Prehospital 12-Lead ECG to Triage ST-Elevation Myocardial Infarction and Emergency Department Activation of the Infarct Team Significantly Improves Door-to-Balloon Times

A Novel Algorithm for Improving the Prehospital Diagnostic Accuracy of ST-Segment Elevation Myocardial Infarction

INTRODUCTION

Early detection of ST-segment elevation myocardial infarction (STEMI) on the prehospital electrocardiogram (ECG) improves patient outcomes. Current software algorithms optimize sensitivity but have a high false-positive rate. The authors propose an algorithm to improve the specificity of STEMI diagnosis in the prehospital setting.

METHODS

A dataset of prehospital ECGs with verified outcomes was used to validate an algorithm to identify true and false-positive software interpretations of STEMI. Four criteria implicated in prior research to differentiate STEMI true positives were applied: heart rate <130, QRS <100, verification of ST-segment elevation, and absence of artifact. The test characteristics were calculated and regression analysis was used to examine the association between the number of criteria included and test characteristics.

RESULTS

There were 44,611 cases available. Of these, 1,193 were identified as STEMI by the software interpretation. Applying all four criteria had the highest positive likelihood ratio of 353 (95% CI, 201-595) and specificity of 99.96% (95% CI, 99.93-99.98), but the lowest sensitivity (14%; 95% CI, 11-17) and worst negative likelihood ratio (0.86; 95% CI, 0.84-0.89). There was a strong correlation between increased positive likelihood ratio (r2 = 0.90) and specificity (r2 = 0.85) with increasing number of criteria.

CONCLUSIONS

Prehospital ECGs with a high probability of true STEMI can be accurately identified using these four criteria: heart rate <130, QRS <100, verification of ST-segment elevation, and absence of artifact. Applying these criteria to prehospital ECGs with software interpretations of STEMI could decrease false-positive field activations, while also reducing the need to rely on transmission for physician over-read. This can have significant clinical and quality implications for Emergency Medical Services (EMS) systems.

Electrocardiographic interpretation by emergency medical services professionals in Saudi Arabia: A cross sectional study

BACKGROUND

Management of acute myocardial infarction (AMI) and cardiac arrhythmias in prehospital settings is largely determined by providers of emergency medical services (EMS) who can proficiently interpret the electrocardiography (ECG). The aim of this study was to assess the ECG competency of EMS providers in Saudi Arabia.

METHODS

Between Aug and Sep 2022, we invited all EMS providers working for the Saudi Red Crescent Authority in Makkah, Riyadh, and Sharqiyah regions to complete a cross-sectional survey. The survey was used to assess the ability of EMS providers to interpret 12 ECG strips. Characteristics and ECG competency were summarized using descriptive statistics. Differences in ECG competency across paramedics with lower and higher qualifications were assessed.

RESULTS

During the study period, 231 participants completed the survey, and all were included. The overall mean age was 33.4, and most participants were male (94.8%). Nearly half of the participants were paramedics with an associate degree and 46.4% were paramedics with higher degrees. The average rate of correct answers to the 12 ECG strips was 43.3% (95% CI: 35.4%, 51.3%). Atrial flutter, ventricular fibrillation, atrial fibrillation, 3rd degree heart block, and ventricular tachycardia were identified by 52.8%, 60.2%, 42.0%, 40.7%, and 49.4% of the participants, respectively. The strip with an AMI was identified by 41.1%, while a pathological Q wave and ventricular extrasystole were identified by 19.1% and 24.7%, respectively. Paramedics with higher qualifications were as 28.0%-61.0% more likely to correctly interpret the 12 ECG strips compared to those with an associate degree (p-value across all variables was ≤ 0.001).

CONCLUSION

While the majority of participants in our region were unable to correctly answer the 12 ECG questionnaire, paramedics with higher qualifications were. Our study indicates that there is a need for evidenced-based ECG curricula targeting different levels of EMS professionals.

Prehospital Activation of the Cardiac Catheterization Laboratory in ST-Segment-Elevation Myocardial Infarction for Primary Percutaneous Coronary Intervention

Background Prehospital activation of the cardiac catheter laboratory is associated with significant improvements in ST-segment-elevation myocardial infarction (STEMI) performance measures. However, there are equivocal data, particularly within Australia, regarding its influence on mortality. We assessed the association of prehospital activation on performance measures and mortality in patients with STEMI treated with primary percutaneous coronary intervention from the Queensland Cardiac Outcomes Registry (QCOR). Methods and Results Consecutive ambulance-transported patients with STEMI treated with primary percutaneous coronary intervention were analyzed from January 1, 2017 to December 31, 2020 from the QCOR. The total and direct effects of prehospital activation on the primary outcomes (30-day and 1-year cardiovascular mortality) were estimated using logistic regression analyses. Secondary outcomes were STEMI performance measures. Among 2498 patients (mean age: 62.2±12.4 years; 79.2% male), 73% underwent prehospital activation. Median door-to-balloon time (34 minutes [26-46] versus 86 minutes [68-113]; P<0.001), first-electrocardiograph-to-balloon time (83.5 minutes [72-98] versus 109 minutes [81-139]; P<0.001), and proportion of patients meeting STEMI targets (door-to-balloon <60 minutes 90% versus 16%; P<0.001), electrocardiograph-to-balloon time <90 minutes (62% versus 33%; P<0.001) were significantly improved with prehospital activation. Prehospital activation was associated with significantly lower 30-day (1.6% versus 6.6%; P<0.001) and 1-year cardiovascular mortality (2.9% versus 9.5%; P<0.001). After adjustment, no prehospital activation was strongly associated with increased 30-day (odds ratio [OR], 3.6 [95% CI, 2.2-6.0], P<0.001) and 1-year cardiovascular mortality (OR, 3.0 [95% CI, 2.0-4.6]; P<0.001). Conclusions Prehospital activation of cardiac catheterization laboratory for primary percutaneous coronary intervention was associated with significantly shorter time to reperfusion, achievement of STEMI performance measures, and lower 30-day and 1-year cardiovascular mortality.

