The prehospital electrocardiogram in acute myocardial infarction: is its full potential being realized? National Registry of Myocardial Infarction 2 Investigators

Usefulness of Prehospital 12-Lead Electrocardiography System in ST-Segment Elevation Myocardial Infarction Patients in Oita - Comparison Between Urban and Rural Areas, Weekday Daytime and Weekday Nighttime/Holidays

BACKGROUND

We have reported that a prehospital 12-lead electrocardiography system (P-ECG) contributed to transport of suspected acute coronary syndrome (ACS) patients to appropriate institutes and in this study, we compared its usefulness between urban and rural areas, and between weekday daytime and weekday nighttime/holiday.

METHODS AND RESULTS

Consecutive STEMI patients who underwent successful primary percutaneous coronary intervention after using P-ECG were assigned to the P-ECG group (n=123; 29 female, 70±13 years), and comparable STEMI patients without using P-ECG were assigned to the conventional group (n=117; 33 females, mean age 70±13 years). There was no significant difference in door-to-reperfusion times between the rural and urban cases (70±32 vs. 69±29 min, P=0.73). Door-to-reperfusion times in the urban P-ECG group were shorter than those in the urban conventional group for weekday nighttime/holiday (65±21 vs. 83±32 min, P=0.0005). However, there was no significance different between groups for weekday daytime. First medical contact to reperfusion time (90±22 vs. 105±37 min, P=0.0091) in the urban P-ECG group were significantly shorter than in the urban conventional groups for weekday nighttime/holiday, but were not significantly different between the groups for weekday daytime.

CONCLUSIONS

P-ECG is useful even in urban areas, especially for patients who develop STEMI during weekday nighttime or while on a holiday.

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

Objective

To 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.

Methods

The 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.

Results

Between 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.

Conclusion

Implementation 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.

Prehospital 12-Lead Electrocardiography System in Oita Assisted Transport of "True" Acute Coronary Syndrome Patients to Optimal Institutes

BACKGROUND

Mobile cloud electrocardiography (C-ECG) can reduce the door-to-balloon time of acute coronary syndrome (ACS) patients, so we hypothesized it would also assist in transporting ACS-suspected patients to the optimal institutes.

METHODS AND RESULTS

Initially, 10 fire departments in Oita had 10 ambulances equipped with C-ECG. Ambulance crews recorded a 12-lead ECG from the patient at the first point of contact and transmitted them to 18 hospitals (13 institutions (PCII) with 24-h availability for percutaneous coronary intervention (PCI) and 5 regional core hospitals (RCH) without 24-h PCI) for analysis by a cardiologist. During 41 months, 476 ECGs suspected to be ACS were transmitted and analyzed. Of these, 24 ECGs transmitted to PCII were judged as not requiring PCI, and the patients were directly transported to a RCH (PCII-RCH); 35 ECGs sent to a RCH were judged as requiring PCI, and the patients were directly transported to a PCII (RCH-PCII). The prevalence of cardiovascular disease was significantly higher in the RCH-PCII group than in the PCII-RCH group (P<0.01). There was no significant difference in the door-to-balloon time between the RCH-PCII and the group in which the C-ECG was sent to a PCII and the patients were transported directly to PCII (PCII-PCII) (49±14 vs. 59±20 min, P=0.14).

CONCLUSIONS

Prehospital 12-lead ECG can assist in transporting ACS-suspect patients to the optimal treatment facility.

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.

Clinical significance of prehospital 12-lead electrocardiography in patients with ST-segment elevation myocardial infarction presenting with syncope: from a multicenter observational registry (K-ACTIVE study)

Patients with acute myocardial infarction (AMI) presenting with syncope have poor clinical outcomes partly due to a delay in the diagnosis. Although the impact of prehospital 12-lead electrocardiography (PHECG) on the reduction of first medical contact (FMC)-to-device time and subsequent adverse clinical events in patients with AMI has been demonstrated, the impact of PHECG for the patients presenting with syncope remains to be elucidated. This study aimed to explore the impact of PHECG on 30-day mortality in patients with ST-segment elevation myocardial infarction (STEMI) presenting with syncope. From a cohort of multi-center registry [Kanagawa-ACuTe cardIoVascular rEgistry (K-ACTIVE)], a total of 90 consecutive patients with STEMI presenting with syncope were included. The 30-day mortality were compared between patients with PHECG (PHECG group, n = 25) and those without PHECG (non-PHECG group, n = 65). There was no significant difference in the baseline clinical characteristics between the 2 groups. FMC-to-device time was significantly shorter in the PHECG group than in the non-PHECG group (122 [86, 128] vs. 131 [102, 153] min, p = 0.03) due to the shorter door-to-device time. Thirty-day mortality was significantly lower in the PHECG group than in the non-PHECG group (16.0 vs. 44.6%, p = 0.03). In conclusion, PHECG was associated with shorter FMC-to-device time and lower 30-day mortality in patients with STEMI presenting with syncope.

