The development of a decision support tool in the prehospital setting for acute chest pain - a study protocol for an observational study (BRIAN2).

Introduction: Chest pain is one of the most common reasons for contacting the emergency medical services (EMS). It is difficult for EMS personnel to distinguish between patients suffering from a high-risk condition in need of prompt hospital care and patients suitable for non-conveyance. A vast majority of patients with chest pain are therefore transported to the emergency department (ED) for further investigation even if hospital care is not necessary. Improved prehospital assessment and risk stratification, thus accurately and safely identifying patients suitable for non-conveyance, could prevent unnecessary transport to the ED. This would reduce ED crowding and overburdening sparse EMS resources. It would thus also probably reduce healthcare costs. Little is known about the prehospital use of the 5th generation, i.e. high-sensitivity troponin analyses. The aim of this project is to develop an EMS decision support tool using high-sensitivity troponin I for risk assessment of chest pain patients.

Methods And Analysis: This is a prospective, multicentre, cohort study including adult unselected EMS patients with chest pain. Data is being collected from 20 May 2023 to 31 December 2025, aiming to include at least 2,000 patients. High-sensitivity troponin I is being analysed bedside using Siemens Healthineers Atellica VTLi. In addition to prehospital troponin I, data is being collected on patient medical history, onset, vital signs, symptoms, ECG and diagnosis at hospital discharge. Several statistical analyses (random forest, logistic regression, gradient boosting) will be conducted to identify the best model for identifying patients with low-risk conditions suitable for non-conveyance.

Ethics And Dissemination: The study has been approved by the Swedish Ethical Review Authority (Dnr 2022-01066-01 and 2022-06846-02). Patients are being informed about the study both orally and in writing. The results of the study will be published in a peer-reviewed journal and will be presented at national and/or international conferences.

Registration Details: The study is registered at ClinicalTrials.gov (NCT05767619).