Artificial neural networks for ECG interpretation in acute coronary syndrome: A scoping review.

INTRODUCTION: The electrocardiogram (ECG) is a crucial diagnostic tool in the Emergency Department (ED) for assessing patients with Acute Coronary Syndrome (ACS). Despite its widespread use, the ECG has limitations, including low sensitivity of the STEMI criteria to detect Acute Coronary Occlusion (ACO) and poor inter-rater reliability. Emerging ECG features beyond the traditional STEMI criteria show promise in improving early ACO diagnosis, but complexity hinders widespread adoption. The potential integration of Artificial Neural Networks (ANN) holds promise for enhancing diagnostic accuracy and addressing reliability issues in ECG interpretation for ACO symptoms. METHODS: Ovid MEDLINE, CINAHL, EMBASE, Cochrane, PubMed and Scopus were searched from inception through to 8th of December 2023. A thorough search of the grey literature and reference lists of relevant articles was also performed to identify additional studies. Articles were included if they reported the use of ANN for ECG interpretation of Acute Coronary Syndrome in the Emergency Department patients. RESULTS: The search yielded a total of 244 articles. After removing duplicates and excluding non-relevant articles, 14 remained for analysis. There was significant heterogeneity in the types of ANN models used and the outcomes assessed, making direct comparisons challenging. Nevertheless, ANN appeared to demonstrate higher accuracy than physician interpreters for the evaluated outcomes and this proved independent of both specialty and years of experience. CONCLUSIONS: The interpretation of ECGs in patients with suspected ACS using ANN appears to be accurate and potentially superior when compared to human interpreters and computerised algorithms. This appears consistent across various ANN models and outcome variables. Future investigations should emphasise ANN interpretation of ECGs in patients with ACO, where rapid and accurate diagnosis can significantly benefit patients through timely access to reperfusion therapies.

Outcomes of adult patients discharged at scene by emergency medical services.

BACKGROUND: The outcomes of patients who call an ambulance but are discharged at scene reflect the safety and quality of emergency medical service (EMS) care. While previous studies have examined the outcomes of patients discharged at scene, none have specifically focused on paramedic-initiated discharge. This study aims to describe the outcomes of adult patients discharged at scene by paramedics and identify factors associated with 72-hour outcomes. METHODS: This was a retrospective data linkage study on consecutive adult EMS patients discharged at scene by paramedics in Victoria, Australia, between 1 January 2015 and 30 June 2019. Multivariable logistic regression was used to investigate factors associated with EMS recontact, ED presentation, hospital admission and serious adverse events (death, cardiac arrest, category 1 triage or intensive care unit admission) within 72 hours of the initial emergency call. RESULTS: There were 375 758 cases of adults discharged at scene following EMS attendance, of which 222 571 (59.2%) were paramedic-initiated decisions. Of these, 6.8% recontacted EMS, 5.0% presented to ED, 2.4% were admitted to hospital and 0.3% had a serious adverse event in the following 72 hours. The odds of EMS recontact were increased in cases related to mental health (adjusted OR (AOR) 1.41 (95% CI 1.33 to 1.49)), among low-income government concession holders (AOR 1.61 (95% CI 1.55 to 1.67)) and in areas of low socioeconomic advantage (AOR 1.19 (95% CI 1.13 to 1.25)). The odds of hospital admission were increased in cases related to infection (AOR 3.14 (95% CI 2.80 to 3.52)) and pain (AOR 1.93 (95% CI 1.75 to 2.14)). The strongest driver of serious adverse events was an abnormal vital sign (AOR 4.81 (95% CI 3.87 to 5.98)). CONCLUSION: The occurrence of hospital admission and adverse events is rare in those discharged at scene, suggesting generally safe decision-making. However, increased attention to elderly, multimorbid patients or patients with infection and pain is recommended, as is further research examining the use of tools to aid paramedic recognition of potential for deterioration.

Prevalence and Predictors of Emergency Medical Service Use in Patients Undergoing Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction.

AIM: We aim to describe prevalence of Emergency Medical Service (EMS) use, investigate factors predictive of EMS use, and determine if EMS use predicts treatment delay and mortality in our ST-elevation myocardial infarction (STEMI) cohort. METHOD: We prospectively collected data on 5,602 patients presenting with STEMI for primary percutaneous coronary intervention (PCI) transported to PCI-capable hospitals in Victoria, Australia, from 2013-2018 who were entered into the Victorian Cardiac Outcomes Registry (VCOR). We linked this dataset to the Ambulance Victoria and National Death Index (NDI) datasets. We excluded late presentation, thrombolysed, and in-hospital STEMI, as well as patients presenting with cardiogenic shock and out-of-hospital cardiac arrest. RESULTS: In total, 74% of patients undergoing primary PCI for STEMI used EMS. Older age, female gender, higher socioeconomic status, and a history of prior ischaemic heart disease were independent predictors of using EMS. EMS use was associated with shorter adjusted door-to-balloon (53 vs 72 minutes, p<0.001) and symptom-to-balloon (183 vs 212 minutes, p<0.001) times. Mode of transport was not predictive of 30-day or 12-month mortality. CONCLUSIONS: EMS use in Victoria is relatively high compared with internationally reported data. EMS use reduces treatment delay. Predictors of EMS use in our cohort are consistent with those prevalent in prior literature. Understanding the patients who are less likely to use EMS might inform more targeted education campaigns in the future.