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

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

ST-Segment Elevation Myocardial Infaction Alert During the Night Shift, A Misfortune for the Patient or an Overstatement?

Background

Conflicting data exist regarding the outcomes of primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) based on intervention timings. It is believed that short staffing at night hours may lead to a lapse in the delivery of effective, efficient and timely medical intervention.

Methods

A retrospective single-center study was performed, and a total of 436 patients were randomized into two groups. Group A had 279 patients who had the heart catheterization done during the daytime (between 6 am and 6 pm), while group B had 157 patients who had the same intervention performed at night (between 6 pm and 6 am).

Results

Door to balloon (DTB) time during the day was about 16 min shorter than the DTB time at night (81.29 ± 3.26 vs. 97.30 ± 8.54) with no statistical difference (P = 0.051). The mean troponin rise during the day was 1.94 ± 10.60 SEM (95% confidence interval (CI): -22.70 to 18.90) higher than night troponin levels (71.75 ± 7.18 vs. 69.80 ± 7.18), but P value was 0.85. The left ventricular ejection fraction (LVEF) fall for daytime was 0.93% vs. 0.90% for night time patients (P = 0.94).

Conclusion

There is no significant difference in the mean DTB time, the rise in troponin, fall in LVEF, readmission rates, or mortality, and hence no negative effects on patient outcomes based on the patient's time of presentation between the two groups.

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.

Achieving the earliest possible reperfusion in patients with acute coronary syndrome: a current overview

Acute coronary syndrome (ACS) remains one of the leading causes of mortality worldwide. Appropriate management of ACS will lead to a lower incidence of cardiac arrest. Percutaneous coronary intervention (PCI) is the first-line treatment for patients with ACS. PCI techniques have become established. Thus, the establishment of a system of health care in the prehospital and emergency department settings is needed to reduce mortality in patients with ACS. In this review, evidence on how to achieve earlier diagnosis, therapeutic intervention, and decision to reperfuse with a focus on the prehospital and emergency department settings is systematically summarized. The purpose of this review is to generate current, evidence-based consensus on scientific and treatment recommendations for health care providers who are the initial points of contact for patients with signs and symptoms suggestive of ACS.

Sex Differences in Timeliness of Reperfusion in Young Patients With ST-Segment-Elevation Myocardial Infarction by Initial Electrocardiographic Characteristics

BACKGROUND

Young women with ST-segment-elevation myocardial infarction experience reperfusion delays more frequently than men. Our aim was to determine the electrocardiographic correlates of delay in reperfusion in young patients with ST-segment-elevation myocardial infarction.

METHODS AND RESULTS

We examined sex differences in initial electrocardiographic characteristics among 1359 patients with ST-segment-elevation myocardial infarction in a prospective, observational, cohort study (2008-2012) of 3501 patients with acute myocardial infarction, 18 to 55 years of age, as part of the VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients) study at 103 US and 24 Spanish hospitals enrolling in a 2:1 ratio for women/men. We created a multivariable logistic regression model to assess the relationship between reperfusion delay (door-to-balloon time >90 or >120 minutes for transfer or door-to-needle time >30 minutes) and electrocardiographic characteristics, adjusting for sex, sociodemographic characteristics, and clinical characteristics at presentation. In our study (834 women and 525 men), women were more likely to exceed reperfusion time guidelines than men (42.4% versus 31.5%; P<0.01). In multivariable analyses, female sex persisted as an important factor in exceeding reperfusion guidelines after adjusting for electrocardiographic characteristics (odds ratio, 1.57; 95% CI, 1.15-2.15). Positive voltage criteria for left ventricular hypertrophy and absence of a prehospital ECG were positive predictors of reperfusion delay; and ST elevation in lateral leads was an inverse predictor of reperfusion delay.

CONCLUSIONS

Sex disparities in timeliness to reperfusion in young patients with ST-segment-elevation myocardial infarction persisted, despite adjusting for initial electrocardiographic characteristics. Left ventricular hypertrophy by voltage criteria and absence of prehospital ECG are strongly positively correlated and ST elevation in lateral leads is negatively correlated with reperfusion delay.

