Prehospital Use of Aspirin Rarely Is Associated with Adverse Events

Machine learning predicts emergency physician specialties from treatment strategies for patients suspected of myocardial infarction

BACKGROUND

Our investigation aimed to determine how the diverse backgrounds and medical specialties of emergency physicians (Eps) influence the accuracy of diagnoses and the subsequent treatment pathways for patients presenting preclinically with MI symptoms. By scrutinizing the relationships between EPs' specialties and their approaches to patient care, we aimed to unveil potential variances in diagnostic accuracy and treatment choices.

METHODS

In this retrospective, monocenter cohort study, we leveraged machine learning techniques to analyze a comprehensive dataset of 2328 patients with suspected MI, encompassing preclinical diagnoses, electrocardiogram (ECG) interpretations, and subsequent treatment strategies by attending EPs.

RESULTS

We demonstrated that diagnosis and treatment patterns of different specialties were distinct enough, that machine learning (ML) was able to differentiate between specialties (maximum area under the receiver operating characteristic = 0.80 for general medicine and 0.80 for surgery). In our study, internist demonstrated the highest accuracy for preclinical identification of STEMI (0.96) whereas surgeons showed the highest accuracy for identifying NSTEMI. Our findings highlight significant correlations between EP specialties and the accuracy of both preclinical diagnoses and subsequent treatment pathways for patients with suspected MI.

CONCLUSIONS

Our results offer valuable insights into how the diverse backgrounds and specialties of EPs can influence the optimization of patient care in emergency settings. Understanding these patterns can help in the development of tailored training programs and protocols to enhance diagnostic accuracy and treatment efficacy in emergency cardiac care, ultimately optimizing patient treatment and improving outcomes.

Pretransfer Aspirin Administration and Its Impact on Angiographic Outcomes for Patients with ST-Elevation Myocardial Infarction

Although guidelines recommend early aspirin administration after diagnosis of ST-elevation myocardial infarction (STEMI), the decision of pretransfer aspirin administration is at the discretion of the primary physicians. Therefore, this study aimed to determine whether pretransfer aspirin administration was associated with better angiographical outcomes in patients with STEMI. This study compared the angiographic findings of thrombolysis in myocardial infarction (TIMI) flow grade in the infarct-related artery before percutaneous coronary intervention (PCI) between patients who received pretransfer aspirin and those who did not. In total, 28 patients (11.2%) were administered aspirin before transfer and 219 (88.8%) were administered aspirin upon arrival at the hospital. Propensity score matching yielded 135 patients [27 patients (20%) who were administered aspirin before transfer and 108 patients (80%) who were administered aspirin upon arrival at the hospital]. Patients who received pretransfer aspirin had a higher rate of TIMI-3 flow before PCI compared to those who did not receive pretransfer aspirin [8 (28.6%) versus 15 (6.8%), P < 0.01, in all study patients; 8 (26.6%) versus 7 (6.5%), P < 0.01, in propensity-score-matched patients]. Multivariable logistic regression analysis revealed that pretransfer aspirin administration was significantly associated with the presence of TIMI-3 flow before PCI, independent of age, gender, transfer time, and statin use (OR: 5.43, 95% CI: 1.94-15.2, P < 0.01, in all study patients; OR: 6.17, 95% CI: 1.86-20.46, P < 0.01, in propensity-score-matched patients). Pretransfer aspirin administration could lead to the early restoration of coronary blood flow in patients with STEMI, supporting its active use in STEMI care.

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.

Prehospital Administration of Aspirin and Nitroglycerin for Patients With Suspected Acute Coronary Syndrome ― A Systematic Review ―

Background: Recent guidelines for acute coronary syndrome (ACS) recommend prehospital administration of aspirin and nitroglycerin for ACS patients. However, there is no clear evidence to support this. We investigated the benefits and harms of prehospital administration of aspirin and nitroglycerin by non-physician healthcare professionals in patients with suspected ACS.

Methods and Results: We searched the PubMed database and used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence. Three retrospective studies for aspirin and 1 for nitroglycerin administered in the prehospital setting to patients with acute myocardial infarction were included. Prehospital aspirin administration was associated with significantly lower 30-day and 1-year mortality compared with aspirin administration after arrival at hospital, with odds ratios (OR) of 0.59 (95% confidence interval [CI] 0.35–0.99) and 0.47 (95% CI 0.36–0.62), respectively. Prehospital nitroglycerin administration was also associated with significantly lower 30-day and 1-year mortality compared with no prehospital administration (OR 0.34 [95% CI 0.24–0.50] and 0.38 [95% CI 0.29–0.50], respectively). The certainty of evidence was very low in both systematic reviews.