Effect of COVID-19 Pandemic Lockdown on Emergency Medical Service Utilisation, and Percutaneous Coronary Intervention Volume-An Australian Perspective.

BACKGROUND: Acute coronary syndrome (ACS) admissions and percutaneous coronary intervention (PCI) volume declined during periods of COVID-19 lockdown internationally in 2020. The effect of lockdown on emergency medical service (EMS) utilisation, and PCI volume during the initial phase of the pandemic in Australia has not been well described. METHOD: We analysed data from the Victorian Cardiac Outcomes Registry (VCOR), a state-wide PCI registry, linked with the Ambulance Victoria EMS registry. PCI volume, 30-day major adverse cardiovascular and cerebrovascular events (MACCE; composite of mortality, myocardial infarction, stent thrombosis, unplanned revascularisation, and stroke), and EMS utilisation were compared over four time periods: lockdown (26 Mar 2020-12 May 2020); pre-lockdown (26 Feb 2020-25 Mar 2020); post-lockdown (13 May 2020-10 Jul 2020); and the year prior (26 Mar 2019-12 May 2019). Interrupted time series analysis was performed to assess PCI trends within and between consecutive periods. RESULTS: The EMS utilisation for ACS during lockdown was higher compared with other periods: lockdown 39.4% vs pre-lockdown 29.7%; vs post-lockdown 33.6%; vs year prior 27.1%; all p<0.01. Median daily PCI cases were similar: 31 (IQR 10, 38) during lockdown; 39 (15, 49) pre-lockdown; 39.5 (11, 44) post-lockdown; and, 42 (10, 49) the year prior; all p>0.05. Median door-to-procedure time for ACS indication during lockdown was shorter at 3 hours (1.2, 20.6) vs pre-lockdown 3.9 (1.7, 21); vs post-lockdown 3.5 (1.5, 21.26); and, the year prior 3.5 (1.5, 23.7); all p<0.05. Lockdown period was associated with lower odds for 30-day MACCE compared to pre-lockdown (odds ratio [OR] 0.55 [0.33-0.93]; p=0.026); post-lockdown (OR 0.66; [0.40-1.06]; p=0.087); and the year prior (OR 0.55 [0.33-0.93]; p=0.026). CONCLUSIONS: Contrary to international trends, EMS utilisation for ACS increased during lockdown but PCI volumes remained similar throughout the initial stages of the pandemic in Victoria, with no observed adverse effect on 30-day MACCE during lockdown. These data suggest that the public health response in Victoria was not associated with poorer quality cardiovascular care in patients receiving PCI.

Acute Severe Behavioral Disturbance Requiring Parenteral Sedation in Pediatric Mental Health Presentations to Emergency Medical Services: A Retrospective Chart Review.

STUDY OBJECTIVES: To describe the epidemiological factors of mental health presentations in young people to emergency medical services (EMS) and define those experiencing acute severe behavioral disturbance by reviewing parenteral sedation use. METHODS: We performed a retrospective review of records of EMS attendance for young people (aged <18 years) with mental health presentations between July 2018 and June 2019 to a statewide EMS system in Australia of a population of 6.5 million persons. In addition, epidemiological data and information about parenteral sedation for acute severe behavioral disturbance and any adverse events were extracted from the records and analyzed. RESULTS: A total of 7,816 patients had mental health presentations with a median age of 15 years (IQR 14-17). The majority (60%) were female. These presentations accounted for 14% of all pediatric presentations to EMS. Out of them, 612 (8%) received parenteral sedation for acute severe behavioral disturbance. A number of factors were associated with increased odds of parenteral sedative medication being used, including autism spectrum disorder (odds ratio [OR] 3.3; confidence interval [CI], 2.7 to 3.9), posttraumatic stress disorder (OR 2.8; CI, 2.2 to 3.5) and intellectual disability (OR 3.6; CI, 2.6 to 4.8). The majority (460, 75%) of young people received midazolam as their first-line medication, with the remaining patients being provided ketamine (152, 25%). No serious adverse events were noted. CONCLUSION: Mental health conditions were a common presentation to EMS. A history of autism spectrum disorder, posttraumatic stress disorder, or an intellectual disability increased the odds of receiving parenteral sedation for acute severe behavioral disturbance. Sedation appears generally safe in the out-of-hospital setting.