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

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

Impact of a rapid access protocol on decreasing door-to-balloon time in acute ST elevation myocardial infarction

Objective:

Ischemic cardiovascular disease is the leading cause of death in Canada. In ST elevation myocardial infarction (STEMI), time to reperfusion is a key determinant in reducing morbidity and mortality with percutaneous coronary intervention (PCI) being the preferred reperfusion strategy. Where PCI is available, delays to definitive care include times to electrocardiogram (ECG) diagnosis and cardiovascular laboratory access. In 2004, the Cardiac Care Network of Ontario recommended implementation of an emergency department (ED) protocol to reduce reperfusion time by transporting patients with STEMI directly to the nearest catheterization laboratory. The model was implemented in Frontenac County in April 2005. The objective of this study was to assess the effectiveness of a protocol for rapid access to PCI in reducing door-to-balloon times in STEMI.

Methods:

Two 1-year periods before and after implementation of a rapid access to PCI protocol (ending March 2005 and June 2006, respectively) were studied. Administrative databases were used to identify all subjects with STEMI who were transported by regional emergency medical services (EMS) and received emergent PCI. The primary outcome measure was time from ED arrival to first balloon inflation (door-to-balloon time). Times are presented as medians and interquartile ranges (IQRs). Statistical comparisons were made using the Mann–Whitney U test and presented graphically with Kaplan–Meier curves.

Results:

Patients transported under the rapid access protocol (n = 39) were compared with historical controls (n = 42). Median door-to-balloon time was reduced from 87 minutes (IQR 67–108) preprotocol to 62 minutes (IQR 40–80) postprotocol (p &lt; 0.001).

Conclusion:

In our region, implementation of an EMS protocol for rapid access to PCI significantly reduced time to reperfusion for patients with STEMI.

Emergency medical services as a strategy for improving ST-elevation myocardial infarction system treatment times

BACKGROUND

Reducing delays in time to treatment is a key goal of ST-elevation myocardial infarction (STEMI) emergency care. Emergency medical services (EMS) are a critical component of the STEMI chain of survival.

STUDY OBJECTIVE

We sought to assess the impact of the careful integration of EMS as a strategy for improving systemic treatment times for STEMI.

METHODS

We conducted a study of all 747 nontransfer STEMI patients who underwent primary percutaneous coronary intervention (PCI) in Dallas County, Texas from October 1, 2010 through December 31, 2011. EMS leaders from 24 agencies and 15 major PCI receiving hospitals collected and shared common, de-identified patient data. We used 15 months of data to develop a generalized linear regression to assess the impact of EMS on two treatment metrics-hospital door to balloon (D2B) time, and symptom onset to arterial reperfusion (SOAR) time, a new metric we developed to assess total treatment times.

RESULTS

We found statistically significant reductions in median D2B (11.1-min reduction) and SOAR (63.5-min reduction) treatment times when EMS transported patients to the receiving facility, compared to self-transport. In addition, when trained EMS paramedics field-activated the cardiac catheterization laboratory using predefined specified protocols, D2B times were reduced by 38% (43 min) after controlling for confounding variables, and field activation was associated with a 21.9% reduction (73 min) in the mean SOAR time (both with p < 0.001).

CONCLUSION

Active EMS engagement in STEMI treatment was associated with significantly lower D2B and total coronary reperfusion times.

The chain of survival for ST-segment elevation myocardial infarction: insights into the Middle East

Although coronary heart disease is the leading cause of morbidity and mortality in the Middle East (ME), not much is known about patients with ST-segment elevation myocardial infarction (STEMI) from this region. The STEMI Chain of Survival can be used to target regional improvements in patient care. We tried to adopt a modified chain of survival for STEMI to highlight the challenges and difficulties and the possible solutions to improve the STEMI care in the Middle East based on the few data available.