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

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

Internet of Things-Based ECG and Vitals Healthcare Monitoring System

Health monitoring and its associated technologies have gained enormous importance over the past few years. The electrocardiogram (ECG) has long been a popular tool for assessing and diagnosing cardiovascular diseases (CVDs). Since the literature on ECG monitoring devices is growing at an exponential rate, it is becoming difficult for researchers and healthcare professionals to select, compare, and assess the systems that meet their demands while also meeting the monitoring standards. This emphasizes the necessity for a reliable reference to guide the design, categorization, and analysis of ECG monitoring systems, which will benefit both academics and practitioners. We present a complete ECG monitoring system in this work, describing the design stages and implementation of an end-to-end solution for capturing and displaying the patient's heart signals, heart rate, blood oxygen levels, and body temperature. The data will be presented on an OLED display, a developed Android application as well as in MATLAB via serial communication. The Internet of Things (IoT) approaches have a clear advantage in tackling the problem of heart disease patient care as they can transform the service mode into a widespread one and alert the healthcare services based on the patient's physical condition. Keeping this in mind, there is also the addition of a web server for monitoring the patient's status via WiFi. The prototype, which is compliant with the electrical safety regulations and medical equipment design, was further benchmarked against a commercially available off-the-shelf device, and showed an excellent accuracy of 99.56%.

Clinical Outcomes in Pre-Hospital Activation and Direct Cardiac Catheterisation Laboratory Transfer of STEMI for Primary PCI

INTRODUCTION

Pre-hospital activation and direct cardiac catheterisation laboratory (CCL) transfer of ST segment elevation myocardial infarction (STEMI) has previously been shown to improve door-to-balloon (DTB) times yet there is limited outcome data in the Australian context. We aimed to assess the impact of pre-hospital activation on STEMI performance measures and mortality.

METHODS

Prospective cohort study of consecutive ambulance transported STEMI patients treated with primary percutaneous coronary intervention (PCI) patients over a 10-year period (1 January 2008-31 December 2017) at The Prince Charles Hospital, a large quaternary referral centre in Brisbane, Queensland Australia. Comparisons were performed between patients who underwent pre-hospital CCL activation and patients who did not. STEMI performance measures, 30-day and 1-year mortality were examined.

RESULTS

Amongst 1,009 patients included (mean age: 62.8 yrs±12.6), pre-hospital activation increased over time (26.6% in 2008 to 75.0% in 2017, p<0.001). Median DTB time (35 mins vs 76 mins p<0.001) and percentage meeting targets (DTB<60 mins 92% vs 27%, p<0.001) improved significantly with pre-hospital activation. Pre-hospital activation was associated with significantly lower 30-day (1.0% vs 3.5%, p=0.007) and 1-year (1.2% vs 7.7%, p<0.001) mortality. After adjusting for confounders and mediators, we observed a strong total effect of pre-hospital activation on 1-year mortality (OR 5.3, 95%CI 2.2-12.4, p<0.001) compared to patients who did not have pre-hospital activation. False positive rates were 3.7% with pre-hospital activation.

CONCLUSION

In patients who underwent primary PCI for STEMI, pre-hospital activation and direct CCL transfer is associated with low false positive rates, significantly reduced time to reperfusion and lower 30-day and 1-year mortality.

Incidence and Outcomes of Nontraumatic Shock in Adults Using Emergency Medical Services in Victoria, Australia

IMPORTANCE

Nontraumatic shock is a challenging clinical condition, presenting urgent and unique demands in the prehospital setting. There is a paucity of data assessing its incidence, etiology, and clinical outcomes.

OBJECTIVE

To assess the incidence, etiology, and clinical outcomes of patients treated by emergency medical services (EMS) with nontraumatic shock using a large population-based sample.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included consecutive adult patients with shock not related to trauma who received care by EMS between January 1, 2015, and June 30, 2019, in Victoria, Australia. Data were obtained from individually linked ambulance, hospital, and state death index data sets. During the study period there were 2 485 311 cases attended by EMS, of which 16 827 met the study's inclusion criteria for shock.

MAIN OUTCOMES AND MEASURES

The primary outcome was 30-day mortality. Secondary outcomes included length of hospital stay, emergency department discharge disposition, rates of coronary angiography and revascularization procedures, and the use of mechanical circulatory support.

RESULTS

A total of 12 695 patients were successfully linked, with a mean (SD) age of 65.7 (19.1) years; 6411 (50.5%) were men. The overall population-wide incidence of EMS-treated prehospital shock was 76 (95% CI, 75-77) per 100 000 person-years. An increased incidence was observed in men (79 [77-81] per 100 000 person-years), older patients (eg, aged 70-79 years: 177 [171-183] per 100 000 person-years), regional locations (outer regional or remote: 100 [94-107] per 100 000 person-years), and in areas with increased socioeconomic disadvantage (lowest socioeconomic status quintile: 92 [89-95] per 100 000 person-years). Patients with hospital outcome data were stratified into shock etiologies; 3615 (28.5%) had cardiogenic shock: 3998 (31.5%), septic shock; 1457 (11.5%), hypovolemic shock; and 3625 (28.6%), other causes of shock. Nearly one-third of patients (4158 [32.8%]) were deceased at 30 days. In multivariable analyses, increased age (all etiologies: hazard ratio [HR], 1.04; 95% CI, 1.03-1.04), female sex (cardiogenic shock: HR, 1.26; 95% CI, 1.12-1.42), increased initial heart rate (all etiologies: 1.01; 95% CI, 1.00-1.01), prehospital intubation (all etiologies: HR, 3.93; 95% CI, 3.48-4.44), and preexisting comorbidities (eg, chronic kidney disease, all etiologies: HR, 1.25; 95% CI, 1.10-1.42) were independently associated with 30-day mortality, while higher socioeconomic status (all etiologies: HR, 0.96; 95% CI, 0.94-0.98) and increased initial systolic blood pressure (all etiologies: HR, 0.99; 95% CI, 0.99-0.99) were associated with lower risk.

CONCLUSIONS AND RELEVANCE

This population-level cohort study found that EMS-treated nontraumatic shock was a common condition, with a high risk of morbidity and mortality regardless of etiology. It disproportionately affected men, older patients, patients in regional areas, and those with social disadvantage. Further studies are required to assess how current systems of care can be optimized to improve outcomes.

