Pre-hospital ECG in Acute Coronary Syndromes
Condition: Acute Coronary Syndrome; STEMI; Non STEMI
MeSH terms: Acute Coronary Syndrome; Syndrome
Study type: Observational

Summary: 
      The Pre-Hospital 12-lead electrocardiogram (PHECG) is a simple test that helps ambulance
      clinicians assess patients with suspected acute coronary syndrome (heart attack), and
      provides clinical data to inform ongoing care. This project builds on previous work by this
      team, which found that one in three eligible patients did not receive a PHECG, but those that
      did had a lowered risk of short-term death. In this study the investigators will update that
      work, and explore reasons for variations in practice - highlighting opportunities to improve
      care and outcomes.

      Using routinely collected data and qualitative methods, the investigators will research
      patient, practitioner and contextual factors contributing to the decision to administer a
      PHECG. The aim is also to develop an intervention to increase the proportion of eligible
      patients that receive a PHECG, and to produce a proposal for further funding to test this
      intervention in a subsequent randomised trial.
    

Detailed description: 
      This mixed methods design study consists of four work packages:

      WP1 - Population-based, linked cohort study using MINAP data from 2010-2016

      This work package will entail analysis of data from around 420,000 pseudonymised patient
      records from the MINAP database, linking to the Office for National Statistics (ONS) in order
      to determine mortality/vital status. No patients will be contacted to obtain consent for
      inclusion of their records in the study as NICOR (custodian of MINAP data) hold section 251
      exemption to hold and process patient data for clinical audit purposes without their explicit
      consent. The data will be released to the research team, using established processes, in
      pseudonymised format.

      The study statisticians will analyse the data provided from MINAP to determine how many heart
      attack patients who came by ambulance survive to 30 days, estimate time to death, and will
      estimate from the data whether more people who had an ambulance ECG survive compared to those
      who did not have the test.

      The aim of the study is also to determine from the data whether patients who have an
      ambulance ECG receive treatment in hospital faster than those who did not.

      WP2 - Retrospective chart review of ambulance records

      The study statisticians will generate from the larger sample discussed above, a smaller
      sample (approximately 1800 patients in total) specific to three National Health Service (NHS)
      ambulance services (Welsh, West Midlands and South West). The investigators will then work
      with those ambulance services to review the records held by the ambulance service, to see
      what other information over and above that is collected in the national MINAP audit (e.g.
      presenting symptoms, severity of any chest pain, public place or home, patient preferences
      including declining to have the test, ambulance clinician grade and gender). The
      investigators have worked with a 'task and finish group' of paramedics and cardiology experts
      to agree which data might be helpful and devised specific forms to collect these data. Data
      collection from ambulance records will be undertaken by NHS paramedics in the three ambulance
      services, seconded to work on this project. These paramedics will receive specific training
      in study procedures to ensure accuracy and data quality. Anonymised data collected by these
      'research paramedics' will be sent to the research team by secure electronic database.

      WP3 - Ambulance clinician self-report on PHECG recording

      In this work package, clinical staff from the three participating ambulance Trusts (48 in
      total) will be invited to participate in focus group discussions led by an experienced
      researcher. A semi-structured topic guide (developed beforehand with the help and advice of a
      small group of paramedics and cardiac experts, and our knowledge of previous literature on
      paramedic decision making) will be used to explore the view of consenting ambulance
      clinicians about their perceptions of the role of the PHECG, their experiences of assessing
      patients with suspected heart attack, and factors which might influence the decision to
      record (or not) an ECG when assessing and treating a patient.

      Focus group discussions will be audio-recorded and transcribed. A method called framework
      analysis will be used to analyse the transcribed records of the focus group discussions to
      see whether any particular themes arise, including consensus or disagreement of ambulance
      staff views on recording an ECG, and consider them against any differences in the
      characteristics of focus group participants (e.g. grade of clinician, employing ambulance
      service's local practice).

      WP4 - Synthesis of the findings

      The investigators will bring together ambulance staff, patient representatives, cardiac
      experts and researchers to consider the findings from the three work packages described
      above, with aim to synthesise the study findings and present evidence addressing the study
      research questions. This will be done with consideration of the investigators' work as
      forming the 'development phase' for the design of a complex intervention for further testing
      in a later study.

      The project has been designed with input from patient and public representatives especially
      around the importance of the research question(s), potential impact of the findings for
      patients and the public. The study team includes three paramedics who have been instrumental
      in the design of the study as well as supporting documentation particularly for WP3.
    

Intervention name(s): No interventions
Intervention type(s): Other
Intervention description(s): No interventions
Observational model: Other
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Two types of study populations:

          1. - Patients with confirmed diagnosis of ACS in MINAP database as per inclusion and
             exclusion criteria

          2. - Emergency Medical Service personnel who have been trained to perform 12 lead ECG.
      
Keywords: Acute coronary syndrome; Emergency Medical Services; Electrocardiogram; Outcomes