Risk prediction for myocardial infarction via generalized functional regression models

In this paper, we propose a generalized functional linear regression model for a binary outcome indicating the presence/absence of a cardiac disease with multivariate functional data among the relevant predictors. In particular, the motivating aim is the analysis of electrocardiographic traces of patients whose pre-hospital electrocardiogram (ECG) has been sent to 118 Dispatch Center of Milan (the Italian free-toll number for emergencies) by life support personnel of the basic rescue units. The statistical analysis starts with a preprocessing of ECGs treated as multivariate functional data. The signals are reconstructed from noisy observations. The biological variability is then removed by a nonlinear registration procedure based on landmarks. Thus, in order to perform a data-driven dimensional reduction, a multivariate functional principal component analysis is carried out on the variance-covariance matrix of the reconstructed and registered ECGs and their first derivatives. We use the scores of the Principal Components decomposition as covariates in a generalized linear model to predict the presence of the disease in a new patient. Hence, a new semi-automatic diagnostic procedure is proposed to estimate the risk of infarction (in the case of interest, the probability of being affected by Left Bundle Brunch Block). The performance of this classification method is evaluated and compared with other methods proposed in literature. Finally, the robustness of the procedure is checked via leave-j-out techniques.

Setting Up a Population-Based Program to Optimize ST-Segment Elevation Myocardial Infarction Care

The development of ST-segment elevation myocardial infarction (STEMI) systems of care at the city, region, or nation levels has not only improved the speed of reperfusion but also enhanced the reach of primary angioplasty to areas far from percutaneous coronary intervention (PCI) centers. Setting up a STEMI system of care is a sophisticated process that requires a solid PCI hospital and emergency medical services infrastructure, disciplined collaboration, and a focus on outcomes measurement and continuous quality improvement. This article reviews the accumulated evidence supporting the development of STEMI systems of care and offers practical insights into this process.

Pre-hospital electrocardiography by emergency medical personnel: effects on scene and transport times for chest pain and ST-segment elevation myocardial infarction patients

OBJECTIVES

This study sought to measure the impact of pre-hospital (PH) electrocardiography (ECG) on scene-to-hospital time for patients with chest pain of cardiac origin and those with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

Pre-hospital ECG decreases door-to balloon (D2B) time for STEMI patients. However, obtaining a PH ECG might prolong scene time. We investigated the impact of obtaining a PH ECG on both scene and transport times for patients with chest pain suspected of cardiac origin.

METHODS

City of San Diego Emergency Medical System runsheets of patients with chest pain from January 2003 to April 2008 were analyzed. The scene times and transport times were compared before (from January 2003 to December 2005) and after (from January 2006 to April 2008) implementation of the PH ECG. Among patients with a PH ECG, median scene times and transport times were compared in patients with and without STEMI.

RESULTS

There were 21,742 patients evaluated for chest pain during the study period. Implementation of PH ECG resulted in minimal increases in median scene time (19 min, 10 s vs. 19 min, 28 s, p = 0.002) and transport time (13 min, 16 s vs. 13 min, 28 s, p = 0.007). However, compared with chest pain patients, in STEMI patients (n = 303), shorter median scene time (17 min, 51 s vs. 19 min, 31 s, p < 0.001), transport time (12 min, 34 s vs. 13 min, 31 s, p = 0.006), and scene-to-hospital time was observed (30 min, 45 s vs. 33 min, 29 s, p < 0.001).

CONCLUSIONS

Obtaining a PH ECG for patients with chest pain minimally prolongs scene and transport times. Further, for STEMI patients, both scene times and transport times are actually reduced leading to a potential reduction in total ischemic time.

Ability of First-Year Paramedic Students to Identify ST-Segment Elevation Myocardial Injury on 12-Lead Electrocardiogram: A Pilot Study

Introduction:

The purpose of this study was to evaluate the ability of first-year paramedic students to identify ST-segment elevation myocardial injury (STEMI) on 12-lead electrocardiograms (ECGs) following a three-hour presentation by a board-certified emergency medicine physician experienced in ECG interpretation.

Methods:

Thirty-three first-year paramedic students with minimal to no experience in evaluating 12-lead ECGs were administered a pretest with 20 12-lead ECGs and were asked to evaluate each for: (1) presence of STEMI (STEMI identification); (2) if STEMI presents, ECG leads demonstrating ST-elevation (LEAD identification); and (3) if STEMI present, the anatomic distribution of the STEMI (ANATOMY identification). The students were randomized into two groups. Group 1 (16 students; control group) received a handout describing the evaluation of ECGs for STEMI, while Group 2 (17 students; experimental group) received the handout plus a threehour presentation on the evaluation of ECGs for STEMI. Following randomization, distribution of the STEMI handout and ECG STEMI presentation, a posttest with 20 new ECGs was administered to all participants. The pretest and posttest mean scores were compared between the two groups to determine if attendance at the presentation improved the paramedic students' abilities to evaluate and identify STEMI ECGs. Following the STEMI posttest, students in Group 1 were provided with the STEMI lecture. Students were retested with 20 new ECGs five months following the initial study to examine retention of the information taught.