Outcomes of paediatric patients who are not transported to hospital by Emergency Medical Services: a data linkage study.

BACKGROUND: Data on the safety of non-transport decisions for paediatric patients attended by Emergency Medical Services (EMS) are lacking. We describe the characteristics and outcomes of paediatric non-transported patients in Victoria, Australia. METHODS: A retrospective data linkage study of consecutive paediatric (aged <18 years) non-transported patients between January 2015 and June 2019. Patients were linked to ED, hospital admission and death records. Multivariable logistic regression analyses were used to determine factors associated with EMS recontact, ED presentation, hospital admission and an adverse event (death/cardiac arrest, intensive care unit admission or highest ED triage category) within 48 hours of the initial emergency call. RESULTS: In total, 62 975 non-transported patients were included. The mean age was 7.1 (SD 6.0) years and 48.9% were male. Overall, 2.2% recontacted the EMS within 48 hours, 13.7% self-presented to a public ED, 2.4% were admitted to hospital and 0.1% had an adverse event, including two deaths. Among patients with paramedic-initiated non-transport (excluding transport refusals and transport via other means), 5.6% presented to a public ED, 1.1% were admitted to hospital and 0.05% had an adverse event. In the overall population, an abnormal vital sign on initial assessment increased the odds of hospital admission and an adverse event. Among paramedic-initiated non-transports, cases occurring in the early hours of the morning (04:00-08:00 hours) were associated with increased odds of subsequent hospital admission, while the odds of ED presentation and hospital admission also increased with increasing prior exposure to non-transported cases. CONCLUSION: Adverse events were rare among paramedic-initiated non-transport cases. Vital sign derangements and attendance by paramedics with higher prior exposure to non-transports were associated with poorer outcomes and may be used to improve safety.

Healthcare cost burden of acute chest pain presentations.

BACKGROUND: This study aimed to estimate the direct healthcare cost burden of acute chest pain attendances presenting to ambulance in Victoria, Australia, and to identify key cost drivers especially among low-risk patients. METHODS: State-wide population-based cohort study of consecutive adult patients attended by ambulance for acute chest pain with individual linkage to emergency and hospital admission data in Victoria, Australia (1 January 2015-30 June 2019). Direct healthcare costs, adjusted for inflation to 2020-2021 ($A), were estimated for each component of care using a casemix funding method. RESULTS: From 241 627 ambulance attendances for chest pain during the study period, mean chest pain episode cost was $6284, and total annual costs were estimated at $337.4 million ($68 per capita per annum). Total annual costs increased across the period ($310.5 million in 2015 vs $384.5 million in 2019), while mean episode costs remained stable. Cardiovascular conditions (25% of presentations) were the most expensive (mean $11 523, total annual $148.7 million), while a non-specific pain diagnosis (49% of presentations) was the least expensive (mean $3836, total annual $93.4 million). Patients classified as being at low risk of myocardial infarction, mortality or hospital admission (Early Chest pain Admission, Myocardial infarction, and Mortality (ECAMM) score) represented 31%-57% of the cohort, with total annual costs estimated at $60.6 million-$135.4 million, depending on the score cut-off used. CONCLUSIONS: Total annual costs for acute chest pain presentations are increasing, and a significant proportion of the cost burden relates to low-risk patients and non-specific pain. These data highlight the need to improve the cost-efficiency of chest pain care pathways.

Impact of prehospital opioid dose on angiographic and clinical outcomes in acute coronary syndromes.

BACKGROUND: An adverse interaction whereby opioids impair and delay the gastrointestinal absorption of oral P2Y12 inhibitors has been established, however the clinical significance of this in acute coronary syndrome (ACS) is uncertain. We sought to characterise the relationship between prehospital opioid dose and clinical outcomes in patients with ACS. METHODS: Patients given opioid treatment by emergency medical services (EMS) with ACS who underwent percutaneous coronary intervention (PCI) between 1 January 2014 and 31 December 2018 were included in this retrospective cohort analysis using data linkage between the Ambulance Victoria, Victorian Cardiac Outcomes Registry and Melbourne Interventional Group databases. Patients with cardiogenic shock, out-of-hospital cardiac arrest and fibrinolysis were excluded. The primary end point was the risk-adjusted odds of 30-day major adverse cardiac events (MACE) between patients who received opioids and those that did not. RESULTS: 10 531 patients were included in the primary analysis. There was no significant difference in 30-day MACE between patients receiving opioids and those who did not after adjusting for key patient and clinical factors. Among patients with ST-elevation myocardial infarction (STEMI), there were significantly more patients with thrombolysis in myocardial infarction (TIMI) 0 or 1 flow pre-PCI in a subset of patients with high opioid dose versus no opioids (56% vs 25%, p<0.001). This remained significant after adjusting for known confounders with a higher predicted probability of TIMI 0/1 flow in the high versus no opioid groups (33% vs 11%, p<0.001). CONCLUSIONS: Opioid use was not associated with 30-day MACE. There were higher rates of TIMI 0/1 flow pre-PCI in patients with STEMI prescribed opioids. Future prospective research is required to verify these findings and investigate alternative analgesia for ischaemic chest pain.

