care doctors across the health care delivery spectrum remain actively engaged in the provision of medical oversight for emergency medical services (EMS) systems, a vital link in the medical continuum of care. Practicing emergency physicians, regardless of their level of formal EMS training, interface with EMS system components and providers on a regular basis. It is important to remain aware of trends and practice patterns that have the potential to affect the care of emergency patients. PubMed was used to find articles for this review. The authors included EMS articles from 2010 felt applicable to all emergency physicians that fit the general topics discussed in this review. Some key articles from 2009 were also included. Case series were generally excluded. The selection is by no means an attempt to single out the best research articles. Like a single 12-lead electrocardiographic (ECG) tracing, this review represents a “snapshot” of current discussions in the EMS community. Prehospital medicine is a dynamic discipline, and its practice patterns are not identical to those found in a hospital emergency department (ED). The purpose of this literature review is to familiarize emergency physicians with some of the ongoing discussions in the prehospital literature.

EMS medical direction and prehospital practices for acute cardiovascular events

OBJECTIVE

The purpose of this analysis was to determine whether there is an association between type of emergency medical services (EMS) medical direction and local EMS agency practices and characteristics specifically related to emergency response for acute cardiovascular events.

METHODS

We surveyed 1,292 EMS agencies in nine states. For each cardiovascular prehospital procedure or practice, we compared the proportion of agencies that employed paid (full- or part-time) medical directors with the proportion of agencies that employed volunteer medical directors. We also compared the proportion of EMS agencies who reported direct interaction between emergency medical technicians (EMTs) and their medical director within the previous four weeks with the proportion of agencies who reported no direct interaction. Chi-square tests were used to assess statistical differences in proportion of agencies with a specific procedure by medical director employment status and medical director interaction. We repeated these comparisons using t-tests to evaluate mean differences in call volume.

RESULTS

The EMS agencies with prehospital cardiovascular response policies were more likely to report employment of a paid medical director and less likely to report employment of a volunteer medical director. Similarly, agencies with prehospital cardiovascular response practices were more likely to report recent medical director interaction and less likely to report absence of recent medical director interaction. Mean call volumes for chest pain, cardiac arrest, and stroke were higher among agencies having paid medical directors (compared with agencies having volunteer medical directors) and agencies having recent medical director interaction (compared with agencies not having recent medical director interaction).

CONCLUSIONS

Our study demonstrated that EMS agencies with a paid medical director and agencies with medical director interaction with EMTs in the previous four weeks were more likely to have prehospital cardiovascular procedures in place. Given the strong relationship that both employment status and direct interaction have with the presence of these practices, agencies with limited resources to provide a paid medical director or a medical director that can be actively involved with EMTs should be supported through partnerships and other interventions to ensure that they receive the necessary levels of medical director oversight.

The Critical Imperative: Prehospital Management of the Patient with ST-Elevation Myocardial Infarction

Prehospital care is critical to achieve the goal of timely reperfusion in patients with ST-elevation myocardial infarction. Prehospital care is delivered by emergency medical services (EMS) personnel, which include emergency medical dispatchers, first responders, and ambulance response. There is considerable variation in the training and capabilities of the EMS providers in the United States depending on the location (ie, rural vs urban) and local jurisdictions. In this article, the key components of prehospital care of the patient with ST-elevation myocardial infarction and the various levels of training and capabilities of EMS providers are discussed.

Prehospital diagnosis and triage of ST-elevation myocardial infarction by paramedics without advanced care training

BACKGROUND

Prehospital triage of ST-elevation myocardial infarction (STEMI) for primary percutaneous coronary intervention (PCI) reduces treatment times. Prehospital triage and transport of STEMI patients have traditionally been undertaken in emergency medical service systems with Advanced Care Paramedics (ACPs). However, ACPs are not available in many regions. A pilot study was conducted to determine the feasibility of prehospital STEMI triage in a region with only Primary Care Paramedics.