Results:

The mean pre-test scores for the two groups (Group 1 vs Group 2, respectively) in STEMI identification (74.4 vs 75.6%; p = 0.79), lead identification (50.0 vs. 51.2%; p = 0.8) and anatomy identification (49.4 vs 51.8%; p = 0.60) were similar in all three categories. Post-test scores between Group 1 and Group 2 demonstrated statistically significant differences in STEMI identification (85.6 vs 92.4%; p <0.02), lead identification (73.4 vs 85.2%; p <0.02), and anatomy identification (65.9 vs 87.1%; p <0.01), with Group 2 demonstrating higher mean scores relative to Group 1 in all three categories. Comparison of mean initial pre-test and five-month retest scores for all students demonstrated statistically significant differences in STEMI identification (75.0 vs 87.4%; p <0.0001), lead identification (50.6 vs 82.2%; p <0.0001), and anatomy identification (50.6 vs 76.6%; p <0.0001).

Conclusions:

The ability of first-year paramedic students to accurately detect STEMI on prehospital 12-lead ECGs is enhanced by a structured ECG STEMI presentation provided by an emergency medicine physician, and these students maintained excellent retention of STEMI ECG skills over a five-month period.

Prehospital electrocardiography: a review of the literature

INTRODUCTION

The American Heart Association and other scientific guidelines recommend emergency medical services acquire prehospital (PH) electrocardiography (ECG) in all patients with symptoms of acute coronary syndrome. The purpose of this article is to critically review the scientific literature about PH ECG.

METHODS

Using multiple search terms, we searched the PubMed and Web of Science databases for relevant information. Search limiters were used: human, research (clinical trials, experimental), core journals, and adult. All articles about the clinical effects of PH ECG published between 2001 and 2011 were retained, in addition to a landmark study from 1997.

RESULTS

Our search yielded a total of 105 articles when all years of publication were considered. When the same search was limited to articles published between 2001 and 2011 for new and current data, 45 articles were returned. A total of 7 articles about the clinical effects of PH ECG were retained for this review. Articles were conceptualized and organized by clinical effects of PH ECG (timing, reperfusion rate, death, ejection fraction, reinfarction, and stroke). PH ECG has been associated with reduced PH delay time, increased use of reperfusion interventions, earlier diagnosis, and faster time to treatment.

DISCUSSION

PH ECG plays a major role in emergency cardiac systems of care and can facilitate early intervention by identifying patients with acute coronary syndrome sooner.

Pre-hospital ECG in patients undergoing primary percutaneous interventions within an integrated system of care: reperfusion times and long-term survival benefits

AIMS

Treatment delay is a powerful predictor of survival in STEMI patients undergoing primary PCI. We investigated the effectiveness of pre-hospital triage with direct referral to PCI, alongside more conventional referral strategies.

METHODS AND RESULTS

From January 2003 to December 2007, 1,619 STEMI patients were referred for primary PCI at our cathlab through two main triage groups: i.e., 1) following pre-hospital triage (n=524), 2) via more conventional triages (n=1,095) represented by the S. Orsola-Malpighi hospital emergency department triage (hub hospital) and local hospital triage. Pre-hospital diagnosis was associated with a 76 minute reduction in pain-to-balloon time (143 [107-216] vs. 219 [149-343], p=0.001) allowing mechanical revascularisation within 90 minutes from the first medical contact in the vast majority of the patients (>80%). Clinically, pre-hospital triage showed no significant reductions in terms of adjusted long-term mortality (HR 0.81, 95% CI 0.61-1.08; p=0.16) in the overall population. However, significant adjusted survival benefits were observed in high-risk groups (i.e., cardiogenic shock, TIMI risk score >30, diabetes mellitus).

CONCLUSIONS

This study shows that pre-hospital diagnosis allows for significant reductions in primary PCI treatment delays and suggests the hypothesis that this referral strategy might provide long-term survival benefits especially in high-risk patients.