Declining Public Awareness of Heart Attack Warning Symptoms in the Years Following an Australian Public Awareness Campaign: A Cross-Sectional Study.

BACKGROUND: The National Heart Foundation of Australia's (NHFA) Warning Signs campaign ran between 2010 and 2013. This study examines trends in Australian adults' ability to name heart attack symptoms during the campaign and in the years following. METHODS: Using the NHFA's HeartWatch data (quarterly online surveys) for adults aged 30-59 years, we conducted an adjusted piecewise regression analysis comparing trends in the ability to name symptoms during the campaign period plus one year lag (2010-2014) to the post-campaign period (2015-2020) RESULTS: Over the study period, there were 101,936 Australian adults surveyed. Symptom awareness was high or increased during the campaign period. However, there was a significant downward trend in each year following the campaign period for most symptoms (e.g., chest pain: adjusted odds ratio [AOR] =0.91, 95%CI: 0.56-0.80; arm pain: AOR=0.92, 95%CI: 0.90-0.94). Conversely, the inability to name any heart attack symptom increased in each year following the campaign (3.7% in 2010 to 19.9% in 2020; AOR=1.13, 95%CI: 1.10-1.15); these respondents were more likely to be younger, male, have less than 12 years of education, identify as Aboriginal and/or Torres Strait Islander Peoples, speak a language other than English at home and have no cardiovascular risk factors. CONCLUSION: Awareness of heart attack symptoms has decreased in the years since the Warning Signs campaign in Australia, with 1 in 5 adults currently unable to name a single heart attack symptom. New approaches are needed to promote and sustain this knowledge, and to ensure people act appropriately and promptly if symptoms occur.

Variation in Health Care Processes, Quality and Outcomes According to Day and Time of Chest Pain Presentation via Ambulance.

BACKGROUND: Previous studies examining temporal variations in cardiovascular care have largely been limited to assessing weekend and after-hours effects. We aimed to determine whether more complex temporal variation patterns might exist in chest pain care. METHODS: This was a population-based study of consecutive adult patients attended by emergency medical services (EMS) for non-traumatic chest pain without ST elevation in Victoria, Australia between 1 January 2015 and 30 June 2019. Multivariable models were used to assess whether time of day and week stratified into 168 hourly time periods was associated with care processes and outcomes. RESULTS: There were 196,365 EMS chest pain attendances; mean age 62.4 years (standard deviation [SD] 18.3) and 51% females. Presentations demonstrated a diurnal pattern, a Monday-Sunday gradient (Monday peak) and a reverse weekend effect (lower rates on weekends). Five temporal patterns were observed for care quality and process measures, including a diurnal pattern (longer emergency department [ED] length of stay), an after-hours pattern (lower angiography or transfer for myocardial infarction, pre-hospital aspirin administration), a weekend effect (shorter ED clinician review, shorter EMS off-load time), an afternoon/evening peak period pattern (longer ED clinician review, longer EMS off-load time) and a Monday-Sunday gradient (ED clinician review, EMS offload time). Risk of 30-day mortality was associated with weekend presentation (Odds ratio [OR] 1.15, p=0.001) and morning presentation (OR 1.17, p<0.001) while risk of 30-day EMS reattendance was associated with peak period (OR 1.16, p<0.001) and weekend presentation (OR 1.07, p<0.001). CONCLUSIONS: Chest pain care demonstrates complex temporal variation beyond the already established weekend and after-hours effect. Such relationships should be considered during resource allocation and quality improvement programs to improve care across all days and times of the week.

Prevalence of Multiple Causes of Death Within Young and Middle-Aged People Experiencing Sudden Cardiac Arrest.

