Abstract 4141561: Impact of Snowfall on Emergency Medical System and In-hospital Mortality in Patients with Acute Coronary Syndrome

Background: Acute coronary syndrome (ACS) requires rapid transportation by the emergency medical system (EMS) and emergent percutaneous coronary intervention (PCI). In snowy areas, traffic conditions due to snowfall may delay EMS transport times and increase short term mortality of ACS. However, there is a paucity of data showing how snowfall affects the EMS and clinical outcomes in patients with ACS. We sought to investigate the impact of snowfall on the EMS transport time and in-hospital mortality in patients with ACS. Methods: We examined 2,387 consecutive ACS patients who were transported via EMS to 29 acute cardiac care facilities in Sapporo city (fifth largest in Japan) between April 2013 and March 2023. The patients were divided into two groups according to hospital arrival at snowy or non-snowy day. Results: The median age was 68 years, 1,754 (74.6%) patients were male, and 34.9%, 70.1%, and 69.2% had diabetes mellitus, hypertension, and dyslipidemia, respectively. There were no significant differences in gender, Killip classification, blood pressure, heart rate, or laboratory findings between the groups. Patients in snowy day group had longer time from EMS call to hospital arrival than those in non-snowy day group (33 [26–40] vs 29 [24–36] min, P <0.001). Quantity of snowfall was associated with a delayed time from EMS call to hospital ( Figure ). The proportion of emergent PCI and door-to-balloon time were similar between the groups. In-hospital death occurred in 125 patients (5.3%). The proportion of in-hospital death was higher in snowy day group compared to non-snowy day group (4.6% vs. 7.3%, P = 0.011). The snowfall was independently associated with a higher incidence of in-hospital death ( Table ). Conclusions: The snowfall was significantly associated with prolonged transfer time in EMS and higher in-hospital mortality in patients with ACS. These findings are relevant for developing traffic obstacles prevention strategies and ensuring timely treatment.