Can a Healthcare Quality Improvement Initiative Reduce Disparity in the Treatment Delay among ST-Segment Elevation Myocardial Infarction Patients with Different Arrival Modes? Evidence from 33 General Hospitals and Their Anticipated Impact on Healthcare during Disasters and Public Health Emergencies

(1) Background: Chest pain center accreditation has been associated with improved timelines of primary percutaneous coronary intervention (PCI) for ST-segment elevated myocardial infarction (STEMI). However, evidence from low- and middle-income regions was insufficient, and whether the sensitivity to improvements differs between walk-in and emergency medical service (EMS)-transported patients remained unclear. In this study, we aimed to examine the association of chest pain center accreditation status with door-to-balloon (D2B) time and the potential modification effect of arrival mode. (2) Methods: The associations were examined using generalized linear mixed models, and the effect modification of arrival mode was examined by incorporating an interaction term in the models. (3) Results: In 4186 STEMI patients, during and after accreditation were respectively associated with 65% (95% CI: 54%, 73%) and 71% (95% CI: 61%, 79%) reduced risk of D2B time being more than 90 min (using before accreditation as the reference). Decreases of 27.88 (95% CI: 19.57, 36.22) minutes and 26.55 (95% CI: 17.45, 35.70) minutes in D2B were also observed for the during and after accreditation groups, respectively. The impact of accreditation on timeline improvement was greater for EMS-transported patients than for walk-in patients. (4) Conclusions: EMS-transported patients were more sensitive to the shortened in-hospital delay associated with the initiative, which could exacerbate the existing disparity among patients with different arrival modes.

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.

Sex Differences in Prehospital Delays in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention

Background

Women with ST‐segment–elevation myocardial infarction experience delays in reperfusion compared with men with little data on each time component from symptom onset to reperfusion. This study analyzed sex discrepancies in patient delays, prehospital system delays, and hospital delays.

Methods and Results

Consecutive patients with ST‐segment–elevation myocardial infarction treated with percutaneous coronary intervention across 30 hospitals in the Victorian Cardiac Outcomes Registry (2013–2018) were analyzed. Data from the Ambulance Victoria Data warehouse were used to perform linkage to the Victorian Cardiac Outcomes Registry for all patients transported via emergency medical services (EMS). The primary end point was EMS call‐to‐door time (prehospital system delay). Secondary end points included symptom‐to‐EMS call time (patient delay), door‐to‐device time (hospital delay), 30‐day mortality, major adverse cardiovascular events, and major bleeding. End points were analyzed according to sex and adjusted for age, comorbidities, cardiogenic shock, cardiac arrest, and symptom onset time. A total of 6330 (21% women) patients with ST‐segment–elevation myocardial infarction were transported by EMS. Compared with men, women had longer adjusted geometric mean symptom‐to‐EMS call times (47.0 versus 44.0 minutes; P<0.001), EMS call‐to‐door times (58.1 versus 55.7 minutes; P<0.001), and door‐to‐device times (58.5 versus 54.9 minutes; P=0.006). Compared with men, women had higher 30‐day mortality (odds ratio [OR], 1.38; 95% CI, 1.06–1.79; P=0.02) and major bleeding (OR, 1.54; 95% CI, 1.08–2.20; P=0.02).

Conclusions

Female patients with ST‐segment–elevation myocardial infarction experienced excess delays in patient delays, prehospital system delays, and hospital delays, even after adjustment for confounders. Prehospital system and hospital delays resulted in an adjusted excess delay of 10 minutes compared with men.

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.

The de Winter electrocardiogram pattern in a 52-year-old-male: a case report

Background 

The 12-lead electrocardiogram (ECG) remains the primary test for diagnosis of acute myocardial infarction (MI) secondary to acute coronary occlusion or near occlusion, with insufficient collateral circulation. Decisions regarding urgent reperfusion are based on whether or not there’s new ST-segment elevation. The de Winter ECG pattern is a distinct ECG pattern without any ST-segment elevation, it may be missed by anyone unfamiliar with it.

Case summary 

We present a case whose chief complaint was severe central chest pain, the patient was diagnosed with acute MI secondary to a culprit lesion in the left anterior descending artery, despite the ECG not meeting standard STEMI criteria. After the ECG’s significance was recognized by paramedics, the patient received immediate percutaneous coronary intervention with stenting and was discharged home after a brief hospital admission.

Discussion 

In some cases, acute MI presents with ECG features that do not meet the standard criteria for STEMI diagnosis. The de Winter ECG pattern is one such example. This pattern should be immediately recognizable to those responsible for the activation of the catheterization laboratory, physicians, and paramedics included.

Acute Myocardial Infarction Identified by Paramedics Using the Smith-Modified Sgarbossa Criteria: A Case Report

Identifying acute MI in the setting of left bundle branch block (LBBB) is challenging because ST-segment elevation is often found at baseline. When faced with LBBB and ischemic symptoms, identifying which patients require urgent reperfusion therapy is critical. Sgarbossa et al. derived three criteria that can be used to help identify these patients, Smith et al. refined these criteria creating the Smith-modified Sgarbossa criteria. We present a case of LBBB meeting the Smith-modified Sgarbossa criteria, recognized by paramedics and used to activate the catheterization laboratory after normal business hours. The patient was found with 95% stenosis of the left anterior descending artery and received stenting.

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.

Impact of telemedicine interventions on mortality in patients with acute myocardial infarction: a systematic review and meta-analysis

BACKGROUND

Despite the promise of telemedicine to improve care for ischaemic heart disease, there are significant obstacles to implementation. Demonstrating improvement in patient-centred outcomes is important to support development of these innovative strategies.

OBJECTIVE

To assess the impact of telemedicine interventions on mortality after acute myocardial infarction (AMI).

METHODS

Articles were searched in MEDLINE, Cochrane Central Register of Controlled Trials, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Base de Dados de Enfermagem (BDENF), Indice Bibliográfico Español en Ciencias de la Salud (IBECs), Web of Science, Scopus and Google Scholar, from January 2004 to January 2018. Study selection and data extraction were performed by two independent reviewers. In-hospital mortality (primary outcome), and door-to-balloon (DTB) time, 30-day mortality and long-term mortality (secondary outcomes) were assessed. Random effects models were applied to estimate pooled results.