METHODS

Hemodynamically stable patients with chest pain and suspected STEMI were brought directly to a catheterization laboratory for primary PCI. End points included accuracy of prehospital STEMI identification, complications during transfer, and treatment times.

RESULTS

One hundred thirty-four consecutive patients with suspected STEMI were triaged for primary PCI. Only 1 patient developed complications during transport (rapid atrial flutter) that required ACP skills. One hundred thirty-three patients underwent urgent angiography, and 105 patients underwent PCI. Based on physician interpretation of the prehospital electrocardiogram, there was agreement with triage decision for 121 (90%) of the 134 cases. The final diagnosis based on the angiogram and cardiac markers was true STEMI for 106 patients and false positive for 28 patients. The median first medical contact to balloon time was 91 (81-115) minutes.

CONCLUSIONS

Hemodynamically stable patients with suspected STEMI can be safely and effectively transported directly for primary PCI by paramedics without advanced care training. Prehospital STEMI triage for primary PCI can be extended to regions that have few or no paramedics with advanced care training.

Rates of Cardiac Catheterization Cancelation for ST-Segment Elevation Myocardial Infarction After Activation by Emergency Medical Services or Emergency Physicians

Background—

For patients with an acute ST-segment elevation myocardial infarction, cardiac catheterization laboratory (CCL) activation by emergency medical technicians or emergency physicians has been shown to substantially reduce treatment times. One drawback to this approach involves overtriage, whereby CCL staffs are activated for patients who ultimately do not require emergent coronary angiography or for patients who undergo angiography but are not found to have coronary artery occlusion.

Methods and Results—

We examined CCL activation at 14 primary angioplasty hospitals to determine the course of management, including the rate of inappropriate activation. Among 3973 activations (29% by emergency medical technicians, 71% by emergency physicians) between December 2008 and December 2009, appropriate CCL activations occurred for 3377 patients (85%), with 2598 patients (76.9% of appropriate activations) receiving primary percutaneous coronary intervention. Reasons for inappropriate activations (596 patients; 15%) included ECG reinterpretations (427 patients; 72%) or the fact that the patient was not a CCL candidate (169 patients; 28%). The rate of cancellation because of reinterpretation of emergency medical technicians' ECG (6% of all activations) was more common than for cancellation because of reinterpretation of emergency physicians' ECG (4.6%).

Conclusions—

This represents the first report of the rates of CCL cancellation for ST-segment elevation myocardial infarction system activation by emergency medical technicians and emergency physicians in a large group of hospitals organized within a statewide program. The high rate of coronary intervention and relatively low rate of inappropriate activation suggest that systematic CCL activation by emergency personnel on a broad scale is feasible and accurate, and these rates set a benchmark for ST-segment elevation myocardial infarction systems.

Most Important Papers in ST-Elevation Myocardial Infarction

The following are highlights from the series, Circulation: Cardiovascular Interventions Topic Review. This series summarizes the most important manuscripts, as selected by the editors, that have published in the Circulation portfolio. The studies included in this article represent the most noteworthy research in the area of ST-elevation myocardial infarction. ( Circ Cardiovasc Interv. 2011;4:e55–e66.)

Hospital process intervals, not EMS time intervals, are the most important predictors of rapid reperfusion in EMS Patients with ST-segment elevation myocardial infarction

OBJECTIVE

To assess the relationship of emergency medical services (EMS) intervals and internal hospital intervals to the rapid reperfusion of patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

We performed a secondary analysis of a prospectively collected database of STEMI patients transported to a large academic community hospital between January 1, 2004, and December 31, 2009. EMS and hospital data intervals included EMS scene time, transport time, hospital arrival to myocardial infarction (MI) team activation (D2Page), page to catheterization laboratory arrival (P2Lab), and catheterization laboratory arrival to reperfusion (L2B). We used two outcomes: EMS scene arrival to reperfusion (S2B) ≤90 minutes and hospital arrival to reperfusion (D2B) ≤90 minutes. Means and proportions are reported. Pearson chi-square and multivariate regression were used for analysis.