Conclusions: Our systematic reviews suggest that prehospital administration of aspirin and nitroglycerin by non-physician healthcare professionals is beneficial for patients with suspected ACS, although the certainty of evidence is very low. Further investigation is needed to determine the benefit of the prehospital administration of these agents.

Ambulance nurses' experiences of using prehospital guidelines for patients with acute chest pain - A qualitative study

BACKGROUND

Ambulance nurses have an important role in early recognition and treatment often being the first medical contact for patients with acute chest pain. However, there is sparse knowledge on the experiences of ambulance nurses with regard to use of Prehospital Guidelines for patients with Acute Chest Pain.

AIM

To explore ambulance nurses' experiences of using prehospital guidelines for patients with acute coronary syndrome.

METHOD

A qualitative descriptive study design. Semi-structured interviews with 22 ambulance nurses recruited through purposive sampling strategy. The material was transcribed and analysed using content analysis.

RESULTS

Two main categories emerged from the results. The first category Sense of professional obligation included experiences of having an important role in caring for patients with acute chest pain. Understanding this role and the collaboration in the chain of care prompted ambulance nurses to adhere to the guidelines. However, not receiving enough feedback on the provided care made them uncertain whether to use guidelines. The second category Clinical difficulties using guidelines consisted of experiences of being surrounded by practical challenges while using guidelines. Ambulance nurses meet these challenges by relying on their clinical experience, which sometimes led to them deviating from the guidelines.

CONCLUSIONS

The ambulance nurses experienced a mixture of feeling secure and insecure when using the guidelines. Foremost, when encountering patients with unspecific chest pain, they felt a lack of feedback and an insufficient collaboration within the chain of care, which made them deviate from guidelines. To increase adherence in guidelines, post-registration education to update the knowledge and skills about guidelines for acute chest pain is needed followed by formal inter-disciplinary feedback on the care provided.

Guideline adherence among prehospital emergency nurses when caring for patients with chest pain: a prospective cohort study

Background

The emergency medical services (EMS) use guidelines to describe optimal patient care for a wide range of clinical conditions and symptoms. The intent is to guide personnel to provide patient care in line with best practice. The aim of this study is to describe adherence to such guidelines among prehospital emergency nurses (PENs) when caring for patients with chest pain.

Objective

To describe guideline adherence among PENs when caring for patients with chest pain. To investigate whether guideline adherence is associated with patient age, sex or final diagnosis of acute myocardial infarction on hospital discharge.

Methods

Guideline adherence in terms of patient examination and pharmaceutical treatment was analysed in a cohort of 2092 EMS missions carried out in 2018 in Region Halland, Sweden. Multivariate regression was used to describe how guideline adherence is associated with patient age, sex and diagnosis on hospital discharge.

Results

Guideline adherence was high regarding examination of vital signs (93%) and electrocardiogram (ECG) registration (96%) but lower in terms of pharmaceutical treatment (ranging from 28 to 90%). Adherence was increased in cases in which the patient ended up with acute myocardial infarction (AMI) as diagnosis on discharge. Patients with AMI were given acetylsalicylic acid by PENs in 50% of cases. Women were less likely than men to receive treatment with acetylsalicylic acid and oxycodone.

Conclusions

Guideline adherence among PENs when caring for patients with chest pain is satisfactory in terms vital signs and ECG registration. Regarding pharmaceutical treatment guideline adherence is defective. Improved adherence is mainly associated with male sex in patients and a diagnosis of AMI on hospital discharge. Defective adherence excludes measures known to improve patients’ prognoses such as treatment with acetylsalicylic acid.

European Resuscitation Council Guidelines 2021: First aid

The European Resuscitation Council has produced these first aid guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics include the first aid management of emergency medicine and trauma. For medical emergencies the following content is covered: recovery position, optimal positioning for shock, bronchodilator administration for asthma, recognition of stroke, early aspirin for chest pain, second dose of adrenaline for anaphylaxis, management of hypoglycaemia, oral rehydration solutions for treating exertion-related dehydration, management of heat stroke by cooling, supplemental oxygen in acute stroke, and presyncope. For trauma related emergencies the following topics are covered: control of life-threatening bleeding, management of open chest wounds, cervical spine motion restriction and stabilisation, recognition of concussion, cooling of thermal burns, dental avulsion, compression wrap for closed extremity joint injuries, straightening an angulated fracture, and eye injury from chemical exposure.