RESULTS

Thirty non-randomised controlled and seven quasi-experimental studies were included (16 960 patients). They were classified as moderate or serious risk of bias by ROBINS-I (Risk Of Bias In Non-randomized Studies-of Interventions tool). In 31 studies, the intervention was prehospital ECG transmission. Telemedicine was associated with reduced in-hospital mortality compared with usual care (relative risk (RR) 0.63(95% confidence interval[CI] 0.55 to 0.72); I² <0.001%). DTB time was consistently reduced (mean difference -28 (95% CI -35 to -20) min), but showed large heterogeneity (I²=94%). Thirty-day mortality (RR 0.62;95% CI 0.43 to 0.85) and long-term mortality (RR 0.61(95% CI 0.40 to 0.92)) were also reduced, with moderate heterogeneity (I²=52%).

CONCLUSIONS

There is moderate-quality evidence that telemedicine strategies, in particular ECG transmission, combined with the usual care for AMI are associated with reduced in-hospital mortality and very-low quality evidence that they reduce DTB time, 30-day mortality and long-term mortality.

The Impact of Out-of-Hours Presentation on Clinical Outcomes in ST-Elevation Myocardial Infarction

BACKGROUND

Systems of care have been established to ensure patients with ST-elevation myocardial infarction (STEMI) get timely access to primary percutaneous coronary intervention (PPCI). In this study, we evaluated whether patients undergoing PPCI both in-hours and out-of-hours experience similar care and clinical outcomes.

METHODS

Of 9,865 patients who underwent PCI for STEMI from 2005 to 2016 and were enrolled in the multi-centre Melbourne Interventional Group registry, patients who had initially presented to a non-PCI capable hospital, received thrombolysis or presented >12hourspost-symptom onset were excluded. Our final study cohort of 4,590 patients were dichotomised by whether PPCI was performed in-hours or out-of-hours, and compared. The primary outcome was 30-day mortality.

RESULTS

The in-hours group included 1,865 patients (40.6%) while 2,725 patients (59.4%) had out-of-hours PPCI. Patients presenting out-of-hours had longer median door-to-balloon time (DTBT; 83 [IQR 61-109] vs. 60 [IQR 41-88] mins, p<0.01) and were more likely to receive a drug-eluting stent (p=0.001). Procedural characteristics were otherwise similar although rates of radial access were low overall (18.4%). No differences in in-hospital, 30-day or 12-month mortality were observed between the groups (p=NS). On Cox proportional hazards modelling, out-of-hours presentation was not an independent predictor of 30-day mortality (HR 0.94, 95% CI 0.71-1.22). A landmark analysis of data from 2012 did not change the primary outcome.

CONCLUSION

Despite a slightly longer DTBT, patients undergoing PPCI out-of-hours experienced similar care and clinical outcomes to the in-hours group. Given the majority of patients with STEMI present out-of-hours, these data have implications for STEMI systems of care.

Push Notifications Reduce Emergency Department Response Times to Prehospital ST-segment Elevation Myocardial Infarction

Introduction

Prehospital acquisition of electrocardiograms (ECG) has been consistently associated with reduced door-to-balloon times in the treatment of ST-segment myocardial infarction (STEMI). There is little evidence establishing best hospital practices once the ECG has been received by the emergency department (ED). This study evaluates the use of a push notification system to reduce delays in cardiac catheterization lab (CCL) activation for prehospital STEMI.

Methods

In this prospective before-and-after study, we collected prehospital ECGs with computer interpretation of STEMI from May 2012 to October 2013. Push notifications were implemented June 1, 2013. During the study period, we collected timestamps of when the prehospital ECG was received (email timestamp of receiving account), CCL team activation (timestamp in paging system), and patient arrival (timestamp in ED tracking board). When prehospital ECGs were received in the ED, an audible alert was played via the Vocera WiFi communication system, notifying nursing staff that an ECG was available for physician interpretation. We compared the time from receiving the ECG to activation of the CCL before and after the audible notification was implemented.

Results

Of the 56 cases received, we included 45 in our analysis (20 cases with pre-arrival CCL activation and 25 with post-arrival activation). For the pre-arrival group, the interval from ECG received to CCL activation prior to implementation was 9.1 minutes with a standard deviation (SD) of 5.7 minutes. After implementation, the interval was reduced to 3.33 minutes with a SD of 1.63 minutes. Delay was decreased by 5.8 minutes (p < 0.01). Post-implementation activation times were more consistent, demonstrated by a decrease in SD from 5.75 to 1.63 min (p < 0.01). For patients with CCL activation after arrival, there was no significant change in mean delay after implementation.

Conclusion

In this small, single-center observational study, we demonstrated that the use of push notifications to ED staff alerting that a prehospital STEMI ECG was received correlated with a small reduction in, and increased consistency of, ED CCL activation.

Effectiveness of implementation strategies for the improvement of guideline and protocol adherence in emergency care: a systematic review

OBJECTIVE

Guideline and protocol adherence in prehospital and in-hospital emergency departments (EDs) is suboptimal. Therefore, the objective of this systematic review was to identify effective strategies for improving guideline and protocol adherence in prehospital and ED settings.

DESIGN

Systematic review.

DATA SOURCES

PubMed (including MEDLINE), CINAHL, EMBASE and Cochrane.

METHODS

We selected (quasi) experimental studies published between 2004 and 2018 that used strategies to increase guideline and protocol adherence in prehospital and in-hospital emergency care. Pairs of two independent reviewers performed the selection process, quality assessment and data extraction.

RESULTS

Eleven studies were included, nine of which were performed in the ED setting and two studies were performed in a combined prehospital and ED setting. For the ED setting, the studies indicated that educational strategies as sole intervention, and educational strategies in combination with audit and feedback, are probably effective in improving guideline adherence. Sole use of reminders in the ED setting also showed positive effects. The two studies in the combined prehospital and ED setting showed similar results for the sole use of educational interventions.

CONCLUSIONS

Our review does not allow firm conclusion on how to promote guideline and protocol adherence in prehospital emergency care, or the combination of prehospital and ED care. For ED settings, the sole use of reminders or educational interventions and the use of multifaceted strategies of education combined with audit and feedback are all likely to be effective in improving guideline adherence.