RESULTS

During the study period, we included 313 EMS-transported STEMI patients with 298 (95.2%) MI team activations. Of these STEMI patients, 295 (94.2%) were taken to the cardiac catheterization laboratory and 244 (78.0%) underwent percutaneous coronary intervention (PCI). For the patients who underwent PCI, 127 (52.5%) had prehospital EMS activation, 202 (82.8%) had D2B ≤90 minutes, and 72 (39%) had S2B ≤90 minutes. In a multivariate analysis, hospital processes EMS activation (OR 7.1, 95% CI 2.7, 18.4], Page to Lab [6.7, 95% CI 2.3, 19.2] and Lab arrival to Reperfusion [18.5, 95% CI 6.1, 55.6]) were the most important predictors of Scene to Balloon ≤ 90 minutes. EMS scene and transport intervals also had a modest association with rapid reperfusion (OR 0.85, 95% CI 0.78, 0.93 and OR 0.89, 95% CI 0.83, 0.95, respectively). In a secondary analysis, Hospital processes (Door to Page [OR 44.8, 95% CI 8.6, 234.4], Page 2 Lab [OR 5.4, 95% CI 1.9, 15.3], and Lab arrival to Reperfusion [OR 14.6 95% CI 2.5, 84.3]), but not EMS scene and transport intervals were the most important predictors D2B ≤90 minutes.

CONCLUSIONS

In our study, hospital process intervals (EMS activation, door to page, page to laboratory, and laboratory to reperfusion) are key covariates of rapid reperfusion for EMS STEMI patients and should be used when assessing STEMI care.

Paramedic contact to balloon in less than 90 minutes: a successful strategy for st-segment elevation myocardial infarction bypass to primary percutaneous coronary intervention in a canadian emergency medical system

INTRODUCTION

Few systems worldwide have achieved the benchmark time of less than 90 minutes from emergency medical services (EMS) contact to balloon inflation (E2B) for patients sustaining ST-segment elevation myocardial infarction (STEMI). We describe a successful EMS systems approach using a combination of paramedic and 12-lead electrocardiogram (ECG) software interpretation to activate a STEMI bypass protocol.

OBJECTIVES

To determine the proportion of patients who met the benchmark of E2B in less than 90 minutes after institution of a regional paramedic activated STEMI bypass to primary PCI protocol.

METHODS

We conducted a before-and-after observational cohort study over a 24-month period ending December 31, 2009. Included were all patients diagnosed with STEMI by paramedics trained in ECG acquisition and interpretation and transported by EMS. In the "before" phase of the study, paramedics gave emergency departments (EDs) advance notification of the arrival of STEMI patients and took the patients to the ED of the PCI center. In the "after" phase of the study, paramedics activated a STEMI bypass protocol in which STEMI patients were transported directly to the PCI suite, bypassing the local hospital EDs. Transmission of ECGs did not occur in either phase of the study.

RESULTS

We compared the times for 95 STEMI patients in the before phase with the times for 80 STEMI patients in the after phase. The proportion for whom E2B was less than 90 minutes increased from 28.4% before to 91.3% after (p < 0.001). Median E2B time decreased from 107 minutes (interquartile range [IQR] = 30) before to 70 minutes (IQR = 24) after. Median D2B time decreased from 83 minutes (IQR = 34) before to 35 minutes (IQR = 19) after. Median E2D time increased from 21 minutes (IQR = 8) before to 32 minutes (IQR = 17) after. Median differences between phases were significant at p < 0.001. The rate of false-positive PCI laboratory activation during the after phase of the study was 12.4%.

CONCLUSIONS

The proportion of patients with E2B times less than 90 minutes significantly improved through the implementation of a paramedic-activated STEMI bypass protocol. Further study is required to determine whether these benefits are reproducible in other EMS systems.