Early or First Aid Administration Versus Late or In-hospital Administration of Aspirin for Non-traumatic Adult Chest Pain: A Systematic Review

Chest pain is a common symptom of acute coronary syndrome, including myocardial infarction (MI). Treatment with antiplatelet agents, such as aspirin, improves survival, although the ideal dose is uncertain. It is unknown if outcomes can be improved by giving aspirin early in the course of MI as part of the first-aid management as opposed to late or in-hospital administration. We searched the Medline, Embase, and Cochrane databases and used Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) and Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) for determining the certainty of evidence. We included studies in adults with non-traumatic chest pain, where aspirin was administered early (within two hours) following the onset of chest pain as part of first-aid management as compared with late or in-hospital administration (The International Prospective Register of Systematic Reviews (PROSPERO) registration number: CDR153316). From 1470 references, we included three studies (one randomized controlled trial (RCT) and two non-RCTs). Early administration (median 1.6 hours or pre-hospital) was associated with increased survival as compared with late administration (median 3.5 hours or in-hospital) at seven days; risk ratio (RR) 1.04 (95% CI 1.03-1.06), 30 days RR 1.05 (95% 1.02-1.07), and one-year RR 1.06 (95% CI1.03-1.10). The evidence is of very low certainty due to limitations in study design and the imprecision of the evidence. This systematic review would suggest that the early or first-aid administration of aspirin to adults with non-traumatic chest pain improves survival as compared with late or in-hospital administration.

Determinants of pre-hospital pharmacological intervention and its association with outcome in acute myocardial infarction

BACKGROUND

The aim of this study was a) To identify predictors of the use of aspirin in the pre-hospital setting in acute myocardial infarction (AMI) and b) To analyze whether the use of any of the recommended medications was associated with outcome.

METHODS

All patients with a final diagnosis of AMI, transported by the Emergency Medical Services (EMS) and admitted to the coronary care unit at Sahlgrenska University Hospital in Gothenburg, Sweden, in 2009-2011, were included.

RESULTS

1,726 patients were included. 58 % received aspirin by the EMS. Ischemic heart disease (IHD) was suspected in 84 %. Among patients who did not receive aspirin IHD was still suspected in 67 %. Among patients in whom IHD was suspected, and who were not on chronic treatment with aspirin the following predicted its pre-hospital use: a) age (odds ratio 0.98; 95 % confidence interval (CI) 0.96-0.99); b) a history of myocardial infarction (2.21; 1.21-4.04); c) priority given by EMS (8.07; 5.42-12.02); d) ST-elevation on ECG on admission to hospital (2.22; 1.50-3.29); e) oxygen saturation > 90 % (3.37; 1.81-6.27). After adjusting for confounders among patients who were not on chronic aspirin, only nitroglycerin of the recommended medications was associated with a reduced risk of death within 1 year (hazard ratio 0.40; 95 % CI 0.23-0.70).

CONCLUSIONS

Less than six out of ten patients with AMI received pre-hospital aspirin. Five clinical factors were independently associated with the pre-hospital administration of aspirin. This suggests that the decision to treat is multifactorial, and it highlights the lack of accurate diagnostic tools in the pre-hospital environment. Nitroglycerin was independently associated with a reduced risk of death, suggesting that we select the use for a low-risk cohort.

Observation Units as Substitutes for Hospitalization or Home Discharge

STUDY OBJECTIVE

Observation unit admissions have been increasing, a trend that will likely continue because of recent changes in reimbursement policies. The purpose of this study is to determine the effect of the availability of observation units on hospitalizations and discharges to home for emergency department (ED) patients.

METHODS

We studied ED visits with a final diagnosis of chest pain in the National Hospital Ambulatory Medical Care Survey from 2007 to 2010. ED visits that resulted in an observation unit admission were propensity-score matched to visits at hospitals without an observation unit. We used logistic regression to develop a prediction model for hospitalization versus discharge home for matched patients treated at nonobservation hospitals. The model was applied to matched observation unit patients to determine the likely alternative disposition had the observation unit not been available.

RESULTS

There were 1,325 eligible visits that represented 5,079,154 visits in the United States. Two hundred twenty-seven visits resulted in an observation unit admission. The predictive model for hospitalization had a c statistic of 0.91; variables significantly associated with subsequent hospitalization included age, history of coronary atherosclerosis, systolic blood pressure less than 115 beats/min, and administration of antianginal medications. When the model was applied to matched observation unit patients, 49.9% of them were categorized as discharge home likely.

CONCLUSION

In this study, we estimated that half of ED visits for chest pain that resulted in an observation unit admission were made by patients who may have been discharged home had the observation unit not been available. Increased availability of observation units may result in both decreased hospitalizations and decreased discharges to home.