Australian Trends in Procedural Characteristics and Outcomes in Patients Undergoing Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

Over the last decade, systems of care for ST-elevation myocardial infarction (STEMI) have evolved to try to improve outcomes and timely access to percutaneous coronary intervention (PCI). There have also been advances in PCI techniques and adjunctive pharmacotherapies. In this study, we sought to determine temporal changes in practices and clinical outcomes of PCI in patients with STEMI. We prospectively collected data on 8,412 consecutive patients undergoing PCI for STEMI between 2005 and 2016 in the multicenter Melbourne Interventional Group registry. Data were divided by procedure year for trends analysis. The primary end point was 30-day mortality. Patient demographics and comorbidities including smoking and diabetes have remained stable. The volume of primary PCI performed within 12 hours of symptom onset has significantly risen (65.7% to 80.1%, p < 0.01). The proportion of patients achieving the recommended door-to-balloon time ≤90 minutes has also risen (37.6% to 59.0%, p < 0.01). Patient complexity has also increased with more patients after out-of-hospital cardiac arrest with STEMI now being treated with PCI (2.6% to 9.1%, p < 0.01). A shift from mainly femoral to radial access and from bare-metal to drug-eluting stent use was seen. Glycoprotein IIb/IIIa inhibitors are being used less frequently with increasing use of newer antiplatelet agents. Thirty-day mortality has remained low throughout the study period at 6.5% overall. In conclusion, although timely access to primary PCI has improved, mortality rates have remained unchanged, but remain low and compare favorably with international data. Australian PCI practice has overall evolved in response to evidence and emergence of new adjunctive device and pharmacotherapies.

Implementation of Regional ST-Segment Elevation Myocardial Infarction Systems of Care: Successes and Challenges

Current guidelines recommend that communities create and maintain a regional system of ST-segment elevation myocardial infarction (STEMI) care that includes assessment and continuous quality improvement of emergency medical services and hospital-based activities. Availability and timely access is a challenge in many areas of the United States. This article reviews clinical trial data supporting the use of primary percutaneous coronary intervention as the optimal reperfusion strategy, and fibrinolysis as an option when this is not possible. It then describes the outcomes and benefits of implementing regional systems of STEMI care, and discusses ongoing challenges for STEMI system implementation, including inadequate data collection and feedback, and hospital and physician competition.

Ambulance smartphone tool for field triage of ruptured aortic aneurysms (FILTR): study protocol for a prospective observational validation of diagnostic accuracy

INTRODUCTION

Rupture of an abdominal aortic aneurysm (rAAA) carries a considerable mortality rate and is often fatal. rAAA can be treated through open or endovascular surgical intervention and it is possible that more rapid access to definitive intervention might be a key aspect of improving mortality for rAAA. Diagnosis is not always straightforward with up to 42% of rAAA initially misdiagnosed, introducing potentially harmful delay. There is a need for an effective clinical decision support tool for accurate prehospital diagnosis and triage to enable transfer to an appropriate centre.

METHODS AND ANALYSIS

Prospective multicentre observational study assessing the diagnostic accuracy of a prehospital smartphone triage tool for detection of rAAA. The study will be conducted across London in conjunction with London Ambulance Service (LAS). A logistic score predicting the risk of rAAA by assessing ten key parameters was developed and retrospectively validated through logistic regression analysis of ambulance records and Hospital Episode Statistics data for 2200 patients from 2005 to 2010. The triage tool is integrated into a secure mobile app for major smartphone platforms. Key parameters collected from the app will be retrospectively matched with final hospital discharge diagnosis for each patient encounter. The primary outcome is to assess the sensitivity, specificity and positive predictive value of the rAAA triage tool logistic score in prospective use as a mob app for prehospital ambulance clinicians. Data collection started in November 2014 and the study will recruit a minimum of 1150 non-consecutive patients over a time period of 2 years.

ETHICS AND DISSEMINATION

Full ethical approval has been gained for this study. The results of this study will be disseminated in peer-reviewed publications, and international/national presentations.

TRIAL REGISTRATION NUMBER

CPMS 16459; pre-results.

Survival after an acute coronary syndrome: 18-month outcomes from the Australian and New Zealand SNAPSHOT ACS study

OBJECTIVES

To assess the impact of the availability of a catheterisation laboratory and evidence-based care on the 18-month mortality rate in patients with suspected acute coronary syndromes (ACS).

DESIGN, SETTING AND PARTICIPANTS

Management and outcomes are described for patients enrolled in the 2012 Australian and New Zealand SNAPSHOT ACS audit. Patients were stratified according to their presentation to hospitals with or without cardiac catheterisation facilities. Data linkage ascertained patient vital status 18 months after admission. Descriptive and Cox proportional hazards analyses determined predictors of outcomes, and were used to estimate the numbers of deaths that could be averted by improved application of evidence-based care.

MAIN OUTCOME MEASURES

Mortality for ACS patients from admission to 18 months after admission.

RESULTS

Definite ACS patients presenting to catheterisation-capable (CC) hospitals (n = 1326) were more likely to undergo coronary angiography than those presenting to non-CC hospitals (n = 1031) (61.5% v 50.8%; P = 0.0001), receive timely reperfusion (for ST elevation myocardial infarction (STEMI) patients: 45.2% v 19.2%; P < 0.001), and be referred for cardiac rehabilitation (57% v 53%; P = 0.05). All-cause mortality over 18 months was highest for STEMI (16.2%) and non-STEMI (16.3%) patients, and lowest for those presenting with unstable angina (6.8%) and non-cardiac chest pain (4.8%; P < 0.0001 for trend). After adjustment for patient propensity to present to a CC hospital and patient risk, presentation to a CC hospital was associated with 21% (95% CI, 2%-37%) lower mortality than presentation to a non-CC hospital. This mortality difference was attenuated after adjusting for delivery of evidence-based care.

CONCLUSION

In Australia and New Zealand, the availability of a catheterisation laboratory appears to have a significant impact on long-term mortality in ACS patients, which is still substantial. This mortality may be reduced by improvements in evidence-based care in both CC and non-CC hospitals.