BACKGROUND: Multiple causes of death are increasingly reported, particularly in older populations. Rates of multiple causes of young sudden death have not been quantified. METHOD: The End Unexplained Cardiac Death (EndUCD) registry was utilised to identify cases of young sudden death (aged 1-50 years) referred for forensic assessment from April 2019 to April 2022. Causes of death were coded according to whether one or more underlying causes of death were identified. Patients were compared according to the number of causes of death, with significant predictors assessed using logistic regression analysis. RESULTS: 1,085 cases of sudden death were identified. 263 (24.2%) cases had more than one competing cause of their sudden death. The most common multi-causal associations identified were dual non-cardiac causes of the sudden death (n=68), cardiomyopathy with non-cardiac event (n=64) and coronary artery disease with non-cardiac cause (n=63). Multi-causal death was more common in those undergoing comprehensive autopsy examination (95.8% vs 77.6%, p<0.0001), and in the setting of higher body mass index (median 31.3 kg/m2 vs 29.9 kg/m2, p=0.01), older age (44.3 years vs 41.4 years, p<0.0001), non-ventricular cardiac arrest rhythm (93.2% vs 87.3%, p=0.009), and smoking (22.8% vs 14.2%, p=0.001). The strongest predictor of multiple pathologies was comprehensive autopsy examination compared with external inspection, full-body post-mortem computed tomography and review of ancillary documentation and investigations (odds ratio 6.49, 95% confidence interval 3.47-12.14). CONCLUSIONS: One-quarter of young sudden deaths have more than one underlying cause, highlighting the value of comprehensive investigations including autopsy. Awareness of the complexity of young sudden death is important, along with multidisciplinary involvement to ensure all contributors to death are identified.

Sex differences in prehospital analgesia in patients presenting with acute coronary syndromes and their association with clinical outcomes.

OBJECTIVES: This study examined if sex differences in prehospital pain scores, opioid administration, and clinical outcomes exist in acute coronary syndrome (ACS) patients. BACKGROUND: Sex differences persist in ACS presentation, management, and outcomes. The impact of sex differences on prehospital pain management of ACS with opioids is unknown. METHODS: Patients presenting with ACS via ambulance (2014-2018) that underwent percutaneous coronary intervention (PCI) were prospectively collected via the Victorian Cardiac Outcomes Registry and Melbourne Interventional Group, linked to the Ambulance Victoria database. The primary outcome was 30-day major adverse cardiac events (MACE). Secondary outcomes were descriptive analyses of prehospital pain score, intravenous morphine equivalent analgesic dosing, plus predictors of MACE and thrombolysis in myocardial infarction (TIMI) 0-1 flow pre-PCI. RESULTS: A total of 10,547 patients were included (female: 2775 [26%]). Opioids were administered to 1585 (57%) females, 5068 (65%) males (p < 0.001). Adjusted 30-day MACE was similar between opioid groups in both sexes (female: odds ratio [OR]: 1.21, confidence interval [CI] 0.82-1.79, p = 0.34; male: OR: 0.89, CI: 0.68-1.16, p = 0.40). Median pain score at presentation was 6 (interquartile range [IQR]: 4, 8) for both sexes. Median opioid dose was 2.5 mg (IQR: 0, 10) in females and 5 mg (IQR: 0, 10) in males (p < 0.001), with similar pain relief achieved. Adjusted rates of TIMI 0-1 pre-PCI were higher in patients administered opioids (female: OR 2.9, CI: 2.07-4.07, p < 0.001; male: OR: 2.67, CI: 2.19-3.25, p < 0.001). CONCLUSIONS: Female patients undergoing PCI received less opioid analgesia, but no sex differences in prehospital pain scores were seen. Opioid administration was associated with impaired antegrade flow in the culprit artery in both sexes, but not short-term MACE. Trials evaluating nonopioid analgesics in ACS are needed.

The influence of ambulance offload time on 30-day risks of death and re-presentation for patients with chest pain.

OBJECTIVE: To assess whether ambulance offload time influences the risks of death or ambulance re-attendance within 30 days of initial emergency department (ED) presentations by adults with non-traumatic chest pain. DESIGN, SETTING: Population-based observational cohort study of consecutive presentations by adults with non-traumatic chest pain transported by ambulance to Victorian EDs, 1 January 2015 - 30 June 2019. PARTICIPANTS: Adults (18 years or older) with non-traumatic chest pain, excluding patients with ST elevation myocardial infarction (pre-hospital electrocardiography) and those who were transferred between hospitals or not transported to hospital (eg, cardiac arrest or death prior to transport). MAIN OUTCOME MEASURES: Primary outcome: 30-day all-cause mortality (Victorian Death Index data). SECONDARY OUTCOME: Transport by ambulance with chest pain to ED within 30 days of initial ED presentation. RESULTS: We included 213 544 people with chest pain transported by ambulance to EDs (mean age, 62 [SD, 18] years; 109 027 women [51%]). The median offload time increased from 21 (IQR, 15-30) minutes in 2015 to 24 (IQR, 17-37) minutes during the first half of 2019. Three offload time tertiles were defined to include approximately equal patient numbers: tertile 1 (0-17 minutes), tertile 2 (18-28 minutes), and tertile 3 (more than 28 minutes). In multivariable models, 30-day risk of death was greater for patients in tertile 3 than those in tertile 1 (adjusted rates, 1.57% v 1.29%; adjusted risk difference, 0.28 [95% CI, 0.16-0.42] percentage points), as was that of a second ambulance attendance with chest pain (adjusted rates, 9.03% v 8.15%; adjusted risk difference, 0.87 [95% CI, 0.57-1.18] percentage points). CONCLUSIONS: Longer ambulance offload times are associated with greater 30-day risks of death and ambulance re-attendance for people presenting to EDs with chest pain. Improving the speed of ambulance-to-ED transfers is urgently required.

