Evaluating a prehospital model of care involving risk assessment, point-of-care troponin, and virtual emergency department to accelerate the provision of definitive care for chest pain

When a patient attended by Ambulance Victoria for chest pain meets all inclusion criteria and no exclusion criteria, additional components will determine which clinical pathway a patient will take: 1. Risk score calculation embedded within the Ambulance Victoria Clinical Practice Guideline (CPG) mobile phone app. - Risk assessment will involve calculation of the Early Chest pain Admission, myocardial infarction (MI), and Mortality (ECAMM) risk score that was developed and validated by the Investigators and determines the risk of cardiac and non-cardiac causes of chest pain. It will take approximately 5 minutes to complete the risk assessment. - The ECAMM risk score is a measure of early all-inclusive risk, predicting the risk of hospital admission for any diagnosis (other than non-specific pain), 30-day MI, and 30-day all-cause mortality among patients with undifferentiated chest pain. It provides a numerical risk assessment not limited to coronary diagnoses alone. - The score categorises patients into low, intermediate, or high risk according to cut-off scores. - The score calculator will be embedded within the current CPG mobile app on phones carried by all paramedics as part of the chest pain CPG. **If the patient is deemed to be intermediate risk or high risk via the ECAMM score, patients will be transported to hospital as is the current standard of care. 2. Prehospital point-of-care (POC) high-sensitivity troponin testing performed by paramedics. - Measurement of high-sensitivity troponin at the point of patient care will determine the next steps in the new pathway of care. - Paramedics will collect capillary blood via finger prick for testing and apply a sample to the test cartridge that is then inserted into the POC device for measurement. It will take 1-2 minutes to collect the blood and insert the cartridge into the device for troponin measurement. The device takes 8 minutes to analyse the sample and return the troponin result. - The POC device to be used is Australian Government Therapeutic Goods Administration approved. - Real-time results will be provided in 8 minutes and will be the same quality as laboratory results. **If the POC troponin test is positive, the patient will no longer be considered at low risk, and will be transported by ambulance to the nearest hospital for further investigation and care. **Only when the risk score defines the patient as being at low risk AND the troponin test is negative, will the VVED be considered for use by paramedics. 3. Victorian Virtual Emergency Department (VVED) consultation If a patient meets the criteria for low risk via the ECAMM Score and the POC troponin test is negative, paramedics will call VVED to arrange a consultation (available 24 hours per day, 7 days per week) which will be conducted whilst paramedics are still on scene and with the patient, as per usual Ambulance Victoria processes. A VVED clinician will provide a telehealth consultation (approximately 15 minutes in length) and confirm that the patient is suitable for outpatient follow-up and provide referrals where appropriate. If the VVED clinician feels the patient is not fit for prehospital discharge and still requires ED assessment, paramedics will transport them to the nearest hospital. Patients will also be able to request transport to ED at any time prior to paramedic departure. Paramedic training: As with the introduction of all new Ambulance Victoria CPGs, training will be provided to all paramedics in the form of an online learning package that will include demonstration videos. Training paramedics to use the POC device will occur via a train the trainer model with the device company providing face-to-face training to a group of paramedics who will then provide face-to-face training to the remining paramedic workforce. Monitoring of intervention adherence and fidelity: Adherence to the new CPG and fidelity of the intervention will be monitored by reviewing the patient care records for all patients who are treated by paramedics according to the new CPG and patients who meet the eligibility criteria but for whom the intervention was not provided (including following up the reasons why the intervention wasn't provided).