Current State of ST-Segment Myocardial Infarction: Evidence-based Therapies and Optimal Patient Outcomes in Advanced Systems of Care

Advances in reperfusion therapy for ST-segment elevation myocardial infarction (STEMI) provide optimal patient outcomes. Reperfusion therapies, including contemporary primary percutaneous coronary intervention, represent decades of clinical evidence development in large clinical trials and national databases. However, rapid identification of STEMI and guideline-directed management of patients across broad populations have been best achieved in advanced systems of care. Current outcomes in STEMI reflect the evolution of both clinical data and idealized health care delivery networks.

Importance of hospital entry: walk-in STEMI and primary percutaneous coronary intervention

INTRODUCTION

Patients with ST elevation myocardial infarction (STEMI) require rapid identification and triage to initiate reperfusion therapy. Walk-in STEMI patients have longer treatment times compared to emergency medical service (EMS) transported patients. While effective triage of large numbers of critically ill patients in the emergency department is often cited as the reason for treatment delays, additional factors have not been explored. The purpose of this study was to evaluate baseline demographic and clinical differences between walk-in and EMS-transported STEMI patients and identify factors associated with prolonged door to balloon (D2B) time in walk-in STEMI patients.

METHODS

We performed a retrospective review of 136 STEMI patients presenting to an urban academic teaching center from January 2009 through December 2010. Baseline demographics, mode of hospital entry (walk-in versus EMS transport), treatment times, angiographic findings, procedures performed and in-hospital clinical events were collected. We compared walk-in and EMS-transported STEMI patients and identified independent factors of prolonged D2B time for walk-in patients using stepwise logistic regression analysis.

RESULTS

Walk-in patients (n=51) were more likely to be Latino and presented with a higher heart rate, higher systolic blood pressure, prior history of diabetes mellitus and were more likely to have an elevated initial troponin value, compared to EMS-transported patients. EMS-transported patients (n=64) were more likely to be white and had a higher prevalence of left main coronary artery disease, compared to walk-in patients. Door to electrocardiogram (ECG), ECG to catheterization laboratory (CL) activation and D2B times were significantly longer for walk-in patients. Walk-in patients were more likely to have D2B time >90 minutes, compared to EMS- transported patients; odds ratio 3.53 (95% CI 1.03, 12.07), p=0.04. Stepwise logistic regression identified hospital entry mode as the only independent predictor for prolonged D2B time.

CONCLUSION

Baseline differences exist between walk-in and EMS-transported STEMI patients undergoing primary percutaneous coronary intervention (PCI). Hospital entry mode was the most important predictor for prolonged treatment times for primary PCI, independent of age, Latino ethnicity, heart rate, systolic blood pressure and initial troponin value. Prolonged door to ECG and ECG to CL activation times are modifiable factors associated with prolonged treatment times in walk-in STEMI patients. In addition to promoting the use of EMS transport, efforts are needed to rapidly identify and expedite the triage of walk-in STEMI patients.

Proposed Recommendations for Myocardial Revascularisation

This discussion paper presents proposed recommendations for myocardial revascularisation in the Australasian clinical setting based on underlying evidence-based principles and an understanding of local factors which may limit the provision of ideal practice. Recommendations are proposed for myocardial revascularisation in common clinical scenarios and also for special categories, such as patients with diabetes, chronic renal impairment, advanced age, chronic total occlusions and Indigenous patients.

The impact on long term health outcomes for STEMI patients during a period of process change to reduce door to balloon time

BACKGROUND

Guidelines for the management of ST-segment elevation myocardial infarction (STEMI) recommend a 'door to balloon time' (DTBT) within 90 minutes. It is unclear whether strategies to reduce DTBT translate to improved longer-term health outcomes for STEMI patients.

AIMS

This study sought to determine whether implemented strategies to improve timely management of STEMI reduced DTBT and impacted upon health outcomes such as length of stay, unplanned readmission and 12-month mortality. Predictors of timely management for STEMI were also examined.

METHODS

A five-year review was undertaken on primary percutaneous coronary intervention for STEMI in one tertiary hospital. Comparisons were made between process change groups and DTBT. Logistic regression identified predictors of timely management.

RESULTS

470 STEMI patients underwent immediate primary percutaneous coronary intervention. Process change improved the median DTBT (109 min vs. 72 min, p<0.001) with no significant effect on length of stay (p=0.83), unplanned cardiac readmissions (p=0.68) or 12-month mortality (9.0% vs. 8.6%, p=0.64). Those receiving timely treatment (i.e. DTBT< 90 min) were younger (p<0.05), male (p<0.03), presented via ambulance (p<0.004), during business hours (p<0.0001) and had a lower Thrombolysis In Myocardial Infarction score (p<0.006). Timely treatment was associated with lower 12-month mortality (3.7% vs. 15.7%, p<0.0001) and increased uptake of inpatient cardiac rehabilitation (p<0.005), with length of stay and unplanned readmission similar between groups (p=NS).

CONCLUSIONS

Process changes improved DTBT but had no effect on length of stay, readmission rate or 12-month mortality. Yet, timely management was critical to 12-month outcomes. Further studies are required to explore the barriers to timely treatment.

Computerized interpretation of the prehospital electrocardiogram: predictive value for ST segment elevation myocardial infarction and impact on on-scene time

Introduction:

Computerized interpretation of the prehospital electrocardiogram (ECG) is increasingly being used in the basic life support (BLS) ambulance setting to reduce delays to treatment for patients suspected of ST segment elevation myocardial infarction (STEMI).

Objectives:

To estimate 1) predictive values of computerized prehospital 12-lead ECG interpretation for STEMI and 2) additional on-scene time for 12-lead ECG acquisition.

Methods:

Over a 2-year period, 1,247 ECGs acquired by primary care paramedics for suspected STEMI were collected. ECGs were interpreted in real time by the GEMarquette 12SL ECG analysis program. Predictive values were estimated with a bayesian latent class model incorporating the computerized ECG interpretations, consensus ECG interpretations by study cardiologists, and hospital diagnosis. On-scene time was compared for ambulance-transported patients with (n 5 985) and without (n 5 5,056) prehospital ECGs who received prehospital aspirin and/or nitroglycerin.