Comparison of Out-of-Hospital Cardiac Arrests Occurring in Schools and Other Public Locations: A 12-Year Retrospective Study.

Objective: Out-of-hospital cardiac arrests (OHCA) in schools and universities are uncommon. However, these institutions must plan and prepare for such events to ensure the best outcomes. To evaluate their preparedness we assessed baseline characteristics, survival outcomes and 12-year trends for OHCA in schools/universities compared to other public locations.Methods: We conducted a retrospective analysis of OHCA in schools/universities and public locations between 2008 and 2019 using Victorian Ambulance Cardiac Arrest Registry data.Results: We included 9,037 EMS attended cases, 131 occurred in schools/universities and 8,906 in public locations. Compared to public locations, a significantly higher proportion of EMS treated cases in schools/universities received bystander cardiopulmonary resuscitation (CPR) (95.5% vs. 78.5%, p < 0.001), public access defibrillation (PAD) (26.1% vs. 9.9%, p < 0.001) and presented in shockable rhythms (69.4% vs. 50.9%, p < 0.001). Unadjusted survival to hospital discharge rates were also significantly higher in schools/universities (39.6% vs. 24.2%, p < 0.001). The long-term unadjusted trends for bystander CPR in schools/universities increased from 91.7% (2008-10) to 100% (2017-19) (p-trend = 0.025), for PAD from 4.2% (2008-10) to 47.5% (2017-19) (p-trend < 0.001) and for survival to hospital discharge from 16.7% (2008-10) to 57.5% (2017-19) (p-trend = 0.004). However, after adjustment for favorable cardiac arrest factors, such as younger age, bystander CPR and PAD, survival was similar between schools/universities and public locations.Conclusion: The majority of OHCA in schools and universities were witnessed and received bystander CPR, however less than half received PAD. Developing site-specific cardiac emergency response plans and providing age appropriate CPR training to primary, secondary and university students would help improve PAD rates.

Effects of lignocaine vs. opioids on antiplatelet activity of ticagrelor: the LOCAL trial.

AIMS: We assessed the impact of intravenous fentanyl and lignocaine on the pharmacokinetics and pharmacodynamics of ticagrelor in patients with unstable angina and non-ST-elevation myocardial infarction and their procedural analgesic efficacy and safety. METHODS AND RESULTS: Seventy patients undergoing coronary angiography with ticagrelor loading were included in the pharmacokinetic and pharmacodynamic analyses of this randomized trial. Plasma ticagrelor levels 2 h post-loading dose were significantly lower in the fentanyl arm than in the lignocaine treatment arm (598 vs. 1008 ng/mL, P = 0.014). The area under the plasma-time curves for ticagrelor (1228 vs. 2753 ng h/mL, P < 0.001) and its active metabolite (201 vs. 447 ng h/mL, P = 0.001) were both significantly lower in the fentanyl arm. Expression of activated platelet glycoprotein IIb/IIIa receptor (2829 vs. 1426 mean fluorescence intensity, P = 0.006) and P-selectin (439 vs. 211 mean fluorescence intensity, P = 0.001) was significantly higher at 60 min in the fentanyl arm. A higher proportion of patients had high on-treatment platelet reactivity in the fentanyl arm at 60 min using the Multiplate Analyzer (41% vs. 9%, P = 0.002) and 120 min using the VerifyNow (30% vs. 3%, P = 0.003) and VASP (37% vs. 6%, P = 0.002) assays. Both drugs were well tolerated with a high level of patient satisfaction. CONCLUSIONS: Unlike fentanyl, lignocaine does not impair the bioavailability or delay the antiplatelet effect of ticagrelor. Both drugs were well tolerated and effective with a high level of patient satisfaction for procedural analgesia. Routine procedural analgesia during percutaneous coronary intervention should be reconsidered and if performed, lignocaine is a beneficial alternative to fentanyl.

Predictors of hospital prenotification for STEMI and association of prenotification with outcomes.