Dyspnea and reversibility of antiplatelet agents: ticagrelor, elinogrel, cangrelor, and beyond

CONTEXT

Oral reversible platelet P2Y12 receptor inhibitors (ticagrelor and elinogrel) cause double-digit rates of dyspnea, while irreversible oral antiplatelet drugs (aspirin, ticlopidoine, clopidogrel, and prasugrel) or intravenous glycoprotein IIb/IIIa inhibitors (abciximab, eptifibatide, or tirofiban) do not increase the incidence of dyspnea in randomized trials. Dyspnea after oral reversible antiplatelet agents remains unexplained. A transfusion-related acute lung injury (TRALI) hypothesis has been proposed. The dyspnea risks after cangrelor, an intravenous reversible antiplatelet agent, are not well defined but may offer a universal mechanism linking TRALI, dyspnea, and reversible platelet inhibition.

OBJECTIVE

We analyzed safety data from recent head-to-head randomized trials with reversible antiplatelet agents (ticagrelor, elinogrel, and cangrelor) compared to irreversible (clopidogrel/placebo) comparators.

RESULTS

All three reversible antiplatelet agents cause excess dyspnea. In contrast to the high double-digit rates after oral ticagrelor or elinogrel, the dyspnea risks after intravenous cangrelor were smaller (<2%) but still consistently and significantly higher than in the corresponding control arms.

CONCLUSIONS

The clinical utility of reversible antiplatelet strategies has been challenged. Despite a potential advantage of fewer bleeding events during heart surgery, reversible antiplatelet agents carry the risk of potential autoimmune reactions manifesting as dyspnea. Repeated binding and unbinding cycles, impaired platelet turnover, and lung sequestration or apoptosis of overloaded destructive platelets are among the potential mechanism(s) responsible for dyspnea after reversible antiplatelet agents.

Dyspnoea after antiplatelet agents: the AZD6140 controversy

Recent randomised studies suggest that experimental oral reversible platelet P2Y12 receptor inhibitor, AZD6140, causes dyspnoea. This also raises similar concerns about the parent compound, and another adenosine triphosphate (ATP) analogue (AR-69931MX or cangrelor), which is currently in Phase 3 trial in patients undergoing coronary interventions. We analysed package inserts, and available clinical trials safety data for antiplatelet agents with regard to the incidence of dyspnoea. We found that dyspnoea is a very rare complication of the presently approved platelet inhibitors, mostly caused by underlying disease, rather than antiplatelet therapy per se. The main reasons for respiratory distress after oral (AZD6140), and intravenous (cangrelor) agents may be the development of mild asymptomatic thrombotic thrombocytopenic purpura, fluid retention and dyspnoea because of the reversible nature of these drugs. Also, these agents are ATP analogues, which rapidly metabolise to adenosine, a well-known bronchoprovocator causing dyspnoea as well. In summary, dyspnoea is seldom considered, there are no treatment algorithms when it does occur, plausible mechanisms exist and despite these plausible mechanisms, the true cause of dyspnoea in these exposed individuals is unknown. Additional pulmonary function testing, immunological investigations and platelet receptor studies are urgently needed to determine the cause of dyspnoea after AZD6140, and to point out how such serious adverse reactions can be prevented, or at least minimised, raising potential concerns about this drug.

Reasons prehospital personnel do not administer aspirin to all patients complaining of chest pain

INTRODUCTION

Aspirin is administered to patients with acute coronary syndromes (ACSs), but prehospital providers do not administer aspirin to all patients with chest pain that could be secondary to an ACS.

OBJECTIVE

To identify reasons prehospital providers fail to administer aspirin to all patients complaining of chest pain.

METHODS

A convenience sample of prehospital providers was surveyed as they transported patients with a chief complaint of chest pain to the emergency department. The providers were asked if they had given aspirin, nitroglycerin, or oxygen, or if they utilized a monitor. If the medications had not been administered, the paramedic was asked about the reason. The patient's age and previous cardiac history also was recorded.

RESULTS

A total of 52 patients with chest pain who were transported were identified over eight weeks, and all of the providers agreed to participate in the study. Only 13 of the patients (25%) received aspirin. Reasons given for not administering aspirin to the other 39 patients included: (1) chest pain was not felt to be cardiac in 13 patients (33%); (2) 10 patients already had taken aspirin that day (26%); (3) the medical provider was a basic-level emergency medical technician (EMT)-Basic and could not administer aspirin to six patients (15%); (4) pain subsided prior to arrival of emergency medical services (EMS) in these three patients; and (5) other reasons were provided for the remaining seven patients.

CONCLUSIONS

The most common reason that paramedics did not administer aspirin was the paramedic's belief that the chest pain was not of a cardiac nature. Another common reason for not giving aspirin was the inability of EMT-Basic providers to administer aspirin.