Abstract Introduction Cardiac symptoms are one of the most prevalent reasons for emergency department (ED) visits [1], however most of these patients do not have acute cardiovascular disease. This leads to ED overcrowding which subsequently leads to worse patient outcomes and increased costs [2,3]. Attempts to reduce overcrowding have focused mostly on in-hospital triage. The Hollands-midden Acute Regional Triage – cardiology (HART-c) study uses a newly developed triage platform which includes live monitoring, real-time admission capacity, in-hospital data and cardiologist consultation for improved prehospital triage. Purpose The HART-c study aims to safely increase the percentage of patients with cardiac symptoms not referred to the hospital after emergency medical service (EMS) consultation. Methods Patients aged 18 years or older visited by the EMS for cardiac symptoms were included in the region Hollands-Midden from September 2019 till March 2020 (non-COVID period) and compared with the year earlier. Patients were excluded when primary PCI was indicated. EMS consultation consisted of medical history, physical examination, vital parameters and ECG. All data were transferred to a newly developed platform combining pre-hospital data, shown in real-time, and hospital data, such as medical records and admission capacity. The paramedic contacted an on-call triage cardiologist and decided whether admission was necessary and, if so, which regional hospital was most appropriate (figure 1). The study objective was defined as the percentage of patients not referred to the hospital after EMS consultation. Safety of the triage method was defined in the non-referred patients in the intervention as the percentage of MACE (death and acute coronary syndrome) 30 days after non-referral. Results In the intervention group 1755 patients (age 69±15 years, 53% men), and in the control group 1629 patients (age 68±15 years, 53% men) were consulted by the EMS during the HART-c study. In the intervention group 11.4% of patients consulted to the EMS were left at home, compared to 5.5% in the control group (figure 2). Logistic regression was performed to evaluate the effect of the triage intervention. The model was corrected for gender, age and seasonal changes. The chance of being left at home after EMS consultation was 2.29 (95% CI 1.73–3.02, p<0.001) times higher in the intervention group compared to the control. All patients left at home in the intervention group and their GP's were contacted for adverse events, after case-by-case review the MACE rate was <1%. Furthermore a decrease in interhospital transfers was seen, from 206 in the intervention to 173 in the control. Conclusion Implementation of an innovative triage method successfully increased the percentage of patients with cardiac symptoms safely left at home. Funding Acknowledgement Type of funding sources: None. Triage without (A) and with (B) platformNon-referral in intervention and control