BACKGROUND: Delay to reperfusion in ST-elevation myocardial infarction (STEMI) is detrimental, but can be minimised with prehospital notification by ambulance to the treating hospital. We aimed to assess whether prenotification was associated with improved first medical contact to balloon times (FMC-BT) and whether this resulted in better clinical outcomes. We also aimed to identify factors associated with use of prenotification. METHODS: This was a retrospective study of prospective Victorian Cardiac Outcomes Registry data for patients undergoing primary percutaneous coronary intervention for STEMI from 2013-2018. Postcardiac arrest were excluded. Patients were grouped by whether they arrived by ambulance with prenotification (group 1), arrived by ambulance without prenotification (group 2) or self-presented (group 3). We compared groups by FMC-BT, incidence of major adverse cardiac and cerebrovascular events (MACCE), mortality and factors associated with the use of prenotification. RESULTS: 2891 patients were in group 1 (79.3% male), 1620 in group 2 (75.7% male) and 1220 in group 3 (82.9% male). Patients who had prenotification were more likely to present in-hours (p=0.004) and self-presenters had lowest rates of cardiogenic shock (p<0.001). Prenotification had shorter FMC-BT than without prenotification (104 min vs 132 min, p<0.001) Self-presenters had superior clinical outcomes, with no difference between ambulance groups. Groups 1 and 2 had similar 30-day MACCE outcomes (7.4% group 1 vs 9.1% group 2, p=0.05) and similar mortality (4.6% group 1 vs 5.9% group 2, p=0.07). In multivariable analysis, male gender, right coronary artery culprit and in-hours presentation independently predicted use of prenotification (all p<0.05). CONCLUSION: Differences in clinical characteristics, particularly gender, time of presentation and culprit vessel may influence ambulance prenotification. Ambulance cohorts have high-risk features and worse outcomes compared with self-presenters. Improving system inequality in prehospital STEMI diagnosis is recommended for fastest STEMI treatment.

Cardiac arrests in general practice clinics or witnessed by emergency medical services: a 20-year retrospective study.

OBJECTIVE: To compare the frequency and outcomes of cardiac arrests in general practice clinics with those of paramedic-witnessed cardiac arrests. DESIGN, SETTING: Retrospective study; analysis of Victorian Ambulance Cardiac Arrest Registry data, 1 January 2000 - 30 December 2019. PARTICIPANTS: Patients with non-traumatic cardiac arrests whom emergency medical services staff attempted to resuscitate. MAIN OUTCOME MEASURES: Survival to hospital discharge. RESULTS: 6363 cases of cardiac arrest were identified: 216 in general practice clinics (3.4%) and 6147 witnessed by paramedics (96.6%). The proportion of patients presenting with initial shockable rhythms was larger in clinic (126 patients, 58.3%) than paramedic-witnessed cases (1929, 31.4%). The proportion of general practice clinic cases in which defibrillation was provided in the clinic increased from 2 of 37 in 2000-2003 (5%) to 19 of 57 patients in 2016-2019 (33%); survival increased from 7 of 37 (19%) to 23 of 57 patients (40%). For patients with initial shockable rhythms, 57 of 126 in clinic cases (45%) and 1221 of 1929 people in paramedic-witnessed cases (63.3%) survived to hospital discharge; of 47 general practice patients defibrillated by clinic staff, 27 survived (57%). For patients with initial shockable rhythms, the odds of survival were greater following paramedic-witnessed events (adjusted odds ratio [aOR], 3.39; 95% CI, 2.08-5.54) or general clinic arrests with defibrillation by clinic staff (aOR, 2.23; 95% CI, 1.03-4.83) than for general practice clinic arrests in which arriving paramedics provided defibrillation. CONCLUSION: Emergency medical services should be alerted as soon as possible after people experience heart attack warning symptoms. Automated external defibrillators should be standard equipment in general practice clinics, enabling prompt defibrillation, which may substantially reduce the risk of death for people in cardiac arrest.

The Impact of the COVID-19 Pandemic on Demand for Emergency Ambulances in Victoria, Australia.