Results:

The computer's positive and negative predictive values for STEMI were 74.0% (95% credible interval [CrI] 69.6–75.6) and 98.1% (95% CrI 97.8–98.4), respectively. The sensitivity and specificity were 69.2% (95% CrI 59.0–78.5) and 98.9% (95% CrI 98.1–99.4), respectively. Prehospital ECGs were associated with a mean increase in on-scene time of 5.9 minutes (95% confidence interval 5.5–6.3).

Conclusions:

The predictive values of the computerized prehospital ECG interpretation appear to be adequate for diversion programs that direct patients with a positive result to hospitals with angioplasty facilities. The estimated 26.0% chance that a positive interpretation is false is likely too high for activation of a catheterization laboratory from the field. Acquiring prehospital ECGs does not substantially increase on-scene time in the BLS setting.

Development of a postgraduate interventional cardiac nursing curriculum

Interventional cardiology practices have advanced immensely in the last two decades, but the educational preparation of the workforce in cardiac catheter laboratories has not seen commensurate changes. Although on-the-job training has sufficed in the past, recognition of this workforce as a specialty practice domain now demands specialist educational preparation. The aim of this paper is to present the development of an interventional cardiac nursing curriculum nested within a Master of Nursing Practice in Australia. International and national health educational principles, teaching and learning theories and professional frameworks and philosophies are foundational to the program designed for interventional cardiac specialist nurses. These broader health, educational and professional underpinnings will be described to illustrate their application to the program's theoretical and clinical components. Situating interventional cardiac nursing within a Master's degree program at University provides nurses with the opportunities to develop high level critical thinking and problem solving knowledge and skills.

The impact of telemedicine in cardiac critical care

Telemedicine was recognized in the 1970s as a legitimate entity for applying the use of modern information and communications technologies to the delivery of health services. Telecardiology is one of the fastest growing fields in telemedicine. The advancement of technologies and Web-based applications has allowed better transmission of health care delivery. This article discusses current advancements, the scope of telemedicine in cardiology, and its application to the critically ill. The impact of telecardiology consultation continues to evolve and includes many promising applications with potential positive implications for admission rates, morbidity, and mortality.

Trends in door-to-balloon time and outcomes following primary percutaneous coronary intervention for ST-elevation myocardial infarction: an Australian perspective

BACKGROUND

Guidelines for patients with ST-elevation myocardial infarction include a door-to-balloon time (DTBT) of ≤90 min for primary percutaneous coronary intervention.

AIM

The aim of this study was to assess temporal trends (2006-2010) in DTBT and determine if a reduction in DTBT was associated with improved clinical outcomes.

METHODS

We compared annual median DTBT in 1926 STEMI patients undergoing primary percutaneous coronary intervention from the Melbourne Interventional Group registry. ST-elevation myocardial infarction presenting >12 h and rescue percutaneous coronary intervention was excluded. Major adverse cardiac events were analysed according to DTBT (dichotomised as ≤90 min vs >90 min). A multivariable analysis for predictors of mortality (including DTBT) was performed.

RESULTS

Baseline demographics, clinical and procedural characteristics were similar in the STEMI cohort across the 5 years, apart from an increase in out-of-hospital cardiac arrest (3.6% in 2006 vs 9.4% in 2010, P < 0.0001) and cardiogenic shock (7.7-9.6%, P = 0.07). The median DTBT (interquartile range) was reduced from 95 (74-130) min in 2006 to 75 (51-100) min in 2010 (P < 0.01). In this period, the proportion of patients achieving a DTBT of ≤90 min increased from 45% to 67% (P < 0.01). Lower mortality and major adverse cardiac event rates were observed with DTBT ≤90 min (all P < 0.01). Multivariable analysis showed that a DTBT of ≤90 min was associated with improved clinical outcomes at 12 months (odds ratio 0.48; 95% confidence interval 0.33-0.73, P < 0.01).

CONCLUSION

There has been a decline in median DTBT in the Melbourne Interventional Group registry over 5 years. DTBT of ≤90 min is associated with improved clinical outcomes at 12 months.

A review of a regional primary percutaneous coronary intervention service, with a focus on door to reperfusion times: the 2012 Auckland/Northland experience

AIMS

Primary percutaneous coronary intervention (PCI) is the optimal management for ST segment elevation myocardial infarction (STEMI) patients. We reviewed the largest primary PCI regional service in New Zealand: the Auckland/Northland service based at Auckland City Hospital, to assess patient management, in particular the door to reperfusion times (DTRTs), and predictors of death in hospital.

METHODS

We obtained patient details from a comprehensive prospective database of all primary PCI patients admitted with STEMI from 1/1/12 to 31/12/12 to the Auckland City Hospital cardiac catheterisation laboratory. Of four District Health Boards (DHBs) within the region, two accessed this regional service at all times, and two accessed the Auckland City Hospital cardiac catheterisation laboratory 'after hours': all times except for 08:00 to 16:00 hours on Monday to Friday.

RESULTS

A total of 401 adult patients underwent a primary PCI at the Auckland City Hospital Regional centre for a STEMI presentation, over the 12 months period. The median patient age was 61 years, 77% were male. Overall 183 (46%) (95% CI 41, 51) patients achieved a DTRT of < 90 mins, and 266 (66%) (95% CI 61, 71) a DTRT of < 120 mins, with a clear geographical influence to these times. Of 27 patients with direct transfer to the catheter laboratory from the community, the DTRT was < 120 mins in 24 (92%) (95% CI 72, 96) patients. In-hospital mortality was 24 (6%) patients (95% CI 4, 9).

CONCLUSIONS

The 2012 Auckland/Northland primary PCI service delivers good outcomes consistent with current Australasian standards. Although geographical isolation complicates door to reperfusion times, these may potentially be improved by more focus on direct transfer to the cardiac catheterisation laboratory, especially directly from the community.

Current state of ST-segment myocardial infarction: evidence-based therapies and optimal patient outcomes in advanced systems of care

Advances in reperfusion therapy for ST-segment elevation myocardial infarction (STEMI) provide optimal patient outcomes. Reperfusion therapies, including contemporary primary percutaneous coronary intervention, represent decades of clinical evidence development in large clinical trials and national databases. However, rapid identification of STEMI and guideline-directed management of patients across broad populations have been best achieved in advanced systems of care. Current outcomes in STEMI reflect the evolution of both clinical data and idealized health care delivery networks.

