Factors of emergency medical services call delay and its impact on prognosis in STEMI patients: Findings from the CCA database-chest pain center registry

BACKGROUND: A delay in calls to emergency medical services (EMS) accounts for a substantial portion of prehospital delay, which may affect the prognosis of patients with ST-elevation myocardial infarction (STEMI).The objective of this study was to identify factors contributing to EMS call delay in patients with STEMI and evaluate the association between EMS call delay and in-hospital mortality. METHODS: A retrospective analysis was conducted between January 2020 and December 2023 from the China Chest Pain Center database. EMS call delays were described according to STEMI patients characteristics, and multivariable linear regression analysis was performed to explore independent factors related to EMS call delays. Locally weighted regression (LOESS) was used to fit the trend of mortality with EMS call delays. Logistic regression was used to analyze the relationship between EMS call delay and in-hospital mortality. RESULTS: This study included a total of 115,113 STEMI patients. The median EMS call delay time was 46 min. Subgroup analysis revealed that characteristics associated with an EMS call time exceedi ng 60 min included age ≥ 65 years, female sex, non-persistent chest pain/tightness, and nighttime symptom onset. Cardiovascular mortality, in-hospital mortality, and the incidence of in-hospital complications all exhibited a linear positive correlation with EMS call delay time. The independent risk factors for EMS call delay were age, female sex, non-persistent chest pain/tightness, and nighttime symptom onset. CONCLUSIONS: Public health initiatives should focus on older adults, females, and individuals with nighttime symptom onset or nonpersistent chest pain to promote timely EMS activation and reduce mortality.