Objective: Relatively little has been reported about the impact of COVID-19 restrictions on emergency ambulance services. We describe the influence of the COVID-19 pandemic on the emergency ambulance system in Victoria, Australia.Methods: We performed an interrupted time series analysis of consecutive calls for ambulance from January 2018 to February 2021, including two waves of COVID-19. The COVID-19 lockdown period included seven months of stay-at-home restrictions (16/03/2020-18/10/2020). Nineteen weeks of post-lockdown data were included (19/10/2020-28/02/2021).Results: In total, 2,356,326 consecutive calls were included. COVID-19 lockdown was associated with an absolute reduction of 64,991 calls (almost 2,100 calls/week). According to time series analysis, lockdown was associated with a 12.6% reduction in weekly calls (IRR = 0.874 [95% CI 0.811, 0.941]), however no change in long-term trend (IRR = 1.000 [95% CI 0.996, 1.003]). During lockdown, the long-term trend of attendances to patients with suspected acute coronary syndromes (ACS, IRR = 1.006 [95% CI 1.004, 1.009]) and mental health-related issues (IRR = 1.005 [95% CI 1.002, 1.008]) increased. After lockdown, the call volume was 5.6% below pre-COVID-19 predictions (IRR = 0.944 [95% CI 0.909, 0.980]), however attendances for suspected ACS were higher than predicted (IRR = 1.069 [95% CI 1.009, 1.132]). Ambulance response times deteriorated, and total case times were longer than prior to the pandemic, driven predominantly by extended hospital transfer times.Conclusion: The COVID-19 pandemic had a dramatic impact on the emergency ambulance system. Despite lower call volumes post-lockdown than predicted, we observed deteriorating ambulance response times, extended case times and hospital delays. The pattern of attendance to patients with suspected ACS potentially highlights the collateral burden of delaying treatment for urgent conditions.

Drivers of Increasing Emergency Ambulance Demand.

Objectives: Although the factors driving emergency department demand have been extensively investigated, a comparatively minimal amount is known about the factors that are driving an increase in emergency ambulance demand. Methods: We conducted a retrospective observational study of consecutive cases attended by Ambulance Victoria in Melbourne, Australia from 2008 to 2015. Incidence rates were calculated, and adjusted time series regression analyses were performed to assess the driving factors of ambulance demand. Results: A total of 2,443,952 consecutive cases were included. Demand grew by 29.2% over the 8-year period. The age-specific incidence increased significantly over time for patients aged < 60 years, but not for patients aged ≥ 60 years. After adjustment for seasonality and population growth, demand increased by 1.4% per annum (incident rate ratio [IRR] = 1.014 [1.011-1.017]). The largest annual growth in demand was observed in patients with a history of mental health issues (IRR = 1.058 [1.054-1.062]), alcohol/drug abuse (IRR = 1.061 [1.056-1.066]), or a Charlson Comorbidity Index [CCI] score ≥ 4 (IRR = 1.045 [1.039-1.051]). Cases involving patients of relative socio-economic/educational disadvantage, younger age, or with no preexisting health conditions according to the CCI also grew faster than the overall patient population. Cases requiring transport to hospital increased by 1.2% annually (IRR = 1.012 [1.009-1.016]), although patients not requiring medical intervention from paramedics increased by 6.7% annually (IRR = 1.067 [1.063-1.072]). Conclusions: Increases in ambulance demand exceeded population growth. Emergency ambulances were increasingly utilized for transport of patients who did not require medical intervention from paramedics. Identifying the characteristics of patients driving ambulance demand will enable targeted demand management strategies.

Temporal Trends in the Incidence, Characteristics, and Outcomes of Hanging-Related Out-of-Hospital Cardiac Arrest.

Aim: The aim of this study was to describe temporal trends in the incidence, characteristics, and outcomes of hanging-related out-of-hospital cardiac arrest (OHCA). Method: A retrospective study of all hanging-related OHCA in Victoria, Australia, between 2000 and 2017 was conducted. Trends in incidence, characteristics, and outcomes were assessed using linear regression and a non-parametric test for trend, as appropriate. Predictors of survival to hospital discharge were identified using multivariable logistic regression. Results: Between 2000 and 2017, emergency medical services (EMS)-attended 3,891 cases of hanging-related OHCA, of which 876 cases (23%) received an attempted resuscitation. The overall incidence rate of EMS-attended cases was 3.8 cases per 100,000 person-years increasing from 2.3 cases per 100,000 person-years in 2000 to 4.7 cases in 2017 (p for trend <0.001). Incidence rates increased approximately two-fold in young adults (18-44 years) and three-fold in middle aged adults (45-64 years). Despite improvement in the rate of bystander cardiopulmonary resuscitation (from 49% in 2000-2005 to 75% in 2012-2017), the survival to hospital discharge rate remained unchanged (3% overall). Among adult survivors with 12-month follow-up (n = 10), five patients responded to telephone interviews. Of those, three (60%) reported severe functional disability. Five patients responded to telephone interviews, of which 3 patients reported severe functional disability. An initial shockable rhythm (OR 23.17, 95% CI: 5.75, 93.36) or pulseless electrical activity (OR 13.14, 95% CI: 4.79, 36.03) were associated with survival. Conclusion: The incidence of hanging-related OHCA doubled over the 18 year period with no change to survival rates. New preventative strategies are needed to reduce the community burden of these events.