System dynamics modeling in the evaluation of delays of care in ST-segment elevation myocardial infarction patients within a tiered health system

Background

Mortality rates amongst ST segment elevation myocardial infarction (STEMI) patients remain high, especially in developing countries. The aim of this study was to evaluate the factors related with delays in the treatment of STEMI patients to support a strategic plan toward structural and personnel modifications in a primary hospital aligning its process with international guidelines.

Methods and Findings

The study was conducted in a primary hospital localized in Foz do Iguaçu, Brazil. We utilized a qualitative and quantitative integrated analysis including on-site observations, interviews, medical records analysis, Qualitative Comparative Analysis (QCA) and System Dynamics Modeling (SD). Main cause of delays were categorized into three themes: a) professional, b) equipment and c) transportation logistics. QCA analysis confirmed four main stages of delay to STEMI patient’s care in relation to the ‘Door-in-Door-out’ time at the primary hospital. These stages and their average delays in minutes were: a) First Medical Contact (From Door-In to the first contact with the nurse and/or physician): 7 minutes; b) Electrocardiogram acquisition and review by a physician: 28 minutes; c) ECG transmission and Percutaneous Coronary Intervention Center team feedback time: 76 minutes; and d) Patient’s Transfer Waiting Time: 78 minutes. SD baseline model confirmed the system’s behavior with all occurring delays and the need of improvements. Moreover, after model validation and sensitivity analysis, results suggested that an overall improvement of 40% to 50% in each of these identified stages would reduce the delay.

Conclusions

This evaluation suggests that investment in health personnel training, diminution of bureaucracy, and management of guidelines might lead to important improvements decreasing the delay of STEMI patients’ care. In addition, this work provides evidence that SD modeling may highlight areas where health system managers can implement and evaluate the necessary changes in order to improve the process of care.

Electrocardiograhic findings resulting in inappropriate cardiac catheterization laboratory activation for ST-segment elevation myocardial infarction

BACKGROUND

Prompt reperfusion has been shown to improve outcomes in patients with acute ST-segment elevation myocardial infarction (STEMI) with a goal of culprit vessel patency in <90 minutes. This requires a coordinated approach between the emergency medical services (EMS), emergency department (ED) and interventional cardiology. The urgency of this process can contribute to inappropriate cardiac catheterization laboratory (CCL) activations.

OBJECTIVES

One of the major determinants of inappropriate activations has been misinterpretation of the electrocardiogram (ECG) in the patient with acute chest pain.

METHODS

We report the ECG findings for all CCL activations over an 18-month period after the inception of a STEMI program at our institution.

RESULTS

There were a total of 139 activations with 77 having a STEMI diagnosis confirmed and 62 activations where there was no STEMI. The inappropriate activations resulted from a combination of atypical symptoms and misinterpretation of the ECG (45% due to anterior ST-segment elevation) on patient presentation. The electrocardiographic abnormalities were particularly problematic in African-Americans with left ventricular hypertrophy.

CONCLUSIONS

In this single-center, prospective observational study, nearly half of the inappropriate STEMI activations were due to the misinterpretation of anterior ST-segment elevation and this finding was commonly seen in African-Americans with left ventricular hypertrophy.

Prehospital telemedicine electrocardiogram triage for a regional public emergency medical service: is it worth it? A preliminary cost analysis

BACKGROUND

Telemedicine has been shown to improve quality of health-care delivery in several fields of medicine; its cost-effectiveness, however, is still a matter of debate.

HYPOTHESIS

Pre-hospital telemedicine electrocardiogram triage for regional public emergency medical service may reduce costs.

METHODS

An economic evaluation (cost analysis) was performed from the perspective of regional health-care system. Patients enrolled in the study and considered for cost analysis were those who called the local emergency medical service (EMS; dialing 1-1-8) during 2012 and underwent prehospital field triage with a telemedicine electrocardiogram (ECG) in the case of suspected acute cardiac disease (acute coronary syndrome, arrhythmia). The prehospital ECGs were read by a remote cardiologist, available 24/7. Cost savings associated with this method were calculated by subtracting the cost of prehospital triage with telemedicine support from the cost of conventional emergency department triage (ECG and consultation by a cardiologist).

RESULTS

During 2012, the regional EMS performed 109 750 ECGs by telemedicine support. The associated total cost for the regional health-care system was €1 833 333, with a €16.70 cost per single ECG/consultation. Given the cost of similar conventional emergency department treatment from a regional rate list of €24.80 to €55.20, the savings was €8.10 to €38.40 per ECG/consultation (total savings, €891 759.50 to €4 219 379.50). The cost for ruling out an acute cardiac disease was €25.30; for a prehospital diagnosis of cardiovascular disease, €49.20. With 629 prehospital diagnoses of ST-elevation myocardial infarction and reported reductions in mortality thanks to prehospital diagnosis deduced from prior studies, 69 lives per year presumably could be saved, with a cost per quality-adjusted life year gained of €1927, €990/€ - 2508 after correction for potential savings.

CONCLUSIONS

Prehospital EMS triage with telemedicine ECG in patients with suspected acute cardiac disease may reduce health-care costs.

Contemporary themes in acute coronary syndrome management: from acute illness to secondary prevention

Acute coronary syndrome (ACS; myocardial infarction and unstable angina) is the leading cause of mortality in Australia, and those who survive one ACS event are at significant risk of experiencing another. Access to evidence-based and optimal ACS management in both the acute and long-term periods is of great importance. Management of ACS should include appropriate timely revascularisation, medical therapy and ongoing secondary prevention. A key consideration in selecting acute antithrombotic therapies is a careful determination of the risk of bleeding versus risk of recurrent ischaemia. Although there is a strong evidence base for the urgency of delivery and the quality of acute care, knowledge translation is suboptimal. There remains a need for ongoing research and policy development aimed at improving ease and equity of access to evidence-based care. Despite universal guideline recommendations for ongoing secondary prevention strategies, research indicates suboptimal use of evidence-based medications, poor adherence to lifestyle recommendations, and low levels of participation in traditional cardiac rehabilitation. Contemporary secondary prevention programs are evolving into flexible, multifaceted interventions to provide maximal clinical benefits to a majority of patients.