A simple strategy improves prehospital electrocardiogram utilization and hospital treatment for patients with acute coronary syndrome (from the ST SMART Study)

Although the American Heart Association recommends a prehospital electrocardiogram (ECG) be recorded for all patients who access the emergency medical system with symptoms of acute coronary syndrome (ACS), widespread use of prehospital ECG has not been achieved in the United States. A 5-year prospective randomized clinical trial was conducted in a predominately rural county in northern California to test a simple strategy for acquiring and transmitting prehospital ECGs that involved minimal paramedic training and decision making. A 12-lead ECG was synthesized from 5 electrodes and continuous ST-segment monitoring was performed with ST-event ECGs automatically transmitted to the destination hospital emergency department. Patients randomized to the experimental group had their ECGs printed out in the emergency department with an audible voice alarm, whereas control patients had an ECG after hospital arrival, as was the standard of care in the county. The result was that nearly 3/4 (74%) of 4,219 patients with symptoms of ACS over the 4-year study enrollment period had a prehospital ECG. Mean time from 911 call to first ECG was 20 minutes in those with a prehospital ECG versus 79 minutes in those without a prehospital ECG (p <0.0001). Mean paramedic scene time in patients with a prehospital ECG was just 2 minutes longer than in those without a prehospital ECG (95% confidence interval 1.2 to 3.6, p <0.001). Patients with non-ST-elevation myocardial infarction or unstable angina pectoris had a faster time to first intravenous drug and there was a suggested trend for a faster door-to-balloon time and lower risk of mortality in patients with ST-elevation myocardial infarction. In conclusion, increased paramedic use of prehospital ECGs and decreased hospital treatment times for ACS are feasible with a simple approach tailored to characteristics of a local geographic region.

Six Sigma process utilization in reducing door-to-balloon time at a single academic tertiary care center

BACKGROUND

Rapid reperfusion in patients with ST-elevation myocardial infarction (STEMI) is associated with lower mortality. Reduction in door-to-balloon (D2B) time for percutaneous coronary intervention requires multidisciplinary cooperation, process analysis, and quality improvement methodology.

METHODS

Six Sigma methodology was used to reduce D2B times in STEMI patients presenting to a tertiary care center. Specific steps in STEMI care were determined, time goals were established, and processes were changed to reduce each step's duration. Outcomes were tracked, and timely feedback was given to providers.

RESULTS

After process analysis and implementation of improvements, mean D2B times decreased from 128 to 90 minutes. Improvement has been sustained; as of June 2010, the mean D2B was 56 minutes, with 100% of patients meeting the 90-minute window for the year.

CONCLUSION

Six Sigma methodology and immediate provider feedback result in significant reductions in D2B times. The lessons learned may be extrapolated to other primary percutaneous coronary intervention centers.

[Can we improve the management of acute coronary syndromes in primary care?]

OBJECTIVE

To evaluate a training programme in the primary care of acute coronary syndrome.

DESIGN

A before-during-after comparative cross-sectional study.

SETTING

Health areas of Lleida, High Pyrenees and Aran (Spain), from 2003-2006.

PARTICIPANTS

Patients with acute coronary syndrome admitted to the intensive medicine unit and the coronary unit of the Arnau de Vilanova University Hospital of Lleida after being referred from home, general practitioner or health centre.

INTERVENTION

A training program was introduced to establish protocols of pre-hospital performance in acute coronary syndrome (the administration of acetylsalicylic acid, nitroglycerin and morphine chloride, the performing of an electrocardiogram, the insertion of an intravenous tube and to speed up care times).

MAIN MEASURES

Linear trend of the three periods of the study was analyzed through prevalences ratio and linear trend test.

RESULTS

The intervention showed a statistically significant linear increase in the application of the aforementioned therapeutic procedures, with the exception of nitroglycerin, which started out with a higher baseline level, and an improvement of care times. The application of an electrocardiogram obtained almost optimal levels. Care times considerably improved.

CONCLUSIONS

Training programs are a useful tool in improving treatment of acute coronary syndromes in primary care. Advance diagnosis and an early start to treatment almost certainly results in a decrease of its morbidity-mortality.

Management of Acute ST-Elevation Myocardial Infarction: Reperfusion Options

Primary percutaneous coronary intervention and thrombolysis remain therapies of choice for patients presenting with ST-segment elevation myocardial infarction (STEMI). Clinical outcome in the management of acute STEMI is dependent on myocardial reperfusion time and reperfusion strategies. Optimisation of these strategies should take into consideration logistical limitations of the local medical systems and the various patient profiles. We review the reperfusion strategies and its history in Singapore, comparing its clinical application with that in some developed Western countries. Key words: Acute Myocardial Infarction, Primary Percutaneous Coronary Intervention, ST segment Elevation Myocardial Infarction, Thrombolysis